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
Related Mcqs:
- 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 - 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. - In washing type plate and frame filter press, the ratio of washing rate to the final filtrate rate is__________________?
A. 4
B. 1/4
C. 1
D. 1/2 - 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. - The filtrate flow rate in constant pressure filtration___________________?
A. Continuously increases
B. Continuously decreases
C. Remain constant throughout
D. May increase or decrease; depends on the pressure - 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) - Filtration operation carried out by continuous increase of the inlet pressure of slurry, is called the _____________ filtration?
A. Constant rate
B. Varying pressure
C. Varying rate
D. Constant pressure - 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 - Filter medium resistance is important during the ______________ of filtration?
A. Early stages
B. Final stages
C. Entire process
D. None of these - 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.
