To obtain dry air stably and at the same time, promote the saving of energy by dehumidifying gas by one of adsorbing cylinders at each of a plurality of units and regenerating an adsorbent by means of the other adsorbing cylinder and further, making the confluence of dry gas flows from the units, with an operation to switch the process between the units.
When the valve body (f) of a switching valve 26 is located at a position as illustrated, compressed air is adsorbed by adsorbent 17 to be dehumidified when the compressed air passes through an adsorbing cylinder 4 and thus a dehumidifying process takes place. After that, a part of the dry air is sent out of a delivery aperture 9 through a check valve 18B and a delivery path 20 of an outlet head 5. The residue of the dry air is supplied to another adsorbing cylinder 3 through a purge chamber 22 and a purge orifice 12 and the adsorbent 17 in the adsorbing cylinder 3 dries and desorbs the moisture adsorbed in the drying process of the preceding stage to perform the regenerating process of the adsorbent 17. A plurality of units of the described function are installed and each of the processes is switched between the units at such timing as deviated by 1/{2 × number of units (n)} cycle.
OTA KOICHI
INOUE HIROYUKI
