GB675113A - Improvements relating to apparatus for conveying powdered or granular materials - Google Patents

Abstract

675,113. Pneumatic conveyers. EVERY, C. E. (Smidth & Co. Aktieselskab, F. L.). July 3, 1950. [Sept. 15, 1949] No. 23851/1949. Class 78 (i) Powdered or granular material is conveyed pneumatically by first fluidising a batch of it in a container solely by the injection of a gas without any substantial rise of pressure and then subjecting it in the same or another container to a substantial pressure by which it is driven in the fluidised state into and along a pipe line. Material is admitted into a container 18, Fig. 1, through an inlet 23 and rests on a conical porous plate 19 of canvas, felt or filter stone. This plate may be replaced by a system of pipes having a large number of openings covered by porous material. Air is supplied to the space 22 below the plate by a pipe 10 and passes through the plate and material to escape through the inlet 23. The supply of material is cut off when the container is full by the actuation of a switch 27 by pressure of the material on the member 24. When the material is fluidised, the valve 3 is opened and it then flows rapidly into the container 1. When the transfer is complete the valve 3 is closed by pressure of the material on a member similar to the member 24 and the valve 11 is opened to admit air to the container through the pipes 12, 13, 14 to force the material through the outlet 8 into the pipe line. Air admitted through the pipe 12 passes through porous screens 15. In a modification the container 18 is a shallow box with an inclined porous bottom and is mounted with its base on the same level as that of a grinding machine supplying material. The top of the tank 41, Fig. 3 is fitted with an inlet 46 and an air outlet 47 incorporating a filter and valve. Aerating devices 42 disposed in the bottom of the tank each consist of a shallow box 45, Fig. 5, having a porous cover 42a. When material is to be discharged, the valve 47 is opened and compressed air is forced by a compressor 44 driven bv the engine of the vehicle through a pipe 43 to the boxes 45. When the material is fluidised, the valve 47 is closed and the pressure rises until the loaded valve 48 is forced open and the material is driven through the outlet 49 to the delivery hose. Material passes from a hopper 73, Fig. 8, through a shoot 68 into a tank 63 and rests on a porous plate 64 through which compressed air passes upwardly from the pipe 70. When the material is fluidised, the piston 66 is forced downwards, thereby closing the shoot 68 and opening a loaded valve 72 leading to the pipe line 71. In modifications (not shown) the transference of material between a silo on shore and a ship's hold is described.