Tham khảo tài liệu 'air pollution control systems for boiler and control problems_4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Sim poiPDF Mergeíand Split Unregistered Version - http WEIGHT PERCENTAGE LESS THAN STATED PARTICLE SIZE PARTICLE SIZE DISTRIBUTIONS OF PARTICULATE EMITTED FROM UNCONTROLLED POWER PLANTS PULVERIZED COAL FIRED BOILER . Army Corps of Engineers Figure 6-8. Particle size distribution curve by weight of particulate emitted from uncontrolled power efficient because the cyclone exhibits an increased collection efficiency during high gas flow and dust loading conditions while the precipitator shows and increase in collection efficiency during decreased gas flow and dust loading. The characteristics of each type of equipment compensate for the other maintaining good efficiency over a wide range of operating flows and dust loads. Cyclones are also used as pre-cleaners when large dust loads and coarse abrasive particles may affect the performance of a secondary collector. They can also be used for collection of unburned particulate for re-injection into the furnace. c. Fine particles. Where particularly fine sticky dust must be collected cyclones more than 4 to 5 feet in diameter do not perform well. The use of small diameter multicyclones produces better results but may be subject to fouling. In this type of application it is usually better to employ two large diameter cyclones in series. d. Coarse particles. when cyclones handle coarse 6-10 Simpo PDF Merge and Split Unregistered Version - http 5-815-1 AFR 19-6 IOO particle bouncing U o cr UJ INCREASING PARTICLE SIZE ZONE EDDY o s UJ tn --- ZONE OF PARTICLE EFFICIENCY DUE TO FLOCCULATION EFFECTS THEORETICAL FRACTIONAL EFFICIENCY CURVE INCREASING COLLISIONS a THEORETICAL EFFICIENCY curve __ 7ctual EFHLILI Turve OF decreased efficiency due to FLOWS AND . Army Corps of Engineers Figure 6-9. Fractional efficiency curves I00 TYPICAL MANUFACTURER S IO particle I5 DIAMETER FRACTIONAL EFFICIENCY CURVE z UI o CE UJ 0. 60 1 PRESS J f OF SURE DROP WATER IN INCHES In x V. 1 0 in 2 0 in 3 0 1
