The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 1999
Filed:
Dec. 19, 1997
James Brian Mize, Williamsville, NY (US);
Praxair Technology, Inc., Danbury, CT (US);
Abstract
A pressure swing adsorber (PSA) air prepurifier includes at least a first adsorber and a second adsorber and a controller for controlling air feed to the first adsorber and the second adsorber. The invention is a 'realtime' method for controlling cycle times for each adsorber and includes the following steps. During a determined time period, flow is measured to an adsorber that is coupled to an air inlet. An actual totalized flow to the on-line adsorber is accumulated, based upon the measured flow values. During this time, air feed conditions (e.g., temperature, pressure, relative humidity) are monitored and periodically, a maximum totalized flow to the adsorber is calculated, determined, at least in part, based upon the monitored air feed conditions. Periodically, the actual totalized flow value is compared to a current calculated maximum totalized flow value and upon a predetermined relationship therebetween being reached, the on-line adsorber is decoupled from the air inlet and another adsorber is coupled thereto. The method for controlling cycle times for each adsorber also will take into consideration: variations in load demand, purge to feed ratio and upsets which occur on switching of adsorber beds.