污泥水热氧化环流反应器的设计及优化

Optimization Design of Airlift Loop Reactor for Hydrothermal Oxidation of Sludge

环流反应器是非常适合于污泥水热氧化的一类气液反应装置。从实验研究和计算机模拟两个方面对环流反应器性能进行了初步探索,建立了处理量为0.1 m3/h的环流反应器冷模实验装置,并就反应器的喷嘴类型和数量、高径比(H/D)、下降区与上升区截面积之比(Ad/Ar)和颗粒沉积展开了若干实验;建立了计算流体力学(CFD)模型,并利用Design Expert软件对环流反应器进行了设计优化。实验结果表明,环形喷嘴(环隙进气)、H/D为10及Ad/Ar为0.333时,反应器性能较优。表观气速增大到0.0070 m/s时,大部分颗粒物悬浮,进一步增大表观气速,只有少量颗粒物沉积。CFD模型计算值与实际值偏差较小,误差在10%以内。优化后,上升区含气率提高了9%。

Airlift loop reactor is a kind of gas-liquid reaction apparatus,which is very suitable for sludge hydrothermal oxidation.The experimental research and computational simulation of airlift loop reactor were carried out in this article.A 0.1 m3/h cold model experimental apparatus was built and several experiments focusing on type and number of nozzles,height-to-diameter ratio(H/D),cross-sectional area ratio of the downcomer to the riser(Ad/Ar)and particles deposition were studied.By using computational fluid dynamics(CFD)simulation and software of Design Expert,the structure of reactor was optimized.The results indicated that the reactor with annular nozzle(annular intake),H/D ratio in 10 and Ad/Ar ratio in 0.333 had superior performance.Most of the particles were suspended when the superficial gas velocity reached 0.0070 m/s and fewer were deposited with higher superficial gas velocity.The error between calculated value of CFD and experimental value was less than 10%.After optimization by Design Expert software,the gas holdup in riser increased by 9%.