Thermal Box-Barriere. The device for temperature measurement inside the industrial continuous furnaces.
- Thermal box-barriere (TBB) - device for temperature measurement inside continuous furnaces
- Industrial continuous furnaces measurement - furnace atmosphere and charge temperature
- Box-barriere thermal endurance: several hours at furnace atmosphere about 1200 °C with max. TBB inside temperature up to 60 °C
- Temperature measurement by thermocouples
Industrial continuous furnaces belong to important consumers of thermal energy. Optimization of their operation brings improvement of technological processes, more efficient charge heating or decrement of energy consumption. Implementation of a furnace optimization system requires good knowledge of heat-transfer processes inside the furnace: furnace atmosphere temperature, temperature of charge etc. These information can be determined only by a measurement. The measurement in continuous furnaces is a quite complicated because of high temperatures, continuously moving charge and other technological conditions. One of the possible measurement method is based on trailing thermocouples. In this case, the long thermocouples are connected to the measured charge and trailed over the whole furnace outside the furnace, where they are connected to a data acquisition device. This method is very complicated, expensive and the measurement is not too accurate because of thermocouples length. Therefore, a method based on thermal box-barrier was developed and applied in a real measurement.
Thermal box-barrier (TBB) is a special type of a technical thermal barrier. It is used to protect a device inside the barrier against a high temperature environment or mechanical damage. A special multi-layered structure of the barriere provides a sufficient thermal protection and allows its moving throughout the furnace together with the charge. Time and position evolution of the charge and furnace temperature are measured by thermocouples near the TBB and logged into a data acquisition device inside the TBB. The TBB protect the electronic device with maximum service temperature about 60 °C against high temperature inside the furnace, which can exceed 1200 °C. The performed experiments verified that it is possible to measure furnaces of length of several tens of meters in steelworks production lines, where the passage throughout the furnace takes several hours. However, the TBB shape, dimensions and internal structure can vary according to requirements and limitations given by the measured furnace. The requirements and limitations are generally very specific for different technologies. Therefore, a thermal box-barrer is designed for each project individually by a special software developed for these purposes.
Only few commercial companies worldwide offer a similar product, however, most of the offered devices are designed for lower temperatures and shorter times in a high temperature environment.
The measurement method and the thermal box-barrier device were successfully applied for several measurements in different continual furnaces:
- Železárny Hrádek (Ironworks), Czech Republic, pusher type gas furnace for steel slabs reheating
- Stahlwerk Thueringen (Ironworks), Germany, pusher type gas furnace for steel slabs reheating
- Sochorová válcovna Kladno (Billet mill), Czech Republic, walking beam gas furnace for steel billets reheating
- ArcelorMittal Ostrava (Rolling mills), Czech Republic, walking beam gas furnace for steel slabs reheating
- Kovárna Viva Zlín (forging), Czech Republic, continuous furnace for forgings reheating
- Thermal box-barrier for a direct measurement in high temperature environment, Applied Thermal Engineering, Vol. 27, No. 2-3, pp. 560-567, 2007, ISSN: 1359-4311
- Temperature and heat transfer measurement in continuous reheating furnaces. Scandinavian Journal of Metallurgy, Vol.32, No.5. pp.225-232, 2003, ISSN 0371-0459 Honner M., Veselý Z., Švantner M., Čejka F.: Optimal heating control system for continuous furnaces. Industrial Heat Engineering, Vol.23, No.3. pp.105-111, 2001, ISSN 0204-3602
- Optimization of continuous industrial furnace operation. Proc. of the 6th European conference on Industrial Furnaces and Boilers - INFUB 2002, Lusíada University (Portugal), University of Glamorgan (UK), University of Karlsruhe (Germany), 2nd-5th April 2002, Lisboa, Portugal, pp.85-94, 2002, ISBN 972-8034-05-9.
- Temperature and heat transfer measurements in continuous furnaces. Proc. of the 6th European conference on Industrial Furnaces and Boilers - INFUB 2002, Lusíada University (Portugal), University of Glamorgan (UK), University of Karlsruhe (Germany), 2nd-5th April 2002, Lisboa, Portugal, pp.95-104, 2002, ISBN 972-8034-05-9.