Page 12 - February 2021 Track N Times

TECHNICAL TRAINING

Dust System Tips and Tricks

By Mark Riola, Assistant Manager Specialized Maintenance

Here are some tips to keep your dust system operating properly, which will help
extend the life of air filters, bearings, bushings, electric motors, fans and many oth-
er machine components as well as keep the machine yellow. The longer your dust
discharge system is inoperable, the more problems you will encounter. The grind
dust will absorb moisture from the air and turn into a paste. Once this paste dries
it solidifies like concrete and becomes very difficult to remove from the dust col-
lector, auger troughs and discharge tubes.
During your daily machine inspection, you should command on all augers and ro-
tary valves from the HMI. While walking your inspection check that each compo-
nent is running. Those that are not running, turn off the disconnect switch and
move on. Once finished with lower deck inspection, do your top deck machine
inspection. Power down each grind car, open electrical room doors and reset all
tripped breakers. Once done up top, return to the ground and revisit each discon-
nect switch you shut off. For rotary valves, stand looking at the fan on the motor
and flip on the disconnect switch for a second. If rotary valves run, leave it be and Plugged Auger
check on it an hour later. If it attempts to run but stalls, turn the disconnect back
off. If you didn’t notice any movement, check the breaker and see if it immediately
tripped again – this could mean bad breaker, contactor, wire or motor. You will
need to do electrical troubleshooting.
So, if it attempted to run, there is something binding the rotors or the non-drive
end bearing is seized. LOTO the disconnect switch. Take a 10mm wrench and
remove the 4 nuts and lock washers mounting the motor to the gearbox. Tap on
the motor side to side to free it from the gearbox, remove and set on the bogie
truck. Just to verify the motor will run you can flip the disconnect switch on and
observe the motor. LOTO the disconnect switch again if removed. Now, take a
garbage bag and wrap it around the gearbox so no grind dust contaminates the oil.
Loosen the 15/16 bolt directly under the disconnect switch leaving plenty of
threads to support the weight of the rotary valve. Remove the rest of the 15/16
bolts on the rotary valve and spin the rotary valve 180 degrees to allow access to
the rotors. Clean out all dust and check to see if something is jammed between
the rotors and case. Sometimes a blower fan weight will fall off the fan and end up
in the rotary valve. If this is the case, use a screwdriver and carefully spin the gear
inside the gearbox to back off the rotors and allow you to free the object. Once Cleaned Auger
rotors are cleared, leaving the rotary valve spun out 180 degrees, set the motor
back on the gearbox, making sure it is fully seated. Keep fingers, clothing and tools
clear of the exposed rotors, and flip on the disconnect switch. If rotary valve runs, your good to reassemble. If it still
doesn’t run, turn off the disconnect, take a small ballpeen hammer and hit the rotors a few times being careful not to
damage them, and also hit the shaft on each side, gearbox and bearing side a few times. Check again to see if it will

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