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.
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 - 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. - 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. - 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 - 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 - 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) - 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 - 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 - Filter medium resistance is important during the ______________ of filtration?
A. Early stages
B. Final stages
C. Entire process
D. None of these - 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
