Entrained air by particle plume: comparison between theoretical derivation and numerical analysis

Abstract

Industrial bulk material transfer and handling processes often cause large amounts of dust emission and seriously threatens workers' health. Proper design of dust removal system requires an understanding of the volume flow rate of entrained air during the falling process of the particle plume. Based on previous researches, this paper deduces the formula of the volume flow rate of entrained air through theoretical analysis. This theoretical formula involves the initial velocity of the particles and the void fraction of particle plume core zone. By comparing with former experimental and numerical calculation results, it is found that the theoretical formula can better predict the volume flow rate of entrained air. The numerical calculation is used to analyze the influence of the initial velocity of the particles and the angle of the particle source on the volume flow rate of entrained air. It was found that when the initial velocity of the particles increased from 0.1 m/s to 10 m/s, the volume flow rate of entrained air is hardly affected during the falling process. The angle between the particle source and the horizontal direction has a greater influence on the total volume flow rate of entrained air. With the angle of particle source between 30° and 45°, the total volume flow rate of entrained air is the largest for different drop height.