Fabrication of cordierite filter by in-situ solidification for high temperature dust collection

Cordierite ceramic filters have been shown a potential candidate for a high temperature dust collection, owing to its very low thermal expansion coefficient characteristic as an attribute of excellent thermal shock resistance. It is preferable that a design of porous cordierite filter should have low pressure drop with high permeability while keeping the structural integrity. This study describes a simple and direct approach for fabricating a porous cordierite filter with honeycomb-type structure by introducing various non-through holes into mechanically foamed slurry, which is subsequently in-situ solidified by polymerization reaction. The gelcasting cordierite-based slurry was mechanically foamed in nitrogen-filled chamber. The resulting foamed slurry was cast directly into circular molds equipped with a cover having different number of pins. The gelled-bodies were carefully dried at 25 °C with a controlled humidity, followed by sintering under optimized condition. The dust collection performance, pressure drop, and gas permeability were evaluated as a function of the number of non-through holes in porous cordierite. Based on the results of the tests, the holey porous cordierite filter offered a better filter design for dust collection application.

Fig. 1. Mold assembly for porous cordierite body with non-through holes. Teflon mold (A, B, D), cover-with- pins mold (A, B), cross-section with non-through holes (C).Figure optionsDownload as PowerPoint slide