2-Stage NH3 Refrigeration System for the Operation of Seven Ham Freezers and an Associated Maturation Cold Store
In the food industry, a continuous and reliable refrigeration supply is of utmost importance. The cold chain must not be interrupted during production, storage, further processing, transportation, and until the product reaches the end consumer.
Only in this way can the longest possible protection against spoilage be ensured. ARCTOS, as a competent and reliable partner, provides the necessary technologies and has a wide range of meat and dairy processing companies in its customer reference list.
Requirements
A refrigeration system was planned, built, and commissioned for a new logistics and maturation warehouse for smoked and air-dried raw ham. The task was to cool an automated shelf storage system to +5° C and to freeze the products in the integrated cooling cells from +5° C to -6° C to -14° C.
The freezing of the ham is intended for subsequent further processing. By combining the warehouse, with several thousand pallet positions, and production in one building, transport routes are minimized, and significant cost savings are achieved.
The ARCTOS refrigeration system meets the varying refrigeration requirements of the different areas within the slicing and logistics center.
WHY AMMONIA AS A REFRIGERANT?
The natural refrigerant NH3 is listed under the refrigeration technical designation R717. It is synthetically produced and is a pressurized liquefied gas with a pungent odor.
The fact that R717 has no ozone depletion potential (ODP=0), no direct greenhouse effect (GWP=0), and high energy efficiency makes it an ecologically optimal refrigerant.
| Refrigerant: | NH3 (R717) |
|---|---|
| Refrigerant quantity: | 2,850 kg |
| Cooling medium: | Air |
| Maximum allowable operating pressure: | 13.0/16.0/22.0 bar (Low Pressure/Medium Pressure/High Pressure) |
| Evaporator capacity Q0: | 14 x 40 kW |
| R717 evaporation temperature: | -33° C |
| Air outlet temperature: | -29.5° C |
| Evaporator capacity Q0: | 4 x 50 kW, 1 x 10 kW |
| R717 evaporation temperature: | -8° C |
| Room temperature: | 5 – 7° C |
| R717 condensation temperature: | +35° C |
| Cooling medium: | Air (evaporative condenser) |
| Compressor type (Low Pressure): | 2 Sabroe piston compressors |
| Compressor type (High Pressure): | 2 Sabroe piston compressors |
R717 is economically interesting due to its very high specific evaporation enthalpy. The relatively small amount of refrigerant required and the fact that it is an inexpensive refrigerant reduce operating and energy costs for the operator.
Ammonia is mildly flammable and hard to ignite. The optimal range for its use as an evaporating refrigerant extends from -45°C to +10°C in the cooling range and from +50°C to +80°C in the heat pump range.
Leaked refrigerant is quickly detected due to its characteristic pungent odor, even at very low, non-harmful concentrations. Because of this high warning effect, the disadvantage of NH3—its toxicity—should not be a disqualifying factor for its use in refrigeration systems.
ARCTOS has already built and commissioned a number of NH3 refrigeration systems. Together with you, we make an environmentally important contribution with every new system where you choose R717.