The starscreens from Backers are deployed in the screening of minerals and organic materials, where 80 % of the starscreens are wheel-mounted, track-mounted or used in both ways. The ascending starscreen technology provides advantages with regard to the intensity, in particular in connection with air separation and/or magnetic separators. The feed material often contains large and heavy chunks (in the case of concrete, e.g. from 20-30 kg), which should be sorted out in advance. In the case of cohesive material, bar grates and even vibro-grids will quickly reach their limits.
In 2016, Backers developed the new “grizzlyscreen” in order to expand the application range of the starscreen. Its rotating tubes operate continuously and with good throughput even with cohesive materials. The rotation enables working with a smaller separation cut than it would be possible e.g. with a vibro or a bar grate. Another advantage: agglomerates and softer materials will be crushed by means of rotation.
The hook-lift mobile starscreen 2-hta was the first starscreen to be equipped with the new grizzlyscreen (Fig. 1). The compactly structured starscreen ensures an even better use on construction sites and in the recycling industry. The grizzlyscreen improves throughput, cleaning effect and service life of the starscreen and enhances other factors as well. Due to the strong rotary tube bearing, larger chunks (with a weight of up to 300 kg) may be contained in the feed material (heavy parts should be sorted out in advance by means of an excavator). The oversized parts are separated by the grizzlyscreen. The inclined position of the grizzlyscreen is hydraulically adjustable, accordingly, the residence time of the feed material as well as the intensity of the grizzlyscreen vary.
The second grizzlyscreen has been practically tested since July. Characterized by its open sides, it is mounted on the bin of starscreen 2-tb17 (Fig. 2). With 8 rotating tubes, it has a feeding width of 2.3 m and provides a capacity of up to 300 t/h when filled by means of an excavator. In autumn 2016, the first grizzlyscreen with 12 rotation tubes on the starscreen 2-ta will be deployed. It brushes the coarse material aside and can be filled by excavator or by wheel-loader.