Fireside Cleaning; Upper Pass Cleaning - CleaverBrooks FLX Operation, Service And Parts Manual

Chapter 7
operator with an excellent opportunity to perform a detailed
check of all components of the boiler, including piping,
valves, pumps, gaskets, refractory, etc. Complete cleaning,
spot painting or repainting, and the replacement of
expendable items, should be planned for and taken care of
during this time. If possible, any major repairs or
replacements that may be required should be taken care of
during the boiler shutdown.
Replacement spare parts, if not on hand, should be ordered
well in advance of a shutdown.
Note: Cleaver-Brooks genuine parts should
be used to ensure proper operation and to
avoid damage to the equipment.
Cleaver-Brooks boilers are designed, engineered and built to
give long life and excellent service. Good operating practices
and consistent maintenance and care will promote efficiency
and economy of operation and contribute to many years of
reliable performance from the equipment.
Cleaver-Brooks offers a Planned Maintenance Program that
covers many of the items included on this chapter. For more
information on the Planned Maintenance Program, contact
your local Cleaver-Brooks authorized representative.
C. FIRESIDE CLEANING
Soot and other noncombustible deposits are effective
insulators and, if allowed to accumulate on boiler heat
exchanger surfaces, will reduce heat transfer to the water and
increase fuel consumption. Soot and other deposits can
absorb moisture and may attract moisture in the form of
corrosive acids that will deteriorate fireside metal.
Inspection and cleanout should be performed at frequent
intervals, depending upon the boiler's load, type and quality
of fuel, internal boiler temperature, and combustion
efficiency. Stack temperature can be used as a guide to
determine cleanout intervals, since an accumulation of soot
deposits will raise the stack temperature.
Access to the furnace for tube and refractory cleaning is
provided through a hinged burner door at the front of the
boiler. When opening the burner door, first shut off the
electrical and fuel supplies and then disconnect all fuel lines
at the burner watching to see that there is no interference with
field installed piping, wiring, or other obstructions. A
temporary platform must be placed inside the furnace in order
to protect the bottom drum insulating refractory when
working inside the furnace.
! DANGER WARNING
To avoid the hazard of electrical shock,
which could cause serious personal injury
or death, the use of a low voltage flashlight
Is recommended when working Inside the
boiler furnace area.
7-2
Tubes should be brushed with a wire brush to remove any
soot or other accumulations. Refractory surfaces should be
cleaned, if necessary, with a soft bristle brush. Loose material
should be vacuumed from the bottom of the furnace.
D. UPPER PASS CLEANING
Upper pass access is gained through removal of the inner and
outer side casing. To remove the outer casing panels, first
disconnect and remove any electrical conduit, boxes and
brackets attached to the side outer casing. Match mark the
outer panels for repositioning. Remove screw (if installed)
from frame above each outer panel. Starting with center
panel, slide panel up, swing bottom of panel away from boiler
and then slide down from the upper frame and set panel aside.
After the center panel(s) are removed, the end panels can be
slid (approximately 1") towards the center until they free
from the corner frame and then removed in the same manner
as the center panel(s). It there are only two outer panels
(Models 150 through 350), then slide one end panel further
into the corner frame to allow the other panel to slide free
from the corner frame. If obstructions are present, such as the
gas train, there may not be enough room to slide the panel out
from under the upper frame. In this case, unscrew the upper
frame from the roof and side frames and remove it also.
Match mark all inner casing panels for repositioning later.
Inner casing panels must be removed in sequence starting
from either end. Remove nuts, washers and clamp angles
from the end and bottom of panels. Remove nuts, washers
and bolt bars from vertical seams. Loosen nuts on top clamp
angles but don't remove until panel is ready to be removed.
Inner casing panels can not be removed by pulling panel
straight out from boiler because of a 1" gasket retaining strip
that overlaps behind the panels. Remove inner casing panels
by sliding or angling panel away from remaining panels until
the 1" retaining strip has cleared panel and then panel can be
removed and set aside.
After removing the inner side casing, the pass cover plates
(2nd pass only) must be removed. The cover plates are
screwed together and are held in place by tabs inserted
between the tubes. Remove the insulation by starting at one
end and carefully rolling it up. The insulation blocks can now
be removed from the pass opening. Keep the insulation
blocks in order once they have been removed so they can be
re-installed in the same position. Insulation is removed from
the 4th pass in the same manner.
Now that the 2nd (left side) and 4th (right side) pass openings
are exposed, cleaning can be done in the same way as the
furnace area. Since the 3rd pass is only open on the ends,
cleaning is done by pushing a wire brush mounted on a long
handle, through from each end. Since the arc of movement is
restricted, cleaning the 3rd pass must be done from both sides
of the boiler. The fifth pass is cleaned from above the tubes.
As in the furnace, loose material should be removed by
vacuuming after brushing. The pressure vessel should be
inspected for any signs of deterioration after cleaning.
Inspection and Maintenance
750-177