CHEMICAL ENGINEERING – 2002, PAPER – I

Time Allowed: three Hours     Maximum Marks: 200

Candidates should attempt Questions 1 and 5 which are compulsory, and any THREE of the remaining questions, selecting at least ONE question from each Section.

Assume suitable data if considered necessary, and indicate the same clearly.

SECTION A

1.       Answer any four of the following :

          (a)    What is the physical significance of Bemoulli’s equation? How this equation by cans modified to account for friction losses?

          (b)   What are the laws of size reduction? Explain them, mentioning the ranges of their applicability.

          (c)    Discuss the procedure for evaluating mass transfers co-efficient using Wetted Wall Column.

          (d)   Discuss briefly the diffusion and capillary mechanisms involved in moisture movement in drying of solids.

          (e)   “By using the analogy suggested by Osbome Reynolds, develop a relation between heat transfer coefficient and friction factor.”

2.       (a) Considering fluid flow through a circular pipe, derive the Hagen- Posieuille equation.

                 (b)   Explain the principles of Pitot tube.

                 (c) List three industrial filters, specially indicating their applications.

                 (d)     Discuss the degree of mixing and determination of power of mixing.

3.          (a) Explain “point efficiency”. Murphree tray efficiency and overall tray efficiency.

                    (b) Explain how to calculate minimum liquid-gas ratio for absorbers.

                   (c)  Explain how you would determine number of stages for doubles solvent extraction.

                   (d)  Discuss Mier’s super saturation theory.

         4.  (A) what are the effects of various operating conditions on overall heat transfer coefficient in an evaporator unit?

              (b)  What do you understand by geometric shape factor in thermal radiation? Determine the geometric shape factor for a very small disc of area dA and larger parallel disc of area a located above the smaller one.

              (c)  Differentiate between equivalent diameters for heat transfer and pressure drop for flow of a fluid through the annulus of a double pipe heat exchanger.

              (d) With a neat sketch, describe briefly the scheme used or solar water heating.