Primetals to modernize drive system on the hot strip mill of tk Hohenlimburg
by Hans Diederichs
Higher performance for future products
thyssenkrupp Hohenlimburg GmbH has awarded Primetals Technologies an order to convert the existing cycloconverter drive systems to medium-voltage drive systems on stands 7 and 9 of its medium-wide hot strip mill in Hohenlimburg, Germany. The aims of the project are to replace the existing cycloconverter drive system while also increasing performance for future products. This was preceded by a joint analysis of the complete plant and a calculation to minimize the drive power actually required in order to optimize the investment budget. The scope of supply by Primetals Technologies covers the complete electrical conversion of the drive trains from the transformer through the medium-voltage converter to the drive motor. The order also includes the integration of the new drive system into the existing basic automation of the medium strip mill. The project is scheduled for completion in December 2021.A working group from thyssenkrupp Hohenlimburg and Primetals Technologies, comprising hot-rolling experts, rolling technologists and drive specialists, compared the motor specifications with the existing pass schedule specifications. The results of the calculations for drive dimensioning were jointly verified. This enabled the motor powers and torques previously specified to roll the complete portfolio of products to be reduced. This was not the only saving on investment: the possibility of using existing spare parts –such as motors and transformers – with the drive system supplied by Primetals Technologies was also examined jointly with thyssenkrupp Hohenlimburg. This resulted in a further saving on investment, producing a total saving in the six-figure euro range. The solutions developed in this project can also be applied to future drive modernizations. thyssenkrupp Hohenlimburg GmbH is based in Hagen, Westphalia. It has had a reputation for expertise in the processing of hot-rolled Hohenlimburger medium-wide strip for more than 150 years. Nowadays, this strip is marketed under the brand name of precidur, a steel product with a high technical standard that meets individual customer requirements. precidur is used as an input material in the cold-rolling industry and in direct processing such as that used in the automotive supply industry. The medium-wide hot strip mill is continually modernized. Its processes are completely automated to provide the best conditions for the optimal setting of technological properties and the narrowest of tolerances.
Source and photo: Primetals Technologies