旋/直复合流化对脱硫塔内粘壁问题的影响

采用激光相位多普勒颗粒分析仪(3D-PDA)测试了新型内旋/直复合流化方式下循环流化床烟气脱硫塔内与粘壁有关的气-液-固三相参数,试验证明:旋/直复合流化能够提高塔中下部特别是近壁处的气固切向速度及气固间相对切向滑移速度,增强扰动,同时提高脱硫塔中下部特别是近壁处的固体颗粒浓度,有利于促进液滴或含湿颗粒的高效利用和快速干燥,减轻粘壁;旋/直复合流化下液滴在塔内的分布变化也证明旋流风对促进液滴干燥、减轻粘壁的积极作用;旋流风量的增加对近壁处液滴的干燥速度及固体颗粒浓度的影响表明,旋流风量占总流量的16%左右合适。

EFFECT OF THE SWIRLING-STRAIGHT FLOW COMPOSITE FLUIDIZATION MODE ON WALL STICKING IN CFB-FGD TOWER

The gas-liquid-solid parameters relating to wall deposition of droplets or aqueous particle in CFB-FGD tower have been studied under the condition of swirling-straight flow composite fluidization mode by means of 3D-PDA. The results indicate that the gas-solid tangential velocity, relative tangential slippage velocity and disturbance are enhanced, and the solid particle concentration is also increased in the middle and lower part of tower, especially near to the wall of tower, which is beneficial to rapid dryness and reducing wall sticking of the droplets or aqueous particles. The helpful effect of the swirling-straight composite fluidization mode on reducing wall sticking of droplets and aqueous particle is also proved by the droplets distribution under this fluidization mode.According to the effect of swirling flow volume increase on droplets drying velocity and solid particle concentration, it is appropriate that swirling flow volume accounts for 16% of total volume.