Patent GB-288721-A (GB)
Title: Improvements in and relating to liquid or pulverised fuel burners
IPC: F23D11/04
Filed: 1927-01-13
Abstract: 288,721. Bentley, H. Jan. 13, 1927. Spray and pulverulentfuel burners; electrically controlling fuel and air supplies; liquid fuel supply; burners, arrangements of.- In a heavy fuel burner which is automatically stopped or started in accordance with the conditions in the unit being heated the pressure developed by the electrically driven fan or blower supplying the combustion air is utilized at starting to deliver a predetermined amount of petrol or other liquid fuel to a pilot or starting burner for ignition purposes. Fig. 3 shows a liquid fuel burner apparatus which is suitable for firing a steam generator for motor vehicles and comprises a high speed electric motor 4 having a hollow armature shaft 4<a> carrying a centrifugal fan 5 and an atomizer 6. Liquid fuel is supplied to the atomizer 6 through a pipe 7 arranged in the shaft 4<a> and fitted with a valve 8<a> which is opened, electrically against resistance of a spring 8<b> by a solenoid 9. The atomizer preferably consists of a cone 6<a> formed with apertures 6<c> through which part of the oil is fed to a surrounding cone 6b. The cones are formed with air inlet apertures 6<d>, 6e and may have their outer edges serrated. The fan 5 delivers air, which may be preheated, to the atomizer through conduits 2b. At starting the air pressure exerted by the fan is communicated to a chamber 14, Fig. 7, by a pipe connecting an inlet 14<a> to a vent 2<c> on the fan casing. The chamber 14 becomes filled with petrol or other inflammable liquid when the fan is at rest from a float chamber 13 through a passage fitted with a non-return valve 14<a>. The air pressure in the chamber 14 closes the valve 14<a> and forces the petrol through a pipe 12 to a burner tray 10<a> where ignition is effected by a sparking plug 11, thereby creating a flame directed across the path of the fuel from the atomizer 6. The burner is started by closing the switch G, Fig. 11, of an accumulator E or other source of electricity to supply current through a circuit breaker 18<a> to the motor 4, the solenoid 9, and an induction coil F connected to the sparking plug 11. After an interval during which the petrol forced to the tray 10<a> becomes ignited the air pressure of the fan is sufficient to operate a diaphragm with a casing 18 against spring pressure and break the primary circuit of the coil F. If the pressure in the steam generator being heated exceeds a predetermined amount a pressure-sensitive device C operates to communicate pressure from a pipe C<2> through a pipe C<3> to the diaphragm chamber of the circuit breaker 18<a> and thereby stops the motor 4 and closes the valve 8<a>. When the pressure subsequently has fallen to below the predetermined amount the device C operates to relieve the pressure in .the diaphragm chamber and to remake the circuits to the motor solenoid and induction coil. The device 18<a> may alternatively be arranged to reduce the speed of the: motor previous to or instead of stopping it. Fig. 13 shows a burner apparatus in which a pulverized fuel burner C comprising an electrically driven rotating conical cup 6<f> is ignited by a pilot burner B constructed similarly to that previously described. The feed through the stationary or rotating pulverized fuel supply pipe may be subjected to the control of a sensitive element while the burner B, once lit, burns continuously. A liquid fuel burner may be substituted for the pulverulent fuel burner C.