GB164732A - Improvements in centrifugal fans or blowers - Google Patents

Abstract

164,732. Weiss, L., and Mandler, E. June 12, 1920, [Convention date]. Regulating; casings.-The delivery head of a centrifugal fan a is increased and regulated by allowing a part of the air from the fan to escape through a diffuser of one or more expanding exhaust channels to reduce the outlet resistance. On the outlet side of the fan, the gap s, formed between the bearing shield c and the casing wall d, for the passage of the air, may be regulated in size by the axial movement of a damper e on the shield c. On the other side of the fan is a gap s<1> between the suction plate f and the casing plate g, and by extending these plates radially the space s<1> is caused to act as an expanding diffuser in which the escaping air partly converts its velocity into pressure. Or this diffuser may be replaced by guide-vanes, or a spiral casing &c. Regulation of the air passing through the gap s' is effected by the movement of the plate f the flange of which has helical slots h engaging with studs i secured to the casing. A rotation of the plate by the handle k produces an axial displacement to vary the gap. By constructing the plate as shown in dotted lines, communication between the suction and outlet sides may be completely stopped. The air from the diffuser s<1> may be conducted back to the suction side.