The Experiment of the Clog Reduction in a Plane Silo

J.Y. Delenne,F. Radjai,Jie Zhang,S. Nezamabadi,Ai-Le Sun,S. Luding

doi:10.1051/epjconf/201714003024

Abstract

The flow of particles may be clogged when they pass through a narrow orifice. Many factors can change the probability of clogging, such as the outlet size, the presence of obstacles and external perturbation, but the detailed mechanisms are still unclear. In this paper, we present an experimental study of reduction of the clogging probability in a horizontal plane silo, which consists of a layer of elastic particles transported on an annular flat plate rotating with a constant angular velocity passing through a hopper structure. We found the exponential distributions of the avalanche size for different sizes of orifice and the power law tails of the passing time between two particles. We did not confirm whether there was a critical size of orifice above which the clogging became impossible. We explored the effect of the obstacle on the probability of clogging: and if we chose a proper obstacle placed at a proper position, the probability of clogging could be reduced by a factor of about seven.

Highlights

Granular materials are very common in our daily life, such as sand, powder, cement, where the motions of particles due to thermal fluctuations are negligible[1, 2]
We found that the survival had a power law tail, which is consistent with the results of Zuriguel et al.[17]
We presented an experimental study of reduction of the probability in a plane silo by changing the ratio of outlet vs particles by the presence of an obstacle

Summary

Introduction

Granular materials are very common in our daily life, such as sand, powder, cement, where the motions of particles due to thermal fluctuations are negligible[1, 2]. When lots of granular particles pass through a small orifice, the flow of particles could be abruptly arrested, i.e. clogged. This phenomenon is ubiquitous and has be observed in many systems, such as granular flows in a hopper [3,4,5,6,7], dense suspension flows in a micro-channel [8], emulsions [9, 10], dense colloidal systems [11], and living animals [12]. When in an emergency, people rush to escape through a narrow exit, the clog may appear [13]

Methods

Results

Conclusion