Experimental study on the angle of repose of pulverized coal--颗粒学报PARTICUOLOGY

Wang, W., Zhang, J., Yang, S., Zhang, H., Yang, H., & Yue, G. (2010). Experimental study on the angle of repose of pulverized coal. Particuology, 8(5), 482-485. https://doi.org/10.1016/j.partic.2010.07.008

Experimental study on the angle of repose of pulverized coal

Wei Wang, Jiansheng Zhang^*, Shi Yang, Hai Zhang, Hairui Yang, Guangxi Yue

Department of Thermal Engineering, Tsinghua University, Beijing, 100084, PR China

10.1016/j.partic.2010.07.008

Volume 8, Issue 5, October 2010, Pages 482-485

Received 5 January 2010, Revised 24 February 2010, Accepted 1 July 2010, Available online 2 October 2010.

E-mail: zhang-jsh@tsinghua.edu.cn

Highlights

Abstract

An experimental study on the angle of repose (AoR) of pulverized coal with different particle sizes and different moisture contents (MC) was conducted. Three different measurement methods, free-base piling, fixed-base piling and sliding, were used. The data were analyzed by one-way and two-way analysis of variance. The results showed that the AoRs of pulverized coal with particle sizes smaller than 150 μm were in the range of 30–50°. The characterization of the flowability of pulverized coal was some cohesiveness or true cohesiveness. The increase of MC will increase AoR and thus decrease the flowability of the powder. However, the particle size effect is bifurcated. Below a critical size, the decrease of particle size decreases the flowability; while above the critical size, the decrease of particle size increases the flowability. It was found that the value of the critical size strongly depends on the powder density. Moreover, the AoR dependence on particle size could be linked with the Geldart's particle classification. The critical size at the turning point is on the boundary between Group A and Group B in Geldart's classification diagram. Based on the experimental results, there is no significant cross interaction between particle size and MC. The AoRs measured by free-base method and fixed-base method are close, but both remarkably smaller than that measured by the sliding method.

Graphical abstract

Keywords

Angle of repose (AoR); Pulverized coal; Particle size; Moisture content

文章导读