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Chemical Engineering :: Mechanical Operations

  1. __________ conveyor is the most suitable for long distance transportation of cold, non-abrasive granular/irregular shape/fine materials.

  2. A.
    Bucket
    B.
    Belt
    C.
    Screw
    D.
    Apron

  3. The specific cake resistance for compressible sludges is a function of the pressure drop

  4. A.
    over cake
    B.
    over medium
    C.
    overall
    D.
    none of these

  5. Moisture can be removed from lubricating oil using

  6. A.
    tubular centrifuge
    B.
    clarifier
    C.
    sparkler filter
    D.
    vacuum leaf filter

  7. Tabling process used for separating two materials of different densities by passing the dilute pulp over a table/deck, which is inclined from the horizontal surface at an angle of about

  8. A.
    1 to 2°
    B.
    2 to 5°
    C.
    5 to 10°
    D.
    10 to 15°

  9. Pick out the wrong statement.

  10. A.
    Gape is the greatest distance between the crushing surfaces or the jaws.
    B.
    The angle of nip (2α) is the angle between roll faces at the level where they will j ust take hold of a particle and draw it in the crushing zone.
    C.
    Crushing efficiency is the ratio of the energy absorbed by the solid to the surfaces energy created by crushing.
    D.
    Reduction ratio is the ratio of the maximum size of the particles in the feed to that in the product.

  11. Addition of filter aid to the slurry before filtration is done to ...... of the cake.

  12. A.
    increase the porosity
    B.
    increase the compressibility co-efficient
    C.
    decrease the porosity
    D.
    decrease the compressibility co-efficient

  13. Which of the following terminology is not used for size reduction of materials to fine sizes or powders?

  14. A.
    Comminution
    B.
    Dispersion
    C.
    Pulverisation
    D.
    Compression

  15. A tube mill as compared to a ball mill

  16. A.
    employs smaller balls.
    B.
    gives finer size reduction but consumes more power.
    C.
    has larger length/diameter ratio (>2 as compared to 1 for ball mill).
    D.
    all (a), (b) and (c).

  17. Kick's law assumes that the energy required for size reduction is proportional to the logarithm of the ratio between the initial and the final diameters. The unit of Kick's constant is

  18. A.
    kW. sec/kg
    B.
    kWh/kg
    C.
    kWh/sec. kg
    D.
    kg/sec.