GB673812A - Improvements in or relating to guiding arrangements for centrifugal blowers and pumps - Google Patents

Abstract

673,812. Centrifugal pumps. BUCHI, A. March 6, 1947 [March 6, 1946], No. 6323/47. Class 110(i) The impeller discharges into a number of passages each comprising a straight portion and a curved portion in a radial plane and a laterally-deflecting outlet into a scroll case, or one of two half-scroll cases, arranged at the side of the impeller casing and of the same outside diameter. The casing of the pump may be made in two or three parts meeting on radial planes. Pumps of different outputs may be produced from standard castings or stampings by machining off the meeting faces to a greater or smaller extent or by fitting inserts of various sizes in the passages. In the form shown, each discharge passage leading from the impeller chamber 10 comprises an entrance portion 11, a straight portion 13 and a curved portion 14, both of increasing section and with their axes in a radial plane, and an outlet portion 15 opening into the scroll-case 8 which is arranged at the side of the impeller and discharge casing and made of the same outside diameter. The entrance to the passage portion 13 may be cylindrical for a short distance, and may be of smaller size than the entrance portion 11. The scroll-case starts from one of the discharge passages and enlarges to take the output from each successive one, and is, together with the passage portions 15, dimensioned to give uniform velocity of flow; its outlet 18 may be parallel or diffuser-shaped. The impeller and discharge-passage casing is formed in two halves 4, 5, Fig. 6, meeting on the radial plane of the impeller, and the scroll-case 8 may be integral with the part 5 or, as shown, formed separately to avoid the need for casting hollow parts. Guide vanes 14<SP>1</SP> may be provided in the curved passage portions 16; they are made in two parts, integral with or attached to the respective half casings 4, 5. The pump may have an inlet on each side of the impeller. In a multi-stage pump the discharge passages 'open into a common chamber extending radially, with guide vanes, to the inlet of the next stage. Specification 673,883, [Group XXII], is referred to.