CPE649: CONTROL DEVICES FOR PARTICULATE CONTAMINANTS

The followings are the control devices for particulate contaminants.

• Settling chamber

• Cyclone

• Baghouse filter

• Fan

• Electronic precipitator

The velocity of the gas stream is reduced due to a large cross sectional area of settling chamber.

• TRUE

• FALSE

Choose the correct statements about cyclone.

• The centrifugal force is generated by spinning of gas

• Large diameter cyclone can remove particles 40 - 50 μm diameter

• d50 is diameter of particle that is collected with 50% efficiency

• Width of entrance, b = D/2

Which of the following is INCORRECT?

• Spray tower can remove both gaseous and particulate contaminants

• Wet cyclone scrubber can removes particle in size 5 to 50 micron with 90-98% efficiency

• Venturi scrubber can removes submicron particles of 0.5 to 5 micron like smoke and fumes

• Scrubber is not a type of wet collector

The following is INCORRECT about baghouse filter.

• Particulates are collected in a hopper at the bottom

• Use tubular or envelope-shaped

• The top of the filter bag is sealed to prevent air exit

• The bottom of the bag is opened to allow air entry

• The cleaned gas is flow at the bottom

High voltage electrostatic precipitator is used at large industrial plant such as coal-fired utility boilers.

• TRUE

• FALSE

Large area of collection plate of electrostatic precipitator is required for a high efficiency.

• FALSE

• TRUE

Efficiency of a control device is depend on the particle size.

• TRUE

• FALSE

Choose the correct rank on the efficiency of devices to remove 1 micron particles.

• cyclone > ESP > venturi scrubber > bag filter

• Bag filter > venturi scrubber > spray tower > ESP

• ESP > bag filter > spray tower > venturi scrubber

• Bag filter > ESP > venturi scrubber > spray tower

The following are types of centrifugal collector.

• Cyclone

• Dynamic precipitator

• Electrostatic precipitator

• Scrubber