ENGINEERING
AND METHODS
Every single stirrer design derives from the quality and production exigencies of steel producers. On the back of each project, there is a very deep and detailed metallurgical and defectiveness analysis regarding the final product employment. Such analysis leads to the selection of the best stirring technology.
To determine the best stirring system it is necessary to study the liquid steel motions imposed by the stirrer. ergolines has developed a powerful designing tool that allows foreseeing and therefore optimizing the stirring process within various situations. The tool, internally developed by ergolines researchers, divides the designing in two phases, an electromagnetic and a fluid dynamic calculation coupled by an algorithm allowing it’s use within the dynamic design ambient.
Electromagnetic task
In the electromagnetic calculations EMS geometrical dimensions, mould and cast product shielding effect are considered. It provides:
- EMS Current Range
- EMS Frequency Range
- Best wave shape for the application Equivalent
- EMS electrical circuit
- Power supply design parameters
- Electromagnetic forces
Fluid dynamic task
In the fluid dynamic calculation, the shroud geometry and the casting speed influence are analyzed. It allows to:
- To analyze flow pattern inside the mould
- To determine the best EMS working current
- To determine the best EMS working frequency
- To analyze the meniscus velocities in order to avoid powder entrapments
- To analyze flow pattern induced by S-EMS/ F-EMS to avoid white bands
- To determine the best stirrer position (both in mould and in final position)
From the above, it may be easily understood that all ergolines EMS designs are turn-key solutions where metallurgical results are at their best, efficiency is very high, reducing energy consumption (kW / ton of produced steel), and therefore the customer returns on investment.
In addition, ergolines guarantees experimental validation of the design methods by intensive sessions of factory testing.
Taylor made approach
Analysis
The main target is to minimize the impact on the available spaces, through maximizing the electromagnetic stirring performance so as to guarantee and fulfil the metallurgical expectations of the customer’s steelmaking specialists: improved equiaxial growth, minimized carbon segregation, lower inclusion, elimination of pinholes and blowholes, lower centre porosity, better heat transfer, crack reduction and an overall enhanced surface quality.
Design
The mechanical design is supported by the most modern CAD/CAE technologies for the development of the stirrer bodies and the verification of the installations and the interfaces with the continuous casting machine. Using tri dimensional models allows ergolines a quick and secure information exchange with the customer and grants a complete vision of the stirrer installation.
Such instruments allow an accurate structural calculation for the verification of the stresses acting on the stirrer due to the pressures of the cooling circuits and thermo- dilatations due to the radiation of the cast product.
Manufacturing
The activity of ergolines is not limited to engineering: all material procurement and production steps are directly and carefully followed in the ergolines production facility. All aspects of production must be accurately managed: screening and choice of materials, selection and qualification of suppliers, constant updating of manufacturing technologies and processes, including chemical and thermal treatments, as well as a particular care for the specialization and training of machine operators.
High, reliable and long-lasting insulation properties are given by a special insulation technique and by a special proprietary resin treatment based on VPI (Vacuum Pressure- Impregnation) technology, which ensures a long coils lifetime. All manufactured products are visually and instrumentally checked and tested during all manufacturing phases.
Quality
The first quality control applied to ergolines products, is a very attentive selection of the suppliers and the purchase of certified products. Such activity, together with a further control with dedicated instruments, are granting the top trustworthiness standards of the purchased materials.
The second control is strictly connected with the production process, ruled in every phase by strict internal procedures. The last testing phase allows the final marking and grants the customer a product of top performance and trustworthiness, life span.
Some references
Valbruna
Venete spa
Mittal
Edelstahl
Group
Edelstahlwerke
Group
Sa
Company
Casting Technologies Gmbh
AB
Group
Steel