Category: Mass Transfer

A. Nature of the vapor
B. Temperature of the mixture
C. Composition of the mixture
D. None of these

A. 2.09 × 10-4
B. 2.09 × 10-5
C. 2.09 × 10-9
D. 2.09 × 10-12

A. At ground level
B. 2 metres above the ground
C. 5 metres above ground
D. 10 metres above ground

A. Less
B. More
C. Same
D. Unpredictable

A. Increases
B. Decreases
C. Remains unchanged
D. Decreases exponentially

A. rpm
B. Inclination with ground surface
C. Both A. and B.
D. Neither A. nor B.

A. Higbie
B. Fick
C. Ergun
D. Levenspiel

A. Continuous
B. Batch
C. Semi-batch
D. Cooling (adiabatic)-cum-evaporation

A. Flights (located in the inside shell of rotary dryer) lift the material being dried and shower it
down through the current of hot air/gases. It extends from the wall to a distance which is about
8-12% of the inside diameter of shell
B. Hold up of a rotary drier is defined as the fraction of the dryer volume occupied by the solid at
any instant. The best performance for rotary drier is obtained, when the hold up is in the range
of 0.05 to 0.15
C. Rotary dryer is suitable for drying sticky material
D. Recommended peripheral speed of a rotary drier is in the range of 10 to 30 metres/minute

A. Increase
B. Decrease
C. Remain same
D. Depend on saturated boiling point; may increase or decrease