Dust Cake Compression Research In Filter Process With Embedding Method

Nowadays, the pollution of inhalable particles is becoming moreimportant in environment research. Filter bag is a clean, highly efficientdedust method, which is also prevalent. However, some mechanism problemsin filter process are not clear. Dust cake compression is just one of theseproblems. The article gives an embedding method to directly observe andanalyze the dust cake inner structure. Based on the embedding method, ahalf-experiential model is proposed to describe the dynamic process of thedust cake construction.Dust cake embedding uses certain resin to soak into the dust cake sample,while not destroy the cake structure. In proper environment, the resin willbecome solid and the dust cake is embedded. Then the solid cake can beobserved under SEM after following final disposal. Through the images of thecake sample, the porosity curve in the sample can be obtained. The porositiesin the different positions of the cake are almost near a certain value, whilesome periodical fluctuations exist.In filtration process experiments, certain periodical jumps are observedin the pressure drop curves. It proves that the dust cake compression doesexist in the cake structure. These pressure jumps will occur after theaccumulation of minor fluctuations. Comparing several pressure drop curves,concentration of particles and growth speed of dust cake directly influence theheight of dust cake and the porosity, then influence the pressure drop. Withproper hypothesis and experiment data, a half-experiential model can be usedto explain the dynamic porosity distribution in the dust cake. The model canalso calculate the pressure drop curve and pressure jumps.