Centrifugal pump

Claim 1

IN A FLUID PUMP HAVING A CENTRIFUGAL IMPELLER WITH A CIRCULAR PERIPHERY AND ROTATABLE TO IMPEL FLUID, A CASING HAVING AN ANNULAR IMPELLER CHAMBER ABOUT SAID IMPELLER, SAID CASING HAVING A DISCHARGE PASSAGE TERMINATING IN A DISCHARGE NOZZLE, A FLOW CHAMBER IN SAID CASING BETWEEN SAID DISCHARGE PASSAGE AND SAID IMPELLER CHAMBER, SAID DISCHARGE PASSAGE BEING CIRCULAR IN CROSS-SECTION AND HAVING AN AXIS TANGENT TO THE PERIPHERY OF THE IMPELLER THROUGHOUT ITS LENGTH, SAID FLOW CHAMBER BEING OF U-SHAPE IN CROSS-SECTION WITH THE OPEN SIDE OF THE U IN DIRECT COMMUNICATION WITH SAID IMPELLER CHAMBER, THE U-SHAPED FLOW CHAMBER TERMINATING IN AN END WALL LYING IN A PLANE NORMAL TO THE AXIS OF THE DISCHARGE PASSAGE AND CONTAINING AN INLET TO SAID DISCHARGE PASSAGE, SAID END WALL EXTENDING ABOVE AND BELOW THE INLET AND HAVING A SURFACE AREA THAT EXCEEDS THE CROSS-SECTIONAL AREA OF THE INLET TO SAID DISCHARGE PASSAGE, AND SAID END WALL FORMING AN ABUTMENT IN THE FLOW PATH FROM THE IMPELLER AND HAVING AN AXIAL WIDTH SUBSTANTIALLY EQUAL TO THE INLET DIAMETER OF THE DISCHARGE PASSAGE.