BREAKAGE DETECTOR FOR FILTER CLOTH IN BAG FILTER

PURPOSE:To find early a damage on a filter cloth and contrive to enhance speediness of replacement, by a method wherein a detector for gas permeability of a filter cloth is provided in proximity to the surface of the filter cloth, and is moved relatively to the surface of the filter cloth. CONSTITUTION:A sound-detecting suction nozzle 1 is provided in contact with the filter cloth surface R of the bag filter, and is moved on the surface R in the manner of a wiper. A gas sucked through the nozzle 1 is sucked away by a blower 8 through an arm 2, a rotary pipe 3 and a conduit 4. In this case, the quantity of the sucked gas passing through a flowmeter 5 is set to be constant by a flow control valve 7, the pressure required for obtaining the constant flow rate is measured by a pressure detector 5, and the pressure value is indicated on a pressure recorder 9. The recorder 9 is provided with alarm points indicating the upper and lower limits of pressure value, and when the pressure is lowered to or below a predetermined value, it is judged that the filter cloth is broken, and when the pressure is raised it is judged that the gas permeability of the filter cloth is lowered.