A perforated plate has holes of diameter dn arranged in a pitch ph. Each hole has a tube of I.D. dt passing through it. The ligament efficiency is given by_______________?

Related Mcqs:

1. In sieve plate column, holes are drilled or punched in sizes ranging from 2.5 to 12 mm (5 mm being widely used). The hole pitch is normally ______________ times the hole diameter to give the required hole area?

   A. 0.5 to 1.5
   B. 2.5 to 4.0
   C. 5 to 10
   D. 10 to 15

2. 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

3. Holes of a sieve tray are arranged in triangular pitch of _________________ times the hole diameter?

   A. 1.5 to 2
   B. 2.5 to 5
   C. 5 to 10
   D. 10 to 15

4. Tubes are fixed to the tube sheet (a thick circular metallic plate) by the method of tube rolling and brazing (non-removable) or ferrule connection (removable). Thickness of the tube, sheet is normally ____________ the outside diameter of the tube but in no case it should be less than 22 mm (7/8″)?

   A. Half
   B. Three fourth
   C. Equal to
   D. 1.5 times

5. In most of the shell and tube heat exchangers, the tube pitch is generally ______________ the tube diameter?

   A. Less than
   B. 1.25-1.50 times
   C. 2.5 times
   D. one-fourth of

6. Minimum tube pitch recommended for shell and tube heat exchangers is about _______________ times the outside diameter of the tube?

   A. 1.25
   B. 1.75
   C. 2.5
   D. 3.5

7. Triangular pitch tube layout as compared to square pitch in a shell and tube heat exchanger________________?

   A. Permits the use of less tubes in a given shell diameter
   B. Facilitates comparatively easier external cleaning because of large clearance
   C. Permits the use of more tubes in a given shell diameter
   D. Both B. and C.

8. For given number of passes, pitch & tube diameter, the maximum number of tubes that can be accommodated in a shell of tripled inside diameter will be ____________ times?

   A. About 9
   B. Considerably more than 9
   C. Considerably less than 9
   D. About 3

9. 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?

   A. Equal to
   B. Half
   C. One fourth
   D. Three fourth

10. A high vapour velocity is required for high plate efficiency in a sieve plate column. The satisfactory value of operating vapor velocity for design purpose in sieve plate column is about _______________ percent of the flooding velocity?

    A. 45
    B. 60
    C. 80
    D. 95