Patent ID: 7309537

Claim:
A reactant supply system for a fuel cell system having a fuel cell stack with an inlet stream and an exhaust stream, the reactant supply system comprising: an apparatus for recirculating a reactant fluid stream of the fuel cell system, the apparatus comprising: a common suction chamber fluidly connected to a suction inlet configured to receive a recirculated flow from the exhaust stream of the fuel cell stack; a low-flow nozzle positioned in the common suction chamber and fluidly connected to a low-flow motive inlet configured to receive a first motive flow from a reactant source of the fuel cell stack; a low-flow diffuser fluidly connected to a discharge outlet configured to provide the inlet stream to the fuel cell stack; a high-flow nozzle positioned in the common suction chamber and fluidly connected to a high-flow motive inlet configured to receive the first motive flow from the reactant source; and a high-flow diffuser fluidly connected to the discharge outlet; a regulator, fluidly connected to, and interposed between, the reactant source of the fuel cell stack and the low-flow and high-flow motive inlets, for regulating the first motive flow to the apparatus; and a first solenoid valve, fluidly connected to, and interposed between, the high-flow motive inlet and the regulator, wherein, the first solenoid valve is not interposed between the low-flow motive inlet and the regulator, and wherein the low-flow motive inlet is fluidly connected to the reactant source of the fuel cell stack such that, during operation of the fuel cell system, the first motive flow is directed to only the low-flow motive inlet when the first solenoid valve is closed and the first motive flow is directed to both the low-flow and high-flow motive inlets when the first solenoid valve is open.