J & E Hall presented the new HallScrew compressor rack aimed at the supermarket refrigeration market for the first time at this years IKK exhibition.
Designed for R404a refrigerant, the HSML 3100 HallScrew compressor racks can handle up to five compressors on one oil separator and offer considerable energy savings.
Independent chill and frozen inverter-based systems, with common standby compressor, give the HSML 3100 range high and low temperature options. Isolating valves also allow the central compressor to act as 100 per cent back up for either system.
Other benefits include:
- an economiser with variable speed control delivering superb Coefficient of Performance figures
- variable frequency drive, maintaining accurate control of suction pressure by varying compressor speed
- and a compressor noise level below 80 d(B)A.
The economiser sub-cools the liquid refrigerant to the expansion valves, reducing flash gas and increasing compressor cooling capacity. The use of the economiser with variable speed control achieves a COP* of 2.6 at -10 ºC suction and 45 ºC discharge and 1.18 at -35 ºC/45 ºC (* assuming 10K suction superheat and 0K sub-cooling at condenser).
Combined with variable frequency drive, the sub-cooler remains in operation even at part-load conditions. The energy savings will give a pay back in less than five years. The system also has an oil separator with an oil management system, a dual safety pressure relief valve with three-way changeover valve and is designed and built to EN378 and in accordance with PED.
Oil filters on each system can be replaced without opening the compressors and under most operating conditions the use of an oil cooler is unnecessary.
Refrigeration capacities range from 50 kW to 150 kW at –35°C/45°C and from 135 kW to 440 kW at –10°C/45°C.