ABB LTD Zurich, Switzerland, May 9th, 2016 -- New generation of electromagnetic stirrer improves electric arc furnace operation at Outokumpu Stainless AB in Avesta, Sweden.
A global leader in stainless steel and high performance alloys, Outokumpu's stainless steel foundry in Avesta, Sweden is one of the world's most productive. Boasting a fully integrated two meter wide mill with 700 employees, they specialize in the production of steel grades with a high chromium content. However, the addition of ferro-chromium in the arc furnace process, necessary to produce these particular steel grades does have disadvantages. With a higher melting point than the surrounding melt, the ferrochromium can settle on the furnace bottom to form skulls. At Outokumpu, this led to variations in tapping weight, higher electrode and energy consumption and even practical difficulties when charging the scrap baskets, all of which had a negative impact on productivity.
The solution
Outokumpu chose ArcSave®, the new generation of electromagnetic stirrer (EMS) to optimize the performance of their electric arc furnace operation (EAF). A specific stirring profile, controlling stirring intensity, duration and direction, was created to focus ArcSave's improved stirring power on Outokumpu's desired process improvements, including enhanced scrap and ferrochromium melting, reduced costs and improved productivity.
In the summer of 2014, an ArcSave was delivered to Outokumpu Stainless AB for installation on their 90 ton arc furnace. A new lower furnace shell made from nonmagnetic stainless steel was fitted and, to exploit the full potential of ArcSave, a new temperature robot was also installed. Wherever possible, equipment was pre-assembled and tested before delivery, and preparatory work including installation took place during available down times.
The results
In line with Outokumpu's objectives, ArcSave has delivered improvements which contribute to a more stabilized arc, more homogeneous steel bath, enhanced slag-metal reaction, more consistent EAF tapping conditions and argon oxygen decarburization (AOD) operation. This provides both metallurgical quality and financial benefits, and a smoother and more reliable process.
'We managed to solve our furnace bottom skull problem using ArcSave®,' said Pär Ljungqvist, EAF Process Developer at Outokumpu Stainless . 'The result is smoother, more predictable EAF operations at lower cost.''
The chart below shows average savings comparing results from three months before and three months after installation:
Total electrical energy consumption -3 to 4%
Electrode consumption -8 to 10%
Power-on time -4 to 5%
Tap temperature hit ratio 100%
Tap temperature reduction -20 to 30C
Tap weight hit ratio +24% (reached 93%)
N consumption -70%
About Electromagnetic stirring from ABB
Steel and aluminum industry customers have chosen ABB's noncontact EMS technology for over 1200 installations worldwide; ABB invented and continuously develops this technology to ensure that customers get long-term, significant results from its use. ABB's wide and versatile range of EMS products provides solutions that can be customized to specific process needs to deliver maximum process improvements.
With EMS, effective stirring is achieved when the magnetic field from the static induction coil, placed on the outside of the furnace, interacts with the electrically conducting metal bath. EMS effectively reduces elevated surface temperatures and eliminates hot-spots in the melt. This, coupled with minimized oxidation in the melt surface, significantly improves heat transfer to the melt leading to increased productivity, a safer working environment and a more reliable process.
Since ABB's EMS products provide stirring in the entire bath, customers achieve even more uniform chemical analysis using ArcSave. In addition to electromagnetic equipment, ABB offers comprehensive performance solutions for metals industry customers. Learn more at http://new.abb.com/metals
About ABB
ABB (www.abb.com) is a leading global technology company in power and automation that enables utility, industry, and transport & infrastructure customers to improve their performance while lowering environmental impact. The ABB Group of companies operates in roughly 100 countries and employs about 135,000 people.
ABB Ltd. published this content on 10 May 2016 and is solely responsible for the information contained herein.
Distributed by Public, unedited and unaltered, on 11 May 2016 07:27:09 UTC.
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