Particle erosion in 90-Degree elbow pipe of pneumatic conveying System: Simulation and validation

Abstract

In this paper, a new comprehensive numerical model is proposed to investigate the particle erosion behaviors (PEBs) in 90-degree elbow pipe (90° EP) of pigsty feed pneumatic conveying system (PFPCS) for gas–solid two-phase flow (GSPF). Calculations of the Re-normalisation group (RNG) k-ε equation, pipeline heat transfer (PHT) equation, and particle tracking (PT) equation are coupled and solved in our model via computational fluid dynamics and discrete phase model (CFD-DPM). Notably, temperature effect, which is the thermophoretic force (FT) is considered and verified for enhancing the prediction accuracy of the erosion rate (η) in this model. Subsequently, this model is used to analyze the η influence of various factors, such as the impact angle (θ), the particle mass flow rate (mp), the particle injection velocity (v), the particle shape factor (κp), the particle diameter (Dp), on the performance of 90° EP of PFPCS. Simultaneously, a visual experimental system for temperature and pressure drop gradient of 90° EP is established for verification. The prediction results via our proposed erosion model are remarkably close to the experimental values by calculating, evaluating and comparing eight kinds of previous erosion models. Furthermore, ηmax increases as the surface temperature of (Text) increases, revealing the interaction between thermophoretic forces, gravity, and fluid drag. Moreover, ηmax initially decreases with the increase of Dp, and then increases when Dp is from 50 μm to 1000 μm, and ηmax increases linearly with the increase of mp. In addition, ηmax first increases with the increase of κp, and then decreases, and ηmax is 1.18 mg·m−2·s−1 at Text = 25℃, κp = 0.8. Therefore, this study provides a theoretical basis and high-performance numerical model for developing a real-time data transmission software, which forms a health monitoring system with the components of PFPCS.