Date of Award


Document Type

Campus Access Thesis


Mechanical Engineering

First Advisor

Jamil Khan


In the manufacture of high tensile strength, continuous glass fiber (S-Glass), the temperature of the molten glass must be measured and controlled. The control of the glass temperature is important for obtaining the correct physical and mechanical properties of the glass, ensuring an efficient and continuous fiber forming process, and protecting the equipment used to melt the glass. At temperatures greater than 1700°C traditional methods of molten glass temperature measurement yield less than the desired accuracy and reliability needed for S-Glass production. The purpose of this research project is to design, test, and control a glass melting unit that will allow for accurate and reliable measurement of molten glass at the standard S-Glass processing temperatures.

An S-glass melting unit was designed and built with an integral thermal well that allowed access for a thermocouple or infrared sensor to read under glass temperature. Both sensor types were tested and the thermal well / thermocouple design was selected for a production trial. Differences in the temperature values were found between the standard method and the trial method and were explained with heat transfer analysis.

Control values were determined for PID control of the thermocouple signal from the thermal well location and the glass temperature was controlled by the process PLC. This method of temperature measurement was found to be much improved over the standard method. The thermal well design was successful in dramatically increasing the life of the current sensor as well as protecting the sensor from drift. Finally, the PLC control significantly reduced temperature variation over the historical open loop control.