At Recon Services Inc. in Austin, Texas, Walter Biel runs a sorting line for mixed C&D waste. Recently he added two new workers – the computerized sorting robots Wall-E and Rob.
In 2015 Walter Biel decided to revamp his facility: Material enters the system from a hopper, gets screened by a 2-deck screener, and everything that isn’t wood gets sorted out by people in sorting cabins. The wood gets high-speed chipped into fuel.
That same year robots from Plexus – ZenRobotics’ US sales partner and sister company of Komptech Americas – caught Walter’s attention. He decided to buy a unit with two robot arms. The AIpowered robots were set up in existing sorting cabins, and nicknamed Wall-E and Rob.
The two robots worked well – so well that they got bored, since the material feed wasn’t up to par. The bots sort out high-value or highly problematic fractions by using various measurement methods. However, since the material stream was screened only with a two-deck screener, fines and 2D material would get on the conveyor along with the wood. Another problem was stoppages in the deck screener, which meant that the sorting conveyor sometimes ran empty.
Only a modification of the processing line could increase the efficiency of the robots. This is where the Komptech Americas and Plexus treatment experts together with the project office in Vienna reconfigured the Recon Services plant with the condition that the existing machines and conveyors had to be used and two- and three-dimensional pieces had to be pre shredded and separated before the two-dimensional got to Wall-E and Rob. To bridge the gap short-term, Komptech Americas supplied a low-speed shredder on loan immediately.
Terminator & Ballistor
The new plant configuration uses the Terminator 5000S as a preshredder. In addition to being tough and wear-resistant, the Terminator stands out because of its ability to deal with contraries. Its armoured drum was fitted with F teeth, and the counter comb got armoured teeth. To ensure problem-free operation the machine was configured for high clearance. The distance between the bottom of the drum and the top of the conveyor is a metre.
For separating out fines and flats, only the Ballistor 10300 ballistic separator came into consideration, which separates three fractions in one pass. Since the material contains abrasives, the replaceable side and screen elements on the paddles of the separator are of hardox, while the wear elements on the sidewalls are of special S690 steel. A vibrator feed channel at 45 degrees distributes the material stream across the entire working width of the Ballistor.
The new processing layout
Green: Supplied by Komptech Americas
Red: Existing conveyors
Grey: New conveyors
Blue: Existing machinery
The two-dimensional fraction from the Ballistor is manually sorted. The fines are screened again with the existing deck screen. The resulting fines are taken away for use as landfill cover, while the middle fraction is sent through the existing windsifter. The goal is to get the wood out of this middle fraction.
Ferrous items in the three-dimensional material are magnetseparated and sent to two walking floor hoppers. The throughput of the line is higher than Wall-E and Rob’s, so processing is done in one shift and sorting in three. Wall-E and Rob only see cubic items, and remove everything except wood. With the controlled hopper feed and triple re-spreading of the material before the ZenRobotics recognition unit, the robots don’t get too many surprises. Nothing is covered up, there is enough time to set the conveyor speed, and most importantly, work can continue around the clock. For this new processing line setup, Walter Biel and Recon Services were awarded the title of “2018 Recycler of the Year” by the American Construction & Demolition Recycling Association.