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:
Jan. 30, 2007
Filed:
Mar. 29, 2004
Russell H Barton, New Westminster, CA;
Michael P Sexsmith, North Vancouver, CA;
Russell H Barton, New Westminster, CA;
Michael P Sexsmith, North Vancouver, CA;
Ballard Power Systems Inc., Burnaby, CA;
Abstract
In a hydrogen gas line where the composition of the gas is primarily hydrogen, impurities present in the gas line will typically reduce the speed of sound. Accordingly, an acoustic sensor can be used in such a hydrogen gas line to indicate when impurities have accumulated in the gas line. In particular, the hydrogen gas line may be in a fuel line for an electrochemical fuel cell system. The sensor may comprise transducers, more particularly piezoelectric transducers, as both sound detectors and/or sound generators. Further, the sensor can measure either the speed or frequency of sound to determine the hydrogen concentration. If the fuel is recirculated back to the anode inlet, such a hydrogen sensor in the anode exhaust may be used to determine when it is beneficial to purge the anode exhaust to the external atmosphere.