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To extend the operating life of the atomizer, the following operating
and cleaning tips will simplify required maintenance:
- When the flow of oil and steam to the atomizer has been shut-off,
remove the atomizer from the burner.
- Place the atomizer nozzle end down in solvent, kerosene, or diesel
oil. This is especially important when firing heavy oils which tend
to harden in the atomizer making dismantling and cleaning extremely
difficult. Note: Coen recommends that the atomizer always be submerged nozzle
end down whenever it is removed from the burner, regardless of how clean
it may appear to be from the steam purging procedure.
- Utilize a burner ready rack with solvent trays and appropriate tools
for dismantling and cleaning. This will encourage proper and timely
maintenance and significantly increase the operating life of nozzle
caps and other nozzle parts.
- Keep spare atomizers on hand so that clean parts can be exchanged
for the dirty parts without causing lengthy burner downtime.
Frequency of Cleaning
The frequency of cleaning atomizers is dependent upon several conditions,
including:
- OIL CLEANLINESS. New and overhauled
systems often include foreign material in the lines which may obstruct
atomizer parts. In such situations, the the atomizer should be cleaned
and inspected within the first several hours of operation or in any
instance of abnormal performance.
- OIL QUALITY & TYPE vary widely,
with some oils burning more cleanly and carbon free than others.
- THE OPERATING CONDITIONS of the
equipment also effects frequency of cleaning. Abnormal draft or atomizing
medium conditions may cause more rapid fouling by carbon formation.
In general, the atomizer operation should be closely observed with frequent
inspection cleanings to monitor the condition of the atomizer and to establish
a specific cleaning schedule. The cleaning interval can be extended to
the maximum time consistent with the specific system and operating conditions.
From past experience cleaning intervals under stable operating conditions
typically range from 8 to 24 hours of burner operation with heavy fuels,
but often much longer with lighter fuels.
Cleaning the Atomizer
After the atomizer is removed from the burner tube and placed in the
solvent tray for cooling, the nozzle cap my be removed and cleaned
as follows.
- Place the atomizer in the rack and vise with the flats of the mixer
sleeve set in the open top vise opening.
- Remove the nozzle with an open wrench, tapping lightly. Removal of
the cap should be easy unless it has been overheated or allowed to cool
containing heavy oil.
- Clean the cap by washing and brushing it with a soft brass
or wire brush. DO NOT use an electric wire wheel for cleaning
or damage to the nozzle will result. Also, scraping is not recommended,
but if required, care should be taken not to mar any surface or edge
of an orifice.
- When it is clean, blow or wipe dry the nozzle cap and carefully set
it aside.
Once the nozzle cap is cleaned the nozzle body can be cleaned
the same way as the nozzle cap. Remove the nozzle body with the same open
end wrench by tapping lightly and inspect and clean as necessary.
CAUTION: Do not use a pipe wrench in place of
the open end wrench. A pipe wrench will distort the burner parts making
reassembly without leakage virtually impossible.
If the atomizer has been immersed in solvent, the mixer can now
be removed easily from its cavity in the mixer sleeve. The mixer assembly
may or may not utilize a whirlplate on the exit.
If the mixer is not free, back out the whirlplate holding screw, insert
a 10-24 machine screw, and remove it with a pair of pliers. If there is
no whirlplate, insert the 10-24 machine screw in the center threaded hole
and remove with pliers as before.
If overheating or the accumulation of heavy cold oil in the mixer prevents
the mixer from being easily removed from the sleeve, the mixer sleeve
must first be removed:
- Unscrew the mixer sleeve from the steam tube with the mixer inside
of it.
- Strike the furnace end of the mixer sleeve smartly against a solidly
positioned wooden block or other non-metal surface to drive the mixer
toward the open end.
- If the mixer still cannot be removed, insert a 3/8-inch brass rod
or wooden block into the mixer inlet and strike smartly with a hammer.
Be careful not to hit the thin walled oil entry sleeve of the mixer.
- If necessary, soak the mixer sleeve in penetrating oil or solvent
and repeat the prior steps.
If the mixer is the type with a whirlplate, remove the whirlplate retaining
screw and remove the whirlplate. If necessary, soak in penetrating oil
or solvent and use a sharp edged knife blade placed between the mixer
and whirlplate to carefully pry the whirlplate off. Check for deformation
or burrs and repair as necessary.
Thoroughly wash the mixer with solvent and blow out with compressed air.
Sight through all passages to ensure that they are clear and clean. Under
no circumstance use drills or other hard rods to clean orifices. These
methods will adversely affect the performance of the mixer.
Reassembly of the Atomizer
With the nozzle cap, nozzle body, and mixer cleaned and inspected, reassemble
the atomizer as follows:
- If the mixer requires a whirlplate, carefully re-position it, re-install
the retaining screw and tighten snugly with a screw driver.
- Insert the mixer into the mixer sleeve exposing approximately two
threads of the mixer sleeve.
- With the mixer inserted, attach the nozzle body to the mixer sleeve
and hand tighten. Now, attach the nozzle cap to the nozzle body, and
also hand tighten.
- To seat the mixer into the oil tube, hand tighten the mixer sleeve,
nozzle body and cap assembly until the mixer bottoms out on the oil
tube. Back the entire assembly off one turn and tighten with the lock
nut.
- With an open end wrench and light hammer, tap lightly to tighten.
Do not over tighten.
- With all parts assembled and tightened, the atomizer is ready for
its next use.
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