Sterlco BP800 Series Granulators - Manual (Page 29)

800 Series beside-the-press Chapter 5: Maintenance 29 of 43
Removing and Replacing Bed Knives
This procedure should be performed only by 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.
Before replacing the bed knife with new or sharpened knives, whip off 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, wipe 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.
It is recommended that the knife bolts be replaced with each new set of
knives. This will reduce the risk of bolt failure due to overstretching.
Always use the specified replacement bolts.