An air dryer for removing water vapor from compressed air. Air compression concentrates the water vapor, which increases the dew point of the compressed air relative to the free atmosphere and causes condensation inside the pipe. Excessive water in compressed air can cause various operational problems such as freezing of outdoor air ducts, corrosion of piping and equipment, failure of pneumatic process control instruments, and scaling of processes and products. Desiccants are a group of adsorbents that have a strong affinity for water vapor. A good desiccant must have better moisture absorption and a lower regeneration temperature. XINTAO offers a wide range of desiccants with high affinity and physical resistance, such as 3A molecular sieves, 4A molecular sieves and activated alumina, which can effectively remove water.