Effects of temperature, dust concentration, and filtration superficial velocity on the loading behavior and dust cakes of ceramic candle filters during hot gas filtration
Journal
Separation and Purification Technology
Journal Volume
198
Pages
146-154
Date Issued
2018
Author(s)
Lin, J.C.-T.
Hsiao, T.-C.
Hsiau, S.-S.
Chen, D.-R.
Chen, Y.-K.
Abstract
Ceramic candle filters (CFs) are commonly used in power generation processes because of their ability for durable operation at high temperatures. Two ceramic CFs were experimentally and theoretically evaluated in this study, one composed of mullite (30–20) and the other composed of alumina and silicon carbide (F-40), representing filters with high and low collection efficiency for conventional and advanced power generation. The effects of three critical parameters in CF operation (temperature, dust concentration, and filtration superficial velocity) on two performance measures (filter loading behavior and dust cake) were carefully investigated. The revised Endo's expression was used to evaluate the resistance (αc) and porosity (ε) of dust cakes that formed on a cylindrical CF. An analysis of pressure drops for both CFs and dust cakes revealed that the pressure drops increased with the operation temperature, which was solely due to the increase in air viscosity. However, the resistance and porosity of the dust cakes were still affected by the filtration temperature, even when the influence of temperature on the gas viscosity and volumetric flow rate was considered. Between 473 and 573 K, the overall steady-state αc and ε of the dust cakes changed markedly for both CFs. Moreover, for the low-efficiency CF (F-40), improvement in the collection efficiency with the temperature depends on improved diffusional effects and may influence the corresponding dust cake structures.
SDGs
Publisher
Elsevier B.V.
Type
journal article