THE ELGI MAGAZINE 1

THE ELGI MAGAZINE 2

Send in your letters faxes and e-mails to:

THE ELGI MAGAZINECorporate CommunicationsELGI Equipments Ltd..Trichy Road Singanallur,Coimbatore - 641005Ph: +91-422-2589555Fax : +91-422-2573697E-mail: [email protected], [email protected] version available at www.elgi.comShould you require reprints of any of the articles,Please contact Elgi Corporate Communications.

VOLUME 9 APRIL 2013 - MARCH 2014

MANUSCRIPT AND ARTAuthor:Mr. Kumaran Sathasivam

Layout Design and Editing: Straight Curve Advertising, Chennai

Printed at:THE SAFIRE OFFSET PRINTERS, SIVAKASI

Image Courtesy:commons.wikimedia.org, www.shutterstock.com,www.istockphoto.com

EDITORIAL NOTE

Dear Reader,

How satisfying it is to produce an edition of this magazine!

It is no exaggeration to say that the experience of selecting the topics itself is akin to that of ‘a kid in a candy store’. It seems unlikely, but compressors can actually inspire poetry! The greatest number of articles has traditionally been related to the use of compressed air in shaping our world, in making the products and materials we use, and this issue is no exception. Countless are the applications of compressed air, and each one of these applications has a fascinating story behind it. Which stories does one select to present to you?

Articles in the present issue look at highly diverse topics. In one, you will see how compressed air makes aircraft safer; in another, you will learn about the role that compressors have in producing beverages. One article is about how compressors prevent landslides, another is about a role that these machines have in generating renewable energy. Surgical gloves, football, fibre optics, power plant, tug boats... compressed air touches them all. Find out how by reading the articles in this magazine.Read on, and in our Nature and Compressed Air series, you will find an article on what must be the most singular compressor anywhere. Another series is on the Nature destinations around Coimbatore. This time, the BR Hills, which abound in elephants and other large creatures, have been selected, but the focus is on some of their smaller residents.Products are constantly being developed at the Elgi companies. One section of the magazine is devoted to descriptions of the latest products. There is a photo feature on the use of the newest crash repair system from ATS Elgi.

There is much that is new about Elgi Equipments and it is going to sport a new look to match! We present a preview of this new look in this issue of Elgi Magazine. What do you feel about it? Which stories in this magazine did you like most? Do write to us.

Happy reading!

THE ELGI MAGAZINE 3

The late Mr. L.G. Ramamurthi, one of Elgi’ founders and its first Managing Director, designed Elgi Equipments’ familiar logo, with the word ELGI between parallel lines. This logo defined and identified the company in the Indian market for many years. Under this logo, Elgi has grown into a 235 million dollar company.This logo’s orange colour reflected the domestic orientation that Elgi Equipments had. It is not by accident that it reflects the saffron in India’s national flag.

Today Elgi has emerged as one of the largest manufacturers of air compressors in the world. The company’s global footprint is rapidly expanding and includes 70 countries, 20 offices and hundreds of distributors. The requirement of a new identify began to be felt—one that preserved its origins but also reflected its emerging realities.

A New Logo

The design team explains that the bold, solid lines represent security and solidity, traits of a global leader—traits that the modern world can depend on with confidence. The main colour is graphite grey, representing wisdom

and prestige. There is a splash of vibrant orange, standing for innovation. Of course, it also represents Elgi’s Indian heritage and its origins.. The grey provides an excellent foil, making the orange stand out.

The new logo will be the platform with which Elgi will fulfil its global aspirations.There are two other components to Elgi’s identity. One is UPTIMETM, a brand statement that will appear along with the name Elgi. This word refers to the promise offered by the Elgi brand. Elgi will keep a business running smoothly, efficiently and profitably. Elgi maximizes the UPTIMETM, of its products through design, choice of premium components and a very supportive assurance plan.The other component is the Forward Curve:

The graphic design shows the Forward Curve which represents movement symbolic of a company which is in motion. This represents the company which is evolving changing adapting and staying ahead of the curve. The Forward Curve will also appear on Elgi communications and elsewhere.

Welcome to the new Elgi. Visit us at www.elgi.com.

THE ELGI MAGAZINE 4

CON

TEN

TS

Poles ApartElgi Compressors contributing to the FIFA WORLDCUP 2014

6

Soil NailingKeeping the slopes of Cameron Highlands in pristine condition

14

Weight and ShotElgi Compressors keeping the skies safe!

20

Multiple FunctionsKeeping Beijing, pollution and garbage Free

26

THE ELGI MAGAZINE 5

CONTENTS

Great Big Air PillowsThe secret behind the launch of ships and tugboats!

32Elastic DemandElgi Compressors in the making of latex gloves

40Singular ApplicationStay connected with the help of Elgi Compressors

44On the Recovery of HeliumElgi Sauer Compressors in pursuit of Helium

52ATS Elgi Spanesi 106 Repairing crashed cars made easier

56

Paving the way forward with biofuels

60

A Spin in the County

Oil-free air for beverages!

66

Strange Combinations

Compressed air in Nature

72

One of a Kind

Travelogue

78

BR Hills with a Difference

New products

86

Engineering Solutions

THE ELGI MAGAZINE 6

POLESAPART

As Brazil warms up to host the 2014 FIFA WORLD CUP, Elgi Compressors are fast working to refurnish one of the greatest landmark in Brazil’s soccer history - The Maracana Stadium in Rio.

THE ELGI MAGAZINE 7

I wonder if I shall fall right THROUGH the earth! How funny it’ll seem to come out among the people that walk with their heads downward!—Alice’s Adventures in Wonderland, by Lewis Carroll

IMAGINE that we could create a passage through the earth. If we begin tunelling in India and excavate so assiduously that we perforate the globe, where would we emerge? The hole we create could well

open in Brazil: For all practical purposes, Brazil is situated diametrically opposite to India. In accordance with the laws of mathematics, just about any direction in this antipodean nation points towards India!

A vast distance separates India and Brazil, and it is only to be expected that the differences between them are considerable. Yet, there are similarities between Brazil and India. Both countries are primarily tropical. The equator actually passes through Brazil, but the country is so extensive that it stretches outside the tropics—it is the only country in the world to spread out so. In fact, Brazil is the fifth largest country in the world—and it will be readily apparent presently that there is some strange affinity between Brazil and the rank of five. India is close behind, at number seven, but the geographical area of Brazil is more than twice that of India’s: Brazil, around 8.5 million square kilometres; India, around 3.3 million square kilometres. Given this, it is uncanny that the length of the coastline of India is practically the same as that of Brazil: 7500 kilometres, give or take a couple of kilometres.

THE ELGI MAGAZINE 8

Both Brazil and India have different ecosystems within their boundaries, and both countries are among the 17 megadiverse countries of the world (a group of countries harbouring the majority of the earth’s species—the list was drawn up by Conservation International). One in ten known species in the world is found in the Amazon rainforest, which is located mostly within Brazil.

Both India and Brazil are rich in wildlife. However, there is little in

Brazil, No.5 !

common between their faunas in terms of species. India has large mammals such as the elephant, tiger, leopard, gaur, rhinoceros, sloth bear and sambar; Brazil is home to the puma, jaguar, anteaters, tapirs and armadillos. Similarly, the two countries have distinct avifaunas.

Just as with the geography, so too are there both differences and similarities between the cultures of the two nations. It is rather difficult to say which are more striking, the differences or the similarities.

The most obvious of the cultural differences is perhaps in the languages used by the two countries: Whereas India uses 22 official languages, practically the entire Brazilian population uses Portuguese. And Brazil is distinct

from all the American nations in this respect—all the other countries of South America use Spanish.

As with India, Brazil is a ‘melting pot’ of cultures. Various people have contributed to the lineage of Brazil’s people. At the same time, in the forests of the Amazon basin (the Amazon is the second longest river in the world and the largest river in respect of the volume of water flowing through it), there are native people who have not had contact with human beings from the ‘outside world’. According to one estimate, there are some 67 different tribes of these ‘uncontacted people’ in Brazil.

A person travelling from India to Brazil would find many food items common to the two countries. Rice is a staple in Brazil. Peanuts are

India has large mammals such as the elephant, tiger, leopard, gaur, rhinoceros, sloth bear and sambar; Brazil is home to the puma, jaguar, ant eaters, tapirs and armadillos.

Brazil is the fifth largest country in the world by geographical area.

It is also the fifth largest country by population. Brazil’s population was around 190 million in 2008, incidentally, around a fifth of India’s.

Brazil has the fifth largest economy in the world by nominal GDP.

THE ELGI MAGAZINE 9

consumed in significant quantities here, as is coffee. A number of fruits are grown and consumed in both the countries: guava, papaya, mango, orange and pineapple.

One significant cultural difference between India and Brazil is in the national sports. Whereas India is obsessed with cricket, in Brazil it is football that is a ‘rage and craze’.

The national football team of Brazil is claimed to be one of the strongest in the world. This is no idle assertion. The Brazilian football team started playing in 1914 and has appeared in all the 19 World Cup tournaments since 1930, the only team to have done

The prevalence of Portuguese is entirely due to Brazil’s history. In 1500, one Pedro Álvares Cabral, the commander of a Portuguese fleet, landed at Brazil. The humans he found there were all tribal and in a very primitive state. Cabral promptly claimed the land for his country. Colonisation effectively began in the 1530s, and very soon the Portuguese were cultivating sugarcane in Brazil, using slaves imported from Africa. The Dutch, the British and the French were also carving out colonies in the ‘new’ continent, and the Portuguese continued to expand their territories well into the 17th century. There were numerous military engagements between the various European nations on this soil.

The Dutch had much control over the sugar business. After a point, sugar exports declined, but just then, gold was discovered in Brazil, making the land even more valuable. At this time it was the Spanish who had a dominant role in the region. Eventually, Brazil went back to Portuguese rule. It is not commonly known that when Napoleon Bonaparte invaded Portugal in 1808, the Portuguese royal family established themselves in Rio de Janeiro. The city became the seat of the Portuguese empire, and the Portuguese Court was transferred to Brazil.

Dom João VI, the regent, returned to Europe in 1821, and Brazil declared itself independent the next year. There were battles throughout the territory, and eventually, in 1825, Portugal recognised the independence of Brazil.

Brazilian history and the Portuguese language

Brazil is the world’s 10th largest energy consumer (not number five here!). A significant part of the energy is derived from renewable sources—hydroelectricity and ethanol (from agricultural produce).

Brazil has 2500 airports. The only country to have a greater number of airports is the USA.

Brazil facts

POLES APART

THE ELGI MAGAZINE 10

so. Brazil is among the eight different national teams that have won the World Cup, having won it five times (there you are, the number five again), beginning in 1958, and most recently in 2002. This is the highest number of times that any team in the world has won the World Cup. The Brazilian team—one of its nicknames is Pentacampeão, meaning five-time champions—has had brilliant players such as Pele, Kaka, Ronaldo and Ronaldinho. Another of its nicknames is verde-amarela, meaning green-yellow, which refers to the colours of the team’s jerseys.

The team will be seeking to improve its World Cup record by winning a sixth tournament in 2014. The matches of the forthcoming tournament will be played on home soil, in Brazil.

The matches will be played at 12 venues. The largest of the stadia is the Maracanã, in Rio de Janeiro, which is indeed the largest stadium in South America. The stadium gets its name from the Maracanã River, which originates in hills to the west. The name Maracanã itself was used by indigenous people for a parrot which lived in the region.

The stadium was opened in 1950 to host the World Cup. Work on the stadium had not been completed when the matches began, but they

The Brazilian team—one of its nicknames is Pentacampeão, meaning five-time champions—has had brilliant players such as Pele, Kaka, Ronaldo and Ronaldinho.

POLES APART


If it is difficult to find words to describe the intensity of India’s infatuation with cricket, then it is impossible to convey Brazil’s passion for football. Children in Brazil may start playing the game on the beach, where the ball does not travel at all, and develop stamina in the process.

Football fans in Brazil attach themselves to a club each. Their support goes very deep, and fans make personal sacrifices for the club. They may travel with the club. The victory of one’s club is a matter of personal honour, and a team will be defended very personally by its devotees.

Much money is spent by the clubs—the Brazilian clubs are said to be next only to the English and European football leagues in terms of the money spent on the players. Diverse products are branded with club names, beginning with T-shirts and drinking cups.

Needless to say, the celebrations are exuberant when a club wins. According to one description, the celebrations that take place when India wins a cricket World Cup are unenthusiastic in comparison with the celebrations seen in Brazil when one club beat another in a game of football.

The Football Culture of

BRAZIL


were played anyway, and at the Maracanã, Brazil played Uruguay in the final game. Brazil lost that game. The number of standing spectators was close to 200,000 at this final game.

Subsequently, the Maracanã has been used mainly for football matches between the larger football clubs of

ELGI in BrazilIn 2009, Elgi launched a fully owned subsidiary company to meet the increasing demand for its products in Brazil. This company is called Elgi Compressores Do Brasil. It is engaged in selling and servicing electric and diesel screw compressors and has a wide network of distributors in Brazil and other Latin American countries.

As the Maracanã gets upgraded for 2014 and beyond, an Elgi machine supplies compressed air for sandblasting and painting steel structures of the stadium.

Rio de Janeiro. The construction work was well and truly completed only in 1965. In 1969, Pele scored his 1000th career goal at the Maracanã, against Vasco. Twenty years later, Zico, playing for Flamengo, scored his record 333rd Maracanã goal.

Other sporting events, music concerts and other events have been held occasionally at the Maracanã.

The stadium is undergoing major reconstruction for the 2014 World Cup. The Maracanã will also be used for the opening and closing ceremonies of the 2016 Summer Olympics and the 2016 Summer Paralympics. With a new seating arrangement, its capacity will be reduced to 76,804 (it had become an all-seater stadium after its 50th anniversary). The roof of the Maracanã will be expanded to cover all the seats in the stadium.

As the Maracanã gets upgraded for 2014 and beyond, an Elgi machine supplies compressed air for sandblasting and painting steel structures of the stadium. Evidently, the cultural similarities between India and Brazil are increasing! n


ADV E R T I S EMEN T


Soil Nailing

In Malaysia, Elgi compressors are aiding in the battle to keep the slopes of Cameron Highlands intact .


THE ‘CAMERONS’ is a plateau in Pahang, the largest state in peninsular Malaysia, and

it is a popular tourist destination in that country. According to one description, the Cameron Highlands are known for their tea estates, orchards, nurseries, waterfalls, mossy forests, wildlife, a golf course and a museum, apart from places of worship, hotels, bungalows and the Orang Asli, aboriginal people. Above all, the Camerons have a cool climate, providing escape from the heat of the lowlands of Malaysia.

The Cameron Highlands are located about 200 kilometres from Kuala

Lumpur, and they extend over more than 700 square kilometres. The altitude of the tableland ranges from 1200 metres to 1500 metres. As a result, the temperature in this tropical location ranges through the year between 9 and 25 degrees Centigrade. There are some mountains here rising to more than 1800 metres. There is abundant rainfall in all seasons. January and February are the ‘driest’ months, but there are really no dry seasons.

With a population of around 40,000, much of the Camerons is forested. Visitors can reach the highlands only by road. They can use the existing network of tracks

to discover ‘scenic spots, waterfalls and aboriginal villages’.

The composition of the forests changes with the altitude, and on the whole there are hundreds of plant species in the Camerons, many of which are rare. As may be imagined, the fauna is also rich. In the 1950s and 1960s, the area was declared a sanctuary for wild animals. Among the birds and mammals that are found in the Camerons are the Malayan whistling thrush, the mountain peacock-pheasant and the Sumatran serow, all of which have been classified by the IUCN in the Threatened category.


The Cameron Highlands were ‘discovered’ only in 1885, when a British surveyor was commissioned by the colonial government of those days to map the area between the states of Pahang and Perak. He was Sir William Cameron, and the place he discovered in the jungle was known as ‘Cameron’s Land’. In Cameron’s words, he saw a ‘vortex in the mountains’, with gentle slopes and plateau land over a wide area. As in several such instances in India, when the British administrator of the region heard

about this, he wished to establish a ‘sanatorium, health resort and open farmland’ here. But decades passed before the Cameron Highlands were established as a hill station.

A key development was the establishment of the Agricultural Experiment Station in 1925 to confirm whether tea, coffee, fruits, vegetables and cinchona could be grown in the district. The next year, with the feasibility of cultivation of tea having been confirmed, a committee was formed to identify areas of the highlands for cultivation, housing, administration and so forth. A private firm was awarded a three-year contract to build a road to the plateau from Tapah, a town on the road from Kuala Lumpur to Ipoh.

Construction of the road began in 1928. The project was completed towards the end of 1930, a few weeks ahead of schedule, despite challenging conditions. The crew had to cope with the weather and

Clockwise from top: a waterfall, the highway from Selangor to Ipoh, Strawberry farm , Centre: Sir William Cameron Bottom right: Sumatran Serow, Peacock Pheasant


with malaria. Hundreds of workers were hospitalised with the disease. Great difficulties were experienced in hauling the heavy equipment up to the higher altitudes. Steam-driven locomotives were used to pull it up steep gradients.

The opening of the road in 1931 led to people moving in and settling on the mountain slopes. Tea plantations were established, and vegetables were grown. Within a few years, cottages, schools, a dairy, nurseries, a military camp and a golf course came up. Growth continued until the Japanese occupation of the 1940s, during the Second World War. After Malaysia obtained independence, extensive stretches of forests were cleared for agriculture and for developing infrastructure.

Today, highway and hillside development projects continue to be carried out in Malaysia. In the undulating terrain of the Cameron Highlands, slopes grow ‘distressed’

Today, highway and hillside development projects continue to be carried out in Malaysia. In the undulating terrain of the Cameron Highlands, slopes grow ‘distressed’ with time.

with time. Further, very steep slopes are created as access is provided to areas such as dam sites and working spaces are expanded. In this rainy region, there is a risk of the slopes collapsing after a wet spell. These slopes need to be ‘stabilized’.

Commonly used retaining systems such as concrete walls require inordinate earthwork. Engineers have therefore opted to use the technique of soil nailing to strengthen slopes. This method has grown popular because it is easy to implement because little maintenance is required subsequently. The earthwork required is minimal, and the risk involved during the work is low.Soil nailing, as a technique for stabilizing slopes, is said to have been used first in 1972 in France. It is now used around the world.

The soil nailing method gets its name from the ‘nails’ which are driven into the soil, beginning at

the top of a slope and proceeding downwards, as excavation is carried out. These nails are slender elements such as the reinforcing bars (or rebars) used to strengthen concrete. Other kinds of solid or hollow nails are also used. They typically have a length of one foot. The nails are set in place at regularly spaced horizontal and vertical locations all over a slope. They are grouted into place, and a rigid facing is provided over

SOIL NAILING


The air drives soil nails at speeds exceeding 350 kilometres per hour. A high-velocity shock wave is generated ahead of an accelerated nail, and the soil deforms elastically around it. It rebounds subsequently and bonds with the nail.

the surface of the slope. Usually, this rigid facing is pneumatically applied concrete, alternatively known as shotcrete. Sometimes, a flexible reinforcing mesh is used additionally or in place of concrete. A pipe of around 12 metres’ length is introduced into the soil at the bottom of the slope to drain water and reduce the pressure on the facing.

Soil nails may also be used to stabilize embankments and retaining walls. Where solid nails are used, they must be inserted into pre-drilled holes. Grouting is provided using a separate grout line to secure them. Hollow nails, on the other hand, may be introduced using sacrificial drill bits. Grout is pumped through the hollow bars as drilling proceeds.

Soil nails may also be fired into the earth using an air cannon. This is mounted at the end of an excavator’s articulated boom. Compressed air from an auxiliary air compressor is used in this system. The compressor is mounted on the rear of the excavator. The air drives soil nails at speeds exceeding 350 kilometres per hour. A high-velocity shock wave is generated ahead of an accelerated nail, and the soil deforms elastically around it. It rebounds subsequently and bonds with the nail.

Apart from drilling, air compressors are used in the concrete spraying process. Two streams are directed at the face of the slope in this process. One stream consists of a mixture of cement and sand, carried along in a flow of compressed air. The other stream is a jet of water. They meet at the spraying point, producing concrete.

Thus compressors are used in the drilling, grouting and cement blowing applications in soil nailing.

North Soles, a Malaysian firm, routinely uses Elgi diesel powered air compressors for soil nailing. North Soles finds that the use of compressed air meets the demand for faster drilling and ensures higher productivity at a lower per-foot drilling cost.

Soil nailing has been proved to be highly cost-effective in various conditions, for both new excavations and for stabilization and repair of existing slopes. n

Soil Nail


WEIGHTAND SHOT

A glimpse into how Elgi Compressors are making aircrafts safer..


WEIGHTAND SHOT THE TERM ‘ROCKET SCIENCE’ is now applied to

any technology in which complex technical and mathematical components are involved. It is also

used often in the expression ‘it is not rocket science’, indicating that something is simple. A ‘rocket scientist’ is a person of great intelligence. The reason for this is the fact that flying vehicles operate under demanding conditions. Hence ‘rocket science’—which should properly be called aerospace engineering—involves an interaction of a number of disciplines: physics, materials science, fluid mechanics, avionics, computational fluid dynamics, manufacturing technology, structural analysis and others.

Aerospace engineering is involved with the design and construction of aircraft and spacecraft. It was originally known as aeronautical engineering. The

new term was defined in the 1950s to include satellites and other craft that operate in outer space.

Developing and manufacturing a flying vehicle today is a very complex process. Large modern aircraft may be designed in offices and engineering centres in widely separated locations across the world. Multiple production sites may also be involved, with various sections being integrated finally. Pre-assembled components of the Airbus A380, for instance, travel by sea, river and road from locations across Europe to Toulouse. After systems are tested, the engines and cabin are installed. Fuel and pressurization tests are carried out, and painting is carried out. Flight testing is then carried out, followed by delivery. Today, the aerospace industry is one of the largest manufacturing industries in the world.

Aerospace engineering is involved with the design and construction of aircraft and spacecraft. it was originally known as aeronautical engineering. the new term was defined in the 1950s to include satellites and other craft that operate in outer space.


With compressed air being a utility (like water, power and light), it comes as no surprise that compressors find several uses both in aerospace engineering and on aircraft themselves. To give just one example of the latter, in a jet aircraft, compressors provide air to start the engine. To provide another instance, air compressors are used in mobile breathing systems in aircraft.

Compressors are used in many instances in aircraft manufacture. For instance, they provide an uninterrupted supply of compressed air to sophisticated milling machines. These machines need compressed air to power pneumatic arms that change tools and grip the work piece. The milling machines themselves are used to produce various aircraft components.

In the making of aircraft wings, air compressors find a critical application. The function of a wing is, as is well known, to create a lifting force (simply referred to as ‘lift’) which keeps the aircraft aloft.

The lift is produced as a result of the shape of the wings and their orientation (‘angle of attack’) with respect to the airflow past them. The shape of a wing in cross-section is called an aerofoil shape or profile. This shape is such that it modifies the airflow. The air speed across the surface of a wing changes from one point to another. As a result, in accordance with Bernoull’s Principle, the air pressure is also different at different points on the wing. On the whole, the pressure above the wing is reduced below the normal

air pressure, and a region of higher pressure forms below the wing. The net result, naturally, is a force that pushes the wing up.

The action of the wing could also be understood as a downward deflection of the

airflow, a ‘push’. There is a corresponding reaction, an upward push of the air on the wing. At any rate, it must be borne in mind that the shape of the wing is of utmost importance and must be preserved at all times—at least, this is true for ‘fixed-wing aircraft’, a term which applies to most modern aircraft.

Most modern aircraft have all-metal wings, with aluminium having been the metal of choice for decades. A metal wing has a box-like structure, with an outer covering known as a skin. The major members of the framework, known as spars, extend lengthwise. Spars are essentially like the beams in a building or any other structure. There are typically two spars in a wing, but there may be up to five spars in some wings. There are a number of stiffeners that run between

The Bernoulli’s Principle of Flight

The Wing Structure


The oscillating stresses to which aircraft are subjected routinely are a great source of worry to aerospace engineers because such stresses give rise to the problem of fatigue.

the leading and trailing edges of the wing. These are known as ribs, and they provide the wing its aerofoil shape. There may be longitudinal members other than the spars. These are much slimmer and are known as stringers. The skin is fixed on the framework of spars, stringers and ribs.

The various structural members are held together at the joints using rivets and bolts. Friction at the rivet-hole interfaces damps vibrations. Arc welding is not used because the aluminium is subjected to rolling and heat treatment to create desirable properties. The high temperatures of arc welding destroy these properties. Spot welding is rarely used.

It has been mentioned that reducing the weight of the aircraft is a fixation of aerospace engineers. One of its manifestations is a provision of lightening holes in the ribs. Where bolts are used, their diameter is tapered from many millimetres at the root to just 3 or 4 millimetres at the tip. The thickness of the skin is reduced by chemical milling wherever the stress is less and the metal is not bearing as much load as

it could. Thus there may be four or five thicknesses on a single skin. Regions of one thickness may be no larger than the palm of one’s hand, and the difference in thickness between one section and the next may be just one millimetre. Aerospace engineers expend considerable effort in locating lightly stressed areas! All these measures save considerable weight. However, all aircraft structures are designed with great care because human life depends on how they perform.

The design of an aircraft is such that when it is in level flight, the lower skin of the wings experiences tension (it is stretched) and the upper skin is in compression. But this loading of the wing is hardly steady. Particularly during turbulent weather, the loads on the wings change rapidly. As a result, the wing components experience vibrations and oscillations. The oscillating stresses to which aircraft are subjected routinely are a great source of worry to aerospace engineers because such stresses give rise to the problem of fatigue.

When a structure is subjected to repeated loading and unloading, or where the loading changes repetitively

WEIGHT AND SHOT


Wing parts are subjected to shot peening after they are machined from aluminium blocks and sheets. This crucial operation improves the fatigue strength of the wings.

from compression to tension and vice versa (cyclic loading), there is localized damage which becomes progressively worse. This damage is referred to as fatigue. Under cyclic loading, the material fails below its normal stress limit. The damage begins in the form of microscopic cracks at points of stress concentration such as sharp corners and square holes. The cracks reach a critical size after a stage, and the entire structure fractures. Fatigue cracks typically develop at the surface of a structure when it is subjected to a tensile stress; they are less likely to start in the interior.

The fatigue life of a metal part can be improved, sometimes greatly, by treating it by shot peening. This is a process in which small metal bits (‘shots’), typically the ‘size of poppy seeds’, are fired at it. The shots may also be of glass or ceramic. The process gets its name from the fact that the shots act like the blows of a miniature ball-peen hammer. They deform the surface of the part permanently when they strike it. In the process, they change its material properties. They leave beneficial compressive stresses on the surface of the part, thereby impeding crack growth and improving the fatigue strength.

Compressed air is used to drive the shot in peening, rather as sand is propelled in sand blasting. But instead of abrading the material, the shot deforms it. As a result, little material is removed in the process.

Wing parts are subjected to shot peening after they are machined from aluminium blocks and sheets. This crucial operation improves the fatigue strength of the wings.

Elgi compressors are used by aircraft companies for shot peening and other application.

n

From top : the stress readings on aircraft wings, the microscopic cracks ,shot peening

WEIGHT AND SHOT


2557 square kilometres, is 60 times larger than the former.

Beijing is very large in terms of population as well. The city’s population is 16.3 million according to the aforementioned source and 20.69 million according to another. That is a large difference between the two figures, but there is no denying that Beijing is a very populous city. And it is predicted that the population will continue to grow in the future.

Beijing has taken various efforts to bridle the problems that have accompanied this urbanization, notably heavy traffic and poor air quality. When the city was preparing

for the 2008 Olympic games, many factories were closed, and work was halted at all construction sites. Drivers were limited to using their cars on alternate days, depending on their license plate numbers, thereby halving the traffic. Other measures included staggering office hours and retail opening times to reduce rush hour traffic and introducing two new subway lines to encourage the use of public transport.

The measures to curb pollution have continued after the Olympic games. Improved emission standards have been brought in for vehicles. Many thousands of vehicles that do not comply have been banned from

A BANK OF Elgi Compressors is in operation in a place in China called the Mentougou

District. Mentougou falls in the Beijing Municipality and is technically a part of the capital city.

Beijing, located to the north of China, is enormous. According to one source, it spreads over an area of 16,808 square kilometres, considering which, it ‘is large enough to be treated as a province in its own right’. For purposes of administration, Beijing is divided into 14 districts and two counties. These range in extent from Dongcheng District, the smallest (40.6 square kilometres), to Huairou District, which, with an area of


the city. Trees have been planted in hundreds of thousands. Beijing’s fleet of buses running on natural gas is said to be one of the largest in the world. It is reported that even after all these measures the pollution levels remain intractable.

No doubt the urban area is the most problematic in this respect. It occupies a relatively small portion of the municipality’s area and lies in the south-central part. Around

it are many satellite towns. To the east and south of Beijing is the North China Plain. In the north and west are mountains. The highest point of these mountains rises 2300 metres above sea level.

Mentougou District is somewhat different from the metropolitan part of Beijing. Most of its limits are within the Western Hills. Roughly 93 percent of the district has a mountainous terrain. There

Multiple FunctionsAn array of Elgi Compressors in Mentougou is helping to improve the air quality while generating power from garbage incineration

are around a hundred peaks in Mentougou. With an area of more 1300 square kilometres, the district is medium-sized by Beijing standards. Given this, its population, just 270,000 at the beginning of the new millennium, is surprisingly small. With just 218 humans per square kilometre, Mentougou has one of the least densities among Beijing’s county-level administrative units. (In contrast, Dongcheng District has close to 23,000 people per square

Mentougou


kilometre, and in Xicheng District, there are more than 26,000 people per square kilometre. A quick calculation indicates that if all these people were made to stand apart at a regular spacing, each person would get 38 square metres, or a plot measuring 20 feet by 20 feet or so.)

Mentougou District remained only technically a part of Beijing till recently. Even today, as in the past, much of Mentougou is rural in essence. It supplies Beijing with fruits and vegetables apart from roses and mushrooms. Only the eastern section of the district is urbanised.

But Mentougou has not been entirely agricultural. It is richly

endowed with mineral resources: granite, coal, limestone. Mining was an activity in Mentougou when the Ming Dynasty ruled China (14th century to 17th century CE). More recently, there has been considerable mining in the district, with a number of large companies operating here. With the depletion of deposits, some of them have stopped.

And now there are changes taking place. Tourism is becoming an important activity in rural, scenic, mountainous Mentougou. People come to visit the temples of Miaofengshan (a town named after a mountain), Tanzhesi (Temple of the Poor and the Wild Mulberry) and Jietaisi (Temple of the Ordination Altar). They come

to picturesque Linghsan Mountain, with its wildflower-clothed slopes and its views, which ‘in general have taken a definite lean towards the dramatic’. And they come to see Chuandixia, a village founded during the days of the Ming Dynasty and known for its well-preserved courtyard homes.

So this is Mentougou District, a place in transition. In this district, there is a power plant. Like Mentougou, the plant has multiple as pects to it. It is in this power plant that the Elgi compressors are being used.The power plant in question (1) generates energy, (2) serves as a waste disposal facility and (3) produces building material. Constructed on a 66,000 square metre site, the plant uses an


unusual fuel: garbage. It generates power by burning 3000 tons of garbage each day.

Solid waste is burnt in a combustion chamber, and the heat generated is used to generate steam at a high temperature and pressure. The steam drives turbines and produces electricity. This is a seemingly simple, good way of disposing of unwanted garbage and meeting energy demands at the same time.

Actually, it is fairly complex. A host of processes and technologies are involved. The complexity arises from various factors. For instance, not all garbage can be used as fuel in a plant of this kind. Power generation equipment will function only if the solid waste consistently has sufficiently high calorific content. If the calorific value of the refuse-derived fuel (RDF) is less than a minimum value, it becomes more complicated and less economic to run the power

plant. The garbage that goes into the combustion chamber must therefore be separated according to calorific value. This can be done using a combination of manpower and machines. In some municipal solid waste incineration systems, the waste is converted into briquettes and burnt in a boiler. In some technologies, various lots of briquettes are pulverized and blended so that the quality of the fuel is more homogeneous for combustion. Just before combustion, the pulverized fuel is atomised. Briquettes are more commonly burnt directly.

The facility at Mentougou has four lines with a processing capacity of 750 tons of garbage each. The garbage is collected, separated according to type and pretreated before it is burnt. The burning takes place in a moving grate incinerator. In this machine, the garbage is conveyed through the combustion chamber by a moving grate. Some

air is supplied for combustion from below the grate. Additional air is supplied through nozzles over the grate. The air coming from below the grate cools it. This is important for ensuring that the grate does not overheat and lose its strength.

Heat from the incinerator is extracted to produce steam, and this runs two 30 megawatt turbines driving electrical generators. Thus the plant has a fuel supply system, thermal control system, water treatment system and other supporting facilities.

But then there is the problem of ash and pollution. The flue gases (gases leaving the combustion chamber through a flue, or channel in a chimney) contain oxides of nitrogen (NOx), the levels of which depend on the garbage quality. NOx are harmful to the health of humans and in general to all living things. These materials are directly related to acid rain, corrosion of

The facility at Mentougou has four lines with a processing capacity of 750 tons of garbage each. The garbage is collected, separated according to type and pretreated before it is burnt. The burning takes place in a moving grate incinerator.

MULTIPLE FUNCTIONS


steel structures and erosion of stone buildings and statues.

Even more dangerous substances such as dioxins are formed during the combustion process. These compounds are very toxic and produce a range of problems. They also cause cancer.

Ash is the solid product of combustion in the incinerator. It is produced in large quantities. It is in the form of bottom ash, which does not rise with the flue gases, or in the form of fly ash, which is very fine and goes up with the flue gases. Fly ash is a pollutant and may be harmful to health. All the ash must be gathered and disposed of. These pollutants introduce further complexity in the plant. The Mentougou plant has facilities that ensure that these materials do not aggravate the air quality problems faced by Beijing. The plant uses more equipment and technologies for this.

Flue gas purification technologies include selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR). These methods are used to remove NOx.

The flue gases from the Mentougou plant have very low levels of NOx after treatment, on par with international facilities. In SNCR, ammonia or urea is injected into the combustion chamber at a point where the temperature of the flue gases is between 760 and 1093 degrees Celsius. The ammonia (or urea) reacts with the NOx, producing harmless nitrogen, carbon dioxide and water. In SCR, the NOx is converted into nitrogen and water, using ammonia or urea again, but a catalyst such as titanium oxide is used, and the reactions take place at a lower temperature.

The dioxins are removed using activated carbon, a form of carbon that has a large surface area on account of a very large number of pores. The dioxins adhere to the surface of the carbon and are thus extracted from the flue gases.

The fly ash is removed using cyclonic separators. In cyclonic separation, the flue gas is made to rotate at high speed in a cylindrical or conical container, known as a cyclone. The rotational effect and gravity cause the ash and the gases to separate. The solid ash particles

are too heavy to follow the tight curve of the stream. Thus they strike the wall of the cyclone and fall to the bottom, where they can be collected.

The collected fly ash is converted into building materials. It can be mixed with clay and fired in a kiln to produce bricks. It can also be added to a concrete mix to get building blocks.

The Elgi compressors are busy operating numerous pneumatic valves and other pneumatic devices in the Mentougou plant. They also supply compressed air to flush the ash collected by the separators, contributing to the efforts to improve the air quality. n

HOW IT WORKS A Moving Grate Incinerator

Top : a typical layout of a garbage incinerator power plant, Above: inside a moving grate incinerator

MULTIPLE FUNCTIONS


Great Big Air PillowsOVER the past several decades, international trade

has been growing vigorously. The value of world trade has increased 20 times since 1950. It has

been pointed out that this far exceeds the rate of growth of the world’s population. The burgeoning volume of goods involved is transported over land, by air and by sea. But the amounts involved in the different modes of transport are highly lopsided. The proportion (by weight) of goods transported by air is almost negligibly small, just 0.25 percent. Road and rail transport, favoured mainly in trade between neighbouring countries, carries far more, close to 10 percent of the volume of trade by weight. The dominant form of transport of goods, by far, is by ships. Ships have been carrying some 7 billion tons of goods annually in recent years.

Ships are larger now than ever before, with the number of commercial ships in the world with a gross tonnage of more than 1000 tons hovering in the vicinity of 35,000.


Deadweight

The deadweight of a ship is the weight it can safely carry, including cargo, fuel, passen-gers, crew, provisions, ballast and water


These include container ships, which may be close to 400 metres long, with capacities over 14,500 TEUs (twenty-foot equivalent units). Bulkers, which are typically used to carry goods such as ores and grains, come in a range of sizes, the largest of these having deadweights of 200,000 tons and more and lengths exceeding 200 metres. The largest of ships are tankers. They are used to transport oil, gas and chemicals. At one end of the tanker size spectrum are ships with deadweights in the range from 10,000 to 25,000 tons; at the other end are the ultra-large crude carriers (ULCCs), with deadweights exceeding 500,000 tons and lengths close to 500 metres.

As may be imagined, these large vessels need to be fitted with very powerful engines to turn their propellers in the water and thereby move. The RTA96-C, produced by Wartsila-Sulzer and said to be the largest marine

engine, generates a power output of more than 84,000 kilowatts (or 113,000 horsepower). Even with their large engines, cargo ships travel sedately as a rule, their speeds rarely exceeding 25 knots (46 kilometres per hour).

For all practical purposes, once these giants are set on a course in the open sea, they just need to keep travelling in a straight line. This they can do very well. But there come times when a ship must slow down, stop, turn or move sideways. These are things that a large ship cannot do well.

Ships have no brakes. For a ship to come to a stop, the engine power must be reduced and the propellers stopped so that the ship slows down through water resistance and drifts to a halt. Due to its enormous momentum, a ship will travel hundreds of metres before


Tugboats are far smaller than the vessels that they haul along or push about. They are typically 20 to 30 metres long. As such, they have very large power-to-tonnage ratios, even up to nine times those of cargo ships.

stopping. A massive supertanker may have a stopping distance of a few kilometres. The propellers of a ship may be able to provide reverse thrust (‘astern propulsion’) when the ship is moving forward itself, in which case the stopping distance is reduced. But even so, ships are not particularly quick to respond.

And it is difficult or impossible for these ponderous vessels to turn in tight circles. To turn using its own power, a large ship uses its rudder, and some forward motion is required for the rudder to be effective. A cargo ship moves in a radius of half a kilometer or more

GREAT BIG AIR PILLOWS


when it turns. And a ship simply cannot move sideways except when it is provided with devices known as transverse thrusters, more of which presently.

The limits of the manoeuvrability of a ship are never more keenly felt than when it needs to navigate narrow waters and when it must dock or cast off. In these situations, the ship needs the assistance of tugboats. These are relatively small vessels that are built specifically to manoeuvre larger craft.

Tugboats are veritable powerhouses. Being designed

to push or tow large ships, they need, of course, to be sufficiently powerful. Smaller tugboats are fitted with engines that can produce 700 to 3400 horsepower. Larger ones, used in deeper waters, may have ratings of up to 27,000 horsepower.

These engines are essentially the same as those used in railway locomotives. The thrust developed by a tugboat may be increased using Kort nozzles, which are cylindrical structures provided around the propellers. They improve the thrust by modifying the flow of water towards and away from the propellers.

Tugboats are far smaller than the vessels that they haul along or push about. They are typically 20 to 30 metres long. As such, they have very large power-to-tonnage ratios, even up to nine times those of cargo ships.

Tugboats are also extremely manoeuvrable. They owe this manoeuvrability to their being fitted with devices such as transverse thrusters and Voith Schneider propellers.

Transverse thrusters (referred to as bow thrusters or stern thrusters, depending on where in the hull they are installed) are essentially propellers that provide a lateral thrust to a ship when they operate. They may be driven by electric motors, hydraulic motors or diesel engines.

Tugboats are also extremely manoeuvrable. They owe this manoeuvrability to their being fitted with devices such as transverse thrusters and Voith Schneider propellers.


The Voith Schneider propeller is a marine propulsion system that can change very quickly the direction of the thrust it provides. It consists of a circular plate rotating in a horizontal plane, with a set of blades arranged around it. Each of the blades can rotate about a vertical axis. As the plate rotates, an internal gear changes the angle of attack of the blades synchronously, producing thrust in the required direction. By changing the orientation of the blades, the direction of thrust can be changed. The entire system is fitted below the bottom of the ship, and there is no need for a rudder when a Voith Schneider propeller is used.

Elgi recently supplied air compressors to tugboat builders in East Malaysia. What is an air compressor used in the building of a tugboat? There is more than one application, really. For example, the steel components (plates, frames, stiffeners) of which a tugboat is built must all be sandblasted to remove rust and dust prior to welding and painting. Air compressors are used

in this operation. To give another example, the water and fuel tanks of a tug (or any other vessel, for that matter) are tested under pressure to verify that the joints are strong and do not leak. Compressed air is used in such testing.

You will find a most interesting application of compressors in the launching of a tugboat. A ship is traditionally launched into the water by being made to slip down an inclined slideway. Oil or wax may be used to lubricate the slideway.

This is a simple means of launching, but there is a danger of the ship sustaining damage due to the high pressures that the hull experiences

during the operation. Alternatively, the friction between the ship and the slideway may be reduced by using steel plates and steel rollers or balls. This is a more effective means of launching a ship, but installing the launching system is expensive. To overcome the disadvantages of these two methods, a ship may be constructed in a dry dock and launched by filling the dock with water. The ship can then be floated out, without the risk of damaging it. The process is straightforward and simple. The drawback of this system is that the initial investment in a dry dock is high.

The tugboat builders of East Malaysia are using an innovative technique to launch the vessels

A ship is traditionally launched into the water by being made to slip down an inclined slideway. Oil or wax may be used to lubricate the slideway.



With the air bag system, the launch ends simply, with the ship rolling on the airbags and entering the water.

they build: they use airbags. These are cylindrical in shape and have hemispherical ends. They are constructed of layers of reinforced rubber.

The ship is built on a flat, clean piece of ground close to the water. The stern, the rear portion of the ship is closer to the water. The ship is built on rows of concrete blocks, so that the bottom of the ship is clear of the ground. Before the launch, the airbags are positioned on the ground between the blocks under the ship. The spacing between the airbags depends on the size of the ship. The airbags are inflated with air using compressors. Eventually they touch the ship’s bottom and support its weight. The blocks at the rear of the ship are removed. The ship then sits on the blocks at the stem (the forward end of the ship)

and the airbags. Next, the airbags at the stem are inflated further and those at the stern are deflated a little. As a result, the ship is tilted downwards towards the water. To initiate the launch, the ship is pushed a little using bulldozers.

The ship then starts to slide to the water on the airbags. They are firm enough to serve as rollers, but at the same time, they are soft enough to take the shape of the ship’s bottom, like great big air pillows. As a result, the area supporting the ship’s weight is quite large. The pressure that needs to be developed in the airbags is surprisingly low, considering the great weight of a ship. The working pressure specified by one manufacturer of airbags is no more than 2.1 bar. Thus to inflate them, the shipyards use the same compressors that

they use for sandblasting—these can develop pressures of 7 bar or more. The launch ends simply, with the ship rolling on the airbags and entering the water.

The airbags that enter the water during the launch are recovered using a small vessel, brought ashore and deflated. They are deflated by opening valves, and then they are folded up for re-use.

This new technique is gaining popularity in China and other places apart from Malaysia. The reasons are obvious: there is no need for a slideway or dry dock; it is safe and reliable; it is economic; and it is quick. Even fairly large vessels, those with deadweights up to 55,000 tons, are being launched using airbags.

n



Elastic Demand

Rubber finds wide use because of its unique physical and chemical properties. It can stretch greatly, it is highly resilient, and it is entirely waterproof. These properties confer corresponding qualities and a long life to any product.Rubber is chemically inert on the whole. It does not react with water or weakly acidic and alkaline solutions. It can therefore serve as a protective coating. However, rubber is chemically broken down by naphtha and turpentine.

Rubber derives its physical properties from the structure of its molecules. It is polymeric (the molecules are like long coiled-up chains), and there is a double bond in every repeat unit. The bonds can withstand considerable distortion, giving rise to the elastic behaviour of rubber. When a force is applied, the bond lengths deviate away from the equilibrium (the point of minimum energy), and strain energy is stored thermally. When rubber is stretched, the chains become tight and their energy is released as heat. This behaviour is different from that of many other materials, which store the strain energy electrostatically. The process of vulcanizing turns rubber from a thermoplastic substance into a rigid thermoset. Rubber in everyday use has the properties of both a thermosoftening plastic and a thermoset. If it is heated and cooled, it is degraded—but it is not destroyed.

Properties of Rubber

A NATURAL MATERIAL WITH A SYNTHETIC VERSIONStudents of economics inform

us that we live in an age in which the production and consumption of goods are much higher than ever before. In order to produce goods at this unprecedented level, we are using natural resources at a correspondingly high intensity. We use nearly every type of natural material that is available to us in producing our goods. Minerals, metals, wood, water, soil: we use them all. And in working these materials into the goods that we use, we invariably use compressed air.

One of the widely used natural materials is rubber. Look around

you, and you are sure to find that rubber has been used in one form or the other in most of your belongings. This material even has a synthetic version.

The use of rubber can be traced to a long time back. The ancient Olmecs, who lived in parts of Mexico for around a thousand years, starting from 1500 BC or so, made rubber balls. They must have played games with them—surely, they must have been uncommonly unimaginative if they did not! Anyway, they probably made these balls by simply collecting latex from rubber trees and boiling it. The most usable latex is obtained from a tree called the para rubber tree—Hevea brasiliensis to give it its scientific name. Other


plants, notably those of the family Euphorbiaceae, too yield latex that can be used to produce rubber, but they are usually difficult to tap. And making rubber using the latex that they do yield involves elaborate processing.

The latex is obtained by making incisions on the bark. The fluid (milk-like in its whiteness but rather more sticky) that issues forth is collected in vessels. Latex is a colloid in the fresh condition, and if it is stood for long enough, it will coagulate into a mass that cannot be processed into anything useful. The trick is to coagulate the latex under controlled conditions. The resulting material must be cleaned, prepared and dried before it can be used in manufacture.

Synthetic rubber is made from petroleum products. Millions of tons of rubber are used annually worldwide, around two-thirds of this being synthetically made rubber. Indeed, most products of daily use include the synthetic form of rubber.

Rubber, as has been hinted at, is used in both household and industrial products. Tyres and

tubes rank as the greatest use of rubber today. Other significant uses of rubber include shoes, gloves (medical, household and industrial), toy balloons, rubber bands and pencil erasers.

There are some applications, however, in which synthetic rubber cannot be used in place of natural rubber. Consider medical gloves.

A tight fitMedical gloves are essentially gloves that are used for medical examinations and for other activities that require a high level of hygiene and precision. These gloves are of the disposable type. There are two main types of these gloves: examination gloves and surgical gloves. The requirements of surgical gloves are more demanding. Examination gloves do not have to fit exactly, but the need for precision and sensitivity means that surgical gloves need to fit precisely and that they need to be made to more stringent standards.The first pair of disposable latex medical gloves was created in 1964. Since then, the uses to which these gloves are put have grown greatly to include cutting and cleaning vegetables and meat at restaurants

and dental applications. Surgical gloves are very thin, and they need to have a tight fit. They do not reduce the dexterity of the fingers of the wearer. Criminals have been known to wear these latex gloves when committing their offences under the impression that they will not leave traces behind. But these gloves are so thin that they do tend to transfer the fingerprints of users on surfaces touched by them.

The latex used to manufacture natural rubber contains some proteins that produce an allergic reaction in some users. But even though vinyl, nitrile rubber and neoprene (all synthetic substances, the last two being synthetic rubbers) can be used to make gloves, surgical gloves continue to be made of natural rubber. The gloves made of the synthetic substances simply do not give the fine control or greater sensitivity of touch of natural rubber gloves.You could use rubber made of high-grade isoprene to make gloves. The molecular structure of this substance is almost identical to that of latex. But this material happens to be a particularly expensive alternative. Another solution is to treat natural rubber so that the

ELASTIC DEMAND

The trick is to coagulate the latex under controlled conditions. The resulting material must be cleaned, prepared and dried before it can be used in manufacture.


amount of allergenic proteins in it is reduced, but even this is very expensive.

Four stepsThere are four major steps in the process used to manufacture gloves using natural rubber:

1. Dipping. In the first step of the production process, the liquid latex concentrate is mixed with a number of various compounding chemicals. It is then introduced into tanks. ‘Formers’, objects made in the shape of hands, are immersed in the latex-chemical mix. The formers need to be cleaned and dried first and coated with a coagulant before they are dipped in the mix. The coagulant causes a layer of rubber to be deposited on the former. The formers are kept immersed in the latex for a period according to the desired thickness of the latex coat.

2. Drying and curing. The gloves (along with the formers) are lifted out of the tanks containing the latex mix. The gloves need to be dried and vulcanized next. Hot-air ovens are used for drying and curing them. The ovens are

initially set at a temperature of 80 to 90 degrees Celsius. As the drying and curing proceeds, the temperature is slowly raised to 100 to 140 degrees Celsius. This temperature depends on the thickness of the gloves.

3. Powdering. The gloves (and formers) are now removed from the ovens and dipped into a slurry of corn starch. The starch acts as a lubricant and makes it easier and faster for a wearer to don the gloves.

4. Glove stripping. This the final stage in the production line. As its name suggests, it is the stage in which the gloves are removed from the formers.

Last but not the leastSo in which step or steps of glove production is compressed air used? Compressed air is used in the final step of glove stripping. The gloves could be removed manually from the formers before they are packaged and

sent off for sales. But it is far more expedient to use compressed air to ease the gloves off the formers. Compressed air is also used in testing medical gloves to ensure that they meet Acceptable Quality Level (AQL) standards. The gloves are inflated with compressed air and inspected visually for holes. It is critical for medical gloves that they be tested using compressed air from oil-free compressors.

n


Singular Application

What you see is a seamless network of mobile phones!But what you don’t see are the Elgi compressors which help lay the optic fibre cables that keep you connected 24x7!


AT ONE TIME in living memory, there were no cellular phones. But one needs to remind

oneself occasionally that such was the case because at present these devices are as ubiquitous as they are. The world is infested with mobile phones and has been so for the last several years: The number of mobile phone subscriptions worldwide is reported to have reached a total of 6 billion in 2011—which means there is one for practically each human alive. But the proportion of all mankind connected to one mobile phone network or the other is only about 87 percent, but even this is quite a significant amount, when you come to think of it.

Martin Cooper has the distinction of having made the first call ever from a handheld mobile phone. He was the main researcher in the Motorola team that developed cellular phones that were small enough to be carried everywhere. On 3 April 1973, he made his historic call—to a counterpart in the rival Bell Labs—using a portable handset.

As I walked down the street while talking on the phone, sophisticated New Yorkers gaped at the sight of someone actually moving around while making a phone call. Remember that in 1973, there weren’t cordless telephones or cellular phones. I made numerous calls, including one where I crossed the street while talking to a New York radio reporter - probably one of the more dangerous things I have ever done in my life. - Martin Cooper, Motorola

Cooper’s call was a truly significant occasion, not so much because he could move as he talked but because the instrument he used was light enough to be toted about by a human. The first mobile telephones in the world had been installed in cars. Car ‘radiotelephone services’ were available in 1946 itself in the USA. With vacuum tubes and relays among the components, they tipped the scales at 40 kilograms. To justify their claim to being mobile, they had to be mounted on vehicles! The telephone that Cooper used

was no lightweight champion itself: it weighed 1 kilogram. It might be mentioned here that this invention was made available for a price just short of 4000 dollars.

Be that as it may, it was only six years later that the first commercial cellular network was launched, in Japan. In 1981, a network was established in Scandinavia. In 1983, a mobile phone system called DynaTAc was launched in the USA. And by the mid-1980s, several other countries got their first mobile telephones.

Inventor Charles E. Alden claimed, in the 29 April 1906 issue of the New York World, to have invented a device called the “vest pocket telephone” although Alden never had the chance to produce this device in large quantities.

Beginnings - I

Source: Wikipedia


The growth in the number of mobile phone users has been exponential ever since they were first introduced. It is hardly a wonder that the generations that were born in the early 1980s, now grown up, do not know what it was like to not have mobile phones. The word generation is used here sensu ‘a group of individuals born and living contemporaneously’, as defined by the Merriam-Webster dictionary.

Four generations (the term being used here as in ‘types or classes of objects usually developed from an earlier type’, to borrow from the lexicon again) of mobile phones have appeared since Martin Cooper first used a ‘brick’.

The capacities of the technologies are constantly improving, extending

the uses of the mobile phones far beyond voice calls. The new uses, such as games, and applications such as Whatsapp, account for the extraordinary popularity enjoyed by mobile phones. But it is evident that the most obvious reason for their popularity remains their being wire-free—which in turn allows the

user to wander according to his or her whim.

Given this, it comes as a surprise to many that mobile telephone networks cannot really be described as ‘wireless’. There are wire-free aspects—significantly at the customer end. And even recently

1G

In the beginning there was 1G, only it was not known as that at first. The DynaTAC phones of that generation, if they were any indication, had talk times of around half an hour. And they needed to be charged for 10 hours. As we have seen previously, they were heavy. In 1G, the voice of a user was modulated to a high frequency electric signal (as in radio). It was only after the arrival of 2G, the ‘second generation’, that the term ‘1G’

was made up.

2G

Second generation cellular phone technology was launched in 1991 in Finland. In 2G technology, the voice of a user is encoded to a digital signal. 2G systems make more efficient use of the available spectrum compared with 1G. Data services became available for mobile phones through 2G. The first text message (SMS) was sent in 1992 to a mobile phone in the UK from a computer. The next year, the first phone-to-phone SMS was sent, in Finland.

The third generation of mobile phone technology

was launched in Japan in 2001. Improvements came

fast and furious, with names such as 3.5G and 3G+ being

applied to the enhancements. What these meant for the user were higher data transfer speeds (200 kbit/second and more), facilitating mobile Internet access, video calls and mobile TV.

3G

It is hardly a wonder that the generations that were born in the early 1980s, now grown up, do not know what it was like to not have mobile phones.


Generations fourAfter close to a decade of 3G, the technology was showing signs of cracking under the demands of applications such as streaming media. New technologies that offered nothing less than a 10-fold increase in speed over 3G were required. WiMAX and LTE, developed by Sprint in the USA and TeliaSonera in Scandinavia, respectively, have been christened ‘4G’. IP telephony, cloud computing, gaming services, video conferencing and high-definition mobile TV are among the conceivable applications of 4G.

Technology is constantly changing. Given this, the identification of any radio network technology as belonging to a particular ‘generation’ is somewhat arbitrary particularly since there is no official definition of the label. Some developers of technology talk of a ‘generation’ being a ‘new, non-backward compatible technology’, a term that is as easy to understand vaguely as it is difficult to explain succinctly. Mobile users, on the other hand, expect a new generation to perform better and cheaper. This may not always be true—a new version of an older generation may be superior in performance to a newer generation. Hence it is more unambiguous to refer to a technology by its name, such as GSM, LTE and UMTS, and its version number.

Nevertheless, a certain enthusiasm to use ‘generation’ with respect to technology projects is detectable. Some research papers have talked of ‘5G’ in the context of as-yet undefined mobile communications standards. This enthusiasm for nomenclature even extends to the past: mobile radio telephony (pre-1980s), which preceded cellular telephony, has been referred to as ‘0G’.

4G

there has been a dependence on communications satellites for, say, facilitating telephone calls between Europe and North America. But increasingly, there are very solid structures providing the frameworks on which the networks run. To be more precise, there are physical systems of optical fibres in place. Optical cables stretch all over the world. They extend across continents and oceans.

Optical fibres are transparent fibres made of glass or plastic. Individual fibres are very thin, just microns thick. These fibres can be used in telecommunications because light can be sent through them, and this light may be made to carry information (that is to say, voice and video signals and computer data).

SINGULAR APPLICATION


[Alexander Graham] Bell and his assistant Charles Sumner Tainter jointly invented a wireless telephone, named a photophone, which allowed for the transmission of both sounds and normal human conversations on a beam of light. Both men later became full associates in the Volta Laboratory Association.

On June 21, 1880, Bell’s assistant transmitted a wireless voice telephone message a considerable distance, from the roof of the Franklin School in Washington, D.C., to Bell at the window of his laboratory, some 213 metres (700 ft) away, 19 years before the first voice radio transmissions.

Bell believed the photophone’s principles were his life’s “greatest achievement”, telling a reporter shortly before his death that the photophone was “the greatest invention [I have] ever made, greater than the telephone”. The photophone was a precursor to the fiber-optic communication systems which achieved popular worldwide usage in the 1980s. Its master patent was issued in December 1880, many decades before the photophone’s principles came into popular use.Source: Wikipedia

Beginnings -2

Light sent into one end of an optical fibre travels to the other end, bouncing off the sides because of the phenomenon of total internal reflection. The light cannot escape from the fibre anywhere else along its length if the refractive index of the material of the fibre is higher than that of the surrounding medium. To ensure total internal reflection and prevention of

leakage, a fibre is produced with a higher-refractive index core and a lower-index cladding.

It is very advantageous to use optical fibres in place of electrical wires. Optical fibres are much cheaper than the equivalent lengths of metal wire, to begin with. At the same time, they can carry more information than wires. Being much thinner, many fibres can be bunched together in one cable. Compared on a size basis, an optical fibre cable can carry more telephone lines (or cable TV channels) than a metallic wire. Given all this and the heavy traffic of information associated with 4G or even 3G, optic communication systems are the de facto backbone of mobile phone and other telecommunication systems and the Internet.

Light signals in one optical fibre do not interfere with those in another—unlike electric signals in wires: this results in clearer telephone conversations. Signal attenuation is less with optical fibres, which translates to savings in money to service providers and to users.

Optical fibre does not pick up environmental noise, something that cannot be claimed for electrical wires.Optical fibres can be used even where explosive or inflammable gases are present since they do not carry electricity. For the same reason, they can be used in high-voltage environments and in structures prone to lightning strikes.

Advantages Galore


A fibre optic data link has a transmitter at one end of a fibre and a receiver at the other end. (For ‘full duplex operation’, that is, for simultaneous transmission in both directions, another fibre, with another transmitter and receiver, is required.) Repeaters are provided to make up for losses in signal power over long hauls. Drops in signal strength can lead to a poor service. A repeater detects signal pulses and reshapes and retransmits them.

On land, optic fibre cables are commonly laid underground. They are passed through ducts from one junction box to another in lengths of 2 to 5 kilometres. The ducts are made of polyethylene. Multiple ducts are laid in parallel so that additional cables can be installed in the future. In India, the ends of these as-yet unused, colourful ducts protruding from the earth are a common sight.

Traditionally, optic fibre cables were pulled through the ducts using winch lines. Large pulling forces are required because of the friction between the cable and the internal duct wall.

Cables are now commonly installed in the ducts by jetting, an alternative to pulling. In this process, the cable is pushed into a duct. At the same time, compressed air is injected into the duct. The air flows at high speed, dragging he cable along. The

air nudges the cable loose if it lodges against the duct at any bend. In the process, large frictional forces are avoided. Friction is further reduced through the use of lubricants that have been developed specially for cable jetting.

The equipment required for cable jetting consists of a compressor and a feeder box. The cable is delivered to the feeder box by a pair of hydraulic rollers. The feeder box gathers the cable and the

Given the heavy traffic of information associated with 4G or even 3G, optic communication systems are the de facto backbone of mobile phone and other telecommunication systems and the Internet.



compressed air and directs them into the ducts. The pushing force provided by the rollers and feeder box increases the jetting distance considerably. Unlike cable pulling, equipment is needed only at one end of the duct.

Clearly, optical cables are more readily jetted than copper wires since they are lighter and more flexible. Optical cables have their advantages, but they are also sensitive to the physical properties of the compressed air. If the air temperature is more than 10 degrees Celsius above the ambient temperature, the optical properties of the fibres may not be preserved. In practice, because cables are usually laid in remote locations, portable diesel-powered compressors are required to supply the compressed air. Diesel-powered compressors typically deliver air at temperatures 40 to 50 degrees Celsius above ambient. So coolers must be used to bring down the temperature of the air before it enters the feeder box.

Further, moisture must not be allowed to condense from the compressed air on the cable. Moisture on the cable will lead to clumping and large pressure

drops, and the cable will not travel to the next junction box. The jetting process will then need to be interrupted to clean the cable and duct, thus increasing the time required for installation. Hence, a moisture separator is employed to dry the compressed air entering the feeder box.

Once the end of the cable reaches the next junction box, all the equipment moves there. The compressor needs to be a machine that can be moved easily, and it must deliver a pressure of 175 psi. The DT 400-175 CL, a 12 bar machine, is particularly suitable for cable laying applications.

The entire cable jetting operation is simultaneously reminiscent of both threading a needle and embroidery (particularly the running stitch), and it must be one of the most singular uses of compressed air and compressors.

n

The compressor needs to be a machine that can be moved easily, and it must deliver a pressure of 175 psi. The DT 400-175 CL, a 12 bar machine, is particularly suitable for cable laying applications.


ABOVE: Cable Jetting INSET: Compressed air powered cable blowing machine


You might think it curious to find that it is about helium, this verse,But consider all of entirety, the universe,

This element, helium, along with hydrogen, makes up percent ninety-eight,Of its entire mass (the layman tends to use the term weight),

Yes sir! A quarter of all the material in the cosmos, you see,Consists of this element, whose symbol is spelt H-e,

Do you not agree that it is time,We celebrated this plentiful element in rhyme?,

Long, long ago, there was nothing—something called a singularity,Then the Big Bang gave us heat, space, gravity,

On the Recovery of Helium

The ‘Big Bang Theory’ is the name given to the presently most accepted model that describes the early development of the universe. The Big Bang was an event that has been determined to have taken place around 13.798 billion years ago, give or take 0.037 billion years. In the words of Wikipedia, ‘the Universe was in an extremely hot and dense state and began expanding rapidly. After the initial expansion, the Universe cooled sufficiently to allow energy to be converted into various subatomic particles, including protons, neutrons, and electrons. Though simple atomic nuclei could have formed quickly, thousands of years were needed before the appearance of the first electrically neutral atoms. The first element produced was hydrogen, along with traces of helium and lithium. Giant clouds of these primordial elements later coalesced through gravity to form stars and galaxies, and the heavier elements were synthesized either within stars or during supernovae.’

In the Big Bang model, in the beginning (‘time t=0’), there was a ‘causal singularity’—all the dimensions of the universe were zero, its density was infinite, and its temperature was infinite.

The Big Bang

That’s where all this helium came from,It materialised along with a lot of hydrogen and a little lithium,

Strangely, it is not at all common on earth,Of it there is a dearth,

In fact it is quite rare,There is very little in the air,

It is no surprise therefore that helium was found first in the sun,The discoverer was an astronomer named Jules Janssen,

Studying an eclipse in India, to be specific, in Guntur,He used optical equipment of course, not a santoor,

J. Janssen, that fine fellow,He found in the solar spectrum a line of the brightest yellow,

HELIUM IS RARE


On the Recovery of Helium

Jules Janssen is a French astronomer. On 18 August 1868, there was a solar eclipse, and Janssen was in Guntur, studying it, where the eclipse was total. He detected a spectral line in sunlight, produced by a hitherto unknown element. An English astronomer, Norman Lockyer, observed the same line in the solar spectrum just two months later in Britain.

Because the line appeared near the lines designated by the German physicist Joseph von Fraunhofer as D1 and D2 (which are produced by sodium), Lockyer named it the D3 Fraunhofer line. But Lockyer proposed that the line was due to a new element that was had not been found on earth. Thus he had the privilege of naming this element. This he did, with the English chemist Edward Frankland.Janssen and Lockyer are jointly credited with detecting helium first.

Most of the helium in the world is believed to have been produced by the radioactive decay of uranium and thorium. Alpha particles, emitted during such decays, consist of the nucleus of helium atoms. The radiogenic helium accumulates in natural gas and in minerals such as cleveite, which is a uranium ore. Natural gas may contain helium in concentrations as high as 7 percent by volume.

Helium in natural gas

The stability and low energy level of the helium atom’s electron cloud account for the chemical inertness of the element. They also account for the lack of interaction among helium atoms.

Helium is inert

When helium is cooled to temperatures near absolute zero, its viscosity almost entirely disappears. This phenomenon is known as superfluidity.

At normal temperatures, unlike other gases, helium heats up when it is allowed to expand freely: it is said to have a negative Joule-Thomson coefficient. Only when helium is pre-cooled below its Joule-Thomson inversion temperature (around 40 K at 1 atmosphere pressure) does it cool on expansion.

Liquid helium can exist in a state called helium II, which exhibits unusual characteristics. One of these is the creeping effect. Helium II escapes from unsealed vessels by moving along the surface against gravity. It moves in a 30 nanometre thick film, evaporating when it reaches a warmer surface. It is very difficult to confine liquid helium.

Strange properties

Produced by an element mysterious,They named it after the sun, the Greek word for it being helios,

In our planet helium is produced by the decay of elements radioactive,It is rather furtive,

It tends to gather in minerals and deposits of natural gas,From where scientists isolated it, determined its atomic mass,

It is non-toxic and it has no colour, odour or taste,It is a waste,

Of time trying to make it react with anything,It is noble and inert and of a disposition shrinking,

But it is a record holder,For in the liquid state there is nothing colder,

Its boiling and melting points are the lowest,Look you in the north, south, east or west,


It was used once in balloons and airships,And as a protective atmosphere, it is this gas that the arc welder worships,

The liquid form is used in making rocket fuel,And in keeping the superconducting magnets of MRI scanners cool,

There is a great demand for this stuff,But the production is just not enough,

It involves fractional distillation and low-temperature gas liquefaction,The helium obtained is then of a purity that affords satisfaction,

Helium escapes readily from any application-it is easily leaked,So it must be conserved, eked,

Recover, compress, re-liquefy,Re-use each molecule 30 times or 35,

Compressors used to pressurise helium must be extremely gas-tight,Its valves and components must meet higher quality standards, be just right,

The compressor must be cooled well (very),Such must a compressor be that is used in helium recovery, n

About a quarter of all the helium that is produced is used in cooling superconducting magnets. MRI scanners are the main commercial application of helium.

Industrially, helium is used as a pressurizing and purge gas.Helium is also used in processes used to make silicon wafers.

Helium has a very small atomic diameter, and hence its diffusibility is very high. Helium can pass through the smallest openings and pores. This leads to losses of helium from a system in which it is used.

Helium is Sneaky

Liquefying helium involves (1) a precooling step involving a mechanical expansion machine, a turbine, and (2) gas decompression and countercurrent cooling. It is technically difficult to liquefy helium. The liquid helium is transported in containers to individual users.

The liquefaction process is also expensive and requires a large amount of energy.

Recovering the helium gas that evaporates or is exhausted from equipment is another important operation in a helium plant. The collected helium is transported by a network of pipes to a central gas balloon. When the balloon fills up, high pressure gas compressors are started automatically. They discharge helium at up to 300 bar into high pressure containers, which feed the helium liquefaction plant.

The WP4341, WP156L, WP276L, WP316L, WP4330 and WP4351 are among the compressors available from Elgi Sauer for helium recovery and compression. The working pressure of these machines is in the range from 3 bar to 200 bar. The leak rate of the compressors is as low as 0.1 millibar per litre per second. Helium recycling modules (used in heat treatment of metals) fitted with these compressors feature a gas recycling capability of 99 percent. Elgi Sauer compressors can deliver up to 270 cubic metres per hour.

Elgi Sauer Helium Compressors

Applications


ATS ELGI now supplies a sophisticated crash repair system, the Model 106, in

collaboration with Spanesi, the Italian manufacturer of hydraulic lifts, welding machines and other automobile-related equipment. The Model 106 is a straightening bench provided with a universal jig.

Damaged vehicles weighing up to 5 tons can be repaired using the Model 106. The straightening bench is available in two lengths: 4 metres and 5 metres. Every car model available in the market can be repaired, including models without a pinchweld construction.

A damaged vehicle is secured on bench using the universal jig. The vehicle is anchored at the most resistant structural points for straightening. The Model 106 has five sliding crossbars on which the vehicle is secured. Jigs or clamps are fastened to the vehicle. This can be done very quickly.

Measurements are obtained through the jigs themselves, eliminating the

time required for this operation. Drawings and critical dimensions of more than 2000 car models are loaded in a storage system known as Winstar. The drawings are displayed conveniently for easy reference.

The pulling column of the Model 106 can exert a straightening force of up to 10 tons, in any direction. Car repairers can carry out repairs very simply and rapidly using the Model 106.

The Model 106 comes with a jig trolley that houses an entire complement of bushes, heads, clamps and extensions that may be required for various vehicles. All these parts are clearly numbered. Wrenches used with the pulling bench are stored in a rear panel of the jig trolley. A cover is provided to protect the various accessories from dust. The trolley is provided with castor wheels, and so it can be moved readily.

Here is a demonstration of how the system is used to repair a vehicle damaged in a crash. n

The ATS ELGISpanesi Model 106

HOW ITWORKS


First the repairer assesses the damage to the vehicle. Then the parts of the body that need to be replaced are removed. Then the crash repair system is used. When pulling is to be carried out, the first step is to mount the damaged car on the crash repair system.

With the jigs in place and holding the structure at the critical points, the vehicle is ready for repair.

Measurements are obtained through the jigs themselves, eliminating the time required for this operation. Drawings and critical dimensions of more than 2000 car models are loaded in a storage system known as Winstar.

Those parts of the structure that cannot be repaired and must be replaced are cut and removed.

The pulling column exerts the required force on the vehicle through a chain


Cutting and removal of other damaged structural parts is carried out.

Cutting and removal of other damaged structural parts is carried out.

Measurements are carried out to ensure that all critical dimensions are restored. Upholstery, accessories and any other parts of the vehicle that have been removed must be re-assembled next.

After painting and polishing, the vehicle is as good as new and ready for delivery.

The pulling column of the Model 106 can exert a straightening force of up to 10 tons, in any direction. Car repairers can carry out repairs very simply and rapidly using the Model 106.

SPANESI MODEL 106


ad


Elgi Compressors are powering the next revolution as fossil fuels gradually give way to viable alternatives like bio-diesel, bioethanol and bio-gas

A Spin in the Country


IMAGINE that you are on an outing in the country. You drive along a busy highway

first. Then you turn off into a quiet, winding country road. On either side of the road, there are fields. Here and there, there are trees. As you drive, you note that there is a capricious wind. It is ruffling the crops like a mischievous schoolboy tousling the hair of an unsuspecting friend. You draw to a halt to enjoy the scene better.

The silence that envelops you is, as the expression goes, deafening. But no, it is not entirely quiet; you can hear the wind catching the trees in gusts. And hark, isn’t that the melodious whistle of some invisible bird calling from close by? You can even hear water flowing somewhere—why, there is a brook running by the side of the road! And a cow is lowing in the distance. You draw in a deep breath, and you note with great satisfaction that the air is rich with the healthy smell of ripening grain. A beautiful setting, is it not?

The only problem is that with the present state of affairs, you may not be able to take such rides in the

not-very-distant future. Why? The reason lies in your dependence, as a typical human being of the early twenty-first century, on certain fuels to power your vehicle. Practically all the cars, scooters and motorbikes (and for that matter, lorries, ships and aircraft) today run on petrol, diesel, LPG, CNG and the like—all derived from fossil fuels.

Fossil fuels include coal, oil (also known as petroleum) and natural gas. They are found locked away underground and below the sea bed. They have been formed from buried dead organisms subjected to high temperatures and pressures through natural processes. The world reserves of fossil fuels have taken millions of years to come into existence. In other words, the formation of fossil fuels is extremely slow.

On the other hand, the fossil fuel reserves are being exploited rapidly. By one estimate, the consumption of fossil fuels is so great that it results in the production of some 21 billion tonnes of carbon dioxide each year. Here are the daily production (which is to say, consumption)

A Dependence on Fossil FuelsIn recent years, the world has been relying very heavily—to an extent of 86.4 percent—on fossil fuels for its energy requirements. Petroleum contributes 36 percent; coal, 27.4%; natural gas, 23.0%.

Non-fossil sources of energy include nuclear and hydroelectric sources, which meet 8.5 percent and 6.3 percent of the requirements, respectively.

What about other sources of energy, such as solar energy, geothermal energy, tidal energy and wind energy? All of them put together amount to no more than 0.9 percent of the world’s energy production.


rates of fossil fuels as they were in 2006:

Natural gas 2,963billion cm3

Oil 13.4 million cm3

Coal 16.8metric tonnes

Bear in mind that consumption was rising then at a rate of more than 2 percent per year.

Since these figures are prodigious, it is only natural to wonder just how much natural gas, or oil or coal, there is in the ground. It is not possible to answer this question with great precision. Seven years back, the levels of proved resources were understood to stand at 905 billion metric tonnes of coal, 177.9 cubic kilometres of oil and 180 trillion cubic metres of gas. It must be mentioned that there are also some estimates that are more optimistic.

In any event, the reserves of oil, gas and coal are finite and will be depleted in due course. Given current production rates and proved reserves, and assuming that production can be maintained at a constant level each year and that all proved resources can be

recovered; here is how long each resource will last:

Natural gas 61 to 167 yearsOil 43 yearsCoal 148 to 417 years

In reality, it will not be technically possible or economically feasible to continue production for these periods. And these numbers can be affected significantly by changes in prices, technology and so forth.

It is perfectly understandable if you feel a trifle meditative, even melancholy, as you ponder over these matters. The term energy crisis becomes more than just a term encountered in journalistic and other writings. The attractions of the idyllic situation to which you have driven may actually cease to hold your attention.

But there is hope yet. The world is not drifting irresistibly towards a world unburdened with oil and gas. There is a worldwide interest in renewable energy and even a tentative movement towards generating renewable energy in significant quantities. And the solution—or at least part of the solution—to the energy

It is perfectly understandable if you feel a trifle meditative, even melancholy, as you ponder over these matters. The term energy crisis becomes more than just a term encountered in journalistic and other writings.


crisis is all around you, in the rural settings to which you have driven.

As we are aware, there are a host of systems that have been contemplated, developed or used in the quest to change to renewable energy: solar photovoltaic systems, solar flat plate collectors, solar thermal power systems, ocean thermal energy conversion systems, wave energy systems, tidal power systems, windmills, geothermal energy systems. And as we have noted previously, the success with these has been modest.

Somewhat less known, but nonetheless promising, are biofuels. These are fuels obtained through biological means, by fixing carbon from the atmosphere. Biofuels are in the form of solid biomass, liquids or gases.

One biofuel that is already being used widely is bioethanol. This is essentially ethanol, an alcohol, mostly made using carbohydrates from crops cultivated for sugar. It is also produced from cellulose, derived from plant material. Bioethanol can be used in its pure form to drive vehicles. However, it is more commonly used as a fuel additive to improve the octane number and vehicle emissions. Oil price hikes have served to focus attention on this biofuel, and it is used widely in Brazil and in the USA.

Another biofuel that can be used in its pure form but is mostly being used as an additive is biodiesel. This fuel is made from vegetable oils and animal fats using a process of transesterification. Added to diesel, it reduces the levels of pollutants in the exhaust. Biodiesel is being used commonly in Europe.

It is mandatory in many countries now to blend biofuels with ‘regular’ fuel. Together, bioethanol and biodiesel provide 2.7 percent of the world’s fuels for road transport. The International Energy Agency has set a goal of meeting a quarter of the world’s transportation requirements through the use of biofuels by 2050.

The Biodiesel Cycle

Bioethanol Production

A SPIN IN THE COUNTRY


A third, highly promising, biofuel is biogas. This consists of methane produced from organic material by digestion using microbes. Biogas can be produced from a variety of materials, including waste products. For example, wastewater sludge and municipal solid waste can be used to produce biogas. Biogas is produced in relatively simple systems known as anaerobic digesters, and a solid byproduct, called the digestate, is produced. This byproduct can be used as a biofuel itself. Alternatively, it may be used as a fertilizer.

One of the attractions of biogas is that it can be produced from agricultural byproducts and waste. Soiled bedding from cattle sheds, unconsumed crop residues, fallen leaves, farmyard manure and weeds, all of which are available abundantly in farms, can be used to produce biogas. Hence, practically every farm is a potential producer of energy.

However, methane is a gas under normal conditions, and so it is difficult to transport from the source. It is

more readily conveyed from one place to another when it is highly compressed. And here is one application where compressors have a role to play in generating and using renewable energy.

Many medium-sized biogas plants have been set up in Gujarat with financial support from India’s Ministry of New and Renewable Energy (MNRE) and the state government. One of these plants was has been installed at Baroda in a residential complex. At this plant, there are six biogas digesters. This plant has six digesters. The biogas is stored in two huge balloons before it is processed.

The gas is pressurised by a screw compressor and fed into a scrubbing unit which removes contaminants. The pressure of the pure biogas is raised to 250 bar in multiple stages using Elgi Sauer reciprocating compressors. This pressurised gas, now referred to as CNG (‘compressed natural gas’), is stored in bottles.

How does the miscellaneous input that goes into a biogas unit become methane, a colourless, odourless, energy-rich gas? What all the raw material has in common is that it is made up of compounds with large organic molecules. There are four stages involved in the conversion of these complex molecules into the simple ones of methane (each of which has just five atoms—one atom of carbon and four of hydrogen): (1) hydrolysis, (2) acidogenesis, (3) acetogenesis and (4) methanogenesis. Bacteria are critical in every stage of the biogas production process.

The methane-producing reactions are carried out in a vessel known as a digester. The reactions are anaerobic*—they take place in the absence of oxygen—and so the digester must be sealed to prevent the entry of air. This measure also ensures that there is no discharge of smelly intermediate products into the surroundings.Before the digester is sealed, it may have to be ‘seeded’, or inoculated, with bacteria. Usually this is achieved by adding cattle slurry or previously processed material.

The period over methane is produced from a certain amount of ‘raw material’ depends on the type of bacteria present in the digester and on the ambient temperature. The process is very slow at low temperatures, but even in tropical conditions, methane production proceeds over a period of many days.Biogas production can be carried out at different scales, to meet domestic or industrial requirements. *Methane can also be produced aerobically.

Biogas production


A ton of waste (cow dung and grass waste) yields 40 cubic metres of bio-CNG at the Baroda plant. The power consumption of the plant’s compressors is 6.8 kilowatts. Half of the gas produced is used to provide street illumination in the community. The rest is available for retailing to industrial applications and for local transportation needs.

It is easy to imagine the changes that could be brought about if such biogas plants are put up everywhere. Biogas would be widely available at economic rates, and households would use it for cooking. The gas might be used for street lighting.

And you might be driving in the country in a bio-CNG-powered vehicle!

n

Biogas Compressors

n Since the gas is inflammable, no leakage is permissible. The compressors must be gas-tight.

n The motors and valves used with gas compressors need to be flame-proof.

n Pistons and cylinders need to be made of special-grade material.

A ton of waste (cow dung and grass waste) yields 40 cubic metres of bio-CNG at the Baroda plant. The power consumption of the plant’s compressors is 6.8 kilowatts.

A SPIN IN THE COUNTRY


StrangeCombinations


StrangeCombinations

BEVERAGES! They are hard to miss. They are ranged on shelves in supermarkets and in crates outside roadside shops. They are packed in colourful containers designed to catch the

eye. They are available in cans, cartons and bottles of plastic and glass. Usually sweet, almost invariably coloured, often carbonated, they also frequently contain fruit juice. Apart from water, they may contain a sweetener, colouring, preservatives and flavouring agents. They commonly have oraange, lemonade, grape and cola flavours. They are frequently displayed in refrigerators with transparent doors and illuminated interiors so that they are available chilled at the point of sale. And there are some that can be consumed warm. In all their forms, these drinks promise you that they are tasty and that they will quench your thirst.

The business of selling beverages has become highly developed, but it had simple beginnings: it began with the marketing of lemon juice. Apparently, there was a company that sold the drink to thirsty people in Paris in the 17th century. The drink was sweetened with honey, and it was sold in cups. It was sold through vendors who wandered about in the streets, carrying it in tanks. No doubt the idea of selling other fruit juices in the same manner arose soon enough.

After about a century of this, there was a revolution of sorts in the early beverage industry. Joseph Priestley, the multifaceted Englishman who is credited with the

discovery of oxygen, invented a method of producing carbonated water. He treated chalk with sulfuric acid (then referred to as oil of vitriol) to generate carbon dioxide. He dissolved the gas in a bowl of water. Priestley found that this treated water had a pleasant taste and resembled naturally available carbonated mineral waters. He offered it to friends as a refreshing drink. Refinements of Priestley’s apparatus were made by others, and then it became feasible to produce carbonated water in large quantities. Soon, juices, spices and other flavours were added to the carbonated water.

The sodas became so popular that pharmacies with soda fountains were established as a part of American culture


There was a doubling in the consumption of sweetened beverages in the USA over 25 years at the end of the 20th century. Over the same period, the prevalence of obesity in the population too doubled.

In the USA, artificial mineral waters, also known as soda water, quickly became popular, and the soda fountain was born. There were successful businesses just fabricating soda fountains in large factories in the 1830s. One of the popular flavouring agents in the late 19th and early 20th centuries in the USA was phosphoric acid. A drink called phosphate soda was made by adding it to fruit syrup and carbonated water. It was available in pharmacies, where it was served with ice. Other substances added as flavours included dandelion and sarsaparilla. The sodas became so popular that pharmacies with soda fountains were established as a part of American culture.

Just as various drinks evolved, so too did the manner in which they were dispensed change. In 19th century America, these beverages were consumed at the phar macy itself. At this time, soda water was available in bottled form in England. Soda and other drinks began to be bottle extensively in the early 20th century. Inventors came up with many methods to keep the carbon dioxide from escaping from the water. Hundreds of patents were filed in the USA for bottle tops, caps, lids and corks. The invention of the ‘crown cork bottle seal’, the first truly successful means of keeping the bubbles in the water, is attributed to one William Painter of Maryland, who patented it in 1892.

In 1899, a glass blowing machine that could be used to produce bottles automatically was invented. This device allowed production of bottles (previously hand blown) to increase greatly.

Cartons made of cardboard were invented in the 1920s. Soft drink vending machines appeared in the same period. And later in the 20th century, aluminium cans came to be used. A significant quantity of beverages is sold in cans even today.

But as the consumption of these drinks grew in the 20th century, evidence was gathering that

people were having more of it than was good for them. Numerous research studies were finding that there seemed to be links between increased consumption of soft drinks and health problems. The main culprit seemed to be the sweeteners added to the drinks. There was a doubling in the consumption of sweetened beverages in the USA over 25 years at the end of the 20th century. Over the same period, the prevalence of obesity in the population too doubled. It is not quite clear whether it is the drinks themselves that have led to an increase in the number of overweight people. Their role may have actually been indirect. For instance, one study found that people consume more calories at their meals on days when they have sugar-sweetened beverages. Another study found this to be true of even saccharine-sweetened (‘no-calories’ drinks. The subject is somewhat contentious, but evidence has been presented to support the claim that sugar-sweetened drinks are linked with diabetes, tooth decay and nutritional problems. And according to critics, the ingredients


of soft drinks, such as caffeine and sodium benzoate, may cause anxiety, sleep disruption, DNA damage and hyperactivity when consumed in excess.

The list of health problems that have been attributed to excessive consumption of various soft drinks is long and disturbing: metabolic syndrome, elevated blood pressure, bone loss, low potassium levels… It has been suggested that drinking ‘soda’ reduces milk consumption and the benefits that the nutrients it contains. Cola-type drinks contain phosphorus, which it has been suggested, may displace calcium bones, leading to osteoporosis. The controversy revolving around these suggestions may have tempered people’s consumption of beverages.

Limits are prescribed for even the quantity of fruit juices that may be consumed. Paediatricians recommend that infants below six months of age not be given juices at all. Children aged 1 to 6 years should not have more than six ounces (roughly three-quarters of a cup) every day. It has been pointed out that many fruit juices contain more sugar than sweetened soft drinks. And it has been argued that

commercial fruit juices are highly processed and lack fibre, as a result of which they do not confer the health benefits of fresh fruit.

Nevertheless, juices are typically rich in various substances needed for good health: potassium, antioxidants, folic acid, vitamin C. Juices have been reported to improve blood lipid profiles, improve digestion and prevent bladder infections. Drinking fruit juices has been reported to protect against stroke, delay the onset of Alzheimer’s disease and reduce the risk of many cancers. In moderate amounts, juices can help provide the nutrients that fruits contain. With these perceptions, the consumption of fruit juices, particularly in the Western world, has increased in recent years. The consumption of juices at breakfast is very popular.

Juices are produced by pressing or macerating fruits or vegetables. Juice that is filled immediately into cartons or bottles is referred to as ‘direct juice’. More often, juices are subjected to one or more processes such as filtration, canning, pasteurization, freezing, concentrating and spray-drying.

juices are typically rich in various substances needed for good health: potassium, antioxidants, folic acid, vitamin C.

STRANGE COMBINATIONS


Machines used for filling, labeling, packing and stacking are among those that need compressed air. The filling machines are considered aseptic areas, and oil-free compressed air is used in them.

Pasteurization is a process that slows the spoilage of food caused by microbes. In this process, a food isheated to a specific temperature for a specified period of time, after which it is cooled very rapidly. This reduces the number of viable disease-causing pathogens.

Canned foods normally have a shelf life of one to five years. But some canned products may remain perfectly edible after 30 years.

Spray-drying is a process in which a liquid or slurry is rapidly converted to a dry power by drying with a heated gas.

PROCESSES USED IN JUICE PRODUCTION

Generally, a juice is concentrated after pasteurization by removing most of the water. This makes it easier to store and transport the juice. To create the actual drinks, water and sugar added to the concentrate along with secret ingredients at the plants. This is when strange combinations such as ‘cranberry-kiwi fruit’ and apple-pear are born. The mixture is heated to 80 degrees Celsius and stirred in large containers.

The stirring is performed using automatic agitators. These are powered by h e a t - r e s i s t a n t stainless steel air vane motors. The air motors are driven by compressed air. The motors have a simple, light-weight construction. They work over a wide speed range, the energy of the compressed air being converted to the kinetic energy of the rotor. The rotors have a number of vanes mounted in slots and rotate eccentrically in cylinders. The vanes are pushed outwards by the centrifugal force and mix the juice thoroughly. By the time the mixture reaches the packing stations, it is sterile.

STRANGE COMBINATIONS

Oil-free compressed air is used for this application.

Compressors are also used to different extents in the operation of most of the equipment in a beverage production factory. Pneumatic valves and pneumatic

devices are all operated by compressed air. Machines used for filling, labeling, packing and stacking are among those that need compressed air. The filling machines are considered aseptic areas, and oil-free compressed air is used in them. n



One of Its Kindcompressed air in nature

“Strange as it may seem, we understand the distribution of matter in the interior of the sun far better than we understand the interior of the earth.”

-Richard Feynman

Beyond reachCountless school children have now learnt that the Earth has a layered construction, rather like an onion. An image of our globe sliced to display the layers is imprinted in our minds. In this image, our planet looks like a giant fruit—it has a thin skin (the crust), flesh (the mantle) and, at the centre, a seed (the core).

This knowledge of the Earth’s structure has developed only over the last 100 years or so. Previously, what we knew about the Earth’s interior came only from the observations of miners. Mines in general do not extend deeper than a few hundred metres (a handful—just a handful—of mines are more than 3000 metres deep). And considering the dimensions of the world (the distance from the surface of the Earth to its centre is more than 6300 kilometres), that is not much. So we really did not know much more than the fact that after digging through soil for some distance, we would encounter rock.

In the first decade of the 20th century, scientists observed that shock waves from earthquakes

were bouncing off from certain depths in the Earth as though there was some obstruction there. They had discovered the boundary between the crust and the mantle and the one between the mantle and the core. The next advance came some 20 years later, again from studying seismographic records of earthquakes: it was discovered that the core of the Earth itself had two layers—there was an inner core and an outer core.

But there was only so much that even seismic studies could reveal, and little more was learnt over the next 25 years. In 1961, American scientists began an attempt to drill through the ocean floor to obtain samples of the Earth’s mantle. Their idea was to understand the interaction of rocks so that earthquakes could be predicted. The offshore oil industry was coming into existence just then, and using equipment developed for offshore drilling, the scientists drilled a set of holes in the sea bed off the coast of Mexico. The water was 3600 metres deep there, and the holes were around 180 metres deep. Attempts to go further were


unsuccessful although the project continued for five more years before it was terminated.

In 1970, Russian scientists began drilling on land, in the Kola Peninsula. Their aim was to drill to a depth of 15 kilometres. Twenty years later, having drilled deeper than 12 kilometres, they had to stop. The scientists decided that drilling any deeper was not feasible, and their project too ended. Even so, their efforts had led them to a number of interesting findings. They found that the temperature of the rocks at 12 kilometres’ depth was 180 degrees Celsius, not 100 degrees Celsius as they had anticipated. They had expected that basalt rock would replace granite at a depth of 7 kilometres. They found no basalt, but there was a different form of granite at that depth. Surprisingly, there was water in the rocks there, and the mud from that level was rich in hydrogen. It is true that the Kola hole had gone deep, but it had not punctured even a third of the Earth’s crust.

If you are keen on studying material from the mantle, you could examine kimberlite pipes. These are vertical structures in the crust. It is believed that kimberlite pipes have been created by explosions in the mantle (at depths greater than 150 kilometres) that have sent molten rock to the surface at very high speeds. They contain crystals of olivine and minerals such as peridotite. Sometimes kimberlite pipes contain diamonds, and it is for this that they are best known. But on the whole, we continue to be dependent on indirect methods

to study the interior. It is worth reiterating here that our knowledge of the earth’s interior remains limited.

Lively EarthIn the 20th century, it came to be appreciated that the earth’s crust is a livelier place than one would imagine. Continents move! The matching outlines of continents (such as the eastern edge of South America and the western edge of Africa) suggested this. And there was some support for the notion that vast landmasses move—from the geographical distribution of some living things. But the idea of continental drift did not become popular until the 1960s, when unquestionable evidence was found that showed that the ocean floors, as well as the continents,

were moving. And very soon, almost everyone accepted that the entire crust of the Earth was divided into interconnected segments that constantly pushed each other.

The segments came to be called plates, and the study of their movements acquired the name ‘plate tectonics’. It is understood now that there are some 30 plates on the Earth’s crust, all moving at different speeds and in different directions. The movements are too slow to be detected without sensitive equipment. Nevertheless, the plates push against each other, and at each of the ‘convergent boundaries’, one plate moves under the other, sinking into the mantle. The process is called subduction and happens at a rate of a few centimetres per year.

“But on the whole, we continue to be dependent on indirect methods to study the interior. It is worth reiterating here that our knowledge of the earth’s interior remains limited.”


0 to 40 (but very variable!) Crust (with an abundance of silicates)40 to 400 Upper mantle (mainly peridotite to a depth of 150 km)400 to 650 Transition zone650 to 2700 Lower mantle2700 to 2890 D layer2890 to 5150 Outer core5150 to 6370 Inner core

Whereas the crust of the Earth is rich in silicates, there must be heavier material elsewhere to account for its total mass. It is also evident that there is a belt of liquid metal at some depth that explains the Earth’s magnetic field. But beyond this, very little can be stated with confidence. The inner core is probably solid because the pressure near the centre is too high for any rock to be in any other state. The core may be as hot as 7000 degrees Celsius, which happens to be roughly equal to the temperature of the sun’s surface.

The Structure ofThe Earth

Depth (kilometres) Layer

In the words of the author Bill Bryson, ‘As we sit here, continents are adrift, like leaves on a pond… It is only the brevity of lifetimes that keeps us from appreciating the changes. Look at a globe and what you are seeing really is a snapshot of the continents as they have been for just one-tenth of 1 per cent of the Earth’s history’.

It turns out that just as the crust is bustling with the lateral movements of the plates, there are movements in the mantle too. And in the mantle, there are vertical movements as well. This too was an idea that took a long time to be accepted. But by around 1970 again, geophysicists understood that rocks in the

ONE OF A KIND


mantle are fluid enough to move about. In hotter spots the rocks rise, whereas on cooling they sink. The resultant mixing, taking place hundreds of kilometres below the surface, is referred to as convection. There is a strong resemblance between convection in the mantle and the circulatory movements that take place when a fluid is warmed, but the former is an extremely slow process.

Even so, it was clear that there was a lot of activity even in the interior of the Earth. This was most surprising. As writer Shawna Vogel expressed it, ‘It was as if scientists had spent decades figuring out the layers of the Earth’s atmosphere—troposphere, stratosphere and so forth—and then had suddenly found out about wind.’

Gas propulsionThe insights we have gained in the past few decades might suggest that we have a deep (for want of a better word) understanding of the workings of the Earth’s layers. The truth is that all our knowledge does not allow us to predict with any accuracy when the Earth’s internal activity will express itself at the surface next—in the form of earthquakes and volcanoes.

Subduction zones are prone to earthquakes and volcanic activity. Long chains of volcanoes exist along these zones in what are known as volcanic arcs. But when will the next eruption will take place? That we cannot say. Why? And how does an eruption take place?

A subducting layer travelling into the mantle grows increasingly

hot. This produces changes in the material, and at some point (between 50 and 150 kilometres below the surface), much of the water that it contains is driven off. The water rises into the overlying mantle, and this is believed to reduce the pressure in the mantle rock and thereby promote its melting (‘hydrous melting’)—the rock becomes magma. Since a rock is not made of a single pure material (like water) but is a complex mixture of a number of kinds of molecules, it does not have a clear-cut melting point. When it is heated, it begins to soften at a certain temperature (depending on the composition and pressure) and progressively becomes more molten as its temperature increases. Eventually, at some point it is entirely molten.

Subduction zones are prone to earthquakes and volcanic activity. Long chains of volcanoes exist along these zones in what are known as volcanic arcs. But when will the next eruption will take place? That we cannot say.


what emerges from the volcano depends on the compressed gas generated by this extraordinary machine—a machine so extraordinary, in fact, that there is only one of its kind.

The magma is less dense than the surrounding rock and thus it rises. To begin with, it oozes through pores. At some depth, it gathers and becomes ‘flow’ in the sense that we associate with the word at the surface. If the magma reaches a point where the rocks above are less dense and those below more dense, it will stop rising and form a magma chamber, where it my stay for long periods (decades to millennia). Ultimately it may rise to the surface, possibly erupting explosively there. There may be eruptions even on the way up, caused by magma coming in contact with water-saturated rocks. The steam explosions may carve out conduits for the magma to pass through to the surface. As may be imagined, there are practical difficulties that prevent the conditions deep under the ground from being studied. This is why it is impossible to state when exactly a volcano will erupt.

During its travel from the mantle to the crust the magma experiences changes in the conditions, mainly pressure and temperature.

Among the several gases contained in magma are sulfur dioxide, steam, carbon dioxide, hydrogen, hydrogen chloride, hydrogen fluoride, hydrogen sulfide and carbon monoxide—derived from the crust, mantle, seawater and air. At the high pressures deep below the Earth’s surface, these gases are dissolved in the molten rock, just as carbon dioxide is dissolved in soda water. As the magma rises towards the surface, the pressure decreases, and the gases come out of the solution (as when a soda bottle is opened) as bubbles. But the pressure is still very high: At a depth of 2 kilometres, the pressure is 500 bar. It is 1000 bar at 3.8 kilometres, and it is 2000 bar at a depth of 7.4 kilometres. Thus the Earth’s mantle-and-crust system routinely produces compressed

gases at extremely high pressures—pressures that human technology will be greatly challenged to produce—it is surely the most extraordinary gas compressor.

To continue the story of the rising magma: the bubbles in the magma increase the volume occupied by it and reduce its density. The number and size of bubbles may increase, producing a magma foam. The magma may then proceed quicker on its upward journey. Often magmas begin crystallizing well before an eruption. There is little time for the crystals to grow, and they may be only millimetres in size. Sometimes they grow much larger. As crystallization continues, the dissolved gases are displaced progressively.

On reaching the surface, relieved of the pressure, the gases expand enormously. They may expand to occupy around 700 times the volume of the magma (lava temperatures are commonly in the range from 700 to 1250 degrees Celsius). There may be explosions during an eruption, powered by the gaseous expansion, scattering the lava as fragments of rock (known as tephra). Or the lava may emerge relatively quietly as a flow.

Depending on the exact conditions, a particular magma may give vastly different eruption products. It may form light, air-filled pumice, or it may produce razor-sharp obsidian, which is like glass. The volcano may even produce both these products at the same time. And what emerges depends on the compressed gas generated by this extraordinary machine—a machine so extraordinary, in fact, that there is only one of its kind.

n

ONE OF A KIND


BR Hills with a Difference

The BR Hills get their name from Bilikal, meaning white rock, and Ranganatha, to whom the famous temple in these hills is dedicated.

Origin of the name Biligirirangan


ONCE I was in conversation (having a ‘ragchew’) over the radio with a ham radio

operator. His occupation was coffee planting, and he told me that his ‘QTH’—ham jargon for location—was the BR Hills. My idea of these hills was very vague then. I only knew that they were situated somewhere in southern Karnataka.

I found out that BR was short for the rather more exotic sounding Biligirirangan. It turned out that the BR Hills were, along with the Nilgiris, located at the only region where the Western and Eastern ghats meet. From another perspective, the BR Hills and Nilgiris are the point from where the two mountain ranges radiate along their respective directions.

The Western Ghats and the Eastern Ghats are rather different in character. The former are considerably higher. The Western Ghats are also famous as one of 18 ‘biodiversity hotspots’ recognised in the world. They are home to many species of bird, mammal, reptile, plant and so forth that are found nowhere else in the world (‘endemics’). The Eastern Ghats too are impressive in their proportions. But they are somewhat enigmatic, having been studied less compared with their western counterpart. The flora and fauna of the two mountain ranges have distinct characteristics, and so it is of great interest to know what plants and animals are found at the BR Hills, where they meet.


But I found little else by way of published information about these hills. And practically no one I knew had actually been to them, save for the casual amateur radio acquaintance, who happened to live there.

Then I came across the writings of one Randolph Camroux Morris, a British planter. R.C. Morris lived in the Biligirirangan Hills in the first half of the twentieth century. His address read ‘Honametti Estate, Attikan P.O., via Mysore, S. India’. Honametti was one of four estates that had been planted by Morris’ father, also named Randolph Morris, and his family. The senior Morris, who hailed from Scotland, had created the first of his estates in the 1880s. He was described as adventurous and pioneering. According to the ornithologist Salim Ali, he had planted in ‘the midst of virgin evergreen forest, miles away from civilization and without roads or communications of any sort’. The only humans in the vicinity were members of the Sholaga community. Apparently the country was ‘stiff with truculent elephants who were often vehemently resentful of the unwelcome human encroachment on their pristine domains’.

R.C. Morris was born in 1894 in the first coffee estate his father planted. The next year, Morris (the pater), was injured seriously by a gaur during a hunting trip. He continued to live in the hills, developing his estates, until 1918. That year, he was gored to death by a wild boar on another hunting expedition.

After an education at England, Morris junior returned to India to support his father with the planting business. R.C. Morris was a sportsman-naturalist, or shikari-naturalist, a kind of person from a past age who revelled in hunting and simultaneously maintained a keen interest in studying the forest and the living things in it. For about three decades, beginning from the 1920s, Morris wrote regularly in the Journal of the

Apparently the country was ‘stiff with truculent elephants who were often vehemently resentful of the unwelcome human encroachment on their pristine domains’.


Bombay Natural History Society. Other naturalists and hunters were thrilled reading Morris’ descriptions of his encounters with tigers, gaur and elephants as well as his observations on the habits of the creatures of the forest. They learnt that the Biligirirangan Hills were a part of the country that had a plenitude and diversity of wildlife. So I was not alone in learning about the BR Hills through Morris’ notes—the entire world had been introduced to the place by them a half century earlier. A number of Morris’ friends were guests at Honnametti and went on hikes into

the surrounding forests to hunt or photograph the wild animals.

Living in an age when hunting was perfectly acceptable, Morris shot many animals. But Morris was among the earliest naturalists to recognise the alarming rate at which wildlife was being lost in India, particularly after the First World War. As the years went by, he restricted himself to killing ‘rogue’ elephants, cattle-lifting tigers and older and diseased animals. Through his writings, he formed an educated public opinion about the need to conserve wildlife. It was thanks to the efforts of persons such as R.C. Morris that Lord Willingdon, the Viceroy, called for the All-India Conference for the Preservation of Wildlife in 1935. This led to the Indian Board for Wildlife being created after Independence. The BR Hills themselves, with their rich wildlife, were declared a sanctuary, and eventually their status was elevated to that of a ‘tiger reserve’.

The BR Hills are a popular destination of ‘eco-tourists’ now. A small number of tents and cottages at K-Gudi, managed by a state-run resort and the forest department, represent the main accommodation available to the visitor interested in wildlife. Safaris are conducted along designated trails in the mornings and evenings.

You may see practically every large mammal of the hills on one of these

rides, including what must be the unofficial ‘big five’ of south India: the gaur, tiger, leopard, elephant and sloth bear. I saw the last two on one safari. Of course, you can also see the more mild-natured spotted deer, sambar, wild boar, barking deer and giant squirrel. Actually, the BR Hills hold so much wildlife that there is a definite likelihood of encountering animals even on the drive to K-Gudi from the plains and vice versa. In the immediate environs of the accommodation at K-Gudi itself, there is a good diversity of forest birds.

I saw there, in a brief spell of very casual ‘birding’, the bronzed drongo (a bird that gets its name from the gloss of its feathers, visible particularly in bright light), the white-bellied drongo (again the name is descriptive), the gold-fronted chloropsis (which has green plumage and is therefore known as a leaf bird), the jungle babbler, the scarlet minivet, the pygmy woodpecker, the paradise flycatcher and other birds.

BR HILLS WITH A DIFFERENCE

ABOVE: An aerial view of BR HillsLEFT DOWN: RC MorrisRIGHT (Clockwise): Drongo, Jungle Babbler. Scarlet minivet


You can even see large wild animals at K-Gudi itself. There were wild boars wandering around the resort when I went there, and I saw a spotted deer passing right through it, displaying no alarm whatsoever at the presence of a number of humans, all being as noisy as humans generally are.

When I visited the BR Hills the first time, one of the camp elephants at K-Gudi, a cow, had been attacked recently by a wild tusker. The wild elephant had literally punctured the side of the poor cow elephant. Luckily, veterinarians attended to the animal and saved its life. The cow elephant had a great big bandage about its middle, looking like a gigantic gift tied up in ribbon. It cannot have been much fun for it to have been at the receiving end of a raging bull elephant’s wrath. Imagine being in her place.

Tourists get to see only one aspect of the BR Hills—the moist deciduous forests around K-Gudi. But there is much more to these hills. For example, there are grasslands in

the higher elevations and there is scrub at the foothills.

I had a rare chance to visit areas of the BR Hills that are not open to the public when I received an invitation to participate in a bird survey there. The survey was organised by the Director of the park, Mr. Vijay Mohan Raj, with the assistance of Dr. Subramanya, the well known birdwatcher. A number of birdwatchers had been invited from various parts of India to participate in the survey. We assembled at K-Gudi, where we were grouped into teams and allotted camps.

My camp was at a place named Gundal. We reached Gundal after a long drive. The sun was setting as we reached the staff quarters there. The hills were framed in red, and we could hear the occasional bird calling before it turned in for the day. The nocturnal shift was taking over, as was evident from other calls, such as those of a pair of spotted owlets. Then a nightjar gave voice. It sounded uncannily

like a ball bouncing on a hard surface—the notes were spaced widely at first and progressively grew closer until you could scarcely distinguish the ‘bounces’.

Before going to bed ourselves, we sat in the dark, looking at the night sky. It was clear, and the stars were bright. It grew cold rapidly, and a wind sprang up, making it quite chill. And a near-full moon rose. For a while it highlighted the silhouette of a bare tree in front of us. The sight was most pleasing, and I shot a few photographs of it.

It was clear, and the stars were bright. It grew cold rapidly, and a wind sprang up, making it quite chill. And a near-full moon rose.


The next morning, we set off early along our first transect, or sample area. As we walked, we noted down the birds we encountered. We came to a small reservoir encircled by low hills. This reservoir contained the waters of the Gundal river, after which our camp was named. The transect went along the edge of the water. So as we walked, we had a hill slope on one side and the water below us on the other. As a result, our list had a mix of water birds and scrubland birds: for instance, we recorded the whiteheaded babbler, Indian robin and grey junglefowl from the scrub side, and from the other side we noted the median egret, common sandpiper and brahminy kite.

Presently the track veered away from the reservoir. There were more trees in the vegetation now. We saw sambar on the trail a couple of times. At the end of the transect, we found a pleasant place to rest in. This was on top of a steep bank above the Gundal river. We had our lunch at this spot. Even as we ate, we observed birds coming to the water to have a drink or to bathe. First came a male koel, all shiny black and red-eyed. He simply sat in the shallow part of the stream, allowing the water to flow around him. Then came a female paradise flycatcher, russet and white, with a black crest. She dropped into the water from a branch overhanging the stream and flew back to the branch. She repeated this several

First came a male koel, all shiny black and red-eyed. He simply sat in the shallow part of the stream, allowing the water to flow around him.


TOP: Reservoir on the Gundal RiverABOVE (From left): Indian Robin, White headed Babbler, Paradise Flycatcher


times. Her performance was copied by a blacknaped blue monarch, another flycatcher, who was next.We set off for the return count in the afternoon. Basavaiah, our ‘watcher’, pointed out a pair of elephants on the slope of ahead of us. They were very far away. It was truly incredible how Basavaiah could spot them with his unaided eyes. We had difficulty in seeing them even with our binoculars.

Interestingly, the bird species that we saw in the afternoon were not quite the same as those that had been evident in the morning. As a result, our list grew quickly. We saw a particularly goodnumber of raptors, or birds of prey,

including one short-toed snake eagle, which flew down low above us. Suddenly a drongo, much smaller than it, started pursuing it. At one point the drongo actually sat on the eagle’s back in mid-air!

The next day’s transact took us up to a ridge and then down. The path was very rugged, covered with stones and small rocks. We needed to watch where we were stepping to avoid tripping. We had left the reservoir behind, and we saw no water birds this day. We did come to the course of a stream, but it was nearly dry. At one point the rocks held a tiny pool of water. There was disproportionate bird activity

Our ‘watcher’, pointed out a pair of elephants on the slope of ahead of us. They were very far away. It was truly incredible how Basavaiah could spot them with his unaided eyes.


there, highlighting the importance of water for life.

Although we were focused on spotting birds, we could not avoid noting that there was much butterfly activity along the transect. In fact, the day belonged to the butterflies. There was a drying water hole at one point close to the ridge, and it held dark mud, which was the colour of chocolate cake. Butterflies were swarming there. They settled on the mud, drawing moisture from the wet soil. Butterflies do this regularly, and the habit is called mud puddling. It is believed to give them important minerals.

That night, we took stock of our tally of birds. We were very satisfied. We had, over the two days of the survey,

recorded more than a hundred species. Several of these were additions to the BR Hills checklist compiled by Dr. Subramanya. Some of them were uncommon species, including the white-bellied minivet, greater spotted eagle and osprey.

The sky above us was crowded with extraordinarily bright stars that last night. You could practically hear the stars jostling each other. You do not see such sparkling skies in cities and towns nowadays, thanks to city lights, dust and smoke. Such skies belong to a different age, when the earth was cleaner on the whole. They belong now only to places such as the BR Hills. n

They settled on the mud, drawing moisture from the wet soil. Butterflies do this regularly, and the habit is called mud puddling.



Engineering

SolutionsNew products from ELGI, ATS-ELGI and ELGI Sauer

Elgi’s EN series of encapsulated compressors is presently available in the power range from 2.2 to 30 kilowatts. These compressors use the same world-class technology employed in Elgi’s large industrial-grade compressors. They feature proprietary airends, after-coolers and electronic controllers.

The EN series integrates the major systems of a compressor such as the air intake system, compression system and discharge system into one robust, encapsulated system. The air filter, air intake valve, solenoid valve, air-oil separator tank, oil separator element, oil filter, safety valve, oil sight glass, minimum pressure valve, oil drain valve, thermostatic valve and blow down valve are all integrated with the encapsulated airend. This simplified design results in a leak-free, silent and energy saving system. By integrating all major systems, and using fewer parts, the design is simplified, and connections that are potentially sources of leakage and pressure loss are eliminated. The compact integrated platform is also designed to run cool and efficient: all EN series models, including the smallest ones, are equipped with after-coolers.

Regular maintenance is faster and easier with an encapsulated airend because the components are integrated. Thus the down-time of the compressor is reduced. There are few consumables, and so the compressor has a lower life cycle cost. The user of the compressor has faster returns.

Big Things in Small Packages


Elgi has launched a new model in the Global Series electric-powered portable screw compressor range – The E22 Trolley. The model is powered by 22 kW motor delivering FAD of 131 cfm at 7 bar working pressure. These Global Series compressors play a vital role in demanding applications like construction, mining, and abrasive blasting where electric power is available and in work environments where quiet and emission-free operation is required. Larger airends, high-efficiency motors, cleaner air, less pollution and low pressure losses are all hallmarks of Elgi’s Global Series compressors. These factors maximize energy efficiency and minimize operating costs

E22 Trolley features airend with Elgi’s unique energy-efficient eta-V profile. Compressors using this profile runs slower and with higher efficiency. The slower running speeds reduce the stress on components and raise the efficiency of the compressor. This improves energy-efficiency, reduces maintenance costs and saves money.

E22 portables are mounted on a 2 wheel trolley which are rugged and highly manoeuvrable. The machine can function at ambient temperatures from 50C to 450C and even in dusty environments. A high-performance pre-filter wire mesh is provided in the canopy. This arrests dust before it enters the compressor. The compressors are provided with parking brakes. They are designed with a closed base-frame bottom to hold oil-spills and to avoid dust entering the compressor.

All instrument controls and monitoring systems are grouped together on the control panel. Operators can check the operational status through a combination of easy-to-use instruments and indications on the panel. The indications also displays warning and shutdown messages if abnormal conditions are detected.

E22 Trolley Mounted


Screw compressors are popular on account of their high efficiency and, thus, lower power consumption. The energy efficiency of a compressor can be improved in two ways: (1) compressing in two stages and (2) using a single stage airend of a larger size.

In two-stage compression using an oil-flooded compressor, the performance depends mainly on the maintenance of an optimum inter-stage pressure. Two-stage compressors are very sensitive to ambient conditions. Whereas an energy benefit of 14 percent can theoretically be enjoyed with such machines, the actual benefit is only 8 to 9 percent.

With a single-stage compressor of a larger size and an optimized clearance design, the adiabatic efficiency and volumetric efficiency are both higher. Single-stage machines are very effective even when the ambient conditions are variable. If the pressure ratio is only moderately high, a larger single-stage airend is a good option in overcoming the limitations of two-stage compressors.

Elgi has developed the Axis 310 airend to realize the advantages of a larger-size single-stage compressor. The Axis 310 features an internally developed rotor profile. The performance of this airend is 5 percent better than that of an equivalent two-stage compressor. The package length is also significantly less.

Axis 310 Airend

There are several applications like ash handling, pipe line cleaning Breweries, Chemical(Organic aerobic digestion), Sewage & water treatment (Aeration), Glass Blowing (mould cooling) and textile applications looking for low pressure compressors operating at less than 4 bar. Current design of industrial compressors will have limitations in working at such low pressure due to limitations on bearing load and life, lubrication and reliability.

However some manufacturers offering oil injected compressors with external lubrication to meet low pressure requirements. This will have some compromises on efficiency and reliability. Single stage oil free compressors will meet this requirement without any compromises on efficiency and reliability.

Elgi has developed series of industrial oil free compressors for high pressure applications in the last 6 years. The technology is now extended to develop low pressure single stage oil free compressors to meet the above requirements. This will ensure efficient, reliable and low maintenance solution for such application requirements.

Water-Cooled Low Pressure Oil-Free Screw Air Compressors


Airlube UT Synthetic Fluid has been specially developed for use in oil-flooded rotary screw compressors. This fluid has been formulated using premium-grade polyalphaolefin (PAO), a synthetic hydrocarbon, and additives to ensure that the rotary components in screw compressors are well lubricated.Airlube UT Synthetic Fluid is designed for both high- and low-temperature operation and provides protection against wear. The life and efficiency of the compressor are improved.Benefits• Thermal stability• Low volatility• Reduced varnishing and deposits• Improved fire safety• Low maintenance and operation costs• Extended oil-change intervals

Airlube UT Synthetic Fluid

Elgi, with decades of experience with all the requirements of compressed air in the railways, has developed oil-free compressors for electric locomotives. The model RR14100 OF compressor and its accessories are used to power conventional locomotive braking systems. This model has an operating pressure of 10 kg/cm2 and has a free air delivery of up to 1200 LPM. The model RR20100 OF is designed for use in the braking systems of three-phase locomotives and has an operating pressure of 10 kg/cm2, with a free air delivery of 2000 lpm.

The entire process of design and development was carried out in-house using the DFSS (Design for Six Sigma) method. Three compressors were validated through 400 hours of continuous running in the performance verification test. Chittaranajan Locomotive Works, Indian Railways, has placed development orders for these oil-free air compressors for both conventional and three-phase locomotives. This indigenization has helped Indian Railways reduce costs and deliver on time. It has also helped save valuable foreign exchange.

Oil-Free Air Compressors for Electric Locomotives

ENGINEERING SOLUTIONS


In addition to standard solutions, Elgi Sauer provides products designed to meet more specific and complex requirements of customers. These include gas-tight or explosion-proof designs, units featuring gas engines and mobile, container-type units.

Elgi Sauer compressors housed in containers and mounted on mobile units are used in the construction and operation of oil and gas supply lines. Elgi Sauer containers are also used in a variety of offshore applications in oil and gas production. These are compact, self-contained units with diesel engines. These ‘containers’ offer a number of advantages:

• These are portable solutions for both short-term and long-term requirements.• They are suitable for existing businesses with space restrictions.• They ease operating overheads.• They have a long operating life, and there is a guaranteed availability of

replacement parts—for a minimum of 30 years.• Elgi Sauer customer services, beginning from the initial enquiry, extend over the

entire life of the product.

ELGI SAUER

Elgi Sauer Containers: Solutions for All Applications


Elgi Sauer supplies air compressor packages to various domestic and international projects executed by BHEL. In hydro power stations, these packages supply compressed air to the oil pressure unit of the turbine-governing system and to the main inlet valve in the main power house.

Elgi Sauer has developed a package for installation at Varzob, in Tajikistan. The package features two high-pressure WP66L compressors coupled directly to a motor. The most significant aspect of the requirements was that the compressor would be subjected to extreme ambient conditions. The temperature will range from -20°C to +45°C.

Elgi Sauer developed a canopy-and-heater arrangement specifically for this application. The blocks of the compressors alone were imported from Germany, and customization was carried out in-house in India. Complex heat load calculations were involved. A sound-proof enclosure, or canopy, was developed in which the compressors would operate smoothly in the sub-zero conditions.

ATS Elgi’s newly launched under-chassis washer (UCW) is designed to wash any passenger car or SUV up to 4900 mm long. The washer blasts off grease, grime and dirt from the under-chassis. The UCW has a galvanized iron construction and uses an 18 LPM, 55 bar discharge of water.

Features of the UCW:

• High cleaning efficiency (due to high pressure of water jet, produced by a positive displacement pump)

• Space requirements are limited• Only two nozzles are needed because they can rotate

360° and are mounted on a movable carriage. As a result, the maintenance requirements are low.

• Very low water consumption—just 36 litres or so for a car (excluding the wheel arches and engine compartment)

• Automatic sensing of the length of a car—manual adjustments eliminated, makes washing easy

• Time required to wash a car: 120 seconds• Integrates with ATS Elgi’s Auto Car Washer

ATS ELGI

Under-Chassis Washer

Powerful Solutions for BHEL Hydro Power Station

ENGINEERING SOLUTIONS


The ML4030 (capacity 30 tons) is one of the most technically advanced hydraulic heavy vehicle lifts. It is designed for use in heavy duty vehicle assembly and repair shops. The MLW030 may be used for assembly, maintenance, washing and servicing and for changing oil.

Features:• Four individually controlled mobile columns• Splash-proof power supply unit, with a 10 metre long connection cable for powering the entire lift. The

main switch of the power unit is directly connected to each column of the system.• Lifting carriage with fixed wheel engaging forks• Electronic synchronisation and safety monitoring comply with all applicable standards.• Smooth up-down lifting cycle, even with unequally distributed loads• Easy emergency lowering function for use in the event of a power failure• Dual safety: (1) Continuous hydraulic safety device featuring a check valve. (2) Mechanical safety device with

self-inhibiting safety hook• Automatic stop in the event of any problem, with error code displayed.

ATS Elgi’s Heavy-Duty Mobile Column Lift 030

THE ELGI MAGAZINE 1

Documents

Transcript of THE ELGI MAGAZINE 1