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Conferences / trade shows
October 1-2, 2009
Annual meeting of Association of International Roll Pass Designers and Rolling Mill Engineers (AIKW),
A Coruna, Spain.
Joachim von Schéele, Linde: Experiences from Over 100 Oxyfuel Installations at Rolling Mills: Higher Throughput, Large Energy Savings, Less Environmental Impact and Improved Quality
AIKW's web site
October 18-21, 2009
Galvanizers Association's 101st Conference, Louisville (KY), USA
Wolfgang Püttgen, SMS Siemag: New Strip Processing Line Design by Use of Direct Flame Impingement (DFI) Oxyfuel Technology for Strip Heating and Cleaning
Galvanizers Association's web site
November 2-3
International Tube Association's "Pipe & Tube 09" conference, Istanbul, Turkey.
Joachim von Schéele, Linde: Substantially Improved Reheating Using Flameless Oxyfuel
Pipe & Tube 09 web site
Press releases
POSCO orders REBOX DFI for continuous annealing line at Pohang
Linde POSCO press release (PDF 135 KB)
Dongbei orders world's first REBOX® DST for stainless steel wire annealing
Dongbei press release (PDF 78 KB)
Excellent results from flameless oxyfuel reheating at ArcelorMittal Shelby
AM Shelby (PDF 72 KB)
Turnkey flameless oxyfuel rotary hearth furnace to Ovako, 3rd at same site
Ovako RHF (PDF 61 KB)
Walking beam furnace at SSAB has reached highest ever heating capacity
At SSAB’s mill at Borlänge, Sweden, slabs are reheated in two 37 meter long by 12 meter wide walking beam furnaces (300 tonnes/hour per furnace), from 20°C to 1,230°C. The air-fuel combustion system uses a recuperation system to preheat air to 400°C. The fuel (oil is used) consumption is 440 kWh/t (1.58 GJ/t).
In February 2009 a REBOX® HLL solution was installed. It creates a type of flameless oxyfuel without replacing the existing air-fuel burners. By reducing the air flow and substituting high velocity oxygen injection into the combustion, great benefits can be achieved. 75% of the oxygen needed for the combustion is supplied with this technique. The flue-gas volume is less than 25% that of air-fuel. The system start-up took only one day. The installation in only one zone has increased the heating capacity from 300 to 320 tonnes/hour.
The installation is rather easy because it does not include any replacement of burners or installation of additional burners, which minimizes the installation down time. The air-fuel system can at any time be brought back into operation as is was before. This eliminates any potential risk relating to the implemention, and it enables operation to be flexible and optimized in response to fluctuating fuel cost and production requirements.
Some important results from this flameless oxyfuel installation:
- No negative impact on the surface quality.
- A positive impact on the temperature uniformity of the slabs.
- The ideal heating curve suggested by the control system can be achieved more easily.
- Less smoke emanating from the furnace, greatly improving the plant environment.
Based on the results of current installation in one zone, a full implementation would provide:
- A reduction of NOX emission by 45% (-14% by one zone).
- Fuel consumption can be decreased by 25%, leading to the same reductions in SO2 and CO2 emissions (-7% by one zone).
- Production throughput can be increased by 15-20% (+6% by one zone).
Brach orders two more REBOX® installations
German steel producer Reiner Brach GmbH & Co KG has awarded Linde an order for two more REBOX® systems to be installed during 2009. Brach is an independent company located in Bremen, producing material for rolled steel finished products, such as ingots, forging semis, slabs, etc., from structural and high alloy steels grades. The steel rolled products are from 30 up to 800 mm thick and up to 2,500 mm wide. For its reheating Brach uses soaking pit furnaces.
The first REBOX® installation at Brach was carried out more than ten years ago. With the two new systems, there will be totally five soaking pit furnaces at Brach employing REBOX® oxyfuel technology. The main results and reasons for using more oxyfuel reheating at Brach include:
- Improved product quality due to more accurate temperature control and improved temperature uniformity
- Fuel consumption reduced by 25-40%
- Significant reductions in maintenance costs
- Increased productivity
- Improved environment performance with decreased emissions
Linde has been awarded a second contract at ASCOMETAL
More hot rolling capacity with REBOX® oxyfuel at ASCOMETAL, Les Dunes (France).
French special long steel products producer ASCOMETAL, member of Severstal group, has awarded Linde a second contract for REBOX® oxyfuel solutions in reheating. Four pit furnaces at ASCOMETAL, Les Dunes, will in a performance guarantee contract, during 2007-8 be converted into full oxyfuel operation to boost the rolling mill capacity and reduce fuel consumption while also reducing emissions of CO2 and NOx.
Jean-Pierre Riegert, head of Technologies and Development at ASCOMETAL, concludes: “REBOX® oxyfuel solutions will be implemented at Les Dunes, after its success in improving our utilization of existing equipment in the Fos-sur-Mer plant, achieving 33% shorter heating time and 40% lower fuel consumption with reduced emissions.”
Linde has since 1990 installed over 110 REBOX® oxyfuel solutions in reheating and annealing applications, both batch and continuous type furnaces.
Oxyfuel brings 30% capacity increase at ThyssenKrupp Steel
ThyssenKrupp Steel AG, TKS in Finnentrop, Germany produces galvanized strip for use in the automotive, white goods and for the construction industry. Linde installed the REBOX® oxyfuel solutions in the existing galvanizing line, which resulted in a production increase of 30%, from 82 to 105 tons per hour. Since oxyfuel not only effectively heats, contributing to a reduction of fuel consumption, it also cleans, thus eliminated the need for the pre-cleaning section.
Direct Flame Impingement (DFI) oxyfuel, where the oxyfuel flames are fired directly onto the moving metal was the chosen REBOX® solution. This drastically increasing the heat transfer for more throughput without extending the furnace or line. Three meters of the recuperative zone were refitted with a compact 5 MW DFI oxyfuel unit consisting of four burner row sets.
Fuel consumption was reduced by 6 percent and annealing properties over the entire strip width were improved. The strip surface was effectively cleaned from unwanted contaminants such as oil and residues, making it possible to remove a 25 meter strip pre-cleaning section.
By August 2006, Ovako will have REBOX® oxyfuel solutions for reheating in all 48 pit furnaces.
Oxyfuel in all pit reheat furnaces at Ovako, Sweden.
REBOX® for more furnace throughput with reduced fuel consumption and less emissions.
Ovako, Hofors works, Sweden have ordered an additional 8 REBOX® oxyfuel solutions for reheating from Linde. Since 1994, Ovako have implemented oxyfuel for increased throughput capacity for more flexibility, reduced fuel consumption and lower emissions of CO2 and NOx.
Since August 2006, the remaining soaking pit furnaces has converted to oxyfuel for a total of 48 pit and 2 rotary hearth furnaces operating with oxyfuel. Flameless oxyfuel will be employed for even faster and more uniform heating and lower emissions of NOx. The engineered solution is also prepared for a future possible conversion to natural gas.
Linde has since 1990 installed over 110 REBOX® oxyfuel solutions in reheating and annealing applications, both batch and continuous type furnaces.
By August 2006, Ovako will have REBOX® oxyfuel solutions for reheating in all 48 pit furnaces.
Forges Shops in Sweden upgrade to flameless oxyfuel from Linde
SCANA in Björneborg and UDDEHOLM TOOLING in Hagfors have upgraded to flameless oxyfuel in their car bottom furnaces. Both sites already have vast experience of REBOX® oxyfuel solutions in reheating since the first installation in 1993 at Hagfors and in 1997 at Björneborg.
Those installations were carried out to provide more production capacity, less fuel consumption and CO2 emissions in existing furnaces. The lower flame temperature and better heat distribution of flameless oxyfuel are aiming at further reduction of NOx emissions and improved uniform heating of the steel ingots prior to forging.
SCANA, Björneborg, Sweden equipped with REBOX® oxyfuel solutions in their car bottom furnace.
ThyssenKrupp Steel and Linde cooperate on oxyfuel applications in galvanizing operations.
ThyssenKrupp Steel AG and Linde AG have signed a cooperation agreement concerning development and implementation of new technology in galvanizing lines. The parties will use know-how and operational experience to further develop the use of Linde’s REBOX® oxyfuel solutions in reheating and annealing. The objective is increased plant performance and improved product quality by applying the so-called Direct Flame Impingement (DFI) oxyfuel technology in galvanizing operations. DFI implies that the oxyfuel flame is in direct contact with the object to be heated. This drastically increases the heat transfer (kW/m2) and when employed in an existing catenary furnace it resulted in 50% more throughput capacity.
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Firing with oxyfuel flames directly onto the material, the so-called Direct Flame Impingement technology, results in a highly effective heat transfer for increased furnace throughput
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