Frozen blockage: also known as "ice blockage". The phenomenon of liquid freezing substances (such as ice) obstructing the flow of refrigerant in Freon refrigeration systems. Often occurring in throttling mechanisms. When the moisture content of Freon exceeds the specified standard (such as the moisture content of R12's factory products should be below 0.0025%) and flows through the throttling mechanism, the temperature drops due to throttling and pressure reduction. The water and moisture mixed in a free state, including the water originally dissolved in Freon that precipitates due to the decrease in solubility after cooling, can form ice at the throttling point and partially or completely block the throttling valve hole or capillary pipeline. As a result, the flow rate of Freon in the system sharply decreased, the suction and exhaust pressure decreased, the refrigeration capacity decreased, and even Freon could not pass through, and the refrigeration device could not work properly. The judgment method is to heat the throttle mechanism with fire. If the above phenomenon can be eliminated after heating, it is considered frozen blockage; otherwise, it is considered dirty blockage.

Methods to eliminate freezing blockage:

Remove moisture from Freon and replace the original desiccant or dryer.

To lower the freezing point of water, a small amount of methanol can be added to the system to dissolve it in water. But this is an emergency measure when there is no moisture absorption equipment and cannot be used easily. When too much methanol is added to the system, it can cause changes in the properties of the refrigerant, resulting in a decrease in refrigeration capacity and affecting refrigeration efficiency. It can also cause chemical corrosion, copper plating, or breakdown and burning of the motor winding of the fully enclosed compressor, seriously affecting the normal and safe operation of the system.