| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a VPSA process which forms furthermore efficiently oxygen by a process wherein a purge step with oxygen under a low desorption pressure, an overlapped feeding and pressure-equalization step and oxygen formation/adsorption step are included. SOLUTION: A raw material such as air and a product such as oxygen are simultaneously introduced to the feeding side end part of an adsorption floor and the product end part of an adsorption floor, and the pressure of the adsorption floor is partly elevated to an intermediate pressure level. Then, the raw material is added more to the feeding side end part of the adsorption floor and the pressure of the adsorption floor is elevated to a required high adsorption pressure in parallel flow. Furthermore, while the raw material is introduced from the feeding side end part of an adsorption floor, the product is removed from the product end part. Then, the pressures are lowered in parallel and the removed exhaust gas is transferred to another adsorption floor and nitrogen, etc., adsorbed are desorbed by decreasing the pressures in parallel by means of a vacuum pump and gas is exhausted also from the product end part. In addition, after decreasing in pressure and exhausting of gas are performed, oxygen as the purge gas is added to the product end part on the floor and exhausting of gas and overlapped pressure-equalization are performed, and finally, operation of a blower for feeding is started again.</p> |
