CPFD modeling and experimental validation of gas–solid flow in a down flow reactor. (12th July 2016)

• Record Type: Journal Article
• Authors: Lanza, A.; Islam, M.A.; de Lasa, H.
• Is Part Of: Computers & chemical engineering. Volume 90(2016)
• Page Start: 79
• Page End: 93
• Publication Date: 2016-07-12
• Subjects: Fluidized downer unit -- Computational Particle Fluid Dynamics -- Particle clusters; Chemical engineering -- Data processing -- Periodicals; 660.0285
• DOI: 10.1016/j.compchemeng.2016.04.007
• Languages: English
• ISSNs: 0098-1354

Abstract

Graphical abstract: Highlights: We studied gas–solid fluid dynamics in the developed region of a downer unit. We simulated particle–fluid flow using CPFD Barracuda software. We considered a random particle selection for cluster formation in the CPFD model. We studied cluster size distributions for a CPFD model with experimental data. We validated the computational model using a wide range of operating conditions. Abstract: This manuscript reports the fluid dynamics in the developed flow region of a cocurrent gas–solid down flow fluidized bed unit. Gas–solid flows are simulated using a Computational Particle Fluid Dynamics (CPFD) numerical scheme and experimental data from the CREC-GS-Optiprobes. This model represents clusters in a downer unit. It is hypothesized that in downers, clusters are formed via a Random Particle-Selection Method (RPSM) ensuring cluster dynamic stability. To accomplish this, a statistical particle-selection of clusters (SPSC) method is developed. This hybrid model is validated with experimental data obtained in a 2 m height and 2.57 cm diameter column. Observed time-averaged axial and radial velocities and solid concentration profiles are successfully simulated by the Hybrid CPFD / CREC - GS - Optiprobes Data Model . These findings support: (a) a narrow distribution of particle cluster residences, (b) the relatively flat radial solid concentrations and solid cluster velocities, and (c) a valuable approach for establishing slip velocities in downer units.