The influence of surface-wall roughness on hydrocyclone performance
Arjun Kumar Pukkella, Dennis Vega-Garcia, Kathryn Hadler, J.J. Cilliers
Abstract
The impact of hydrocyclone design and operation on particle separation has been extensively studied. However, scant attention has been paid to wall surface roughness , despite its relevance to industrial scenarios. This study investigates the influence of surface-wall roughness on hydrocyclone performance through Computational Fluid Dynamics (CFD) modeling and experimental analysis. Flow properties and particle separation characteristics between smooth and rough-surfaced hydrocyclones at various flow rates were investigated. CFD analysis reveals a threshold surface-wall roughness above which underflow water recovery significantly increases. Additionally, the axial, tangential, and radial velocities , as well as pressure distribution profiles, exhibit distinct trends for smooth and progressively rough hydrocyclones. Experimental studies were conducted on 75 mm diameter hydrocyclones, 3D-printed with three different degrees of surface roughness for water-only and 5% solids conditions. The experimental observations support the trends predicted by CFD. Rough-surfaced hydrocyclones demonstrate significantly higher underflow solids recoveries, with values increasing up to 58%, compared to 46% for smooth-surfaced hydrocyclones at a flow rate of 1000 mL/s. At the highest flow rate of 1500 mL/s, rough-surface hydrocyclones show a 27% higher underflow solids recovery than smooth designs. Additionally, rough-surfaced hydrocyclones achieved higher underflow solids concentration at increased flowrates compared to smooth hydrocyclones, with concentration ratios ranging from 1.36% to 2.2% compared to 1.44% to 1.93% for smooth surfaces. These findings underscore the complex interplay between flow dynamics and particle separation in hydrocyclones, highlighting the potential of surface-wall roughness to enhance separation performance. These findings are important in maintaining and improving hydrocyclone performance in industrial applications requiring dewatering applications and high solids recovery.