Free Plant Design and Economics MCQs with Answers

• A. Avoiding vortex formation
• B. Creating turbulence
• C. Enhancing mixing rate
• D. Relieving excess pressure

Explanation: A rupture disc is a thin, non-reclosing pressure-relief device that bursts at a specified pressure to protect equipment from overpressure.

• A. ζ/E
• B. ζ
• C. E
• D. E/ζ

Explanation: In the elastic range, strain equals stress divided by Young’s modulus, so the yield strain is ζ/E.

• A. Ultimate tensile strength (or yield point) of the material and operating temperature
• B. Operating pressure and welding/joint efficiency
• C. Diameter of the vessel
• D. All A., B. and C.

Explanation: Vessel thickness is set by the pressure-induced stress, vessel diameter, allowable material strength at operating temperature, and joint…

• A. Tall (say 30 metres), but is full of liquid
• B. Tall but empty
• C. None of these
• D. Short (< 2 m) and housed indoor

Explanation: A short vessel housed indoors is largely shielded from wind and has little exposed area, so wind loading may commonly be neglected.

• A. Ultimate
• B. Breaking
• C. Yield point
• D. None of these

Explanation: The largest load carried during the test divided by the specimen’s original cross-sectional area is the ultimate stress.

• A. 25
• B. 23
• C. 26
• D. 27

Explanation: The rivet hole is made slightly larger than the rivet shank to allow insertion and subsequent expansion during riveting.

• A. Working
• B. Allowable
• C. Damaging
• D. None of these

Explanation: The factor of safety compares the stress that would damage or fail the member with the lower stress permitted in design or service.

• A. Saddle
• B. Socket
• C. Nipple
• D. Ferrule

Explanation: A ferrule is a removable sleeve or fitting used to connect a tube to a tube sheet, allowing the tube connection to be serviced or…

• A. pd/2t
• B. pd/4t
• C. pd/t
• D. pd/8t

Explanation: For a thin cylindrical vessel, the longitudinal stress is obtained by balancing pressure force on a longitudinal section with the wall…

• A. Geometrical
• B. Kinematic
• C. All A., B. and C.
• D. Dynamic

Explanation: Similarity-based scale-up requires geometric similarity for shape, kinematic similarity for motion, and dynamic similarity for the ratios…

• A. 0.5
• B. 1.5
• C. 2.5
• D. 3.5

Explanation: Hydrostatic tests are commonly conducted at about 1.5 times the internal design pressure, providing a safety margin for leakage and…

• A. 16
• B. 19
• C. 28
• D. 38

Explanation: Tubes smaller than about 19 mm outside diameter are generally avoided for fouling fluids because deposits rapidly restrict their flow area…

• A. 1.2
• B. 0.5
• C. 3.8
• D. 6.8

Explanation: For plain carbon-steel shells, butt-welded construction is used for plate thicknesses up to about 3.8 cm, or 38 mm.

• A. Clearance between shell & baffles and between tube & baffles should be minimum to avoid
• B. by-passing of the fluid, but it should be enough to permit the removal of tube bundle
• 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. number of tie rods is 4 with at least 10 mm diameter
• F. Tie rods are fixed at one end in the tube sheet by making blind holes and the minimum

Explanation: Horizontal shell-and-tube exchangers are normally supported on saddle supports, while vertical units use brackets, lugs, or skirt-type…

• A. Equal to the impeller diameter
• B. Twice the tank diameter
• C. Twice the impeller diameter
• D. 3/4 of the tank height

Explanation: A baffle must extend sufficiently through the mixing zone to suppress swirling and promote radial mixing; a commonly used minimum is about…

• A. Remains same throughout
• B. Increases upwards
• C. Decreases upwards
• D. May decrease or increase upwards depending upon whether vacuum or positive pressure
• E. would be maintained inside the shell

Explanation: The lower shell courses carry greater hydrostatic liquid pressure, so they require greater thickness.

• A. Hemispherical
• B. Conical or flat plate
• C. Torispherical
• D. Elliptical

Explanation: A flat plate or conical closure has poorer pressure strength than hemispherical, elliptical, or properly proportioned torispherical heads.

• A. 1 to 5
• B. 30 to 40
• C. 10 to 20
• D. 40 to 50

Explanation: The corrosion-resistant cladding is only a thin protective layer, while most of the vessel thickness provides mechanical strength.

• A. Black
• B. Yellow
• C. Red
• D. White

Explanation: White paint reflects more solar radiation and keeps the tank and its contents cooler, reducing vapour formation and fire risk.

• A. Both A. & B.
• B. Sales demand is fluctuating
• C. Quality & yield cannot be achieved in continuous processes, because of long residence time
• D. Neither A. nor B.

Explanation: Batch operation is advantageous when demand varies because production can be started or stopped without continuously operating a large…