chemical engineering process equipment and plant design Mcqs
301. The operating pressure drop range in a bag filter is about ______________ mm water gauge?
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A. 1500-2500

B. 500-1500

C. 50-150

D. 10-May

302. An under-designed steam trap will___________________?
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A. Destroy itself of acceleration wear due to rapid recycling

B. None of these

C. Waste steam

D. Back up condensate and cause water hammer in steam line
303. Wall thickness of schedule 40 pipe as compared to that of schedule 80 pipe is ___________________?
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A. Same

B. More

C. Less

D. Either A. or B.; depends upon the I.D. of the pipe

304. 25 per cent cut segmental baffle means that the baffle__________________?
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A. Height is 75% of the I.D. of the shell

B. Height is 25% of the I.D. of the shell

C. Spacing is 75% of its height

D. Width is 25% of its height

305. The safe height (h) to diameter D. ratio (i.e., h/d) for liquid/petro fuel storage tank of capacity more than 45 kilolitres is less than _________________?
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A. 3.5

B. 3

C. 1

D. 2

306. _____________ dished head is the strongest of all?
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A. Torispherical

B. Hemispherical

C. Elliptical

D. None of these

307. Lap joints are preferred for plates having thickness _______________ mm?
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A. > 3

B. 10-May

C. < 12.5

D. > 5

308. With increase in pressure drop (for a given particle size), the dust collection efficiency of a cyclone separator will________________?
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A. Remain unaffected

B. Decrease

C. Increase or decrease depending on the nature of the dust

D. Increase
309. 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?
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A. Considerably less than 9

B. Considerably more than 9

C. About 9

D. About 3

310. Vertical vessels are not supported by____________________?
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A. Brackets

B. Skirts

C. Columns

D. Saddles
311. Normally, the length to diameter ratio of rotary dryers varies from 4 to 10 and for its economic operation; the number of transfer units (NTU) for such dryers varies from ?
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A. 7.5-10.0

B. 3.5-5.5

C. 15-Oct

D. 1.5-2.5
312. Pick out the wrong statement pertaining to a shell and tube heat exchanger ?
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A. The maximum value of baffle spacing is equal to the I.D. of the shell

B. Disk and doughnut baffle is the most commonly used baffle

C. The maximum unsupported tube span is generally about 75 times tube diameter, but is reduced to about 60 times for aluminium, copper & alloys of these

D. The minimum value of baffle spacing is 50 mm

313. The ratio for the rate of washing to the final rate of filtration in a washing type of plate and frame filter is____________________?
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A. 0.75

B. 0.25

C. 1.25

D. 0.5

314. Tube height in a calandria type evaporator is normally less than _______________ metres?
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A. 3.5

B. 5.5

C. 2

D. 1

315. Pick out the wrong statement?
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A. A loop seal or U-seal is provided in a vertical condenser sub-cooler to prevent quick draining

B. the condensate

C. Safety valves are provided in heat exchangers for removal of non-condensable

D. Liquid metals and Dowtherm are used for very high temperature heating

E. In a shell and tube heat exchanger, high pressure fluid is generally routed through the tube

316. Mc Cable Thiele method used for finding theoretical stages in a distillation column assumes that the_____________________?
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A. Troutons rule is applicable

B. Liquid/vapor loading across the column remains constant

C. Sensible heat differences are small, because the temperature changes from tray to tray is small

D. All A., B. and C.
317. Pick out the wrong statement. In an agitated vertical cylindrical reaction vessel, the___________________?
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A. Ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1

B. Dished bottom vessel has very high power consumption

C. Filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period

D. Flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids

318. Which of the following efficiencies can be greater than 100% ?
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A. Murphree plate efficiency

B. Point efficiency

C. None of these

D. Overall plate efficiency

319. Maximum acceptable total liquid gradient over a tray is about _______________ mm?
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A. 30.5

B. 45.5

C. 12.5

D. 5.5

320. When one of the fluids is highly corrosive and has fouling tendency, it should_____________________?
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A. Flow at a very slow velocity

B. Preferably flow inside the tube for its easier internal cleaning

C. Flow outside the tube, when the flow is counter-current and inside the tube when the flow is

D. Preferably flow outside the tube

E. current

321. Diameter of the sieve tray column is determined by the_________________?
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A. Height of the plate spacing

B. Hole diameter of the sieve tray

C. Upper limit of the vapour velocity

D. Lower limit of vapour velocity

322. Pick out the wrong statement?
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A. The joint made by overlapping of one plate over the other, and then riveting the two plates together with two rows of rivets is called double riveted butt joint

B. The efficiency of a riveted joint is the ratio of the strength of the riveted joint to the strength of the solid plate

C. Riveting provides a permanent fastening method

D. Shank diameter of the rivets should be less than the size of the hole drilled in the plate for riveting

323. 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?)?
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A. Three fourth

B. Equal to

C. 1.5 times

D. Half

324. In a multiple effect evaporator system having n effects, the amount of water evaporated per unit surface area in approximately equal to _____________ times that in a single effect?
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A. 0.5 nth

B. (1/n)th

C. nth

D. 1.5 nth

325. Pick out the wrong statement ?
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A. A reducer is used to change the direction of a pipe in a straight run

B. A pipe is differentiated from a tube by the fact that a pipe has a greater wall thickness

C. The method of fixing tubes to a tube sheet by expanding is called tube rolling

D. Lug supports are less expensive than other type of supports

E. pared to the tube

326. Liquid gradient over a tray can be minimised by________________?
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A. All A., B. and C.

B. liquid must flow

C. ocity of liquid flow past the caps or by reducing the distance along the tray through which

D. Using split flow, radial flow or cascade flow for column diameter large than 4 ft

E. Providing a higher skirt clearance or a higher weir

F. Decreasing the number of rows of caps through which the liquid flows or by decreasing the

327. Ratio of tube length to shell diameter for a shell and tube heat exchanger is________________?
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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.
328. Pick out the wrong statement pertaining to Horton sphere used for the storage of liquid ammonia ?
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A. Horton sphere is used for the storage of gases and volatile liquid at a moderate pressure of 1 to 10 kg/cm2

B. Diameter of Horton sphere is normally 6 to 25 metres and it is supported by 6 to 12 nos. tubular or rolled section column

C. Horton sphere is used for the storage of liquid at sub-zero temperature at very high pressure upto 200 kg/cm2

D. Thickness of spherical shell is half that of the cylindrical vessel under same operating pressure condition. Besides, the ratio of surface area to volume is less for sphere than any other shape; hence insulation required is less

329. Pick out the wrong statement about distillation operation__________________?
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A. In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation

B. Distillation under vacuum is a substitute for steam distillation

C. Flash distillation, differential distillation & steam distillation are all continuous distillation processes

D. In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other

330. The wall thickness of thin cylindrical shell with hemispherical ends is ______________ that of the spherical ends?
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A. Equal to

B. Less than

C. More than

D. Either B. or C.; depends on maximum permissible internal pressure

331. (Le/D) for couplings and unions would be_______________?
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A. 200

B. Negligible

C. 60

D. 350

332. In a bag filter, the pressure drop increases directly as the___________________?
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A. Density of the gas and inversely as viscosity of the gas

B. Density of the gas, but is independent of the viscosity of the gas

C. None of these

D. Viscosity of the gas and inversely as density of the gas

333. _____________ heat exchanger is also known as hair pin type exchanger?
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A. Finned

B. Plate type

C. Regenerative

D. Double pipe
334. The ratio of lateral strain to linear strain is termed as the___________________?
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A. Bulk modulus

B. Modulus of elasticity

C. Poissons ratio

D. Shear modulus

335. Normal screwed fittings are used for pipes upto a diameter of _______________ inches?
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A. 1.5

B. 9

C. 3

D. 5

336. Minimum tube pitch recommended for shell and tube heat exchangers is about _______________ times the outside diameter of the tube?
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A. 2.5

B. 1.25

C. 3.5

D. 1.75

337. Pick out the wrong statement ?
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A. For all the cylindrical process vessels operating above atmospheric pressure, formed heads are used for closing the vessel

B. Fouling factor of river water is less than that of sea water

C. Risers provided in bubble cap trays in the distillation column facilitate the flow of both liquid and vapor

D. Both B. and C.
338. Souders Brown equation given by, U = Kv ?(?l ?v)/?v, is used for the calculation of the ______________ in a continuous distillation column?
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A. Tray pressure drop

B. Diameter of the bubble cap column

C. Diameter of the sieve plate column

D. Residence time in the downcomer for the disengagement of entrained vapour

339. Pick out the wrong statement?
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A. In a sieve tray, the minimum hole diameter is equal to the tray thickness

B. In practical operation, distillation towers having diameter 3-6 metres equipped with bubble cap (round) size of 15 cms are used

C. In a stainless steel sieve tray, the minimum hole diameter is equal to 10 times the plate thickness

D. Height of packing in a packed tower is about 3 times the column diameter for raschig rings and about 5 to 10 times the column diameter for saddle packing

340. Pick out the correct statement?
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A. Random packing a packed tower offers the advantage of lower pressure drop and higher throughput of fluids as compared to regular/stacked packing

B. Draining of residual liquid on tray during shut down of distillation column is facilitated by weep holes

C. It is preferred to use a vertical condenser for condensation of vapor from a distillation column without sub-cooling

D. Risers are generally not connected to the plate in a distillation coloumn by bolts, rivets or welding
341. Pick out the wrong statement ?
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A. Plate efficiency increases with increase in superficial vapour velocity till entrainment limit

B. Too small a plate spacing can cause a low efficiency, if the vapour velocity is greater than the allowable value

C. Increase in depth of the liquid about the slots increases the plate efficiency, particularly if the liquid depth is < 1"

D. None of these
342. Angled baffles are preferred in the agitation tank to control the swirling action; if the viscosity of the liquid to be mixed is about 200 poise. However, the baffle may be completely eliminated for mixing liquids having viscosity above ____________________ poise?
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A. 1000

B. 600

C. 300

D. 1500

343. Seamless pipe is made________________?
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A. From rolled strips formed into cylinders and seam-welded

B. By extrusion & casting into static and centrifugal molds

C. By forging a solid round, piercing it by simultaneously rotating & forcing it over a piercer

D. nt and further reducing it by rolling gas drawing

E. Both B. and C.
344. Maximum plate efficiency is achieved in case of ______________ flow?
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A. Reverse

B. Split

C. Cross

D. Cascade

345. Le/D) for 90 elbow (medium radius) and 90square elbow would be respectively around___________________?
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A. 3 and 5

B. 100 and 250

C. 25 and 60

D. 250 and 600

346. The average velocity in the tubes of a 1-4 heat exchanger is ______________ times that in 1-1 heat exchanger having the same size & number of tubes and operated at same liquid flow rate ?
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A. 2

B. 2-Jan

C. 4

D. 4-Jan

347. 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________________?
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A. Shear

B. Deformation

C. Bending

D. Elongation

348. What is the slope of the operating line in the rectifying section of a distillation column ?
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A. > 1

B. ?

C.

D. 0

349. The distance between the centres of a rivet hole to the nearest edge of the plate is called _________________?
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A. Pitch

B. Margin

C. None of these

D. Back pitch

350. 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_________________?
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A. d1/(d1 + d2)

B. d2/(d1 + d2)

C. (d1 + d2)/d2

D. (d1 + d2)/d1