打磨作业过程金属粉尘扩散特性及集尘罩除尘效果  

Metal dust diffusion characteristics and dust hood effect during grinding operation

作　　者：张国梁 蒋仲安[1] 陈记合 陈建武 杨斌[1,2] 赵东巍 ZHANG Guoliang;JIANG Zhongan;CHEN Jihe;CHEN Jianwu;YANG Bin;ZHAO Dongwei(School of Civil and Resource Engineering,University of Science and Technology Beijing;China Academy of Safety Science and Technology,Beijing100029,China;CRRC Changchun Railway Vehicles Co.Ltd.,Changchun 130062,China)

机构地区：[1]北京科技大学土木与资源工程学院,北京100083 [2]中国安全生产科学研究院,北京100029 [3]中车长春轨道客车股份有限公司,吉林长春130062

出　　处：《中南大学学报（自然科学版）》2021年第11期3813-3825,共13页Journal of Central South University:Science and Technology

基　　金：国家重点研发计划项目(2016YFC0801700);中国安全生产科学研究院基本科研业务费专项资金项目(2019JBKY04,2019JBKY11)。

摘　　要：为改善切削打磨场所粉尘质量浓度较高的问题,首先,以轨道列车厢体打磨车间为研究对象,对打磨过程产生的粉尘粒径分布、形貌特征和空间质量浓度进行测试;其次,采用SolidWorks和ANSYS建立打磨作业粉尘扩散模型;最后,对不同条件下的流场和颗粒运动轨迹进行模拟,分析角磨机集尘罩集尘效果。研究结果表明:粉尘在空间的扩散满足多元高斯分布,在打磨点附近粉尘质量浓度最高,两侧底角质量浓度较低;长时间作业空间粉尘平均质量浓度约为10 mg/m^(3),打磨点位置粉尘质量浓度最高达20.9 mg/m^(3),远高于规定值;颗粒粒径分布符合罗辛-拉姆勒分布,在0.1~656.0μm之间,特征指数为2.06,以条状、球状和块状颗粒为主;砂轮高速旋转时会在周围形成旋转诱导气流场,其近壁面速度与砂轮旋转线速度一致;在砂轮旋转诱导气流和切削初动能的作用下,不同粒径颗粒会以不同的角度向右前方扩散;粒径越小,受旋转气流场的影响越大,倾斜角度也越大;随着砂轮转速增加,粉尘扩散范围变大,方向性更加明显,粉尘聚集区由砂轮左侧顺时针偏移到砂轮右前方;安装集尘罩后,除打磨点位置,空间整体粉尘质量浓度下降了2~3个数量级;吸入集尘罩的粉尘质量流率能达到2~4 mg/s,占总产尘量的36%~57%;吸入的颗粒粒径以0~200μm为主,占95%以上。随着集尘罩风量增加,粉尘质量流率会进一步上升,同时吸入颗粒中大颗粒比例也增加。To solve the problem of high dust mass concentration in the cutting and grinding workplace, firstly, the grinding workplace of railcar body was taken as the research object, and the particle size distribution,morphological characteristics and spatial mass concentration of dust generated from the grinding process were measured. Secondly, SolidWorks and ANSYS were used to establish dust diffusion model of grinding operation.Thirdly, the flow fields and particle trajectories were simulated under different conditions and the dust collection effect of the dust hood was analyzed. The results show that the dust diffusion in space satisfies the multivariate Gaussian distribution, the highest mass concentration of dust is near the grinding point and the lowest mass concentration is at the bottom corners on both sides. The average mass concentration of the long-term working is about 10 mg/m^(3), and the mass concentration at the grinding point is up to 20.9 mg/m^(3), which is much higher than the specified value. The particle size distribution conforms to the Rosin-Rammler distribution, between 0.1-656.0μm, with the characteristic index of 2.06. The particle shapes are mainly strips, spheres and blocks. When the grinding wheel rotates at high speed, a rotationally induced airflow field forms around it. The velocity of the airflow near the wall of grinding wheel is the same as the linear velocity of grinding wheel. The different particle sizes spread at different angles to the right front under the action of rotation-induced airflow and initial kinetic energy. The smaller the particle size, the greater the influence of the rotation-induced airflow and the greater the tilt angle. As the rotation speed of the grinding wheel increases, the dust diffusion range becomes larger, and the directionality becomes more obvious. The dust gathering area rotates clockwise from the left side of grinding wheel to the right front of grinding wheel. After installing the dust hood, the overall dust mass concentration in the space drops by 2-

关 键 词：打磨 粉尘控制 粒径分布 砂轮转速 集尘罩 质量流率 

分 类 号：X964[环境科学与工程—安全科学]