The effect of dust retention on pressure drop in a high velocity pulse-jet fabric filter

Abstract

Pulse-jet fabric filters exhibit abnormally high pressure drops when operated at higher than normal superficial filtration velocities. The causes of high pressure drop are investigated for a pilot scale pulse-jet filter collecting fly ash at 50, 75, 100, 125 and 150 mm/s filtration velocities. The measured equilibrium pressure drops ranged from 0.35 kPa (1.4 in. H 2O) at low velocity to 10.2 kPa (40.8 in. H 2O) at high velocity. Retention of a large mass of dust on the fabric was found to have a significant effect on equilibrium pressure drop at all the tested filtration velocities. The dust deposit's distribution, total mass, and specific resistance ( K 2) all remained essentially constant at lower filtration velocities, but changed dramatically at the highest test velocity. At the 150 mm/s velocity the total dust mass doubled, the dust distribution equalized over the surface of each bag, and K 2 increased by a factor of 4.7.