GB831277A - Gravity operated conveyors and feeding installations for granular materials - Google Patents

Abstract

831,277. Pneumatic conveyers; hoppers. CENTRAL ELECTRICITY GENERATING BOARD, and LUCAS, D. H. L. Dec. 4, 1957 [Sept. 4, 1956], No. 27078/56. Class 78 (1). The flow of granular materials, e.g. small coal, from a main storage bunker 30 into a subsidiary bunker 65 and its discharge therefrom, is stimulated by the intermittent admission of compressed air through one or more rotating nozzles 68, 32 at points where the flow may be impeded. Each nozzle consists of an outer tube 40, to which compressed air is supplied through a tee 41, and an inner tube 42 slidably mounted therein. An aperture 39 is provided in the tube 42 adjacent its closed end 43 and the other end is secured by welding to the forked end 44 of a rod 45 which is slidably mounted in a bush 46 inserted in one end of the tee. A bearing plate 47 is mounted on the bush and forms an abutment for a compression spring 49. The spring bears also on a plate 48 attached to the end of the rod 45. A twisted bar 53 of square section is attached to the rod 45 and passes through a square hole 54 in a U-shaped stirrup 55, the ends 56 of which are pressed hard against the plate 47 by a compression spring 58. When a blast of air is admitted through the tee, the pressure of the air on the plate 43 will cause the tube 42 to move to the left and the movement of the bar 53 through the hole 54 will cause it to rotate since the rotation of the stirrup 55 is prevented by friction. When the air supply is cut off, the spring 49 returns the tube to its retracted position and since the friction between the twist 53 and the stirrup is now less, the stirrup will turn through a small angle and carry the tube 42 with it.