Patent GB-126638-A (GB)
Title: Improvements in Pulverulent-fuel Installations for use in connexion with Furnaces.
IPC: F23K3/00
Filed: 1919-05-07
Abstract: 126,638. Quigley Furnace Specialties Co. May 8, 1918, [Convention date] Fuel, feeding.-Apparatus for preparing pulverulent fuel and conveying it to furnaces for combustion therein comprises means for crushing, drying, and pulverizing coal which is afterwards fed by pneumatic apparatus to pulverulent fuel burners located in the firing-openings of the furnaces. Raw coal is dumped from trucks into a hopper 2, Fig. 1, and is carried by an elevator 3 to crushing-apparatus 4 driven by a motor 5. The crushed coal is raised by an elevator 7 to a magnetic separator 8 from which it passes to a conveyer 14 discharging into a storage hopper 15. The hopper discharges into a reciprocating feeder 21 which delivers the coal into a shoot 22 leading to a rotary dryer 23 enclosed by the furnace casing 24. Hot gases from the furnace pass through the casing 24 and are drawn by a fan 34 through the conduit 210 and delivered to the stack 33. A stack 209, Fig. 1<a>, is connected to the other end of the furnace casing for drawing off the furnace gases by natural draught during the starting of the furnace and the preliminary heating of the dryer. Dampers 35 and 300 in the stacks are operated to control the path of the hot gases. The dried coal is fed by a screw conveyer to an elevator 37 and deposited in a screw conveyer 44 delivering to hoppers 46, 46a communicating through valve-controlled outlets with pulverizers 49 driven by motors 50. Suction fans 53 draw air and pulverized fuel from the pulverizers and deliver them to primarv cyclone separators 55, 55<a> from which the coal passes through valve-controlled outlets to a conveyer 58. Return pipes 56, 56<a> lead air from the separators to the housings 214 of the pulverizers. Excess air from the primary separators is led to secondary separators 215, 215<a>, separated coal dust being led to the conveyer 58 and air being discharged through the stacks 60, 60<a>. The conveyer 58 delivers into a hopper 63 flexibly connected to a blowing tank 71 mounted on a weighing platform 82 as described in Specification 122,836, [Class 78 (i), Conveyers &c.]. Fuel is fed from the hopper to the blowing tank in the desired quantities and is delivered through the main 76 by compressed air supplied to the tank by a pipe 72 flexibly connected to the tank, the delivery being controlled by a lever 80 connected to the internal mechanism of the tank. The main 76, which supplies fuel to a series of furnaces, is provided with valves 84, 89, Fig. 1<b>, preferably of the kind described in Specification 122,825, [Class 135. Valves &c.], for controlling the supply of fuel to the hopper such as 87 for any particular furnace. The valves are interconnected by rods 90 so that, when the valve 84 is moved to supply fuel from the main 76 through the pipe 86 to the hopper 87, the valve 89 opens communication between the hopper and the forward portion of the main through the pipe 88. A blow-off stack 170, having its lower end covered by canvas, is provided on the hopper. Fuel is fed from the lower part of the hopper to the furnace by apparatus of the kind described in Specification 121,135 connected to a nozzle 99 having a connexion 98 for low-pressure air. To avoid obstruction in the fuel and air main 76, a compressed air pipe 101 is arranged to deliver compressed air to the main at suitable points as desired. In the modification shown in Fig. 1<c>, fuel is fed from the main 76 through a single valve 105 to a separator 108 delivering fuel to the hopper 111. A return pipe 160 leads from the hopper to the separator. The connexion 163 between the separator and the hopper is expanded, and below it is placed a baffle-plate 164 provided with openings 165 to distribute the fuel uniformly in the hopper. The Specification as open to inspection under Sect. 91 (3) (a) also describes and shows a fuel feeding-device in which fuel is fed from a hopper 269, Fig. 2 (Cancelled), by a conveyer 271 to a nozzle 263 supplied with highpressure blast from a pipe 266. The nozzle is provided with a ball joint 264 and is fed also with low-pressure blast through the pipe 265. A cleaning door 275 is provided at the base of the hopper and a safety-valve 277 in an extension 256 of the pipe 268. A fuel-feeding device operating with low-pressure air blast is shown in Fig. 3 (Cancelled). The furnace is provided with an L- shaped fuel inlet 279, 280 and fuel is fed by the distributing-apparatus 281 to the ejector 282 where it meets a blast of air passing through the damper-controlled pipe 286 from the air main 285 and is fed through the pipe 283 to the vertical nozzle 284. Air also passes from the main to the annular passage 289 surrounding the nozzle 284 and through the pipe 290 to the fuel inlet. This subject-matter does not appear in the Specification as accepted.