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 ?

Related Mcqs:

1. 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

2. 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.

3. 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.

4. 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.

5. A straight line is obtained on plotting reciprocal of filtration rate vs. the volume of filtrate for _______________ flow of filtrate?

   A. Compressible cakes and laminar
   B. Incompressible cake and laminar
   C. Compressible cake and turbulent
   D. Incompressible cake and turbulent

6. 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)

7. In continuous filtration (at a constant pressure drop), filtrate flow rate varies inversely as the__________________?

   A. Square root of the velocity
   B. Square of the viscosity
   C. Filtration time only
   D. Washing time only

8. During washing of filter at the end of constant pressure filtration, the rate of washing equals the rate of filtration___________________?

   A. At time zero
   B. At the end of filtration
   C. When half the filtrate has been obtained
   D. At the end of filtration, but decreases with time subsequently

9. Filter medium resistance is important during the ______________ of filtration?

   A. Early stages
   B. Final stages
   C. Entire process
   D. None of these

10. Flow of filtrate through the cake in a plate and frame filter press is best described by the ______________ equation?

    A. Kozeny-Carman
    B. Hagen-Poiseuille’s
    C. Fanning’s
    D. Kremser