AEC Colortronic MTF 2000 Series Granulator - Manual (Page 22)

Tangential Feed Granulators Maintenance 22 of 39
Rotor Knives
We recommend that the rotor knife screws be replaced with new screws every sixth knife
change to reduce the risk of screw failure due to overstretching. Screws must be replaced
with the type specified in the spare parts list. Improper substitution could lead to premature
failure, equipment damage, and serious injury to personnel.
Caution! Rotor knives should be changed one seat at a time to prevent rotor from
being rotated in an out-of-balance condition.
1. Access the cutting chamber as directed in Section 3-3 on page 14.
2. Set back the bed knives to clear the rotor knives so that the rotor can revolve freely.
3. Loosen and remove the rotor knife screws. Make sure you have solid footing while
you apply the breaking force.
Note: These screws are tightened to a torque of 315 Nm (230 lbs./ft.), so make sure
you have the proper breaker bar.
4. Lift the knife off of the rotor.
5. Thoroughly clean the knife seats with a stone or other non-marring tool, and wipe the
screws with a lightly oiled cloth. Do not leave an oil film on the screws, as
lubrication can adversely affect the stress on a screw installed to a fixed torque value.
6. Place each knife section onto the rotor with the chamfered edge facing into the knife
seat, making sure that the backside of the knife is sitting squarely against the back of
the knife seat on the rotor.
7. Lightly tighten the screws and check that a 0.04 mm (0.0015”) feeler gauge will not
pass between the back of the knife and the knife seat. Tap the knife gently with a
rawhide hammer if necessary to close the gap.
8. Tighten the screws evenly and torque the screws to 315 Nm (230 lbs./ft.)
9. Re-check the gap between the back of the knife and the knife seat. If necessary,
readjust the knife.
10. Repeat steps 4 through 9 for each of the remaining knives.
11. Adjust the clearance between the bed knives and rotor knives. (See “Bed Knives” on
page 23.)