Find out about the cost-effieciency of ammonia refrigeration for food processing plants

By Simon Burkel, Dec 10, 2013, 13:08 3 minute reading

Of all the refrigerants ammonia is one most efficient. Offering high performance in terms of economic efficiency and environmental friendliness it has been the chosen refrigerant in the industrial refrigeration sector for over a century. Two examples of its use at a Dutch biscuit manufacturer and a German meat processing plant demonstrate the successful, cost-efficient and future-oriented use of ammonia in the food industry.

The economic and ecological advantages offered by NH3 based refrigeration systems are evidenced in two examples below.
Ammonia liquid chiller replaces HFCs at Dutch biscuit plant
The Dutch biscuit and chocolate manufacturer Verkade (United Biscuits) in Zaandam was looking for a new refrigeration system to replace the existing R22 plant. Due to increased production and the introduction of a new type of biscuit, the existing refrigeration system was permanently brought to its capacity limits. What is more, to maintain the required temperatures additional refrigeration capacity had to be hired at great expense particularly during the summer months
GEA Grasso offered a suitable new refrigeration system with a rated capacity of about 1,000 kW. The liquid chilling unit works with ammonia and offers the advantage of being a highly compact system. The systems small footprint measures just 5m x 1m, and it has a height of 2.1m. To maintain product quality, the new system has to guarantee temperatures of about 18°C, and never exceeding 22°C, in the production and storage facilities. 
Verkade’s investment in the ammonia chiller saves them the great expense of hiring additional refrigeration capacity, as the new system efficiently keeps biscuits and chocolate at the required temperature even during the heat of summer.
High energy efficiency ratio of 5.0
The installed refrigeration system is not only environmentally friendly but also offers convincing performance with a particularly high energy efficiency ratio (EER) of 5.0 under full load. The EER increases to about 10 under a partial load of 25%. Among other reasons, this results from the frequency converter integrated in the system for demand-related control of the screw compressor speed. 
Ammonia for huge warehouse buildings and extreme temperatures
Another case demonstrating the strengths of ammonia can be found in the family-run company CDS Hackner GmbH located near Nuremberg, which produces and refines natural casings for sausage skins, and is one of Europe's market leaders in the processing of animal by-products from beef, pork, and lamb. In response to the constant increase in demand, the company expanded its refrigeration and storage capacities, investing about €13 million in the 6,000m2 production complex, deep-freeze storage facilities, a fully automated production line and a state-of-the-art refrigeration system. The storage capacity was increased from 15,100 to 26,000 pallet spaces. 
New energy-efficient refrigeration system with ammonia
In order to refrigerate two new deep-freeze warehouses, each with about 20,000m3 at a ceiling height of 12m, a new energy-efficient refrigeration system with ammonia filling of approximately 2,000kg was installed by Johnson controls. The system features:
  • Two speed-regulated Sabroe screw compressors, which cover the necessary refrigeration capacity of 760 kW
  • An economiser, which is integrated in the screw compressor to maximise overall system efficiency
  • Frequency converters, which optimise the output of the drive motors for highly efficient operation in the partial load range.
The new NH3-system provides the cooling and refrigeration demand for two deep-freeze warehouses. Three shock-froster rooms were connected to an existing CO2 refrigeration plant. An industrial NH3 brine liquid chiller supplies refrigeration energy for the natural casing warehouse and various processing rooms. The system is based on two frequency-controlled piston compressors with ammonia separator and plate evaporator. 


By Simon Burkel

Dec 10, 2013, 13:08

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