Analysis of the effect of geometric and flow parameters on the separation efficiency of virtual impact separators: Optimization based on response surface methodology

Abstract

Respiratory dust is the primary factor triggering pneumoconiosis. Accurately separating respiratory dust from total dust according to specific criteria are key aspects of respiratory dust monitoring and prevention technology. In this study, we numerically solve the gas-solid two-phase flow within a virtual impactor by coupling computational fluid dynamics (CFD) with the discrete element method (DEM). Here, we explored the air velocity and dust separation efficiency of each component of the virtual impactor to determine optimal structural scale parameters. Accurate 3D printing technology was employed to materialize the three-dimensional structure of the virtual impactor. The separation efficiency of the virtual impactor was evaluated and verified through simulated duct experiments. The results indicate that the weak flow ratio has the most significant effect on separation efficiency, followed by the effect of the ratio of separation chamber diameter to nozzle width (S/W), the ratio of the weak flow outlet size to nozzle width (D/W) aving the smallest degree of influence. When S/W is 1.8, D/W is 1.333, and the weak flow ratio is 0.1, the separation efficiency curves show optimal performance, as confirmed by experimental verification. The experimental verification matched the simulated separation efficiency data within a deviation range of 1.10–11.4 %.