Process Equipment and Plant Design MCQs

preferably flow inside the tube for its easier internal cleaning.

perferably flow outside the tube.

flow at a very slow velocity.

flow outside the tube, when the flow is counter-current and inside the tube when the flow is co-current.

5 to 10

15 to 30

40 to 50

55 to 75

Number of theorectical plates.

Static submergence.

Allowable vapour velocity.

Length of straight rectangular weir on cross-flow tray.

It is used for high viscosity liquor having large rate of scaling.

The tube bundle is suspended on bracket.

There is no central downtake.

Downtake is formed by the annular space between the bundle and the shell.

facilitate draining out liquid from a tray when the unit is not in operation.

are normally located near the overflow weir so that any delivery of liquid during operation follows approximately the same path as the overflow fluid.

must be large enough (usually 1/4″ to 5/8″ dia) to prevent plugging but should not deliver excessive amount of fluid during operation.

all (a), (b) and (c).

ferrule

socket

nipple

saddle

60

200

350

negligible

Generally, a skirt clerance of 0.5″ to 1.5′ is recommended to prevent plugging of the slots by residue build up.

The purpose of the slot is to disperse the gas into the liquid in the form of small bubbles.

If sufficient slot area is not provided, the gas may pass through the skirt clearance.

none of these.

it reduces heat transfer area.

more thinner tubes can be used.

pressure drop is reduced.

it makes condenser compact.

baffle spacing

clearance

pitch

none of these