基于虚拟冲击原理的呼吸性粉尘连续分离技术  

Continuous separation of respirable dust based on virtual impactor principle

作　　者：惠立锋 李德文[2,3] 郭永彩[1] HUI Lifeng;LI Dewen;GUO Yongcai(Key Laboratory of Optoelectronic Technology&System,Ministry of Education,Chongqing University,Chongqing 400044,China;State Key Laboratory of the Gas Disaster Detecting Preventing and Emergency Controlling,Chongqing 400037,China;China Coal Technology Engineering Group Chongqing Research Institute,Chongqing 400037,China)

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044 [2]瓦斯灾害监控与应急技术国家重点实验室,重庆400037 [3]中煤科工集团重庆研究院有限公司,重庆400037

出　　处：《中南大学学报（自然科学版）》2022年第8期3062-3070,共9页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2017YFC0805200);重庆市自然科学基金项目(cstc2020jcyj-msxm X0512)。

摘　　要：呼吸性粉尘连续分离技术是实现其在线监测和尘肺病预警的基础及关键。为了解决常见的旋风分离、水平陶析及平板冲击等分离方式易积尘、过载、堵塞等弊端,提出一种基于虚拟冲击原理的呼吸性粉尘连续分离技术。基于虚拟冲击理论,建立呼吸性粉尘虚拟分离三维模型,仿真分析其速度场和压力场的分布,通过分域法阐释虚拟冲击的分离机理,并构建分离效能和分离时效一体化测试系统,对设计的虚拟冲击器进行验证。研究结果表明:分离效能模拟曲线随着喷嘴与收集腔间距和收集腔直径增大而上移,而收集腔直径对分离效能的影响作用强于喷嘴与收集腔间距的影响。当喷嘴与收集腔间距为4.0 mm、收集腔直径为3.0 mm时,各个粒径点的分离效率与BMRC曲线的偏差在±5%以内。在工作点流量为4 L/min、弱流比为0.1条件下,分离器的分离效能曲线与BMRC曲线相比,整体呈负偏差,最大偏差为-4.7%。在质量浓度为35~40 mg/m~3的粉尘浓度环境下,传统旋风分离器容易出现排灰口和排气口堵塞,测试结果偏差较大,连续运行1 d后已不能满足连续分离要求,而虚拟冲击式分离器内部颗粒损失及截留较少,可实现15 d以上的连续运行而无需人工清理,连续分离时效提升了10倍以上,验证了本文方法的可行性及优越性,满足呼吸性粉尘浓度在线测量对粉尘连续分离的分离效能及分离时效要求。The continuous separation technology of respirable dust is the basis and key of its online monitoring and early warning of pneumoconiosis. In order to overcome the disadvantages of separation methods such as cyclone, horizontal elutriator and plate impactor, where dust on accumulation dust, overload, and blockage are easy to happen, a continuous separation technology of respirable dust based on virtual impact principle was proposed. Based on the virtual impact theory, a three-dimensional model of the respirable dust virtual separator was established, and the distribution of the velocity field and pressure field was simulated and analyzed, and the separation mechanism of the virtual impactor was explained through the method of area division. Then, an integrated test system for separation efficiency and separation timeliness was built to verify the virtual impactor designed. The results show that the separation efficiency curve increases with the increase of the hole spacing and the diameter of the collecting cavity, and the effect of the collecting cavity diameter on the separation efficiency is stronger than that of the hole spacing. When the hole spacing is 4.0 mm and the collecting cavity diameter is 3.0 mm, the deviation value between the separation efficiency of each particle size point and the BMRC curve is within ±5%, which provides a basis for the design of the virtual impact separator. At the flow rate of 4 L/min and weak flow ratio of 0.1, the separation efficiency curve of the separator is negative on the whole, with the maximum error value of-4.7% compared with the BMRC curve. In the dust concentration environment of mass concentration of 35~40 mg/m~3, the cyclone separator is prone to clogging of the ash discharge port and exhaust port, and the test results have large deviations. After 1 d of continuous operation, it is no longer able to meet the continuous separation requirements. However, the virtual impactor has less internal particle loss and retention,and can achieve continuous operation for mor

关 键 词：呼吸性粉尘 连续分离 分离效能 BMRC曲线 虚拟冲击 

分 类 号：TD714[矿业工程—矿井通风与安全]