| 摘要 |
PURPOSE:To properly replace cadmium sulfide cells for prevention and maintenance from deterioration, by taking out the deterioration of a flame detecting cadmium sulfide cell of which resistance value is changed in accordance with the irradiation of light as a signal. CONSTITUTION:A control circuit 9 compares the resistance value of the cadmium sulfide cell 1 which is changed in accordance with the intensity of illumination in a furnace at the time of preparative operation of a boiler with a reference resistance value corresponding to the darkness in the furnace during the suspension of fuel feeding, and when the detected resistance value is less than the reference resistance value, discriminates that the cell 1 is deteriorated. During the period that a fuel feeding suspending signal 10 is applied from a control circuit C12, the control circuit 9 outputs a signal indicating the deterioration of the cell 1. In the flame detector to detect the existence of flames in accordance with the change of the resistance value of the cell 1 through a control circuit A5, the cadmium sulfide cells the be properly replaced in order to prevent and maintain them from deterioration. |
