Electrical engineering, Electronics
– Kiln and furnace engineering
ELECTRICAL ENGINEERING, ELECTRONICS // KILN AND FURNACE ENGINEERING// ON- AND OFFSHORE ENGINEERING // POWER ELECTRONICS // MEASURING SYSTEMS // CONTROL SYSTEMS // WAFER PRODUCTION // ELECTRIC MOTORS // TELECOMMUNICATIONS // LIGHTING SYSTEMS // PHYSICAL RESEARCH // ELECTRONICS – GENERAL
For decades now, products made of oxide ceramic materials have been the standard for high-temperature engineering in the region of 2000 °C at industry and research institutes.
The typical requirements for these materials in operating conditions in oxidizing, inert and reducing atmosphere as well as in vacuum can be summarized as follows:
- Electrical insulation and gas-tightness in use for thermocouples.
- Electrical conductivity in operation as a λ sensor in firing systems.
- Resistance to high-temperature corrosion.
- Thermal shock resistance.
- Dimensional stability at high temperature.
High-purity oxide ceramic materials for such applications generally consist of Al2O3 and doped ZrO2. Especially Al2O3 is often unrivalled thanks to its attractive price-performance ratio.
Doped ZrO2 is often used in λ sensors for the optimization of the fuel-air ratio during firing in gas-heated kilns and furnaces.
For temperatures in excess of 2000 °C, thermocouples in the combination C – B4C are available for the control of temperature-time programs in non-oxidizing atmospheres. One advantage of such sensors is protective tubes and electrical insulating tubes are not necessary whereas such components would be required with the use of metallic thermocouple combinations such as W – Re or Mo – Re in such conditions.