关键词: 气力输送, 实验测量, 计算流体力学和离散单元耦合, 输送流型, 压力损失

Abstract: Pneumatic conveying has the characteristics of environmentally friendly, operational safety, spatial intensification, flexible configuration, and easy to automate. In addition, this bulk material handling method also has the advantages of quantitative conveying, conveniently dispersing or centralized conveying, and inert gas protection conveying for unstable materials. The aforementioned characteristics pneumatic conveying to a commonly clean conveying technology for bulk materials. At the same time, pneumatic conveying has been widely applied in chemical, food, pharmaceutical, energy industries, and other fields. However, this method also has a few problems, such as high energy consumption, particle degradation, and pipe erosion. The fundamental cause of the disadvantages lies in the complex conveying process, transient state of particle conveying, and difficulty in accurate prediction. Therefore, the multi-means characterization and prediction of material conveying characteristics in different conveying processes have always been the hot points of this technology. It is well known that the equipment composition is the foundation of pneumatic conveying system performance. In addition, the feeding device is one of the most important factors for conveying processes. In this meaning, this work first summarized the structure of the pneumatic conveying system and the structural characteristics of commonly used feeding devices. Then, this work reviews the application and research of the numerical simulation methods including the two-fluid model in the computational fluid dynamics and the coupling simulation of the computational fluid dynamic discrete element method (CFD-DEM). The application conditions, merits, and demerits of the common numerical method are discussed. What is more, the research and application status of measuring devices commonly used in pneumatic conveying are summarized, including electrical capacitance tomography (ECT), pressure determination, and acoustic emission. Meanwhile, the study mainly focuses on flow pattern evolution and pressure loss in the conveying system, as well as some interesting study points of pneumatic conveying, which are well explored. Finally, several thinking points for future research on this technology are discussed.

Key words: pneumatic conveying, experimental measurement, CFD-DEM, flow regime, pressure drop