1. CONTINUOUS GRAVITY DECANTER
By:
DIMPLE PATEL ( )
Faculty: Krunal J. Suthar
Department of Chemical Engineering
Shroff S. R. Rotary Institute of Chemical Technology
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CONTENTS
Principle of decanter
Immiscible liquids
Continuous gravity decanter
Derivation of equation
Use of decanter in industry
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3. Active Learning Assignment SRICT/CE/FFO
PRINCIPLE OF DECANTER
Decanters used for the separation of two immiscible liquids of differing densities from one another.
The working principle of decanters is based on sedimentation or settling process.
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IMMISCIBLE LIQUIDS
Immiscible is the property where two substances are not capable of combining to from mixture.
Example..
Oil and water
Water and alcohol
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5. CONTINUOUS GRAVITY DECANTER
A continuous gravity decanter is used for the continuous separation of two immiscible liquids when the difference between densities of the two liquids is large.
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The feed mixture enters at one end of the separator, the two liquids flow slowly through the vessel separate into two layers, and discharge through overflow lines at the other end of the separator.
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Provided the overflow lines are so large that frictional resistance to the flow of the liquids is negligible.
The performance of the decanter can be analyzed by principle of fluid statics.
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Let the other densities of the heavy and light liquids be and respectively.
Let the interface between two liquids is at a height from the bottom of the vessel.
The total depth of the liquid of the vessel is and the depth of the layer of the light liquid is
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The overflow of the light liquid is at a height and the heavy liquid is at a height from the bottom of the vessel.
Assume that the overflow lines and the vessel itself are open to the atmosphere through a vent line.
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10. Active Learning Assignment SRICT/CE/FFO
Derivation of equation
A hydrostatic balance gives,
Where,
=depth of the light liquid
=interface between two liquids
=height of the overflow light liquid
=total depth of the liquid
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-----(1) -----(2) -----(3) -----(4)
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Substituting for from equation (4) into (2),
Collecting the terms, we get
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The above equation shows that the position of the interface between the layers in the separator depends on the elevation of the
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USE OF DECANTER IN INDUSTRY
Sugar industry
Wine industry
Pharmaceutical industry
Food industry
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15. Active Learning Assignment SRICT/CE/FFO
Thank you
Active Learning Assignment SRICT/CE/FFO