| 摘要 |
PURPOSE:To enable to prevent production of smoke under any state of combustion, by providing a means for detecting the color of exhaust gas discharged from a boiler, and increasing air supply automatically when a signal indicating that the color of exhaust gas is darkened is given. CONSTITUTION:An automatic combustion controlling device for boiler, shown in the drawing, comprises a divider 10 to which are given outputs of an air-flow detector 09, air-fuel ratio adjustor 11 and air-fuel ratio generator 17, an adder-subtracter 12 to which is given the output of the divider 10, etc., and it operates indirectly to prevent production of smoke by controlling an air controlling unit 14 on the basis of the fuel-air ratio. Here, a circuit 100 for controlling the color of exhaust gas is constituted by a smoke-color detector 21, adder-subtracter 22, smoke-color setter 23, proportioning means 24 limiter 25, and its output is given to an air-fuel ratio adjusting line via an adder-subtracter 26. With such an arrangement, production of smoke is prevented by controlling the unit 14 to increase the air-flow rate when the density of smoke is increased to a level higher than a predetermined value. |
