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Determining
Burner Pattern:
To establish the correct spray pattern, try a hollow cone nozzle with an
80 degree spray angle (a popular angle in the industry). If the pattern
is not satisfactory change to a solid cone nozzle. Reducing nozzle angle
in 10 degree increments from 80 degrees is a good way to find proper angle.
(Mobile home units usually require 90 degree spray angles. |
Noisy
Fires
Pulsation and thumping or rumbling can be most objectionable to a homeowner.
It's possible in some cases to correct the situation by proper nozzle selection.
- If
the unit is fired with a solid cone nozzle, try a hollow cone or
Type W nozzle.
- If
the unit is fired with a 60 degree nozzle, the noise level can
be reduced in most cases by going to a wider angle.
- Check
to make sure the pump pressure is properly set.
- Check
the nozzle spray to be sure it is satisfactory. If the nozzle is
clogged, it may be impossible to ignite the resulting spray.
- Check
the spray pattern. Above 2.00 GPH, some burners give delayed ignition
with the hollow cone sprays, in which case a solid cone nozzle
may be the answer.
- Sometimes
the next size smaller nozzle will help. Also, the smaller droplets
will burn cleaner decreasing the amount of soot and dirt.
- Installing
a delayed opening solenoid valve on the nozzle line can usually
help pulsation during start up or shutdown.
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Cold
Oil
Outside storage tanks can be a source of burner problems because oil
becomes more viscous as the temperature drops. This, in turn, can result
in slow ignition, collapsing sprays and noisy fires. There have been
some cases where the oil was so cold it would not flow through the
pipe.
Although
some success with special nozzles has been reported, the
surest cure for this problem is to increase the pump pressure
to 120-125 psi and use the next size smaller nozzle. The
extra energy from the pump will atomize the heavier oil,
resulting in better ignition and a more stable flame. |
Delayed
Ignition
Check the following items:
- Check
for proper electrode setting.
- Check
the insulators for cracks or for a conducting coat
of soot of oil. Cracks sometimes occur under the electrode
bracket, causing a short circuit.
- Check
to see that the air shutter isn't too wide open.
Nozzle |
GPH |
A |
B |
C |
45
degrees |
(.75-4.00) |
1/8" to
3/16" |
1/2" to
9/16" |
1/4" |
| 60
degrees |
(.75-4.00) |
1/8" to
3/16" |
9/16" to
5/8" |
1/4" |
| 70
degrees |
(.75-4.00) |
1/8" to
3/16" |
9/16" to
5/8" |
1/8" |
| 80
degrees |
(.75-4.00) |
1/8" to
3/16" |
9/16" to
5/8" |
1/8" |
| 90
degrees |
(.75-4.00) |
1/8" to
3/16" |
9/16" to
5/8" |
0 |
Recommended Electrode Settings
NOTE:
Above 4.00 GPH, it may be advisable to increase dimension
C by 1/8" to insure smooth starting. When using double
adapters; (1) Twin ignition is the safest and is recommended
with settings same as above. (2) With single ignition, use
the same A and B dimensions as above, but add 1/4" to
dimension C. Locate the electrode gap on a line midway between
the two nozzles. |
Furnace
Room Odors
In the case of furnace room odor, check
these items:
- Check
the draft over the fire and make sure it is at least
.02 inches of water column. If it's lower than that,
check for obstructions in the flues, or for poor chimney
draft.
- Check
to be sure that the unit is not being over fired.
- Check
to see that there is not too much air through the burner.
- Delayed
ignition also can be a cause of odors.
|
Smoky
Fires
Since there are a number of possible causes, it follows that there are
several things to check:
- Check
the air handling parts of the burner. Maker sure the
fan blades, air intake and air vanes in the combustion
head are clean. If dogs or cats are kept in or near
the furnace room, it's not uncommon to find hair in
the oil burner fan.
- Check
combustion chamber or the burner tube for damage. In
the case of a stainless steel chamber, it might be burned
through in one or more places. Or in the case of a brick
chamber, some of the bricks might have become dislodged,
leaving openings. Sometimes a burner end cone will be
burned off or warped.
- Check
the nozzle for contamination. If clogged, it could produce
an off-center fire resulting in smoke.
- Going
to a size smaller nozzle might eliminate smoke.
Spray
Impingement
Spray
Impingement corrected by using a narrower spray angle
-
Check
to see if nozzle spray angle is too wide for the
burner air pattern. In this case, smoke may form
at the side of the fire. The solution is to select
the next narrower spray angle.
-
A
solid cone spray pattern in a burner with a hollow
air pattern will produce a smoky center in the fire.
This can be corrected by changing to a hollow cone
nozzle of the proper spray angle.
-
Check
for spray impingement on the walls or floor of the
combustion chamber, or at the end of the burner
tube. This is a cause of carbon build-up and smoky
fires. It's usually corrected by the proper choice
of spray angle, or by going to solid cone spray
pattern. If it's at the end of the burner tube,
you may have to relocate the nozzle.
|
Off-Center
Fires
- May
be caused by off center location of the nozzle in the
burner tube. The nozzle tube or bracket may be bent
or improperly located.
- If
the heavy flame always appears on the same side in a
particular burner, this is due to a particularity of
the air pattern in that burner and it can't be corrected
by changing nozzles.
- A
nozzle contaminated by sludge or other foreign matter
will usually produce an off- center fire.
- A
hollow air pattern will sometimes pull a solid cone
spray over to one side, causing an off-center fire.
This can be corrected by changing to a hollow cone nozzle.
|
Long
Fires
A narrow spray angle always produces a long fire. High viscosity oil
also can be a cause since the spray angle tends to collapse. As mentioned
before, this can sometimes be solved by increasing pump pressure and
going to the next size smaller nozzle. Solid cone nozzles also produce
a longer fire. |
