chemical engineering process equipment and plant design Mcqs
1. Frame thickness in the plate and frame filter press is normally in the range of ______________ inches?
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A. 0.25 to 4

B. 1 to 12

C. 0.25 to 8

D. 1 to 5

2. 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?
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A. 30 to 40

B. 1 to 5

C. 10 to 20

D. 40 to 50

3. Scale up problem in design based on the similarity concept takes into account _______________ similarity?
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A. All A., B. and C.

B. Kinematic

C. Dynamic

D. Geometrical

4. High pressure fluid in a shell and tube heat exchanger should preferably be routed through the________________?
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A. Shell side for smaller total pressure drop

B. Shell side for large overall heat transfer co-efficient

C. Shell side, if the flow is counter-current and tube side if the flow is co-current

D. Tubes to avoid the expansion of high pressure shell construction
5. The LMTD correction factor (FT) is defined as the __________________?
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A. Ratio of LMTD to the true temperature difference

B. Ratio of true temperature difference to the LMTD

C. Geometric mean of the true temperature difference and the LMTD

D. Differenced of true temperature difference and the LMTD

6. In case of a thin pressure vessel, the ratio of its diameter to wall thickness is_________________?
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A. < 10

B. > 10

C. 30

D. > 20

7. In the allocated cap area, bubble caps are generally arranged on equilateral triangular pitch. Number of caps fixed on a plate is with a __________________?
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A. Neither A. nor B.

B. Either A. or B.

C. Cap pitch of 1.3-2 times the cap diameter

D. Clearance of 25-75 mm

8. At the following point for a given packing and set of fluids, the pressure drop per metre of packed height, with variation in fluid rates and operating pressure____________________?
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A. May increase or decrease depending upon the solubility of the gas in the liquid

B. Decreases

C. Remain same

D. Increases

9. Value of Peclet number = 0, is the representative of ____________________?
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A. Plug flow

B. Complete back mixing

C. Eddy diffusivity = 0

D. Laminar flow

10. The minimum baffle height should be ______________?
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A. Twice the impeller diameter

B. 3/4 of the tank height

C. Twice the tank diameter

D. Equal to the impeller diameter

11. In distillation columns, bubble caps are held in place over trays by ________________?
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A. Rivets

B. A hold down bar

C. Bolts

D. Both B. and C.
12. The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the _______________ stress?
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A. Allowable

B. None of these

C. Working

D. Damaging
13. Steam economy is defined as the amount of evaporation per unit amount of steam used, while the capacity is the total evaporation obtained per hour. Use of multiple effects in evaporation ?
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A. Increases capacity

B. Increases economy

C. Does not affect the capacity

D. Both B. & C.
14. For a cylindrical shell, (subject to the thickness of uppermost course being more than the minimum for dia of the tank in question), the thickness of the courses of shell_________________?
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A. ld be maintained inside the shell

B. May decrease or increase upwards depending upon whether vacuum or positive pressure

C. Decreases upwards

D. Remains same throughout

E. Increases upwards

15. In a shell and tube heat exchanger, the shortest centre to centre distance between the adjacent tubes is__________________?
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A. Called tube pitch

B. Always less than the diameter of the tube

C. Called tube clearance

D. None of these

16. Power required for agitation depends upon the______________________?
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A. Agitator type & speed of agitation

B. Height & properties of the liquid

C. Size of agitator & the tank

D. All A., B. and C.
17. What is the value of q for saturated vapor feed to a distillation column? (where q = fraction of the feed stream that is liquid ?
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A. 1

B. 0

C. 1

18. In case of plain carbon steel, butt welded joints are used for shell plate thickness ? _____________ cms?
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A. 3.8

B. 1.2

C. 0.5

D. 6.8

19. In a pressure vessel containing multiple openings of various dimensions at different parts, stress concentration at the edges of the opening is maximum which becomes negligibly small beyond the area covered by ______________ times the hole diameter?
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A. Ten

B. Two

C. Five

D. Twenty

20. The ratio of the largest load in a test to the original cross-sectional area of the test specimen is called the _____________ stress?
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A. None of these

B. Ultimate

C. Yield point

D. Breaking

21. Baffle spacing is generally _________________ the I.D. of the shell ?
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A. More than

B. Not greater than

C. Not less than one fifth of

D. Both B. and C.
22. Heat transfer co-efficient for a horizontal condenser as compared to a vertical condenser operating under similar conditions is_______________?
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A. Less

B. About 0.33 times

C. Same

D. About 3 times
23. If D is the inside diameter of the shell of a shell and tube heat exchanger, then the baffle spacing is usually in the range of__________________?
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A. None of these

B. D/5 or minimum 2? to D

C. D/5 or minimum 2? to 5D

D. D/2 or minimum 2? to 5D

24. ___________ tower is the most suitable gas-liquid contacting device involving highly corrosive fluids?
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A. None of these

B. Bubble cap plate

C. Packed

D. Sieve plate

25. The dust collection efficiency of a cyclone separator_________________?
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A. None of these

B. Decreases with increase in gas flow rate

C. Is inversely proportional to the mass of the dust particle

D. Is directly proportional to the radius of the dust particle path

26. 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 ?
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A. 28

B. 19

C. 16

D. 38

27. Bubble cap tray is the most commonly used tray in large distillation column, because______________?
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A. It incurs less pressure drop as compared to any other try designed for the same duty

B. It eliminates the foaming and entrainment tendency during operation

C. None of these

D. Of its flexibility and nearly constant efficiency under varying conditions of operation
28. 1.2 to 3.8 cms is the value of the ______________________?
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A. All A., B. and C.

B. Skirt clearance for bubble caps

C. Downcomer liquid seal in case of a balanced tray design

D. Static submergence in case of a bubble cap tray for column operating under pressure (? 1 atm)

29. Low pressure steam (with saturation temperature between 105 to 120C) is usually used in the vacuum evaporators, which normally employ a vacuum of about _______________ mm Hg (referred to a 760 mm mercury barometer)?
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A. 450

B. 750

C. 250

D. 650
30. Pick out the wrong statement?
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A. The discharge end of the downcomer must project far enough into the tray liquid so that no

B. If sufficient residence time (around 8 seconds) is not provided to the downcoming liquid in

C. None of these

D. The liquid head in the downcomer should not be greater than one half the plate spacing to

E. downcomer, it may entrain some vapour

F. id flooding

31. For identical operating conditions, the pressure drop over _______________ tray is the highest out of the following?
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A. Valve

B. Sieve

C. Counter flow

D. Bubble cap
32. The length of straight rectangular weir used on cross-flow trays is generally ________________ the column diameter ?
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A. 2 ft irrespective of (for column > 3 ft diameter)

B. Twice

C. Equal to

D. 0.6-0.8 times
33. For a 25 mm hole drilled in plates to be riveted, the shank diameter of the rivet should be _______________ mm?
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A. 23

B. 25

C. 26

D. 27

34. In a shell and tube heat exchanger, the clearance of the tube is generally___________________?
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A. Not less than one-fourth of the tube diameter or 3/16?

B. More than the tube diameter

C. Equal to the tube diameter

D. More in case of triangular pitch as compared to the square pitch tube layout

35. (Le/D) for a Tee (used as elbow, entering run) would be around _______________________?
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A. 5

B. 160

C. 60

D. 200

36. Baffles are provided in a shell and tube heat exchanger to increase the turbulence and velocity of the shell side fluid. Which of the following shaped baffles does not fall in the category of transverse baffle ?
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A. Flat plate extending across the wall

B. Segmental baffle

C. Disk type baffle

D. Helical type baffle

37. Cylindrical shell thickness of rotary drier is generally _______________ mm?
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A. 15-Dec

B. 6-8

C. 3-Feb

D. 18-22

38. 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) ?
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A. (P2 rd2/4)/rd

B. 4P2/?d

C. ?d/4P2

D. 4(P2 ?d2/4)/?d
39. Which of the following is the best tube material from thermal conductivity point of view alone ?
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A. Copper

B. Carbon steel

C. Aluminium

D. Stainless steel

40. Pick out the wrong statement pertaining to shell and tube heat exchanger_______________?
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A. Tie rods are fixed at one end in the tube sheet by making blind holes and the minimum

B. Clearance between shell & baffles and between tube & baffles should be minimum to avoid

C. Baffles are supported independently of the tubes by tie rods and positioned by spacers

D. Bracket supports are used for horizontal shell, while saddle support is used for vertical shell

E. ber of tie rods is 4 with at least 10 mm diameter

F. passing of the fluid, but it should be enough to permit the removal of tube bundle

41. The longitudinal stress induced in a thin walled cylindrical vessel under internal pressure is_________________?
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A. pd/2t

B. pd/t

C. pd/4t

D. pd/8t

42. Pick out the wrong statement pertaining to the design of a horizontal tube evaporator ?
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A. Its usual dimensions are: tube dia = 2-3 cms; evaporator body dia = 1-4 metres and evaporator

B. Liquor flows inside the tube, while the steam is outside submerging the tube

C. It is suitable for process, in which the final product is a liquor instead of solid

D. ght = 2.5-4 metres

E. It is unsuitable for concentrating those liquids, which form a scale or deposit salt

43. ______________ closure is the weakest enclosure for cylindrical vessels?
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A. Elliptical

B. Hemispherical

C. Torispherical

D. Conical or flat plate
44. Removable connection of tubes to tube sheet is called___________________?
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A. Socket

B. Saddle

C. Ferrule

D. Nipple

45. In a distillation column, bubble caps are located on trays with a pitch of ______________ times the outside diameter of the caps?
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A. 2.5

B. 1.6 to 2

C. 1.5 to 3

D. 1.3 to 2
46. Wind load consideration in the design of a support can be neglected, when the vessel is___________________?
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A. Tall but empty

B. Tall (say 30 metres), but is full of liquid

C. Short (< 2 m) and housed indoor

D. None of these

47. The necessary wall thickness for a metallic storage vessel is a function of the ___________________?
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A. Diameter of the vessel

B. All A., B. and C.

C. Ultimate tensile strength (or yield point) of the material and operating temperature

D. Operating pressure and welding/joint efficiency

48. In a double pipe (concentric) heat exchanger, the hydraulic radius for heat transfer (for a fluid flowing through the annulus) would be_________________?
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A. Less than that for fluid flow

B. Same as that for fluid flow

C. More than that for fluid flow

D. D2 D1 (D1 and D2 are I.D. of inner and outer pipes respectively)

49. In case of saddle packing (e.g., berl and intralox saddles), the maximum size of the packing should not exceed ______________ of the column diameter?
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A. 1/5th

B. 1/50th

C. 1/30th

D. 1/15th
50. At equal mass velocities, the values of film co-efficients for gases as compared to that for liquids are generally ?
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A. Lower

B. Higher

C. Unpredictable

D. Same