A steel foundry in Switzerland decided to extensively modernize its overhead conveyor blasting machine.
With around 100 employees, Stadler Stahlguss belongs to the Swiss group Stadler Rail, one of the leading suppliers of rail vehicles in Europe. The foundry, based in Biel, generates annual sales of between CHF 24 and 28 million.
60 to 65% of these are for orders for the Stadler Group, says Michael Schmitz, CEO of Stadler Stahlguss.
Other customers come from mechanical and plant engineering for the plastics and food industries, from automotive engineering, energy mechanical engineering and petrochemicals. The framework conditions in Switzerland, a high-wage country, are not easy, so there are just two steel foundries. "We have a unique selling point in terms of component size and tonnage," says Schmitz.
Stadler Stahlguss is said to exist on the international market with a high delivery performance, very demanding cast parts, and high quality. All components pass through the blasting machine. They have unit weights of 3 kg to 10 t.
Stadler Stahlguss recently had the existing blasting machine from an Italian manufacturer modified by AGTOS, the blasting machine manufacturer from Emsdetten, Germany. "The surfaces of the castings were not 100% clean, the scale layers were too firm. This has resulted in high costs for manual regrinding," says Schmitz while explaining the main reason for the modification. In addition, there were long blasting times: "30 minutes was standard, up to 60 minutes for exotic parts," says the CEO. Today it is normally 12 minutes and the outer surfaces are shiny metallic.
Before the modification, AGTOS checked the blasting machine and discussed the project with Stadler Stahlguss. "A first attempt with an AGTOS competitor did not work at all," reports Schmitz. The turbines of the manufacturer from Emsdetten, on the other hand, delivered the best results: According to the discharge angle, the abrasive hits the workpiece surface more precisely. In addition, they are now better positioned. For the modification, AGTOS not only supplied new high-performance turbines including an adapter frame., but abrasive feed and motors were also replaced. In total, the modification only took three days - practically plug and play, whereby Stadler had already dismantled the old turbines.
New turbines increase performance of the blasting machine
The four newly installed turbines are type TA 4.6. The centrifugal wheel has a diameter of 420 mm, as explained by Mario Hintzen, Technical Manager Service at AGTOS. “The engine output remained the same at 18.5 kW. As a result, we didn't have to change much in the electrical system, except to replace the live circuit breakers,” he says. Nevertheless, the performance could be increased by approx. 30 to 35% with the new turbines. A new guide sleeve with a smaller but wider window and the merging of the four turbines create a hotspot with significantly higher intensity when blasting. The discharge speed increases due to the larger centrifugal wheels. "The concentration of the blast was the effect that significantly reduced the blasting time," says Hintzen.
"The basic substance of the blasting machine was still very well preserved, so this modification was justified," he continues. On the one hand, this was due to the fact that large blasting chambers are generally not subject to as much wear as small ones, and on the other hand due to the good maintenance status of the machine. "We chose AGTOS because the overall package was right and the project could be realized in a short time, because it only took a good six weeks from the order to the assembly date. That was not possible with the original manufacturer,” says Schmitz. In addition, it is easier if the communication takes place in such a project in your own language.
Stadler Stahlguss decided against a new machine because there was no space for a new construction in the halls. An interruption of operations - except at scheduled times - was not possible. "With 30% of the cost of a new investment, we now have a machine that is optimal for our purposes and without a significant production downtime."
48282 Emsdetten, Germany