Schulte Strathaus wins competition for best scraper

There were no preconditions. Each competitor could choose a belt. The winner would be the one whose scraper returned the best cleaning results. The measuring method in each case was identical. A second scraper covering only a small section of the 120 centimetre wide belt was mounted behind each scraper. “Then we hung a bucket underneath and after ten minutes removed it and weighed the contents”, explained Afatek project manager Henrik Juul Rysgaard. The result was easy to calculate on an hourly, daily and weekly basis, he added. Only secondary belt scrapers were tested.

Afatek is a recycling company that processes slag. 235 000 tons are processed annually at the firms headquarters in Copenhagen harbour. Waste in Denmark is sorted in various fractions. Even after sorting and incineration, valuable residue can be found in the residual slag. And that is exactly what Afatek salvages. The plant with 52 conveyor belts is housed in a 70 metre long, 30 metre wide  and, at its highest point, 11 metre high tent. And in there, says Rysgaard, “it has to be clean”. Unfortunately, that was not the case with the newly delivered conveying system. “We were not happy with the scrapers.

We wanted equipment which met our demands. And we organised the competition to find it.” Afatek process slag with different humidity. That is a challenge for scrapers. The  test took place with moisty and drier material.

German manufacturer Schulte Strathaus came out as the winner. Compared to the other competitors, the differences were enormous. In the test with drier material, residue could be reduced by more than fourfold compared to the runnerup. Whereas Schulte Strathaus recorded an hourly average of just 3,15 kilograms, the next best was 12,6 kilograms. Third place resulted in 13,61 kilograms and 51 kilograms were measured for the fifth and final competitor. The test with moist material produced similar results. Here Schulte Strathaus again took first place with only 6,75 kilograms, while second place turned in 19,54 kilograms. 21,38 kilograms were measured for third place and 42,9 kilograms for the fifth and final place.

Rysgaard gave two reasons for Schulte Strathaus outstanding performance in comparison with the other competitors. Firstly, the German manufacturer chose the belt with the widest variety of material, with granulation ranging from 0 to 50 millimetres. The other competitors chose belts with finer material. But he considers the segmented pressure roller system employed by Schulte Strathaus to be the main reason for their excellent results. This ensures that the metal carbide strip is always correctly aligned to the belt. Rysgaard: “This pressure roller system is a very good solution particularly when belt tension varies, as in our case.” And that is why, continued the project manager, “Schulte Strathaus won the competition.” – Now Afatek wants to retrofit the German manufacturer’s Starclean scrapers where ever it makes sence and is possible.