CFD-DEM Investigation of Spout Stabilization by Large-Particle Addition
Abstract
Stable spouting of small particles is critical in fluidized-bed chemical vapor deposition (FB-CVD), but spout deflection, channeling, and irregular flow often occur. In this study, cold-model experiments and CFD-DEM simulations were combined to investigate the effects of particle diameter and density on spouting stability in a pseudotwo-dimensional (pseudo-2D) spouted bed. Particles of four materials were tested at different diameters: glass beads (2.6 g/cm3), ZrO2 (5.6 g/cm3), Fe (7.8 g/cm3), and UO2 (10.8 g/cm3). Unstable, transitional, and stable regimes were classified by power spectral density (PSD) analysis of pressure-drop fluctuations. Under the tested conditions, more stable spouting was obtained with larger or denser particles. In an unstable small-particle ZrO2 system, spout deflection was progressively suppressed by adding large particles. A PSD peak power-diameter ratio-density stability phase diagram was constructed for the tested conditions. Three coupled stabilization mechanisms were further identified by the CFD-DEM simulations. Momentum exchange and kinetic energy dissipation were increased through large-small collisions. Drag was distributed more uniformly in the spout. Local high-velocity channels and spout deflection were consequently suppressed, and centerline-symmetric particle circulation was established. These results provide laboratory-scale mechanistic evidence for stabilizing small, high-density particles under cold-model conditions. They also…
Read the paper
Related studies
- eggNOG 5.0: a hierarchical, functionally and phylogenetically annotated orthology resource based on 5090 organisms and 2502 viruses
- Online Survival Analysis Software to Assess the Prognostic Value of Biomarkers Using Transcriptomic Data in Non-Small-Cell Lung Cancer
- OptiType: precision HLA typing from next-generation sequencing data
- Nicotinic Cholinergic System and COVID-19: In Silico Identification of an Interaction between SARS-CoV-2 and Nicotinic Receptors with Potential Therapeutic Targeting Implications
- Saccharomyces cerevisiae cells have three Omega class glutathione S-transferases acting as 1-Cys thiol transferases
- Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.