Study of filter cake formation mechanisms during tangential filtration of dust-laden gases at high temperature

• Published in: Powder technology 2000-11, Vol.113 (1), p.197-204
• Main Authors: Ferrer, Y, Templier, J.C, Gonthier, Y, Bernis, A
• Format: Article
• Language: English
• Subjects: Alumina membranes; Applied sciences; Atmospheric pollution; Chemical engineering; Dust-laden gases; Exact sciences and technology; General processes of purification and dust removal; High temperature; Membrane separation (reverse osmosis, dialysis...); Pollution; Prevention and purification methods
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/S0032-5910(00)00343-0

A study was made of the possibility of filtering gases using tubular alumina membranes, with a tangential configuration and at high temperature. We verified that this process has, in the 700–800°C temperature range, the same ability to limit cake thickness as at ambient temperature. Under the action of tangential circulation, particle segregation occurs. This favors deposition of the smallest particles and leads to greater or lesser reduction in permeability of the filter cakes formed, depending on aerodynamic conditions. The degree of segregation can be estimated by calculation of a critical particle diameter. A large part of the mass flow of deposition arises from the diffusion and turbulent impact mechanisms, and not only from the phenomenon of suction at the wall due to filtration. From these elements and from the determination of the shearing stresses which characterize the stationary regime, it is possible to predict the development of head loss engendered by the filter cake during filtration.