Patent GB-606267-A (GB)
Title: Improvements in or relating to apparatus for feeding finely divided material
IPC: F23K3/00
Filed: 1945-06-11
Abstract: 606,267. Pneumatic conveyers. BABCOCK & WILCOX, Ltd. June 11, 1945, No. 14717. [Class 78 (i)] Apparatus for supplying a mixture of finelydivided material and gas carrier comprises a storage space 10, Fig. 1, for the powder ; an aerating chamber 21; means e.g. screw 19 for supplying powder from storage space 10 to aerating chamber 21, whilst aeration is taking place in the latter chamber; means for maintaining the powder in the aeration chamber 21 at a limited depth; inlet means 25 for the gas below the powder surface and an outlet means 23 for entrained powder above the powder surface. A mixture of powdered fuel and air is fed from a pulveriser through conduits 11, Fig. 1, to deposit the fuel in receptacle 10, the air being discharged through outlets 45. The fuel is stirred by agitator blades 18 and forced by screw conveyer 19 into aerating chamber 21. Excess fuel drops back into receptacle 10 through overflow ports 31, the main body being entrained by air flowing from fan 38, via passageway 35 and through circular ports 25 and passing out the mixture through outlet pipes 23 to burners. Electric motor 42 drives blades 18, screw 19 and annular cup member 27 which fits over circular ports 25 and the movement of which keeps the ports clear of dust. In the modification of Fig. 4, air-fuel mixture is introduced tangentially to separator 46, the air escaping by outlet 48 and the dust falling to the bottom of bin 47, where it is collected by screw 49 and delivered to chamber 53, where it is fed with compressed air through circular ports 58 kept clear of dust by revolving cap member 60. The entrained dust discharges through outlets 56, whilst excess dust overflows through ports 67 into chamber 68 whence it is fed back to bin 47 by two screw conveyers (not shown). Inlet of compressed air may be valve controlled. In the third example of Fig. 9, intended for mounting on a locomotive tender, air and fuel is introduced into separators 106, the air being vented by outlets 108, 109 and the dust falling into bin 105 whence it is carried by conveyer 110 and dropped through port 117 and spout 118. Air from chamber 144 in passing through concentric ports 127 entrains coal and discharges it through outlet ports 125. Cap members 129 oscillate on shaft 133 to-keep the ports 127 clear. Rate of control of flow of air is controlled by valve 147. Pipes 142 allow excess fuel to flow back into bin 105. In Fig. 8, pulveriser 80 supplies air-fuel mixture to burners 83 of locomotive furnace 82 through valves 84, and also to feeder unit 81 through 3-way valves 88 and valves 94, the feeder unit 81 being provided with air vents 93, 98 and air-fuel discharge outlets 95. Airfuel mixture is fed to the feeder at the same time as to the furnace so that fuel may be accumulated therein, which source of fuel may be used to supplement the supply direct from the pulveriser when extra power is needed or to replace it when the fuel demand is too small to be met therefrom. The rate of discharge of powdered material may be measured by the rate of inflow of air to the aerating chamber.