摘要
实现颗粒按密度为主导的分离是气流分选研究的关键.对于传统气流分选,运动颗粒的空气动力学特性,即颗粒的沉降末速是影响气流分选的主要因素.理论上在稳定的上升流中,无法实现颗粒按密度为主导的分离.阻尼式脉动气流分选机气流在局部产生加速效应,可以使颗粒按密度分离.通过阻尼式脉动气流分选机流场模拟实验,揭示了气流在阻尼块附近的流场特性,得出了气流在阻尼块上部区域存在明显加速效应的结论,为脉动气流分选效果优于传统气流分选提供了理论依据.实验室实际物料分选实验表明,阻尼式脉动气流分选装置比传统气流分选机有更优越的分选效果,总分选效率提高6%～8%.
It is an important task for the research of air classification to achieve denslty-domlnant separation. The performance of conventional air classifiers to separate particles is based on difference of their terminal velocities, which is caused by aerodynamic characteristics. Theoretically, in steadily rising air streams, the separation of particles based upon their density is not possible. Passive pulsing air classifiers have accelerated airflow in certain regions, which can obtain density-dominant separation. Simulation of airflow patterns within passive pulsing air classifiers was done. The airflow characteristics near a damper were indicated and the significant acceleration of the airflow above the damper was estimated. This provides a theoretic proof that passive pulsing air classifiers are superior to conventional air classifiers. The results of laboratory actual material separation have also shown the superiority of passive pulsing classifiers. The total separation efficiency is raised by 6%-8%.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2005年第5期574-578,共5页
Journal of China University of Mining & Technology
基金
国家杰出青年科学基金项目(50025411)
关键词
脉动气流
阻尼
流场模拟
加速效应
密度
pulsing airflow
passive
simulation of airflow patterns
acceleration effect
density
