PRESSURE SWING ADSORBING METHOD AND ITS DEVICE

摘要

PURPOSE:To enhance the purity of gas obtained as a product by using the gas desorbed at an initial time zone to wash the other adsorption tower in all desorbing processes and thereafter recovering all gases obtained until the final period of the desorbing process is reached or only the gas desorbed in the intermediate period is recovered as the gas product. CONSTITUTION:The air of a raw material is fed through a feeding pipe 1 and N2 is selectively adsorbed on an adsorbent and nonadsorbed gas is discharged to the outside of the system through a disposal pipe 4 of exhaust gas. When an adsorbing process is finished in either one of adsorption towers 3a-3c, it is washed with the gas obtained in the initial period of the desorbing process of the other adsorption tower and the concn. of N2 in the adsorption tower is increased. Thereafter the adsorption tower is shifted to a desorbing process and firstly in the initial period, the gas obtained by decompressing it with a vacuum pump 6 is introduced into a low-purity gas holder 9b and the desorbed gas is introduced into a high-purity gas holder 9a in the intermediate period and recovered as the gas for a product. The gas desorbed in the final period of the desorbing process may be again introduced into the low-purity gas holder 9b.