GB880141A - Improvements relating to liquid fuel fired boilers - Google Patents

Abstract

880,141. Oil burner control systems. FUEL FIRING Ltd., and WEBB, E. F. D. Oct. 28, 1957 [July 27, 1956], No. 23358/56. Class 75(1) A liquid fuel firing apparatus especially for boilers comprises two or more superposed tiers of burners and means for producing a difference between the rate of firing of one or more of the upper burners and that of one or more of the lower burners whilst maintaining the same aggregate rate of firing for all the burners. The means may comprise a controller actuated by the temperature or pressure of the fluid being heated, which is connected directly to a valve controlling one of the tiers of burners and through a reversing relay to a valve controlling the other tier. In the arrangement shown, the burners of the upper tier 2 are connected by a common supply line 6 to a valve 5, the burners of a middle tier 3 are connected by a common supply line 9 to a valve 8 and the burners of the lower tier 4 are connected by a common supply line 12 to a valve 11, all the valves being fed by a common supply line 14. The valve 5 is controlled by an averaging relay 15 in accordance with impulses received from an automatic or manual composition controller 17 and an automatic temperature controller 18 responsive to the superheat temperature of the steam leaving the boiler. The valve 8 is controlled directly by the controller 17 and the valve 11 is controlled by an averaging relay 16 in accordance with impulses received from the controller 17 directly and the controller 18 via a reversing relay 20. The rates of firing of the upper and lower tiers are therefore varied in opposite senses in response to the controller 18. A similar system for burners of the return flow type is described.