Aging with grace
In order to modernize its aging stretch-bend-leveling lines, a prominent sheet copper manufacturer in the US chose to rely on the services of the Solution Partner DAA Delta Technik. The company wanted to have the plant completely retrofitted over Christmas – which it was.
Sheet metal is used in mechanical engineering, for car bodies, and in electrical engineering. Thereby, uniform material strength and smooth surfaces are always of a high, if not the highest, priority. To achieve and to optimize these material properties, the rolled sheet metal is stretched and leveled in what are referred to as stretch-bend-leveling lines. Based in Remchingen, Germany, Burghardt + Schmidt is a leading global manufacturer of such plants. Its automation partner, DAA Delta Technik, is a long-time Siemens Solution Partner specialized in SIMATIC and SINAMICS automation projects – both the implementation of new plants as well as retrofits of older ones.
Retrofits during ongoing production
“In addition to new systems, the number of retrofitting jobs is increasing as well,” Jan van den Broek, managing director at DAA Delta Technik, points out. Although machines built in the 1980s are quite robust mechanically, replacement parts are no longer available, plant documentation is often incomplete, and source codes are also missing. “Since those machines are key machines, there is an acute need for action to maintain and optimize production,” van den Broek explains. In cooperation with Burghardt + Schmidt, DAA Delta Technik has successfully implemented many retrofitting projects all over the world. The US client urgently needed more flexibility for the implementation of customer demands and wished for improved plant usability. “We accepted the challenge – also because we knew that Siemens would be able to help us out on-site if needed,” Peter Voß, sales engineer at DAA Delta Technik, comments.
Centralized control and regulation intelligence
The plant in the United States is powered by direct current drives. Existing converters were replaced by the new SINAMICS DCM converters. Two SIMATIC S5 135 U units and a SIMADYN D drive control system were previously used for control purposes. Special proportional valve control cards of the hydraulic supplier, integrated into SIMATIC S5, controlled the roller leveling supports.
The new concept is based on SIMATIC S7-400 with an integrated FM 458-1 DP. This freely programmable application component carries out the complex control tasks of the eleven main drives linked to the system via PROFIBUS DP. Proportional valves were connected to the control system via a SIMATIC ET 200S distributed I/O system. Thus, the control and regulation are combined in one central S7-400 rack. “We prefer concentrating the intelligence in a single place to be able to identify possible errors quickly and to transfer the memory card with the program onto a new module. An important advantage of the FM458-1 DP is the possibility of intellectual property protection. The modules are interconnected via CFC and can be locked, which protects our know-how and offers the operator the security that no undesired changes will be made to the program,” Voß adds.
Exceeding every demand – without delays
The plant is now visualized with SIMATIC WinCC, and the new operator panels are equipped with SIMATIC push-button panels. The openness of this solution increases the flexibility and improves plant usability. Helmut Mau, project engineer at DAA Delta Technik responsible for planning and also managing the retrofit, has fond memories of the client’s pleased inspection: “The customer could no longer recall the machine’s precise capabilities. As a precaution, the machine had not been run at maximum speed for a long time. Now, it achieves 200 m/min again – and at a higher quality.” Now the machine can be quickly, easily and precisely adjusted for every job. The leveling results have been significantly improved. As a result, customer requirements were more than met – without any delays.
For van den Broek, the uniqueness of the solution lies in the integrated engineering: “Not only the control and visualization work together perfectly. The SINAMICS converters are integrated to enable parameterization and diagnosis with STEP
7 – also remote diagnosis from anywhere in Germany, if necessary.”
Drive solutions with energy savings potential
DAA Delta Technik is also equipping new plants from Burghardt + Schmidt with the same automation and drive components, although with three-phase alternating current systems. “Here we are using energy recovery and brake energy in the intermediate circuit of the drive line-up,” Voß comments. “The recovered energy can be used directly in the plant. Because half of the drives are operating in generator mode, the required power input is virtually also cut in half. With SINAMICS S120 and DCM we are flexible. We can modify both new plants with alternating current systems as well as plants with the proven direct current technology to ensure reliable operation for many years to come.”