循环流化床旋直复合流化下的两相流动试验研究

Experimental Study of Two-phase Flows in a Circulating Fluidized Bed under a Rotating and Straight Compound Fluidization

通过提高塔内混合和物料浓度是提高循环流化床烟气脱硫效率的途径。提出了旋直复合流化方式,并用PDA测量系统对塔内气固两相流场进行测试,得到了文丘里喉管安装轴向旋转叶片前后脱硫塔体内气固流动规律。结果表明,非均匀布风的旋直复合流化方式提高塔内切向速度,塔内的脉动强,混合好,增加了塔内颗粒浓度和内循环,而且表观速度越高的复合流化的综合效果更好。试验结果为烟气脱硫新工艺的结构设计及优化提供了依据。

To increase in-tower blending and material concentration represents an approach for raising the flue gas desulfuration efficiency of a circulating fluidized bed.The authors have proposed a rotating and straight compound fluidization mode and measured gas-solid two-phase in-tower flow field by using a PDA (Phase Doppler Anemometer) measurement system.Obtained was a law governing the gas-solid two-phase flows in a desulfuration tower before and after axial rotating blades were installed in a Venturi throat.It has been found that the non-uniform air distribution as characterized by the rotating and straight compound fluidization mode can help increase the tangential speed in the tower,leading to an in-tower strong pulsation,good mixing and resulting in a higher in-tower particulate concentration and an increased inner circulation.In addition,a higher superficial speed can bring about a better comprehensive effectiveness of the compound fluidization.The experimental results can provide an underlying basis for the structural design and optimization of new technologies for flue gas desulfuration.