1. What does the refrigeration system of the cold dryer consist of?
The refrigeration system of the refrigeration dryer belongs to compression refrigeration and consists of four basic components: refrigeration compressor, condenser, evaporator, and expansion valve.
They are connected in sequence by pipes to form a closed system. The refrigerant continuously circulates in the system, changes state, and exchanges heat with the compressed air and cooling medium.
In the refrigeration system of the refrigeration dryer, the evaporator is a device that transports cold energy. The refrigerant absorbs the heat of the compressed air to achieve the purpose of dehydration and drying. The compressor is the heart and plays the role of sucking, compressing, and transporting refrigerant vapor.
The condenser is a device that releases heat. It transfers the heat absorbed in the evaporator together with the heat converted by the compressor input power to the cooling medium (such as water or air).
The expansion valve/throttle valve throttles and depressurizes the refrigerant, controls and regulates the amount of refrigerant liquid flowing into the evaporator, and divides the system into two parts, the high-pressure side and the low-pressure side. In addition to the above components, the refrigerated dryer also includes energy regulating valves, high and low pressure protectors, automatic drain valves, control systems and other components.
2. Working principle of cold dryer
The cold dryer is a device that uses the working principle of cooling and condensation to dry compressed air. It is mainly composed of three parts: heat exchange system, refrigeration system and electrical control system. The hot, humid and moisture-containing compressed air from the air compressor is first pre-cooled by an air-to-air heat exchanger.
Then the pre-cooled air is further cooled by the refrigerant circulation loop of the cold dryer in the air-to-refrigerant heat exchanger, and heat exchanges with the cold air that has been cooled to the pressure dew point from the evaporator, so that the temperature of the compressed air is further reduce.
Afterwards, the compressed air enters the evaporator and undergoes heat exchange with the refrigerant. The temperature of the compressed air drops to 0℃-8℃. The moisture in the air precipitates at this temperature. The condensed water and oil in the compressed air are condensed through the condenser. The impurities are separated and discharged out of the machine through the automatic drainer.
The dry low-temperature air enters the air exchanger for heat exchange, and is output after the temperature rises, which can effectively prevent condensation in the pipeline. The bypass valve can automatically adjust the throughput of cold coal according to the requirements of load changes. .