GB1171677A - Radial Flow Fan for Pneumatic Conveying Installations - Google Patents

Abstract

1,171, 677. Centrifugal fans. LUWA A. G. June 2, 1967 [June 8, 1966], No.25641/67. Heading F1C. A radial-flow for pneumatic conveying installations comprises a non-rotating diaphragm 11 forming a rigid guide surface for the flow through the fan impeller 16, the diaphragm being arranged to be capable of axial deflection in a resilient manner relative to the impeller to permit a wobble movement of the diaphragm in the event of entry into the fan of a foreign body. The diaphragm 11, which comprises a conical main part 13 and outer and inner flanges 12, 14, is resiliently connected to a wall 1 by bolts 5 and springs 24 and is sealed to the wall by a flexible sealing ring 15 and a flexible bellows 23. If any of the material, e.g., textile fibres, being conveyed in the air flowing through the fan becomes trapped in the gap between the impeller blades 18 and the conical part 13 of the diaphragm, the trapped material presses the diaphragm locally away from the impeller so that the diaphragm is given a wobble motion as the material is carried round by the impeller. The local increase in the gap between the impeller and the diaphragm, which increases in the radially outward direction, permits the release of the trapped material this release being further promoted by centrifugal force. The springs 24 may be replaced by other resilient means such as rubber or synthetic plastics material. It is stated to be known to provide a non-rotating flexible membrane, as of rubber, at each side of the impeller of a pump for conveying sand, gravel or waste water, the membranes being acted upon from the outside by a pressure medium.