The Application of Infrared Thermometers in the Glass Industry
In the production process of the glass industry, temperature measurement and control is a very important and necessary means. Infrared temperature measurement is valued for its simple operation, fast response speed, non aging, small drift, flexible configuration, and no pollution of glass solution.
In the glass industry, it is necessary to measure the temperature of transparent and opaque objects. Opaque objects include molds, domes, and side walls of glass melting furnaces. As a non-contact temperature measurement object, glass is transparent and visible, with its spectrum within the near-infrared spectral range. Its emissivity is related to wavelength and glass thickness. When the spectral range is between 5-8 μ When m is between, its emissivity * is high, so the temperature of the glass can be reliably measured within this range. The measured values correspond to the surface temperature of the glass, are independent of the thickness of the glass, and are within this range with almost no radiation. In order to avoid the influence of ambient air on the measurement, the thermometer only uses a very narrow infrared spectral band. A high-quality thermometer only operates within the spectral range of this so-called environmental window, as there is no absorption of infrared rays due to air humidity or carbon oxides, thus avoiding temperature measurement errors caused by changes in air humidity or measurement distance. Narrowband range 5 (approximately 5 μ m) Used to measure the surface temperature.
Infrared thermometers generally have 5.14 μ The spectral range of m works because the hot exhaust gas from the combustion head in this area will not affect the measured values. For other application ranges, it is necessary to measure the temperature inside the glass, as the glass layer near the surface is greatly affected by convection. What needs to be measured here is the melted glass, which requires the use of a thermometer in the near-infrared range. Because the penetration depth achieved at different wavelengths also varies, the choice of thermometer depends on the thickness of the glass layer. Non contact temperature measurement technology for glass furnaces, tin baths, and annealing kilns is increasingly replacing traditional thermocouple temperature measurement in glass furnaces.
Compared to thermometers, thermocouples quickly age and drift under high operating temperatures and corrosive environmental conditions. In order to protect thermocouples, some places require platinum metal as a protective shell, which will increase the cost significantly. Specially used in this field, the cooling system can work even when the ambient temperature reaches 250 ℃ without the need for cooling. By using a fiber optic pyrometer, installation and operation costs can be significantly reduced. The fiber optic can be protected by a sturdy stainless steel casing, and can reach a length of up to 30 meters. Required installation accessories such as mounting brackets, air cleaners, and peep tubes (can be used up to 1200 ℃).
