GB627424A - Improvements in method and apparatus for handling finely divided materials - Google Patents

Abstract

627,424. Pneumatic conveyers. KENNEDY VAN SAUN MFG. & ENG. CORPORATION. March 15, 1947, No. 7247. Convention date, April 1, 1946. [Class 78 (i)] A method of handling powdered material comprises suspending the material in a gas stream passing through a main duct connecting a series of material redistribution points withdrawing a portion of the stream at each point ; separating the pulverised material from the gas stream of the withdrawn portion and passing the thus separated gas stream containing suspended dust back into the main dust at each redistribution point, and recycling the gas in the main duct together with any finely divided material suspended therein from a point beyond the series of redistribution points back to the intakes of the main duct, thereby preventing contamination of the atmosphere with the dust. As shown, a stream of powdered fuel and gas (e.g. air) is fed in by pipe 10 to cyclone separator 12, the fuel falling into bin 14 and the air escaping by pipe 50. The fuel from bin 14 passes through controlling valve 16 into the air stream in pipe 20 whence it is driven by fan 24 through main duct 26. The air is deflected by valves 40 in part through pipes 38 into cyclone separators 28, whence the fuel passes into bins 32 or via pipe 34 direct to a furnace and the separated air passes back via pipe 42 into main duct 26. The air carrying the remaining powdered fuel is passed round into cyclone separator 46, the fuel separating and falling through pipe 48 into bin 14 and the air passing off through pipe 50. If additional air is required to make up for losses its inlet into pipe 20 is controlled by valve 22 ; if there is any surplus air (from pipe 10) it is disposed of through pipe 54. Pipe 52 permits fuel-carrying air, after partial separation in separator 12, to be re-separated in separator 46.