Study on mass at the bottom of the pipe and gas velocity distribution during flow blockage collapsing under pipe‐rotation mechanism

Abstract

AbstractThe flow blockage of the horizontal pipe is a severe problem in dense pneumatic conveying; accelerating the collapse of blockage can improve the efficiency of powder transportation. In this paper, the pipe‐rotation mechanism was proposed for the first time, and its effect on blockage collapse was preliminarily discussed. A horizontal pipe‐rotation geometry with a linear variation of rotating speed was established, and the rotational speed was 0, 150, 300, 450, and 600 rpm, respectively. The collapsing process of a single slug passing through the rotating horizontal pipe was simulated by using the Computational fluid dynamics (CFD)‐discrete element method (DEM) model. The change of mass at the bottom of the pipe and gas velocity distribution was studied. It was found that, in the prophase of flow, centrifugal force is more dominant than circumferential friction; in the anaphase of flow, the opposite is true. In terms of gas velocity distribution and pressure distribution, pipe rotation with different speeds has the same action law to flow blockage collapse. Moreover, 300 rpm was found to be the optimal speed in our study, instead of the faster ones. It is trusted that the method reported in this paper will serve as a helping source for the upcoming studies towards the slug collapse of dense‐phase pneumatic conveying.