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Reg No.: Name:

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

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Fifth Semester B.Tech Degree Regular and Supplementary Examination December 2020

Max. Marks: 100

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Course Code: CH303
Course Name: MASS TRANSFER OPERATIONS -I

Psychrometric chart and steam table are allowed
Graph sheets to be provided
PARTA
Answer any two full questions, each carries 20 marks.

Derive the equation for steady state diffusion in multi component mixtures.
Benzene is stored in a tank of diameter 10 m and open at the top. A stagnant air
film 10 mm thick is covering the surface liquid beyond which benzene is absent.
If the atmospheric temperature is 25°C and the corresponding vapour pressure is
150 mm Hg, Diffusivity of benzene is 0.02 ന (വ and total pressure is | atm.
Estimate the rate of loss of benzene.
Starting from fundamentals, derive an expression for the diffusion of A and B
under equimolal counter diffusion conditions.
Explain the method to find the number of stages in counter current cascade by
graphical method.
Explain with neat sketch principle and working of venturi scrubber and mention
its industrial applications.
Diffusivity of toluene is measured by Stefan’s method. A vertical glass tube of
3 mm diameter is filled with toluene to a depth of 19 mm from top open end.
After 275 hours at 37 °C and 1 atm. total pressure the level has fallen to 79 mm.
from top. Density of toluene is 850 kg/m? and Vapour Pressure 37 °C is 57.3 mm
Hg. Calculate the diffusivity of Toluene in air.
Explain flooding in packed bed absorption column.
With neat sketch, describe the constructional features and design constraints of a
packed tower.

PART 8

Answer any two full questions, each carries 15 marks.

Write a note on operating lines with graphs and indicates their positions for

absorption and stripping operations.

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Duration: 3 Hours

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