초록 ▼

A soda-lime-silica glass for solar collector cover plates and solar mirrors has less than 0.010 weight percent total iron as Fe2O3, a redox ratio of less than 0.350, less than 0.0025 weight percent CeO2, and spectral properties that include a visible transmission, and a total solar infrared transmit

A soda-lime-silica glass for solar collector cover plates and solar mirrors has less than 0.010 weight percent total iron as Fe2O3, a redox ratio of less than 0.350, less than 0.0025 weight percent CeO2, and spectral properties that include a visible transmission, and a total solar infrared transmittance, of greater than 90% at a thickness of 5.5 millimeters, and reduced solarization. In one non-limiting embodiment of invention, the glass is made by heating a pool of molten soda-lime-silica with a mixture of combustion air and fuel gas having an air firing ratio of greater than 11, or an oxygen firing ratio of greater than 2.31. In another non-limiting embodiment of the invention, streams of oxygen bubbles are moved through a pool of molten glass. In both embodiments, the oxygen oxidizes ferrous iron to ferric iron to reduce the redox ratio.

대표청구항 ▼

1. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O30.005-0.120 weight percentRedox ratio

1. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O30.005-0.120 weight percentRedox ratioin the range of 0.15-0.286CeO2less than 0.0025 weight percentZrO2less than 0.01 weight percent andTiO2less than 0.01 weight percent, and wherein spectral properties of the glass measured at a thickness 5.5 millimeters comprises: a visible transmission of greater than 85% measured using C.I.E. standard illuminant “A” with a 2° observer over a wavelength range of 380 to 770 nanometers;a total solar infrared transmittance of greater than 87% measured over a wavelength range of 775 to 2125 nanometers, anda total solar energy transmittance of greater than 90% measured over a wavelength range of 300 to 2500 nanometers, wherein the total solar infrared transmittance and the total solar energy transmittance are calculated using Parry Moon air mass 2.0 direct solar irradiance data and ASTM air mass 1.5 global solar irradiance data respectively, and integrated using the Rectangular Rule and Trapezoidal Rule, respectively. 2. The glass according to claim 1 wherein the spectral properties comprise: the visible transmission is greater than 87%, andthe total solar infrared transmittance of greater than 89%. 3. The glass according to claim 1 wherein the spectral properties comprise: the visible transmission is greater than 90%, andthe total solar infrared transmittance of greater than 90%. 4. The glass according to claim 1 wherein weight percent of ingredients that oxidize Fe++ to Fe+++ other than those listed in claim 1 is less than 0.0025 weight percent. 5. The glass according to claim wherein the redox ratio is in the range of 0.15-0.27. 6. The glass according to claim 1 wherein the redox ratio is in the range of 0.15-0.19. 7. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O30.005-0.025 weight percent,Redox ratioless than 0.350,CeO2less than 0.0025 weight percent,ZrO2less than 0.01 weight percent andTiO2less than 0.01 weight percent, and wherein spectral properties of the glass measured at a thickness 5.5 millimeters comprises: a visible transmission of greater than 90% measured using C.I.E. standard illuminant “A” with a 2° observer over a wavelength range of 380 to 770 nanometers;a total solar infrared transmittance of greater than 90% measured over a wavelength range of 775 to 2125 nanometers, anda total solar energy transmittance of greater than 90% measured over a wavelength range Of 300 to 2500 nanometers, wherein the total solar infrared transmittance and the total solar energy transmittance are calculated using Parry Moon air mass 2.0 direct solar irradiance data and ASTM air mass 1.5 global solar irradiance data respectively, and integrated using the Rectangular Rule and Trapezoidal Rule, respectively. 8. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O30.005-0.025 weight percentRedox ratioless than 0.200CeO2less than 0.0025 weight percentZrO2less than 0.01 weight percent andTiO2less than 0.01 weight percent, and wherein spectral properties of the glass measured at a thickness 5.5 millimeters comprises: a visible transmission of greater than 85% measured using C.I.E. standard illuminant “A” with a 2° observer over a wavelength range of 380 to 770 nanometers;a total solar infrared transmittance of greater than 87% measured over a wavelength range of 775 to 2125 nanometers, anda total solar energy transmittance of greater than 90% measured over a wavelength range of 300 to 2500 nanometers, wherein the total solar infrared transmittance and the total solar energy transmittance are calculated using Parry Moon air mass 2.0 direct solar irradiance data and ASTM air mass 1.5 global solar irradiance data respectively, and integrated using the Rectangular Rule and Trapezoidal Rule, respectively. 9. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O3equal to or less than0.01 weight percent,Redox ratioless than 0.200CeO2less than 0.0025 weight percentZrO2less than 0.01 weight percent andTiO2less than 0.01 weight percent, and wherein spectral properties of the glass measured at a thickness 5.5 millimeters comprises: a visible transmission of greater than 85% measured using standard illuminant “A” with a 2° observer over a wavelength range of 380 to 770 nanometers;a total solar infrared transmittance of greater than 87% measured over a Wavelength range of 775 to 2125 nanometers, anda total solar energy transmittance of greater than 90% measured over a wavelength range of 300 to 2500 nanometers, wherein the total solar infrared transmittance and the total solar energy transmittance are calculated using Parry Moon air mass 2.0 direct solar irradiance data and ASTM air mass 1.5 global solar irradiance data respectively, and integrated using the Rectangular Rule and Trapezoidal Rule, respectively. 10. A soda-lime-silica glass, comprising: SiO265-75weight percentNa2O10-20weight percentCaO5-15weight percentMgO0-5weight percentAl2O30-5weight percentK2O0-5weight percentSO30-0.30weight percent and a colorant portion consisting essentially of: Total iron as Fe2O3greater than 0.01 to 0.12weight percent,Redox ratio isless than 0.150,CeO2less than 0.0025 weight percent,ZrO2less than 0.01 weight percent andTiO2less than 0.01 weight percent, and wherein spectral properties of the glass measured at a thickness 5.5 millimeters comprises: a visible transmission of greater than 85% measured using C.I.E. standard illuminant “A” with 2° observer over a wavelength range of 380 to 770 nanometers;a total solar infrared transmittance of greater than 87% measured over a wavelength range of 775 to 2125 nanometers, anda total solar energy transmittance of greater than 90% measured over a wavelength range of 300 to 2500 nanometers, wherein the total solar infrared transmittance and the total solar energy transmittance are calculated using Parry Moon air mass 2.0 direct solar irradiance data and ASTM air mass 1.5 global solar irradiance data respectively and integrated using the Rectangular Rule and Trapezoidal Rule, respectively.