Concepts ED/PD

• The ratio of shear stress to shear strain is called

  shear modulus
• Which of the following material is seldom used for pressure

  vessel construction?

  Rimmed still
• Fresh water carrying pipelines in chemical industries are

  colored with___color.

  sea green
• 25% cut segmental baffle means that the baffle height is 75% of the I.D. of the shell.
• Liquid/petroleum fuel storage tanks are built underground

  (as in case of petrol pumps), when the storage capacity is

  less than __ kilolitres.

  45
• Le/D for fully open globe value may be around

  300]
• Lug support is

  A.the most suitable for thick vertical vessel.

  B. same as bracket support.

  C.provided usually for vessels of much smaller height than

  skirt supported vessels.

  all
• With increase in the number of shell passes, the value of FT

  increases
• Holes of a sieve tray are arranged in triangular pitch of____times the hole diameter.

  2.5 to 5
• 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.

  5-11
• The stress developed in a material without any permanent set is

  called the

  elastic limit
• In a shell and tube heat exchanger, the 'tube pitch' is defined as

  the shortest centre to centre distance between adjacent

  tubes.
• Which of the following is not a valid assumption in continuous

  binary distillation for calculating the number of equilibrium stages

  by Mc-Cabe-Thiele's method ?

  Reflux is not a saturated liquid.
• The value of fouling factor depends upon the

  A.characteristic of process fluid.

  B. velocity of process fluid containing suspended solids.

  C. suspended solids in the fluid.


  all
• In case of bubble cap distillation column of diameter greater than

  1.2 m, the cap diameter is roughly about __cm.

  10
• Tube side pressure drop in a 1-2 heat exchanger (for turbulent

  flow of fluids through the tubes) is about ___times, that

  in a 1-1 heat exchanger having the same size & number of tubes

  and operated at the same liquid flow rate.

  8
• To keep the power input constant for a stirred vessel operating

  under fully developed turbulent flow conditions (constant power

  number), if the impeller diameter is increased by 20%, the

  impeller speed should be decreased by a factor of

  (1.2)^5/3
• In a heat exchanger, shell side fluid velocity can be changed by

  changing the tube

  A.layout

  B. pitch

  both
• Where does the maximum tensile strength occur in a thick

  cylindrical vessel subjected to internal pressure?

  At the inner surface.
• It is not desirable to design a heat exchanger for LMTD

  correction factor, FT, of less than

  0.80
• Arivetted joint does not fail by __of rivets.

  0.55
• Triangular pitch tube layout as compared to square pitch in a

  shell and tube heat exchanger permits the use of more tubes in a given shell diameter.
• Bracket supports are the most suitable for supporting thick walled vertical vessels.
• In a multi-pass shell and tube heat exchanger, the shell side

  cross flow area does not depend upon

  A.baffle spacing

  B. clearance

  C. pitch

  none
• Two iron pipes of the same nominal diameter but different

  schedule numbers will have the same

  inside diameter
• Lessing ring is formed by the addition of a partition across the

  centre of a raschig ring, which results in an area increase of

  about 20 percent.
• In chemical process equipment, the conical bottom heads used,

  usually has an apex angle of

  60°
• Smaller sized packings are generally dumped to the packed

  columns, and the large ones of size greater than ___

  mm are stacked individually, which provides better control over

  bed porosity and offers lower gas pressure drop.

  75
• Correct use of 'factor of safety' is very important in equipment

  design. It is defined as the ratio of the

  ultimate stress to working stress.
• The operating velocity in the absorption tower is usually 40-50%

  of the flooding velocity. Packed absorption towers are normally

  designed for a pressure drop of about ___mm of water

  column per meter height of packing.

  20-40
• In perforated plate towers, the

  A.hole sizes may be around 1/8" or 3/16".

  B.total hole area may be around 6 to 15% of tower cross-

  sectional area.

  C. pressure drop is less compared is similar bubble cap towers.

  all
• The ends of a cylindrical vessel can be closed by a head, which

  can be one of the four shapes. For the same thickness, choose

  the one which can withstand the highest pressure.

  Ellipsoidal
• Wall thickness of schedule 40 pipe as compared to that of

  schedule 80 pipe is

  less
• Pick out the wrong statement pertaining to the design of a

  basket type evaporator.

  It is used for high viscosity liquor having large rate of scaling.
• Speed of the drum of the rotary vacuum filter normally ranges

  from __rpm.

  0.1 to 2
• A stuffing box is used for

  prevention of fluid leakage around moving parts.
• Shell side heat transfer co-efficient in case of square pitch as compared to the triangular pitch under similar condition of fluid flow and tube size is

  less
•       _ tray arrangement is recommended for distillation column having diameter up to 4 ft.

  cross flow
• What is the value of 'q' for saturated liquid feed to a distillation column ?

  1
• The main purpose of providing stepping on the trays is to

  facilitate handling of large flow rate of liquid