A CERAMIC MATERIAL AND PROCESS FOR USE IN MONOLITHIC CERAMIC CROSS-FLOW FILTERS

CERAMIC CROSS-FLOW FILTERS HAVE BEEN DESIGNED TO PROVIDE HIGH TEMPERATURE, HIGH PRESSURE REMOVAL OF PARTICULATES FROM HOT GAS STREAMS IN COAL FUELED POWER SYSTEMS, WITH THE BENEFIT OF HIGH SURFACE AREA PER UNIT VOLUME. HOWEVER, FURTHER CERAMIC TECHNOLOGY IS NEEDED ON CROSS-FLOW FILTERS TO IMPROVE BOTH EFFECTIVENESS AND RELIABILITY. AN IMPORTANT NEED HAS BEEN IDENTIFIED AS A ONE-PIECE MONOLITHIC CERAMIC CROSS-FLOW FILTER, RATHER THAN THE PRESENT SEGMENTED FILTER THAT HAS BEEN KNOWN TO DELAMINATE IN SERVICE. THIS DELAMINATION ALLOWS PARTICULATES TO BYPASS THE FILTER, WHICH COULD LEAD TO COSTLY DAMAGE TO DOWNSTREAM TURBINES AND SUBSEQUENT FAILURE TO MEET ENVIRONMENTAL REGULATIONS PERTAINING TO STACK GAS EMISSIONS. CURRENT CERAMIC TECHNOLOGY HAS PROVED INCAPABLE OF FORMING A COMPLEX ONE-PIECE SHAPE OF THIS NATURE WITH AN ACCEPTABLE PERMEABLE, POROUS CERAMIC MATERIAL. A UNIQUE AND PROPRIETARY INJECTION MOLD CERAMIC FORMING PROCESS HAS BEEN USED FOR YEARS TO PRODUCE COMPLEX ONE PIECE MONOLITHIC SHAPES COMMERCIALLY, BUT OF A NON-PERMEABLE NATURE. THE DEVELOPMENT OF A PERMEABLE CERAMIC COMPOSITION FOR THIS PROCESS REPRESENTS A SIGNIFICANT EFFORT. IN PHASE I, THE AIM IS TO DEMONSTRATE THE FEASIBILITY OF A NOVEL TECHNOLOGY WHERE A PERMEABLE, POROUS CERAMIC MATERIAL IS FORMED WITH THIS PROCESS, TARGETED TO MEET THE FILTRATION AND ENVIRONMENTAL REQUIREMENTS OF CROSS-FLOW FILTERS. WITH THIS MATERIAL AND PROCESS, A MUCH MORE RELIABLE, EFFECTIVE MONOLITHIC CERAMIC CROSS-FLOW FILTER CAN EVOLVE.