Del Monte, a leading international fruit producer and beverages company, has built a new fresh fruit, juice and salad production facility in Dubai. The facility, which covers some 30,000 m2, consists of several air-conditioned production lines, a cold store and a cooling chamber, where 4,500 t of fruit and vegetables – including the sweet Gold Pineapple – ripen each year. The refrigeration for the facility is provided by an indirect ammonia refrigeration system with a refrigerant circuit, which serves to further maximise the high efficiency of this natural refrigerant. The system’s circuit is charged with 4,000 kg of ammonia. The heated gas is condensed at 40°C by an evaporative condenser. Water is used as the coolant for the high-temperature reactor, and glycol for the low-temperature zone. The cooling is provided by two plate heat exchangers. At the high-temperature level there are three single-stage screw compressors made by Grasso, each with a refrigerating capacity of 630 kW and an evaporation temperature of 1°C. This circuit provides water chilled to 6°C, which is used to cool the higher-temperature cold stores, corridors and for the air-conditioning system as well as to pre-cool the glycol coolant for the low-temperature zone, which also uses three single-stage screw compressors made by Grasso. Its evaporation temperature is -16°C

Del Monte Cold Store: Waliking into the cold storage area of the Del Monte Store

and the refrigerating capacity of the compressors is slightly lower, at 600 kW per compressor. The low-temperature level supplies glycol chilled to -10°C to the processing rooms and cold stores. A seventh screw compressor can also be activated in the event of mechanical failure, to ensure that production continues uninterrupted.

Kraft Foods, Bahrain

Kraft Foods is one of the companies that have opted for natural refrigerants. The international food and beverage company, well known for its brands such as Philadelphia cheese, Miracle Whip mayonnaise and Jacobs coffee, has built a new production plant for cheese products and powdered drinks in Bahrain, from where it will supply food retailers throughout the Middle East with Kraft Foods products. Since the operator places great importance on economical and sustainable refrigeration, Johnson Controls installed an ammonia refrigeration system. At the heart of the facility is a machine room with ammonia refrigeration units that chill cold water to a temperature of just 2°C by cooling the ammonia, which has a total refrigerating capacity of 8,000 kW, and evaporates at 0°C. The coolant is distributed to the various users via a network of pipes, where it absorbs the heat generated by the manufacturing processes. Other components of the system include four screw compressors, some of which are speed-regulated, two plate heat exchangers, one gravity-driven separator and three evaporative condensers. The refrigeration plant for the approx. 60,000 m2 production plant was put into operation in late 2007.

Iran Dubai Co., Bushehr

The fruit and vegetable wholesaler Iran Dubai Co. operates numerous cold stores and distribution centres throughout the Middle East. At its site in Bushehr, an Iranian port on the Persian Gulf, the existing warehouse needed to be enlarged and converted into a cold store. For the conversion 33 ammonia evaporators manufactured by Güntner, specially designed for high-pressure operation and no more than 4.5 m long, were used. The reason for this was that the units needed to be fitted on brackets at a specific height on the walls, which meant that the wholesaler was particularly interested in a compact yet high- performance solution. The warehouse, which covers an area of 3,700 m2, consists of several cold storage chambers, each at a different temperature, ranging from -25°C to 0°C up to 15°C The evaporation temperatures thus range from -33°C to 5°C, with a refrigerating capacity of about 50 kW per unit. There is a separate storeroom for bananas that is kept at a temperature of 13.5°C. Here, the evaporation temperature is 7.5°C at a refrigerating capacity of 123 kW. Any parts of the system that are iced up are defrosted using hot ammonia gas.

Panda, Riyadh

Johnson Controls installed a similar solution for the Panda Group of Companies, a Saudi Arabian food retailer which built a state-of-the-art distribution centre in Riyadh that was put into operation in 2008. The refrigeration needed for the different store rooms is generated centrally by a gravity-driven ammonia system that is connected to two refrigerant circuits. One of the circuits provides water chilled to 13°C for cooling the regular storage rooms, while the other provides glycol chilled to -10°C for the chill stores, cold stores and freezers. This system uses module-welded plate heat exchangers made by Alfa Laval. The heat from the evaporated ammonia is transferred to a second glycol circuit, which is used to defrost the freezers.

Dr. Karin Jahn

"Natural refrigerants are not only an energy-efficient alternative," says eurammon’s Georges Hoeterickx. "They are also a convincing solution thanks to their unrivalled environmental friendliness, as natural refrigerants do not destroy the ozone layer and have either no global warming potential, or negligible global warming potential. They are thus especially important in light of global climate-protection targets."