Cryogenic pump

Abstract

This cryogenic pump comprises: a pump body ( 2 ) inside which is a piston ( 26 ) mounted so as to be mobile in translation along an axis ( 24 ) referred to as the longitudinal axis and bounding a pumping chamber ( 31 ), means for supplying liquid to the pumping chamber ( 31 ) and means for discharging pressurized liquid from the pumping chamber ( 31 ), comprising a discharge valve ( 40 ) mounted in a discharge valve body ( 18 ) mounted on the longitudinal axis ( 24 ), the supply means comprising a supply valve ( 42 ) arranged at the periphery of the discharge valve body ( 18 ).

1 . A cryogenic pump comprising:
 a pump body ( 2 ) inside which is a piston ( 26 ) mounted so as to be mobile in translation along an axis ( 24 ) referred to as the longitudinal axis and bounding a pumping chamber ( 31 ),   means for discharging pressurized liquid from the pumping chamber ( 31 ), comprising an outlet realized in a discharge valve body ( 18 ) mounted on the longitudinal axis ( 24 ), said outlet being closed by a discharge valve ( 40 ) mounted in said discharge valve body ( 18 ),   means for supplying liquid to the pumping chamber ( 31 ), comprising a supply valve ( 42 ) arranged around the outlet of the pumping chamber, and   a supply chamber ( 60 ) arranged about the discharge valve body ( 18 ) in communication with the pumping chamber ( 31 ) via at least one passage whose opening and closing are controlled by the supply valve ( 42 ),   characterized in that   the supply chamber ( 60 ) is closed on the side opposite the piston ( 26 ) by a cover ( 12 ) comprising a first passage to allow a supplying of cryogenic liquid from the supply chamber ( 60 ) and a second passage to allow a discharging of pumped liquid.   
     
     
         2 . The cryogenic pump as claimed in  claim 1 , characterized in that the discharge valve body ( 18 ) is a machined tubular monobloc piece, having a seat ( 38 ) for the discharge valve. 
     
     
         3 . The cryogenic pump as claimed in  claim 1 , characterized in that the discharge valve is a conical valve ( 40 ) cooperating with the discharge valve seat ( 38 ). 
     
     
         4 . The cryogenic pump as claimed in  claim 1 , characterized in that the supply means comprise, on the one hand, entry orifices ( 36 ) arranged on the periphery of a front face of the discharge valve body ( 18 ) and, on the other hand, a shutter ( 42 ) of annular shape adapted to the shape and disposition of the entry orifices ( 36 ), said shutter ( 42 ) being movable between an open position enabling the passage of a fluid through the entry orifices ( 36 ) and a closed position in which all the entry orifices ( 36 ) are closed by said shutter ( 42 ), elastic means ( 44 ) biasing the shutter ( 42 ) in its closed position. 
     
     
         5 . The cryogenic pump as claimed in  claim 2 , characterized in that the entry orifices ( 36 ) are integrated in the discharge valve body ( 18 ), being arranged on the periphery of the hollow portion of this valve body. 
     
     
         6 . The cryogenic pump as claimed in  claim 1 , characterized in that the discharge valve body ( 18 ) is mounted directly on the pump body ( 2 ) by clamping. 
     
     
         7 . The cryogenic pump as claimed in  claim 1 , characterized in that the cover ( 12 ) has an overall shape of revolution about the longitudinal axis ( 24 ). 
     
     
         8 . The cryogenic pump as claimed in  claim 1 , characterized in that the cover ( 12 ) has a bulging shape, its concavity being oriented toward the interior of the pump. 
     
     
         9 . The cryogenic pump as claimed in  claim 1 , characterized in that the cover ( 12 ) furthermore has a degassing fitting ( 14 ). 
     
     
         10 . The cryogenic pump as claimed in  claim 1 , characterized in that the pump body ( 2 ) is surrounded by a shell ( 48 ) of overall cylindrical shape, closed at the end on the side with the discharge valve by the cover ( 12 ) so as to laterally bound the supply chamber ( 60 ) designed to receive the liquid being pumped, said supply chamber ( 60 ) also extending partly around the pump body ( 2 ). 
     
     
         11 . The cryogenic pump as claimed in  claim 10 , characterized in that it comprises a second shell ( 56 ) mounted concentrically around the first shell ( 48 ) so as to form an insulating enclosure ( 8 ) around the pump body ( 2 ). 
     
     
         12 . The cryogenic pump as claimed in  claim 11 , characterized in that the cover ( 12 ) closes the supply chamber ( 60 ) around the pump body ( 2 ) designed to receive the liquid being pumped and the insulating enclosure ( 8 ).