Patent GB-581681-A (GB)
Title: Improvements in and relating to power plant
IPC: F01K15/04
Filed: 1941-03-02
Abstract: 581,681. Motor power plant. BAILEY, R. W., and METROPOLITAN-VICKERS ELECTRICAL CO., Ltd. March 2, 1941, Nos. 67/41, 1695/41, 17559/40, 6237/41, 7013/41 and 7766/41. [Class 110 (iii)] [Also in Group XXVII] In a power plant for frequently or widely varying loads, comprising a high - compression internal - combustion engine 1 running alternatively or simultaneously on producer gas and oil, a gas producer 11 normally operating on coal or like solid fuel, and means for generating and superheating steam, the final stage of the superheating is effected by heat generated in the gas producer, at least some of the gas from which is used as fuel for the internal-combustion engine. Provision may be made for cutting out or byepassing the final stage of steam superheating when the gas producer is inoperative. The steam may be used in a power unit or for processing or other purposes. The steam generator preferably uses solid fuel normally, but may be heated alternatively by oil. In the arrangement shown in Fig. 1, the steam generated is used in the steam turbine 2 of a marine power plant, the turbine driving through gearing 12 to supplement the engine 1 as described in Specification 581,680, and the gas producer 11 may be one which removes tar from the producer gas as described in Specification 579,967, [Group XII]. The engine 1 may drive the propeller shaft direct or through toothed gearing and a hydraulic or other flexible coupling, and the power from the steam prime mover may be transmitted electrically to the propeller shaft. The turbine exhausts to a condenser 4 and the condensate is pumped to the jacket 6 of the engine 1. Water from the jacket 6 is heated by engine exhaust in an exchanger 8 and is conveyed by a feed pipe 10 to means 10a heated by the producer 11 ; this means may be a jacket in the producer body or tubes arranged as described in Specification 579,967, [Group XII]. The water then passes through a steam generator 13 having superheater tubes, through final superheater tubes 13b in an exchanger 14 heated by gases leaving the producer at 14a, and through a pipe 15 to the turbine 2. A branch pipe 10c leads heated feed water to an auxiliary steam generator 16 heated by gases from the exchanger 14 through a pipe 16a ; steam from the generator 16 is conveyed by a pipe 16b to the main generator 13 or to first-stage 'superheater tubes therein, while the gas leaving the generator 16 is conveyed to the engine 1 through cleaners &c. 18 (for example, electrostatic precipitators) by a Rootes blower 17. Some of the gas is tapped off at 17b to gas burners in the steam generator 13. The engine is a high-compression type similar' to a Diesel engine and using spark or oil-jet ignition when working on gas. Engine exhaust from the exchanger 8 is conveyed by pipe 20 to a jet 21 for creating a draught in the chimney 22 of the generator 13. An evaporator 23 in the chimney is supplied with water through an exchanger heated by flue gases at 27, and steam from the evaporator is'led to an injector 30 inducing a supply of air and steam to the producer at 32. Air supplied to the steam generator 13 by a pipe 33b may be heated in an exchanger 33 by gases in the chimney 22, and some of this air may also be conveyed at 31a to the producer. In a modification, Fig. 2, the gas producer 11a is structurally combined with the steam generator 13a. Coal or other fuel is fed from a hopper 43 on to a travelling grate 41 passing through the furnace chamber of the steam generator. The fuel is here deprived of most of its volatile constitutents and is delivered to the producer 11a, which may be of the kind described in Specification 579,967, [Group XII], the gas collected at 48 passing through tubes 49 to a collecting belt 51 and thence mainly to the engine and partly also to gas burners 53 in the furnace chamber 13a. The steam generator may comprise drums 34, 35, 36 connected by tubes 37, 38, and superheater tubes 39. In an alternative form, Fig. 2a, the grate 41a passes through a distillation chamber 57, where it is subjected to the heat of furnace gases led from the furnace chamber 13b by a conduit 56 as described in Specification 581,692, [Group XII], the distillates being led through a conduit 58 to the producer. Water tubes 53 from the steam-generator drum 35a are connected to a drum 54 restricting the passage between the chamber 57 and the furnace chamber 13b, and steam or gas nozzles 60 prevent the passage of furnace gases into the chamber 57. In a further form of the producer, Fig. 3, there is no preliminary partial combustion of the coal on the grate of a steam generator. Coal is fed by a grate 41b in a sloping distillation chamber 66, the double walls of which provide a space into which gas from the outlet 51a of the producer is injected through a pipe 51b. The injector nozzle 68 is supplied with exhaust gas from the engine, or with steam or air or furnace gas, and the mixture passes through inlets 71 and through the fuel on the grate. The carbonised coal is compressed into pellets by rollers 72 and falls over a deflector 73 into the producer. The distillates pass through a hollow rotating water-jacketed column 63 carrying fuel-distributing arms 64 and are forced through the column by an injector supplied with gas from the pipe 76. The distillates enter the fuel bed below its surface in order to heat them for removal of tarry constituents, as described in Specification 579,967, [Group XII], and pass to the outlet belt 51a. Specifications 168,705, 169,275, [both in Class 110 (iii)], 375,597 and 581,694, [Group XII], also are referred to.