For a cyclone of diameter 0.2 m with a tangential velocity of 15 m/s at the wall, the separation factor is__________________?

Related Mcqs:

1. Velocity of a small particle of diameter ‘Dp’ at a distance ‘r’ from the rotational axis of a cyclone rotating at an angular speed ‘ω’ is given by (the other symbols are as per standard notation) ?

   A. [(DP/18). (ρs – ρ/μ)] ω2r
   B. [(DP2/18). (ρs – ρ/μ)] ω2r
   C. [(DP/18). (ρs – ρ/μ)] ω2r2
   D. [(DP2/18). (ρs – ρ/μ)] ω2r

2. In the cyclone separator used for separation of dust from dust laden gas, the gas ?

   A. Enters the cyclone from the top
   B. Is admitted tangentially at high velocity
   C. Develops a helical motion inside the chamber
   D. Both B. and C.

3. Height of liquid in agitation tank is normally maintained equal to the tank diameter. However, if the tank is too tall and a large liquid hold up is desired, then two or more impellers mounted on the same shaft may be used. The clearance between the tank bottom and the bottom most impeller should be about (where, D = impeller diameter) ?

   A. 0.5 D
   B. D
   C. 1.5 D
   D. 2 D

4. Equivalent diameter of a particle is the diameter of the sphere having the same __________________?

   A. Ratio of surface to volume as the actual volume
   B. Ratio of volume to surface as the particle
   C. Volume as the particle
   D. None of these

5. Sauter mean diameter is the same as the ______________ mean diameter?

   A. Mass
   B. Arithmetic
   C. Volume-surface
   D. Geometric

6. 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

7. Theoretical capacity of crushing rolls in tons/hr is given by (where, V = peripheral velocity, m/sec. W = width of rolls, m Dr = distance between rolls ρ = density of material to be crushed, kg/m3 here, V =πND where, N = speed of the rolls in rotation per second (rps) D = diameter of rolls, m) ?

   A. 3.6 V.W.Dr.ρ
   B. 3.6 V.W. ρ
   C. 3.6 W.Dr.ρ
   D. 3.6 V.W.Dr/ρ

8. 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_____________?

   A. 0.1
   B. 0.4
   C. 0.6
   D. None of these

9. 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

10. For spheres, the surface shape factor is given by (where, A = area, V = volume, and D = diameter) ?

    A. π = (A/D2)
    B. π/6 = (V/D3)
    C. AD/V
    D. None of these