GB305214A - Improvements in or relating to means for controlling the running of centrifugal machines - Google Patents

Abstract

305,214. Soc. Rateau. Feb. 2, 1928, [Convention date]. Void [Published. under Sect. 91 of the Acts]. Regulating or controlling; casings.-A centrifugal fan or pump is controlled by the introduction of a ring member into the diffuser, the member being displaced in a direction parallel to the axis. In the form shown in Fig. 1, the rotor a delivers fluid to the volute b through the diffuser c. A vane ring d can be inserted into, or withdrawn from the diffuser according to the conditions of pressure and output required. Pipes h, f connected to the volute and rotor chamber respectively, may be connected by a cock i to a tube g. With the tubes h, g in connection, as shown, the vane ring d is moved to position in the diffuser, whilst when the tubes f, g are in connection the ring d is moved out of the diffuser which is then vaneless. The ring may be mounted on helicoidal slides to promote even movement. Two vaned rings may be employed, a ring being mounted on each side of the machine, the vanes of the rings being adapted for different running conditions. In a modification, two combined rings d<1>, d<2>, Fig. 5, with vanes of different pitch, can be brought into position in the diffuser by means of a number of screws j. In another modification the ring d, Fig. 6, is left in the diffuser and the delivery is modified by moving the cheek k by means of the screw j to vary the effective width of the vanes. In another modification the vane block d, Fig. 7, can be retracted from the diffuser, and the cheek k can be moved to vary the distance between the diffuser walls. The arrangement may be applied to multi-stage machines.