Agricon’s technicians are often asked why we run new Die Rings in? The answer is that the holes on a mild steel, case hardened Die Ring are drilled individually with drill bits. These holes can be rough on the inside and takes on the drill bit’s grooves. These “untreated” holes are rough and creates difficulty to get material through the holes and make pellets. Such Die Rings can be problematic to start producing pellets and can easily block up.
The solution is to get the holes smooth before using the Die Ring for pelleting, also called “running-in of the Die Ring”. We do this with a mixture of very fine plastering sand, cooking oil, maize kernels and some roughage in the end. (Recipe and steps available from Agricon). This mixture is actually a grinding paste that serves the same purpose as sandpaper. Passing this through the Die Ring, we smooth the holes out and the Die Ring will become very easy to use in future pelleting.
- Check the condition of the Rollers.
- Worn Rollers are not suitable for running in a new Die Ring. Ideally a new set of Rollers should be kept for this purpose and for spares.
- Make sure that the new Die Ring has the same size holes as the original, if not replace the hammer mill sieve with the correct size. (An 6mm Die Ring with a 6mm sieve on the hammer mill, an 8mm Die with a 6 or 8 mm sieve on the hammer mill etc., but never a larger than 8mm sieve.)
- The following mixture of 20kg must be used to run inn your Die Ring properly:
o 70 % Clean dry plaster sand (no rocks and as fine as possible)
o 15% Whole maize
o 15% Vegetable Oil (Use old Fish and Chips oil to save money)
o Run this mixture through your Die Ring for 30 minutes by recycling it through the machine and adding oil and maize if it dries out in the process.
o The aim is not to make pellets as it will block the Die Ring, but the sand the holes Run the pellet machine with the “running in” mixture for at least 30 minutes. Soft pellets will form after approximately 5 minutes. Keep on feeding these pellets back into the machine and add oil if the mixture is getting too dry. Add maize if the mixture makes very hard pellets to avoid too much compaction.
o End of with clean maize until no more sand comes through
o Slowly start feeding your mixture into the machine. Slowly increase the feeding tempo taking care not to “burn” the Die Ring.
- Install the Rollers and adjust until it touches the Die Ring and spins along freely without stopping. Before Stopping the Pelleting machine.
- Stop feeding the mixture into the pelleting machine and start to slowly feed clean whole maize (or another suitable cleaning product) into the machine until the maize pellets emerges.
- Let the machine run until the amps stabilise and the Die Ring is empty.
- This procedure should be done every time when you stop to clean the Die Ring and prevent blockage of the Die Ring.
- Now you can stop the mill. Follow Lock-out procedure. Now open the front covers, grease the Rollers and leave the machine covers open to cool down.