As we all know, the length and inner diameter of a capillary tube are related to the efficiency of the entire machine. The choice of capillary length determines the refrigeration capacity. Different brands and modelsHigh and low temperature damp heat test chamberCan the original capillary tube be used for repair without replacing it, as the length and inner diameter of the capillary tube are different? The answer is affirmative. Below are the specific operational steps.

　　

1、 First, we need to find the outlet position of the capillary tube

　　

The outlet position of the capillary tube in the high and low temperature wet heat test chamber is generally located in the foam layer at the middle and upper part of the back of the box. When replacing the evaporator of the high and low temperature humid heat test chamber, it is necessary to excavate the insulation material on the back and embed the connecting pipe and return pipe of the test chamber. When excavating the insulation layer, it is necessary to dig up along the return pipe until the outlet of the capillary tube is reached. The original capillary tube is usually installed in the return pipe. There must be two pipes with a diameter of 6 or 8 at the outlet of the capillary tube. Weld the capillary tube from the original evaporator inlet, connect it to the inlet of the new evaporator, and then foam and restore it using conventional methods.

　　

For the leakage inside the evaporatorHigh and low temperature damp heat test chamberDon't rush to replace the evaporator (coil) yet. If it is a minor leak, after restoring each pipeline, inject a small amount of refrigerant, start the compressor and work for more than ten minutes, carefully observe the location where frost first forms in the freezer, and mark it properly. If the leakage is fast, you can find a test box of the same brand and model, observe the location where the frost first appears when powered on, and then determine the outlet position according to that location, because the layout of the internal pipes of the test box of the same brand will not have too many differences. In the area where frost first forms, use a craft knife to gently cut a "7" shaped opening, remove the outlet of the capillary tube, and connect it to the inlet of the new evaporator. For the cut, use double tube glue to stick it firmly.

　　

2、 Using the original compressor to reverse blow and flush the capillary tube

　　

The refrigeration equipment processed by this method does not need to adjust the length of the capillary tube as long as it is unobstructed. Due to the strict calculation and testing of the length and inner diameter of the original capillary tube, both of which are in the * state, the testing time can be shortened and the waste of refrigerant in the high and low temperature wet heat test chamber can be reduced. However, it should be noted that the capillary tube must be unobstructed, otherwise it needs to be purged with air pressure.

　　

Weld the capillary tube back to the filter (inlet to outlet, outlet to inlet), open the low-pressure end of the compressor, start the compressor, and use compressed air to blow it in the opposite direction. For severely clogged capillaries, a gas welding gun can be used to heat them, burn the dirt, and then use air pressure to discharge them. If conditions permit, nitrogen can be used for reverse blowing, and then about 100ml of nitrogen tetrachloride can be injected for washing, which will achieve better results.

　　

The purpose of blowing and flushing in the opposite direction of the capillary tube is because dirt is usually not far from the entrance of the capillary tube. IfHigh and low temperature damp heat test chamberBlowing and flushing in the direction of refrigerant flow will blow dirt (impurities) into the middle of the capillary tube, causing the impurities to get tighter and harder to remove.