Title
Study of the effect of flow intensity and flow geometry on the breakage of whey protein aggregates using CFD
Date Issued
01 December 2006
Access level
metadata only access
Resource Type
conference paper
Author(s)
Department of Process and Chemical Engineering, University College
Abstract
Experimental investigation coupled with CFD simulations allow us to conclude that aggregate breakage occurs all along the pipeline if the flow intensity is high enough and not only at the pipe diameter reduction as has been previously claimed by other researchers. A precipitate dispersion was propelled trough a pipe ID 0.736 mm at different flow velocities (5-17 ms-1) in order to study how flow intensity affects particle breakage. The dispersion was recycled several times to investigate the effect of the exposure time on particle size reduction. Particle size reduction through different flow geometries was investigated: 60 mm straight pipe, 60 mm+45° bend, 100 mm straight pipe, 100 mm+elbow and 1000 mm straight pipe. The flow field for each experimental flow geometry was modelled using the standard κ-ε turbulent model. Particle breakage was found to be different for each flow geometry and each flow intensity. Particle diameter reduction (Δd) was coupled with both the exposure time (Δt) and the dissipation rate (ε), and hence a breakage model of the form; Δd=k*Δt*(εiεth)/(εth)n was proposed. Here the term εi-εth is the driving force that leads to the breakage and it is the difference between the local dissipation εj and the maximum energy dissipation εth that a particle with a given size can withstand before any breakage occurs. The model was validated using both the CFD results and the experimental results for different flow geometries.
Language
English
OCDE Knowledge area
Física de partículas, Campos de la Física
Química física
Subjects
Scopus EID
2-s2.0-56849087133
Resource of which it is part
AIChE Annual Meeting, Conference Proceedings
Conference
2006 AIChE Spring National Meeting - 5th World Congress on Particle Technology
Sources of information:
Directorio de Producción Científica
Scopus