fluidization

Question 1

These compounds are chlorinated to alkyl chlorides in a single fluidized form.

a. Olefins
b. Ethylene
c. Alkaline
d. Chlorine

Answer 1

a. Olefins

Question 2

Naphthalene is oxidized by air to form phthalic anhydride in a bubbling fluidized reactor.
What kind of reaction does this produce?

a. Endothermic Reaction
b. Exothermic Reaction
c. Intrinsic Reaction
d. Extrinsic Reaction

Answer 2

b. Exothermic Reaction

Question 3

This compound is produced by reacting propylene, ammonia, and oxygen (air) in a single fluidized bed of a complex catalyst.

a. Ammonium
b. Acrylonitrile
c. Alkyl Chloride
d. Aniline

Answer 3

b. Acrylonitrile

Question 4

They developed a successful Fischer-Tropsch synthesis reactor based on a dilute-phase transport-reactor concept.

a. Silverman Co.
b. Shell Development Co.
c. Kellogg Co.
d. Graham and Way Co.

Answer 4

c. Kellogg Co.

Question 5

The purpose of fluidized beds in the production of polyethylene prevents ____ since the unit is operated near the melting point of the product.

a. weak sports
b. strong foundation
c. hot spots
d. cold spots

Answer 5

c. hot spots

Question 6

This is normally carried out in a fluidized bed to achieve mixing of the gasses and temperature control.

a. Homogeneous Reactions
b. Heterogeneous Reaction
c. Homogeneous Mixing
d. Heterogeneous Mixing

Answer 6

a. Homogeneous Reactions

Question 7

This category covers the greatest commercial use of fluidized beds other than fluid catalytic cracking.

a. Homogeneous Reactions
b. Heterogeneous Reaction
c. Homogeneous Mixing
d. Heterogeneous Mixing

Answer 7

b. Heterogeneous Reaction

Question 8

Use of fluidized bed that is advantageous for close control conditions so that a predetermined amount of free moisture may be left with the solids to prevent dusting of product during subsequent material handling operations.

a. Incineration
b. Combustion
c. Drying
d. Calcination

Answer 8

c. Drying

Question 9

This process uses fluidized beds of thermoplastic resins to facilitate the coating of metallic parts. A properly prepared, heated metal part is dipped into the fluidized bed, which permits complete immersion in the dry solids.

a. Coating
b. Combustion
c. Incineration
d. Drying

Answer 9

a. Coating

Question 10

When a fluid is passed downwards through a bed of solids, no relative movement between the particles takes place, unless the initial orientation of the particles is _____.

a. Moving
b. Flowing
c. Stable
d. Unstable

Answer 10

d. Unstable

Question 11

When can we consider the bed fluidized?

a. If the velocity is then increased further, the individual particles separate from one another and become freely supported in the fluid.
b. If the velocity is then decreased and the particles flow as a one bulk.
c. If the velocity is then increased further, the individual particles move as one with the fluid.
d. If the velocity is then decreased making the particles flow individually.

Answer 11

a. If the velocity is then increased further, the individual particles separate from one another and become freely supported in the fluid.

Question 12

A type of fluidization when the bed continues to expand as the velocity particles increase and it maintains its uniform character, with the degree of agitation of particles increasing progressively.

a. Particulate Fluidization
b. Emulsion Phase
c. Bubble Phase
d. Aggregative Fluidization

Answer 12

a. Particulate Fluidization

Question 13

A type of fluidization when a gas, uniform fluidization is frequently obtained only at low velocities. At higher velocities two separate phases may form. A continuous phase is often referred to as the dense or the ____.

a. Particulate Fluidization
b. Emulsion Phase
c. Bubble Phase
d. Aggregative Fluidization

Answer 13

b. Emulsion Phase

Question 14

When gas bubbles pass through a relatively high-density fluidized bed the system cloely resembles a boiling liquid, with the lean phase corresponding to the vapour and the dense or continuous phase corresponding to the liquid

a. Boiling Bed
b. Emulsion Phase
c. Bubble Phase
d. Quiescent Bed

Answer 14

a. Boiling Bed

Question 15

As the superficial velocity approaches the minimum fluidizing velocity, the bed starts to ____.

a. The bed starts to contract and when the particles are in physical contact with another the bed is fluidised.
b. The bed starts to contract and when the particle are no longer in physical contact with one another the bed is fluidised.
c. The bed starts to expand and when the particles are no longer in physical contact with one another the bed is fluidised.
d. The bed starts to expand and when the particles are in physical contact with another the bed is fluidised.

Answer 15

c. The bed starts to expand and when the particles are no longer in physical contact with one another the bed is fluidised.

Question 16

If the velocity is now increased again, What is to be expected to the curve (FE).

a. If the velocity is increased again, it might be expected that the curve (FE) would be retracted and that the slope would suddenly change from 1 to o at the fluidising point.
b. If the velocity is increased again, it might be expected that the curve (FE) would be reduced and that the slope would suddenly change from 1 to o at the fluidising point.
c. If the velocity is increased again, it might be expected that the curve (FE) would be expanded and that the slope would suddenly change from o to 1 at the fluidising point.
d. If the velocity is increased again, it might be expected that the curve (FE) would be retracted and that the slope would suddenly change from o to 1 at the fluidising point.

Answer 16

a. If the velocity is increased again, it might be expected that the curve (FE) would be retracted and that the slope would suddenly change from 1 to o at the fluidising point.

Question 17

How can you relate the pressure drop corresponding to ECD to buoyant weight of particles?

a. In an ideal fluidised bed the pressure drop corresponding to ECD is greater than to the buoyant weight of particles per unit area.
b. In an ideal fluidised bed the pressure drop corresponding to ECD is equal to the buoyant weight of particles per unit area.
c/ In an ideal fluidised bed the pressure drop corresponding to ECD is less than to the buoyant weight of particles per unit area.
d. In an ideal fluidised bed the pressure drop corresponding to ECD is not equal to the buoyant weight of particles per unit area.

Answer 17

b. In an ideal fluidised bed the pressure drop corresponding to ECD is equal to the buoyant weight of particles per unit area.

Question 18

This is defined as the ratio of the diameter of the sphere of the same specific as the particle d.

a. Particle Shape
b. Fluidising Velocity
c. Particle
d. Surface volume

Answer 18

a. Particle Shape

Question 19

This equation relates the Galileo number Ga to the Reynolds number in terms of the voidage at the incipient fluidisation point.

a. Pressure Drop Equation
b. Bernoulli Equation
c. Ergun Equation
d. Ergun Law

Answer 19

c. Ergun Equation

Question 20

A type of fluidization in which the fluid velocity is increased, the bed continues to expand and remains homogeneous for a time.

a. Particulate Fluidization
b. Catalytic Fluidization
c. Bubbling Fluidization
d. Fluidizing Bed

Answer 20

a. Particulate Fluidization

Question 21

A type of fluidization in which the gas passes through the bed as voids or bubbles which contain few particles, and only a small percentage of the gas passes in the spaces between individual particles

a. Particulate Fluidization
b. Catalytic Fluidization
c. Bubbling Fluidization
d. Fluidizing Bed

Answer 21

c. Bubbling Fluidization

Question 22

Another type of behavior in fluidization in which it can occur in bubbling since the bubbles tend to coalesce and grow as they rise in the bed.

a. Stripping
b. Aggregative
c. Slugging
d. Particulate

Answer 22

c. Slugging

Question 23

What happens when a fluid flows upward through a packed bed of particles at low velocities?

a. The particles increase in velocity
b. The particles decreases in velocity
c. The particles remain stationary
d. The particles move upward

Answer 23

c. The particles remain stationary

Question 24

This refers to when true fluidization occurs is the minimum porosity for fluidization.

a. The porosity of the bed
b. The porosity of the particulates
c. The increase in velocity of particles
d. The decrease in velocity of particles

Answer 24

b. The porosity of the particulates

Question 25

How can the minimum voidage be determined? a. It can be determined experimentally by subjecting the bed to a rising gas stream and measuring the height of the bed b. It can be determined theoretically by correlating the rising gas stream and measuring the height of the bed c. It can be determined experimentally by subjecting the bed to the pressure drop and the height of the bed. d. It can be determined by correlating the height of the bed and the velocity of the

Answer 25

a. It can be determined experimentally by subjecting the bed to a rising gas stream and measuring the height of the bed

Question 26

The fluidization velocity at which bubbles are first observed is called ____. a. Bubbling Velocity b. Maximum bubbling velocity c. Minimum bubbling velocity d. Critical bubbling velocity

Answer 26

c. Minimum bubbling velocity

Question 27

This is described as the flow of fluids. An operation intermediate in character between the flow of solids through fluids. a. Fluidization of Solids b. Fluidizing velocity c. Separation using fluid d. Bubbling velocity

Answer 27

a. Fluidization of Solids

Question 28

The driving force in fluidization a. Pressure Gradient b. Temperature Gradient c. Concentration Gradient d. Heat Gradient

Answer 28

a. Pressure Gradient

Question 29

What happens when the velocity of the fluid and the pressure drop are increased? a. The bed expands and the oscillation of each particle increases in velocity and extent b. The bed expands and the oscillation of each particle decreases in velocity and compresses. c. The bed compress and the oscillation of each particle increases in velocity and extent d. The bed compresses and the oscillation of each particle decreases in velocity and compresses.

Answer 29

a. The bed expands and the oscillation of each particle increases in velocity and extent

Question 30

A type of fluidization in which the fluid literally begins to "bubble" through the solid bed is a manner identical to the action observed in bubbling. a. Aggregative Fluidization b. Minimum Fluidizing c. Particulate Fluidization d. Heat Gradient

Answer 30

a. Aggregative Fluidization

Question 31

What happens when the fluid velocity is increased in the bubble section? a. The bubbling action becomes more and more violent b. The bubbling action becomes less and less violent c. There is no change in the bubbling action d. The bubbling actions remains the same.

Answer 31

a. The bubbling action becomes more and more violent

Question 32

This is a convenient criterion for determining whether of not a given system will be fluidized in a particulate or aggregative fluidization. a. Reynolds Number b. Froude Number c. Prandtl Number d. Smitch Number

Answer 32

b. Froude Number

Question 33

What happens when a superficial velocity of the fluid exceeds the free-settling velocity of the solid particles? a. The particle takes on a motion relative to the container in the same direction as the motion of the fluid. b. The particle takes on a motion parallel to the container in the opposite direction of the motion of the fluid. c. The particles takes on a motion perpendicular to the container in the similar direction of the fluid d. The particles remain stationary and do not move at all.

Answer 33

a. The particle takes on a motion relative to the container in the same direction as the motion of the fluid.

Question 34

Differentiate the fluidization that happens between low-density particles and large dense ones. a. Fine low-density particles fluidize more evenly than large dense ones, provided that they are not so small that the London-van der Waals attractive forces are great enough for the particles to adhere together strongly. b. Fine low-density particles fluidized faster than large dense ones, provided that they are not so small that the London-van der Waals attractive forces are are great enough for the particles to adhere together strongly. c. Fine low-density particles fluidized slower than larger dense ones, provided that they are larger than the London-van der Waals attractive forces. d. Fine low-density particles fluidized while large dense particles does not fluidized at all.

Answer 34

a. Fine low-density particles fluidize more evenly than large dense ones, provided that they are not so small that the London-van der Waals attractive forces are great enough for the particles to adhere together strongly.

Question 35

Describe the drag, attraction and gravity forces when it is classified as aeratable. a. Drag and gravitational forces are minimal while attraction is high. b. Drag and gravitational forces is greater than the attraction force. c. Drag and gravitational forces is high and the attraction force is minimal. d. Drag and gravitational forces is high and the attraction force is almost negligible.

Answer 35

b. Drag and gravitational forces is greater than the attraction force.

Question 36

Describe the drag, attraction and gravity forces when it is classified as spoutable.  a. Drag and gravitational forces are minimal while attraction is high. b. Drag and gravitational forces is greater than the attraction force. c. Drag and gravitational forces is high and the attraction force is minimal. d. Drag and gravitational forces is high and the attraction force is almost negligible.

Answer 36

d. Drag and gravitational forces is high and the attraction force is almost negligible.

Question 37

Describe the drag, attraction and gravity forces when it is classified as cohesive. a. Drag and gravitational forces are minimal while attraction is high. b. Drag and gravitational forces is greater than the attraction force. c. Drag and gravitational forces is high and the attraction force is minimal. d. Drag and gravitational forces is high and the attraction force is almost negligible.

Answer 37

a. Drag and gravitational forces are minimal while attraction is high.

Question 38

Describe the drag, attraction and gravity forces when it is classified as bubbling. a. Drag and gravitational forces are minimal while attraction is high. b. Drag and gravitational forces is greater than the attraction force. c. Drag and gravitational forces is high and the attraction force is minimal. d. Drag and gravitational forces is high and the attraction force is almost negligible.

Answer 38

c. Drag and gravitational forces is high and the attraction force is minimal.

Question 39

What are the disadvantages of fludizing beds? a. bubbling beds of fine particles are difficult to predict. Rapid mixing of solids causes non uniform residence times for continuous flow reactors. Particles break-up because of this process. b. Bubbling beds of large particles are difficult to predict Rapid mixing of solids causes non uniform residence times for continuous flow reactors. Particles breakup because of this process. c. Bubbling beds of large particles are difficult to predict Rapid mixing of solids causes non uniform residence times for continuous flow reactors. Particles breakup because of this process. d. Bubbling beds of large particles are difficult to predict Rapid mixing of solids causes non uniform residence times for continuous flow reactors. Particles breakup because of this process.

Answer 39

a. bubbling beds of fine particles are difficult to predict. Rapid mixing of solids causes non uniform residence times for continuous flow reactors. Particles break-up because of this process.

Question 40

What are the advantages of fluidizing beds? a. liquid-like behavior is easy to control and automate. Rapid mixing, uniform temperature and concentration. Slow to respond to rapid temperature changes. Useful for large and small operations. Heat and mass transfer rates are high, requiring smaller surfaces. b. liquid-like behavior is hard to control and automate. Slow mixing, uniform temperature and concentration. Fast to respond to rapid temperature changes. Useful for large and small operations. Heat and mass transfer rates are high, requiring smaller surfaces. c. liquid-like behavior is easy to control and automate. Rapid mixing, uniform temperature and concentration. Slow to respond to rapid temperature changes. Useful for large and small operations. Heat and mass transfer rates are low, requiring larger surfaces. d. liquid-like behavior is easy to control and automate. Rapid mixing, heterogenous temperature and concentration. Slow to respond to rapid temperature changes. Useful for large and small operations. Heat and mass transfer rates are low, requiring larger surfaces.

Answer 40

a. liquid-like behavior is easy to control and automate. Rapid mixing, uniform temperature and concentration. Slow to respond to rapid temperature changes. Useful for large and small operations. Heat and mass transfer rates are high, requiring smaller surfaces.