GB749629A - Centrifugal blowers or pumps - Google Patents

Abstract

749,629. Centrifugal pumps and blowers. BUCHI A. April 21, 1953 [April 24, 1952], No. 10992/53. Class 110(1) In a flow guide device for a centrifugal blower or pump comprising diffuser guide ducts each divided in the flow direction along a plane normal to the rotor axis in two sections in separate casing parts, the guide ducts each being deflected in axial direction so as to discharge the fluid in a nearly peripheral direction through an outlet in an axially offset space in a further casing part, the leading edge of each outlet on one side of the offset space and the trailing edge on the other side are arranged without overlap as seen in the axial direction, to facilitate production by the use of press tools or repeatably usable moulds. A blower, Figs. 1 and 2, comprises housing sections A, B. C. D which are separable from one another in planes normal to the axis of the blower and contain guide passages which are formed by open recesses without undercut walls. The section D forming the suction conduit, is divided into two parts on a diametral plane. Collecting passages 5 open into straight diffuser passages 6 of circular cross-section which are followed by diffuser passages 7 of which the cross-section changes from circular to partly rectangular, as shown in Fig. 1. Each diffuser passage 7 is formed by complementary recesses 7<SP>1</SP> and 7<SP>11</SP>, formed in sections A and B respectively. Each recess 7<SP>1</SP> progressively deepens until it breaks through at a position b' to the other side of the section A whence the diffuser passage 7 is continued by a recess 7<SP>111</SP> which extends, with progressively decreasing depth, from a position b<SP>2</SP> to a position b<SP>3</SP>. The discharge volute 8 is formed wholly in the section C as shown or alternatively as two complementary recesses in sections A and C. In the latter case, the discharge connection C<SP>1</SP> is similarly divided into two parts. In the twostage embodiment shown in Fig. 3, the construction of the second stage is similar to that already described but, it may be, with the section C<SP>11</SP> formed as shown, without avoidance of undercut walls. Return passages 9, which are formed on the back of seection A to conduct the fluid to the second-stage impeller, are in the form of open recesses without undercut walls, covered by a plate 10.