Compressed air system is a very important public system in power plant. If there is moisture in the compressed air, it will bring many follow-up problems to the equipment, such as increasing the operation and maintenance costs, reducing the working efficiency of the equipment, affecting the quality of the production process, etc. Therefore, in the compressed air source purification treatment system, water removal is necessary and important. The main application of compressed air in power plant includes: instrument compressed air system, plant miscellaneous compressed air system, water disposal compressed air system and ash removal compressed air system.