Thursday, 5. April 2018
Performance upgrade and process optimization
Vertical furnace optimized by OTTO JUNKER
In close cooperation between the engineering and maintenance department at Aurubis Zutphen and OTTO JUNKER, a concept was developed to replace the existing horizontal pre-heating zone with two additional vertical heating zones.
Aurubis Netherlands B.V. in Zutphen is one of four production sites of the Aurubis group’s Flat Rolled Products division. In Zutphen, 330 employees fabricate a wide range of rolled products made from copper and copper alloys with a current finished capacity of 50,000 tonnes p.a.
Strip with a thickness of up to 3 mm is annealed at approx.. 800°C in two vertical furnaces. Years ago, to improve performance, a radiation-heated zone was built into one of the furnaces to pre-heat the strip fed horizontally through this area. After leaving this pre-heating zone, the strip was then guided over several rollers into the vertical furnace.
In close cooperation between the engineering and maintenance department at a concept was developed to replace the existing horizontal pre-heating zone with two additional vertical heating zones. Particularly the deflection rollers used to guide the hot strip into the vertical furnaces were the cause of recurring quality problems due to scratches, as well as high maintenance costs. Despite making various improvements, such as special surface coatings or drives, these problems could never be avoided completely.
In addition, Aurubis wanted a strip clamping feature to reliably retain the strip above the furnace and prevent it from falling back into the accumulator structure in case of strip breakage.
A further challenge was the extremely tight schedule: from signing the contract up to delivery, only five and a half months were available to design, produce and deliver the solution!
To minimize production downtime, a short time frame of less than three weeks was planned for the actual installation and commissioning phases. Within this short space of time, the old furnace had to be dismantled and the new furnace, complete with new system components and new steel platform, installed and put into operation.
OTTO JUNKER supplied two completely new furnace zones designed as high convection zones fitted with the companies nozzle system. The upper section of the furnace was also sealed with a new entry lock chamber. Finally, the new strip-guiding devices, such as deflection rollers and the above-mentioned retaining mechanism, needed to be installed.
Right on time, the first coil was produced on the agreed production date. As time progressed, the various line parameters were adjusted, enabling production capacities for some alloys to be increased by up to 15 %!
The modification of this furnace is another excellent example of how major performance improvements can be achieved in existing furnaces when user’s operating experience is closely intermeshed with OTTO JUNKER know-how.
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Otto Junker is the global technology and system partner for thermal processes of the aluminium, copper, semi-finished products and foundry industry as well as a European supplier of special stainless steel castings. It has some 700 employees at 5 locations who generate worldwide sales of more than EUR 150 million. Sole owner of Otto Junker Group is the Otto Junker Foundation.
- Klaus Schmitz
OTTO JUNKER GmbH+49 2473 601-532+49 2473 601-620Jaegerhausstr. 22
D - 52152 Simmerath-Lammersdorf