Numerical investigation of elbow erosion in the conveying of dry and wet particles

Liquid bridges between wet particles affect pneumatic elbow erosion, but the associated mechanism remains unclear. This paper presents a numerical study of elbow erosion using a combined approach of computational fluid dynamics and discrete element method facilitated with erosion and capillary force models. Particle dynamics and the elbow erosion location, depth and ratio are analysed in detail. The results show that wet particles tend to adhere to the inner wall of the elbow during transport under the effect of liquid bridges. This phenomenon forms a particle layer that covers the impact area, thereby substantially decreasing both the erosion depth and ratio of the elbow. A U-shaped erosion scar is observed in the extrados of the elbow when conveying wet particles. Additionally, the effects of gas velocity and moisture content on particle flow and elbow erosion are revealed to clarify the differences between dry and wet particles. (c) 2021 Elsevier B.V. All rights reserved.