DETECTION OF BACKWASHING ABNORMALITY OF BAG FILTER

PURPOSE:To reduce an attaching space and to achieve the miniaturization and cost reduction of an apparatus by accurately grasping any cause of the operation inferiority of a backwashing damper used in the backwashing of a bag filter and detecting the inferior state of the damper by one detector. CONSTITUTION:A pressure detector 13 is provided to detect the pressure of backwashing gas at the time of backwashing and the pressure of the backwashing gas changes corresponding to the opening and closing signal of a backwashing damper 10 and, when there is regularity in the change of the pressure, it is judged that the backwashing damper is normally operated and, when the pressure of the backwashing gas does not change corresponding to the opening and closing signal of the backwashing damper 10 to continuously rise or fall, it is judged that the operation of the backwashing damper is inferior.