Abstract: According to a method of cooling gases, in particular air which is drawn in through a compressor, in a compressed air arrangement the gas flows alternately through at least one of a plurality of refrigerating driers (5, 6) equipped with heat exchangers (15, 16). The gas drawn in is cooled by means of a heat exchanger (15, 16) to below 0.degree. C. over a cooling section. Whilst the gas is being cooled, the ice produced in the refrigerating drier (5, 6) is defrosted by at least one of the refrigerating driers (5, 6) or in the further refrigerating drier(s) (5, 6) by the supply of a hot refrigerant vapour. The liquid refrigerant flowing out of the refrigerating drier (5, 6) to be defrosted is introduced into a pressure and/or connection line (17, 18) of the refrigerant circuit between the inlet of the heat exchanger (15, 16) used for cooling the gas drawn in and the condenser (59), which is arranged upstream of this (these) heat exchangers, or the tank.

Abstract: The invention relates to a method and a device for compression of gases, in particular of air, within a compressed air piping system. The air drawn in for the compressor is cooled below 0.degree. C. within a freeze-dehumidifer in a cooling channel. The supply of undercooled refrigerant into the freeze-dehumidifier is interrupted during the defrosting of the freeze-dehumidifier situated within the cooling channel for the air drawn in towards the compressor. The condensate appearing in the form of ice on the freeze-dehumidifer is separated thereby. The defrosting operation is terminated after a pressure of the refrigerant corresponding to a positive temperature of the freeze-dehumidifier is exceeded, or after a presettable period has elapsed. The pressure of the refrigerant is monitored in the suction pipe and if appropriate in the delivery or pressure pipe of the refrigerant compressor.