Embracing Digital and Technological Innovation – Tenova

In the era of the so-called Fourth Industrial Revolution, factories have become “smart”, embracing the Digital Transformation. The “steel plant of the future” looks like a place where value is produced through the integration of the enabling technologies of Industry 4.0 into the workplace. For the metals industry, greater connectivity and data sharing will play a significant role in alleviating a number of issues presented by their nature: from remote locations and widespread supply chains, to fluctuating markets and potentially hazardous working environments.

This shift in the business model is triggered by innovative partners like Tenova, which is working with
the aim to make plants always more intelligent and connected, to offer services of high added value by
analyzing the data from machines to optimize production, and to help customers to fulfill their business objectives. In order to obtain these achievements, Tenova has established a partnership with Microsoft, whose goal is to develop a suite of technologies and services thanks to complex architecture enabled through Microsoft Azure cloud platform and algorithms based on machine learning technologies.

Another state-of-the art technology that proves the innovative DNA of the company is Pomini Digital TexturingTM (PDTTM),a long-tested and proven technology developed for surface texturing of rolling
mill work rolls. PDTTM has created new possibilities for designing advanced surface textures to optimize the performance of the work rolls and rolling mills. It also provides a wide range of surface finishes including automotive and tinplate. PDTTMhas several benefits compared to other solutions, which have technological limitations and often require an additional post finishing process. The major benefits arise from the ability to engineer the texture to suit each application in addition to its efficiency and environmental advantages.

The process of Pomini Digital TexturingTM relies on software technology to generate the texture matrix and control the high frequency lasers for texturization.

The Pomini Digital TexturingTM System incorporates an “off the shelf” high frequency laser, which is controlled by the “digital texturing system” developed in Tenova. It guarantees low maintenance and it has been proven in a large number of industrial applications. The Fiber Optic delivery system allows flexible positioning of the texturing head and avoids focus and alignment issues.

Laser technology is a clean and efficient system, and, although it is not a new technology, it is in continuous development. This unique type of high-frequency laser is particularly suitable for software
switching and controlling.

With PDTTM process it is now possible to control accurately and independently many of the surface texture parameters such as roughness, peak count and skew. As a consequence, the quality and performance of both the work roll and the rolled sheet can be optimised. The Pomini Digital TexturingTM process has demonstrated very good results in production; it improves the consistency of the surface texture and achieves quality specifications that would not be possible with other technologies.

The capabilities of the PDTTM process allow the design of surface textures with the aim to meet current specific quality requirements and also to develop entirely new textures to optimize the quality and performance. PDTTM also gives the ability to differentiate products based on the quality parameters of the surface texture.

PolyTEN

The clean, safe and green technology is very efficient and generates a minimum amount of waste. Moreover, the machine has modern design features and minimal hardware components that optimize the design for assembly and manufacturing, with the majority of the technology residing in the control software.

Safety is paramount in the metals industry, with employees often using large machinery or working in
locations that present risks. Industry 4.0 can help safety- relevant information to be spread more quickly and more widely. Devices can be connected via mobile transmission to supervisors and control centers, quick decisions can be made and communicated if necessary.

In the framework of Industry 4.0 technologies, industrial robots in the workplace are an opportunity
to improve the level of safety. In this context, the important collaboration with Polytec Robotics – worldwide leader in robotics solutions for the metals industry, brand of BM S.p.A – represent an important step along the path of innovation. Tenova has recently signed an agreement for
the implementation and sale of robotics solutions for steel plants, called PolyTEN collection, with
the aim to improve the safety level on the workplace and reduce the length of the productive cycle.

Within the PolyTEN collection, PolyEye Beesafe is a state-of-the- art anthropomorphic robot – part of
Tenova technological platform called “No Man on the Floor” – which was designed to enable the full operation of the furnace without workers on the field. PolyEye Beesafe makes possible to view the inside of the furnace and conduct a thorough inspection to identify potential malfunctions and facilitate predictive maintenance interventions. Predictive maintenance is thus possible and safety is enhanced.

Being Sustainability a key commitment for Tenova, most innovative technologies are designed to combine the need to meet the customers’ productivity goals with the objective to reduce resources depletion. Steelmaking industries are always more keen to enhance the level of environmental sustainability of their productive processes, and, in some cases, the regulatory framework has evolved
so to accelerate this trend.

An example is China, where the government has strongly promoted the reduction rate of CO2 emissions in metal making. As a consequent, the Chinese steelmakers are starting to increase the share of electrical steelmaking in comparison to Blast Furnace (BF) or Basic Oxygen Furnace (BOF).This trend stimulated the interest in Tenova EAF Consteel® Evolution. Over the last year, Tenova has been awarded important contracts for a total of eleven Electrical Arc Furnaces (EAF) Consteel® Evolution in
China.

Pomini Digital Texturing

The Consteel®system (and its improved EAF Consteel® Evolution) is currently the most referenced system that continuously feeds and pre-heats the metallic charge (scrap, pig iron, etc.) to the EAF. The continuous charging process is normally used by electric arc furnaces processing large amounts of DRI or HBI, since batch processing (top charging by buckets) of these material has proven to be unworkable; Consteel® has extended this approach to the processing of scrap and pig iron achieving the ultimate in charge flexibility and environmental friendliness.

The Consteel® achieves the continuous feeding of scrap by means of an inertial conveyor, which moves the scrap from an open section, used for charging (usually by crane), to the furnace, passing through a closed section in which scrap is being heated by process off-gas travelling in the opposite direction, towards the fume extraction system (FES).

The Consteel® system can use any type of steel scrap: any metallic raw material that can be charged in a traditional electric arc furnace can be used in a Consteel® system as well. In terms of maximum scrap dimensions, the normal limits specified by the European Steel Scrap Specification (i.e. 1.5×0.5×0.5m) are fully compatible with Consteel® operations.

The great operational flexibility of the Consteel® process is owed to the generalized continuous charging
approach, but there are several other advantages compared with the traditional EAF. Since Consteel®
processes any charge material with a controlled continuous feeding on a flat bath, under foaming slag, the use of the available time and electric power is optimized, with the least possible disturbance of the electrical network (less harmonics and flicker).This has allowed avoiding the installation of a SVC unit in
several cases, and the acoustic emissions of the process are also reduced for the same reason.

The metallic charge heating achieved inside the Consteel® system allows a significant reduction in electric energy consumption, ranging from around 40 kWh/tls in old Consteel® units to around 70
kWh/tls for the future Consteel® EvolutionTM units. A better metallic charge yield is one of the Consteel® benefits that became apparent only after its wide industrial application: it has been found that switching from a classic bucket charged furnace to Consteel® furnace usually results in about 1% yield improvement. This can be explained with dust recovery inside the heating tunnel and with a lower charge oxidation owed to a more distributed decarburization.

The distributed decarburization of the charge along the whole active time also means a more stable emission of process off-gas, allowing the optimum sizing of the primary fume extraction plant, proving the optimal condition for a further heat recovery system such as Tenova’s iRecovery package.

The controlled and distributed emission of process fumes has also been found to be able to minimize the
emission of pollutants possibly released during the processing of scrap. This offers the most convenient
condition for the compliance with the increasingly stricter environmental regulations. The continuous process carried out in the Consteel® also reduces the mechanical stress of the whole equipment significantly, resulting in an overall maintenance saving compared with the equivalent bucket-charged furnace.