Dickinson Pacific - The Fuel Air Mixture

38
THE FUEL AIR MIXTURE
It’s easy to underestimate the importance of air flow when operating a natural draft diesel appliance. In order for a
natural draft diesel appliance to operate safely and burn cleanly without soot or smoke, adequate air flow into the cabin
is vital. The correct balance of fuel and air must always be established inside the burner to ensure clean and trouble free
operation. Below are some examples of burning conditions to be avoided and tips on how to correct them.
INCORRECT X
Blue-yellow flames inside the burner pot
INCORRECT X
Dirty orange-red flames
INCORRECT X
Dirty orange-red flames inside the burner pot
CORRECT
Blue-yellow flames above the burner ring only
Too much air, burning too lean
Corrective actions:
• Turn fan off, or reduce speed
• Adjust barometric damper open in ¼” increments
• Increase fuel in small increments
FUEL
AIR
FUEL
AIR
AIR
FUEL
AIR
FUEL
Too much fuel, burning too rich
Corrective actions:
• Turn fan on, or increase speed
• Adjust barometric damper closed
• Reduce fuel in small increments
Not enough fuel or air
Corrective actions:
• Turn on fan or increase fan speed
• Make sure the fresh air vent is open and unblocked
• Test the cabin for positive pressure (see page 40, fig 80 for
draft test)
• Check that the air holes in the burner are unblocked
A balanced mix – burns clean and hot
When operating correctly;
• The flames should be yellow in color.
• You may also see some blue flame.
• The flame should produce no smoke.
• You should see very little liquid fuel inside the burner pot
• Portions of the burner parts may glow red hot
• There should be no dusting of soot on the viewing window
FIG 74
FIG 75
FIG 76
FIG 77