22
CAUTION
Do not touch hot surfaces.
The upper limit of the blower operation is 400º F (205º C). Do not touch
the blower while it is in operation and assure blower is cool when not in
operation.
CAUTION
Use of a thermowell insulates the thermocouple. Invalid and delayed
readings will result. This can result in ineffective protection devices.
NOTE
The upper temperature limits are not intended for continuous operation.
Consult with factory for detailed information assistance.
6.4 STOPPING
CAUTION
Do not stop the blower if there are high outlet pressures in the outlet piping.
Unload the outlet piping prior to shutting down the blower.
Stop the blower by turning off the motor. Isolate the blower from the vacuum system and vent the blower
to atmosphere. Turn off the cooling water, if water cooled. Stop the backing pump. Refer to component
instruction manual.
6.5 METHANE GAS APPLICATIONS
Instructions for injecting fuel oil, kerosene, and lube oil into blowers sludged
by methane digester (sewage) gas:
Some sewage gases will adhere to the
rotors in a gas blower. If enough sludge from the gas being pumped builds
up on the rotors, it destroys the clearances between the rotors. The build-up
can cause the blower to clatter and eventually freeze up when the rotors no
longer have clearance to turn. This can be easily prevented by periodically
fl ushing the blower with a mixture of 75% kerosene or fuel oil and 25%
lubricating oil. The kerosene or fuel oil dissolves the sludge buildup and the
lubricating oil coats the rotors to slow the build-up. The mixture should be
injected on the inlet side through a valve set to feed a gallon of mixture in 15-
20 minutes. On units regularly fl ushed, once a week is suffi cient. If the unit
is dirty, it should be fl ushed daily until the hard build-up is removed then put
on a weekly cycle. In very dirty gas installations, the cycle must be varied to
meet the demand.
6.6 WATER INJECTED BLOWERS
Water injected into the inlet of a blower operating on vacuum service will cool the blower. The water absorbs
the heat of compression as it passes through the unit along with the air/gas being compressed. A blower
cooled in this manner can operate safely at higher vacuums or higher inlet temperatures than a normally
uncooled unit.
The amount of water required depends on the inlet air/gas temperature, inlet vacuum, water temperature,
and the maximum discharge temperature desired. Check with the factory or sales representative for
additional guidance.
FLUSHING
FLUID
CONTROL
VALVE
Figure 10 - Flushing Diagram
