摘要
为解决变径水介质分选床中颗粒堆积及细粒级废弃电路板的有效物理分选,在现有的变径水介质分选床下壁面添加了多组顶流管,引入上升水流,加强了壁面堆积物料的松散与分选效果。详细分析了倾斜床体液固两相流的流型变化与特征,并采用ANSYS FLOTRAN CFD软件进行数值模拟,得到了介质流场的压强分布变化规律:流场压强自床体底端至顶端递减,自顶流孔给入的水流可以在床体顶流孔附近形成局部强压区,使分布在床体下壁面的颗粒产生额外的运动加速度。选用≤0.125、>0.125~0.250、>0.250~0.500mm废弃电路板颗粒进行两因素三水平分选实验,结果表明,采用顶流式变径液固流化床分选系统可实现≤0.500mm废弃电路板中金属成分的有效富集,金属回收率最大达到了93.23%。
To solve the problem of the particle accumulation on the variable diameter water medium separation bed （VDWMSB） and obtain effective physical separation of fine grained waste printed circuit boards,multi-group top flow tubes were added under the bottom wall of the existing VDWMSB to introduce upward flow. The loose degree and separation efficiency of the wall accumulation materials were enhanced. In this paper,the changes between liquidsolid two phase flow pattern of tilt table and their characteristics were analyzed and the ANSYS FLOTRAN CFD software for numerical simulation was used to obtain pressure distribution rule of the medium flow field：the flow field pressure decreased from the bottom to the top of the bed body; partial pressure zone was formed because of the flow from the top flow hole; the additional force was applied to the particles under the bottom wall of the bed body. Three groups of waste printed circuit boards particles which size fractions were ≤0.125,〉0.125-0.250, 〉0.250-0.500 mm were chosen to carry out two factors and three levels separation test. By using the new top streaming and varied diameter liquid-solid fluidized bed separation system,the results showed that the fine waste printed circuit boards particles which size fraction was 40.500 m m could be effectively separated,and metal recovery rate reached 93.23 %.
出处
《环境污染与防治》
CAS
CSCD
北大核心
2017年第1期45-49,共5页
Environmental Pollution & Control
基金
国家自然科学基金资助项目(No.91434133)
江苏省自然科学基金资助项目(No.BK2012136)
上海电子废弃物资源化产学研合作开发中心开放
开发基金资助项目(No.B50ZS120003)
关键词
废弃电路板
顶流式
变径液固流化床
流场分布
分选
waste printed circuit boards
top streaming
varied diameter liquid-solid fluidized bed
flow field distribution
separation
