Metal/air fuel cell with electrolyte flow equalization manifold

Abstract

A manifold system is described for equalizing electrolyte flow to a plurality of metal/air cells of a fuel cell assembly. The fuel cell comprises: (a) a housing, (b) a plurality of metal/air cells disposed vertically in the housing, (c) air injection means for flowing oxidizing air between the metal/air cells, (d) an electrolyte storage tank, (e) a recirculation loop for continuously recirculating electrolyte from the storage tank through the metal/air cells, (f) an electrolyte inlet manifold forming part of said recirculation loop, said manifold comprising a large manifold tube extending horizontally beneath a plurality of said metal/air cells and a plurality of small feeder tubes extending horizontally, laterally from said large tube, each small feeder tube extending across beneath a single metal/air cell and flow connecting to the bottom of the cell, said large tube having a diameter sufficiently greater than the diameter of the small feeder tubes such that the total combined flow of all of the small feeder tubes does not cause a significant pressure drop in the large manifold tube. Each feeder tube has a length and diemeter to provide a friction pressure drop therethrough which is sufficiently high that the static pressure head difference due to elevation at the cell inlet between the lowest and highest cells in an inclined stack is very small compared to the pressure drop across each individual small feeder tube.