Chemical Engineering MCQs

Pick out the wrong statement. In an agitated vertical cylinderical reaction vessel, the

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ratio of liquid depth to tank diameter (i.e. the filling ratio) recommended for most purposes is 1.
filling ratio for dispersing gas in a liquid is 2 for sufficiently long contact period.
flat bottom and conical bottom vessels have low agitation efficiency for agitation of heavy solids in liquids.
dished bottom vessel has very high power consumption.
✅ The correct answer is option D.

Pressure drop due to pipe fittings can be estimated by the equation, , 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 (dimensionless) for 45° elbow and 180° close return bends would be respectively around

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5 and 10
45 and 75
180 and 300
300 and 500
✅ The correct answer is option B.

In a bag filter, the pressure drop increases directly as the

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density of the gas, but is independent of the viscosity of the gas.
density of the gas and inversely as viscosity of the gas.
viscosity of the gas and inversely as density of the gas.
none of these.
✅ The correct answer is option B.

Any shell opening greater than 5 cms for a storage tank must be reinforced for reason of

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preventing the local overstressing of the shell around the opening.
reduction of discontinuity in shape at the junction.
making the joint leak proof.
none of these.
✅ The correct answer is option A.