WorksheetsCPE649: CONTROL DEVICES FOR GASEOUS CONTAMINANTS
Total questions: 15
Worksheet time: 8mins
The following are four treatment processes for gaseous contaminants.
Adsorption
Absorption
Combustion
Condensation
Vaporization
What are major gaseous contaminants from industry?
SOx
NOx
Hydrocarbon
O2
CO
What is adsorption?
Adsorption is the adhesion of molecules of gas, liquid, or dissolved solids into liquid
Adsorption is the collision of molecules of gas, liquid, or dissolved solids to a surface
Adsorption is the adhesion of molecules of gas, liquid, or dissolved solids to a surface
Adsorption is the vaporization of molecules of gas, liquid, or dissolved solids into the air
The following are examples of adsorbents.
activated charcoal
alumina
silica gel
zeolite
ammonia
Choose three types of absorber for adsorption?
Fixed bed
Moving bed
Sleeping bed
Fluidized bed
The following are the types of absorption unit.
Packed tower
Plate tower
Venturi scrubber
Spray tower
Cooling tower
What are the advantages of spray tower?
High efficiency of removal for low concentration of gaseous contaminant
Inexpensive to install and operate
Have less gas-liquid interfacial area
Little pressure drop
The following are the types of packing used in packed tower EXCEPT
Pall ring
Raschig ring
Berl saddle
Curl ring
Choose two types of condenser.
Surface condenser
Air condenser
Contact condenser
Spray condenser
Choose examples of combustion unit.
Flare
Catalytic combustion
Thermal combustion
Direct combustion
1. Absorbing liquid (water) is sprayed through contaminated gas
2. Water-contaminant solution falls downward
3. Clean gas exits through outlet valve at top of unit
4. Moisture eliminators reduce moisture in gas before release
The above are the mechanism for which equipment?
Plate tower
Spray tower
Packed tower
Scrubber
Venturi scrubber is suitable to control particulate and gaseous contaminants.
FALSE
TRUE
Air or water is usually used as cooling medium in condenser.
FALSE
TRUE
Which of the following are the disadvantages of flare?
Waste large amount of heat energy
Produce visible smoke
Burning off excess hydrocarbon
Cause formation of oxides of nitrogen due to burning at high temperature and long periods
The efficiency of catalytic combustion depends on the following factors:
Contaminant concentration
Contact time
Temperature of gas stream
Type of catalyst
CO2 concentration
