GB968409A - Improvements in or relating to centrifugal air blowers - Google Patents

Abstract

968,409. Centrifugal blowers. J. PROSVIC. Nov. 2, 1962 [Nov. 7, 1961], No. 39810/61. Heading FIC. A centrifugal blower comprises a housing having an inlet opening allowing access of air to the interior of the impeller and an exit opening for delivery of air from the exterior of the impeller, the impeller being driven by an electric motor secured to the housing, a main portion of the housing extending around part of the impeller periphery at a spacing therefrom which increases in the direction of rotation, and the exit opening having one wall portion extending substantially radially to, or parallel to a radius of, the impeller, and an oppositely lying wall portion which is curved convexly towards the outside, whereby to provide a diverging exit passage. The blower shown comprises an impeller 2 of shallow-overhang type operating within a casing 1 having a wall 11 of increasing distance from the impeller in the direction of rotation. The divergent exit 7 is bounded by a wall 13 which is convex towards the outside and a wall 12 which may extend substantially radially with respect to the impeller. The impeller blades 14 have convex leading surfaces and their edges at the interior of the impeller are the leading edges. The blades 14 may be supported at one end by a back plate, in which case the driving motor may be nested within the impeller. Alternatively, the supporting plate may be substantially midway between the ends of the blades, the housing 1 then having an inlet at each end. An electric heater 8 may be provided.