"REDUCED ENTRAIN MENT PRECIPITATOR

THE REDUCED ENTRAINMENT PRECIPATATOR WILL HAVE IMPROVED COL-LECTION EFFICIENCY FOR DUSTS HAVING EITHER HIGH OR LOW ELEC-TRICAL RESISTIVITIES. THIS OBJECTIVE IS ACCOMPLISHED BY PRO-VIDING A POROUS, FABRIC COLLECTING SURFACE. A SMALL PORTION (TYPICALLY LESS THAN 20%) OF THE DIRTY GAS STREAM IS DRAWN THROUGH THE COLLECTED DUST CAKE AND THE POROUS COLLECTING PLATE BY A SEPARATE FAN. THIS SMALL FLOW THROUGH THE DUST PROVIDES AN AERODYNAMIC FORCE TO REDUCE RE-ENTRAINMENT OF THE DUST. TYPICAL FABRIC FILTER DUST CAKE PRESSURE DROPS, THE DUST RETAINING FORCE, CAN BE ORDERS OF MAGNITUDE LARGER THAN THE REENTRAINING FORCE, THE DYNAMIC HEAD OF THE FLOWING STREAM THE PROVISION OF A SIGNIFICANT AERODYNAMIC FORCE TO COUNTER-ACT REENTRAINMENT HAS AT LEAST TWO POTENTIAL BENEFITS: (1) HIGHER PRECIPITATION THROUGH-PUT VELOCITIES MAY BE USED THUS REDUCING THE SIZE OF THE PRECIPITATOR. (2) IN A CONVENTIONAL PRECIPITATOR, DUST RETENTION FORCES ARE PROVIDEDBY CORONA CURRENT FOR DUST RETENTION IN TURN ELIMINATES THE DEPENCENCE OF THE PROCESS ON DUST RESISTIVITYEITHER HIGH OR LOW