Patent ID: 7485386

Claim:
A solid oxide fuel cell generator comprising: (1) stacks of hollow, axially elongated fuel cells, arranged in bundle stacks, each cell having at least one open top above an electrochemically active portion, which can react and operate on feed oxidant gas and feed hydrogen fuel gas to generate electricity; (2) an oxidant inlet plenum supporting oxidant feed tubes; (3) a feed fuel inlet plenum; (4) a combustion chamber for receiving and combusting reacted oxidant/spent fuel gases, located above the electrochemically active portion of the fuel cells and below the oxidant inlet plenum and containing the at least one open top of the fuel cells, said at least one open top being subject to localized burning, where the combustion chamber is defined by the oxidant inlet plenum, and a fuel cell positioning gasket, which gasket allows permeation of spent fuel gas into the combustion chamber; and (5) a fuel recirculation chamber, below the combustion chamber, said fuel recirculation chamber defined at least by the fuel cell positioning gasket; all surrounded by insulation and all within an outer generator enclosure, where the oxidant feed tubes have an open end in the oxidant inlet plenum and which oxidant feed tubes pass through the combustion chamber and into the at least one open fuel cell top within the combustion chamber, where the fuel cell positioning gasket closely gaskets the fuel cells while concurrently controlling the flow rate of the spent fuel gas electrochemically consumed, and controls gas flow into the combustion chamber by providing a pressure drop across the positioning gasket of from about 0.25 inches of water to 2.0 inches of water, where the fuel cell positioning gasket contains alumina and up to 40 wt. % silica and has a flexible laminate structure comprising at least a compliant fibrous mat layer and a flexible, woven layer facing the combustion chamber, where said woven layer is a nickel containing catalytic layer which promotes flameless combustion in the combustion chamber and provides a region where hydrogen fuel combustion would preferably occur, and where said gasket woven layer of the fuel cell positioning gasket protects the at least one open top of the fuel cells from localized burning of hydrogen, and the fuel cell positioning gasket is flexible and complies to accommodate variable cell bundle pitch.