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. The specific cake resistance for compressible sludges is a function of the pressure drop__________________?

   A. Over cake
   B. Over medium
   C. Overall
   D. None of these

3. With increase in the pressure drop across the cake, the specific cake resistance for the compressible sludge________________?

   A. Increases
   B. Decreases
   C. Remains constant
   D. Increases linearly

4. Filtration rate through a filter cake is proportional to (where, S = filtering surface R = specific cake resistance μ = viscosity of the filtrate) ?

   A. S
   B. 1/R
   C. 1/μ
   D. All A., B. & C.

5. 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.

6. 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

7. 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)

8. The unit of specific cake resistance is______________________?

   A. gm/cm2
   B. cm/gm
   C. cm/gm2
   D. gm/gm

9. Cake resistance is___________________?

   A. Important in the beginning of filtration
   B. Decreased with the time of filtration
   C. Independent of pressure drop
   D. None of these

10. 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.