Regarding to flow characteristics, the viscosity can be changed in the following system
Anonymous Quiz
34%
a-Newtonian system
3%
b- Plastic system
10%
c- Pseudoplastic system
5%
d-dilatant
48%
e. All plastic, pseudoplastic and dilatant
Regarding selection of appropriate mixer, Which type of mixer is suitable for thicker pastes and plastic masses mixing?
Anonymous Quiz
17%
a-Sigma blade mixer
12%
b-Turbine of flat blade design
55%
c-Sigma-blade mixer and muller mixer
9%
d-Muller mixer
7%
e-Twin-shell mixer
The phenomenon of turbulent mixing is characterized by
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53%
a-Random fluctuation of the fluid velocity at any given point within the system
12%
b-Organized fluctuation of the fluid velocity at any given point within the system
28%
c- Random fluctuation of the fluid velocity at the center within the system
3%
d-Stable velocity of the fluid at any given point within the system
3%
e-None of the above
Two or more ingredients in separate or roughly mixed condition are treated so that each particle of any one ingredient is as nearly as possible adjacent to a particle of each of the other ingredients, the
process is known as
process is known as
Anonymous Quiz
9%
a- milling
81%
b-mixing
3%
c-drying
5%
d-clarification
2%
e- centrifugation
❤1
Regarding mixing, mixing mechanisms for two dissimilar liquids in which the shear that is generated stretches the interface
between them is
between them is
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10%
a-Bulk Transport
7%
b- Turbulent Mixing
52%
c-Laminar Mixing
8%
d-Molecular Diffusion
22%
e- All of the above
Regarding vortex in mixing, Vortex develops at the center of the vessel when liquids are mixed by a centrally-mounted vertical-shaft impeller and can be overcoming by
Anonymous Quiz
6%
a- changing arrangement of the impeller
8%
b- changing the tank geometry
18%
c-using baffles
7%
d-using diffuser ring
60%
e. All of the above
Regarding flow characteristics, which of the following is a characteristic of turbulent flow?
Anonymous Quiz
15%
a- Velocity components at a given point in the flow field remain constant
18%
b- Fluid particles move in parallel layers
50%
c-The fluid has different instantaneous velocities at different location at the same instant in time
4%
D- The flow of fluid is smooth and ordered
13%
e-None of the above
Regarding mixing, the following categories are all mixing mechanisms of fluid, EXCEPT
Anonymous Quiz
63%
a-Radial motion
8%
b- Bulk transport
10%
c-Turbulent flow
4%
d-Laminar flow
14%
e-Molecular diffusion
Concerning in line liquid mixer, what is the most appropriate answer regarding in line
(continuous liquid mixing)
(continuous liquid mixing)
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12%
a- The in line liquid mixing produces an uninterrupted supply of freshly mixed material
24%
b- It is often desirable when very large volumes of materials are to be handled
10%
c- It can be accomplished essencally either in a tube through which the material flows or ....
5%
d- devices such as vanes, baffles, are placed in the mixing tub
49%
e- All of the above
😢2
The milling mechanisms could be comminution mechanisms.
Anonymous Quiz
4%
A-Cutting
2%
b-Attrition.
10%
c-Compression.
4%
d. Impact.
81%
e- All of them
Regarding miling techniques, which of the following techniques is applied to overcome the polymorphism problem during milling?
Anonymous Quiz
25%
a-Using a hammer mill
37%
b- Using wet milling
14%
c-Using cutter mill
13%
d-Increase milling temperature.
11%
e-None of the above
Regarding to the selection of mill technique, the choice of a mill is based on
Anonymous Quiz
5%
a-Cost
3%
b-Health hazards
3%
c-Cooling system
10%
d. Particles size
80%
e- All of the above
Regarding the concept of milling, what is milling?
Anonymous Quiz
5%
A-The process of increasing the size of solids
79%
b. The process of reducing the size of solids
9%
C-The process of converting solids into liquids
3%
d. The process of separating solids from liquids
5%
e-The process of randomization of dissimilar materials
Regarding the size distribution, what is the conventionally used unit for expressing size in
milling?
milling?
Anonymous Quiz
5%
a-Micron
7%
b-Millimeter
5%
c-Meter
82%
d. Mesh
1%
e- Nanometer
Rerarding measuring the size, which method can be used for measuring the size distribution
of particles
of particles
Anonymous Quiz
7%
a-Microscopy
9%
d-Sieving and sedimentation
10%
b-Sieving
3%
c-Sedmentation
71%
e- Sieving sedimentation, and microscopy
❤1👍1
Regarding factors influencing milling, what Happens to materials with low melting points
during milling?
during milling?
Anonymous Quiz
9%
a-They remain unchanged
58%
B-They become soft and plastic
16%
c-They get degraded
12%
d-They become explosive
6%
E-They get hydrated
Regarding milling industrial process, what factor can hinder comminution and produce a
sticky mass upon milling?
sticky mass upon milling?
Anonymous Quiz
4%
a-Particle shape
54%
b-Moisture content
7%
c-Polymorphism
3%
d. Temperature
33%
e- All of the above
Regarding techniques of milling, what is the effect of an increase in moisture on the rate of
milling to a specified product size?
milling to a specified product size?
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10%
a-It increases the rate of milling
51%
b-It decreases the rate of milling
8%
c-It has no effect on the rate of milling
8%
d-It depends on the type of material being milled
22%
e-Increase moisture content to 5% lead to wet milling
———— is a measure of the resistance to permanent deformation
Anonymous Quiz
20%
a-Young's modulus
13%
b- Elastic region
11%
c-Fracture point
6%
d-Plastic region
50%
e-Yield point
Regarding milling equipment, used for tough, fibrous materials
Anonymous Quiz
11%
a-roller mills
68%
b- cutter mills
12%
c- hammer mills
8%
d-ball mills
2%
e-fluid energy mills