A SUBMERGED FUEL PUMP FOR PUMPING LIQUIDISED FLUIDS

The present disclosure concerns a submerged fuel pump for pumping liquidised fluids, in particular a cryogenic submerged fuel pump for pumping liquidised fuel, such as liquid natural gas (LNG), hydrogen, methanol, ethane, liquefied petroleum gas (LPG) or the like, said pump comprising a housing (1) having a lower fluid inlet (3') and an upper fluid outlet (3") and accommodating a vertically oriented pump shaft (4); a permanent magnet electrical motor (2) having a rotor with a hollow motor drive shaft (22) and a stator (24) around said rotor; at least one impeller (5), which is mounted to the pump shaft (4), for centrifugally moving cryogenic fluid from a pump inlet to a pump outlet; wherein a main liquid flow (6) having a main flow direction from the pump inlet to the pump outlet is provided coaxially around the electrical motor (2); and a secondary liquid flow (7) for cooling the electric motor (2) and lubricating bearings (27,28) in the pump, where said secondary flow (7) is a reverse liquid flow essentially opposite of the main flow (6) direction from the region of the pump outlet through the electrical motor (2) to a radially central space (7A) on the upper side of the at least one impeller (5) in the region of the pump inlet (3'), and wherein a filter (71) is provided at the inlet of the secondary liquid flow path (7).