ArcelorMittal Eisenhüttenstadt GmbH, Eisenhüttenstadt, Germany:

Hunger J., Dr. Eng., Head of Ironmaking Shop, joerg.hunger@arcelormittal.com

Buchwalder J., Director of Strategy and Technological Development 

Freude T., Dr. Eng., Head of Department of Prospective Planning

Paul Wurth Refractory & Engineering GmbH, Mainz Kastel, Germany:

Hebel R., Mag. Eng., Concultant

Premature refractory wear, especially at the zone between the tuyere surround and the lower bosh lining, typically leads to frequent tuyere and tuyere cooler leakages. The task was to develop a new cooling and lining system that prevents critical wear, such as lower bosh and upper tuyere lining erosion, as well as leakages of tuyere coolers and tuyere nozzles. The new angled system, Cu staves with refractory inserts and support ring coolers, was installed in 2005 at ArcelorMittal's blast furnace 5A in Eisenhüttenstadt (its view is presented in the paper). Since then it has improved the service life of bosh shell, tuyere coolers and nozzles. After five years of operation, the following should be noted. The copper stave plates with embedded refractory bricks apparently show no abrasive wear, as concluded from the core drill sample. The same conclusion can be drawn from the copper stave plate temperature readings. It can be confirmed that the steel mounting bracket stabilizes the copper staves and prevents thermally induced distortions of the plates. A principally new technical solution has been developed for the adaptation of the bosh angle for a given furnace geometry on one hand and the requirements of the blast furnace operation on the other. The significant improvement of the blow pipe service life, despite different furnace operating practices, can mainly be attributed to the adjustment of the bosh angle and to more stable cooling method of the refractories in the tuyere band, aided by the water cooled copper support ring.