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The Effect of Various Design Variables on the Separation of Two Immiscible Liquids by Continuous Gravity Decantation

<p> The separation of distilled water and
coconut fatty acid (CNFA) was investigated
in a 4 in. x 16 in. vertical gravity decanter to determine the
most significant design variables. The design variables studied
were tangential versus perpendicular feed flow, height/diameter
ratio, the total feed flow rate, the temperature and the intertace
position with respect to feed inlet. The criteria used
were the calculated immiscible concentration of water in CNFA
overflow (Cw) and that of CNFA in water underflow (Co), The
test conditions were arranged according to a Central Composite
Design based on Box Method of Experimentation. Two levels of
inlet geometry and five levels of each of the other four variables
were studied. The range of variables were
1. Inlet geometry Tangential and Perpendicular Feed Flow
2. Height/Diameter Ratio 3/1 to 4/1
3· Total Feed Flow rate 160 cc/min. to 320 cc/min.
4. Temperature 40° to 80°c.
5· Interrace Position 2" below feed inlet to 2" above
feed inlet The Overall residence time in the decanter ranged from 7.5 to 12.5 minutes. The drop size distribution of the incoming dispersion was measured by taking photomicrographs for all the runs. </p> <p> It was found that the tangential feed flow was slightly better but not significantly better for the separation of two immiscible liquids. Statistical analysis revealed that 95% confidence level height/diameter ratio, flow rate and temperature, respectively, are the most important design variables for the separation of CNFA from water underflow. The dependence of Cw on height/diameter ratio of Co on the interface position was interpreted to mean that the theoretical, plug flow residence time within each phase is the most important design variable. Interaction between variables and second order constants were not found significant at 95% confidence level. Sedimentation rather than coalescence appeared to be the controlling factor in the present study. </p> / Thesis / Master of Engineering (MEngr)

Identiferoai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/19625
Date10 1900
CreatorsManchanda, Krishan
ContributorsWoods, D. R., Chemical Engineering
Source SetsMcMaster University
LanguageEnglish
Detected LanguageEnglish

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