Studying the effects of adsorption, recoalescence and fragmentation in a high pressure homogenizer using a dynamic simulation model

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Abstract

The emulsification in a high pressure homogenizer was studied using a dynamic simulation model based
on the population balance equation. The model includes fragmentation, recoalescence and adsorption of
macromolecular emulsifier and uses a simple flow model in order to link the hydrodynamics in the
homogenizer to the three physical processes mentioned above.
A computer model offers an interesting opportunity to study the effect of model assumptions on the
overall outcome of the process. The computer model is also an interesting complement to experiments in
this case since internal measurements in the active region of homogenization are very hard to carry out,
due to small scales and high forces, and information on the spatial position of the different processes is of
great importance in design.
Based on a set of assumptions, mainly that the turbulent jet responsible for break-up can be described by
a one dimensional model and that the macromolecular emulsifiers hindrance of recoalescence can be
described by a wall like repulsion, it is shown that the active region of homogenization can be divided
into two zones; a narrow zone with fast fragmentation and nearly no recoalescence in the most intense
part of the region followed by a recoalescence zone as drop–drop interactions starts to dominate with
decreasing turbulence intensity. The effect of operating parameters is seen to be close to the ones found
from experiment.
The results are discussed in relation to a flow field obtained by a simplistic CFD and assumptions made
about hydrodynamics and emulsifier behavior.

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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Food Engineering

Keywords

  • High pressure homogenization, Emulsification, Recoalescence, Fragmentation, Adsorption of emulsifiers, Population balance equation
Original languageEnglish
Pages (from-to)1177-1183
JournalFood Hydrocolloids
Volume23
Issue number4
Publication statusPublished - 2009
Publication categoryResearch
Peer-reviewedYes