Refrigeration air dryer

Abstract

A refrigeration air dryer, which dehumidifies compressed air by cooling the air at a cooler by exchanging heat with a refrigerant, includes a first reheater and a second reheater. The first reheater has a configuration in which warm and moist primary air to be dehumidified is preliminarily cooled by exchanging heat between the primary air and low-temperature dehumidified air dehumidified by the cooler, and is transmitted to the cooler. At the same time, the temperature of the humidified air is raised, and the humidified air is transmitted to the second reheater. The second reheater has a configuration in which the humidified air having a temperature raised by the first reheater is again raised by exchanging heat with the high-temperature refrigerant compressed by the refrigerant compressor, following which the humidified air is externally discharged as secondary air.

1 . A refrigeration air dryer including:
 a refrigerant system including a refrigerant compressor, a condenser which condenses a high-temperature refrigerant compressed by the refrigerant compressor, a decompressing mechanism which decompresses, by adiabatic expansion, the refrigerant which has been condensed by the condenser, so as to lower the temperature thereof, and a cooler which again cools the air, which has been preliminarily cooled by a first reheater in an air system, using the low-temperature refrigerant transmitted from the decompressing mechanism, so as to dehumidify the air, and which is configured such that the refrigerant transmitted from the cooler is returned to the refrigerant compressor; and   the air system including an air inlet which allows warm and moist compressed air, which is to be dehumidified, to be input as primary air, the first reheater which preliminarily cools the primary air and raises the temperature of the dehumidified air by exchanging heat between the primary air input via the air inlet and low-temperature dehumidified air transmitted from the cooler, and the cooler which again cools the primary air thus preliminarily cooled by the first reheater so as to dehumidify the primary air, thereby obtaining the low-temperature dehumidified air,   wherein the refrigeration air dryer further includes a second reheater which exchange heat between the dehumidified air, of which the temperature has been raised at the first reheater by exchanging heat with the primary air, and the high-temperature refrigerant compressed by the refrigerant compressor,   and wherein the dehumidified air, of which the temperature has been again raised by heat exchange at the second reheater, is output as secondary air via an outlet pipe.   
     
     
         2 . A refrigeration air dryer according to  claim 1 , wherein the second reheater is connected between the refrigerant compressor and the condenser,
 and wherein the refrigerant transmitted from the refrigerant compressor is transmitted to the condenser via the second reheater.   
     
     
         3 . A refrigeration air dryer according to  claim 2 , wherein a high-temperature refrigerant pipe connecting the refrigerant compressor and the second reheater and a low-temperature refrigerant pipe connecting the decompressing mechanism and the cooler or a return refrigerant pipe connecting the cooler and the refrigerant compressor are connected so as to communicate with each other via a bypass refrigerant pipe including a volume adjusting valve which provides an adjustable opening, thereby allowing a portion of the high-temperature refrigerant compressed by the refrigerant compressor to directly flow into the low-temperature refrigerant pipe or the return refrigerant pipe in a case in which the load of the cooler has become small. 
     
     
         4 . A refrigeration air dryer according to any one of  claim 1  to  claim 3 , further including a drain separator in a flow channel from the cooler up to the first reheater, which is used to perform drain separation processing for the air again cooled by the cooler.