Pick out the wrong statement pertaining to the rotary dryer ?

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

Related Mcqs:

For continuous drying of granular or crystalline material, the dryer used is the _______________ dryer?
A. Tunnel
B. Tray
C. Rotary
D. None of these
Dryer widely used in a textile industry is ______________ dryer?
A. Festoon
B. Cylinder
C. Conveyor
D. Tunnel
Pick out the wrong statement pertaining to the cooling towers ?
A. In case of induced draft cooling tower, the fan is placed at the top of the tower
B. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and
hot discharged air
C. A natural draft cooling tower is recommended to be used, when the air humidity is low and air
temperature is also low
D. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb
temperature
Pick out the wrong statement pertaining to the analogy between equations of heat and mass_________________?
transfer operations.
A. Sherwood number in mass transfer is analogous to Nusselt number in heat transfer
B. Prandtl number in heat transfer is analogous to Schmidt number in mass transfer
C. Reynolds number in mass transfer is analogous to Grashoff number in heat transfer
D. Reynolds number remains the same in both heat and mass transfer
Pick out the wrong statement pertaining to the cooling towers ?
A. In case of induced draft cooling tower, the fan is placed at the top of the tower
B. Effectiveness of forced draft cooling tower is reduced by the recirculation of the humid and
hot discharged air
C. A natural draft cooling tower is recommended to be used, when the air humidity is low and air
temperature is also low
D. Effectiveness of a mechanical draft cooling tower is reduced with increase in air wet-bulb
temperature
Pick out the wrong statement pertaining to leaching ?
A. Fine solids cannot be leached in a Pachuca tank
B. Door classifier can be used for leaching of coarse solids
C. Vegetable seeds can be leached in either of Bollman extractor, Rotocel or Kennedy extractor
D. Very high temperature is not needed for the leaching of sugar beet
Flights in a rotary dryer are provided to________________?
A. Lift and shower the solids thus exposing it thoroughly to the drying action of the gas
B. Reduce the residence time of solid
C. Increase the residence time of the solid
D. None of these
Capacity of a rotary dryer depends on its __________________?
A. rpm
B. Inclination with ground surface
C. Both A. and B.
D. Neither A. nor B.
Pick out the wrong statement ?
A. Mechanical agitation is required, if the system has low interfacial tension
B. Sieve tray towers are generally used for systems having low interfacial tension
C. When Henry’s law constant is very small, then the mass transfer rate is controlled by the gas
film resistance
D. Taylor-Prandtl analogy for heat and mass transfer considers the transfer through both laminar
and turbulent layers
Pick out the wrong statement?
A. Mass transfer co-efficient does not account for gas-liquid diffusion
B. Diffusion co-efficient and mass transfer co-efficient are not same in any mass transfer
operation
C. Contacting cold vapor-gas mixture with hot liquid exemplifies humidification process
D. Contacting cold liquid with warm vapor-gas mixture exemplifies dehumidification process