AEC 1426-i Twin-Shear Granulator - Manual (Page 22)

1426-i Granulator Chapter 5: Maintenance 21 of 37
Bed Knives
We recommend that the same screws and washers be re-used only when the bed knives have
been repositioned or re-ground. When blunt knives are discarded and replaced with new
knives, use new screws and washers. This will reduce the risk of screw failure due to their
overstretching. Screws and washers must be replaced with the type specified in the Spare
Parts List. Use the following procedure to replace or adjust the bed knives:
1. Access the cutting chamber as directed in Section 3-4 on page 14.
2. Remove the bed knife shield screws and lift off the bed knife shield.
3. Remove the screws holding the bed knives, and remove the bed knives.
4. Before installing and adjusting the bed knives, check all rotor knives to make sure
they are properly seated on the rotor and securely fastened.
5. Thoroughly clean the knife seats.
6. Replace the bed knives on the bed knife seat and tighten the screws until they are
finger-tight.
7. Use the adjustment screws to set the knife clearance to 0.10 mm – 0.15 mm (0.004” –
0.006”). The clearance should be measured with a feeler gauge at the ends of the
knife, by rotating the rotor sheave backwards by hand. The clearance is slightly
greater at the center of the knives.
8. Tighten the bed knife screws evenly and torque the 16 mm screws to 266 Nm (196 ft.
lbs.).
9. Replace the bed knife shield and adjust the shield using its push and pull screws so
that its front edge is within 1.6 mm (0.062”) of the bed knife edges. The downstroke
shield is adjusted with shims that are placed under the side tabs. Unused shims are
stored under the head of the screws on top of the tabs.
10. Make sure all screws, bolts, and nuts are properly tightened.