Patent ID: 6893708

Claim:
A fuel-cell flowfield plate for use abutting an electrode plate in a fuel cell and in operation conducting reactant to an electrode plate and conducting liquid reaction product from the electrode plate, including first and second reactant channels on the surface thereof, through which channels the reactant flows when the plate is in use, each said channel having an inlet and an outlet; and lands that bound and separate the channels and that in use abut the electrode plate; characterized in that: the plate has a duct interconnecting the first and second channels, the duct having two duct end openings, a first duct end opening located at a position along the length of the first channel between the first-channel inlet and outlet, and a second duct end opening located at a position along the length of the second channel between the second-channel inlet and outlet, whereby the duct provides a fluid passage between the first and second channels, and wherein, in the event of whole or partial blockage of either of said channels by liquid reaction product, a consequent channel-flow velocity differential between the first channel in the vicinity of the first duct end opening and the second channel in the vicinity of the second duct end opening tends to promote fluid flow via the duct from the channel having the lower channel-flow velocity to the channel having the higher channel-flow velocity, thereby tending to eliminate or reduce the blockage.