底隙高度对生物流化床内流场和氧传质特性的影响

EFFECT OF GAP HEIGHT OF BASE SLOT ON LIQUID FLOW FIELD AND OXYGEN MASS TRANSFER IN A BIOLOGICAL FLUIDIZED BED

针对生物流化床内构件中底隙高度的设计、优化问题,应用激光粒子图像测速(PIV)和溶解氧在线测试技术,分析了不同曝气强度和底隙高度对生物流化床液相速度、湍动能和氧传质特性的影响。结果表明:底隙高度为75 mm时生物流化床的底部液速和整体液速最大,整体液相湍动能较小。同时,在氧转移系数和转移效率上,有较小的劣势。从结构优化的角度出发,当折流板底隙高度为75 mm时整体效果最好,有利于节约能耗和降低成本。以期为更全面、深入地分析生物流化床其他内构件的协同作用及寻找最佳液相流场和氧传质特性提供参考。

Aiming at the design and optimization problem of gap height of base slot in the internal components of the biofluidized bed,the effects of different aeration intensities and different gap heights on liquid phase velocity,turbulent kinetic energy and oxygen mass transfer characteristics of biofluidized beds were analyzed by applying laser particle image velocity(PIV)and dissolved oxygen online testing techniques.The result showed that the bottom liquid velocity and the overall liquid velocity of the fluidized bed were maximum when the gap height was 75 mm,and the overall liquid phase turbulent kinetic energy was relatively smaller.Morever,there were small disadvantages in oxygen mass transfer coefficient and mass transfer efficiency.From the perspective of structural optimization,the overall effect was the best when the baffle had a low clearance height of 75 mm,which was conducive to saving energy consumption and reducing cost.In addition,the optimal liquid phase flow field and oxygen mass transfer characteristics,and a more comprehensive and in-depth analysis of the synergy of other internal components of the biological fluidized bed were still required.