Maharashtra State Board of Technical Education 2008 Diploma Chemical Engineering Mechanical Operations - Question Paper

Sample ques. Paper – I
Course Name :- Diploma in Chemical Engineering
Course code :- CH
Semester :- Third
Subject :- Mechanical operations
Duration :- three hours Marks : 80


Instructions:

1) All the ques. are compulsory
2) Figures to the right indicate full marks
3) presume suitable additional data if necessary
4)Non-programmable pocket calculator is allowed


Q.1 Attempt any 8 (Marks 16)

a. Write down the principle involved in separation of solid mixture by froth flotation cell.

b. Which property is used for separation of solid mixtures by electrostatic precipitator?

c. What happens if ball mill is centrifuging?

d. State Rittinger’s legal regulations.

e. What is mesh number?

f. describe Electro dialysis.

g. Name 2 filter media’s used in filtration.

h. Why coagulants are used in sedimentation?

i. describe mixing.

j. describe ideal screen.


Q.2 Attempt any 3 (Marks 12)

a. describe (i) oversize & under size in screening (ii) Agitation.

b. Draw neat diagrams of washing & non-washing plates with flow connections of filtrate outlet and wash inlet of plate & frame filter press.

c. Classify the crushing & grinding equipments based on their principles of working.

d. Differentiate ranging from ideal screen & true screen on the basis of efficiency & separation effectiveness.


Q.3 Attempt any 3 (Marks 12)

a. Derive an expression for calculating the critical speed of a ball mill.

b. define the principle involved in hydraulic jig.

c. define the effect of the subsequent terms on rate of filtration (i) Area of filtration (ii) Viscosity.

d. define with neat diagram construction & working of Dorr Thickener.


Q.4 Attempt any 2 (Marks 16)

a. A mixture of 50 mesh, 100 mesh & 150 mesh size particles are to be separated. provide trommel arrangements for this with diagram.

b. define any 2 mixers used for (i) Solid-liquid mixing (ii) liquid-liquid mixing.

c. (i) For crushing rolls derive the formula cos alpha = (r + d) /(r + R) (ii) A crushing rolls one meter in diameter are set so that the crushing surfaces are 12.5 mm apart & angle of nip is 310 , what is the maximum size of particle which should be fed in the rolls.


Q.5 Attempt any 3 (Marks 12)

a. Draw 2 graphs to represent different methods of screen analysis.

b. Draw a neat diagram & define gas solid separation in a cyclone.

c. Draw a neat diagram & define the principle & working of any one-filtration equipment.

d. Draw diagram representing the batch sedimentation test in laboratory.


Q.6 Attempt any 3 (Marks 12)

a. define the principle & working of a magnetic separator.

b. State the formula for constant rate & constant pressure filtration. discuss the terms involved in it.

c. Differentiate ranging from filtration & sedimentation. (2 points)

d. define methods to avoid vortex formation during mixing.

Earning:   Approval pending.