An adequate clearance between the tray and the shell wall of a distillation column is provided to

drain the liquid from the tray when the unit is not in operation.
allow for thermal expansion and facilitate installation.
avoid back-trapping.
none of these.
✅ The correct answer is option B.

A head comprises of straight flange section, corner torus, section and central dished section. Crown radius and knuckle radius in a head is related respectively to the

central dished section and corner torus section.
corner torus section and central dished section.
central dished section and straight flange section.
straight flange section and corner torus section.
✅ The correct answer is option A.

Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger

permits the use of less tubes in a given shell diameter.
facilitates comparatively easier external cleaning because of large clearance.
permits the use of more tubes in a given shell diameter.
both (b) and (c).
✅ The correct answer is option C.