Combustion and Emission Flashcards
What is combustion
Chemical process of rapid oxidation of fuel products
What three things are needed for combusion
Fuel. oxygen, Heat (Ignition)
What are fuels
Hydrocarbons
(Made up of carbon and hydrogen)
How do atmospheric burners work
Use kinetic energy from the flow of gas which creates pressure drop making air go into burner via atmospheric pressure
How much air is primary air
1/3
How much air is secondary air
2/3
How much air for perfect combusion
10 ft
How much air for excess air
5 ft
How much air for dilution air
15 ft
Where is a forced draft burner
Fan before the burner
Where is an induced draft burner
Fan after the burner
Does forced draft need dilution air
No
What is tertiary air used for
Controls Nox
What is perfect combustion called
Stoichiometric
What is the incomplete combustion formula
fuel+02+N2=C02+H20+N2+C0+Aldehydes
What percent in combustion is NO
95%
When does N02 form
Once is atmosphere
What does Nox create when mixed with other pollutants
Ozone and acid rain
What is Nox made up with
N01 and N02
How is thermal Nox made
Through high temps oxidation of nitrogen in combustion
What temperature is Nox created
2200 F
Who is SOX created
Combustion of fuels containing sulfer
What makes up SOX
SO2 and SO3
Is Sox dependant on the size of the burner design of the boiler
NO
What percent of sulfer in the fuel will be SOX
95%
What ppm must heating oil stay under to avoid creating SOX
500PPM
What particulate emissions does wood create
Carbon particulates
Soot
unburned wood dust
PAH
semi-volatile organic compounds
Ash (metals, dust, minerals)
How much less CO2 is created from using natural gas verses Oil and Coal
30% -oil
45%-coal
How is CO created
Incomplete combustion
Disruptions of air/fuel mixture
Failing inducer
Gas pressure too high
Not enough combustion air
What is the explosion limit of CO
12.5% or 125000 PPM
Is CO lighter or heavier than air
Slightly Lighter
How much CO can be produced when properly set up
Less then 3
Max level of CO in air free
400
What problems can look like too much excess air but is a CO problem
Leaking site glass
Refractory issue
Cracked heat exchanger