CHEMICAL ENGINEERING- 2003 , PAPER –I, SECTION A

                             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 an incompressible fluid? Determine an expression for pressure drop in an incompressible fluid flowing in a pipe under the condition of laminar flow.

(b)   Discuss the working of a centrifugal pump along with its operational problems and remedial measures.

(c)    Describe the procedure to calculate number of equilibrium stages in the fractionation of a binary system by poncho- Savarit method.

(d)   Explain LMTD correction factor. How is it calculated in the case of multipass shell and tube heat exchangers?

(e)   Develop a relation between heat transfer coefficient and friction factor by using colburn analogy.

2.       (a) Discuss flow pattern caused by a turbine type impeller in an agitated tank and suggest ways to prevent swirling and vortex formation.

                      (b) Explain the principle of Pitot tube and its application. Also discuss how average velocity can be calculated?

                      (c)  Discuss the construction and operation of a notary drum filter. How is rate of filtration related to speed of rotation?

                     (d)  What is fluid energy mill? Explain its principle

3.       (a) Explain the term critical thickness of insulation Determine an expression for it for a spherical vessel.

                       (b) Saturated steam of atmospheric pressure condenses on a cold tube of 25 mm diameter and 1 m long. Determine per cent change in heat transfer rate if the orientation of tube is changed from horizontal to vertical.

                      (c) Compare forward feed double effect evaporator with backward feed double effect feed evaporator.

                      (d) Briefly discuss the procedure to calculate radiant heat load of an oil fired furnace.

4.       (a) Define diffusivity term. Discuss the method of measurement of diffusivity of a binary system in a laboratory.

                        (b) Describe the procedure to calculate minimum liquid gas ratio for absorbers.

                        (c) Discuss the working principle of a forced draft cooling tower.

                        (d) What are constant rate and falling rate periods in the drying of solids? Develop an expression for time of drying of a solid under falling rate period.