Cooling curve monitoring in glass annealing lehrs
Published: 18 December 2018 - Sarah Mead
Thermalert 4.0 spot pyrometers from Fluke Process Instruments enable precise monitoring of critical glass manufacturing processes such as annealing of glass bottles and containers. The non-contact infrared sensors measure product as well as belt temperatures. That way, operators can ensure that the lehr is set correctly for products with different glass thicknesses and sizes, and that the transportation belt is heated correctly. The latter is especially important for glass containers with a thick bottom, to prevent uneven cooling and breakage. Continuous monitoring helps operators improve quality and uniformity and reduce reject rates. It also supports troubleshooting by detecting faulty burners under the transportation belt.
The annealing process is designed to remove residual stress in formed containers. Obtaining the correct temperature and cooling curve is essential to achieve the required strength in the finished product. Temperature monitoring in this process also serves to confirm correct cure of decorative print or coatings. The high-accuracy Thermalert 4.0 spot pyrometer series comprises various wavelength models for different materials, including two specialised glass models. A peak hold function enables monitoring of moving glass containers. The series covers measured temperatures between -40 °C and 2250 °C. The infrared thermometers have the largest ambient temperature range in their class: -20 °C to 85 °C. Therefore, many measuring points can be set up without cooling accessories, saving costs. Moreover, the sensors can be read out, configured, calibrated, and fitted with firmware updates remotely via the internet. This minimises service costs per measuring point. Fluke Process Instruments industry specialists will be happy to advise customers on selecting and setting up the ideal measuring solution for their plant.