GB628285A - Improvements in or relating to a burner - Google Patents

Abstract

628,285. Lighting gas burners. WHEELCO INSTRUMENTS CO. Feb. 20, 1947, No. 4980. Convention date, Aug. 13, 1941. [Classes 75(i) and 75(iii)] A gas burner 3 is provided with a safety control device including a flame electrode 2 disposed in the flame path of the burner 3 and a pilot burner 4 and connected with a switch mechanism 20 which operates when the flame circuit is completed to energize a relay 22 for opening a switch means, a second relay 12 having an operating coil 17 which, when energized by closing a starting switch 10, closes a second switch means, a supplemental switch means closed by the energization of the relay 22, and connections for operating an electrically controlled fuel valve 6 to admit fuel to the burner only when the supplemental switch means and the second mentioned switch means are closed. The burner is started by closing the push button switch 10 to energize from the mains 18, the electrically operated pilot valve 7, and the ignition transformer 5 through contacts 26, 27 of the relay 22, and at the same time coil 17 is energized to close contacts 15, 16 and 13, 14 of the relay 12. A flame appears at the pilot burner which completes the circuit of the switch 20 so that the relay 22 makes contacts 24, 25 and 27, 28, and breaks contacts 23, 24 and 26, 27. The making of contacts 24, 25 energizes the main gas valve 6 through contacts 15, 16 of the relay 12, and the burner 3 is ignited from the pilot burner 4. Upon releasing the push button 10, the transformer 5 and the valve 7 are de-energized leaving the circuit maintained by the flame from the burner 3 impinging on the rod 2. Should flame failure occur the relay 22 is de-energized to break contacts 27, 28 and 24, 25 to de-energize the main fuel supply valve 6. If a leakage path exists between the flame rod 2 and the ground of a similar resistance to that of the flame the relay 22 is held closed, and depressing the push button 10 will not start the system because the contacts 26, 27 are broken. An alarm bell 11 may be provided, which is energized when the contacts 23, 24 and 26, 27 are made, to indicate audibly that a flame failure has occurred.