Process Equipment And Plant Design - Study Mode

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[#176] Normally, the length to diameter ratio of rotary dryers varies form 4 to 10 and for its economic operation, the number of transfer units (NTU) for such dryers varies from

(A) 1.5-2.5

(B) 3.5-5.5

(C) 7.5-10.0

(D) 10-15

Correct Answer

(A) 1.5-2.5

[#177] Factor of safety (i.e., overdesign factor) in heat transfer equipments is about __________ percent more than the actual/theoretical design factor.

(A) 5-10

(B) 15-20

(C) 30-35

(D) 35-40

Correct Answer

(B) 15-20

[#178] Minimum baffle spacing recommended in a shell and tube heat exchanger is equal to

(A) 5 cms

(B) 40% of the I.D. of the shell

(C) 25 cms

(D) I.D. of the shell

Correct Answer

(A) 5 cms

[#179] The ratio of tube length to shell diameter in case of liquid shell and tube heat exchanger ranges from

(A) 2 to 3

(B) 3 to 5

(C) 4 to 8

(D) 6 to 12

Correct Answer

(C) 4 to 8

[#180] Which tube arrangement in a heat exchanger would facilitate highest heat transfer rate?

(A) Triangular pitch

(B) Square pitch

(C) Diagonal square pitch

(D) Heat transfer rate is independent of tube arrangement

Correct Answer

(A) Triangular pitch