Effect of emulsification conditions on mean drop size

1
Effect of emulsification conditions on mean drop
size

• Ivan. B. Ivanov, Nina Vankova, Slavka Tcholakova,
  
• Vasko Vulchev, and Nikolai D. Denkov
• Faculty of Chemistry, Sofia University,Sofia,
  Bulgaria

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Aim

• To determine the effects of different factors on
  the mean drop size
• Construction of the processing elements
• Viscosity of the oil phase
• Viscosity of the aqueous phase

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Emulsification method
Experimental set-up
Used processing elements
Two consecutive slits with 1 mm length
One slit with 1 mm length
One slit with 2 mm length
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Effect of the construction of processing element
on the mean drop size
Variations in the constructions of the processing
elements lead to 20 increase of the flow
rate 10 decrease of d32
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Effect of the construction of processing element
on the mean drop size
From the experiment we know p and Q. Assuming
VDISS const ? ? pQ/VDISS
Ratio of d32/dk
The studied constructions of the processing
elements do not affect VDISS
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Effect of the viscosity of the oil phase
Deformation time
For effective emulsification tRES should be at
least 10 times longer than ?DEF
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Emulsification in viscous turbulent flow
Hexadecane 1 wt WPC 60 Sugar, ?C 16.6
mPa.s
Size of the smallest eddies
Drop diameter in viscous turbulent flow
VDISS for viscous turbulent flow is close to
VDISS for inertial turbulent flow
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• Conclusions
• The studied constructions of the processing
  element do not affect significantly the
  hydrodynamic conditions and the emulsification
  efficiency.
• The successful emulsification of oils with
  moderate viscosity ( 600 mPa.s), requires
  longer emulsification time and/or higher driving
  pressure.
• The increase of the viscosity of the aqueous
  phase above ca. 13 mPa.s leads to emulsification
  in viscous turbulent regime (VDISS remains almost
  the same).