Rigid Ceramic Filters for Hot Gas Cleaning

Abstract

Rigid ceramic filters have emerged in the last decade as the most promising technology for particulate removal from process gases at temperatures up to 1000ºC. Granular and fibrous forms of media have been developed and both are commonly employed in the form of cylindrical “candles” which are periodically cleaned by application of a reverse gas pulse. Research has focused on this cleaning process, which governs the long-term performance of the filter. The problem is two-fold: to develop an expression for the intrinsic dust cake “detachment stress” from knowledge of the dust particle properties and cake structure, and to model the propagation of the cleaning pulse which is applied to remove it. The results of this research are summarized and experimental methods for investigation of filter cleaning briefly described. The implications for design and further development of ceramic filters are discussed.