循环流化床回流物料循环的特性  

Circulating characteristics of return particles in circulating fluidized bed

作　　者：张立强[1] 马春元[1] 宋占龙[1] 马鸿良[1] 潘光[2] 张淼[2] 

机构地区：[1]山东大学能源与动力工程学院,山东济南250061 [2]山东省环境监测中心站,山东济南250013

出　　处：《化学工程》2008年第6期22-25,共4页Chemical Engineering(China)

摘　　要：为了研究循环物料在流化床内回流并参与循环的过程,进一步揭示流化床内物料的循环特性,文中搭建了冷态循环流化床顶部回流试验台。利用激光多普勒粒子动态分析仪(PDA)对塔内颗粒回流时床内气固二相流场和颗粒浓度分布进行了测量。同时对物料回流量和床内表观气速等操作条件对回流过程的影响进行了考察。研究表明,回流颗粒在流化床内的返混可以分为3个区域:回流区、返混加速区和主流区,回流颗粒造成床内流场的不均匀性。回流长度主要受物料回流量和床内表观气速影响。In order to investigate the process of circulating particles returning to the main flow and to make the further discovery about the circulating characteristics of the particles in circulating fluidized bed （CFB）. The cold model experimental system of the particle flowing from the top of the CFB was set up. The gas-particle two-phase flow and the mass concentration of particles in the tower were measured by using the phase-Doppler particle dynamic analyzer （PDA） system. The effects of the operating parameters including the mass flow rate and the superficial gas velocity on the process of the particles returning to the main flow were investigated. The results indicate that the process of the particles returning to main flow can be divided to three parts ： the return field, the mixing and accelerating field and the main flow field. The return particles make the flow field become nonhomogeneous. The main factors which influence the back flow length are the mass flow rate and the superficial gas velocity.

关 键 词：循环流化床 顶部回流 循环特性 

分 类 号：TK229.6[动力工程及工程热物理—动力机械及工程]