3. For a cylindrical shell, (subject to the thickness of uppermost course being more than the minimum for diaofthe tank in question), the thickness of the courses of shell
Options
A. decreases upwards.
B. increases upwards.
C. remains same throughout.
D. may decrease or increase upwards depending upon whether vacuum or positive pressure would be maintained inside the shell.
Correct Answer: Liquor flows inside the tube, while the steam is outside submerging the tube.
5. In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate)0.8. This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to
7. The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the __________ stress.
Correct Answer: Higher pressure fluid stream should be routed through the shell side.
9. In a multiple effect evaporator system having 'n' effects, the amount of water evaporated per unit surface area in approximately equal to __________ times that in a single effect.
10. Pick out the wrong statement about distillation operation
Options
A. Distillation under vacuum is a substitute for steam distillation.
B. In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation.
C. In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other.
D. Flash distillation, differential distillation & steam distillation are all continuous distillation processes.