GB405608A - Improvements in or relating to combustion control apparatus - Google Patents

Abstract

405,608. Regulating draught in furnaces. GAS LIGHT & COKE CO., Ltd., DIETERICHS, W., and BROOKBANK, T. A., 84, Horseferry Road, London. July 5, 1932, No. 19032. [Class 51 (i).] A damper 17 in the flue of a fluid fuel burning device is operated by a diaphragm 3 deflected by variations in the air or fluid fuel flow to a burner so that the free cross sectional area of the flue is maintained proportional or approximately proportional to the rate of consumption of fuel. The damper is positively connected to a diaphragm 3 at one side of which is an enclosed space 21 in communication, at a point on the burner side of any valves or taps, with a pipe feeding fuel or air to the burners of the apparatus. The diaphragm 3 conveniently of leather is reinforced by metallic washers 6, 7 and clamped at its edges between the parts 1 and 2 of the diaphragm casing one side of which is adapted to be connected to the fuel or air pipe by way of the inlet 22. A rod 8 carrying a rack 14 engaging with a geared segment 15 on the damper spindle is bolted at one end to the diaphragm and at the other is guided between adjustable rollers 9, 10. The rod and segment are enclosed in a casing 13 bolted to the flue 23 and to the casing of the diaphragm. In one form, Fig. 1, the diaphragm is loaded by a helical spring 20 and the flue is enlarged above and below the damper by an outward curvature as shown at 25, 26 so that as the damper which is of circular form moves through its range of 90‹, the area of flue opening is approximately proportional to the rate of consumption of fuel. In a modification Fig. 4, a similar result is obtained using a straight flue 30, the damper being of elliptical form and having a range of 45‹ and the diaphragm being loaded by a conical spring 20<1>. In this form the damper is fully closed at an angle of 45‹ to the axis of the flue.