Four Steps for Cleaning Disc Springs
Changing screens comes with a laundry list of tasks. While you have screen decks apart for routine maintenance or surprise repairs, take time to clean the disc springs.
You must remove dust that has accumulated on the disc spring on the tensioning elements every time you change the screen insert. If you leave dust, you’ll find the tension-element function restricted. This means you’ll be unable to apply tensioning force evenly through each disc and loose spring.
Properly cleaned tension elements have longer life and ensure a proper tension on the screen inserts.
Step 1: Access the disc spring
The first step in cleaning the disc spring is accessing it. The locking ring (indicated by arrow C in the illustration) has to be dismantled to ensure that dust can be fully removed between the individual disc spring elements. During disassembly, be sure to use a magic marker to label or number layers in the spring column. This step ensures you will have the proper arrangement after re-assembly.
Step 2. Clean with a brush
You can then clean the individual disc spring with only a brush—and no other cleaner.
Step 3. Reinstall tensioning elements
Once you’ve cleaned inside, you must reinstall the tensioning elements. Damaged discs with traces of cold welding or hairline cracks are to be replaced.
Don’t forget to grease the thread with high-temperature paste. This prevents cold-welding in the thread during plant operation. If cold welding has already occurred in the thread, the tensioning hook must be replaced.
To allow fast installation of new screen inserts, the team at Ammann recommends keeping the proper number of well-maintained tensioning elements on hand. If there are two sets, you can pop the clean and maintained inserts into place and put the dusty ones aside for cleaning later. This allows you to install all elements at the same time.
Removed tensioning elements can then be cleaned during regular plant operation and stored until needed.
Step 4. Get the tensioning right
The last step in this process is to properly adjust the tension of each screen insert, with the proper gauge and according to the instructions in the manual. Screen inserts stretch during the duration of their use. The most stretching occurs with new inserts—as temperatures and tension are applied for the first time. Only properly pre-tensioned screen inserts will be effective for extended periods.
For more information, contact Ammann Group at https://www.ammann.com/en/.