The retention time of material in a rotary dryer depends upon its ______________________?

Related Mcqs:

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

   A. Z.H.ρ/L
   B. L/Z.H.ρ
   C. H.ρ/L
   D. Z.H/ρL

2. Hold up of material in a operating rotary drier is in the range of___________________?

   A. 0.05 to 0.15
   B. 0.25 to 0.50
   C. 0.5 to 0.8
   D. 0.8 to 0.9

3. Normally, the length to diameter ratio of rotary dryers varies from 4 to 10 and for its economic operation; the number of transfer units (NTU) for such dryers varies from ?

   A. 1.5-2.5
   B. 3.5-5.5
   C. 7.5-10.0
   D. 10-15

4. Power required for agitation depends upon the______________________?

   A. Height & properties of the liquid
   B. Agitator type & speed of agitation
   C. Size of agitator & the tank
   D. All A., B. and C.

5. Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the_______________?

   A. Flow rates of each fluid
   B. Type and size of packing
   C. Concentration of each fluid
   D. All A, B. & C.

6. The value of fouling factor depends upon the__________________?

   A. Characteristic of process fluid
   B. Velocity of process fluid containing suspended solids
   C. Suspended solids in the fluid
   D. All A., B. and C.

7. The force due to wind load acting on a tall vessel depends upon its___________________?

   A. Shape
   B. Outside diameter
   C. Height
   D. All A, B. & C.

8. Cylindrical shell thickness of rotary drier is generally _______________ mm?

   A. 2-3
   B. 18-22
   C. 6-8
   D. 12-15

9. Height of the flights in the rotary drier is in the range of___________________?

   A. 0.08 to 0.12 d
   B. 0.02 to 0.05 d
   C. 0.2 to 0.5 d
   D. 0.5 to 0.6 d

10. Pressure differential maintained across a continuous rotary vacuum filter is in the range of _______________ mm Hg column?

    A. 50 to 100
    B. 100 to 150
    C. 250 to 500
    D. 600 to 700