GB312474A - Improvements in or relating to distribution means for pulverulent material - Google Patents

Abstract

312,474. Alden, G. R., and Skentelbery, C. May 9, 1928. Pneumatic conveyers. -A distributing device for pulverulent material such as pulverized fuel, cement, flour, &c. carried by air or gas under pressure through pipes from a common source of supply comprises a circular chamber having an inlet and a plurality of outlets equally spaced apart and equidistant from the central axis of the chamber and means for creating a whirl within the chamber concentrically with its axis for the purpose of distributing the material equally to the several outlets. The supply 6 for the material is connected to. an inlet 5 in the centre of the detachable dome-shaped cover 2 of the circular chamber 1. Outlets 12 communicating with distribution pipes 13 :are formed at equal distances apart around the periphery of the lower portion 4 of the chamber. An impeller disc 9 in the lower part of the chamber is mounted ,on a shaft 8 which .is rotated by a motor 17. The disc 9 has Mades 10 on its upper surface and blades 11 on its lower surface. The motor 17 drives an air compressor 23 which supplies air to a receiver 25 from which a pipe 26 leads to a bore in the bearing 7 of the shaft 8. Compressed air passes through this bore, beneath a conical disc 28 to the space between the bottom of the ..disc 9 and the casing 4 and in conjunction with the blades 11 prevents the passage of material to the underside of the disc. For the purpose of obtaining an intimate mixture of air or gas with the pulverulent material in desired proportions, when supplying powdered fuel to furnaces, air inlets 32 are provided in the inner wall of an annulus 30 disposed between the pipe 6 and cover 2. The opening of these inlets is regulated by a rotatable sleeve member 33. Hot air is supplied to the annulus by a pipe 31. One or more auxiliary air inlets having spring-loaded valves may be provided in the wall of the chamber 1 to admit air if the pressure in the casing falls below a predetermined limit. The disc 9 may be replaced by a disc freely supported in the casing and rotated by the air current carrying the material, or by a fixed device having blades thereon which serve to define distributing channels for the streams of air and the materials suspended therein. In Fig. 3 the device is shown supplying fuel to the burners 34 of a battery of three boilers. In order to prevent choking of the pipes 13 when one or other of the burners is shut-off, bye-pass pipes 36 are provided which connect each pipe 13 with a return pipe 37 communicating with a branch 6a of the inlet pipe. Valves 38 on the pipes 36 are opened automatically or otherwise when the adjacent burner is shut-off. The bye-passed material may be returned directly to the distributing chamber or to the source of supply.