The thermal compressed air from air compressor passes via K1 and four way valve HK2 (passes from point3 to point2) into the desorption vessel B2 for drying the wet desiccant. Water vapor passes via four way valve HK1 (passes from point2 to point1) and K3 with compressed air into cooler. The compressed air is cooled to required temperature, and the condensate discharges by the auto drain which is installed at the downstream .