A suspension of glass beads in ethylene glycol has a hindered settling velocity of 1.7 mm/s, while the terminal settling velocity of a single glass bead in ethylene glycol is 17 mm/s. If the Richardson-Zaki hindered settling index is 4.5, the volume fraction of solids in the suspension is_____________?

Related Mcqs:

1. A 30% (by volume) suspension of spherical sand particles in a viscous oil has a hindered settling velocity of 4.44 μm/s. If the Richardson Zaki hindered settling index is 4.5, then the terminal velocity of a sand grain is_________________?

   A. 0.90 μm/s
   B. 1 μm/s
   C. 22.1 μm/s
   D. 0.02 μm/s

2. The capacity of a classifier in ‘tons of solid/hr’ is given by (where, A = cross-sectional area in m2, V = rising velocity of fluid in m/sec, S = percentage of solids in the suspension by volume, ρ = density of solids in kg/m3)_________________?

   A. 3.6 AVS.ρ
   B. 3.6 A.V.ρ
   C. 3.6 A.S. ρ
   D. 3.6 AVS/ρ
   Answer: Option

3. In classification, particles are said to be equal settling, if they have the same terminal velocities in the_______________?

   A. Different fluids
   B. Same fluid
   C. Same field of force
   D. Both B. and C.

4. For a sphere falling in the constant drag co-efficient regime, its terminal velocity depends on its diameter D. as_________________?

   A. d
   B. √d
   C. d2
   D. 1/d

5. The work index in Bond’s law for crushing of solids has the following dimensions__________________?

   A. No units (dimensionless)
   B. kWh/ton
   C. kW/ton
   D. kWh.m1/2/ton

6. 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

7. Particle size range in which dust catcher (gravity settling chamber) works most effectively and efficiently is ______________ microns?

   A. < 5
   B. 10 to 25
   C. < 74
   D. > 1000

8. Two particles are called to be equal settling, if they are having the same ?

   A. Size
   B. Specific gravity
   C. Terminal velocities in the same fluid & in the same field of force
   D. None of these

9. Gravity settling process is not involved in the working of a________________?

   A. Hydrocyclone
   B. Classifier
   C. Dorr-thickener
   D. Sedimentation tank

10. Sorting classifiers employing differential settling methods for separation of particles make use of the differences in their_________________?

    A. Particle sizes
    B. Densities
    C. Terminal velocities
    D. None of these