Core component of wet mechanical waste pre-treatment
The BTA® Waste Pulper is a central component of every BTA® Hydro-mechanical Treatment. It was developed primarily to achieve three goals:
- The dissolution and defibration of as much fermentable organic matter as possible for subsequent biogas production..
- The separation of non-fermentable or fermentable heavy fractions (stones, bones, glass, batteries, metallic objects, etc.) as heavy fraction.
- The separation of non-fermentable or fermentable fractions (textiles, wood, plastics, foils, etc.) as light fraction.
The BTA® Waste Pulper makes use of the natural forces of buoyancy and sedimentation to separate the waste mixture into its fractions. For this purpose, the waste is mixed with a process water blank in the BTA® Waste Pulper after coarse pre-shredding.
However, the principle of the BTA® Waste Pulper goes beyond this mixing and additionally concentrates the stirring energy introduced in order to defibrate and dissolve biomass quickly and effectively.
The decisive product is thus an easily manageable, pumpable organic suspension that contains 90% of the fermentable organic fraction of the waste.
The organic suspension produced is drawn off through a perforated screen of 10 mm. Accordingly, it still contains sand and fine sedimentable particles and is fed to the sand separation by the BTA® Grit Removal System in the next step.
Impurities are removed efficiently and gently with the help of a sluice located at the bottom of the pulper for the heavy fraction (metal, bones, glass, stones, batteries, etc.) and a rake - LRS Rake - or an external screw - LRS Screw - for the light fraction (mainly plastics, wood, textiles, foils, etc.).
The heavy fraction is transported via a classifying screw into a collection container. The light fraction can be collected with the help of a rake (LRS Rake) and discharged via a funnel into a screenings press, where it is dewatered to a dry matter content of approx. 35-40 %. Alternatively, after separation of the organic suspension and the heavy fraction and renewed addition of process water, the pulper contents are discharged and separated externally in a classifying screw (LRS Screw).
Correctly executed, the principle of the BTA® Waste Pulper is the most efficient way of waste separation with the aim of maximum biogas production.