97/05092 Improved high temperature resistant SiC filter elements: Walch, A. et al. Proc. Annu. Int. Pittsburgh Coal Conf., 1996, 13th, (1), 349–356

Abstract

High temperature resistant porous ceramics are of major importance in hot gas filtration to separate particles from process and flue gases in temperature ranges of 250 C to 850 C. DIA-SCHUMALITH{reg_sign} filter elements, produced by Schumacher Umwelt- und Trenntechnik GmbH, Crailsheim, Germany for over 10 years, are clay bonded, silicon carbide (SiC) filter elements which are used successfully in hot gas applications. DIA-SCHUMALITH fulfills the critical demands of utmost filtration efficiency, low cost, and long-term durability. These membrane coated, porous filter elements are exposed to complex and aggressive gas mixtures in oxidizing or reducing atmospheres at pressures up to 30 bar and as such require excellent material properties to survive. From an environmental point of view it is important to provide a filtration media which will ensure excellent filtration efficiency with particulate removal of <3 mg/m{sub N}{sup 3} (3 ppm) at low residual pressure drops and high specific mass flow rates to yield a reasonable low cost filtration system. Hot gas filtration, successfully used in advanced clean coal technologies such as PFBC and IGCC processes, allows much higher thermodynamic efficiencies. Other advantageous and successful applications of hot gas filters are the removal of ceramic powders, pigments or catalysts from processmore » gas streams, as well as flue gas filtration in pyrolysis processes and municipal waste incinerators. Technical requirements for high temperature resistance combined with long term durability and material reliability are constantly increasing. These requirements necessitate continuous material improvements as well as ongoing test procedure developments. The results of these material developments concerning thermal and mechanical properties will be presented in this paper.« less