Combustion is the rapid oxidation of a fuel resulting in the release of usable heat and the production of a visible flame
Natural Gas With Air:
CH4 + 2O2 + 8N2 ———–>
CO2 + 2H2O + 8N2 + 1000 BTU Heat
Perfect Combustion Provides:
The hottest flameMinimum exhaust volume
Characteristics:
1. All fuel combusted
2. Blue near burner tile
3. Forms a yellow conical flame shape
4. Produces the highest flame temperature
5. Provides the minimum exhaust volume
1. Flue products oxidizing (Free O2)
2. Pale blue color
3. Forms a more conical flame
4. All fuel combusted
5. Flame temperature drops (Heating excess air)
1. Air starved or fuel rich
2. Carbon Monoxide and H2 formed
3. Reducing atmosphere
4. Flame color is predominantly yellow color
5. The flame is less defined
6. Flame temperature drops
1. Verify proper mix and directed air/fuel supply
2. Confirm that you have stable combustion
3. Check to make sure that the system is venting all the by-products of the exhaust flue gases
Air remaining after the fuel has been combusted
-or-
Air supplied in addition to the quantity needed for stoichiometric combustion
Primary Air —
1. Air mixed with the fuel prior to ignition
Secondary Air —
1. Air supplied to the flame after it is ignited
Secondary Air Effects —
1. Imprecise air/fuel ratio control
2. Exhaust volume increases
3. Fuel rate rises
4. Less available heat