What is secondary air utilized for_________________?
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Answer: A. provide air around burners for obtaining optimum combustion
Explanation
Secondary air is supplied around burners in a furnace to ensure complete combustion of the fuel gas mixture. While primary air mixes with fuel during initial feeding, secondary air provides the extra oxygen needed for thorough combustion. This deliberate air staging prevents unburned hydrocarbons from escaping and maximizes thermal energy release in boilers. Furnace combustion efficiency depends heavily on precise control of primary, secondary, and tertiary air supply streams. Primary air dries and transports pulverized coal into the combustion chamber, initiating volatile matter ignition. Secondary air is introduced surrounding the burner flame front to complete the oxidation of carbon monoxide into carbon dioxide.
Option B transport and dry the coal is the specific function performed by primary air streams in pulverizer systems. Option C conversion of carbon monoxide happens as a result of supplying secondary air, but option A directly defines its purpose. Option D air delivered by induced draft fan represents flue gas evacuation rather than secondary burner combustion air.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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