Our enhanced service portfolio for copper staves covers their entire lifecycle. This includes checking the health status of the staves by monitoring and measuring the erosion of the ribs, providing temporary repair kits for cooling channel damage that causes water and gas leaks, supplying high-performance copper staves, and replacing the copper staves in record time, thereby minimizing shutdown periods.
Health check
Understanding the thickness profile of copper stave ribs provides us with valuable insights for estimating the remaining life of the cooling system, allowing owners to take corrective action and delay any wear. Thanks to Paul Wurth’s Continuous Thickness Measurement Probe (CTMP), we can precisely measure the actual thickness of the ribs (with an accuracy of ±1.0 mm) that may be affected by wear due to burden abrasion. This portable ultrasonic measuring system, which runs inside the cooling channels, consists of an ultrasonic probe, an instrument detector, and an encoder. Each channel measurement is conducted during a shutdown and takes about 15 minutes. The recorded data are analyzed and consolidated in a comprehensive report. The measurement should be repeated every six to nine months on each channel, in order to monitor rib wear progression
Repair kits for water and gas leaks
Our repair kits assist customers in managing the cooling circuits and limiting reduced production output while waiting for a new copper stave to be installed. To prevent water and gas leaks resulting from cooling channel damage, we offer a range of Paul Wurth repair kits:
- Flexible hoses, which prevent water leaks from pitch in the hot face, are installed along the channel length and are closed off with special nozzles. To transfer the cooling effect, the kit is installed with an injection of a special conductive paste between the external body of the hose and the internal part of the cooling channel.
- The Stave Internal Repair Cartridge (SIRC) is a stave cartridge that is inserted in the cooling pipe, thus creating a new water flow duct and bypassing any crack leaks. It effectively solves leakage problems at the junction between the cooling pipe and copper stave body.
Gas leaks caused by failed seals at the connection between the cooling pipe and blast furnace shell (expansion joint) are resolved with the special fireproof rubber sealing, which is tightly connected from the cup welded on the shell and cooling pipe as well as the metal sealing, which is welded on the shell.
High-performance copper staves
Our high-performance copper staves minimize the potential for deformation, even after several years in operation. They are designed with the appropriate body shape and take into account shell bending and thermal dilatation. These copper staves can be equipped with patented accessories aimed at preventing rib abrasion: iron blades and inserted iron/refractory bricks.
Replacement of copper staves
Through swift and non-intrusive health checks, retrofit repair solutions, and innovative stave replacement techniques implemented during scheduled maintenance shutdowns (typically lasting no more than three to four days), we offer our customers a viable strategy to minimize production losses. The estimated cost of each ton of hot metal not produced during extended, unprepared shutdowns is approximately 20 to 25 US dollars.
Our stave replacements during these short shutdowns are carried out without the need for personnel working inside the blast furnace. The burden is lowered just under the bottom row, and the copper staves are removed externally using customized erection tools that are specially tailored to the blast furnace’s geometry.
Moreover, we have the expertise to assist our customers with salamander tapping, providing insights for estimating the residual liquid metal, identifying optimal drilling points, and selecting the most suitable drilling technology and contractor.
Continuous monitoring
Paul Wurth copper staves can be equipped with a fixed monitoring probe, which comprises a copper rod that is inserted inside as far as the rib front face. Its degree of wear is the same as the rib, therefore extracting it manually (during shutdown) or taking an external ultrasonic measurement provides an estimate of the residual length of the rib with an accuracy of ±0.5 mm. The external system can be integrated with a wireless device connected to the automation system, Smart Stave Sensor (SSS). This system sends continuous information on the wear to the control room. Both systems can be installed in existing copper staves during dedicated shutdowns.