BLUE STAR LTD. Ghatkoper, Mumbai

Industrial Training ReportOn

COLD CHAINUnder Supervision of

R. Ramanujan(Manager – Project Manager)

BLUE STAR LTD.

Galgotias College of Engineering And Technology,

Gr.Noida

Submitted by:

ASHIsh kumar singh

b.tech (ei)

IVth year

Certificate

It is certified that ASHISH KUMAR SINGH done training in BLUE STAR lTD. Ghatkoper, Mumbai and has presented in the report for the award of bachelor of technology from Uttar Pradesh Technical University (UPTU), Lucknow.

The training report embodies the original work and studies carried out by the student himself and the content do not form the basis for the award of any degree to the candidate or anybody else.

Mr. dhirendra kumar Mrs. Nandita pradhan (Faculty Incharge) Head of Department Sr. lecturer Electronics and InstrumentationElectronics and Instrumentation

Date: Date:

preface

This project gives Rich insight about the various cold chain of BLUE STAR lTD. Ghatkoper, Mumbai & also about various facilities provided by the company to its customers.

Moreover this project will also help in learning Practical Aspects of different functions of Instrumentation Department which are very necessary to become a good instrument engineer.

content

Acknowledgement Introduction History Guiding values and believes Milestone Corporate Social Responsibility Manufacturing Systems Manufacturing Equipment Assembly and Testing Factsheet Cold chain Refrigerant History of Refrigerant

Classification of refrigerants Classification of refrigerants Desirable properties of a good refrigerant

Controlled Atmosphere Storage Importance of Controlled Atmosphere CA Storage Rooms CA Development CA Transport References

Acknowledgement

This project report has been made possible through the direct

cooperation of various members of Blue Star ltd. Ghatkoper,

Mumbai family as they help me a lot in one or the other way in

the completion of my project work.

I specially thanks Mr. R. Ramanujam(Manager – Project

manager) at BLUE STAR lTD.. Ghatkoper, Mumbai as under

their guidance I came to know about theoretical aspect of day to

day life in origination.

In the end I would like to give my sincere thanks to Blue Star ltd. Ghatkoper, Mumbai for providing us excellent tools and working environment, which led to the successful completion of my training report on time.

ASHISH KUMAR SINGH

B.TECH (EI)

IVth year

Introduction

Blue Star is India's largest central air-conditioning company with an annual turnover of Rs 2556 crores, a network of 29 offices, 5 modern manufacturing facilities, 700 dealers and around 2600 employees.

It fulfills the air-conditioning needs of a large number of corporate and commercial customers and has also established leadership in the field of commercial refrigeration equipment ranging from water coolers to cold storages. The Company has also started offering Electrical Contracting and Plumbing & Fire Fighting Services.

Blue Star has business alliances with world renowned technology leaders such as Rheem Mfg Co, USA; Hitachi, Japan; Eaton - Williams, UK; Thales e-Security Ltd., UK; Jeol, Japan and many others, to offer superior products and solutions to customers.

The Company has manufacturing facilities at Thane, Dadra, Bharuch, Himachal and Wada which use state-of-the-art manufacturing equipment to ensure that the products have consistent quality and reliability.

Blue Star primarily focuses on the corporate and commercial markets. These include institutional, industrial and government organizations as well as commercial establishments such as showrooms, restaurants, banks, hospitals, theatres, shopping malls and boutiques. In accordance with the nature of products

and markets, business drivers, and competitive positioning, the lines of business of Blue Star can be segmented as follows:

Cooling ProductsBlue Star offers a wide range of contemporary window and split airconditioners. The Company also manufactures and markets a comprehensive range of commercial refrigeration products and services that cater to the industrial, commercial and hospitality sectors. These include water coolers, bottled water dispensers, deep freezers, cold storages, bottle coolers, ice cube machines and supermarket refrigeration products.

Electro Mechanical Projects and Packaged Airconditioning SystemsThis comprises central and packaged airconditioning as well as electrical projects and plumbing & fire fighting projects. The central and packaged airconditioning business involves design, engineering, manufacturing, installation, commissioning and support of large central airconditioning plants, packaged airconditioners and ducted split airconditioners. In addition to this, Blue Star promotes after-sales service as a business, by offering several value added services in the areas of upgrades and enhancements, air management, water management, energy management and LEED consultancy for Green Buildings.

The Company also executes building electrification contracting projects and offers expertise in the areas of electrical design and

engineering, supply and installation of entire power systems as well as liasioning, approvals, commissioning and asset management.

Blue Star has extended its mechanical contracting offering to include plumbing and fire fighting projects. With this, Blue Star has developed capabilities for executing integrated MEP (Mechanical, Electrical and Plumbing) projects.

Professional Electronics and Industrial SystemsFor over five decades, the Electronics Division has been the exclusive distributor in India for many internationally renowned manufacturers of hi-tech professional electronic equipment and services, as well as industrial products and systems. The Company has carved out profitable niches for itself in most of the specialized markets it operates in, such as such as Industrial Projects, Industrial Products and Systems, Material Testing Equipment and Systems (Destructive / Non Destructive), Data Communication Products & Services, Testing and Measuring Instruments, Analytical Instruments and Medical Diagnostic Equipment.

History

Blue Star was founded in 1943, by Mohan T Advani, an entrepreneur of exemplary vision and drive. The Company began as a modest 3-member team engaged in reconditioning of airconditioners and refrigerators.

Within three years, the Company secured the agency for US-based Melchoir Armstrong Dessau's airconditioning equipment. Shortly after, the Company was selected by Worthington, the US leader in airconditioning, as its India based partner - these were the first of numerous foreign associations to follow.

An expanding Blue Star then ventured into the manufacture of ice candy machines and bottle coolers and also began the design and execution of central airconditioning projects. Then came the manufacture of water coolers. In 1949, the proprietorship company set its sights on bigger expansion, took on shareholders and became Blue Star Engineering Company Private Limited.

The sixties and the early seventies witnessed Blue Star continuing to expand and thrive. A team of dedicated professionals aided Mohan T Advani in ever furthering his vision of a profitable company dedicated to its ideals of professionalism and success. Employee strength crossed the 1000 mark and the company went public in 1969 to become Blue Star Limited, as it continues to be called today.

In 1970, the Company took up the all-India distributorship of Hewlett-Packard products, a business relationship which continues today and has grown ever stronger through the years. As the Company's reputation for delivering the goods in the most challenging of airconditioning projects grew steadily, the early seventies saw a series of prestigious projects being entrusted to Blue Star - skyscrapers such as Air India Building, Express Towers, the Oberoi Hotel in Mumbai, apart from several others. Revenues touched the Rs. 10-crore mark and staff strength doubled to exceed 2000.

As its Indian presence reached greater heights, the Company began building determinedly upon its existing overseas presence, Blue Star set up a joint venture with Al Shirawi in Dubai and went on to execute some outstanding projects in Syria, Iraq and Saudi Arabia. To complement its airconditioning projects and undertake turnkey industrial projects, an Industrial Division was set up in 1978.

Always moving with the times and ever on the lookout for business possibilities, Blue Star next set up a software export unit at Seepz, Mumbai in 1983. Then came associations with more global leaders - a collaboration with York International of USA for central airconditioning equipment and joint ventures with Motorola and Yokogawa.

In 1984, Ashok M Advani & Suneel M Advani, the sons of Mohan T Advani, took over the reins of the Company, after spending nearly 15 years within the Company steadily climbing up the ladder. A renewed thrust was placed on the company's core business areas - airconditioning and refrigeration and the

distribution of professional electronics equipment - and the company emerged a market leader in these focus areas.

The nineties witnessed India entering an era of economic liberalisation and an upsurge in competition as the dynamic business scenario attracted the world's most forward-looking corporations. It was time to re-look at existing business competencies, re-engineer those that were obsolete and forge ahead in acquiring new business competencies. Blue Star was more than equal to the challenge and expansion continued unabated.

In keeping with this focus, an advanced manufacturing facility was set up at Dadra in 1997, in technical collaboration with Rheem, USA, to enhance manufacturing competency. Today it bears the distinction of being regarded as the best such plant India-wide. The dealer network was strengthened and expanded to bring products within easy reach of every customer.

With the advent of the much awaited new millennium in 2000, the action continued. The software unit was spun off into a separate company, Blue Star Infotech Ltd., the export of airconditioning products from the Dadra factory began and contract manufacturing for local and foreign brands commenced. A new Corporate Vision was developed - "To deliver a world-class customer experience". Every employee is determined to follow this vision and keep their organization a competitive and forward-looking one.

Blue Star crossed the Rs. 500 crore milestone in 2000 and the Rs. 600 crore milestone in 2002-03. With the boom in construction activity and increased infrastructure investments,

the Company leveraged its leadership position to grow aggressively. In the following three years, the Company nearly doubled its turnover, clocking Rs 1178 crores in 2005-06.

Guiding values and believes

To deliver a world class customer experience. Focus on profitable company growth. Be a company that is a pleasure to do business with. Work in boundary less manner between divisions to

provide the best solution to the customers. Win our people’s hearts and minds. Place the company’s interest above one’s own. Encourage innovation, creativity and experimentation in

what we do. Build an extended organization of committed business

partners. Be a good corporate citizen. Maintain personal integrity. Ensure high quality of corporate governance.

MILESTONES

Year Event

1943 Mohan T Advani establishes Blue Star Engineering Company as a proprietary firm

1946 Blue Star secures Melchior Armstrong Dessau agency

1947

Worthington selects Blue Star as Indian Partner. Manufacturing of ice candy machines and bottle coolers begins. Central airconditioning system design and execution begins

1948 Manufacture of water coolers commences1949 Proprietorship converted to Private Limited Companies1954 Blue Star selected as distributor for Honeywell1955 GDR Testing machines distributorship begins

1957 Perkin-Elmer tie-up marks the start of the electronics business. GDR business machines agency commences

1960 Total Income crosses the Rs 1 crore mark1962 GDR Machine Tools distributorship begins1964 Total employment crosses 1,000

1965 Techniglas Pvt Ltd set up to manufacture insulation material

1969 Factory moves from Colaba in Mumbai to Thane1970 Hewlett- Packard distributorship commences

1972First skyscrapers of Mumbai – Air India Building, Express Towers and Oberoi Hotel set-up – all airconditioned by Blue Star

1972 Total Income crosses Rs 10 crores. Employment crosses 2,000

1974 Water Cooler manufacturing license granted to Yusuf Alghanim, Kuwait

1977 Middle East thrust begins. Joint Venture (JV) with Al Shirawi in Dubai

1978 Industrial Division commences activity1980 Bharuch Factory set up1980-86 Major AC and R projects executed in the Middle East

1983 International Software Division inaugurated in Seepz1984 York technology collaboration begins

1985 Manufacture of centrifugal packaged chillers commences at Thane Plant

1986 Total Income crosses Rs 100 crores1987 Yokogawa Blue Star JV formed1987 Gandhinagar factory set up for EPABX systems

1988 Blue Star becomes India’s largest central airconditioning company

1988 Assembly of personal computers under the brand name ‘Quantum’ begins

1989 JV with Hewlett-Packard and Motorola

1990 Gandhinagar factory closes1992 Total Income crosses Rs 200 crores1992 Blue Star exits from Motorola JV1993 Formation of Arab Malaysian Blue Star JV in Malaysia 1995 Blue Star exits from HP India JV1997 Dadra Plant inaugurated

1998 Major thrust on dealerisation and brand building begins

1999 Blue Star exits from Industrial Projects business

2000 International Software business spun off to form Blue Star Infotech, listed on stock exchanges

2003 Blue Star exits Yokogawa JV

2005 Blue Star sets up new factory at Kala Amb in Himachal Pradesh

2006 Total Income crosses the Rs 1000 crores mark2006 Blue Star opts for a 5 for 1 stock split

2007 Blue Star sets up its fifth factory at Wada, Thane District

2008Blue Star powers into Building Electrification. Acquires Naseer Electricals, a leading Electrical Contractor

2008 Total income crosses Rs. 2000 Crores.

Corporate Social Responsibility

Blue Star’s Corporate Social Responsibility (CSR) philosophy is built on three pillars namely

Environment protection Energy conservation Community development around its facilities.

The Company is highly committed to the cause of protecting the environment. Energy efficiency of its products remains a corner-stone of its research and development efforts Air, water and energy management services as well as LEED (Leadership in Energy and Environmental Design) consultancy for Green Buildings have been part of its business and practices. The Company has also been contributing in the technical domain in the use of eco-friendly refrigerants in its products.

Energy Conservation goes beyond using efficient products. A huge amount of energy is wasted nationally due to sheer ignorance and lack of awareness. Blue Star helps deserving institutions such as hospitals and colleges to save power by conducting free walk-through energy audits. The Company has conducted several such audits with energy recommendations for Jai Hind College, St Xavier’s College, Nirmala Niketan College of Social Work, National Association for the Blind (NAB),

Bombay Natural History Society (BNHS), JJ School of Architecture and Dilkhush Special School, amongst others.  

In its efforts towards community development around the Company’s facilities, the Company has initiated and sponsored a study in the villages around its Wada Plant to understand the immediate needs. Vocational training and health emerged as pressing needs in this underdeveloped region. Blue Star has sponsored the vocational training courses offered by an NGO, KSWA in Wada. This centre was set up to support a vocational training initiative for school and college dropouts to make them employable contributing members of their families and communities. Regular visits by the Company’s employees have aided in technical support to KSWA for conducting the courses.

Manufacturing Systems

The factories make extensive use of IT to enhance productivity and product development capabilities.All our factories are ISO 9001: 2000 certified

BAAN ERP implemented in 3 factories and Himachal under implementation

Manufacturing FacilitiesBlue Star has five modern state-of-the-art manufacturing facilities located at Thane, Bharuch, Dadra, Himachal and Wada. Extensive product testing facilities enable the development of high quality products manufactured at the factories.

Blue Star Factories

Thane

Factory Facts:

1st factory of Blue Star established in 1960 situated in Maharashtra near the commercial capital Mumbai.Area: 7500 sq.mtManpower: 250

The plant's processes are all integrated through BaaN ERP. Modern softwares like Pro-E are used for designing products. Also, customized software has been developed for selection of AHU's and Chillers. All modern manufacturing concepts have been incorporated notable among them being visual management of the factory, Just In Time, kaizen, 5S, Kanban, TPM, PPM and Pokayoke.

Wada

Factory Facts:

Started in 2007 Area: 24000 sq.mts Manpower: 100

Wada facility is the most recent plant set up by the Company, situated around 60 km from Thane, near Mumbai. With a plot size of around 36 acres, this facility is planned to eventually be Blue Star’s biggest manufacturing facility. Modern manufacturing systems are being deployed with the focus on quality systems through programmes like Lean Manufacturing, Six Sigma, TPM and Kaizen.

Bharuch

Factory Facts:

Blue Star's second factory started in 1980 in Gujarat, which is 400 kms north of Mumbai

Area: 13500 sq.mtManpower: 320

Dadra

Factory Facts:

Started in: 1997 Situated in Dadra and Nagar Haveli, a Union Territory situated 200 kms away from Mumbai and having its capital at Silvassa.Area: 12000 sq.mtManpower: 300

Dadra plant is regarded by industry experts as one of the best manufacturing facilities in the country for airconditioning products. It's been built in technical collaboration with Rheem USA.

Himachal

Factory Facts:

Started in 2005 This factory is 300 kms North West of North Delhi. Area: 14,000 sq.mts Manpower: 100

This factory has been set-up in the sylvan settings of Kala-amb in Himachal Pradesh. The industrial zone of Baddi has seen a proliferation of manufacturing setups in the recent past, thanks to the benevolent tax concessions granted by the Government.

Manufacturing Equipment

System Tubing3-axis CNC copper tube-bending machines from Japan fabricate wrinkle-free system tubing to exact dimensions for a perfect stress-free fit. Special purpose machines carry out operations like end closing, flaring and forming for good joint formation. Prime quality copper tubes sourced globally help in optimum product performance.

Sheet Metal FabricationA high degree of repetitive accuracy in sheet metal fabrication is achieved by using specialized equipment, CNC metal forming machines. The raw material used is prime quality, corrosion-resistant, galvanized steel for enhanced life of the product. The equipment used for processing the steel includes CNC machines such as an Amada turret punch press, a LVD / Amada hydraulic press-break. All these allow for high quality cabinet fabrication within tight tolerances.

PUF Insulation We fabricate CFC-free PUF insulated panels by using the latest equipment from Cannon. This enables us to achieve a uniform and constant density of insulation for air handling units, telecom shelters and cold storage panels. We supply panels of up to 6 meters in length and 25 mm to 125 mm in PUF thickness. Our PUF insulation expertise finds use in a wide range of applications such as Air Handling Units, water coolers, deep freezers, reach-in coolers and mortuary chambers.

Heat ExchangersExperienced engineers create heat exchanger designs using high precision design software, which are then validated in our test labs. We also make sure that our designs are energy efficient for optimum heat transfer.

Shell and Tube: We have shell and tube exchangers using specially enhanced surface copper tubes and shell design as per Blue Star or TEMA standards. We use Heat Transfer Research Inc. (HTRI design software for these heat exchangers).

Fin and Tube: Our sophisticated coil shops have some of the most advanced machines from USA, Japan and Korea. The Burr Oak coil line produces energy efficient DX heat exchangers. These have plain or enhanced split fins with grooved copper tubes for maximum heat transfer efficiency. We source plain and inner grooved copper tubes with coated

aluminum fin stock of international quality from leading manufacturers to fit our specifications.

Plate Type: Blue Star products also incorporate stainless steel plate heat exchangers for specialized process applications.

BrazingThe brazing process is carried out in an inert atmosphere to avoid oxidation and the resultant impurities from contaminating the refrigerant system. Specially selected brazing equipment and fixtures are used to produce high quality brazing. The joints are pressure-tested to check weld strength and leakage. The coils are then tested for fine leaks with ultra-sensitive electronic leak detectors. An automated coil brazing line from Korea ensures consistent quality brazing and leak proof joints.

Powder Coating PlantThe state-of-the-art powder coating plant covers a wide range of very specialized process equipment, and is fully automated. A water-softening unit treats the raw water before it is utilized in the automatic hot spray pre-treatment system. It provides an even distribution of chemicals, controlled by an auto dosing mechanism that maintains the chemical bath composition with the help of electronic sensors. After a final mineral water rinse, the components pass through a dry-off oven under dust-free conditions to remove all traces of moisture.

The components are then transferred into the powder painting booth for coating, where temperature, humidity and dust levels are controlled. The powder painting equipment, supplied by Nordson, USA, is equipped with automatic electromechanical oscillators, for even powder deposition.

Desiccant dry air-with a dew point of minus 400 C - helps avoid any moisture contamination of the powder. A 'smart spray' mechanism senses the conveyor movement and component geometry to adjust powder flow.

Polyester powder - ideally suited for out door applications - provides the maximum protection against UV deterioration and corrosion.

The components finally pass through a temperature-regulated curing oven to achieve desired gloss and surface hardness.

An accelerated life-test result of 1,000 hours in a salt spray chamber confirms the process capability of this world-class paint shop.

Assembly and Testing

The final product is assembled sequentially on conveyors, with in-built quality checks during assembly operations. Pneumatic tools permit torque-controlled rigidity, and specially coated corrosion-resistant hardware provides firm locking.

Each machine is then electronically tested for leaks and run-tested for performance and electrical safety parameters before packaging.

Test Facility

Substantial investments have been made in setting up sophisticated test laboratories. All the test labs comply with international standards and boast of state-of-the-art instrumentation systems.

We also believe in constantly upgrading product design and manufacturing technologies to produce cost effective customized solutions. This ensures that demands on reliability, flexibility and process capability are constantly met, keeping customer needs in mind, focus is also kept on creative design, innovation and frequent up gradation of products.

FCU & AHU Test Lab Specification Cooling Capacity : 0.5 TR to 4 TR (FCU) / 4 – 15

TR (AHU) Air flow measurement : 150 to 1600 CFM (FCU) /

1600 to 2000 CFM (AHU) Water flow : 1 to 30 USGPM / 8 to 45 USGPM Water temp : 5 to 25 C (AHU & FCU) Performance testing : Indoor temperature 15 deg.

C to 55 Deg. C and Relative Humidity 20% to 90% Measurement of capacity from Air side and Water side.

Compliance Standards:

ARI 440, 2005 : Performance rating of Room Fan Coils

ASHRAE 33-2000 : Method of testing forced circulation Air Cooling and Air Heating Coils

ASHRAE 79-1984 : Method of testing for rating Room Fan-Coil Air Conditioner

ASHRAE 41.2-1987 : Standard Methods for Laboratory Airflow Measurement

AHSRAE 41.1-1986 : Standard Measurement Guide, Section on Temperature Measurements

Reliability Test LabTest facilities available:

Environmental Test High temperature chamber (50°C to 250°C) Low temperature bath (-20°C to 40°C) Low temperature chamber (-5°C to 25°C) UV chamber (Day light wave length) Salt spray chamber (5%NaCl and 95%Water, temp : 35°C,

Duration : 1000Hours) Rain shower test facility (25mm/min with adjustable

nozzle)

Endurance Test Electrical ON/OFF cycling.(Can vary cycle time and count

number of cycles) Pneumatic ON/OFF cycling.(Can vary cycle time and count

number of cycles)

Vibration Test Facility Transportation vibration simulation (Variable frequency

20Hz to 50Hz) Capable of test UUT weight 400Kg

Electrical Test Equipments

IR meter (500VDC) HV tester Lock rotor tester (Monitor and stores V/A/W/Temperature

of UUT) Digital Current/Voltage/power meter (For single and three

phase UUT) Oscilloscope Digital multimeter

Chiller Test Lab Specification Water Cooled Chillers: Cooling Capacity 40 TR to

200 TR Air Cooled Chillers: Cooling Capacity of 25 TR to

200 TR Ambient Conditions: 35 deg. C to 55 Deg. C Water flow measurement: Cooler upto 600

USGPM Water flow measurement: Condenser upto 800

USGPM Water side pressure drop through Cooler and Condenser

upto 2 Kg/cm2

Compliance Standards:

ASHRAE 30-78: Method of testing liquid chilling packages

ARI 550/590: Water Chilling Packages using the vapor compression cycle

Factsheet

Total Income Growth: Rs. 2556.11 Cr

Operating Profit Excluding Non-operating income: Rs.

299.16 Cr

Profit Before Tax: Rs. 276.62 Cr

Profit After Tax: Rs. 211.49 Cr

Shareholders' Funds: Rs. 491.68 Cr

Borrowings: Rs. 8.93 Cr

Capital Employed: Rs. 500.61 Cr

Cold chain

A cold chain is a temperature-controlled supply chain. An unbroken cold chain is an uninterrupted series of storage and distribution activities which maintain a given temperature range. It is used to help extend and ensure the shelf life of products such as fresh agricultural produce, frozen food, photographic film, chemicals and pharmaceutical drugs.

Cold chains are common in the food and pharmaceutical industries and also some chemical shipments. One common temperature range for a cold chain in pharmaceutical industries is 2 to 8 °C.but the specific temperature (and time at temperature) tolerances depend on the actual product being shipped.

Refrigerant

A refrigerant is a medium of heat transfer through phase change such as evaporation at low temperature and pressure, of course with some exception where the sensible energy transfer occurs.

So a refrigerant may be defined as any substance that absorb heat either by expansion or vaporization and reject it through condensation in condenser .

UsagesRefrigerants

ApplicationR-12 Domestic refrigerants, freezer

R-12, R-22, R-502 Small retail supermarkets

R-11, R-12, R-144, R-502 Air-conditioning

R-22, ammonia Industrial

R-12, R-502 Transport

CO2 Automobile

Propane Refrigerators

History of Refrigerant

Until concerns about depletion of the ozone layer arose in the 1980s, the most widely used refrigerants were the halomethanes, R-12 and R-22, with R-12 being more common in automotive air conditioning and small refrigerators, and R-22 being used for residential and light commercial air conditioning, refrigerators, and freezers. Some very early systems used R-11 because its relatively high boiling point allows low-pressure systems to be constructed, reducing the mechanical strength required for components. New production of R-12 ceased in the United States in 1995, and R-22 is to be phased out by 2020. R-134a and certain blends are now replacing chlorinated compounds. One popular 50/50 blend of R-32 and R-125 now being increasingly substituted for R-22 is R-410A, often marketed under the trade name Puron. Another popular blend of R-32, R-125, and R-134a with a higher critical temperature, and lower GWP than R-410A is R-407C. While the R-22 and other ozone depleting refrigerants are being phased out, they still have value and can be easily sold.

Following the ban on chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs), substances used as substitute refrigerants such as fluorocarbons (FCs) and hydrofluorocarbons (HFCs) have also come under criticism. They are currently subject to prohibition discussions on account of their harmful effect on the climate. In 1997, FCs and HFCs were included in the Kyoto Protocol to the Framework Convention on Climate Change. In 2006, the EU adopted a

Regulation on fluorinated greenhouse gases, which makes stipulations regarding the use of FCs and HFCs with the intention of reducing their emissions. The provisions do not affect climate-neutral natural refrigerants.

Early mechanical refrigeration systems employed sulfur dioxide gas or anhydrous ammonia, with small home refrigerators primarily using the former. Being toxic, sulfur dioxide rapidly disappeared from the market with the introduction of CFCs. Ammonia (R717) has been used in industrial refrigeration plants for more than 130 years and is deemed to be environment-friendly, economical, and energy-efficient. The natural refrigerant carbon dioxide (R744) has a similarly long tradition in refrigeration technology.

Occasionally, one may encounter older machines which used other transitional refrigerants such as methyl formate, chloromethane, or dichloromethane (called carrene in the trade). Perhaps the most common of these to still retain a charge are the methyl formate Monitor Top refrigerators produced by General Electric.

Use of highly purified propane as a refrigerant is gaining favor, especially in systems designed for R-22. Moreover, propane is non-toxic. An odorant, such as ethyl mercaptan, can be added in trace amounts to alert persons of system leaks.

Classification of refrigerants

1.) Based on working principle:Refrigerants may be divided into three classes according to their manner of absorption or extraction of heat from the substances to be refrigerated:

Class 1: This class includes refrigerants that cool by phase change (typically boiling), using the refrigerant's latent heat.

Class 2: These refrigerants cool by temperature change or 'sensible heat', the quantity of heat being the specific heat capacity x the temperature change. They are air, calcium chloride brine, sodium chloride brine, alcohol, and similar nonfreezing solutions. The purpose of Class 2 refrigerants is to receive a reduction of temperature from Class 1 refrigerants and convey this lower temperature to the area to be air-conditioned.

Class 3: This group consists of solutions that contain absorbed vapors of liquefiable agents or refrigerating media. These solutions function by nature of their ability to carry liquefiable vapors, which produce a cooling effect by the absorption of their heat of solution.

2.) Based on chemical compounda.) Halocarbon compounds: Halocarbon compounds contains one or more no. of halogens, chlorine, fluorine, and bromine commercial name GENETRON, ISOTRON and ARETRON.

These have wide range of boiling point and presence of Florence make it toxic.

e.g.R-11-----CCl3F R-12-----CCl2F2

R-13-----CClF3 R-21-----CHCl2F

b.) Azeotropes: Azeotropes is mixture different refrigerant which can not be separated under pressure and temperature and they have fixed thermodynamic properties.

e.g. R-500 is mixture of 73.8% of R-12 and 26.2% of R-152.

c.) Hydrocarbon: Hydrocarbon are used as refrigerant for commercial and industrial application.

Have desirable thermodynamic properties. Highly inflammable.

e.g. R-50 Methane R-170 Ethane

R-230 Propane R-600 Butane

d.) Inorganic: used before hydrocarbon

e.g.

R-717 NH3 R-744 CO2

R-718 H2O R-729 AIR

R-764 SO2

e.) Unsaturated O.C.:Ethylene and Proplyene based O.C

e.g.

R-1120 C2HCl3 R-1130 C2H2Cl2

R-1150 C2H4 R-1270 C3H6

3.) based on safety: a.) Toxicity classification

Refrigerants are divided into two groups according to toxicity:

Class A signifies refrigerants for which toxicity has not been identified at concentrations less than or equal to 400 ppm;

Class B signifies refrigerants for which there is evidence of toxicity at concentrations below 400 ppm.

b.) Flammability classificationRefrigerants are divided into three groups according to flammability: 

Class 1 indicates refrigerants that do not show flame propagation when tested in air at 21°C and 101 kPa;

Class 2 indicates refrigerants having a lower flammability limit of more than 0.10 kg/m3 at 21°C and 101 kPa and a heat of combustion of less than 19 kJ/kg;

Class 3 indicates refrigerants that are highly flammable as defined by a lower flammability limit of less than or equal to 0.10 kg/m3 at 21°C and 101 kPa or a heat of combustion greater than or equal to 19 kJ/kg.

c.) Mixtures

Mixtures, whether zeotropic or azeotropic, with flammability and/or toxicity characteristics which may change as the composition changes during fractionation, shall be assigned a safety group classification based on the worst case of fractionation.e.g. R404A is classified A1

Desirable properties of a good refrigerant

a.) Thermodynamics:1. Boiling point : Boiling point should be less at NTP, otherwise vacuum on low pressure side.

2. Freezing point: Freezing point should be evaporator temperature.

3. Evaporating Pressure: Evaporating Pressure should be slightly above atmosphere pressure at required evaporator temperature to avoid leakage.

4. Condensing pressure: Condensing pressure should be low to avoid robust construction.

5. Latent heat of vaporization: Latent heat of vaporization should be high, since evaporation of reference refrigerating effect. So, high latent heat reduces mass of refrigerant.

6. Critical temperature and pressure: above condensing temperature, for easy condensation of vapour.

In order to have large range of energy transfer (isothermal) else, there would be excessive power consumption.

7. Compression Ratio: Compression Ratio should be as small as possible otherwise leakage of refrigerants occurs.

8. Coefficient of performance: Coefficient of performance gives running cost so COP increases cost decreases.

9. Conductivity: Conductivity should be very large so size of condenser and evaporator is small.

10. Specific heat: Specific heat should be as small as possible.

b.) Chemical properties:1. Chemical stability and inertness: Refrigerant should stable, not form higher boiling point liquid or solid due to Polymerization.

R-12 decomposes at 550oc

CO2 decomposes at 1000oc

SO2 decomposes at 1650oc

Refrigerant should be inert. It should not react.

2. Action on rubber or plastic: In several places in refrigeration system where rubber and plastic are employed, They should not effected by refrigerant.

3. Flammability: Liquid with flash point under 294.2k are regarded as highly flammable. Best refrigerant co2 and poor ethane.

4. Effect of refrigerant on oil: The refrigerant should not react with the lubricating oil otherwise leads to different lubrication action due to either thickening or thinning of fluid.

5. Effect of refrigerants on commodity: The commodity kept in the conditioned space should not be affected. If the refrigerant is directly used for it’s chilling.

R-12 does not effect the commodity

R-717 spoils the commodity

6. Toxicity: A toxic refrigerant in one which in injurious to human being if subjected to a given span of time.

C.) Physical properties:

1. Smell: A refrigerant having smelling property, so that leakage can be detected.

2. Viscosity: It should be as small as possible, so that the pressure drop in system be small.

3. Dielectrical strength: Important factor for hermetic compressor wherein rotor is subjected to vapour form

evaporator, so insulation should not affected due to refrigerant vapor.

d.) Safety criteria:1. Toxicity

2. Flammability

3. Action on food

4. Formation of explosive compound

e.) Economic criteria:1. Cost of refrigerant

2. Storage and handling

3. Personal preferences

4. Availability and supply

CONTROLLED ATMOSPHERE STORAGE

Controlled atmosphere storage is a system for holding produce in an atmosphere that differs substantially from normal air in respect to CO2 and O2 levels. Controlled atmosphere storage refers to the constant monitoring and adjustment of the CO2 and O2 levels within gas tight stores or containers. The gas mixture will constantly change due to metabolic activity of the respiring fruits and vegetables in the store and leakage of gases through doors and walls. The gases are therefore measured periodically and adjusted to the predetermined level by the introduction of fresh air or nitrogen or passing the store atmosphere through a chemical to remove CO2 .

There are different types of controlled atmosphere storage depending mainly on the method or degree of control of the gases. Some researchers prefer to use the terms ”static controlled atmosphere storage” and “flushed controlled atmosphere storage” to define the two most commonly

used systems. “Static” is where the product generates the atmosphere and “flushed” is where the atmosphere is supplied from a flowing gas stream, which purges the store continuously. Systems may be designed which utilize flushing initially to reduce the O2 content then either injecting CO2 or allowing it to build up through respiration, and then maintenance of this atmosphere by ventilation and scrubbing.

Importance of Controlled Atmosphere

CA storage has been the subject of an enormous number of biochemical, physiological and technological studies, in spite of which it is still not known precisely why it works. The actual effects that varying the levels of O2 and CO2

in the atmosphere have on crops varies with such factors as:

a. The species of crop

b. The cultivars of crop

c. The concentration of the gases in the store

d. The crop temperature

e. The state of maturity of the crop at harvest

f. The degree of ripeness of the climacteric fruit

g. The growing conditions before harvest

h. The presence of ethylene in the store

There are also interactive effects of the two gases, so that the effects of the CO2 and O2 in extending the storage life of a crop may be increased when they are combined. The practical advantages of storage under CA can be summarized as follows:

1. A considerable decrease in respiration rate, with a reduction in climacteric maximum, accompanied by an expansion of both pre-climacteric and post-climacteric periods

2. A reduction in the effect of ethylene on metabolism due to the interaction of O2 with ethylene, with a consequent delay of appearance of senescence symptoms

3. An extension in storage life, which can even be doubled, in as much as the over ripening is delayed

4. The preservation of an excellent firmness of flesh, due to effect of CO2 concentration on the enzymes acting on cellular membranes

5. A high turgidity is achieved, such that fruits are more juicy and crisp

6. A smaller loss of acidity, sugars and vitamin C, so that the nutritional and sensory quality is higher

7. A limited degradation of chlorophyll, with a consequent higher stability of colour.

8. Some physiological alterations, such as chill injuries, spot, decay, browning, water core and scald are prevented, or greatly limited

9. Moulds can be reduced, in particular under low O2, high CO2 atmospheres

10. A longer shelf life in the post storage trading, which can even be trebled thanks to the protraction of the effects on respiration and on the other metabolic activities.

Fruits and Vegetables Storage under CA The storability of fruits and vegetables is strictly related to their respiration rate, which is an expression of metabolic activity. Aerobic respiration requires O2, and results in CO2 and heat release. More than 95% of the energy released is lost as heat. The temperature decrease, in particular if helped by modification of the atmosphere leads to a reduction in respiration rate, and therefore to an increase in storage life in fruits with climacteric respiration. Selection of the most suitable atmosphere depends on cultivars, stage of maturity, environmental and cultivation parameters. No one atmosphere is best for all produce, specific recommendations and cautions must be determined for each crop over the range of storage temperature and periods.

Some examples of CA atmospheres can be seen in Table 1 and 2.

*contents in table 1

1. In avocado, CA reduces chilling injury and delays softening.

2. Pre-cooling is necessary.

3. Kiwi is damaged by high CO2, and low O2. Small amounts of ethylene must be eliminated for a long storage life.

4. Pre-cooling is necessary, also rapid attainment of a Ca is useful.

5. Different varieties behave differently in CA storage; some varieties are susceptible to internal breakdown.

Species Temper. °C

RH (%)

O2(%) CO2(%)

Time

Avocado1 7/12 90 2-3 3- 10 2 months

Cherry2 0 95 3- 10 10- 12 30 days

Kiwi3 0 98 2 4-5 7 months

Nectarine4 -0.5/0 95 2 5 50 days

Species Temper. °C

RH (%)

O2(%) CO2(%)

Time

Peach4 -0.5/0 95 2 4-5 40 days

Plum5 0 95 2 5 45 days

Table 1. Controlled atmosphere conditions for some fruit species (from Gormley, T.R., 1985)

Species Temper. °C

O2 (%) CO2 (%) Time

Asparagus 1-4 10-16 10-14 10-15 daysArtichokes 0- 1 2-4 2-3 20-25 daysBroccoli 0 2-3 5- 10 10 daysCabbage 0 2-3 4-5 3-4 months

Cauliflower 0 3-4 5-7 40-50 daysCucumber 12 1-4 0 20 days

Garlic -1 3 5 7 monthsGreen beans 7 3-4 4-5 10 days

Leeks 0 2-4 5- 10 5 months

Onions 0 1-2 0-1 9 months

Tomatoes 2 3-4 2-3 30-40 days

Table 2. Controlled atmosphere conditions for some vegetable species (from Gormley, T.R., 1985)

Atmosphere Conditioning The reduction of O2 level inside the storage rooms can be biologically achieved by means of fruit respiration, or by O2

burning, or by replacing air by feeding nitrogen. In first case, the reduction in O2 down to a steady state level takes place within 15-25 days, with a slow and progressive decrease thereof. When a non-biological system is used, O2 can be reduced to levels of 6-8% within 24 h and the subsequent lowering to the desired levels for storage can take place via respiration.

The reduction in O2 level can be rapid only if the fruits have reached a temperature lower than 5°C. However, waiting for some days for the fruit to be cooled is better, in order not to cause asphyxia, with browning developing at the surface, or inside the first layers of fruit flesh, or hollows being formed inside the tissues of the core.

Fast cooling, in order to enable the storage room to be rapidly scaled, is only possible by hydrocooling. Otherwise it is essential to transfer the product from room to room.

The fastest reduction in O2 level in the atmosphere is obtained by using nitrogen generators (by now, a widely used system), or by feeding liquid N2 Lowering O2 down to steady state controlled atmosphere levels by means of non-biological techniques is disadvantageous from a financial standpoint, due to the high consumption of fuel or of nitrogen. Nitrogen generators selectively separate air to produce an enriched nitrogen system.

Nitrogen separation from the compressed air supply

Nitrogen generator systems using membrane separators

CA Storage RoomsA gas tight room is an obvious prerequisite for achieving a good controlled atmosphere. Thus it is necessary to make room walls gas -tight. In order to ensure that the walls were gas tight to CA storage they were lined with sheets of galvanized steel. Doors may be mounted on a sliding rail, as pictured to the left. Or, they may be mounted to open vertically on overhead rails, as pictured to the right.

The bottoms and tops of the steel sheets were embedded in mastic (a kind of mortar composed of

finely ground limestone, sand, litherage and linseed oil) and, where sheets abutted on the walls and ceiling, a coating of mastic was also applied. Modern controlled atmospheres stores are made from metal-faced insulated panels (usually polyurethane foam) , which are fitted together with gas tight-patented locking devices. The joints between panels are usually taped with gas tight tape or painted with flexible plastic paint to ensure that they are gas tight. Major areas of the store where leaks can occur are the doors. Having rubber gaskets around the perimeter, which correspond to another rubber gasket around the doorjamb or frame so that when the door is closed the two meet to seal the door, usually seal these.Sealed CA rooms go through many pressure changes during the storage season. There is a danger of damaging the walls or ceiling of the rooms if proper measures are not taken to absorb the pressure changes. Pressure/vacuum relief valve is a simple solution to the problem. With this valve mounted externally to a 4" pipe penetrating one wall of the room, a non-threatening pressure level can be kept in the room. Where there is a pressure difference between the store air and the outside air there can be a difficulty in retaining the store in completely gas tight condition. Stores are therefore fitted with pressure release valves,

but these can make the maintenance of the precise gas level difficult, especially the O2 level in the ultra low O2 store.

Pressure release valve is pictured to the left, expansion bag is pictured to right

An expansion bag may be fitted to the store to overcome this problem of pressure differences. The bags are gas tight and partially inflated and are placed outside the store with the bag inside the store. If the store air volume increases then this will automatically further inflate the bag and when the pressure in the store is reduced then air will flow from the bag to the store. The inlet of the expansion bag should be situated before the cooling coils of the refrigeration unit in order to ensure the air from expansion bag is cooled before being returned to the store. With an increasing need for Ultra-low Oxygen (ULO) storage of fruit, the use of air bags is growing in popularity. The air bag can be used in conjunction with a balance/cascading air line on a series of

CA rooms to help absorb pressure changes without changing the oxygen content of the rooms.

Temperature Control The main way of preserving fruits and vegetables in storage or during long distance transport is by refrigeration, and controlled atmospheres are considered a supplement to increase or enhance the effect of refrigeration. CA storage is only successful when applied at low temperatures. Standard refrigeration units are therefore integral components of CA stores. Temperature control is achieved by having pipes containing a refrigerant inside the store. Ammonia or chlorofluorocarbons are common refrigerants. These pipes pass out of the store; the liquid is cooled and passed over the cooled pipes. All temperature measurement systems depend fundamentally on the quality of the measuring sensor. In commercial practice for CA stores the store temperature is initially reduced to 0 °C for a week or so whatever the subsequent storage temperature will be. Also, CA stores are normally designed to a capacity, which can be filled in 1 day, so fruit are loaded directly into store and cooled the same day.

Humidity Control Most fruits and vegetables, which are kept in CA storage, require a high relative humidity, generally the closer to saturation the better, so long as moisture

does not condense on the crop. The amount of heat absorbed by the cooling coils of the refrigeration unit is related to the temperature of the refrigerant they contain and the surface area of the coils. If the refrigerant temperature is low compared to the store air temperature then water will condense on the evaporator. This removal of moisture from the store air reduces its relative humidity, which results in the stored crop losing moisture by evapo-transpiration. In order to reduce crop desiccation the refrigerant temperature should be kept close to the store air temperature.

A whole range of humidifying devices can also be used to replace the moisture in the air, which has been condensed out on the cooling coils of refrigeration units.These include spinning disc humidifiers where water is forced at high velocity onto a rapidly spinning disc.

A technique, which retains high humidity within the store, is via secondary cooling so that the cooling coils do not come into direct contact with the store air. Ice blank cooling is also a method of secondary cooling where the refrigerant pipes are immersed in a tank of water so that the water is frozen. The ice is then used to cool water and the water is converted to a fine mist, which is used to cool and humidify the store air.

Gas Control The atmosphere in a modern CA store is constantly analysed for CO2 and O2 levels using an infrared gas analyser to measure the gas content in the store constantly. They need to be calibrated with mixtures of known volume of gases.

Portable dual gas analyzer capable of measuring oxygen (0-25%) and carbon dioxide (0- 10%) and ethylene analyzer.

There are also ethylene analyzers that continuously measure ethylene concentration in the store. In storage rooms where low ethylene is essential, checks can be made that the ventilation and ethylene removal systems are operating correctly. The minimum resolution of 0.2 ppm makes this instrument very useful for most products and for theultra ethylene sensitive products such as Kiwi Fruit, a reading on this machine will indicate severe storage atmosphere problems.

There are many gas control systems in CA rooms. Carbon dioxide and oxygen sensors are located in the store atmosphere, and send a low voltage signal back to the controller which may be mounted outside the store. This eliminates the need for sample tubing or pumps, and gives continuous real time readings. Gas control systems can extend from 6 to 62 rooms. It

provides individual settings in each room, for any gas and temperature storage regime.

Gas control systems

Two miniature display/controllers, one each for oxygen and carbon dioxide, make up the CA store controller. It features the following control functions: control output for store ventilation when oxygen is low; control output for nitrogen purge when oxygen is high, or if selected, when carbon dioxide is high; control output for scrubbers when carbon dioxide is high; and an optional control output for adding CO2 when carbon dioxide is low.

Scrubbers The composition of the gas mixture inside the storage rooms undergoes continuous change as a function of the metabolic

activity of the stored product and scrubbers are necessary to absorb excess CO2 . Scrubbers are generally classified according to the absorbent material: Ca(OH)2 , NaOH, H2O, zeolites, activated charcoals. They are classified according to the mode of absorption (i.e. chemical or physical), or to the mode of air passage through the absorbing agent. Scrubbers using activated charcoal are currently the most popular. Gas removal with this type of equipment is based on the fixing of CO2 in a particular way, and releasing it again on contact with atmospheric air, even at room temperature.

Scrubbers use advanced electronic PLC control and a panel mounted Carbon Dioxide Analyzer to constantly monitor the status of the carbon beds. Through careful monitoring of CO2

levels, the scrubber switches cycles only when needed, keeping the cycles to a minimum and efficiency to a maximum. By filtering in the scrub air and the fresh purge air, carbon life is also kept to a maximum.

Carbon dioxide and Oxygen Damage CA storage have also adverse effects, at O2 levels below 1%, in the absence of CO2 , anaerobic conditions can prevail with the consequent formation of alcohol and physiological changes.

Also high CO2 and low O2 may cause abnormality in metabolism. The level of CO2, which can cause damage to fruit and vegetables, varies between cultivars of the same crop.

Variability in plant material prevents precise controlof intercellular atmosphere; recommendations can be designed only to avoid complete anaerobic conditions and a harmful level of CO2 in the centre of the permeable individual fruit and vegetable.

Some examples of CA injury can be seen in Table 3.

Scrubber:

The unit consists of an activated carbon filter chamber, a low -pressure ventilator, an air-transport system, a control unit, and a buffer or lung system.

Crop and

cultivars

CO2 injury level

CO2 injury symptoms

O2 injury level

O2 injury symptom

sApple,

red delicious

>3% Internal browning

<1% Alcoholic taste

Apple, Fuji >5% CO2 injury <2% Alcoholic taint

Apple, Gala >1.5% CO2 injury <1.5% Ribbon scaldApricot >5% Loss of

flavour<1% Off-flavour

Banana >7% Green fruit softening

<1% Brown skin, discoloration

Cabbage >10% Discoloration of inner leaves

<25% Off-flavour

Green beans

>7% Off-flavour <55% Off-flavour

Cherry >30% Brown, discoloration

<1% Skin pitting, Off-flavour

Mango >10% softening <2% Skin discoloration

Table 3. Examples of CA injury (from Thompson A.K, 1998)

CA DEVELOPMENT

The direction suggested by studies carried out in the past as to the most suitable gas composition has change progressively on the basis of the new experiences gained, on the development of new support equipment, and of new structural technologies. From atmospheres where O2 and CO2, generated by fruit respiration, were in equilibrium (O2 11- 16%; CO2 5- 10%), the studies have progressively turned to atmospheres with limited concentrations of O2 and CO2, accomplished by means of air cleaners (O2 2-3%; CO2 2-5%). More recently, lower O2 and CO2 levels (respectively 1- 1.5% and 0-1%) were investigated.

This concept of the progressive reduction of O2 and CO2 in the atmosphere, in order to limit the respiratory activity and thus more or less extend the storage life of the product, led to the adoption of the so-called ULO (Ultra low oxygen) system. The advantages of ULO are particularly evident when the temperature and O2 concentration are simultaneously quickly reduced in the atmosphere inside the storage rooms. This is called RCA, rapid controlled atmosphere. High CO2 treatment (10-15% for 10- 15 days) and initial O2 stress have also been proposed to enhance the effects of CA storage.

Further developmental proposals for CA modification are dynamics CAs, in which O2 and CO2 levels are changed during storage according to previously programmed patterns, or as a function of physiological parameters of stored fruit, or with an intermittent enrichment with high-dosage CO2

for a few days.

CA TRANSPORT

A large and increasing amount of fresh fruit and vegetables is transported by sea freight (reefer) containers. Controlling the levels of some of the gases in reefer containers has been used for many years to increase the marketable life of fresh produce. CA containers have some mechanism for measuring the changes in gases and adjusting them to a pre-set level. The degree of control over the gases in container is affected by how gas tight the container is, some early systems had a leakage rate of 5m3 /h or more, but current systems can be below 1m3 . The systems used to generate the atmosphere in the containers falls into three categories:

1. The gases that are required to control the atmosphere are carried with the container in either a liquid or solid form

2. Membrane technology is used to generate the gases by separation

3. The gases are generated in the container and recycled with pressure absorption technology and swing absorption technology

The first method involves injecting nitrogen into the container to reduce the level of O2with often some enhancement of CO2.The gases are carried in the compressed liquid form in steel cylinders at the front of the container, with access from the outside.

In containers, which use membrane technology, the CO2 is generated by the respiration of the crop and nitrogen is injected to reduce the O2 level. The nitrogen is produced by passing the air through fine porous tubes, made from polyamides, at a pressure of about 5-6 bar. These will divert most of the oxygen through the tube walls leaving mainly nitrogen, which is injected, into the store.

The containers use ventilation to control O2 levels and a patented molecular sieve to control CO2 . The molecular sieve will also absorb ethylene and has two distinct circuits which are switched at predetermined intervals so that while one circuit is absorbing, the other is being generated. The regeneration of the molecular sieve beds can be achieved when they are warmed to 100 °C to drive off the CO2 and ethylene. This system of regeneration is referred to as temperature swing where the gases are absorbed at low temperature and released at high temperature. Regeneration can also be achieved by reducing the pressure around the molecular sieve, which is called pressure swing. A computer controls all the level of gas, temperature and humidity within the container, which is an integral part of the container. It monitors the levels of oxygen from a paramagnetic analyser and the CO2 from an infrared gas analyser and adjusts the levels to those, which have been preset in the computer.

REFERENCES

Thompson, A.K. 1998. Controlled Atmosphere Storage of Fruit and Vegetables, CAB International, UK.

Gormley, T.R., 1985, Chilled Foods, the State of the Art, Elsevier App. Sc i. , London, New York.

Proudlove R.K, 1989, The Science and Technology of Foods, Forbes Publications, England.

Storage Control Systems Inc. Web page, www.storagecontrol.com