Supermarket commercial refrigerator or freezer will often fault with non-stop and long-term use , and the blockage of the refrigeration system is one of the most common fault to the refrigerated unit. Once the system is blocked, it will cause poor cooling effect and increase power consumption; more seriously ,it will cause the refrigerant can not flow, leading to zero refrigeration effect.

The supermarket refrigeration system of refrigerated unit as shown in the figure, which is composed of a compressor, a condenser, capillaries, evaporator and dry filter. Its working principle is: refrigeration compressor suck up the refrigerant from the evaporator with low temperature and low pressure , and compress the refrigerant into high temperature and high pressure, which has been transported to the condenser and transfer a great amount of heat to the air outside of the refrigerated unit, then high pressure refrigerant with non-high temperature has come into being. The trace moisture and impurities are filtered when they pass the dry filter, and then the refrigerant liquid with high pressure become low pressure wet steam after going  through capillary throttle，which will be evaporated and have the endothermal reaction with a certain air pressure.