Mass Transfer Operations I — Winter 2023

Explain film theory for mass transfer coefficient.

Differentiate between packed towers and tray tower.

Derive Fick’s law of diffusion and explain NAand JA. Also prove that For unidirectional binary diffusion JA=-JB.

Define: (i)Flooding (ii)Priming (iii)Coning

Explain material balance for single stage extraction.

Discuss in detail classification of mass transfer operations and explain with examples.

Derive equations to calculate rate of steady state diffusion of ‘A’ through non-diffusing ‘B’ and also for steady state equimolal counter diffusion in case of gases.

Explain Meir’s theory for crystallization.

Define (i)Weeping (ii) Dumping (iii)Tray Spacing (iv)Theoretical Tray

Ammonia and air are in equimolal counter diffusion of each other in a cylindrical tube of 3 mm diameter and 20 m length. The total pressure is 1 atm and the temperature is 25 oC. One end of the tube is connected to a large reservoir of NH and the other end of the tube3 is open to atmosphere. Estimate the mass transfer rates in kg/sec of ammonia and air. The mass diffusivity of mixture is 0.28 x 10-4 m2/sec

Explain random packings and regular packing.

Explain selection criteria of solvent for gas absorption.

Explain equilateral–triangular co-ordinate, plaint point, tie line, one pair partially soluble system with examples and the mixture rule.

Discuss construction and working of Sparged Vessel.

Discuss local and overall mass transfer coefficients.

Explain selection criteria of solvent for extraction.

What is Extraction? Give the industrial applications of Extraction.

Explain mass, heat and momentum transfer analogies.

Enlist different leaching equipment and explain any one in detail with neat figure.1

Explain preparation of solids for leaching.

Explain material balance for single stage leaching.

Agas mixture containing 3% by volume pentane vapour and 97 % inerts. The mixture is treated with a non-volatile absorption oil in an absorber and 97 % removal is required. The feed solvent is free from solute. The feed gas rate is 50 kmol/hr. equilibrium relation is Y=0.25X/(1+0.75X). where Yand Xare mole ratio. Calculate minimum solvent required.

Explain diffusion in solids.

Explain construction and working agitated tank crystallizer with the help of a neat sketch.

5000 kg/hr of a SO -air mixture containing 5% by volume of SO is22 to be scrubbed with 2,00,000 kg/hr of water in a packed tower. The exit concentration of SO is reduced to 0.15%. The tower operates at2 1 atm. The equilibrium relation is given by: Y = 30 X. Y = Mole SO2 / Mole air; X = Mole SO / Mole water If the packed height of tower2 (Z) is 0.42 m, Calculate the height of transfer unit (HTU).