The plant mainly consists of two chambers arranged in parallel which are filled with a water-resistant drying agent. When the compressed air containing moisture penetrates the drying agent in the first chamber the compressed air is dried. In parallel to the drying process, regeneration of the drying agent is carried out in the second chamber. This process requires about 15% of the dried air from the first chamber. The regeneration air generated by adsorption is further dried by expansion from operating pressure to atmospheric pressure and desorbs the previously introduced amount of water. The moisture absorbed by the dried air is delivered into the ambient air via a drain valve. The adsorption chambers are impinged alternately at fixed intervals.