New perspectives on capturing particle agglomerates in CFD modeling of spray dryers

Hasan Jubaer, Rui Dai, Erwin Ruslim, Shahnaz Mansouri, Zhihua Shan, Meng Wai Woo

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)

Abstract

Current computational fluid dynamic (CFD) models of spray dryers lack the capability to predict the structure of the agglomerates formed; loose or compact agglomerates. This is mainly due to the conventional simplistic approach in numerically “fusing” of the colliding particles forming the agglomerate. A new theoretical treatment is introduced in this work, suitable for implementation in CFD simulations, which numerically fuses the particles and yet retain information on the structure of the agglomerate. This new theoretical treatment is based on tracking the reduction of the agglomerate surface area as the agglomerate is progressively formed. Analysis revealed that the reduction in the agglomerate surface area exhibits a unified correlation with the degree of compactness of the agglomerate. Further analysis comparing this new approach to the conventional numerical fusing of the particles revealed inherent numerical discrepancies, which has not been noted in the literature before. Understanding these discrepancies will provide clarity to the interpretation of the modelling and simulation of spray drying particle agglomeration in CFD. Moreover, this work lays the groundwork for a more comprehensive CFD model for agglomeration which can be potentially utilized to predict final powder properties.

Original languageEnglish
Pages (from-to)685-694
Number of pages10
JournalDrying Technology
Volume38
Issue number5-6
DOIs
Publication statusPublished - 2020

Keywords

  • agglomerate surface area
  • agglomeration
  • CFD
  • Eulerian–Lagrangian
  • penetration depth
  • Spray drying

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