提升管反应器进料混合段内气固两相流动特性(Ⅱ)理论分析

针对提升管进料混合段这一复杂的混合流场建立了轴向颗粒返混模型 ,用以计算颗粒相返混比、轴向速度以及混合相密度等 ,从而将颗粒相的流动描述成单一参数控制的行为 .并根据多相流动的扩散模型和冷态实验的结果给出了射流相浓度在截面上分布规律的计算方法 ,指出该浓度分布主要与射流气速和预提升表观线速的速度比有关 ,而其他操作参数的影响都是次要的 .

GAS- SOLID TWO PHASE FLOW IN FEED INJECTION ZONE OF FCC RISER REACTORS (Ⅱ) ANALYTICAL RESEARCH

Fluid catalytic cracking (FCC) process is one of the most important heavy oil upgrading techniques in the petroleum refining industry,and riser reactor is the crucial part in FCC unit. An axial Particle Backmixing Model is established.By using two experimentally regressed parameters and the axial Particle Backmixing Model,the flow parameters of the particle phase such as mean density,mean axial velocity can be predicted well. The method for calculating radial distribution of nozzle jet in different riser cross-section is obtained,which considers both the Two Phases Diffusion Model and experimented results.It is also found that the ratio of pre-lift gas velocity and nozzle jet velocity is the decisive factor in this distribution while other operation parameters are secondary relatively.