PFB Coal Fired Combined Cycle Development Program. Advanced Cleanup Device Performance Design Report (Task 4.3). Volume B. Air Shield Cyclone Evaluation

摘要

The purpose of this experimental program was to obtain performance data on a twelve-inch diameter model of the air-shield cyclone. The efficiency results were extremely high, independent of whether or not the air shield feature was operative. In particular, substantially higher performance was obtained than reported in the literature for a Stairmand high-flow cyclone design, which has some features in common with the model. The reason for the high performance without the air shield is attributed to a strong space charge effect which can be a much stronger influence when there is no air shield. Overall efficiency, fractional efficiency and pressure loss measurements have been obtained during cold-flow testing of the air-shield cyclone model and also with the unit arranged to simulate a more conventional cyclone design. Pressurized fluidized bed flyash and powdered nickel, both having a mass mean particle size of about 2 mu m, were used as test dusts. Inertial forces appeared to dominate the performance of the air-shield cyclone over the entire range of flow rates tested. Fractional efficiency results correlated well with the inertial parameter, psi. Air-shield cyclone performance data confirmed earlier projections that efficiency would be an-order-of-magnitude better than published results on conventional cyclones. (ERA citation 05:032192)