The core of a membrane dryer lies in the use of polymer membrane materials with special properties. This membrane material has selective permeability to different gas molecules, for example, water vapor molecules can pass through the membrane pores quickly, while other gas molecules such as nitrogen and oxygen are effectively blocked. When moist compressed air flows through the membrane module, based on the selective effect of the membrane, water molecules preferentially pass through the membrane wall due to factors such as smaller molecular size, and diffuse from the side with higher partial pressure (compressed air side) to the side with lower partial pressure.

Pressure driven separation: In practical operation, a certain pressure difference needs to be maintained on both sides of the membrane. High pressure and high humidity compressed air enters the interior of the membrane fibers and flows, with water vapor as the "fast gas" easily penetrating to the outer surface of the membrane fibers, while "slow gases" such as nitrogen and oxygen remain inside the membrane fibers. In this way, the moisture is separated and discharged into the environment through the muffler with the backflow airflow, resulting in dry compressed air output.

Continuous drying process: After drying, the compressed air is partially split and blown in the opposite direction to the outer surface of the membrane fiber after decompression and expansion, forming a low-pressure, extremely dry environment. This continuously creates a water pressure difference between the inner and outer surfaces of the membrane fibers, allowing water vapor to continuously penetrate the outer surface of the membrane fibers and be carried away, thereby achieving a continuous and stable drying effect.

Precautions for using membrane dryer:

1. Quality requirements for compressed air

-No liquid condensate: Compressed air should not contain liquid condensate, otherwise it may damage the membrane components or affect the drying effect. Therefore, the compressed air should be thoroughly dehydrated before use.

-Low oil content: The oil content in compressed air must be strictly controlled, generally requiring less than 0.01mg/m?. Excessive oil stains can adhere to the surface of the membrane, reducing its permeability and separation efficiency, and shortening its service life.

-Less particle impurities: There should be no particle impurities larger than 1 μ m in the air, as these impurities may clog the membrane pores, causing damage and failure of the membrane. So, it is necessary to equip with high-grade reliable filters to ensure the quality of compressed air.

2. Operating standards

-Avoid long-term operation without load: Running without load for a long time will cause unnecessary damage to the equipment, reduce its service life, and also waste energy. Therefore, this situation should be avoided as much as possible.

-Cold medium compressor start stop limit: Do not start the cold medium compressor continuously, and the number of starts and stops per hour should not exceed 6 times to prevent compressor overheating and damage.

-Follow the startup and shutdown sequence: When starting up, let the dryer run for 3-5 minutes before turning on the air compressor or inlet valve; When shutting down, first turn off the air compressor or outlet valve, and then turn off the dryer to ensure the normal operation and service life of the equipment.

-Close the bypass valve: There are bypass valves in the pipeline network that are connected to the inlet and outlet of the dryer. During operation, the bypass valve must be tightly closed to prevent untreated air from entering the downstream air pipe network, which can affect air quality and equipment performance.

3. Environmental condition control

-Air pressure limit: The air pressure should not exceed 0.95Mpa. Excessive pressure may cause equipment leakage, damage, or other safety issues.

-Inlet air temperature limit: The inlet air temperature should not exceed 45 degrees Celsius. Excessive temperature may affect the performance and lifespan of the membrane, and even cause safety accidents.

-Stable cooling water supply: If the equipment is equipped with a cooling water system, it is necessary to ensure a stable supply of cooling water and good water quality to ensure the normal heat dissipation and operation of the equipment.

4. Daily maintenance and upkeep

-Regular cleaning: Regularly clean the membrane dryer, including removing internal dust, dirt, and impurities, to maintain the cleanliness and hygiene of the equipment. Especially for the membrane components, they should be cleaned and maintained according to the prescribed methods to extend the service life of the membrane.

-Check component wear: Regularly inspect various components of the equipment, such as fans, motors, valves, pipelines, etc., to see if there is wear, looseness, or other abnormal conditions. Timely identify and replace severely worn components to ensure the normal operation of the equipment.

-Calibration instruments: Regularly calibrate instruments and equipment related to measurement, such as weighing scales, temperature sensors, humidity sensors, etc., to ensure the accuracy of measurement data.