GB179952A - An improved method of regulating combustion in boiler furnaces and means therefor - Google Patents

Abstract

179,952. Smoot, C. H. May 11, 1921, [Convention date]. Air-supply, regulating. -Combustion in a steam-boiler furnace is regulated by varying the amount of air supplied to the furnace by a fan in accordance with changes in the pressure of steam in the boiler and in the pressure of the air supply. The steam pressure in the boiler 2, Fig. 1, acts upon a piston 9 and tends to lift a constant load 17 upon a diaphragm 15 mounted in the chamber 18 and is assisted by the differential pressure of the air supplied from the blast conduit 7 through the pipes 20 and 19 to the upper and lower sides of the diaphragm 15. Upward move. ment of the diaphragm actuates, through relay apparatus 13, the valve 6 controlling the supply of steam to the engine 3 driving the fan 4 supplying air beneath the grate 1. In the modification shown in Fig. 3, air-supply and exhaust fans 3, 4 are controlled by varying the steam supplied through the valve 34 to the fan engines 5, 6 in accordance with the changes in boiler pressure and the difference in pressure at the fans. Steam pressure from the boiler acts through the pipe 11 upon a diaphragm 9 loaded by the spring 13 and is assisted by the differential air pressure acting on the diaphragm 23 connected by the lever 18 and link 17 to the diaphragm 9. Down. ward movement of the diaphragm 23 caused by increase in the differential pressure on the diaphragm actuates, through the rod 42 and arm 29, a valve 28 reducing the pressure of steam above a differential piston 26, due to the effect of a throttling-valve 48, and causing the piston to actuate the link 30, lever 31 and rod 33 and close the valve 34 supplying steam to the fans. The differential piston 26 is connected to the rod 42 through a dashpot 39.