Float Glass
The measurement of temperature at critical locations in the production process is essential for the full understanding and efficient control of float glass manufacture. The following illustrations represent some of the locations for these measurements and our recommendations for the best choice of instrument. If your specific area of interest is not covered here, our engineers will be pleased to discuss your requirements with you.
Document download: Flat Glass 17-05-2011_w.pdf
4. Tank Outer Surface - Float Glass
The condition and safety of the furnace refractories are vitally important, especially as the end of a campaign approaches. A LAND thermal imager or a portable thermometer from the Cyclops range can be used to make routine checks on key areas of the tank to minimize the possibility of glass break-out or refractory failure.
Land Instruments recommends:
1. Regenerator
Accurate and reliable temperature measurement of the crown and packing is essential for this important and vulnerable area of the tank. Thermocouples, despite their lower initial cost, can rapidly deteriorate. Infrared thermometers provide a long-term, cost effective and more reliable measurement.
6. Tin Bath
A knowledge of the temperature profile is vital in this area for the production of consistently high quality glass. When glass is just a few millimetres thick, selected waveband thermometers operating in a narrow band around 5µm are used to accurately measure the surface temperature of the product.
Land Instruments recommends:
5. Canal
The choice of thermometers here is dependent on the construction and operation of the canal. Short wavelength thermometers (Fibroptics, M1 and Solo1) will measure the bulk temperature of the glass.
Land Instruments recommends:
7. Break Detector
Measurement here is used to highlight any breakages of the glass. Acting as a simple 'presence detector', a thermometer placed at this point aids the complete automation of the process.
Land Instruments recommends:
8. Lehr, 9. Exit 10. Washer
As the rate of cooling in the lehr is so important, frequent accurate measurement of the temperature profile is critical. For temperatures above 300°C, 5?m thermometers are recommended, but as temperatures fall below 300°C the long wavelength thermometers should be used so extending the capability of measurement down to ambient levels.
Land Instruments recommends:
3. Tank Roof
Thermocouples have been used for many years for this crucial measurement. However, at the high temperatures at which they operate deterioration can be rapid and often undetectable due to contamination of the element and migration of elementary materials from one wire to the other. Land Fibroptic thermometers overcome these problems, and operate without the need for water cooling.
Land Instruments recommends:
2. Port Arch
Measurement of the port arches, especially in cross-fired furnaces, can provide important information on basic firing conditions, giving early indication of an incorrect or unbalanced firing situation.
Land Instruments recommends:
Float Glass Surveys
The JRG/A is a temperature survey probe for plate and float glass in hot surroundings. It can be used in the float bath to provide spot temperatures to ensure uniformity of glass temperature gradients.
