Cold suuply chain

23
Cold Chains: The Essential Infrastructur prof. Gautam Pherwani With the modernization of the nation’s infrastructure, cold chains are an essential part of the nation’s economy. Purvin Patel reports. A cold chain is a temperature controlled supply chain which is used to extend and ensure the shelf life of products such as fresh agricultural produce, seafood, frozen food, chemicals and pharmaceutical drugs. The cold chain consists of two logistic systems: Surface storage: Refrigerated warehouses for storage of temperature sensitive products. Refrigerated Transportation: Reefer trucks, containers, ships and trains for transport of temperature sensitive products. A cold chain logistics player could either be a cold storage owner or the owner of a fleet of reefer trucks. Also, there are 3PL firms which own the entire network, right from procurement to the final destination of the temperature sensitive products.

description

 

Transcript of Cold suuply chain

Page 1: Cold suuply chain

Cold Chains: The Essential Infrastructur prof. Gautam Pherwani

With the modernization of the nation’s infrastructure, cold chains are an essential part of the nation’s economy. Purvin Patel reports.

A cold chain is a temperature controlled supply chain which is used to extend and ensure the shelf life of products such as fresh agricultural produce, seafood, frozen food, chemicals and pharmaceutical drugs.

The cold chain consists of two logistic systems:

Surface storage: Refrigerated warehouses for storage of temperature sensitive products.Refrigerated Transportation: Reefer trucks, containers, ships and trains for transport of temperature sensitive products.

A cold chain logistics player could either be a cold storage owner or the owner of a fleet of reefer trucks. Also, there are 3PL firms which own the entire network, right from procurement to the final destination of the temperature sensitive products.Thus, the success of cold chain companies relies on how efficiently they can transport temperature sensitive products from the place of origin to their destination with full integrity. Different products require different temperatures. The common standard temperatures are Chiller (-2oC), Frozen (-18oC) and Deep Frozen (-25oC).

Current State Of Sector

Page 2: Cold suuply chain

Industries which need cold chains are fruits and vegetables, ice cream, processed meat and poultry, seafood, preventive medicines (mainly vaccines) and chemicals.

The cold chain has a critical role to play in India as two-thirds of the country’s population is dependent on agriculture for its livelihood. The Indian food market is estimated at over $182 billions. India is the second largest producer of fruits and vegetables in the world, with an annual vegetable produce of around 85 million tonne and an annual fruit produce of around 45 million tonne. Of the close to 130 million tonnes of fruits and vegetables that the country produces, nearly 40 percent gets wasted.

India is the largest producer of milk in the world, producing close to 100 million tonne, and accounting for nearly 17 percent of global production. About 35 percent of this milk is processed. More than 10 percent of annual milk production in the country is lost due to inadequate storage facilities.

India has roughly 5,300 cold storages with a capacity of 23 million metric tonne, over 90 percent of which are suitable just for storing potatoes only.

Inconsistent standards in different sections of the cold chain could lead to damage of food, either by shock or by undue temperature variations. This degrades food quality due to chemical reactions which are triggered off, which can otherwise be mitigated by low temperatures. To maintain integrity of food and pharmaceutical products, these providers rely on efficient and fully integrated end-to-end cold supply chain technology. Thus cold chain companies should design a supply chain solution which maintains the required temperature according to the physical attributes of the product.

Challenges In The Sector

Cold chains face several roadblocks in their growth and some of the most challenging hurdles are listed below:

Rising Real Estate Cost: A fully integrated cold storage facility of international standards, with one million cubic ft. of storage space, will require an area of approximately an acre, which is a huge investment.

Location for Cold Storage: Cooling units are not mobile units, so the location of such units becomes a key constraint as there are very few parcels of large land spaces available in India.

Lack of Proper Infrastructure: The cold chain industry in India is very fragmented, with players not having the strength to invest in the technology needed to build high quality cold storage or to invest in reefer trucks.

High Energy Cost: Energy expenses alone account for about 30 percent of the total expenses of the cold chain sector in India. This is the main constraint about setting up cold chains in India. India’s peak power deficit is around 17-18 percent. Thus the investment in back-up systems increases capital investment costs.

Page 3: Cold suuply chain

Uneven Distribution of Capacity: The majority of cold storages in India have been established in states like Uttar Pradesh, Uttarakhand, Maharashtra, Gujarat, Punjab and West Bengal. But the establishment of such cold storages needs to be more geographically diverse.

The cold storages present in India can cater to single commodities only. Different commodities require different temperature conditions, resulting in poor capacity utilization and low financial viability.

FDI Restrictions in Retail: Cold chain infrastructure needs huge investment. Easing restrictions on FDI in multi-brand retail could open up channels for further fund infusion from new foreign entrants.

Role Of Cold Chain Service Providers

With the demand for better quality food at affordable prices by consumers, companies rely on cold chain service providers to fulfill it. The service providers should be able to develop systems and processes to mitigate risk associated with temperature abuse in cold chains and thus help in business growth.

The service provider should understand the importance of capacity utilization, productivity, inventory, cost, waste, error and theft (WET) management, along with the ability to track and trace these parameters. This will help to reduce total system costs which in turn will improve the bottom line.

The success of implementing cold chain solutions to serve the consumers involves proper network optimization of warehouses, facility planning, the monitoring of product quality throughout the cold chain and having a corrective action plan to counter any gaps.Further, the higher cost associated with operating cold chains needs excellent operational efficiencies and continuous improvements to maximize profits for service providers.Other major challenges which make cold chains more complex are inadequate logistics infrastructure, poor road connectivity, inadequate IT systems and inefficient transport providers.

Product Handling

To move temperature sensitive goods with full product integrity, supply chain solution providers should have well-established processes from pre-shipment preparation to final verification and delivery to destination.

Product handling is an inherent and important aspect which needs great attention. The maintenance of a cold chain is the best way to maintain the quality of a product and minimize all forms of deterioration after harvesting, including weight loss which results in wilting and limpness, softening, bruising, unwanted ripening, colour changes, texture degradation and the growth of fungus as well as the decay of products.

Page 4: Cold suuply chain

The export of fresh produce often involves long transit time and frequent handling. This makes effective cold chain management more difficult and even more essential, to ensure that the product finally consumed retains maximum freshness.

Importance Of Efficient Cold Chains

Increasing government regulation.The demand from customers for continuously available high quality food products are primary drivers of cold chain integration.

Today’s busy and health conscious consumer is demanding fresh, wholesome and healthy products in increasing volumes and a variety of offerings.

Cold chain systems can be of strategic importance to companies since brand integrity, customer confidence, market share and profit are all at risk.

Improving The Cold Chain

The Budget 2011-2012 provided infrastructure status to the cold chain sector. The Budget exempted air-conditioning equipment and refrigeration panels used in cold

chain infrastructure as well as conveyer belts from excise duty.

The Budget 2010-2011 proposed a concessional import duty of five percent with full exemption from service tax to set up and expand cold chains to preserve farm products as well as milk, meat and poultry products.

The Budget 2010-2011 included duty-free import of refrigeration units, which is required to make refrigerated vans or trucks. It also exempted trailers and semi-trailers used in agriculture from excise duty.

The government of India introduced tax benefits for companies investing in cold chain facilities as part of the budget 2009-2010.

The government of India has also revised its scheme of food parks in the tenth Five Year Plan and changed to the Mega Food Park Scheme (MFPS) under the 11th Five Year Plan

Investment from private equity funds in various cold chain projects.

The involvement of railways and airports for transportation of cold chain products.

The government of India has taken a decision to set up the National Centre for Cold Chain Development (NCCD) to address the issue relating to gaps in cold chain infrastructure in India.

Maintaining and enhancing efficiencies in the cold supply chain is the most important thing. The best way to do this is by reducing touch points in the supply chain. By following these practices rigorously and with passion, we can reduce the cost of the cold chain as well as improve cold chain processes.

Page 5: Cold suuply chain

With average capacity utilization in the cold chain sector between 30 percent to 75 percent, the profits of a cold storage facility depend largely on investment in technology, infrastructure and service standards.

The most important factors that will decide the growth of the cold chain sector is the flow of funds in this sector. The investment can be from large business houses. Also, the government can help in acquisition of land to set up cold chain storage facilities. The government must also speed up the introduction of GST, which will help in the development of centrally located warehouses.

Bank locker example

A cold storage space of this size can be set up for a capital cost of under Rs 7 lakh (land excluded), for a cooling level of 5 degrees C, which will cover most fresh fruit and vegetables. (Temperature and moisture requirements do vary. Meat, for example, needs to be frozen. Even that can be set up.) Each cooler can be run by an owner-operator, throwing up lakhs of rural employment opportunities.

The electricity cost for such a storage locker (5 KW per hour, running 18 hours a day) is estimated at Rs 4,000 per week. Farmers can rent space in the cold locker on usage basis.

The rental cost per 100 cu ft will be just around Rs 400 per week (assuming 50 per cent capacity utilisation, and a target revenue of Rs 10,000 per week to cover electricity cost, manpower and return on investment).

The government can guarantee a return on this infrastructure investment, like it has done for fertiliser plants.

(The real challenge will be access to continuous supply of electricity, a problem that is common to all.)

India can set up 100,000 (500 million cubic feet) of these cold storage lockers in the villages and mandis for a cost of just Rs 7,000 crore.

To put this amount in perspective, the government is spending Rs 40,000 crore on the National Rural Employment Guarantee Act (NREGA), which shows we have the resources.

India can build the largest disaggregated ground-level cold storage chain in the world.

Transportation cold chain

The cost of adding refrigeration to a 7-9 tonne truck is around Rs 6 lakh. An expert in trucking whom I spoke to confirmed that truck operators will add this to their trucks, once they understand the higher rentals they can charge.

Page 6: Cold suuply chain

For a modest investment which can be indigenously funded, we can create a fleet of tens of thousands of refrigerated trucks plying all over the country. The pot-in-pot system, the cold storage locker chain, the refrigerated trucks, and presumably other simple ideas – all of these can be created easily.

FDI in multi-brand retail, with the massive damage it will cause to farmers and traders and the entire ecosystem, is not required to address the cold storage issue.

Instead of handing over our markets and cold chain infrastructure to foreign companies, we can create our own inclusive solution that will be the envy of the world.

Instead of handing over our markets and cold chain infrastructure to foreign companies, we can create our own inclusive solution that will be the envy of the world.

The word “reform” is a euphemism for big foreign capital to gain access to Indian domestic markets in a policy framework that is conducive to their success. The announcement on foreign direct investment in multi-brand retail, currently in ‘pause' mode, is one such example.

One of the major reasons cited for such foreign investment is that this alone is the answer to building our nation's cold storage chain, to reduce wastage of fresh fruits and vegetables.

Let us look at two simple low-cost solutions, both of which can be indigenously developed, tested and deployed on a mass scale.

Lesson from Nigeria

This inspiring example comes from the region around Kano, in northern Nigeria, an area characterised by hot days, low relative humidity and low rainfall that is concentrated within three months.

The region is home to a third of Nigeria's population of over 150 million people. The people are mostly small farmers and cattle-rearers. The area suffers from poor roads and power shortage, making cold storage difficult (a description that applies to vast tracts of India).

Consequently, farmers had to sell their produce at low prices, since they could not hold the produce.After studying the problem in depth, Mohammed Bah Abba, an enterprising lecturer at the Jigawa State Polytechnic, Dutse, came up with a unique solution. Hailing from a family of potters, he invented the pot-in-pot system of cooling (called zeer in local language).

The pot-in-pot technology consists of two earthenware pots of different diameters, one placed inside the other. The space between the two pots is filled with wet sand that is kept constantly moist, thereby keeping both pots damp. Fruit and vegetables are put in the inner pot, which is covered with a damp cloth. The phenomenon that occurs is based on a simple principle of physics: the water contained in the sand between the two pots evaporates towards the outer surface of the larger pot where the drier air is circulating.

Page 7: Cold suuply chain

The evaporation automatically produces cooling, causing a drop in temperature of several degrees in the inner container, extending the life of the perishable foods inside. In tests conducted, the temperature in the inner pot was reduced by 6-8 degrees C in 12 hours, and could be maintained by keeping the sand moist.

The shelf life of the produce improved significantly, as shown in the table.

The impact of the pot-in-pot was a reduction in the wastage of fresh fruits and vegetables. Farmers could hold the produce longer and sell on demand at higher prices. The cost of a pot-in-pot unit is around $5 (less than Rs 300).

Will this work in India? Tests can be run in different States to answer this question. The concept is not new as it is similar to matka-cooled water served in many parts of our country. More than 30,000 units are being sold annually in northern Nigeria. This can't happen unless it is successful.

The cooling required for many perishables is much more than what can be achieved in the pot-in-pot. However, this inexpensive non-electrical system can be the first level of storage in the farmers' homes, for produce which are amenable to this system. Lakhs of these of varying sizes can be deployed at a very low cost.

We all know how a bank locker works. We rent space as required, have access to it when we want, and pay a modest usage fee.

Now, imagine a cold storage room at the village level of size 20' width x 25' length x 10' height – 5,000 cu ft of space. Experts refer to this as a walk-in cooler.

Case: Cold storage project

Cold storage – what’s in store?

India is one of the leading producers of milk, fruits and vegetables. The cold storage industry is trying to keep pace with the country’s production, in order to exploit its immense potential. Arvind Surange brings a report on the development of the sector in the country, with special reference to modernisation of its infrastructure.

THE ABSTRACT

Print this story Email to a friend Download as PDF

Page 8: Cold suuply chain

Discussions Social Share

Cold chain is now recognised as an upcoming sector in India. A country which ranks first in milk production in the world, number two in fruit and vegetable (F&V) production and has substantial output of marine, meat and poultry products, warrants a fully developed and efficient cold chain facilities. Given this scenario, there is tremendous scope for the development of a well-streamlined cold chain sector.

Cold stores form the heart of the cold chain sector. Though cold stores made an entry in India at the beginning of the 20th century, its development as a full-fledged segment was rather slow. The units were typically designed for storage of potatoes and were located in states like Uttar Pradesh, West Bengal Punjab and Bihar. It was only in the 1960s that the idea of multi-product and multi-chamber cold stores was introduced, with Maharashtra taking the lead.

At present, the cold storage sector is undergoing a major metamorphosis, with the Government of India focusing on food preservation. Fortunately, the emphasis is also on energy efficiency as the sector is energy intensive.

With the advent of newer materials and equipment, every link of a cold chain renders itself open to improvement. As a result, construction, insulation, refrigeration equipment and controls are witnessing a sea change.

Realising the significance of the cold chain sector, the Government has taken initiatives through bodies like the National Horticulture Board (NHB) to establish standards to regulate all the components of the sector. Efforts are also being made to evolve the concept of a ‘green cold chain’. In short, the cold chain industry is undergoing both an evolution and a revolution.

The present article will cover the development of the cold storage sector in India with changes in the pattern of utilisation, design, construction practices and energy-saving concepts.

INTRODUCTION

When India got Independence in 1947, there were only a few cold stores, mainly located in Uttar Pradesh, Punjab and West Bengal. Most of them were bulk cold stores designed for storage of potatoes. These were mainly based on old technology and design – thermal insulation and refrigeration systems with practically no automation involved. One of the oldest multi-chamber cold stores was located at the Fruit Research Station in Pune, and was said to be installed in 1932, during the British Rule. This was mainly an experimental station, with seven cold rooms, which worked on a common brine chilling plant. The unit was mainly used for studying cold

Page 9: Cold suuply chain

storage parameters for a variety of fruit and vegetables grown in India. This proves that the concept of multi-product cold storage was realised in the 1930s itself. A few cold stores did come up in Mumbai in the 1950s, with a number of small chambers, mainly used for potatoes, some variety of fruits and dry fruits.

During the period between the 1950s and the 1960s, the development of the cold storage industry was mainly confined to Uttar Pradesh, Punjab, Delhi, Bihar, West Bengal, Madhya Pradesh and Gujarat, where cold stores of medium and large sizes were set up. But these were mainly bulk storage units for potatoes.

Major development of the concept of a multipurpose cold storage unit took off between 1965 and 1970, when a few units were established for storage of a variety of products in Bangalore and Pune.

MAFCO (Maharashtra Agro and Fruit Processing Corporation), a Government undertaking in Maharashtra, established around 1970, played a significant role in promoting the concept of multipurpose cold storage, food processing, freezing and the storage of frozen foods. It was followed by a few private promoters setting up units. But it was not an appreciable number. The capacities of multipurpose units generally ranged from 1,000 MT to 20,000 MT. The largest multipurpose unit with a capacity of 22,000 MT is located in the Turbhe Industrial Area in Navi Mumbai (M/s Savla Foods & Cold Storage).

Presently, the multipurpose units store a large number of food products, such as F&V, dry fruits, spices, milk products, confectionery and all types of frozen food.

THE GROWTH OF COLD STORAGE INDUSTRY

The perishable food production is estimated as:

Milk: 115 Million MT (No. 1 in the world) F&V: 200 Million MT (No. 2 in the world)

Fish: 6.4 Million MT

Meat: Largest cattle population in the world

The food processing sector in India is growing at a steady pace. From an initial two per cent processing capacity, it has now grown to six per cent of F&V production with a present growth rate of about 14% to 15%. The target rate for the F&V processing segment in the next few years has been set at 20%. This shows that there is a great potential for the sector in India.

Page 10: Cold suuply chain

The growth of cold storage industry in India from the year 1955 to 2008 is shown in Table 1. Table 2 shows the region-wise breakup of the numbers of cold stores in different regions based on the data available for the year 2007. It is evident from Table 2 that the distribution of cold stores in different regions of India has not been uniform. Figure 1 additionally shows this region-wise distribution. Table 3 indicates the capacities in the MT of cold stores in different regions. Table 4 shows the sector-wise (public, private and cooperative sectors) distribution of cold stores based on the year 2007. Table 5 shows product-wise distribution of the cold storage capacity in 2007.

PRE-COOLING OF F&V

The concept of pre-cooling of grapes was introduced in the 1980s, primarily in Maharashtra, which is the leading grape-growing state in India. This helped the farmers to export grapes to areas like Europe and the Gulf countries. Later, the technology was adopted for other fruits like mango, pomegranate and orange.

Controlled atmosphere storage:

Page 11: Cold suuply chain

With the onset of the 21st century, the need was felt to set up controlled atmosphere (CA) storage, following trends in Europe, America and other countries. A number of CA stores have now been established in the northern part of the country, at locations which have proximity to the apple-growing regions. The capacities generally range between 1,000 MT and 12,000 MT. A project of 12,000 MT set up by CONCOR (a government body) is the largest in the country so far. A few units of smaller capacities have also been established in western and southern India.

Ripening units:

There has been considerable interest in scientific ripening and storage of fruits like banana and mango in recent years, and units are being established at a number of places. A good development in this direction can be seen in southern India, Gujarat and Maharashtra.

Distribution centres:

With the growth of cold chain in the country, food distribution centres are also being established, with the first such unit constructed in Navi Mumbai. A number of smaller centres have been set up by the food retail sector, and a further growth is expected in the coming years.

COLD STORAGE CLASSIFICATION

As per the present-day practice, cold stores can be classified as follows:

Bulk cold stores – generally for storage of a single commodity, which mostly operate on a seasonal basis, for example, storage for potatoes, chillies and apples.

Multipurpose cold stores designed for storage of a variety of commodities, which operate round the year. The products stored in these types of cold stores are fruit, vegetables, dry fruits, spices, pulses and milk products. These units have been mainly located close to consumption centres.

Page 12: Cold suuply chain

Small cold stores with pre-cooling facilities for fresh F&V, mainly, for export-oriented items like grapes. The major concentration of these units is in Maharashtra. But the trend is now picking up in other states like Karnataka, Andhra Pradesh and Gujarat.

Frozen food stores with or without processing and freezing facility for fish, meat, poultry, dairy products and processed F&V. These units have helped the promotion and growth of the frozen food sector, both in the domestic and export markets. However, the percentage of food so processed is extremely low. There is a great potential for the growth in this category.

Mini units/walk-in cold stores located at hotels restaurants, malls and supermarkets.

CA stores for certain F&Vs like apples, pears and cherries.

Ripening chambers mainly set up for bananas and mangoes.

TRENDS IN CONSTRUCTION PRACTICES

While the bulk cold stores have fewer large-sized chambers, the multi-purpose units have a larger number of smaller chambers designed for the simultaneous storage of a variety of items to suit the needs of farmers, traders and customers. The general types of construction followed in the Indian cold storage industry are as under:

Conventional buildings with RCC frames, brick walls and truss-type sheet roofs or RCC slabs with internal floor structure of RCC or steel frame with wooden or steel grating

Buildings with a single floor structure designed for mechanised loading and unloading of products

Pre-engineered building structures designed with cold chambers constructed from sandwich-insulated panel

The latest trend is to have cold chambers in a single-floor construction, with heights varying from five to 12 metres or higher, with mechanised loading/unloading facilities. Some units have racks for stacking the goods.

Recent practices are:

Walls and ceiling: Insulated panel construction

Roof: Sheet metal roofing on trusses

Page 13: Cold suuply chain

Internal structures:

a) Steel structure with steel grille floors for conventional loading

b) Racks for mechanised loading

Construction practices in India vary, depending on the size of the unit, location and pattern of utilisation. Small cold stores usually have sandwich-panel construction.

In case of medium and large cold stores, the facilities involve a) Loading/unloading areas

b) Ante rooms

c) Cold storage chambers

d) Staircases and lifts

e) Machine room

f) Office, toilets and other facilities.

Conventional buildings have multi-floor chambers, where loading and unloading is done manually. The floor height ranges from two to 2.5 metres, and the number of floors from three to six.

Page 14: Cold suuply chain

The evolution of the cold storage construction practice is shown in the four figures depicted as follows:

TRENDS IN THERMAL INSULATION PRACTICES

Thermal insulation is an extremely important component in a cold chain system. It performs two vital functions:

1. To minimise the flow of heat from the surrounding areas to the inside space

2. To minimise the flow of moisture from surrounding areas to cold chambers

It is, therefore, important to select proper material with the right thickness, vapour barrier, cladding and the method of application to ensure that the basic objectives of providing thermal insulation are fulfilled in the best possible manner. It needs to be kept in mind that while the refrigeration system works for certain number of hours, depending on the load requirement, the insulation is on a continuous 24×7 duty for the entire period of storage.

Page 15: Cold suuply chain

Insulation materials

In some old units, cheaper material, like rice husk, was once used as thermal insulation. Although the insulation itself was very cheap, it necessitated very large insulation thicknesses and also caused maintenance and hygiene problems. This method is almost extinct now.

In cold stores, having conventional construction built after the 1970s, the general practice has been to use insulation materials like Expanded Polystyrene (EPS), fibreglass, Polyurethane Rigid Foam (PUF) or similar materials. Recently, materials like Extruded Polystyrene (XPS) have also been introduced.

The old practice in case of conventional construction was to fix the insulation with bitumen as vapour barrier and using wooden pegs and batten framework, covered with chicken wire mesh and cement and sand plaster. However, the current practice is to avoid the use of wooden battens and use metallic runners instead, to support the sheet metal cladding, which are generally profiled pre-coated sheets.

Sandwich-insulated panel structure

The development of insulated panels has ushered in a revolution in the cold storage construction the world over. Although, these panels have been in use for cold storage construction for over four decades in the developed countries, in India, sandwich panels were introduced only about 25 years ago. Sandwich panels are mainly available in two types:

1. EPS panels, with EPS bonded to the sheet metal skins by using a special type of glue

2. PUF panels using Polyurethane as insulation material foamed between the two metal skins. These panels are structurally strong and have a better insulation value as compared to EPS panels for a given thickness

Insulated panels have been used for making cold stores, right from the small walk-ins to very large cold stores. In fact, the application of panels has gone beyond the cold storage sector, and the panels are being used for construction of processing plants, prefabricated houses, warehouses, clean rooms and the like. The panels have also been used for fabricating doors for cold stores, which are light and simple in construction, compared to the conventional insulated doors.

The panels offer greater flexibility and a faster pace of construction, apart from better thermal efficiency due to better isolation between the outside and the inside areas. The use of panels eliminates brick walls and RCC slabs, thereby increasing the cold store volume for a given

Page 16: Cold suuply chain

footprint. The major advantage is the possibility of modular construction with ease of addition or expansion. Panels are available with different types of skin finish and offer a better hygienic environment to the structure.

TRENDS IN REFRIGERATION SYSTEM

Over 90% of the cold store units built in the northern and the eastern parts of India were based on old technology, involving use of slow-speed ammonia refrigeration compressor, without any capacity control, atmospheric condensers and either bunker-type evaporator coils or floor-mounted air cooling units (diffusers) with ducting for air distribution. These plants were not very energy efficient, due to lack of capacity control, loss of expensive cold storage space for large-sized bunker coils or diffuser units and associated ducting.

The current practices involve energy-efficient designs of equipment and use reciprocating and screw compressors with capacity control, evaporative condensers with MS (hot-dip galvanised) or SS coils and ceiling-suspended finned air- cooling units using MS or SS coils with aluminium fins. The types of fans used in the units have SS/aluminium or FRP blades. The FRP option offers the benefit of lower HP motors for the fans.

Refrigeration systems for cold storage application can be classified as:

Modular units using HFC/HCFC refrigerant Central plants using HFC/HCFC refrigerants with air- cooled/water-cooled machines

Central plants using ammonia refrigerant

Vapour-absorption system using ammonia-water combination. This system is now being considered for rural areas due to availability of alternative fuels like biogas and agrofuel.

Material handling

The flow of products to and from the cold store is an important aspect in cold storage functioning. In conventional cold stores, the loading and unloading of products is still done manually. However, in recent installations, the practice is to use electrical hoists/lifts and/or forklift trucks for handling of products. These storages incorporate rack structures in the chambers for storing products in pallets or boxes. Arrangement for loading of pallets in containers and reefer vans is also provided in the modern cold store units. Use of computers to control loading, unloading operations and to maintain the record of stocks is also in practice in some of the new colds stores.

Page 17: Cold suuply chain

Energy saving

Cold storage is the heart of the cold chain. Refrigeration is the fundamental process for cooling, pre-cooling, freezing and cold storage. Among the various methods of food preservation, refrigeration is the best one, and there is no substitute for it in terms of quality and extended life. However, refrigeration is an expensive process, both in terms of first cost and energy cost.

Lack of adequate energy supply and rising energy rates are serious problems faced by the cold storage sector. Owners and manufacturers in the sector have increasingly begun to realise the need for adopting various energy-saving methods.

In recent years, the Green Building movement has attracted the attention of planners, designers, builders and contractors the world over. The author has also propagated the concept of ‘green cold chain’ involving green cold stores in India.

CONCLUSION

An overview of the cold chain system in India over the past five to six decades shows that cold storage construction technology, practices of thermal insulation, refrigeration plant technology, automation and material handling have undergone significant transformation. From the point of view of utilisation, too, the cold stores today offer a much wider scope than in the past. Energy-saving and ‘green cold chain’ concepts are also being seriously looked at by progressive entrepreneurs and designers. However, it must be noted that for a country which is a frontrunner in milk production and in the second position in F&V production, the overall storage capacity of around 25 million MT of cold storage available in the country cannot be considered adequate. Thus, there appears to be a good potential for the development of modern and energy-efficient storage units.

The NHB has taken a big step forward in establishing technical standards for cold chain projects. The following three standards have been developed with the help of experts in the industry, and are available to the promoters and designers of cold chain projects for reference:

(i) Cold storages for storage of fresh horticulture products which do not require pre-cooling

(ii) Multi-commodity cold storages for short-term and long-term storage of fresh horticulture products which require pre-cooling and varying storage requirements

(iii) CA storages

Page 18: Cold suuply chain

Apart from these, the standards on ripening chambers and refrigerated transport have also been recently released for public review. It is worth mentioning that this is the first attempt by any Government agency to formulate such standards for cold chain projects in India. Efforts are on for establishing standards for ripening chambers and refrigerated transportation. Government agencies like the NHB, National Horticultural Mission and the Ministry of Food Processing have also offered higher financial incentives for new projects as well as for expansion of existing units. However, these projects have to be essentially based on modern and efficient technology so that they are in tune with the new technical standards.

A scientifically developed cold chain, designed to handle and preserve the quality and quantity of food products grown in the country, would turn into a ‘gold chain’ for the country.