Why Does the Refrigerator Run for a Few Minutes before Turning on the Air Compressor?

In the industrial compressed air system, the standard start-stop sequence is very important. Among them,start freezing dryer and run for 3-5 minutes before turning on the air compressor, this operation is calledprecooling operation, is the key link to ensure system stability and air supply quality.

I. Principle of precooling operation

freezing dryer stable low temperature conditions need to be established in advance (usually the evaporator temperature drops to 2- 4℃) to fully cool the internal heat exchanger, refrigerant pipeline and drainage system. If the air compressor delivers high temperature and high humidity compressed air immediately after starting with load, it will cause frost on the evaporator surface of the dryer, condensate water cannot be discharged in time, and even cause ice blockage or automatic safety stop.

II. Necessity of linkage control

modern compressed air systems are widely usedfreezing dryer linkage control with air compressor: the start signal of the dryer triggers the delay relay to ensure that the air compressor starts after it enters the steady state. This mechanism belongsspecification for start-stop of compressed air systemsthe core requirements have been widely adopted by GB/T 13277.1-2019 compressed air Part 1: Pollutant purification level and SOP of enterprise equipment.

III. Ignore the risk of precooling

• drying efficiency drops sharply and dew point exceeds the standard (> 3℃), affecting precision pneumatic components and spraying process;
• condensate water accumulates in the aftercooler or gas end, inducing equipment corrosion or instrument malfunction;
• frequent start and stop aggravate the load impact of compressor and dryer compressor and shorten the service life.

Thereforeair compressor start processandindustrial gas treatmentcollaborative management of each link is the basic guarantee to realize efficient, clean and reliable gas supply.