A multitude of tasks for the P-series ThermaCAM™
„Temperature tracking through the use of infrared thermography has proven invaluable within our industry”, says Dirk
Ehrlich, a technician at HKM’s Energy Management Department. Ehrlich and
his colleagues measure and calculate parameters such as heat and gas
development, energy flows, or dust concentration which are needed to
determine and eventually to optimise and reduce the plant’s energy
output. „And“ he adds,“ infrared cameras enable a faster inspection in
critical, inaccessible or potentially hazardous environments“.
During the casting, an infrared camera is used to
monitor the heat load on engines, gears, and other elements as well as
the proper functioning of the cooling of the rollers. Risks are at hand:
the proper functioning of the plant can be endangered by rollers, which
are in direct contact with 1,000 °C hot molten steel rounds as well as
structural casting plant elements which are directly exposed to heat
radiation.
Semi-finished steel slabs produced in the continuous casting plants are usually cooled down in stacks. For the onward transportation of the slabs (for example, to the hot-mill strip to be rolled into coiled sheet and plat products) specific temperature limits need to be maintained. Thermography hardware and software allows to compare the actual temperature with the computed, pre-scheduled temperature at various points to optimise the process. At a sintering plant, iron-bearing particles are formed into pellets or pulverized to be charged again into the blast furnace. The sinter, which is still hot after the production process, is transported via a conveyor belt to the sinter coolers. Thermography is particularly useful to determine the average temperature distribution of the sinter in order to assess the heat load on the sinter cooler.
 |
Continuous casting systems 1. furnace and furnace gate 2. ladle and ladle gate 3. tundish and sliding gates 4. Tube changer with stopper 5. Tundish sliding gate 6. Tundish sliding gate with tube changer 7. Calibrated nozzle changer 8. Stopper control systems 9. Mold level control |
Inspecting refractory lining defects
Refractory materials are needed, among others, to prevent fire development during the casting process. They are exchanged after a few hours of operation. Their quality and performance are vital to a clean, safe and streamlined production process.
“We regularly inspect the tank lid of a vacuum
chamber after a steel melting operation, to check the heat load of the
lid” says Ralf Ponczeck, another team member of HKM’s Energy Management
Department.
The surface of the two pig iron mixers, each with a
capacity of 2,000 tonnes, is regularly checked for partial temperature
overshoots, to identify as early as possible any damage which has
occurred in the refractory lining. Also checked on their refractory
level are so-called torpedo ladles. They are used to conveying the
liquid pig iron from the blast furnaces to the oxygen steel works. Here
too, thermographic imaging enables clear conclusions to be drawn about
the state of the inner refractory lining.
The team also inspects the functioning of the converters‘ floor flushers. As flushing takes place via the floor using inert gases, the openings need to remain clear. The heat distribution can be captured by an infrared image. ”Due to the high thermal radiation in this and similar measurements, we use a a telephoto lens to protect the ThermaCAM. This also makes it easier to film more remote objects, such as hot pipe routes”, says Alfred Lichtweg, Energy Management Department team member.
 |
 |
Defective control module (second from right)
Other current time- and money-saving applications are checking pipelines for deposit build-up or inspecting machinery which keep the steel product fabrication steps going. HKM also makes use of infrared thermography to optimise its production processes: alternative refractory linings, for example have been extensively tested at the plant with infrared cameras as they allow an accurate observation of temperature cycles across entire surface areas.
A FLIR Systems ThermaCAM P-series is are a very
useful tool to reach, access, and inspect hot and hazardous areas
typical for the metallurgic industry. And it helps to keep a vital and
strategically important industry sector going: “After all,” says Dirk
Ehrlich, “there’s something from HKM in every made-in-Germany truck or
car: 12 percent to be exactly.”
This story was based on an article authored by Dirk Ehrlich of HKM and free-lance journalist Frank Liebelt, Frankfurt, Germany
