Swiss Steel invests in a new furnace transformer

by David Fleschen

Swiss Steel, one of the leading suppliers of quality, stainless steel and free-cutting steel solutions and part of the SCHMOLZ + BICKENBACH Group, is investing in the future. Today, a new furnace transformer has been delivered which enables an increase in production, which sustainably strengthens first-class positioning in the market and the location in central Switzerland.

In the electric arc furnace steel scrap is liquefied by means of electrodes. Immediately adjacent to the furnace is the furnace transformer (transformer), an oil-cooled high-performance transformer that provides the necessary voltage for the electrodes within a certain power range. The transformer from Swiss Steel has been in operation for around 20 years and has a high load due to the high annual production and the short downtimes.

The state of the transformer is continuously monitored by regular dielectric / chemical and decomposition gas analyzes of the transformer oil. At high temperatures, decomposition gases are produced, which are reflected in the gas content of the oil. If this happens, damages have already occurred in the transformer whose escalation can only be prevented by a timely shutdown of the system and thus the temporary cessation of production.

With the new transformer, Swiss Steel upgrades its plant to state-of-the-art technology and increases its production potential by around 10%. The improved efficiency of the transformer and more efficient electrode control accelerate the melting process and reduce the waiting time at the downstream casting plant. In addition to improved efficiency and increased production, Swiss Steel also minimizes the risk of default. Investing in a new transformer will enable us to reliably produce high-quality products for our customers in the future as well.

In order to guarantee an efficient melting process, the new transformer must be compatible with the structural and technical conditions on site and also provide precisely defined output quantities. The project was tendered out and Tamini, a leading manufacturer of high-performance transformers from Italy specializing in transformers for metallurgical smelting processes, was awarded the contract. The transformer has a rated output of 105 MVA, weighs 132 tons and has proud dimensions of 5.6 x 7.3 x 4.5m. Together with an external throttle, weighing 38 tonnes, 4.8 x 4 x 3.9m, the new transformer was driven by special transport over 330 km from the Tamini factory in Ospitaletto to Emmenbrücke. For this purpose, the Gotthard tunnel was blocked in both directions during the night on 4 July for one hour.

The new transformer will be installed as part of the annual maintenance and will be ready for production from mid-August.

This is not the only investment at Swiss Steel: With the construction of a new walking beam furnace and a new Garrett line, Swiss Steel will have one of the most modern systems in the world. The new walking beam furnace upstream of the rolling line will make it possible to bring the billets produced in the steelworks faster and with optimal through-heating to the temperatures required for further processing. In addition to an increase in performance, quality losses are simultaneously reduced and substantial energy and CO2 savings achieved. The new Garrett reels downstream of the rolling line for winding the rolled products allow the ring weight to be increased to over 2.2 tonnes from the previous 1.8 tonnes. With this, Swiss Steel meets the requirements of its customers. The commissioning of the plants is planned in stages. The walking beam furnace is expected to go into operation in late 2019, Garrett reels already a few months earlier. Full operation of the plant is expected by the end of 2020.

Swiss Steel is also investing in environmental protection: in cooperation with EWL, the excess waste heat from the rolling mill is fed into the district heating network. By using this waste heat, the CO2 emissions of district heating end customers are reduced by 1,500 t per year. This is a measure implemented by Swiss Steel as part of the target agreements with the federal government on energy efficiency and CO2 emissions. The system is now connected.
Source: Swiss Steel, Photo: Fotolia

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