Using refrigerant to exchange heat with compressed air, the temperature of the compressed air is reduced to the dew point temperature within the range of 2-10 ℃. With the continuous development of the refrigerated dryer industry, more and more companies are entering the air compressor industry, and more and more people are favoring the refrigerated dryer industry. At the same time, many companies stand out, and refrigerated dryers are divided into air-cooled and water-cooled types according to the cooling method of the condenser; There are high temperature intake type (below 80 ℃) and normal temperature intake type (around 45 ℃) according to the intake temperature; According to the working pressure, there are ordinary types (0.3-1.0MPa) and medium and high pressure types (above 1.2MPa). In addition, many special specifications of refrigerated dryers can be used to process non air media such as carbon dioxide, hydrogen, natural gas, blast furnace gas, nitrogen, etc.