Assessing the process performance of ballistic separators in packaging waste sorting plants using sensor-based process monitoring

Waste Management & Research The Journal for a Sustainable Circular Economy, vol. 44, pp. 1603–1619

Abstract

To effectively utilise secondary raw materials, pre-concentrates of defined quality are required. Packaging waste streams are treated in waste sorting plants, where different sorting operations are applied. Ballistic separators are frequently used to separate 2D and 3D materials during (pre)conditioning and therefore have a major influence on the overall process performance. Despite their widespread use, until now, few studies have examined how parameter settings affect the performance of ballistic separators. To assess and optimise process performance, we conducted a parameter study on packaging waste using an industrial-scale ballistic separator and near-infrared-based process monitoring. At 22.5 wt% 2D input content, we varied 2D material properties, paddle angle (15°, 17.5°, 20°), rotational speeds ( s 1 – s 5 ) and paddle types (45 mm, closed). All parameters showed significant effects on the process performance. In the material stream used, which contained a proportion of fine material, the 45 mm paddles demonstrated higher separation performance compared to the closed paddles. A specific rotational speed must be reached to achieve an effective separation efficiency. Beyond this, a further increase does not lead to measurable improvements. Two optimisation strategies were developed to determine process optima and enable the integration of the generated results into operational practice. Therefore, the results contribute to the optimisation and potential automation of ballistic separators and the overall improvement of packaging waste sorting plants.

Authors 7

1. Alena Maria Spies corresponding Aachen Chair of Anthropogenic Material Cycles

   RWTH Aachen University

   Affiliation as printed

   Chair of Anthropogenic Material Cycles (ANTS), RWTH Aachen University, Germany

2. Tabea Scherling Aachen Chair of Anthropogenic Material Cycles

   RWTH Aachen University

   Affiliation as printed

   Chair of Anthropogenic Material Cycles (ANTS), RWTH Aachen University, Germany

3. Annika Ludes
   Affiliation as printed

   STADLER Anlagenbau GmbH, Altshausen, Germany

4. Bastian Küppers
   Affiliation as printed

   STADLER Anlagenbau GmbH, Altshausen, Germany

5. Nils Kroell Aachen Chair of Anthropogenic Material Cycles

   RWTH Aachen University

   Affiliation as printed

   Chair of Anthropogenic Material Cycles (ANTS), RWTH Aachen University, Germany

   STADLER Anlagenbau GmbH, Altshausen, Germany

6. Karoline Raulf Aachen Chair of Anthropogenic Material Cycles

   RWTH Aachen University

   Affiliation as printed

   Chair of Anthropogenic Material Cycles (ANTS), RWTH Aachen University, Germany

7. Kathrin Greiff Aachen Chair of Anthropogenic Material Cycles

   RWTH Aachen University

   Affiliation as printed

   Chair of Anthropogenic Material Cycles (ANTS), RWTH Aachen University, Germany