Appliaction of Cryogenics

TECHUNIQUE’08 A

NATIONAL LEVEL

TECHNICAL PAPER PRESENTAION

ON

Modern applications in cryogenics

ABSTRACT

Cryogenic Engineering involves design and development of system and

components, which produce, maintain and utilize low temperatures.

Cryogenics finds its advanced applications in the fields like space, medical,

manufacturing etc. To consider the field of cryogenics as that involving temperatures

below -1500C (123K).

Cryogenic engineering utilizes properties of gases like nitrogen, oxygen,

argon, neon, fluorine, methane, and helium .In various applications like cryo-treatment of

automobile parts to improve there life and efficiency, deep cryogenic tempering of metals

and alloys, cryo treatments of gun barrel, for cutting tools, domestic food processing

tools, for sporting tools, copper conductors, aerospace comp ,landing gears, supports,

medical/dental applications ,surgical tools equipments, musical instruments, cryo treated

materials like steels, titanium ,plastics, copper, nylon, aluminum brass, glass.

This paper explains about advance applications & new technology of

cryogenics which are used in new technical world.

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INDEX

SR.NO. CONTENTS PAGE NO.

1). INTRODUCTION 03

2) PROPERTIES OF CRYOGENICS FLUED 04

3) APPLICATION OF CRYOGENICS 05

4) WORKING PRINCIPAL 08

5) HOW SAFE THE SYSTEM 09

6) CASE STUDY 10

7) FUTUR SCOPE OF CRYOGENICS 12

8) CONCLUSION 14

9) REFERENCESS 15

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INTRODUCTION

What is cryogenics?

The word “cryogenics” is derived from two Latin words.

Cryo - means cold Genics - means science.

Cryogenics is “the science of cold”. It suggests that how to get low temperatures and how

materials behave at the low temperatures. It includes unusual and unexpected material

property variations appearing at low temperatures.Cryogenics may be considered as the

recent advancement in the field of refrigeration. The temperature below –150c (123k) are

considered as cryogenic temperature. The cryogenic temp are those boiling point are

below –150 c (123K).The four gases which mainly contribute for cryogenic application

and research are O2 (B.P.90K), N2 (B.P.77K), Helium (B.P.4.2k) & H2 (B.P.20K).

Cryogenic is a stage where gases of air turns liquid, steel becomes brittle as glass and

properties of materials changes, also some significant effects appears such as vanishing

of specific heats, superconductivity and ductile – brittle transitions in C-steel.

Cryogenics originally referred to technology and art of producing low

temperatures. Cryogenics can be defined as the study of ex-tremble low-temperature

branch of physics that studies the causes, effect and utilization of extremely low

temperatures.

At cryogenics temperatures many material behave in unfamiliar manner than

when at ambient temperatures some materials retain the changes at cryo, temperatures to

ambient temperatures. Mercury solidifies while glass, rubber & some metallic materials

becomes brittle. The specific heat decreases at low temperatures the electric resistance of

many metals and alloys becomes very low abruptly. Cryogenics studies evolve around

behavior and properties of materials at below 00c which may be as low as -20000c. It is a

broad area of science covering a large spectrum from testing at, metal treatment, and

thermal imaging industrial gases and liquid for cryotreatment, applied cryo processes to

equipments and measuring instruments used for cryo temperatures generation and

monitoring.

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PROPERTIES OF CRYOGENIC FLUIDS

Nitrogen: Liquid nitrogen is a clear colorless fluid that resembles water in appearance.

At standard atmospheric pressure liquid nitrogen boils at 77.36K and freezes at 63.2K

saturated liquid at 1 atm has a density of 307Kg/m3.At the normal boiling point, liquid

nitrogen has heat of vaporization of 199.3KJ/Kg. It is produced commercially by

distillation of air.

Argon: Liquid argon is clear, colorless fluid with properties similar to liquid nitrogen. It

is inert and non toxic. At 1 atm pressure liquid argon boils at 87.3K and freezes at 83.8K

saturated liquid argon has density 1394Kg/m3. It is obtained by adding a small auxiliary

argon recovery column in air separation plant.

Neon: Liquid neon is a clear, colorless liquid that boils at 1 atm at 27.09K and freezes at

24.54K. Neon is inert, has a large heat of vaporization per unit volume and has a higher

density which makes it an attractive refrigerant when compare to hydrogen.

Hydrogen: Liquid hydrogen has a normal boiling point of 20.3K and a density at a

normal boiling point of only 70.79Kg/m3. Liquid hydrogen is an odorless, colorless

liquid that alone will not support combustion. In combination with oxygen or air,

however hydrogen is quite flammable.

Liquid CO2: It has a boiling point of -78.40C with a practical cooling limit of -550C to -

650C due to low efficiency and dry ice accumulation near the lower limit. LCO2 has the

advantage over L-N2 in that it is typically slightly less expensive per pound and has a

slightly better cooling capacity per pound at typical temp. Main problem of CO2 is dry ice

formation and accumulation will be apparent at -450C, copious at -550C & may be

problematic at lower temperatures.

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APPLICATIONS OF CRYOGENICS.

1. In Space Research: In rocket & missile launching system cryogenic fluids

such as L-O2 & L-H2 use as propellants. To provide & handle this cryogenic fluid

cryogenic cooling is used.

2. In Electronics: Sensitive microwave amplifiers, called masers, are cooled to L-

N2 or L-He temperatures so that thermal vibrations of the atoms of the amplifier element

do not seriously interfere with absorption & emission of microwave energy.

Cryogenically cooled masers have been used in missile detectors, in radio astronomy &

in space communication system.

3. In Biological & Medical applications: L-N2 cooled containers are used to

preserve whole blood, tissue, bone marrow & animal semen for long periods of time.

Cryogenic surgery has been used for the treatment of Parkinson’s disease, eye surgery.

4. In Food Processing: Today frozen foods are prepared by placing cartons on a

conveyor belt & moving the belt through a L-N2 bath. The cryogenic process requires

about 7 min. compared with 30 to 48 min. required by conventional methods.

5. In Manufacturing Process: Cryogenic cooling is used to cool the tool tip at

the time of machining. It increases the tool life. Oxygen is used to perform several

important functions in the steel manufacturing process.

6. Recycling of Materials: By freezing the automobile or truck tire in L-N2 , the

rubber is made brittle & can be crushed into small particles. These particles can be used

again for other items.

7. In Metallurgy: To convert the retained austenite into marten site.

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WORKING PRINCIPAL

1. RECYCLING OF MATERIALS

One of the more difficult item’s to recycle is the automobile or truck tire. For

solving this problem the “CRYOGRINDING” machines are used.

The basic principle used in cryogrinding is that, the scrap rubber is cooled below

its embitterment temperature and pulverizes it in hammer mill. Rubber is cooled by using

liquid nitrogen. With this process we get about 90-95% recovery of rubber.

Cryogrindings offers the following advantages:-

Reduces the waste disposal problems

Reduces the requirements of fresh rubber

We can grind the smaller rubber particles down to 200 microns

Improved surface morphology

2. Polar Snow, a state-of-the-art technology for the production

of 'real snow'

Identical to natural snow but produced using liquid nitrogen, Polar Snow can be

mass produced at any required quality, from perfect powder for skiing or snowboarding,

to icy slush for tyre testing. Polar Snow has been used on the indoor and out-of-season

ski slopes all year round and for events such as the ISF World Pro Snowboarding Tour.

We have even developed a facility for testing tyres in snow for the automotive industry.

Polar Snow technology allows real snow to be made anywhere and anytime, from the

heat of the Sahara Desert to the dampness of London Parks. Give your event the

individual touch, and control the climate with Polar snow.

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3. For aerospace and launch vehicle application.

The NASA Glenn Research Center (GRC) has led the nations’ effort in the

development of production and handling technology of densified cryogenic propellant

systems for aerospace and launch vehicle application. The technology of subcooling

cryogenic propellants below their normal boiling point and thereby making the fluid

denser is one of the key process technologies necessary to meet the challenge of single-

stage-to-orbit (SSTO) and reusable launch vehicles (RLV). Densified propellants are

critical to lowering payload to orbit costs cause they enable more cryogenic propellant to

be packed into a given unit volume, thereby improving the performance of a launch

vehicle by reducing its overall size and weight. Density improvements of 8% for LH2

and 10% for LO2 are expected to reduce the gross lift-off weight of a launch vehicle

system by

Up to 20 percent.

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4. IN EMISSION CONTROLE SYSTEM

Effective emission control is essential for the pharmaceutical processing industry,

which relies on the use of its products. Ever since the introduction of the introduction of

the EU solvent emissions Directive, adopted in the UK in 2002, such processors have

been seeking ways to reduce their solvent consumption and enhance on-site emission

control, while maintaining efficiency.

The use of cryogenic technology in emissions is nothing new. Ever since the late

1980’s, cryogenic condensation systems have been used by chemical and pharmaceutical

manufacturers to freeze and recover solvent emissions. Such systems work by cooling the

exhaust gas stream-containing the solvent – to below the solvent’s own freezing point.

Liquid nitrogen, which has a temperature of -1960C, provides the cooling power to

literally freeze out the solvent, which can be recovered separately. The clean gas stream

can be released safely into the atmosphere.

High performance cryogenic condensation systems are capable of recovering solvents

in a pure form, which is suitable for re-use on site. The recovered solvent could

potentially be sold back to suppliers or to other manufacturers – so driving efficiency and

contributing to an overall reduction in the plant’s solvent use. In some circumstances,

further sustainability benefits are possible by recovering the liquid nitrogen used in the

freezing process it can be re-used elsewhere on site to ensure an inert processes

environment & reduce running costs.

To date these sustainability benefits have not been fully realized & they present an

opportunity for forward looking processing plants in the future.

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How safe is this system?

Common cryogenic coolants do not harm the Ozone layer, are not flammable, and

are not poisonous. The common coolants, Carbon Dioxide and Nitrogen, are normal

components of our breathable air. In fact, about 78% of our atmosphere is Nitrogen, so its

safety is pretty well demonstrated. Carbon Dioxide is the fizzy part of soft drinks, so it

better safe.

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5.CRYOGENIC BLAST CLEANING WITH CO2 PELLETS:-

Conventional blast cleaning technologies with sand, glass beads, other solids or

even water under high pressure leave behind abrasive residues and dirt. This results in

high cost for the disposal or processing of the contaminated abrasive materials.

Cryogenics blast cleaning with co2 pellets was therefore, developed as a new

process for industrial cleaning. The use of dry ice granulates is environmentally

compatible, economical and preserves the material being cleaned. The process can be

affected directly at the production site, reduces down time and does not leave behind

abrasive residues.

The life of the cleaned objects, e.g. core boxes or dies, is considerably

extended. The use of these type of technology permits on site cleaning and even cleaning

during operation, thereby avoiding downtimes, as well as time consuming assembly work

which means an increase in productivity. Since the process operates without water the

often considerable drying cost associated with conventional blast cleaning methods are

avoided

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CASE STUDY

The space cryogenics Chinese efforts in space technology started in

late 1950s. Development continued steadily since the launching of the first

satellite in 1971. Commercial launching of foreign communication satellites

began in 1990 with H2/O2-engined rocket. Manned spacecraft programmer is

beginning. National communication satellites have been placed in orbit since

1984. Meteorological satellites

and resource surveying satellites with infrared imaging are also in service.

Cryogenic technology specific for the rockets and the spacecrafts has been largely

developed under.

FUTURE OF CRYOGENICS

Though a lot of work and research has been done in the field of cryogenics a lot,

more is needed to be done. The inherent disadvantage of cryogenic process is the heavy

cost which needs to be incurred in the equipment and the costs of the process itself.

Future use of superconductivity system is proposed for high speed rail transport. If

research in this field is successful it will be revolutionize the land transport systems.

Another field where cryogenics can play a vital role is that of automobile field. With the

increasing cost of hydrocarbons and the possibility that their reserves may soon be

exhausted hydrogen presence an excellent alternative from all consideration including the

fact that it does not produce any pollution on combustion.

If hydrogen becomes the fuel of the future it will have to be store in the liquid

state thus giving cryogenics an undreamed future. Also the application in medicine and

biology will have far reaching effects on the society. The use of artificial insemination in

cattle is made possible by cryogenics which is beyond doubt a boon to the villagers in our

country helping them become stronger socially and economically. A similar technology

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Modern applications in cryogenicsto freeze the human sperms and able to thaw it successfully after maintaining it in the

frozen condition for many years is possible with cryogenics.

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CONCLUSION

The current developments in missiles and propulsion systems are the direct

consequences of man’s foray into cryogenics.

Thus going application wise the field cryogenics is giving more promises for the

future than any other fields. And also the use of liquid hydrogen has put back the

importance of fuels such as petrol and diesel.

Thus it can be concluded that, the widely spread application of cryogenics in the

field such as; “Manufacturing technology, space technology, biomedical and chemical

applications Mechanical design” have pushed the man on the innovative track.

Hence finally it can be concluded that cryogenic form the main thrust of most

vital sophisticated systems in use, by countries whose hunger for technological

superiority is a never-ending desire.

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REFERENCES

1. IIM METAL NEWS VOL.5 FEB. O2

2. IIM METAL NEWS VOL. 2 JUNE. 99

3. IIM METAL NEWS VOL.6 APR. 03

4. Randall Barron

“Cryogenics Systems”

McGraw-Hill Book Company 1965.

5. Dr. V. D. Kodgire, “Material Science and Metallurgy for Engineers”, 1994,

pp.436-441.

6. http://www.cryogenicsindia.com/

7. http://www.metal-wear.com

8. http://www.polarsnow.com/

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http://www.polarsnow.com/

http://www.metal-wear.com/

http://www.cryogenicsindia.com/

Appliaction of Cryogenics

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