Main parts of refrigerated dryer (abbreviated as cold dryer)

① At present, most refrigeration compressors used in compressor dryers use medium to high temperature fully sealed reciprocating compressors, which are characterized by compact structure, small volume, light weight, low vibration, low noise, and high energy efficiency ratio. Due to the fact that the motor and main body of the fully sealed compressor are sealed in a steel shell, the motor operates in a refrigerant gas environment with good cooling conditions and a longer lifespan. There is a specified amount of lubricating oil stored in the lower part of the casing, which automatically supplies oil to each part when the compressor is working, and there is no need to add lubricating oil in normal times. In large refrigeration and drying machines, semi sealed reciprocating machines or screw compressors are also selected, which are characterized by high refrigeration power and can be adjusted for load to meet different needs.

② Heat exchange, evaporator

The main function of heat exchange in a refrigeration dryer is to utilize the cooling capacity carried by the compressed air cooled by the evaporator (which is considered waste cooling for the vast majority of users) and use this cooling capacity to cool the compressed air carrying a large amount of water vapor at higher temperatures, thereby reducing the heat load on the refrigeration system of the refrigeration dryer and achieving the goal of energy conservation. On the other hand, the temperature of low-temperature compressed air rises in the heat exchanger, preventing condensation on the outer wall of the exhaust pipeline due to low temperature.

The evaporator is the main heat exchange component of a cold dryer, and compressed air is forced to cool in the evaporator. Most of the water vapor is cooled and condensed into liquid water, which is discharged from the machine, thereby drying the compressed air. In the evaporator, there is a convective heat and mass exchange between air and low-pressure refrigerant vapor. The low-pressure refrigerant liquid after passing through the throttling device undergoes a phase change in the evaporator to become low-pressure refrigerant vapor, which absorbs surrounding heat during the phase change process, thereby cooling the compressed air.

In order to achieve as high a heat transfer effect as possible, it is necessary to increase the heat release coefficient, that is, to add the heat exchange area of the heat exchanger. Therefore, the outer walls of the copper tubes of the evaporator and heat exchanger of the cold drying machine are equipped with aluminum fins. At the same time, the fins on the copper tube of the heat exchanger can reduce the impact of air on the copper tube and avoid the rupture of the copper tube.

③ Condenser, secondary condenser (pre cooled reheater)

The function of the condenser in the refrigeration dryer is to cool the high-pressure and overheated refrigerant vapor discharged by the refrigerant compressor into a liquid refrigerant, enabling the refrigeration process to continue continuously. Due to the fact that the heat emitted by the condenser includes the heat absorbed by the refrigerant from the evaporator and the heat converted from compression work. So the load of the condenser is greater than that of the evaporator, and there are two types of condensers in the refrigeration dryer: air-cooled (air-cooled condenser) and water-cooled (water-cooled condenser).

The secondary condenser (pre cooled reheater) has the same function as the heat exchanger on the machine, but the difference is that the heat exchanger mainly exchanges heat between high-temperature and low-temperature compressed air, while the secondary condenser mainly uses low-temperature compressed air to cool the high-pressure part of the refrigeration system, allowing the refrigerant to achieve sufficient cooling, thereby improving the refrigeration efficiency of the machine, and avoiding high-pressure tripping or machine failures caused by poor heat dissipation of the machine condenser.

④ Cyclone separator (gas water separator)

Cyclone separators are also an inertial separator commonly used for gas-solid separation. Compressed air enters along the tangential direction of the cylinder wall