A shell may by termed as thin if its thickness to diameter ratio is less than 0.1. The factor which can be neglected in the calculation of membrane stresses is________________?

Related Mcqs:

1. In case of a shell and tube heat exchanger, the minimum shell thickness for carbon steel (inclusive of corrosion allowance) depends on shell diameter and is in the range of ________________ mm?

   A. 3-5
   B. 5-11
   C. 8-15
   D. 12-18

2. For annular flow of a fluid, the ratio of the equivalent diameter for pressure drop calculation to the equivalent diameter for heat transfer calculation is_________________?

   A. d1/(d1 + d2)
   B. d2/(d1 + d2)
   C. (d1 + d2)/d1
   D. (d1 + d2)/d2

3. In case of a ‘thin’ pressure vessel, the ratio of its diameter to wall thickness is_________________?

   A. < 10
   B. > 10
   C. > 20
   D. 30

4. Ratio of tube length to shell diameter for a shell and tube heat exchanger is________________?

   A. 8 : 1 to 12 : 1 for both liquid-liquid and gas-gas heat exchangers
   B. 4 : 1 to 8 : 1 for liquid-liquid exchanger
   C. < 4 : 1 for gas-gas exchangers
   D. Both B. & C.

5. A pressure vessel is said to be made of ‘thick’ shell, if the ratio of its diameter to wall thickness is_______________?

   A. < 10
   B. > 10
   C. > 20
   D. < 20

6. In a shell and tube heat exchanger having square pitch, the shell side equivalent diameter is given by (where, P = pitch, d = outside diameter of the tube) ?

   A. 4(P2 – πd2/4)/πd
   B. (P2 – rd2/4)/rd
   C. 4P2/πd
   D. πd/4P2

7. The wall thickness of thin cylindrical shell with hemispherical ends is ______________ that of the spherical ends?

   A. Equal to
   B. More than
   C. Less than
   D. Either B. or C.; depends on maximum permissible internal pressure

8. 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

9. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

   A. Are easier to clean
   B. Are less prone to fouling
   C. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
   D. None of these

10. Tube wall thickness depends on the corrosiveness of the fluids and their operating pressure & temperature and is specified by Birmingham wire gauge (B.W.G)-a number which varies from 8 to 18 with the numbers 14 and 16 being more commonly used. Outside diameter of tubes varies from about 15 to 50 mm; however a tube of less than _____________ mm outside diameter is generally not recommended for fouling fluids ?

    A. 16
    B. 19
    C. 28
    D. 38