Fuel cell

Claim 2

In a fuel cell system including: a fuel cell block defining at least one fuel cell, said fuel cell block being provided with a first group of chambers for receiving electroltye, a second group of chambers for receiving fuel and a third group of chambers for receiving comburent, each group of chambers having respective inlet and outlet orifices for receiving and discharging the fluids passing therethrough; an electrolyte feeding circuit defining an electrolyte recirculation flow path, said feeding circuit including an electrolyte tank, pump means for pumping electrolyte around said flow path and conduit means connecting said first group of chambers, said electrolyte tank and said pump means so that electrolyte flowing through said flow path passes in order through said first group of chambers, through said tank, through said pump means and then back to said first group of chambers; collecting means for collecting electrolyte leaking into said second group of chambers and said third group of chambers; and return means for returning electrolyte collected in said collecting means to said electrolyte recirculation flow path; the improvement wherein: 1. said electrolyte tank and said fuel cell block are so arranged that the inlet orifice of said tank is above the outlet orifice of said first group of chambers; 2. said electrolyte tank and said pump means are arranged so that the outlet orifice of said tank is above the inlet orifice of said pump means;

Claim 3

said fuel cell system further includes pressure drop means interposed between said tank and said pump means producing when said pump means is pumping electrolyte through said flow path a dynamic pressure drop, the value of said dynamic pressure drop being between (a) the static pressure of the electrolyte measured between the inlet of said pump means and the electrolyte liquid level in said electrolyte tank and (b) the pressure difference between the pressure at the inlet of said pump means and the outlet of said pump means; and 4. said return means returns electrolyte from said collecting means to said flow path at a location intermedite said pressure drop means and said pump means.

Claim 4

said fuel cell system further includes pressure drop means interposed between said tank and said pump means producing when said pump means is pumping electrolyte through said flow path a dynamic pressure drop, the value of said dynamic pressure drop being between (a) the static pressure of the electrolyte measured between the inlet of said pump means and the electrolyte liquid level in said electrolyte tank and (b) the pressure difference between the pressure at the inlet of said pump means and the outlet of said pump means; and 4. said return means returns electrolyte from said collecting means to said flow path at a location intermedite said pressure drop means and said pump means.

Claim 5

The fuel cell system of claim 1, wherein said electrolyte tank is open to the atmosphere.

Claim 6

The fuel cell system of claim 2, wherein said dynamic pressure drop means is a heat exchanger for cooling the electrolyte.

Claim 7

The fuel cell system of claim 1, wherein said dynamic pressure drop means is a heat exchanger for cooling the electrolyte.

Claim 8

In a fuel cell system including: a fuel cell block defining at least one fuel cell, said fuel cell block being provided with a first group of chambers for receiving electrolyte, a second group of chambers for receiving fuel and a third group of chambers for receiving comburent, each group of chambers haivng respective inlet and outlet orifices for receiving and discharging the fluids passing therethrough; an electrolyte feeding circuit defining an electrolyte recirculation flow path, said feeding circuit including an electrolyte tank, pump means for pumping electrolyte around said flow path and conduit means connecting said first group of chambers, said electrolyte tank and said pump means so that electrolyte flowing through said flow path passes in order through said first group of chambers, through said tank, through said pump means and then back to said first group of chambers; collecting means for collecting electrolyte leaking into said second group of chambers and said third group of chambers; and return means for returning electrolyte collected in said collecting means to said electrolyte recirculation flow path; the improvemet wherein: 1. the inlet orifice of said electrolyte tank is above the outlet orifice of said first group of chambers; 2. the outlet orifice of said electrolyte tank is above the inlet orifice of said pump means; 3. said fuel cell system further includes dynamic pressure drop means interposed between said tank and said pump means producing when said pump means is pumping electrolyte through said flow path a dynamic pressure drop; and 4. said return means returns electrolyte from said collecting means to said flow path at a location intermedite said pressure drop means and said pump means; the value of said dynamic pressure drop created by said pressure drop means being sufficient so that the pressure of electrolyte at said pump inlet is less than the pressure of the electrolyte at said collecting means whereby electrolyte is automatically returned from said collecting means to said electrolyte flow path.

Claim 9

In a fuel cell system including: a fuel cell block defining at least one fuel cell, said fuel cell block being provided with a first group of chambers for receiving electrolyte, a second group of chambers for receiving fuel and a third group of chambers for receiving comburent, each group of chambers haivng respective inlet and outlet orifices for receiving and discharging the fluids passing therethrough; an electrolyte feeding circuit defining an electrolyte recirculation flow path, said feeding circuit including an electrolyte tank, pump means for pumping electrolyte around said flow path and conduit means connecting said first group of chambers, said electrolyte tank and said pump means so that electrolyte flowing through said flow path passes in order through said first group of chambers, through said tank, through said pump means and then back to said first group of chambers; collecting means for collecting electrolyte leaking into said second group of chambers and said third group of chambers; and return means for returning electrolyte collected in said collecting means to said electrolyte recirculation flow path; the improvemet wherein: 1. the inlet orifice of said electrolyte tank is above the outlet orifice of said first group of chambers; 2. the outlet orifice of said electrolyte tank is above the inlet orifice of said pump means; 3. said fuel cell system further includes dynamic pressure drop means interposed between said tank and said pump means producing when said pump means is pumping electrolyte through said flow path a dynamic pressure drop; and 4. said return means returns electrolyte from said collecting means to said flow path at a location intermedite said pressure drop means and said pump means; the value of said dynamic pressure drop created by said pressure drop means being sufficient so that the pressure of electrolyte at said pump inlet is less than the pressure of the electrolyte at said collecting means whereby electrolyte is automatically returned from said collecting means to said electrolyte flow path.