CHEMICAL ENGINEERING

Question: In a gas-liquid shell and tube heat exchanger, the
[A].

presence of a non-condensible gas decreases the condensing film co-efficient.

[B].

gases under high pressure are routed through the tube side, because high pressure gases are corrosive in nature.

[C].

gases to be heated/cooled is normally routed through the shell side, because the corrosion caused by the cooling water or steam condensate remain localised to the tubes.

[D].

all ‘a’, ‘b’ & ‘c’

Answer: Option D

Explanation:

No answer description available for this question.

Question: Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone.
[A].

laminar

[B].

transition

[C].

both ‘a’ & ‘b’

[D].

highly turbulent

Answer: Option D

Explanation:

No answer description available for this question.

Question: jH factor for heat transfer depends upon the __________ number.
[A].

Biot

[B].

Nusselt

[C].

Reynolds

[D].

Prandtl

Answer: Option C

Explanation:

No answer description available for this question.

Question: Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is
[A].

in the central core of the fluid.

[B].

uniformly distributed throughout the fluid.

[C].

mainly confined to a thin film of fluid near the surface.

[D].

none of these.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Heat transfer by conduction results due to the transfer of free electrons, kinetic energy & vibrational energy from one molecule to another. Conduction heat transfer can not take place
[A].

between two bodies in physical contact with each other.

[B].

between two bodies not in physical contact with each other.

[C].

from one part of a body to the another part of the same body.

[D].

both ‘b’ & ‘c’

Answer: Option B

Explanation:

No answer description available for this question.

Question: Among liquids, water has a comparatively high value of thermal conductivity, due to its
[A].

low density

[B].

high viscosity

[C].

partial ionisation

[D].

dense structure

Answer: Option C

Explanation:

No answer description available for this question.

Question: Which of the following parameters of the fluid is not very important, while deciding its route in a shell and tube heat exchanger?
[A].

Corrosiveness & fouling characteristics

[B].

pressure

[C].

viscosity

[D].

density

Answer: Option D

Explanation:

No answer description available for this question.

Question: 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.

Answer: Option B

Explanation:

No answer description available for this question.

Question: A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires
[A].

less heating surface.

[B].

more space.

[C].

lower maintenance cost.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Low thermal conductivity of heat insulating materials is due to its
[A].

dense structure.

[B].

high proportion of air space.

[C].

high specific heat.

[D].

none of these.

Answer: Option B

Explanation:

No answer description available for this question.