Steel bars are used in many industries. The big variety of applications requires just as many options and the best qualities. This also affects the requirements for the surfaces. Innovative concepts are therefore asked for in this area.
The great competence in technology and production turned the Stahlwerk Annahütte Max Aicher GmbH & Co. KG into a leading and powerful company in the bar and thread steels segment. SAH steel bar products have proven themselves worldwide in the automotive, tool and chain industries, in machine and plant construction, in agricultural technology and in energy generation.
In the field of technical engineering, the company is the world market leader for hot-rolled threaded steel with products from the SAS Systems brand. SAS threaded steel systems connect, clad and anchor and are used in major structural engineering projects. No matter whether in building, civil engineering, bridges, roads, tunnels or mining.
A new shot blasting machine (type DR 80) supplied by the manufacturer AGTOS was put into operation for descaling steel bars.
After the decision for a new blasting machine had been made, the requirements were defined by Annahütte. Andreas Kammermeier, Assistant to the Management: “The new blasting system had to be integrated into our existing production line. During installation, it was important to us that the interface transitions fit. Both worked out brilliantly. "
"The challenge is that the entire rod has to be blasted evenly, i.e. the entire surface of the rod must be freed from scale. Our old system was equipped with 3 turbines, which resulted in poor angle coverage. It happened that we had to blast material twice in order to remove the scale from the entire rod surface. The new system has 4 high performance turbines and thus the angle overlap is given at all times. This means that an optimal blasting result can always be achieved even at higher throughput speeds. This was not possible before, ”said Kammermeier.
After the steel bars have been delivered, they are straightened and bundled into the inlet of the blasting machine. There, they are separated and run through the blasting system on rollers. The support table has a capacity of 7 tonnes, and round bars from 12-40 mm are currently being processed. Due to the high performance of the machine, all types can be descaled at a speed of 1 m / sec. The blasting process is followed by annealing and sawing before the steel is loaded.
Reliable blasting technology
The blasting machine is designed for steel bars with an outside diameter of 10-80 mm. The aim of the blasting is a purity level of B Sa 2.5. After the start of the roller table, the workpieces actuate the switching threshold located in front of the blasting machine's inlet lock. This triggers the automatic supply of abrasive to the running high-performance turbines. So blasting only takes place when workpieces are in the blasting area. This procedure prevents additional wear in the blasting system and is gentle on the abrasive. The bars are transported through the system by three transport rollers arranged in relation to the conveying direction. The high-performance turbines descale the workpieces from the outside evenly over the entire surface.
The blasting chamber is protected by easily replaceable wear plates. The inlet and outlet sluices of the blasting system are equipped with rubber slats to seal against the escape of abrasive. Generously dimensioned doors are provided in the blasting chamber housing for maintenance purposes.
The abrasive is kept in circulation for continuous use and optimal cleaning. The cleaned abrasive reaches the high-performance turbines from the abrasive bunker via the abrasive control unit.
A fan generates the negative pressure required to remove dust from the blasting system. The extracted air is cleaned with an AGTOS cartridge filter system.
A suitable maintenance platform is installed for maintenance and adjustment work on the bucket elevator and the abrasive preparation.
The AGTOS high-performance turbines have a drive power of 22.0 KW each. Frequency converters enable the machining of the workpieces with different programs. The customer Annahütte currently uses one program for all requirements. A remote maintenance option using VPN has been set up, so this means that AGTOS technicians can react quickly to customer questions. To reduce the sound pressure level of the measuring surface to below 80 dB (A), a complete housing was installed for the system.
Selection of the blasting machine manufacturer
“AGTOS has a very good reputation in the industry and the quality of the systems is well known there. Furthermore, we felt very well and competently advised. During the technical clarifications, the overall concept of the blasting system, noise protection and filter system convinced us. Various details such as the design of the wheels or the lining of the blasting chamber naturally also contributed to our decision”, says Andreas Kammermeier.
48282 Emsdetten, Germany