GB876614A - Improvements relating to machines for inducing flow of fluid, for example, blowers - Google Patents

Abstract

876,614. Transverse-flow blowers and pumps. FIRTH CLEVELAND Ltd. July 2, 1957 [Dec. 7, 1956], No. 44294/60. Divided out of 876,611. Class 110 (1). In a transverse-flow blower or pump comprising means co-operating with a drum-shaped bladed rotor for guiding the whole throughput twice through the rotor, the guide means comprises one or more guide members facing the rotor and extending the length thereof, the member or members being movable from one position to another whereby a free vortex having its core interpenetrating the rotor blades is shifted to an opposite location for the purpose of reversing the flow, the direction of rotation of the rotor remaining the same. In the transverse-flow blower shown in Fig. 1, auxiliary walls 20, 20<SP>1</SP> are pivotally connected at 18, 18<SP>1</SP> respectively to side walls of the casing, and are formed with arms 21, 21<SP>1</SP> which are interconnected by a tension spring 23 so as to bear against a cam 22. When the cam 22 is in the position shown, wall 20 is flush against the adjacent surface of the casing while wall 20<SP>1</SP> fairs smoothly into a curved surface 13 of the casing. When the impeller 1 is rotated in the direction indicated, the flow is in the direction shown, with flow lines F conforming to a free cylindrical vortex having a core V adjacent a curved surface 131 of the casing. If the cam 22 is turned through 180 degrees, wall 201 is retracted into the flush position and wall 20 moves to a position in which it fairs smoothly into the curved surface 13<SP>1</SP>. The vortex core V now occurs adjacent the curved surface 13, and the flow is reversed without reversal of the direction of rotation of the impeller. By setting the cam to intermediate positions the output of the blower can be varied in either direction of flow, zero output being obtained when the cam is at 90 degrees to the position shown. Fig. 3 shows an embodiment in which casing walls 33, 34 are carried by linkages 36 so that they can be moved parallel to themselves from the full-line positions to the dotted positions whereby the direction of flow is reversed. As in the previous embodiment, the output can be varied by setting the walls 33, 34 to intermediate positions. In transverse-flow machines in which stationary guide members are provided within the impeller, as described in Specification 876,612, the guide members may be angularly movable to reverse the direction of flow.