Patent ID: 7094491

Claim:
A fuel cell, comprising a plurality of individual cells formed in a stack, the cells separated by separators, the cells each comprising a fuel electrode on one face of an electrolyte membrane and an oxidant electrode on the other face, and said stack further comprising supply and exhaust inner manifolds for distributing to and receiving from these cells a fuel gas supply, an oxidant and a coolant supply, and exhaust therefrom, respectively, said manifolds having at least one side part, a length and at least one end wall havihg a plane; a cylindrical fuel gas supply port having a perimeter and a central axis, the supply port penetrating one end wall of a fuel gas supply inner manifold such that the fuel gas supply enters the fuel gas supply inner manifold having an average gas supply flow direction parallel to the central axis of the supply port; a side part of the inner manifold faces a gas passage inlet of the separator on the fuel electrode side, cylindrical piercing member having a length, a central axis, a perimeter and an external, volume defined by the length and perimeter, the piercing member extends lengthwise through the stack and pierces through an inner manifold of the stack, including pierces through at least the fuel gas supply inner manifold, wherein the piercing member is positioned between the gas supply port and the gas passage inlet such that the fuel gas supply inner manifold is separated by the piercing member into first and second volumetric regions, each volumetric region having a length and each volumetric region having a volume greater than the external volume of the piercing member, in the plane of the end wall of the fuel gas supply inner manifold penetrated by the supply port, the perimeter of the piercing member and the perimeter of the fuel gas supply port have no overlap, and the central axis of the gas supply port is parallel to the central axis of the piercing member, such that the flow direction of the fuel gas supply entering from the fuel gas supply port into the first volumetric region of the gas supply inner manifold is substantially parallel to the central axis of the piercing member and a fuel gas supply flowing into the first volumetric region of the manifold can transit the length of the first volumetric region of the manifold in a straight path without colliding with the piercing member; a proper gap is interposed between said cylindrical piercing member and an inner wall of the fuel gas supply inner manifold along the length direction of the piercing member; wherein the arrangement directs a flow of fuel gas through the proper gap substantially orthogonal to the flow direction of the fuel gas supply entering from the supply port into the first volumetric region of the gas supply inner manifold and the flow of fuel gas through the gas supply inner manifold from the first volumetric region to the second volumetric region is flow-regulated by the piercing member.