GB283522A - Improvements relating to furnaces - Google Patents

Abstract

283,522. Gordon & Co., Ltd., J., (Assignees of Peebles, T. A.). Jan. 12, 1927, [Convention date]. Regulating combustion. - In furnaces heated by gaseous fuel from a fluctuating source of supply such as blast furnaces and where an auxiliary source of pulverized or other fuel supply is employed to make up for any deficiency of gaseous fuel, means are provided whereby the auxiliary fuel-feeding mechanism is controlled automatically by the pressure in the furnace. In cases where the gas is supplied from a common main to a battery of furnaces, one or more furnaces are shut down or brought into operation successively as the gas supply varies. Fig. 1 shows the invention applied to a boiler furnace. Blast furnace gas and air are supplied to the burner 7 from the main 8 and fan 10 respectively, the gas supply being controlled by a valve 12 actuated by the pressure in the main 8 through the regulator 13 and the air supply being controlled by a valve 15 actuated by the differential pressure existing between the gas and air supply transmitted through the pipes 17 and regulator 16. A reduction of the gas supply causes a closing of the gas and air supply valves and a diminution of steam pressure which through the pipe 60 causes the movable frame of the master regulator 40 to be lowered and through the cable 41 to operate a switch 42 controlling the motor of the pulverizer 45 so as to supply fuel to the burner 55. In the event of the gas supply being increased, the pressure in the furnace combustion chamber rises and is communicated through a pipe 20<1> to a regulator 20 which moves upwardly and through the rod 22 actuates the counterweighted damper 19, the operating lever 23 of which is connected to the rod 22 by a pin-andslot connection to allow continued upward movement of the regulator 20 after the damper has been fully opened. The continued upward movement of the regulator 20 actuates through a cable 29 a lever 30 connected to a, link 32 engaging by pin-and-slot connection with a lever 35. The latter actuates through cables 47, 51 the valve arms 48, 52 so as to regulate the associated valves to reduce the supply of fuel and air to the burner 55. Should the gas supply be sufficient to shut off the supply of auxiliary fuel the steam pressure will be sufficient to operate the master regulator 40 and cause the operation of the switch 42 to shut down the pulverizer motor. Where a battery of boiler furnaces are supplied from the main 8, the automatically operated gas valves 12 cut out or put into operation one or more furnaces in succession.