摘要
运用计算流体力学方法对DTB流化床结晶器内循环流量对流体悬浮状态的影响以及不同粒径颗粒在出口处固体质量流率的变化情况进行模拟。模拟结果表明,保持进料流量一定的情况下,外循环流量与进料流量的比值也对结晶器内流体的体积分数分布情况有着显著的影响,然而,循环流量的加大也会增加结晶器内颗粒的碰撞与破碎的几率,不利于晶体的成核与成长。另外一组模拟结果还表明,不同粒径的颗粒在各出口处的质量流率差异明显,本模拟条件下,粒径为0.5 mm以下固相颗粒基本上由循环出口排出,而粒径0.5 mm及以上的固相颗粒则能够在导流筒与挡板之间循环流动,这意味着在一定条件下,能够控制一定粒径的颗粒在结晶器内的悬浮流动,这对于控制一定粒径范围的晶体的成核与成长有着重要的作用。
The influence of circulation volume on the solid suspension status as well as the mass flow at different outlet of varied particle size was simulated in a fluidized DTB crystallizer by using the method of computational fluid dynamics（CFD）.Simulation results indicated that when the inlet volume was constant,the ratio of the circulation volume and the inlet feeding volume has an significant impact on the distribution of liquid volume fraction.However,as the circulation volume increased,the possibility of collision and breakage among particles increased,which is negative for the generation and growth of crystal.Another simulation also showed that the mass flow of different particle sizes had evident difference at different outlets.In the current simulations,solid particle size smaller than 0.5mm is mainly discharged at the circulation outlets,while solid particle size equal or larger than 0.5mm is circulated between the draft tube and baffles.This result indicated that under specific condition,the suspension status of specific particle size can be controlled,which has an significant impact on the control of the generation and growth of crystals under certain size range.
出处
《盐业与化工》
CAS
2011年第4期29-33,共5页
Jounral of Salt and Chemical Industry
关键词
操作条件
DTB流化床结晶器
计算流体力学
悬浮状态
质量流率
operating condition
fluidized DTB Crystallizer
computational fluid dynamics（CFD）
suspension status
mass flow
