Copper capillary tubes
Copper capillary tubes
In small refrigeration appliances such as household refrigerators, ice scoops, beverage coolers, and in air conditioners and low-power heat pumps, instead of expansion valves, throttle elements are used - copper tubes with a small internal diameter of 0.5 to 3.0 mm commonly known as capillary tubes. Made of copper in the drag processit is a very inexpensive and straightforward design for throttling the flow, thus lowering the pressure and temperature with evaporation of the liquid entering the evaporator. Its disadvantage is its low regulatory capacity and hence the need to carefully adjust its parameters (diameter and length) to the required cooling capacity. It is very important for proper operation of the refrigeration system with copper capillary tube, accurate filling of refrigerant (no reservoir of refrigerant). The correct pressure can be checked with the pressure gauge mounted on the suction and discharge side of the compressor - using the data on the compressor's nameplate. During normal operation of the device, the breaks in its operation should be so selected that when the compressor stops, the whole system, which means the condenser and the evaporator, equalizes the pressure. After this, the compressor starts without back pressure, with a small starting torque. The electric motor of the compressor may be smaller and cheaper. To protect the capillary tube from clogging (with a damp, thickened oil), replace the filter dryer with every depressurization.
