PDF Emulsion Processing - Homogenization - UMass
[Pages:50]Emulsion Processing - Homogenization -
Jochen Weiss
*Food Structure and Functionality Laboratories Department of Food Science & Biotechnology University of Hohenheim Garbenstrasse 21, 70599 Stuttgart, Germany
Emulsion Workshop November 13-14th, 2008, Amherst, MA
1
Principle of Emulsion Formation
Primary Homogenization
Oil
Secondary Homogenization
Water
Premix
2
Emulsion Processing: Homogenizers
Oil
Water
Homogenizer
Homogenization is a unit operation using a class of processing equipment referred to as homogenizers that are geared towards
reducing the size of droplets in liquid-liquid dispersions
3
Physiochemical Processes Occurring During Homogenization
Continuous phase
Droplet Deformation
Rapid adsorption: Stable droplets
Emulsifier
Disruption
Dispersed phase
I. Prehomogenization
II. Homogenization
Slow adsorption: Coalescence
III. Stabilization
4
General Homogenization Options
(A)
(B)
The order of ingredient addition and homogenization may have a large impact on product properties
5
Homogenization: Process Parameters
Energy density
- minimum droplet size achievable
Energy efficiency
- heat losses - manufacturing costs
Volume Flow Rates
- throughput - production time
Product rheology
- limitations - materials that can be homogenized
6
The Physics of Droplet Disruption
? Maintaining Force. Drop shape maintenance forces (Laplace Pressure)
? Disruptive Force. Drop disruption is due to drop-surface applied tangential stresses
? Weber-Number (We): The ratio between drop disrupting and drop maintaining forces, drop disruption occurs only above a critical Weber number
? We < Wecrit or tbr < tbr,crit droplet deformation
? We > Wecrit or tbr > tbr,crit droplet disruption
? Deformation Time. Droplets must be exposed to tangential stresses for a sufficient amount of time
pc
=
1 r1
+
1 r2
=
4 d
d
We = =
pc 4
tbr ,crit
=
d
- pc
Key Parameter: Energy Density Ev
Energy input E
P
Ev = homogenized volume V = V& = Pvtv
? The volume specific energy input or the energy density Ev can simply be calculated from the power consumption and the volume flow rate
? The mean droplet diameter may often be empirically related to the energy density, IF, all other parameters are kept constant!
( ) x1,2 = C Ev b
8
................
................
In order to avoid copyright disputes, this page is only a partial summary.
To fulfill the demand for quickly locating and searching documents.
It is intelligent file search solution for home and business.
Related download
- pdf safety data sheet wd40 aerosol lite alt
- pdf sage crea ons organic farm
- docx commonly used sheltering items services listing
- pdf kickoff for kindness blessing bag project
- pdf household hazardous waste in the sanitary landfill
- pdf clariant products for wetwipes
- pdf emulsion stability and testing
- pdf material safety data sheet
- pdf how to start your own soap business
- pdf concentrations and dilutions pearson education
Related searches
- umass online courses spring 2019
- umass boston online course
- online courses umass amherst
- umass amherst summer online courses
- umass online degrees
- umass course list
- umass course catalog spring 2020
- umass amherst online courses
- acrylic emulsion sds
- umass online classes
- umass boston online degree programs
- umass amherst summer session 2020