15. If liquid density and viscosity remains constant, then the Reynolds number in a stirred tank reactor will vary with the
A.impeller diameter
B.square root of the impeller diameter
C.square root of the impeller diameter
D.cube of the impeller diameter
16. What is the ratio of depth of liquid in vessel to the diameter of tank (H:Dt)?
A.1 : 1
B.2 : 1
C.4 : 1
D.none of these
17. Radial flow impellers
A.provide high shear conditions for breaking up bubbles
B.direct flow towards the walls of the reactor
C.Both (a) and (b)
D.provide low shear conditions and are suited for use in shear sensitive procesess
18. Transient flow range of mixing speed is obtained for
A.Rei<10
B.10
D.None of these
19. A typical ceiling fan would be best described as a(n)
A.radial flow impeller
B.axial flow impeller
C.intermig impeller
D.Rushton turbine
20. What is the ratio of diameter of impeller to the diameter of tank (Da:Dt)?
A.1 : 3
B.2 : 1
C.4 : 1
D.1 : 5
21. The reason of using a flat disk in a Turbine is
A.to create high shear conditions
B.to break up bubbles more efficiently than the impeller blades
C.to ensure that the bulk of the energy consumption occurs at the blades
D.all of the above
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