Patent ID: 7097763

Claim:
An ion exchange filter apparatus for a liquid medium used in a fuel cell system, comprising: an ion exchange filter to receive an ion exchange resin for reducing ions contained in the liquid medium, the ion exchange filter comprising: a flow passage to introduce the liquid medium to the ion exchange resin; a bypass passage to flow the liquid medium by bypassing the ion exchange resin; an orifice disposed at a branch section where the bypass passage is branched from the flow passage, to determine a flow volume ratio of the liquid medium flowing in the ion exchange resin and the bypass passage, wherein: a hole diameter of the orifice is set so that a pressure loss generated when all the amount of the liquid medium flows in the bypass passage becomes substantially equal to an allowance maximum pressure loss of the ion exchange filter; a filter housing; and a filter cartridge exchangeably received in the filter housing, wherein: the filter cartridge includes: the ion exchange resin received in a cartridge casing; an urging spring to urge the ion exchange resin toward an inlet side of the cartridge casing; the flow passage to introduce the liquid medium to the ion exchange resin; the orifice disposed in the branch section from the flow passage to the bypass passage; open mesh disposed in an inlet of the filter cartridge upstream of the ion exchange resin and in a backside of the urging spring downstream of the ion exchange resin, a mesh size of the open mesh being so large as to prevent outflow of the ion exchange resin; and fine mesh disposed in an outlet of the filter cartridge, a mesh size of the fine mesh being smaller than the mesh size of the open mesh.