CleaverBrooks CB Ohio Special 100 HP, Руководство по эксплуатации, обслуживанию и запасным частям

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Chapter 3 — Waterside Care and Requirements
Part No. 750-184 3-17
Whichever method is used, common sense dictates a periodic
recheck of fireside and waterside conditions during lay-up to allow
variations from the above methods for special area or job-site
conditions.
Swing open the boiler head at the stack end of the unit to prevent
flow of warm, moist air through the boiler tubes.
Although pollution control regulations may continue to limit the
permissible sulphur content of fuel oils, care must be taken to avoid
corrosion problems that sulphur can cause, especially in a boiler
that is seasonally shut town. Dormant periods, and even frequent
shutdowns, expose the fireside surfaces to condensation below the
dew point during cooling. Moisture and any sulphur residue can
form an acid solution. Under certain conditions, and especially in
areas with high humidity, the corrosive effect of the acid will be
serious enough to eat through or severely damage boiler tubes or
other metal heating surfaces during the time that a boiler is out of
service.
The condition does not generally occur during normal firing
operation, because the high temperature of operation vaporizes any
condensation. However, proper boiler operation must be
maintained, especially with a hot water boiler, to prevent the flue
gases from falling below the dew point.
At the start of lay-up, thoroughly clean the fireside by removing any
soot or other products of combustion from the tubes, tube sheets
and other fireside surfaces. Brushing will generally suffice. Sweep
away or vacuum any accumulation. The fireside surfaces may be
flushed with water. However, all moisture must be eliminated after
flushing and the surface dried by blowing air or applying some form
of heat. It is good practice to protect the cleaned surfaces by coating
them with an anti-corrosive material to prevent rust.
To prevent condensation from forming in the control cabinet, keep
the control circuit energized. For extended lay-up periods, especially
where high humidity or large swings in ambient temperature occur,
the program relay should be removed and stored in a dr y
atmosphere.
Dry storage is generally employed when the boiler will be out of
ser vice for a significant period of time, or where freezing
temperatures may exist. In the dry storage method the boiler must
be thoroughly dried because any moisture would cause corrosion.
Both fireside and waterside surfaces must be cleaned of all scale,
deposits, soot, etc. Steps must be taken to eliminate moisture by
placing moisture-absorbing materials such as quick lime (at 2
pounds for 3 cubic feet of volume) or silica gel (at 5 pounds for 30
cubic feet of volume) on trays inside the vessel. Fireside surfaces
may be coated with an anti-corrosive material, or grease or tar
paint. Refractories should be brushed clean and wash-coated. All
openings to the pressure vessel, such as manhole and handholes,
should be shut tightly. Feedwater and steam valves should be
closed. Damper and vents should be closed to prevent air from
reaching fireside surfaces. Periodic inspection should be made and
absorption materials renewed.