文献类型：期刊文献

英文题名：Characteristics and formation mechanism of plug flow in the industrial vertical pipeline of dense-phase pneumatic conveying of pulverized coal

作者：Jin, Yong[1];Lu, Haifeng[1];Guo, Xiaolei[1];Gong, Xin[1]

机构：[1]East China Univ Sci & Technol, Shanghai Engn Res Ctr Coal Gasificat, Key Lab Coal Gasificat & Energy Chem Engn, Minist Educ, Shanghai 200237, Peoples R China

年份：2019

卷号：205

起止页码：319

外文期刊名：CHEMICAL ENGINEERING SCIENCE

收录：;EI(收录号：20192006923562);WOS:【SCI-EXPANDED(收录号:WOS:000470303000030)】；

基金：This work was supported by the National Key R&D Program of China (2018YFC0808503), the National Natural Science Foundation of China (51876066), the Shanghai Engineering Research Center of Coal Gasification (18DZ2283900) and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Dense-phase pneumatic conveying; Plug flow; Particle velocity; ECT; Jansen stress analysis

摘要：Plug flow, which affects the reliable feeding of pulverized coal, is one of flow patterns in dense-phase pneumatic conveying of pulverized coal. The control and formation mechanism of plug flow are very important for the industrial application and theoretical research. In this work, experiments were carried out on a pneumatic conveying test platform in the Key Lab of Coal Gasification and Energy Chemical Engineering of Ministry of Education, ECUST, to study on the plug flow in the industrial vertical pipe under a low superficial gas velocity. All the flow states and flow patterns of the dense-phase pneumatic conveying process were analyzed. The present study shows that five different particle velocity distributions were found in the plug flow. However, the time series of the pressure and solid concentration signal are almost the same. What's more, the power spectral density function analysis provides the relationship of the solid concentration signal of the cross-section by the electrical capacitance tomography (ECT) between all four operational cases and five different kinds of plug flows. From the point view of application, five different kinds of the plug flow were characterized by the plug length, fluctuation parameter of the plug flow (the Strouhal number) and the operational parameters (Lockhart-Martinelli parameter and the Froude number of the gas phase and the solid phase). Based on the phase diagram constructed using the Strouhal number and Lockhart-Martinelli parameter, five types of plug flow could be predicted. A larger Strouhal number indicates the poorer stability of the plug flow. Moreover, the formation mechanism of the plug flow was analyzed by the Janssen equation. Finally, we found that all types of the plug flow have the same unit friction force based on a statistical discussion. Through this work, we wish that our research will give a deeper understanding of the formation and control of the plug flow in the dense-phase pneumatic conveying of pulverized coal. (C) 2019 Elsevier Ltd. All rights reserved.