Briefly on the factors affecting the dew point of the heatless adsorption dryer

The heatless adsorption dryer utilizes the characteristic of adsorbent to selectively adsorb certain components and adsorb the moisture in the compressed air to achieve the purpose of drying. Since the adsorbent will reach saturation equilibrium after being adsorbed for a certain period of time, it is necessary to regenerate it with dry gas to restore the adsorption and drying capacity. The equipment uses double towers to use part of its own dry gas and reduce the pressure to close to atmospheric pressure, as regeneration gas to regenerate it, and switch between the two towers at a fixed switching time to continuously provide dry gas.

So what are the factors that affect the dew point of the heatless adsorption dryer product?
1. Inlet temperature of adsorption tower
The temperature entering the adsorption tower is generally controlled below 45°C, because the compressed gas is saturated air at a certain temperature. Under the same pressure conditions, every time the temperature increases by 5℃, the saturated water content increases by about 30%, which means that the humidity load entering the adsorption tower increases by about 30%. In addition, the adsorption capacity of commonly used adsorbents decreases with the increase of temperature, so , As the temperature of the compressed gas inlet increases, the drying efficiency of the heatless adsorption dryer decreases. When the intake air temperature increases by 5℃, the dew point of the finished gas outlet will increase by 8~10℃. Once the intake air temperature exceeds 65°C, the adsorption capacity of some adsorbents drops sharply, so the intake air temperature at the same pressure should be reduced as much as possible.
　　

2. Oil content of intake air
The adsorbent is susceptible to the influence of compressor lubricating oil. It is commonly known in the industry as "adsorbent oil poisoning". When the adsorbent absorbs oil mist, the adsorption capacity is directly reduced. Therefore, the compressed gas needs to be degreasing when entering the adsorption dryer equipment. For filtration, the filtration accuracy must be above 0.01μm.

3. Inlet pressure
The design of the heatless adsorption dryer is to proportion the adsorbent according to a certain inlet pressure and the water content in the flow. When the pressure drops, the system flow rate increases, and the water content that the heatless adsorption dryer needs to treat increases, resulting in insufficient adsorption time. The dew point of the product gas drops, so it is not easy to keep the system pressure fluctuation range too large, and it should not exceed the design fluctuation range.
　　

4. Air intake flow
After the heatless adsorption dryer is designed and shaped according to a certain intake temperature, pressure and flow rate, the adsorption capacity of the heatless adsorption dryer is a fixed value. Although some manufacturing companies will leave a certain margin when designing, it is not allowed to increase the equipment processing capacity at will Increase the adsorption load of equipment. Excessive equipment adsorbent load will not only affect the dew point of the finished product, increase energy consumption, but also reduce the service life of the adsorbent.