Cleaver-Brooks CBH 40 - Forced Draft Fan; Fireside Cleaning; Lubrication

Chapter 5-Adjustment and Maintenance
damaging gasket. Start tightening at top center
and alternate between top center bolt and bottom
center bolt until both are drawn up-tight. Do not
overtighten. Continue tightening sequence along
top and bottom, tightening bolts alternately until
door is secured and gas tight. After boiler is back
in operation re-tighten the bolts to compensate for
any expansion.
NOTE: Proper sealing of doors is essential to
avoid leakage of combustion gases and
loss of heat and operating efficiency.
0. fORCED DRAfT fAN
The position of the impeller vanes with relation to
the air intake housing is extremely important to
the output capacity of the fan. The impeller vanes
should not rub or contact the air housing but at the
same time the clearance must not be more than
1/32". Spacing washers of various thicknesses are
used to obtain desired clearance.
Check occasionally to see that fan is securely
tightened to the motor shaft. Examine the vanes
for deposits of dust or dirt since these build ups
can cause a decrease in air capacity or lead to an
unbalanced condition.
If motor was replaced or if motor leads were dis-
connected, make sure that impeller rotation is
proper before starting operation. Rotation on most
models is counterclockwise when viewed from the
front of the boiler. Notice the direction arrow on
the impeller housing.
P. fiRESIDE ClEANING
Soot and non-combustibles are effective insulators
and if allowed to accumulate will reduce heat
transfer to the water and increase fuel con-
sumption. Soot and other deposits can be very
moisture absorbent and may attract moisture to
form corrosive acids which will deteriorate fireside
metal.
Clean-out should be performed at regular frequent
intervals depending upon load, type and quality of
fuel, internal boiler temperature, and combustion
efficiency. A stack temperature thermometer, if
used, can be a guide to clean-out intervals since an
accumulation of soot deposits will raise the flue
gas temperature.
Tube cleaning is accomplished by opening front
and rear doors. Tubes may be brushed from either
end. All loose soot and accumulations should be
removed. Any soot or other deposits should be
removed from the furnace and tube sheets.
Refer to Section N of this chapter for instructions
on properly closing front and rear heads.
5-22
The vent stub and stack should be cleaned at
regular intervals. Commercial firms are available
to perform this work. The stack should be in-
spected for damage and repaired as required.
The fireside should be thoroughly cleaned prior to
any extended lay-up of the boiler. Depending upon
circumstances a protective coating may be re-
quired. See Section J in Chapter 2.
Q. lUBRICATION
Electric Motors
Manufacturers of electric motors vary in their
specifications for lubrication and care of motor
bearings and their recommendations should be
followed.
Ball bearing equipped motors are pre-lubricated.
The length of time a bearing can run without
having grease added will depend upon many fac-
tors. The rating of the motor, type of motor en-
closure, duty, atmospheric conditions, humidity,
and ambient temperatures are but a few of the fac-
tors involved.
Complete renewal of grease can, when necessary,
be accomplished by forcing out the old grease with
the new. Thoroughly wipe those portions of the
housing around the filler and drain plugs (above
and below bearings). Remove the drain plug (bot-
tom) and free the drain hole of any hardened
grease which may have accumulated. With the
motor not running, add new grease through the
filler hole until clear grease starts to come out of
the drain hole. Before replacing the drain plug run
the motor for 10 to 20 minutes to expel any excess
grease. The filler and drain plugs should be
thoroughly cleaned before they are replaced.
The lubricant used should be clean and equal to
one of the good commercial grades of grease
locally available. Some lubricants that are dis-
tributed nationally are:
Gulf Oil -Precision Grease No. 2
Humble Oil -Andok B
Texaco -Multifak No. 2
Phillips -1 B + RB No. 2
Fiske Bros. -Ball Bearing
Lubriplate
Standard/Mobile -Mobilux No. 2
Control Linkage
Apply a non-gumming dripless high temperature
lubricant, such as graphite or a silicone derivative
to all pivot points and moving parts. Work lubri-
cant in well and wipe excess. Repeat application at
required intervals to maintain freedom of motion
of parts.
Solenoid valves and motorized valves require no
lubrication.