21. In shell and tube heat exchangers, straight tie rods are used to
hold baffle in space.
fix the tubes in position.
account for thermal strain.
none of these.
✅ The correct answer is option A.
Process Equipment and Plant Design MCQs
22. Corrosion allowance in the design of pressure vessel/chemical equipment is not necessary, if
plain carbon steel and cast iron parts are used.
wall thickness is > 30 mm.
material of construction is high alloy steel.
both(b) & (c).
✅ The correct answer is option D.
23. In case of a continuous distillation column, increase in reflux ratio may result in the
lower fixed charges for the column.
greater cost for the reboiler heat supply.
greater cost for the condenser coolant.
all (a), (b) and (c).
✅ The correct answer is option D.
24. Overall tray efficiency of a distillation column is the ratio of the number of
overall gas transfer units to the number of ideal trays required.
ideal trays required to the number of real trays required.
real trays required to the number of ideal trays required.
none of these.
✅ The correct answer is option B.
25. Pick out the wrong statement pertaining to the use of valve tray, seive tray and bubble cap trays in continuous distillation column.
Bubble cap trays though most expensive are the best in situations, where low vapour rates is to be handled and a positive liquid seal is essential at all flow rates.
Murphree efficiency of all the three trays are nearly equal, however the peak efficiency is generally higher for seive and valve trays than the bubble cap.
Maintenance cost for valve and seive trays are comparatively more than bubble cap tray due to their relatively complicated construction features.
Valve trays have the highest turn down ratio (i.e. the ratio of the highest to the lowest vapour flow rates) and thus provides the maximum flexible operating range.
✅ The correct answer is option C.
26. A rivetted joint does not fail by __________ of rivets.
tearing
shearing
tearing of the plate across a row
none of these
✅ The correct answer is option D.
27. The minimum tray spacing in distillation column of diameter less than 3 ft is normally __________ inches.
6
18
24
34
✅ The correct answer is option A.
28. Shortest distance between two tubes is
called tube pitch.
called tube clearance.
more in case of triangular pitch as compared to square pitch of tube layout.
none of these.
✅ The correct answer is option B.
29. Nominal size of a pipe is an indication of its __________ diameter.
inner
outer
approximate
none of these
✅ The correct answer is option C.
30. If ‘D’ is the inside diameter of the shell of a shell and tube heat exchanger, then the baffle spacing is usually in the range of
D/2 or minimum 2″ to 5D.
D/5 or minimum 2″ to 5D.
D/5 or minimum 2″ to D.
none of these.
✅ The correct answer is option B.