Experimental and numerical analysis of hopper dust suppression during discharge of free falling bulk solids

Dust pollution related to the discharge of hoppers has drawn the attention from industries dealing with bulk solids handling. This paper presents an experimental setup to measure the dust concentration of dust suppression hoppers (DSHs) with various geometries and investigate the dust influencing factors. To understand the interactions of the bulk solids and entrained air during discharge, a coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) method is developed. The behaviour of the bulk solid particles and airflow is studied numerically. Results show that DSHs with a central plug of the bulk solid suppress dust by minimising the air entrainment within the particle flow, compacting the particle flow and reducing the velocities of the particles and airflow. Moreover, hopper geometries including the hopper half angle, outlet opening and outlet diameter can have significant influences on the performance of dust suppression. [Display omitted] •Experiments are conducted to obtain dust performance of different hoppers;•A coupled CFD-DEM model is developed to analyse particle and air behaviour;•Dust suppression hoppers take effect by optimising particle flow and airflow;•Dust is sensitive to hopper half angle, outlet opening and diameter.