Fluid dynamics performance of phase change material particles in a Wurster spout

Correia, R., Paulo, B. B., Prata, A. S., & Ferreira, A. D. (2019). Fluid dynamics performance of phase change material particles in a Wurster spout–fluid bed. Particuology, 42, 163-175. https://doi.org/10.1016/j.partic.2018.05.001

Fluid dynamics performance of phase change material particles in a Wurster spout–fluid bed

Rui Correia ^a, Bruna Barbon Paulo ^b *, Ana Silvia Prata ^b, Almerindo D. Ferreira ^a

a ADAI-LAETA, Department of Mechanical Engineering, University of Coimbra, 3030-788, Coimbra, Portugal
b Department of Food Engineering, School of Food Engineering, State University of Campinas, 80 Monteiro Lobato Street, 13083-862, Campinas, Brazil

10.1016/j.partic.2018.05.001

Volume 42, February 2019, Pages 163-175

Received 25 October 2017, Revised 19 April 2018, Accepted 1 May 2018, Available online 13 September 2018, Version of Record 21 January 2019.

E-mail: brunabarbonpaulo@gmail.com

Highlights

• A simulation of fluid dynamics of PCM particles in a Wurster spout–fluid bed was performed.

• Higher air flow rate was appropriate for an upward movement of particles in Wurster tube.

• Uniform thermal profile lower than air inlet temperature was obtained experimentally in reactor.

Abstract

Spout–fluid-bed coating of solid–lipid materials, including some Phase Change Materials (PCMs), is a rarely used approach because of the probability of a phase change during the process. However, if mastered, this process could enable the commercialization of high-load PCM particles to develop new materials. An understanding of the thermal and fluid dynamics profiles inside a reactor can be used to establish optimized coating conditions, to avoid premature PCM melting and to maximize the drying rate. This research studies, through computational simulation, the behavior of particles and the experimental thermal profile inside a Wurster spout–fluid bed. A simplified model approach of momentum was simulated using OpenFOAM and carnauba wax particles as a PCM material. The simulation showed that appropriate flow conditions inside the Wurster tube must vary between 200 and 300 m³/h to ensure a better particle coating. The measured experimental thermal profile was uniform in the reactor and it was 5–10 °C lower than the set temperature. Thus, a maximum airflow at 70 °C that was used in the equipment is considered suitable for the further coating of PCM particles. The methodology proved useful for the preliminary identification of flow and temperature conditions in the spout–fluid process.

Graphical abstract

Keywords

Computational fluid dynamics; OpenFOAM; Simulation; Carnauba wax

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