摘要
传统水力分级机给料方式通常为垂直给料,容易造成分级腔内流场紊乱,特别是高速给料时流场恶化尤为严重,导致分级精度低、分级效率低等问题。为此,提出一种切向进料、带有W型反射盘的新型水力分级机。采用计算流体动力学软件对新型水力分级机内部流场进行了数值模拟分析。结果表明:新型分级机通过设置切向进料管结构,物料以螺旋下降方式进入分选腔,下降速度降低,物料分散更充分;通过在给料口设置W型反射盘后能够产生向上折返流,减缓了物料与上升水流的对冲,内部流场分布更均匀;适当增加给料速度后,对新型分级机分级腔内湍动能影响不大,有利于物料分级,提高分级精度。对粒径小于0.075mm的铁粉进行分级对比试验表明:新型分级机分级效率是传统型分级机的1.25倍,溢流产率是传统型分级机的1.46倍。相比于传统分级机,新型分级机在分级效率和产率2方面都得到了有效改善和提高。
The vertical feed inlet of the traditional hydraulic classifier often causes disordered flow field in the classify ing chamber,leading to low classification accuracy,small capacity and low efficiency. It is especially deteriorated for feed with high inlet velocity. A new type of hydraulic classifier characterized by tangential feed inlet and W-type reflective disk was proposed. The internal flow field was simulated using the computational fluid dynamics software. The results show that the new classifier is equipped with a structure of tangential feed tube,and the material enters the separation chamber in the way of spi ral,the falling speed decreases,and the material disperses more fully. By setting a W-type reflective disk at the feed inlet, the upward folding flow can be generated,which reduces the collision between the material and the rising water flow,and the internal flow field distribution will be more uniform. When the feeding speed is increased properly,the effect on the turbulent kinetic energy is small in the separation chamber of the new classifier,which is beneficial to the material classification and improves the classification accuracy. The classification experiment on iron powder with particle size less than 0.075 mm shows that the classification efficiency of the new classifier is 1.25 times of the traditional classifier,and the overflow yield is 1.46 times of the traditional classifier. Compared with the traditional classifier,the new classifier has been effectively improved and increased in terms of classification efficiency and yield.
作者
张悦刊
曹井振
刘培坤
杨猛
郑雪飞
Zhang Yuekan;Cao Jingzhen;Liu Peikun;Yang Meng;Zheng Xuefei(College of Mechanical & Electronic Engineering,Shandong University of Science and Technology,Qingdao 266590,China)
出处
《金属矿山》
CAS
北大核心
2019年第6期168-172,共5页
Metal Mine
基金
山东省自然科学基金项目(编号:ZR2016EEM37)
山东省重点研发计划项目(编号:2017GSF216004)
关键词
带有W型反射盘的新型分级机
内部流场
分级效率
数值模拟
New classifier characterized by W-type reflective disk
Internal flow field
Classification efficiency
Numeri cal simulation