Study on particle deposition and flow characteristics of edible chili oil in bending pipe conveyance in industrial production.

Abstract

This study develops a coupled computational fluid dynamics (CFD) and discrete element method (DEM) two-phase flow model to investigate particle deposition behaviors in industrial pipeline transportation of edible chili oil, a high-viscosity fluid widely used in food industries. Due to its complex rheological properties and the presence of suspended solids, chili oil pipelines frequently face significant challenges, including excessive particle deposition at pipe bends, increased pressure drops, and energy inefficiency. To address these critical issues, simulations were systematically conducted using the Realizable k-ε turbulence model, examining the effects of different inlet velocities (0.5-2.5 m/s), particle sizes (2-4 mm), and particle shapes (spherical, rod-shaped, and cubic). Results showed that operating the pipeline within an optimal transport velocity range of approximately 1.0-1.5 m/s effectively minimized particle accumulation at bends and significantly reduced pressure losses. Quantitatively, spherical particles exhibited the lowest pressure drop increase (from approximately 3.45 kPa at 0.5 m/s to 21.78 kPa at 2.5 m/s) due to reduced collision frequencies and kinetic energy dissipation. In contrast, irregular particles (cubic shapes) led to the highest pressure drops, rising sharply from 5.91 kPa at 0.5 m/s up to 34.56 kPa at 2.5 m/s, caused by frequent collisions and turbulent fluctuations. Additionally, simulations revealed that increasing particle size from 2 to 4 mm notably decreased particle deposition and pressure losses due to reduced collision frequency and enhanced momentum transfer. These quantitative findings not only fill the research gap concerning high-viscosity, particulate-laden edible fluid systems but also provide concrete and practical guidelines for optimizing chili oil transport processes. The findings directly contribute to improved operational reliability, lower energy consumption, and reduced blockage risks in industrial food pipeline applications.