GB651382A - An improved centrifugal pump - Google Patents

Abstract

651,382. Centrifugal pumps. CLARK, J. Nov. 4, 1948, No. 28663. [Class 110(i)] A centrifugal pump has an impeller comprising tapered or conical inner and outer shells with spiral vanes between them, forming a number of axially extending spiral ducts which increase in diameter from the inlet end and are each of substantially uniform cross-sectional area throughout its length, the liquid delivered by the impeller being received by non-rotatable spiral ducts which guide it inwardly and axially to the discharge. The pumped liquid passes through inlet ducts 15a, impeller ducts 21, and discharge ducts 29, all of helical form. The ducts are bounded by outer members 13, 19, and 7, inner members 15, 18, and 25, and helical vanes 14, 20, and 28. The pitch of the vanes 20 is increased sharply at their delivery ends. The impeller members 18 and 19 are of conical form, and the discharge members 7 and 25 are of semispherical form; in both cases the space between the inner and outer members varies in longitudinal section so that its transverse cross-sectional area remains substantially constant. The ducts 21 and 29 are of uniform cross-sectional area throughout their lengths. Pressure liquid is supplied through a pipe 32 to the inlet 6 for priming purposes, and also through a pipe 30 to an annular channel behind a balance ring 23 which abuts a flange 22 on the impeller. The ring 23 is prevented from rotating by pins 24. According to the Provincial Specification, pressure liquid is supplied to an annular recess provided on the face of the impeller flange which abuts the balance ring.