GB190724985A - Improvements in or relating to Centrifugal and other Pumps. - Google Patents

Abstract

24,985. Rossiter, J. T. Nov. 11. Centrifugal pumps; piston pumps.-In centrifugal pumps used for pumping liquid containing suspended matter, a portion of the liquid is separated in a clean state for use in the stuffing-boxes, bearings, and end-thrust balancing devices. Fig. 1 shows the construction of an impeller b used to effect the separation. Holes c guarded by shrouds d are formed in one or both disks. Clean water passes through these into chambers a<2>, grit being carried past into the outlet i. Leakage between the chambers a' and i may be prevented by blades b<2> fixed on the outside of the impeller disks, or machined flanges may be provided on the shrouds d to form a tight running joint with the casing. The guard d may be formed as a pocket over each hole instead of a continuous annular shroud. The holes c may be formed in an enlargement of the impeller, and the shrouds d may be modified in form. The clean water is led from the chamber a<2> to the stuffing-boxes g by pipes f. In a modification the chambers a<2> deliver into a common main. Fig. 3 shows a further modification in which fixed pipes e<1> having scoop-shaped ends e<2> project into a revolving chamber e. A separate centrifugal separator, as above described, may be employed to supply clean liquid to the stuffing-boxes &c. of centrifugal or reciprocating pumps. Fig. 12 shows the manner in which clean water is supplied to the balancing device of multi-stage centrifugal pumps. Balance chambers v, t are provided as in Specification No. 4811A, A.D. 1907, but the external connecting-pipes are dispensed with. The chamber v is put into communication with an intermediate stage of the pump by means of symmetrically-arranged passages v<1> leading down through the first impeller b and through the boss of the second impeller b<1>. The entrance v<3> to this passage is so placed that heavy matter does not approach it. Clean liquid leaks past the running joint j into the chamber t. A passage s<1>, the size of which varies with axial displacements, connects the chamber t with a cavity s, which communicates with the suction a<1> through symmetrically-arranged passages r in the bosses of the impellers b, b<1>, b<2>. The passages v<1>, r may be formed in the shaft or in a separate sleeve. Channels g<1> lead clean water to the stuffing-boxes.