Analysis of gas-solid flow characteristics in intricate pipelines

Pneumatically conveying powder particles is predominantly employed in pipelines. Transportation variables significantly alter the behavior of powder particles within complex pipelines. To investigate the gas-solid two-phase flow characteristics of powder particles in dense phase within complex pipelines, Computational fluid dynamics and Discrete element model (CFD-DEM) were applied to the multi-opening pipelines for numerical simulation. The study examines the impact of gas velocity, particle mass flow rate, and particle size on the flow properties of solid-phase particles. It reveals that the particle velocity does not notably elevate as conveying gas velocity increases in the dense phase transportation of complex pipelines; Particle transport continuity is degraded at low mass flow rates, whereas higher filling rates are observed at high mass flow rates; With increasing particle size, particle inertia force escalates, leading to decreased particle velocity and conveying efficiency. The CFD-DEM method enables accurate portrayal of particle flow properties, offering a valuable reference for examining pneumatic conveying in complex pipelines.