In‐situ leakage detection of single bag filter in baghouse based on the resistance change of conductive polymer fibers

Abstract

Baghouse is effective for controlling the particles emitted from industrial production, and the in‐situ leakage detection of a single bag filter is essential for maintaining the high filtration performance of the whole baghouse. In the present study, the changes of PM emission concentration induced by the leakage of the bag filter materials was studied. The results showed that the concentration of particles in the size range of 20–1000 nm significantly increased when the bag filter sample had three holes with a diameter of ~500 μm. In order to prevent the loss induced by the leakage of bag filter, a resistance sensing method was developed to detect the early leakage of single bag filter. The effectiveness of proposed sensing method was verified by detecting the leakage of polymethyl methacrylate (PMMA) bag filter. A sensing grid made of PMMA conductive threads was embedded in the PMMA bag filter, and the resistance change (ΔR) induced by the broken of sensing grid was used as sensing signal. The ΔR of sensing grid was 3.24, 3.31, and 3.05 Ω, respectively, when the bag filter failed due to the mechanical stress, chemical corrosion, and thermal erosion. Moreover, a model was proposed to predict the numbers of broken conductive PMMA threads that could indicate the damage area of the failed bag filter.