Mechanical centrifugal collectors are not suitable for the collection of:

Mechanical centrifugal collectors are not suitable for the collection of:

a. very course particles
b. course particles
c. fine particles
d. rough particles
e. heavy particles

Answer: C

When combustion gases contain SO2,

When combustion gases contain SO2,

a. use of wet scrubbers should be discontinued
v. SO2 with water will form strong alkaline solution
c. the scrubbing water may be treated with lime or dolomite to control water pH
d. SO2 does not react with water
e. higher alkalinity is good for the water.

Answer: C

In an electrostatic precipitator the:

In an electrostatic precipitator the:

a. discharge electrode is negatively charged
b. collector electrode is negatively charged
c. discharge electrode is positively charged
d. particles are positively charged
e. discharge electrode and the particles are positively charged

Answer: A

Solid pollutants such as fly-ash are produced when burning:

Solid pollutants such as fly-ash are produced when burning:

a. natural gas
b. heavy fuel oil
c. wood
d. coal

Answer: B,C & D.

Wet scrubbers remove:

Wet scrubbers remove:

a. gases only
b. gases and dust only
c. particulate only
d. acidic gases only
e. dust only

Answer: B

An advantage of a wet scrubber over the bad filters is that they:

An advantage of a wet scrubber over the bad filters is that they:

a. are less expensive
b. are easy to operate
c. removes CO2
d. remove ash particles larger than 300 microns
e. simultaneously removes dust and gaseous pollutants

Answer: E

Liquid pollutants emitted from power plants include:

Liquid pollutants emitted from power plants include: 

a. water at elevated temperatures
b. waste water from flue gas scrubbing
c. waste water from water treatment processes
d. waste water from ash handling operations

Answer: A, B, C & D.

Solid pollutants emitted from power plants are:

Solid pollutants emitted from power plants are: 

a. dust
b. soot
c. flyash
d. carbon monoxide
e. sulphur dioxide
f. sulphuric acid

Answer: A, B & C.

Fly ash is normally less than:

Fly ash is normally less than:

a. 1 mm in diameter
b. 0.3 mm in diameter
c. 1,000 microns in diameter
d. 300 microns in diameter
e. 30 microns in diameter

Answer: E

The voltage supplied to an electrostatic precipitator is between:

The voltage supplied to an electrostatic precipitator is between:

a. 10,000 volts AC and 1,000,000 volts AC
b. 10,000 volts DC and 100,000 volts DC
c. 1,000,000 volts AC and 1,000,000 volts AC
d. 100,000 DC and 1,000,000,000 volts AC
e. 100,000 AC and 10,000 volts DC

Answer: B

Fly-ash is removed from bag filters by a system of:

Fly-ash is removed from bag filters by a system of:

a. rollers
b. hammers
c. electrostatic precipitators
d. shakers
e. rappers

Answer: E