Compressed air is widely used and has become the second largest industrial power source; while the refrigerated dryer (hereinafter referred to as the refrigerated dryer) is the equipment used to dry the compressed air. In the compressed air, there are mainly moisture, dust, and oil that need to be removed. The job of the air dryer is to remove moisture.
Most companies do not use refrigerated dryers in order to save costs. As a result, a large amount of water in the compressed air will enter the back end of the gas, which will lead to equipment failure, damage, pipeline corrosion, and increased product defect rate, which will greatly increase the production cost and bring a huge economic burden to the enterprise!
1. Working principle:
The refrigerating machine cools down through the refrigerant, so that the water vapor in the compressed air condenses into droplets, so as to achieve the purpose of reducing the moisture content. The condensed droplets are discharged out of the machine through the automatic drainage system. As long as the ambient temperature of the downstream pipeline of the dryer outlet is not lower than the dew point temperature of the evaporator outlet, there will be no secondary condensation.
2. Refrigeration system
When the refrigeration system of the dryer is working, the compressor sucks the low-temperature and low-pressure refrigerant gas generated by the evaporator into the cylinder. The refrigerant gas is discharged into the condenser, so the compressor plays the role of compressing and transporting the refrigerant. In the condenser, the refrigerant gas of higher temperature and pressure is condensed into a liquid state by heat exchange with the ambient air (or water) of lower temperature. At this time, the liquid refrigerant is depressurized (cooled) by the throttle valve and then enters the evaporator, where it absorbs the heat of the compressed air and evaporates. In this way, the object to be cooled is cooled, and the refrigerant vapor is sucked away by the compressor to start the next cycle. In this way, the refrigerant goes through four processes of compression, condensation, expansion (throttling), and evaporation in the system to complete a The purpose of refrigeration is achieved through continuous refrigeration cycle.
Refrigeration systems are also very common in life. Next, I will take air conditioners as an example to describe the refrigeration cycle of air conditioners, so as to facilitate readers to better understand the refrigeration system of air dryers.
Air conditioner summer refrigeration cycle: the temperature outside is very high in summer, we want to reduce the temperature of the room, so the evaporator (indoor unit) is arranged in the room, and the heat is moved to the outside, so the outside (outdoor unit) is the condenser .
Refrigeration cycle of air conditioner in winter: The air conditioner in winter is still a refrigeration device, but the purpose of use is different. In winter, the temperature is very low, and we want to heat the room, so the "condenser" is placed inside and the "evaporator" is outside. A four-way valve (as shown in Figure A above) is installed in the air conditioner to complete the role switching between the indoor unit and the outdoor unit.
At present, the quality of refrigeration dryers on the market is uneven. For example, the corrosion and leakage of evaporators have always been the number one thorny problem affecting the stable operation of refrigeration dryers, which seriously shortens the service life of refrigeration dryers. Through high-quality refrigerant refrigeration technology, Jaguar Refrigerator can not only make the pressure dew point of compressed air reach 2-10℃, but also use aluminum alloy plate-fin evaporator assembly, which completely solves the problem of evaporator leakage due to corrosion, and the unit volume The internal heat exchange area is 5 to 10 times higher than that of general tubular heat exchangers. Optimizing the structure and saving the user's space, it is the preferred brand of millions of enterprises.
The following matters should be paid attention to when using the refrigerated dryer:
①The flow pressure and temperature of the compressed air should be within the allowable range of the nameplate;
②The installation site should be ventilated and less dusty. There is enough space for heat dissipation and maintenance around the machine and cannot be installed outdoors to avoid rain and direct sunlight;
③The cold dryer is generally allowed to be installed without foundation, but the ground must be leveled;
④ It should be as close to the user point as possible to avoid the pipeline being too long;
⑤There should be no detectable corrosive gas in the surrounding environment, especially not to be in the same room with ammonia refrigeration equipment;
⑥ The filtration precision of the pre-filter of the cold-drying machine should be appropriate, and excessive precision is not necessary for the cold-drying machine;
⑦The inlet and outlet pipes of cooling water should be set up independently, especially the outlet pipes should not be shared with other water cooling equipment, so as to avoid the obstruction of drainage caused by pressure difference;
⑧ Keep the drainage of the automatic drainer unobstructed at all times;
⑨Do not start the dryer continuously;
⑩ The parameter index of the compressed air actually processed by the refrigerating machine, especially when the intake air temperature and working pressure are inconsistent with the rated value, should be corrected according to the "correction coefficient" provided by the sample to avoid overload operation.