LIU Dandan¹, ZHU Hongfei¹, LI Dewen², GUO Shengjun², WANG Chunmei²

(1. School of Electrical and Control Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China;2. China Coal Technology Engineering Group Chongqing Research Institute, Chongqing 400037, China)

Abstract

Objective The particle size of rock dust is much smaller than that of coal dust, allowing it more inhalable and thus more harmful to the lungs. To solve the classification problem of mixed particles containing both coal dust and rock dust, a micrometer measurement method for such mixed particles is proposed.

Methods Firstly, a model for a ring electrostatic sensor was established. Subsequently, according to the measurement principle of resonant U-type coriolis mass flow meter, it was proved that the mass flow of fluid could be calculated by measuring the time difference between the two sides of the tube. Secondly, considering the structure parameters of the resonant U-shaped pipe, the modal analysis of the resonant U-shaped measuring pipe was carried out by ANSYS Model software. The analysis determined that the excitation frequency of coriolis mass flow meter. Thirdly, the measuring process of coriolis mass flow meter was simulated using the two-way fluid-solid coupling approach. The theoretical feasibility of classifying mixed particles was verified by this simulation, coupled with the coriolis mass flow meter device. Finally, the relationship between particle density and mechanical properties of coal dust and rock dust was analyzed. With the change of coal dust volume fraction, the static parameters and time difference of coal dust and rock dust mixed particles with different particle sizes were studied. The mixed particles of coal dust and rock dust with the same particle size were studied with the change of coal dust volume fraction and particle velocity.

Results and Discussion In the same measuring pipe inlet of coriolis mass flow meter, the inflow velocity of particles is positively correlated with the measurement time difference. Modal analysis reveal that the excitation frequency of coriolis mass flow meter should be the natural frequency 113. 11 Hz, corresponding to the second order mode of the resonant U-type measuring tube. When coal dust and rock dust particles with different particle sizes are mixed, it is observed that the maximum static pressure, the total maximum shape variable, the maximum equivalent stress and the time difference decrease with the volume fraction of coal dust particles increases. The time difference of total rock dust and total coal dust differs from that of mixed particles. Specifically, when coal dust and rock dust particles of the same particle size are mixed, the time difference decreases sharply with the increase of coal dust volume fraction. The time difference increases with the increase of the volume flow rate of mixed particles. When the coal dust volume fraction is less than 50%, the larger the particle size, the larger the time difference. When the coal dust volume fraction is greater than or equal to 50%, the larger the particle size, the smaller the time difference.

Conclusion Coal dust particles and rock dust particles have distinct and different classification and discrimination characteristics. The feasibility of micrometer classification of mixed particles including coal dust and rock dust is verified. The coriolis mass flow meter demonstrates the capability to accurately classify the mixed particles of coal dust and rock dust in real time.

Keywords: coal dust particle; rock dust particle; Coriolis mass flow meter; electrostatic sensor; finite element software; two-way fluid-solid coupling

Get Citation:LIU D D, ZHU H F, LI D W, et al. Classification of micron coal dust and rock dust particles based on Coriolis mass flow meter[J]. China Powder Science and Technology, 2024, 30 (1): 132-143.

Received: 2023-08-07,Revised:2023-11-22,Online:2023-12-13。

Funding Project:国家重点研发计划项目,编号:2017YFC0805208。

First Author:刘丹丹(1978—),女,教授,博士,硕士生导师,研究方向为矿山安全监测与电气设备控制。 E-mail: liudandan2003@163.com。

Corresponding Author:朱鸿飞(1998—),男,硕士生,研究方向为电气设备状态监测与矿山安全监控。 E-mail: 1216358329@qq.com。

CLC No: X936; TB4         Type Code :A