Pore structure and permeability of an alumina fiber filter membrane for hot gas filtration

The pore structure and permeability of an alumina-fiber-based hot gas filter membrane containing an acid phosphate binder were characterized using capillary flow porometry. The smallest pore diameter was 1.24 +/- 0.06 mum; the largest pore diameter (bubble point pore diameter) was 23 +/- 1 mum. The pore size distribution was narrow, with almost all pores ranging from 2 to 4 mum, and the mean flow pore size 2.6 +/- 0.1 mum. The Darcy permeability constant for air through the membrane was (114 +/- 6) x 10(-9) cm(2).