GB530149A - Improvements in or relating to fans incorporating dust collectors - Google Patents

Abstract

530,149. Centrifugal dust separators. HOWDEN & CO., Ltd., J., and ULANDER, H. N. June 19, 1939, No. 17801. [Class 23] [Also in Group XXVI] A dust collector is incorporated with the inlet 24 of the fan 22 and consists of a casing 25 having angularly adjustable guide vanes 27 arranged around the fan inlet, the vanes being controllable differentially individually or in groups. As shown in Fig. 2, the vanes are arranged in four groups A, B, C. D and each vane is provided with an external control arm 33. The arms in each group are connected by pivots to a curved link 34, and the pivot at the upstream end of each link enters the appropriate cam slot in the operating ring 28 which can be adjusted annularly by the operating link 36. The slots are shaped so that when the ring is rotated counter - clockwise from its zero position, the vanes of group A close first, then the vanes of group B, and then the vanes of groups C, D close together. An intermediate position is shown in Fig. 2, with group A closed and group B partly closed. The operation of the vanes may be secured in various ways; the slotted ring 28 may be omitted, and be replaced by rotary cams operating rock levers, or by a rotary disc with angularly spaced cranks and connecting links. In the modification shown in Fig. 10, the adjustable vanes 70 are arranged outside a set of fixed vanes 71. The pivots 72a of the vanes 70 are offset from the vanes so that as the vanes are moved in groups by the operation of their connecting links 34, they close to form an effective screen at some distance from the edges of the vanes 71, while in the open position they offer little resistance to fluid flow.