Microstructure analysis of residual dust cake for ceramic filter during cycles

Key words:  ceramic filter  residual dust cake  porosity  microstructure analysis

Abstract:

The change laws of thickness, porosity, median particle diameter and other parameters of the residual dust cake on the ceramic filter surface after some cycles were measured by microstructure analysis method of the ceramic filter. The variation of the residual dust cake with the cycle times was analyzed. The results show that there exists a serious patch cleaning phenomenon in the initial period of the filtration cycle due to the uneven distribution of the microstructure parameters for the filter membrane. With the increase of cycle times, some dust particles deposit within the filter medium especially in some larger pores, which causes patch cleaning alleviate, and the thickness distribution of the residual dust cake become uniform. The porosity distributes non uniformly along the residual dust cake depth and the inside one lower than the surface. With the cycle times increasing, the porosity of the part of residual dust cake near filter element decreases, which should be responsible for the residual pressure drop increasing.