
Komptech -Pre-Treatment for Digestion System
In this process, various types of organic waste are prepared for liquid fermentation (dry matter less than 12%m). They can include packaging and contamination. Preshredding, using a Terminator and screen drum or Crambo, prepares the material for subsequent dissolution and contrary separation. The latter is done in 3 steps. Step 1 is pulping, step 2 is a combination of Multistar wet screening with screw press, and step 3 is settling of the fines in a settling tank. Putting the material through this process before fermentation helps give the fermenter a long life. With shredding and screening, integrating hygienization (less than 12mm) into the process is no problem. The eccentric screw pump at the outlet of the separation tank forms the interface to the biological process. Fermentation substrate preparation is an all-in solution, consisting of machines, electrics including visualization, pipelines and all measuring, control and regulation equipment.
Shredding
The process starts with the Crambo dual-shaft shredder. Its teeth and screen basket are configured for the materials. If the input contains a large amount of plastic, a combination of Terminator and screen drum can be used. Either way, the job of these low-speed shredders is to shred and open up the packaging of the organic content.
Contrary Separation - Pulper
The preshredded material is taken by screw conveyor to one or two pulpers. There, the dry matter proportion is adjusted in batch operation (add material, add water, mix, discharge). Inert and heavy items are removed by contrary sluices.
Contrary Separation – Wet Screen
The fraction from the pulper is taken from the pulper to a wet screen with a screen cut of 12 mm. The >12mm fraction is pressed out in a screw press. The dry matter leaves the process while the wet goes to the settling tank. The fine fraction from the <12mm screen goes directly to the setting tank.
Contrary Separation - Settling Tank
Since the <12mm fraction still contains sand and similar matter, separation by settling is needed. A clever structure with baffles and sand removal screw conveyors gives a substrate that is almost completely free of any fines.
Transfer to Fermenter
From the settling tank, the cleaned fermentation substrate passes through a tube macerator, which shreds the fibres to prevent rafting in the fermenter. The substrate then goes to an eccentric screw pump, which serves as the interface to the anaerobic digestion process.