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_______________?

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. 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....

3. 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....

4. 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...

5. Addition of filter aid to the slurry before filtration is done to _______________ of the cake?

   A. Increase the porosity B. Increase the compressibility co-efficient C. Decrease the porosity D. Decrease the compressibility co-efficient...

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. 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...

8. The specific cake resistance for incompressible sludges is (where ΔP = pressure drop over cake)__________________?

   A. ∝ ΔP B. ∝ 1/ ΔP C. ∝ √ΔP D. Independent of ΔP...

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

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

10. In filtration, the use of ‘filter aid’ helps in__________________?

    A. Reducing the filtration pressure B. Accelerating the rate of filtration C. Deplugging the filter medium D. Enhancing the cake porosity in case of a dense impermeable cake...