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:
Aug. 15, 1995
Filed:
Oct. 19, 1993
Henry H Voss, North Vancouver, CA;
David P Wilkinson, North Vancouver, CA;
David S Watkins, Coquitlam, CA;
Ballard Power Systems Inc., North Vancouver, CA;
Abstract
A method and apparatus is provided for removing water accumulated at the cathode of an electrochemical fuel cell incorporating a solid polymer ion exchange membrane. Liquid water accumulated at the cathode can be removed by maintaining a partial pressure of water vapor in the hydrogen-containing gas supply below the saturation pressure of water vapor therein such that water accumulated at the cathode is drawn by a concentration gradient toward the anode across the membrane and is absorbed as water vapor into the hydrogen-containing gas supply between the inlet and the outlet. In one embodiment, the partial pressure of water vapor in the hydrogen-containing gas supply is maintained below the saturation pressure of water vapor therein by imparting a pressure drop between the inlet and the outlet sufficient to draw water accumulated at the cathode toward the anode. In another embodiment, the partial pressure of water vapor at the inlet of the hydrogen-containing gas supply is maintained at less than the saturation pressure of water vapor therein. Liquid water accumulated at the cathode can also be removed by maintaining a partial pressure of water vapor in the oxygen-containing gas supply below the saturation pressure of water vapor therein such that water accumulated at the cathode is drawn by a concentration gradient and is absorbed as water vapor into the oxygen-containing gas supply between the inlet and the outlet. Liquid water accumulated at the cathode can also be removed by absorbing water vapor into both the hydrogen-containing gas supply and the oxygen-containing gas supply.