移动床热煤气脱硫气固反应过程模拟——Ⅱ-错流移动床非催化气固反应过程模拟

IMULATION OFHOT GASDESULFURIZATION REACTION IN MOVING BED REACTOR——Ⅱ- SIMULATION OF HOT GASDESULFURIZATION REACTIONIN CROSS FLOW MOVING BED REACTOR

基于前文错流移动床反应器模型方程，模拟计算并分析了该类反应器中气、固相流动对热煤气脱硫等非催化气固反应过程的影响。研究表明，床层在床深方向按反应速率的快慢可分为粗脱区和精脱区，在颗粒流动方向上气相浓度差异较大，并主要体现在粗脱区内，床层出口处颗粒转化率呈现较大分布，反应器内气固交错流动、气相浓度和颗粒转化率共同作用（ 于气固反应速率） 等因素是造成过程特征的主要因素。因此反应器优化应满足对两相流动的优化，将粗脱区设置成错流移动床而精脱区设置成固定床，并使粗脱区内颗粒流速沿气流方向逐渐减小，以减小出口颗粒转化率的分布并提高颗粒利用率，同时沿颗粒流动方向应逐渐减小过床气流体积分率以利于床内气固反应速率的均一分布。由此指出对该类床型其底部渐缩下料段和过床气流对床内颗粒流动的影响以及床层结构及颗粒流动对过床气流分布的影响研究的必要性。

Based onthe developmentof modelequationsforthe non - catalytic gassol id reactionin crossflow moving bed reactorinthe previous paper,the simulation and analy sisofreactor behaviors were given-Itshowedthatgas and solid conversion distribution along both theirflow directions and gas and solid reactions has an effecton each other because of the crossflow configuration ofgas and solid andthe characteristicsofnon - catalyticgassol id reaction- Itis pointed outthatthe plug flow of gas and solid are notthe optimum flow types- The bed can be considered astwo parts alongthe bed depth (the gasflowing direc tion) in which differentsolid velocity distributionsshould be setto minimizethe distribution ofthe solid conversion- The gas flow across the bed should also be set as distribution of gradually decreasing along solid flow direction in orderto make the uniformity of gas solid reaction rate and preventthe gas - phase reactantfrom channeling or short- circuit- The sorbing capability of sorbent is also an important factor affecting on the bed behaviors- Thus,theinnovation and optimization ofreactorshould meetthe optimization ofthe gas and solid flow in bed- Among ofthem ,factorsincludingthe hopper below the bed and thefric tionalforce ofgas acting on particles,which affectthe solid flow in bed ,are mostimpor tant-