The LMTD correction factor (FT) is defined as the ratio of true temperature diff

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Question
The LMTD correction factor (F_T) is defined as the
Options
A. ratio of true temperature difference to the LMTD.
B. ratio of LMTD to the true temperature difference.
C. differenced of true temperature difference and the LMTD.
D. geometric mean of the true temperature difference and the LMTD.

Correct Answer

ratio of true temperature difference to the LMTD.

Process Equipment and Plant Design problems

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1. Large process vessels operating under extreme temperature and pressure conditions are normally clad/ lined with materials like stainless steel, aluminium, nickel & its alloys, copper & its alloys and titanium. The cladding thickness is generally about __________ percent of the total thickness.
Options
A. 1 to 5
B. 10 to 20
C. 30 to 40
D. 40 to 50

2. 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
Options
A. 1.5-2.5
B. 3.5-5.5
C. 7.5-10.0
D. 10-15

3. The wall thickness of thin cylindrical shell with hemispherical ends is __________ that of the spherical ends.
Options
A. equal to
B. more than
C. less than
D. either (b) or (c); depends on maximum permissible internal pressure

6. The clearance between two tubes in a shell and tube heat exchanger is known as 'ligament', whose minimum value is __________ the outside diameter of the tube, but in no case it should be less than 4.5 mm.
Options
A. equal to
B. half
C. one fourth
D. three fourth

7. Stage efficiency for packed tower varies with the
Options
A. type & size of packing.
B. fluid rates and fluid properties.
C. operating pressure and column diameter.
D. all (a), (b) and (c).

10. In a shell and tube heat exchanger, the shortest centre to centre distance between the adjacent tubes is
Options
A. called tube pitch.
B. called tube clearance.
C. always less than the diameter of the tube.
D. none of these.

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