Contribution to improvement of cleaning efficiency of pulse-jet fabric filters

Uniform distribution of compressed air in a blow pipe is an important consideration in the efficient use of compressed air for pulse-jet cleaning of fabric filters. It influences the consumption of compressed air, operational costs for filtration, and particle penetration through the filter. This paper reviews recent developments in this area. A formula for compressed air consumption per pressure pulse is derived, based on the pressure drop in the air vessel and polytropic change in the air state in the vessel during the pulse with the coefficient near to adiabatic change. A criterion for uniform distribution of compressed air in the blow tube is derived, based on the constant flow momentum of jets from nozzles in the blow pipe. By analysing the measured pressures along different blow tubes, a procedure for designing the diameter of the holes in the blow pipe is proposed, using only the inner diameter of the blow pipe and the number and nominal diameter of the cylindrical holes. A simplified mathematical model for the distribution of compressed air in the blow tube is described. Very good agreement between calculated and measured values has been achieved.