Fundamental Research on an Innovative Fluid-Bed Type Reactor For Fluidization of Ultra-Fine Particles

一种用于超细颗粒流态化的创新型流化床反应器的基础研究

基本信息

批准号：
11305056
负责人：
KATO Kunio
金额：
$ 17.3万
依托单位：
Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

项目摘要

Cold model experiments were carried out for the development of an innovative fluid-bed type reactor for fluidization of ultra-fine particles. Coarse particles with mean size about 70 μm (FCC particles in Geldart group A) were fluidized with superficial gas velocities 0.5〜1.0 m/s, while fine powders with mean size 0.5 to 15.0 μm (several kinds in Geldart group C) were fed continuously into the dense phase. Investigations were carried out under various operating conditions on the dependent relationship of solid entrainment rate, separation rate of fine particles, and steady state region to fine particles hold-up (weight of fine particles per unit weight of bed particles).When fine particles hold-up was high, fluidization phenomena changed due to formation of particulate aggregate complex for the cases of fine particle sizes less than several μm. Solid entrainment rate increased with decreasing fine particles hold-up, and increasing superficial gas velocity and size of fine particles. Separation rate of fine particles increased with increasing fine particles hold-up, superficial gas velocity and size of fine particles.Tests of continuous feeding of fine particles demonstrated that the operational range was separated into two distinctive ones. One was the region where steady state was maintained, and another was the region where accumulation of fine particles occurred. Steady state operation was impossible when the ratio of discharge rate to feed rate of fine particles fell below unity due to fatal agglomeration in the bed. Steady state operation was also impossible when the size of fine particles was larger than a certain value due to collection of fine particles by cyclone. Hold-up of fine particles in the steady state increased with decreasing superficial gas velocity and size of fine particles and increasing feeding rate of fine particles.

为了开发一种用于超细颗粒流化的创新型流化床反应器，进行了冷模型实验，以0.5～1.0的空塔气体速度流化平均尺寸约为70μm的粗颗粒（Geldart A组中的FCC颗粒）。 m/s，同时将平均尺寸为 0.5 至 15.0 μm 的细粉末（Geldart C 组中的几种）连续送入致密相中进行研究。在各种操作条件下，固体夹带率、细颗粒分离率和稳态区域与细颗粒滞留量（每单位重量床颗粒的细颗粒重量）之间的依赖关系。当细颗粒滞留量较高时，对于细颗粒尺寸小于几微米的情况，由于形成颗粒聚集体复合物，流化现象发生变化。随着细颗粒滞留量的降低以及细颗粒分离率的增加，固体夹带率增加。颗粒随着细颗粒的增加而增加细颗粒的连续进料试验表明，操作范围分为两个不同的区域，一个是稳定状态区域，另一个是累积区域。当细颗粒的排出速率与进料速率之比低于1时，由于床中的致命团聚，稳态操作也无法进行。由于细小颗粒的收集稳定状态下细颗粒的滞留量随着表观气速和细颗粒尺寸的减小以及细颗粒进料速率的增加而增加。