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• Trays arenumbered from top to bottom as convention
• Section above the feed tray: Rectifying section
• Section below the feed tray: Stripping section
• Feed can be on any tray, but for better separation, we must
choose appropriate tray for feed input
• Feed can be liquid/vapor or a mixture
• Distillate/overhead product can be liquid or a mixture of liquid
and vapor
• It depends on the type of condenser (partial/total)
Fractional distillation unit (Fractionator)
• Continuous distillation
2.
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Fractional distillation unit(Fractionator)
• The flow rate, composition and condition of the feed
• The required degree of separation (i.e., purity of the products)
• The reflux ratio and the condition of the reflux
Important variables, parameters and factors involved in the design
3.
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Determination of thenumber of trays by McCabe-Thiele Method
Warren Lee McCabe
He was an American Physical Chemist and is
considered as one of the founding fathers of
the profession of chemical engineering
He was faculty at the Massa
chusetts Institute
of Technology
Ernest Thiele
An influential chemical engineering researcher
at Standard Oil (then Amoco, now BP) and
Professor of Chemical Engineering at the
University of Notre Dame.
He is known for McCabe-Thiele method,
Thiele Modulus
He is author of “Unit Operations of Chemical
Engineering”
A graphical method of design for fractionating (i.e., distillation) columns as a transformational publication in
Industrial and Engineering Chemistry in 1925
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Determination of thenumber of trays by McCabe-Thiele Method
It is graphical procedure.
It needs equilibrium x-y diagram and operating line equations
1. Operating line for rectifying section
