Sterlco BP800 Series Granulators - Manual (Page 27)

Chapter 5: Maintenance 27 of 41
Removing and Replacing Bed Knives
NOTE: This procedure should be performed only be a qualified operator or maintenance
engineer. Protective gloves must be worn to avoid injury when handling the cutting knives!
To remove and replace bed knives, use the following procedure.
1. Open the granulator by following the steps “Removal and Replacement of the
Screen.”
2. Open the rear-closing panel by releasing the locking latch.
3. Pivot the in-feed hopper completely back to gain clear access to the cutting
chamber; clear any process material or foreign objects from between the knives.
4. Rotate the rotor so that the rotor knives will not interfere with the removal of the
bed knife. Using a wooden block, block the rotor to prevent it from rotating
while removing the knives.
5. Loosen the lock nuts and back off the adjustment screws.
6. Loosen and remove the bed knife shield bolts and remove the shield, positioned
above the knife. The remaining bed knife bolts and bed knife may now be
removed.
7. Perform the above steps to remove the rear (upstroke) bed knife as well.
NOTE: Before replacing the bed knife with new or sharpened knives, whip the
knife seats on the knife block, being sure to clean off all process material. The
tapped holes in the knife block (used for holding the knives in place) should be
clear of any dirt, oil, or process material.
8. Install new or sharpened bed knives on each knife seat, making sure that the rotor
is blocked to prevent it from rotating while installing each knife. Be sure to place
the bed knives in the correct positions:
a. The rear (upstroke) bed knife must be placed with the extended cutting
edge on the bottom.
b. The front (downstroke) bed knife should be placed with the cutting edge
on the top.
9. Before re-installing the knife bolts, whip them clean with a light oil-damp cloth.
Do not leave an oil film on the bolt since lubrication can adversely affect the
stress on the bolt when torqued to the specified values.