Question

Answer the following MCQs

1. Which type of control device works well only for large particulate matter?

1. Baghouse
2. Electrostatic Precipitator
3. Cyclone
4. Absorber

2. What characterizes a temperature inversion aloft?

1. Temperatures lowering as altitude increases and then temperatures increasing with altitude.
2. Temperatures increasing with altitude and then temperatures decreasing as altitude increases. C.
3. Temperatures steadily decreasing as altitude increases.
4. Temperatures steadily increasing as altitude increases.

3. How does a baghouse remove contaminants?

1. Absorption
2. Adsorption
3. Filtration
4. Centrifugal separation

4. How does a cyclone remove contaminants?

1. Absorption B. Adsorption C. Filtration D. Centrifugal separation

1. Absorption
2. Adsorption
3. Filtration
4. Centrifugal separation

5. What is likely to happen if the sampling velocity in a stack is higher than the actual velocity in the stack?

1. Under sample small particles
2. Over sample small particles
3. Under sample big particles
4. Over sample big particles

Answer 1

Dear student

1.) ( C )

  

Cyclone Separator

A cyclone separator is a separation device that uses the principle of inertia to remove particulate matter from flue gases in these separators, dirty flue gas enters a chamber containing a vortex, similar to a tornado. Because of the difference in inertia of gas particles and larger particulate matter, the gas particles move up the cylinder while larger particles hit the inside wall and drop down. This separates the particulate matter from the flue gas, leaving cleaned flue gas.

2.). ( D )

  Temperature inversion, a reversal of the normal behaviour of temperature in the troposphere (the region of the atmosphere nearest the Earth's surface), in which a layer of cool air at the surface is overlain by a layer of warmer air. (Under normal conditions air temperature usually decreases with height.). But here temprature increase with altitude

3.) ( C )

A fabric filter, sometimes referred to as a baghouse, utilizes fabric filtration to remove particles from the contaminated gas stream by depositing the particles on fabric material. The filter's ability to collect small micrometer and sub-micrometer particles is due to the accumulated dust cake and not the fabric itself. The filter is usually in the form of cylindrical fabric bags, hence the names "fabric filter" or "bag house", but it may be in the form of cartridges that are constructed of fabric, sintered metal or porous ceramic. In general, fabric filters are capable of collection efficiencies greater than 99 percent.

4 .) .( D )

cyclones use centrifugal force to spin the dust particles and throw the particulates upon the collector's wetted walls.