USING CFD TO REDUCE COMMISSIONING TIME FOR ELECTROSTATIC PRECIPITATORS

摘要: ABSTRACT The standard procedure for the setup of airflow distribution plates within electrostatic precipitators (ESP’s) typically requires a time consuming trial and error method based on repeated field measurement, followed by production interruptions adjustment. During recent Pinjarra Efficiency Upgrade project, Alcoa Hatch utilized CFD analysis inlet flow system in two new alumina calciner ESP’s to eliminate need adjustment, thereby significantly shortening commissioning costly delays. NOMENCLATURE C c contraction coefficient P pressure K momentum loss V velocity e porosity ρ density INTRODUCTION A upgrade project at Alcoa’s Refinery has targeted wide range process environmental improvements including addition as preferred option gas cleaning. made provision total 4 units be installed operational November 2006. are well accepted widely used air pollution control due reasonable collection efficiency, low pressure-drop, capital operating costs. performance modern would expected better than 99.9% particulate removal efficiency while incurring less 100 Pa drop. Although commercially available large scale industrial cleaning exhibit slight variations design characteristics, componentry, mechanical style, all achieve quite simply use forces acting airborne solid particles promote their attraction eventual charged electrodes. Maximising migrate surfaces minimising likelihood solids re-entrainment dictates that is strongly dependent achieving uniform low-velocity gas-flow throughout main body ESP inter-electrode passages. Hence, considerable care must exercised supply ductwork conditioning upstream ESP. One an acceptable internal through “Gas Distributor Plate” (GDP) which covers complete cross section comprised array with W shaped 110 x 120 mm rectangular openings square pitch 250 mm. Additional (called “zig-zag” plates) same design, slide laterally provide local closure apertures minimum size 60 (50% normal open area). resistance GDP generally ability reduce locally effective adjustment zig-zag provides means make adjustments optimise Figure 1 shows layout typical .