压缩空气在蒸发器中冷却时，有大量凝结水析出。如果冷媒蒸发温度过低，使蒸发器铜管表面温度在负荷条件下低于水的冰点，则凝结水就会在蒸发器里结冰，严重时阻塞气流通道，使供气管道瘫痪。为了防止这种情况出现，必须对冷媒蒸发温度加以控制。其简单有效的措施就是在冷凝器和蒸发器之间加设一只热气旁路阀
压缩空气在蒸发器中冷却时，有大量凝结水析出。如果冷媒蒸发温度过低，使蒸发器铜管表面温度在负荷条件下低于水的冰点，则凝结水就会在蒸发器里结冰，严重时阻塞气流通道，使供气管道瘫痪。为了防止这种情况出现，必须对冷媒蒸发温度加以控制。其简单有效的措施就是在冷凝器和蒸发器之间加设一只热气旁路阀。热气旁路阀的测压管与蒸发压力直接连接，当蒸发压力低到一定程序时，热气旁路阀开启，冷凝器中的高温冷媒蒸气直接进入蒸发器，提升蒸发温度，避免冰堵现象。
Compressed air cooling in the evaporator, there are a lot of water precipitation. If the refrigerant evaporation temperature is too low, the evaporator brass surface temperature under load conditions below the freezing point of water, the water will freeze in the evaporator, serious when blocking flow channel, make the gas supply pipe. In order to prevent the problem, refrigerant evaporation temperature must be under control. Its simple and effective measure is to set up between the condenser and evaporator a hot gas bypass valve. Hot gas bypass valve works directly with evaporating pressure connection, when the evaporating pressure low to a certain application, hot gas bypass valve open, high temperature of the refrigerant vapor condenser directly into the evaporator, promote evaporation temperature, avoid ice blocking phenomenon.
由于蒸发温度降低往往是由冷干机负荷过低造成的，而冷凝器中的高压蒸气总是在压缩机全负荷状态时压出的，所以使用热气旁路阀虽然能在一定范围内防止蒸发温度过低带来的麻烦，但不是节能之举。在大型冷干机中往往采用压缩机卸荷或变频调速等办法来限制蒸发温度过低。
Due to the evaporation temperature decrease is often caused by a low person load, and the high pressure steam in the condenser is always in full load condition of compressor, so the use of hot gas bypass valve can prevent evaporation temperature within a certain scope the trouble too low but not energy-saving. Often used in large person compressor unloading or frequency control of motor speed and so on ways to limit evaporation temperature is too low.
