GB1461617A - Refrigeration apparatus - Google Patents

Abstract

1461617 Deep freezers KœLEG KœHLMÍBELFABRIK & APPARATEBAU GmbH 5 April 1974 15281/74 Heading F4H A deep freezer comprises a cabinet 12 divided into a storage space 13 and a space 7 by a partition 4 which is spaced from the top and bottom walls 6, 5 of the cabinet to allow gas to circulate therearound through passageways 20, 19. The refrigeration system for the freezer includes a compressor and condenser unit 10, 11 and an evaporator 8 disposed in the space 7. The freezer also includes a source of liquid refrigerant gas 28, e.g. liquid nitrogen, and a number of perforated pipes 26 connected to the source 28 for the direct admission of the liquid gas into the cabinet for rapid freezing purposes. Excess gas may pass out of the cabinet through discharge pipes 29. One or more motor driven fans 9 are located at the base of the space 7 to draw gas through passageway 19 up through the space 7 over the evaporator 8. Each fan 9 is driven by a motor 14 arranged beneath the fan blades in a housing 15. The housing has an open top and a bottom which slopes towards a central drain aperture 17. The housing acts to thermally insulate the motor 14 for the refrigerant gases passing around the cabinet. In operation of the freezer, goods stored in space 13 on a trolley 22 are frozen initially by gas from cylinder 28. The mechanical refrigeration system is brought into operation after the supply of the liquid gas to the pipes 26 has been shut-off. The fan or fans 9 may be operated during both the initial rapid freezing stage and the subsequent normal refrigeration stage.