| 摘要 |
PURPOSE:To prevent combustion with excessive air or incomplete combustion by controlling the feed rate of air for combustion on the basis of the concentration of CO when CO is found in the waste gas, and on the basis of O2 when CO is not found in the waste gas. CONSTITUTION:Since CO rarely occurs in an ordinary combustion in a combustion furnace 4, a signal representative of the concentration of O2 from an O2 meter 5 in a waste gas pipe 3 is input into a deviation detector 10 via a regulator 9. In the detector 10, the mentioned signal is compared with a signal representative of an object concentration of O2 to compute a deviation. A signal representative of the deviation is converted to a signal representative of flow rate of air in a conventer 11 by using a predetermined conversion factor with respect to deviation in O2 concentration and flow rate of air. With a signal from the converter 11, a control valve 8 for controlling the feed rate of air for combustion is operated. When abnormal combustion or combustion with a low concentration of O2 takes place, the concentration of CO is detected by a CO meter 6. Then, a switch 13 is shifted to a contact b by an output from a CO generation detector 12, and an output from the detector 12 is given to the control valve 8 through an air converter 14 to control the valve 8. |
