移动床热煤气脱硫气固反应过程模拟Ⅲ错流及逆、并流移动床反应器的比较

SIMULATION OF HOT GAS DESULFURIZATION REACTION IN MOVING BED REACTOR Ⅲ BEHAVIOR COMPARISON OF CROSS FLOW, CONCURRENT FLOW AND COUNTERCURRENT FLOW MOVING BEDS

基于前文对错流移动床反应器的分析,进一步建立了逆、并流移动床非催化气固反应器模型方程,对不同操作条件下错流和逆、并流三类移动床反应器的行为进行了比较。结果表明,三类不同气固接触方式移动床的行为存在差异,其根本原因在于其内进行的非催化气固反应过程受固剂转化率的影响,当反应属本征动力学或内扩散控制时,错流、逆流移动床的床层利用效率较高,但反应属外扩散控制如在加压条件下操作或所要求的固剂转化率可降低时,三类移动床反应器床层利用效率趋于一致。

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-