Düsseldorf, December 08, 2017

Modernization based on concept engineering

Concept engineering has turned out to be an efficient tool to develop the best solution for a customized plant modernization through a holistic approach. The Finnish company Outokumpu, for example, is continuously improving the competitiveness of its hot rolling mill in Tornio with the aid of concept engineering.

To meet the increasing market demands in terms of quality, productivity, operating costs and product portfolio, every plant must be upgraded at regular intervals in the course of its lifetime. Accordingly, the requirements to be satisfied by the equipment manufacturer are often growing along with the plant life and the specialization in the product range.  

Holistic analysis

To cope with the customers‘ demand for complex modernizations and a continuous improvement  in performance, SMS group developed concept engineering. This means a systematic analysis of a plant on the basis of which SMS develops, jointly with the customer, the optimum technical and economically efficient solution. The examination further includes items like plant technology, production process and maintenance. Process technology, mechanical and hydraulic equipment, electrical and automation systems are considered in the overall context also taking into account such aspects as consumption figures, safety and environmental standards. The tools SMS uses to prepare such all-round analysis comprise the entire range of state-of-the-art methods like FEM or CFD analyses or simulation programs. It is absolutely vital here that customer and equipment supplier cooperate very closely and they respect their partner’s know-how and operating results.

Concept engineering provides coordinated measures for maintenance, plant engineering and production technology. Hence, the customer is given a comprehensive and detailed basis for his future planning at a comparatively low investment.

Outokumpu in Tornio

One example of a successful application of this approach is the concept engineering for the hot rolling mill of Outokumpu, a market and technology leader in stainless steels. The company’s rolling mill in Tornio, Finland, comprising one reversing rougher, a Steckel mill stand and a coiler, was commissioned in 1987. To increase production, SMS group extended the facility by three finishing stands and one coiler within a sensational modernization project in 2005.

After the revamp had been completed, the close cooperation of the two companies was continued within the frame of a cooperation agreement. This liaison has led to concept engineering on the basis of which Outokumpu pursued the following objectives:    

  • Improve product quality
  • Enhance plant availability
  • Expand the product portfolio
  • Simplify maintenance and spare parts management
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Enhancement of plant availibility

The measures to be taken for the enhancement of plant availability were developed on the basis of a detailed investigation of the unexpected plant downtimes over a period of more than two and a half years. In the course of these studies, particularly vulnerable areas were identified and the measures in the fields of maintenance and plant engineering defined accordingly.

Pass schedules for new products

Over the last few years, Outokumpu has been continuously expanding its product portfolio to even better meet the demands of its customers for new steel grades and dimensions. SMS supported Outokumpu in the development of these new products and of the design criteria of its facility.

Simultaneously, the production process was analyzed in detail. By adapting the profile and flatness control, modifying the CVC® contour of the work rolls and changing the strip tensions it was possible to significantly improve the rolling stability and to reduce output losses by up to 80 percent.

Rolling mill modernization

Outkumpu’s further objectives were to produce strips of higher maximum strength and to improve the surface quality. For this purpose, concept engineering was used to develop targeted modernization measures for step-by-step implementation.

In 2016, SMS group installed a new descaler including descaling valve and new pumps. Like the old one, the new descaler operates at a pressure of 180 bars, but, thanks to its improved design, will have a better surface cleaning effect.

The Steckel mill stand was equipped with new Sieflex® HT gear-type self-aligning spindles to transmit the higher rolling torques needed for the production of high-strength steel grades. New wheel sets for the mill pinion gear unit have already been supplied by SMS group. In addition, new bending blocks were installed in the Steckel mill stand, which are less susceptible to failure and easier to change.