Huber, AM
1999
Predicted and Measured Glass Surface Temperatures in an Industrial, Regenerative, Gas-Fired, Flat-Glass Furnace
Hayes, R.R.; Wang, J.; McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Glastechnisched Berichte - Glass Science and Technology, August 1999.
This study reports optically measured glass surface temperatures along the furnace centerline in the combustion space of a side-port, 550-ton/day industrial, gas-fired flat glass furnace. The measurements were made using a water-cooled two-color pyrometer inserted through holes in the crown at six locations along the length of the furnace. Both average and time-resolved glass surface temperature measurements were performed during the approximately 20-second reversal period of the furnace. The measured glass surface temperature data are supplemented by observations of the batch location using a specially designed, water-cooled video probe. The average temperatures were found to rise from a low near 1700 K near the batch blanket to a peak of approximately 1900 K, and then drop to a level of 1800 K. Evidence of batch islands or "logs" is observed in the surface temperature data collected at the measurement location nearest the batch blanket; large temperature excursions are seen here, indicative of measurement alternately of both the batch surface and the molten glass. Also reported in this study are results of a numerical model for the three-dimensional melt flow and heat transfer in the tank, coupled with a batch melting model. The radiant heat flux distribution incident on the melt and batch blanket surfaces is assumed. The melt tank model includes bubbling. The numerical predictions agree well with the time-averaged glass surface temperature data collected experimentally. The measurements and model predictions illustrate the complex transport phenomena in the melting section of the furnace.
The Effect of Rebuild on the Combustion Performance of an Industrial Gas-Fired Flat Glass Furnace
McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Combustion Science and Technology, Revised, March 1999.
Post-rebuild profiles of velocity, species concentration (O2, CO, and CO2), and gas temperature are reported in the portnecks of a regenerative, side-port, 550-ton/day, gas-fired, flat-glass furnace. These measurements are also compared to similar ones made before the same furnace was rebuilt. Measurements were also made below one of the regenerators in the tunnel leading to the furnace stack after the rebuild. Fewer variations were observed in the exhaust profiles of most measured variables after the rebuild. Flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s before and after the rebuild. The temperature of the inlet preheat air was generally speaking higher and the furnace exhaust temperature lower before the rebuild. Locations of low O2 concentration in the effluent are consistent with high CO concentrations before and after the furnace rebuild. CO2 concentrations are nearly uniform across the portneck height, more so after the rebuild. The measurements in the tunnel after the rebuild indicate a stratification effect in the species concentration measurements. These measurements also indicate that the combustion reactions continue inside the regenerators resulting in overall complete combustion as indicated by the very low CO levels in the tunnel. A mass balance analysis for the overall combustion reaction based on the measurements of O2 and CO2 and fuel flow rate in each port showed that (1) before and after the furnace rebuild the predicted CO2 formed in the glass is within 15% of the value estimated by Ford personnel; and (2) the overall stoichiometry was not much different before and after the rebuild (22.5% excess air before compared to 19.2% after). The total airflow rate calculated by this analysis after the rebuild is within 9% of the plant-measured value.
Huber, AM
1999
Predicted and Measured Glass Surface Temperatures in an Industrial, Regenerative, Gas-Fired, Flat-Glass Furnace
Hayes, R.R.; Wang, J.; McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Glastechnisched Berichte - Glass Science and Technology, August 1999.
This study reports optically measured glass surface temperatures along the furnace centerline in the combustion space of a side-port, 550-ton/day industrial, gas-fired flat glass furnace. The measurements were made using a water-cooled two-color pyrometer inserted through holes in the crown at six locations along the length of the furnace. Both average and time-resolved glass surface temperature measurements were performed during the approximately 20-second reversal period of the furnace. The measured glass surface temperature data are supplemented by observations of the batch location using a specially designed, water-cooled video probe. The average temperatures were found to rise from a low near 1700 K near the batch blanket to a peak of approximately 1900 K, and then drop to a level of 1800 K. Evidence of batch islands or "logs" is observed in the surface temperature data collected at the measurement location nearest the batch blanket; large temperature excursions are seen here, indicative of measurement alternately of both the batch surface and the molten glass. Also reported in this study are results of a numerical model for the three-dimensional melt flow and heat transfer in the tank, coupled with a batch melting model. The radiant heat flux distribution incident on the melt and batch blanket surfaces is assumed. The melt tank model includes bubbling. The numerical predictions agree well with the time-averaged glass surface temperature data collected experimentally. The measurements and model predictions illustrate the complex transport phenomena in the melting section of the furnace.
The Effect of Rebuild on the Combustion Performance of an Industrial Gas-Fired Flat Glass Furnace
McQuay, M.Q.; Webb, B.W. and Huber, A.M.
Combustion Science and Technology, Revised, March 1999.
Post-rebuild profiles of velocity, species concentration (O2, CO, and CO2), and gas temperature are reported in the portnecks of a regenerative, side-port, 550-ton/day, gas-fired, flat-glass furnace. These measurements are also compared to similar ones made before the same furnace was rebuilt. Measurements were also made below one of the regenerators in the tunnel leading to the furnace stack after the rebuild. Fewer variations were observed in the exhaust profiles of most measured variables after the rebuild. Flat inlet velocity profiles were measured with a magnitude of approximately 11 m/s before and after the rebuild. The temperature of the inlet preheat air was generally speaking higher and the furnace exhaust temperature lower before the rebuild. Locations of low O2 concentration in the effluent are consistent with high CO concentrations before and after the furnace rebuild. CO2 concentrations are nearly uniform across the portneck height, more so after the rebuild. The measurements in the tunnel after the rebuild indicate a stratification effect in the species concentration measurements. These measurements also indicate that the combustion reactions continue inside the regenerators resulting in overall complete combustion as indicated by the very low CO levels in the tunnel. A mass balance analysis for the overall combustion reaction based on the measurements of O2 and CO2 and fuel flow rate in each port showed that (1) before and after the furnace rebuild the predicted CO2 formed in the glass is within 15% of the value estimated by Ford personnel; and (2) the overall stoichiometry was not much different before and after the rebuild (22.5% excess air before compared to 19.2% after). The total airflow rate calculated by this analysis after the rebuild is within 9% of the plant-measured value.