A drying device dedicated to pneumatic systems that removes moisture from compressed air and supplies dry, clean air. Types include refrigerated air dryers, adsorption air dryers, and membrane air dryers, selected according to dew point temperature and air flow capacity. Used in moisture-sensitive processes such as painting lines, precision machining, electronic component manufacturing, and food processing to prevent corrosion of pneumatic equipment, improve product quality, and prevent condensation in piping. Installed downstream of air compressors and combined with air filters and air tanks to form air purification systems. Unlike simple air filters or drain separators, this is specialized equipment with active dehumidification functions.