Properties of Ceramic Candle Filters

Coal-fired Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) systems require ceramic candle filter elements which can withstand the mechanical, thermal, and chemical environment of hot gas cleanup applications. These systems demand filter elements to sustain the thermal stresses of normal operations (pulse cleaning), of start-up and shut-down conditions, and of unanticipated process upsets such as excessive ash accumulation without catastrophic failure. The filter elements must also survive the mechanical loads associated with handling and assembly, normal operation, and process upsets. Objectives of the test program at Southern Research are as follows: (1) Provide material characterization to develop an understanding of the physical, mechanical, and thermal behavior of hot gas filter materials. (2) Develop a material property data base from which the behavior of materials in the hot gas cleanup environment may be predicted. (3) Perform testing and analysis of filter elements after exposure to actual operating conditions to determine the effects of the thermal and chemical environments in hot gas filtration on material properties. (4) Explore the glass-like nature of the matrix material