Cleaning hot gas filters by water injection - causing pressure wave on clean gas side to release filter cake

摘要

Process involves creating a pressure surge on the clean gas side. This is done by releasing a charge into the clean gas space which causes a sudden and considerable increase in volume. The pressure pulse thereby created acts on the clean side of the filter medium and causes the cake to drop off. A suitable charge is a small volume of liquid which will flash off under the conditions in the filter. It is heated to its b.pt. and released under pressure. Water is esp. suitable for hot gases over 100 degrees C. Other suitable materials are propellents, gum powder, self igniting materials, detonators etc. Conventional techniques having compressed air are unsuitable because they tend to cause thermal shock on the filter. The system described avoids this. It does not require large vols. of air to be heated up and needs no additional complicated equipment.