With increase in drum speed, in a rotary drum filter, the filtration rate_______________?

Related Mcqs:

1. The basic filtration equation is given as dt/dV = (μ/A ΔP). [(α .CV/A) + Rm], where, V is volume of the filtrate; A is the filtration area, a is specific cake resistance, μ is viscosity of the filtrate, and C is the concentration of the solids in the feed slurry. In a 20 minutes constant rate filtration, 5 m3 of filtrate was obtained. If this is followed by a constant pressure filtration, how much more time in minutes, it will take for another 5 m3 of filtrate to be produced? Neglect filter medium resistance, Rm; assume incompressible cake ?

   A. 10
   B. 20
   C. 25
   D. 30

2. Percentage of drum submerged in the slurry in case of rotary drum filter is ________________?

   A. 3
   B. 30
   C. 85
   D. 25

3. Filtration capacity of a rotary drum vacuum filter depends upon the_______________?

   A. Cake thickness
   B. Characteristics of the feed slurry
   C. Both A. & B.
   D. Neither A. nor B.

4. Filter aids like asbestos, kieselguhr, diatomaceous earth etc. are used to increase the porosity of the final filter cake & reducing the cake resistance during filtration. Filter aid is_______________?

   A. Added to the feed slurry
   B. Pre-coated on the filter medium prior to filtration
   C. Separated from the cake by dissolving solids or by burning it off
   D. All A, B. & C.

5. Filtrate flow rate in case of a rotary drum vacuum filter (in which Rm < < Rc) is proportional to ____________ and the cycle time (where, μ = filtrate viscosity Rm = filter medium resistance Rc = cake resistance)?

   A. √μ
   B. 1/√μ
   C. 1/μ
   D. 1/μ2

6. The speed of a rotary drum vacuum filter may be about _____________ rpm?

   A. 1
   B. 50
   C. 100
   D. 500

7. The cake resistance increases steadily with the time of filtration in a plate and frame filter employing constant ______________ filtration?

   A. Rate
   B. Pressure
   C. Both A. & B.
   D. Neither A. nor B.

8. The controlling resistance in a rotary drum vacuum filter is the ________________ resistance?

   A. Piping
   B. Cake
   C. Filter medium
   D. None of these

9. Vacuum is applied in _______________ zone, in case of a general type continuous rotary drum vacuum filter?

   A. Filtering
   B. Washing
   C. Drying
   D. All A., B. & C.

10. A centrifugal filtration unit operating at a rotational speed of w has inner surface of the liquid (density ρL) located at a radial distance R from the axis of rotation. The thickness of the liquid film is δ and no cake is formed. The initial pressure drop during filtration is ___________________?

    A. ½w2 . R2 . ρL
    B. ½w2 . δ2 . ρL
    C. ½w2 . δρL (2R + δ)
    D. ½w2 . R . ρL(R + 2δ)