Elaborate Classification of Fine Particles by Modified Type Cyclone and Its Optimization

改进型旋流器细颗粒分级及其优化

基本信息

批准号：
09650831
负责人：
YOSHIDA Hideto
金额：
$ 2.18万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650831/
关键词：
cyclone classification fine particles simulation collection optimization separation efficiency 環境分補効率

项目摘要

Experimental studies were conducted on the classification of fine particles by use of a modified cyclone with movable 50% cut size on a bench scale. The 50% cut size of cyclone changed from 1 to 10 , u m by the change of apex cone height and blow-up flow rate. When the height of apex cone was higher at a constant blow-up flow rate, the 50% cut size increased. The reason for this was due to the fact that a decrease in the effective cross-sectional area near the inlet of the dust box gave rise to the increased average upward fluid velocity.In the case of blow-down, two kinds of different-sized fine particle were obtained simultaneously. When the blow-down flow rate was 5%, collection efficiencies of 4 and 28% were obtained with mean particle diameters 2 and 6 mu m respectively. When both the blow-down method and a movable guide plate at the cyclone inlet were used, particles of average diameter of 1.5 mu m were collected. Although the cyclone diameter was 400 mm, elaborate classification of fine particles was achievable.In order to obtain the information of the high-performance cyclone classifier, three-dimensional numerical simulation and experimental studies were conducted on the fluid flow and particle trajectory in a cyclone classifier with and without blow-down. By use of blow-down method, the overall separation efficiency of a cyclone is higher than the case without blow-down. From the results of simulation, the reason for this is found to be the fact that downward velocity components near the conical wall are stronger in the case of blow-down compared to the case without blow-down.

通过使用具有可移动 50% 切割尺寸的改进型旋风分离器，在实验室规模上进行了细颗粒分级的实验研究。通过改变顶锥高度和吹扫流量，使旋流器的50%截断尺寸从1μm变为10μm。在恒定吹胀流量下，当顶锥高度较高时，50%切割尺寸增加。其原因是由于集尘箱入口附近的有效截面积减小，导致平均向上流体速度增加。在排污情况下，两种不同尺寸的同时得到细颗粒。当排污流量为5%时，平均粒径为2μm和6μm时，收集效率分别为4%和28%。当同时使用吹扫法和旋风分离器入口处的可移动导流板时，收集到的颗粒平均直径为1.5μm。尽管旋流器直径为400 mm，但仍可实现细颗粒的精细分级。为了获得高性能旋流器分级机的信息，对旋流器内的流体流动和颗粒轨迹进行了三维数值模拟和实验研究带或不带排污的分级机。采用排污方式，旋风分离器的整体分离效率比不排污的情况要高。从模拟结果来看，造成这种情况的原因是，与没有排污的情况相比，在排污的情况下，靠近锥壁的向下速度分量更强。