Simulation of spray coating in a spouted bed using recurrence CFD (Open Access)--颗粒学报PARTICUOLOGY

Kieckhefen, P., Lichtenegger, T., Pietsch, S., Pirker, S., & Heinrich, S. (2019). Simulation of spray coating in a spouted bed using recurrence CFD. Particuology, 42, 92-103. https://doi.org/10.1016/j.partic.2018.01.008

Simulation of spray coating in a spouted bed using recurrence CFD (Open Access)

Paul Kieckhefen ^a *, Thomas Lichtenegger ^{b c}, Swantje Pietsch ^a, Stefan Pirker ^b, Stefan Heinrich ^a

a Institute of Solids Process Engineering and Particle Technology, Hamburg University of Technology, Hamburg, Germany
b Department for Particulate Flow Modelling, Johannes Kepler University, Linz, Austria
c Linz Institute of Technology (LIT), Johannes Kepler University, Linz, Austria

10.1016/j.partic.2018.01.008

Volume 42, February 2019, Pages 92-103

Received 1 November 2017, Revised 5 January 2018, Accepted 16 January 2018, Available online 25 June 2018, Version of Record 21 January 2019.

E-mail: paul.kieckhefen@tuhh.de

Highlights

• rCFD was used to time-extrapolate dynamics in 3D spouted beds simulated by CFD–DEM.

• Bed distribution and residence time in a spray zone were accurately reproduced by rCFD.

• Simulations of 1-h spray injection were performed to evaluate coating quality.

• The addition of draft plates resulted in a broader surface coverage distribution.

• A speedup of 2100 times was achieved compared with pure CFD–DEM.

Abstract

Although numerical models such as the computational fluid dynamics–discrete element method (CFD–DEM) have enabled the accurate simulation of laboratory-scale apparatuses, the application of these methods to large-scale apparatuses with many particles and time scales ranging from minutes to hours remains a challenge. The recently developed recurrence CFD (rCFD) method seeks to overcome these issues in pseudo-periodic processes by extrapolating globally recurring patterns in a physically meaningful way and describing the transport and interaction of passive scalars using Lagrangian tracers. Spouted beds represent an interesting target because of the associated variety of flow regimes. They can be effectively described by CFD–DEM on the time scale of tens of seconds, whereas industrially relevant processes typically take hours. In this contribution, we established the validity of applying the Lagrangian rCFD method to spouted beds by demonstrating the accurate reproduction of the particle residence time distribution in a fictitious spray zone. The deposition of spray droplets onto tracer particles was simulated for 1 h, and the particle surface coverage distribution was estimated using a statistical approach for both an unstabilized prismatic spouted bed and one stabilized by draft plates.

Graphical abstract

Keywords

CFD–DEM; Recurrence CFD; Spray coating; Time-scale decoupling; Spouted bed; Draft plate

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