Infrared Non-Contact Temperature Measurement in Glass Industry
Careful temperature monitoring during glass production plays important role. Temperature control has an impact on the actual quality and reliability of the finished glass. It ensures that the product quality meets stringent marketplace requirements.
In this process, molten glass flows into one or more fore hearths from the working tank or furnace and is cut by a shearing blade to form a cylinder of glass called a gob. The gob is dropped into moulds where the initial forming is done by either a blowing process with compressed air, or a pressing process using a plunger and mould.
It is important to maintain the proper temperature in the fore hearth to obtain the proper gob viscosity and the molten glass is in the proper homogenous condition when it reaches the exit because a temperature difference of 1 K causes a viscosity deviation of 1%. That’s why an infrared pyrometer is used along the fore hearth to monitor the molten glass temperature and control the fore hearth zone temperatures.
The AST models AST 450 G2, AST A450C FO-PL, PGM+ are used to measure the temperature in glass industries for different applications-
|Sections||Our Model||Temperature Range||Spectral Range|
|Working Tank/ Melting Tank||AST 450 G2||600°C to 1800°C||1 μm|
|Fore hearth||AST 450 G2||600°C to 1800°C||1 μm|
|Feeder||AST 450 G2||600°C to 1800°C||1 μm|
|Glass Gob||AST A450C FO-PL||600°C to 3200°C||0.7 μm … 1.15 μm|
|Container Glass Mould||PGM+||250°C to 600°C||1.6 μm|
The AST model A450G2 is a heavy duty fibre optics based 2-wire pyrometer with Digital Output which has been specifically designed to solve measurement problems and improve control of process temperatures in the glass industry in high ambient temperature conditions. This Model is designed for measurement of molten glass in Glass industries for melting tank, Fore hearth, Feeder and Working end.
For measuring the temperature of the glass gob, fast response time is required. The two colour pyrometer provides a response time of 20msec.
Efficient temperature control helps in achieving the desired container wall thickness. It is a ratio pyrometer which eliminates and reduces errors in temperature measurement caused by changes in Emissivity, Surface finish and energy absorbing materials such as water vapour etc.
The Fibre Optic Pyrometers are widely used in high ambient temperature applications.
The P-GM+ (Portable Glass Mould Pyrometer) is a hand held, battery powered Non-Contact pyrometer gives an instantaneous reading of the temperature and data logging. Readings taken are stored into memory and logged with Serial number and date/time for reviewing it.
The pyrometer has an infrared detector with associated electronics and a rigid fibre optic probe, the tip of which is momentarily touched to the hot surface to take measurement. The processor has an easy to read OLED display, operating button, and a data store. 3 AAA size rechargeable cell powers the whole system.