Chemical Engineering Mcqs

Prandtl number for most of dry gases is about________________?

(A) 0.001
(B) 0.72
(C) 70
(D) 150

Submitted By :Ali Uppal

Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the________________?

(A) Less corrosion problems
(B) Flexibility possible in the baffle arrangement
(C) Low pressure drop
(D) High heat transfer co-efficient

Submitted By :Ali Uppal

The purpose of providing expansion bellows in the shell of tubular exchanger is to _____________________?

(A) Increase the heating load
(B) Impart structural strength
(C) Account for the uneven expansion of shell and tube bundles
(D) Facilitate increase of shell length, if needed

Submitted By :Ali Uppal

Multipass heat exchangers are used______________________?

(A) Because of simplicity of fabrication
(B) For low heat load
(C) To obtain higher heat transfer co-efficient and shorter tube
(D) To reduce the pressure drop

Submitted By :Ali Uppal

It is not recommended to use a 1-2 shell and tube heat exchanger for a particular heat duty, whenever the LMTD correction factor is___________________?

(A) > 0.75
(B) < 0.75
(C) < 0.50
(D) < 0.25

Submitted By :Ali Uppal

Finned tube heat exchangers__________________?

(A) Give larger area per tube
(B) Use metal fins of low thermal conductivity
(C) Facilitate very large temperature drop through tube wall
(D) Are used for smaller heat load

Submitted By :Ali Uppal

Fruit juice (a heat sensitive material) can be concentrated in a ____________ evaporator?

(A) Long tube
(B) Falling film
(C) High pressure
(D) None of these

Submitted By :Ali Uppal

The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re0.8, where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter D. as _________________?

(A) D-1.8
(B) D-0.2
(C) D0.2
(D) D1.8

Submitted By :Ali Uppal

In case of a multipass shell and tube heat exchanger, the temperature drop in the fluid _______________?

(A) Is inversely proportional to the resistance across which the drop occurs
(B) And the wall are proportional to individual resistances
(C) And the wall is not related
(D) None of these

Submitted By :Ali Uppal

The capacity of double-effect evaporator is less than half of the capacity of two single effects, each of which is operating over same terminal temperature difference, when the________________ ?

(A) Solution has an elevation of boiling point
(B) Evaporators operate under vacuum
(C) Evaporators operate at atmospheric pressure
(D) None of these

Submitted By :Ali Uppal

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