Introduction to the working principle of adsorption dryer

　　The adsorption dryer uses advanced chemical technology. The principle is to use the saturated compressed air to use the difference between the moisture and the air molecule volume. The special molecular sieve for gas purification is used to filter the saturated water vapor in the compressed air, which can easily remove the water molecules. Adsorbed in molecular sieve particles, and then using regeneration method to reduce molecular sieve, the compressed air dew point can easily reach -40 ℃.

　　According to the method of adsorbent regeneration, it can be divided into two types: non-heat regeneration micro-heat regeneration suction dryer and thermal regeneration micro-heat regeneration suction dryer. Since the non-thermal micro-heat regeneration suction dryer works according to isothermal adsorption, it is also called "pressure swing adsorption". The thermal micro-heat regeneration suction dryer works according to isobaric adsorption, also known as "temperature swing adsorption". In actual use, there is also a kind of micro-heat dryer. From a formal point of view, the micro-heat regeneration dryer also heats the regeneration gas, but because it uses the regeneration gas from its own low water content drying Air, so it is also a "pressure swing adsorption" dryer.
　　Adsorption dryers are more commonly used to bypass the hot gas to the middle of the evaporator or before the evaporator, which is equivalent to providing a dummy load for the evaporator by the hot gas. Although the actual load is low, the thermal expansion valve can still supply the evaporator. Provide more refrigerant liquid, so as to ensure that there is enough refrigerant flow rate in the evaporator, and will not cause difficulty in returning oil to the evaporator.
　　When a liquid separator is installed in front of the evaporator or multiple evaporating copper pipes in parallel, it is very inconvenient to directly bypass the hot gas to the middle of the evaporator, so the method of bypassing the hot gas to the evaporator is generally adopted.
　　Since the pressure of the evaporator of this kind of adsorption dryer will be relatively large, in order to get along with the influence of the pressure drop of the evaporator, it is necessary to use an energy valve with a pressure pipe. The external balance pressure pipe leads from the compressor suction pipe to control the pressure, and the opening of the valve is controlled only by suction and not by the pressure behind the valve. The bypass position is selected between the outlet of the thermal expansion valve and the inlet of the liquid separator. In order to prevent the backlash of hot gas on the thermal expansion valve and affect the normal operation of the thermal expansion valve, a special gas-liquid mixing head must be used.