How can the rate of drying be accelerated? (Choose the incorrect option)
Anonymous Quiz
9%
A) By increasing the air flow rate
12%
B) By raising the inlet air temperature
66%
C) By reducing the air velocity
13%
D) By dehumidifying the inlet air
How is the wet-weight moisture content of a solid represented?
Anonymous Quiz
9%
A) Water content as a percentage of the weight of the dry solid
79%
B) Water content as a percentage of the weight of the wet solid
4%
C) Water content as a percentage of the weight of the air
8%
D) Water content as a percentage of the weight of the water
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How is the Loss on Drying (LOD) calculated?
Anonymous Quiz
11%
A) [(wt of water in sample / wt of dry sample)] × 100
82%
B) [(wt of water in sample / wt of wet sample)] × 100
4%
C) [(wt of wet sample / wt of dry sample)] × 100
3%
D) [(wt of wet sample / wt of water in sample)] × 100
How is moisture content determined on a dry-weight basis?
Anonymous Quiz
4%
A) [(wt of water in sample / wt of wet sample)] × 100
87%
B) [(wt of water in sample / wt of dry sample)] × 100
7%
C) [(wt of wet sample / wt of dry sample)] × 100
2%
D) [(wt of wet sample / wt of water in sample)] × 100
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In the study of drying rate, what is plotted as moisture content versus time?
Anonymous Quiz
30%
A) Drying rate vs moisture content
57%
B) Moisture content vs drying time
5%
C) Drying time vs temperature
8%
D) Temperature vs moisture content
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In which period of the drying curve does the drying rate depend on the diffusion rate?
Anonymous Quiz
34%
A) Constant rate period
19%
B) First falling rate period
37%
C) Second falling rate period
10%
D) Equilibrium moisture period
When is continued drying considered a waste of time and energy?
Anonymous Quiz
4%
A) During the constant rate period
9%
B) During the first falling rate period
10%
C) During the second falling rate period
77%
D) After the equilibrium moisture period begins
Which type of solid is more difficult to dry?
Anonymous Quiz
8%
A) Crystalline solids
89%
B) Amorphous solids
2%
C) Solids with no pores
2%
D) Solids with large pores
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What is the major criterion for classifying dryers based on method of sample handling?
Anonymous Quiz
25%
A) Heat sensitivity of the material
61%
B) Presence or absence of agitation
8%
C) Nature of the liquid to be removed
5%
D) Scale of operation
Which of the following is not a classification of dryers based on method of sample handling?
Anonymous Quiz
3%
A) Static-bed dryers
3%
B) Moving-bed dryers
3%
C) Fluidized-bed dryers
91%
D) Vacuum dryers
In a tray dryer, how can the exposed surface area be increased?
Anonymous Quiz
5%
A) By increasing the temperature of the air
88%
B) By decreasing the thickness of the bed
3%
C) By increasing the size of the cabinet
3%
D) By increasing the number of trays
What type of dryer is the Turbo-Tray Dryer?
Anonymous Quiz
4%
A) Static-bed dryer
89%
B) Moving-bed dryer
4%
C) Fluidized-bed dryer
3%
D) Pneumatic dryer
In a Fluidized-Bed System, what is the state of the solids?
Anonymous Quiz
27%
A) Completely suspended in the gas stream
68%
B) Partially suspended in the gas stream
4%
C) Settled at the bottom of the dryer
1%
D) Adhered to the walls of the dryer
What is one advantage of using a Fluidized Bed Dryer?
Anonymous Quiz
2%
A) Lower drying rate
3%
B) Reduced heat and mass transfer
12%
C) More aggregation and migration of colo
83%
D) High drying rate due to efficient heat and mass transfer
Which type of dryer is suitable for drying granular solids?
Anonymous Quiz
5%
A) Static-bed dryer
3%
B) Moving-bed dryer
81%
C) Fluidized-bed dryer
12%
D) Pneumatic dryer
In Fluidized-Bed Systems, why does drying occur at a constant rate?
Anonymous Quiz
6%
A) The temperature is kept constant
17%
B) The drying gas is in continuous contact with the particles
69%
C) All the surface of particles is subjected to heat uniformly
8%
D) The particles are not completely dried
What is a desired characteristic of particles obtained from Fluidized Bed Dryers?
Anonymous Quiz
1%
A) More elongated particles
91%
B) More spherical, free-flowing particles
4%
C) More aggregated particles
5%
D) Greater migration of color
What type of materials can spray dryers handle?
Anonymous Quiz
9%
A) Solid materials
15%
B) Granular materials
74%
C) Fluid materials
2%
D) Coarse materials
What happens when liquid droplets contact the hot gas in a spray dryer?
Anonymous Quiz
76%
A) The surface liquid quickly evaporates
11%
B) The droplets become larger
9%
C) The droplets become sticky
4%
D) The droplets solidify
What type of particles are produced by spray drying?
Anonymous Quiz
90%
A) Intact spheres, spheres with buds, ruptured hollow spheres, or sphere fragments
5%
B) Irregularly shaped particles
4%
C) Granular particles
1%
D) Coarse particles