Chemical Engineering Archives

4421. In a distillation column, bubble caps are located on trays with a pitch of __________ times the outside diameter of the caps.

1.3 to 2

1.6 to 2

2.5

1.5 to 3

✅ The correct answer is option A.

4422. In packed absorption tower, onset of flooding usually occurs at a pressure drop of about __________ mm of water column per metre height of packing.

25-50

50-75

200-250

750-1000

✅ The correct answer is option B.

4423. __________ liquor is best handled in a long tube vertical evaporator.

Foamy

Scaling

Viscous

Salting

✅ The correct answer is option A.

4424. Of the pressure vessels, with same thickness but different diameters, which one withstands higher pressure ?

Larger dia vessel.

Smaller dia vessel.

Larger dia long vessel.

Strength of the vessel is same irrespective of the diameter.

✅ The correct answer is option B.

4425. The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is

∞

minimum

✅ The correct answer is option B.

4426. Generally, elliptical dished heads

are manufactured on 2:1 ratio of major to minor axis and is recommended to be used for pressure vessels operating above a pressure of 1.5 MN/m2 .

resist half the pressure rating compared to hemi spherical head provided on the cylindrical shell of the same thickness and diameter.

are approximately as strong as seamless cylindrical shell having the corresponding I.D and O.D.

all (a), (b) and (c)

✅ The correct answer is option D.

4427. Tube wall thickness depends on the cor-rosiveness 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.

✅ The correct answer is option B.

4428. Maximum plate efficiency is achieved in case of __________ flow.

split

cross

cascade

reverse

✅ The correct answer is option B.

4429. In a distillation column, minimum clearance to be maintained betweeen the overflow weir and the last row of the bubble caps is __________ cms.

2.5

7.5

✅ The correct answer is option B.

4430. Spherical shaped pressure vessel is considered to be the most ideal, because it can

withstand higher pressure for a given metallic shell thickness.

be fabricated very easily.

be designed without wind load considerations.

be supported very easily.

✅ The correct answer is option A.