chemical engineering process equipment and plant design Mcqs
201. Which of the following is the most common type of baffle used in industrial shell and tube heat exchanger ?
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A. Orifice baffle

B. Disk and doughnut baffle

C. 75% cut segmental baffle

D. 25% cut segmental baffle
202. Spherical shaped pressure vessel is considered to be the most ideal, because it can___________________?
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A. Be fabricated very easily

B. Be designed without wind load considerations

C. Be supported very easily

D. Withstand higher pressure for a given metallic shell thickness
203. Cylindrical pressure vessels in horizontal condition is generally supported on a ________________ support?
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A. Guy wire

B. Saddle

C. Lug

D. Skirt

204. Pick out the wrong statement about the design of sieve plate column and the bubble cap column ?
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A. Weir length for a bubble cap plate is the same as that for the sieve plate

B. Weir height in case of a bubble cap plate ranges from 50 to 150 mm and is higher than the

C. The downcomer design and the residence time in the downcomer is almost same for sieve

D. ve plate

E. te and bubble cap columns

F. Weir height for a bubble cap plate column is the same as that for a sieve plate column
205. Fouling factor must be included in the calculation of overall design heat transfer coefficient, when the liquid__________________?
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A. Is highly viscous

B. Containing suspended solids flows at low velocity

C. Containing suspended solids flows at high velocity

D. Is of high specific gravity

206. Any shell opening greater than 5 cms for a storage tank must be reinforced for reason of ____________________?
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A. Making the joint leak proof

B. None of these

C. Reduction of discontinuity in shape at the junction

D. Preventing the local overstressing of the shell around the opening
207. Corrosion allowance in the design of pressure vessel/chemical equipment is not necessary, if___________________?
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A. Plain carbon steel and cast iron parts are used

B. Wall thickness is > 30 mm

C. Material of construction is high alloy steel

D. Both B. & C.
208. In a _____________ riveted joint, the number of rivets decreases from the innermost row to the outermost row?
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A. Chain

B. None of these

C. Diamond

D. Zig-zag

209. Baffle width is normally taken as ______________ times the tank diameter?
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A. 0.1-0.12

B. 0.4-0.5

C. 0.2-0.45

D. 0.45-0.6

210. _____________ shaped roof is the most commonly used roof for cylindrical storage tanks?
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A. Umbrella

B. Conical

C. Dome

D. Flat

211. Holes of a sieve tray are arranged in triangular pitch of _________________ times the hole diameter?
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A. 1.5 to 2

B. 5 to 10

C. 10 to 15

D. 2.5 to 5
212. In the design of a shell and tube heat exchanger, the corrosion allowance ____________________?
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A. Need not be provided for non-pressure parts like tie rods, spacers, baffles, supports etc.

B. For carbon steel and cast iron pressure parts is 1.5 mm (except for tubes) and for severe

C. ditions it is 3 mm

D. For internal cover and tube sheet is provided on both the sides

E. All A., B. & C.
213. Theoretically calculated diameter of the stripping section of the continuous rectification column is ______________ that of the enriching section?
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A. Less than

B. Either more or less (depending upon relative volatility

C. More than

D. Same as

214. Nominal size of a pipe is an indication of its _______________ diameter?
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A. Approximate

B. Outer

C. Inner

D. None of these

215. Movement of pipeline caused by thermal expansion is taken care by providing ___________________?
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A. Changes in its direction

B. Expansion joint

C. All A., B. and C.

D. Change in the shape of pipeline

216. Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about _____________ kcal/hr.m2.C?
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A. 7500

B. 1250

C. 15000

D. 2500

217. Diameter of bubble caps used in high pressure columns is ______________ as compared to that used in identical vacuum columns?
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A. Less

B. More

C. Same

D. Either A. or B.; no generalisation can be made

218. The ideal size of round bubble caps to be used in industrial distillation column having a diameter of 3-6 metres is ________________ cms?
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A. 7.5

B. 50

C. 15

D. 5

219. Overall distillation column efficiency for most of the refinery columns can be given by (for ? = 0.07 1.4 cp and relative volatility < 4) (where ? = overall column efficiency, % ? = molal average viscosity of feed at average column temperature and pressure, cp ?p = pressure drop per tray, psi) ?
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A. ? = 0.25 log ? 1.67

B. ? = 24.6 (?p/?)

C. ? = 17 61.1 log ?

D. ? = 1.66 0.25 log ?

220. 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_______________?
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A. (ph dh)/ph

B. (ph dh)/dh

C. (ph dh . dt/2)/ph

D. (ph dt)/ph
221. For identical situation, condensing film coefficient in case of a horizontal condenser is almost ______________ the value expected in case of vertical condenser?
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A. Thrice

B. Half

C. Five times

D. Twice

222. A binary liquid Azeotropic mixture has boiling point lower than either of the components, when it shows _____________ deviation from Raoults Law?
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A. No

B. None of these

C. Negative

D. Positive
223. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?
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A. Are easier to clean

B. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less

C. Are less prone to fouling

D. None of these

224. The circumferential (hoop) stress in a thin walled cylindrical vessel under internal pressure is______________________?
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A. pd/t

B. pd/2t

C. pd/4t

D. pd/3t

225. Needle valves are generally not used for___________________?
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A. Smaller sizes of pipe

B. High pressure throttling service

C. Very accurate flow control

D. Very large diameter pipes
226. Which of the following material is seldom used for pressure vessel construction ?
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A. Rimmed still

B. Mild steel

C. Semi-killed steel

D. Killed steel

227. An increase in the liquid resistance to interphase mass transfer and a resultant reduction in plate efficiency is caused by______________?
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A. Decrease in gas solubility for absorbers

B. An increase in relative volatility for rectification columns

C. All A., B. and C.

D. An increase in liquid viscosity

228. In a ______________ riveted joint, the rivets in the various rows are opposite to each other?
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A. Chain

B. Zig-zag

C. Diamond

D. None of these

229. A rupture disc is provided in chemical equipments as an accessory meant for ___________________?
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A. Avoiding vortex formation

B. Enhancing mixing rate

C. Relieving excess pressure

D. Creating turbulence

230. In packed towers provided with saddle packing, liquid redistributors are positioned at every _______________ times column diameter or 6 metres whichever is less?
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A. 15-Oct

B. 3-Feb

C. 20-25

D. 5-8
231. In a rotary drier, the average retention time of solid is (where Z = length of the drier, metres ? = apparent solid density, kg/m3 L = flow rate of dry solids, kg/see. m2 drier crosssection H = hold up of solid.) ?
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A. Z.H.?/L

B. L/Z.H.?

C. H.?/L

D. Z.H/?L

232. The centre to centre distance between two consecutive baffles in a shell and tube heat exchanger is called the baffle pitch or baffle spacing, which is more than 1/5th the I.D. of the shell. Which of the following is not a function of the baffles ?
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A. To increase the tube side heat transfer co-efficient by inducing turbulence

B. To reduce the induced vibration in the tubes

C. To increase the residence time of shell side fluid

D. To provide support to the tube bundle

233. Minimum baffle spacing recommended in a shell and tube heat exchanger is equal to _____________________?
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A. I.D. of the shell

B. 40% of the I.D. of the shell

C. 25 cms

D. 5 cms
234. Equivalent diameter for heat transfer calculation for a duct of square cross-section having each side as d will be__________________?
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A. ?d

B. ?(2d)

C. ?(2?d)

D. d
235. Hold up of material in a operating rotary drier is in the range of___________________?
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A. 0.25 to 0.50

B. 0.8 to 0.9

C. 0.05 to 0.15

D. 0.5 to 0.8

236. Pick out the wrong statement ?
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A. Flat head covers are most suitable for larger vessels operating at very high pressure

B. Flanged only head is a type of flat head in which gradual change in the shape at the centre results in reduced local stresses

C. In a flanged and shallow dished head, the crown radius is > shell outside diameter

D. In a flanged and standard dished head, the crown radius is ? shell outside diameter

237. Commercial packed scrubbers are normally designed for a pressure drop range of ______________ mm water column per metre of packed height?
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A. 8-Apr

B. 52-68

C. 88-105

D. 17-34
238. Cooling water fouling factors vary in the range of 0.001 to 0.003____________________?
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A. (kcal/hr. m. C)-1

B. (W/m2.K)-1

C. (BTU/hr.ft2. F)-1

D. (kcal/hr.m2.C)-1

239. The optimum size ratio for two mixed reactors in series depends on the kinetics of the reaction and the conversion level. For reaction orders more than one, the_________________?
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A. None of these

B. Smaller reactor should come first

C. Equal sized reactors are the best

D. Larger reactor should come first

240. What is the minimum recommended ligament for square pitch arrangement in case of heat exchangers ?
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A. 6.5 cms

B. Equal to tube O.D

C. 6.5 mm

D. Equal to tube I.D

241. Shortest distance between two tubes is___________________?
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A. Called tube clearance

B. Called tube pitch

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

D. None of these

242. In the design of a bag filter, the gas temperature is an important consideration, as it affects the___________________?
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A. Fibre selection

B. Gas density

C. All A., B. & C.

D. Gas viscosity

243. Pressure drop due to pipe fittings can be estimated by the equation, ?P/? = 4f, (Le/D) (V2/2gc) where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of (Le/D) (dimensionless) for 45 elbow and 180 close return bends would be respectively around______________________?
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A. 180 and 300

B. 45 and 75

C. 300 and 500

D. 5 and 10

244. Rivets are generally specified by the____________________?
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A. Shank diameter

B. None of these

C. Overall length

D. Head diameter

245. Saddle supports are used for supporting _____________ vessels?
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A. Horizontal cylindrical

B. Tall vertical

C. Thick walled vertical

D. Thick spherical

246. Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or ______________ times the column diameter, whichever is lower?
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A. 15-20

B. 10-12.5

C. 5-7.5

D. 2.5-3.0
247. Which of the following factors determine the amount of entrainment in a distillation column ?
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A. Plate spacing

B. Depth of liquid above the bubble cap slots

C. All A., B. and C.

D. Vapour velocity in the volume between the plates

248. The type of stress developed in a metallic bar on subjecting it to a change in temperature without allowing it to be deformed is ______________ stress?
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A. Shear

B. Thermal

C. Compressive

D. Tensile

249. The distance between the top of the slots and the liquid surface when the static liquid is just ready to flow over the overflow weir is called____________________?
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A. Downcomer liquid seal

B. Static submergence

C. Skirt clearance

D. None of these

250. A forced circulation long tube vertical evaporator as compared to the natural circulation evaporator__________________?
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A. Is economical in operation

B. Employs high velocity, high heat transfer rate and less heating surface requirement

C. Employs a centrifugal pump placed between external downtake from vapor drum and inlet to

D. e bundle

E. Both B. & C.