COOLANT MIXTURE SEPARATOR ASSEMBLY FOR USE IN A POLYMER ELECTROLYTE MEMBRANE(PEM) FUEL CELL POWER PLANT

A liquid-gas separator assembly (4) is used in separating gas bubbles from a liquid coolant which liquid coolant is used in a polymer electrolyte membrane (PEM) fuel cell power plant (2). The assembly includes a cylindrical housing (38) containing a central tube (42) which is surrounded by an annular chamber (44). The annular chamber is defined by the outer surface of the central tube and the inner surface of the cylindrical housing. An inlet line (24) injects a stream of the coolant from the fuel cell stack area of the power plant into the bottom of the central tube in a tangential flow pattern so that the coolant and gas bubble mixture swirls upwardly through the central tube. The swirling flow pattern of the coolant and gas bubble mixture causes the gas bubbles to separate from the liquid coolant so that the gas in the mixture will migrate to the central portion of the swirl tube and the liquid component of the mixture will centrifugally migrate to the inner wall of the swirl tube. The gaseous component of the separated mixture is then expelled from the housing through an outlet (46) in the upper portion of the housing, and the coolant liquid descends through the annular chamber to the bottom of the housing where the coolant liquid will be returned to the cell stack area of the power plant. The gas bubbles may include reactant from either the cathode (8) or the anode (10). The separator of this invention is particularly useful in mobile applications since it is less sensitive to vehicular acceleration forces. L'invention concerne un ensemble (4) de séparation liquide-gaz utilisé dans la séparation de bulles de gaz d'un liquide de refroidissement, utilisé dans une centrale électrique (2) à pile à combustible à membrane électrolytique polymérique (PEM). L'ensemble comprend un logement cylindrique (38) contenant un tube central (42) entouré par une chambre annulaire (44). La chambre annulaire est définie par la surface extérieure du tube central et la surface intérieure du logement cylindrique. Une ligne (24) d'entrée injecte un flux de liquide de refroidissement de la zone d'empilement des piles à combustible de la centrale électrique dans la partie inférieure du tube central selon un flux tangentiel, de manière que le mélange de liquide de refroidissement et de bulles de gaz monte en tourbillonnant dans le tube central. Le flux tourbillonnant du mélange de liquide de refroidissement, et des bulles de gaz permet de séparer les bulles de gaz du liquide de