GB898257A - Rotary pumps of the circumferential flow type - Google Patents

Abstract

898,257. Circumferential-flow pumps; stuffing-box substitutes. LAHTI, P. April 8, 1960 [April 10, 1959], No. 12625/60. Classes 110 (1) and 122 (5). A circumferential-How pump comprises an arcuate suction groove 23, Fig. 2, and an arcuate discharge groove 24, both formed in a partition 5 which, as shown in Fig. 1, may be separable from the remainder of the pump casing 1. The pump impeller 10 operates within a chamber 7. The suction passage 20 tapers towards its junction with the suction groove 23, the groove 23 being of uniform depth from the junction to the beginning of the ridge 25 separating the grooves 23 and 24 and thereafter gradually decreasing in depth. The discharge groove 24 increases in depth towards an opening 28, Fig. 9, communicating with a discharge chamber 27. An opening 30 at the centre of the discharge chamber 27 communicates with the discharge pipe 31. Initially, the pump is filled with liquid through an inlet 35 (normally closed by a plug). Thereafter, sufficient liquid remains in the chamber 27 when the pump is stopped to enable the pump to be restarted without refilling. During starting, air separates centrifugally from the liquid and moves inwardly towards the central opening 30, where it enters the discharge pipe 31, while the liquid is partly recirculated through one or more holes 33 leading back to the chamber 7. A sealing ring 11 is pressed by a spring 15 into sealing contact with a stationary ring 17 and is sealed to the pump shaft by an annular member 14 of rubber or other resilient material. Two axially extending grooves in the inner wall of the ring 11 are engaged loosely by projections 12, 13 on the shaft.