Abstract: A system for preheating batch materials includes a preheater, a charger, a first temperature sensor, a second temperature sensor, a valve, and a charger temperature controller. A first recirculation duct provides exhaust fluids from the charger to a second recirculation duct coupled to an inlet of the preheater. The first temperature sensor is configured to generate a first temperature signal indicative of a first temperature of fluids within the second recirculation duct and the second temperature sensor is configured to generate a second temperature signal indicative of a second temperature of the fluids within the second recirculation duct upstream of where the first temperature is obtained. The valve is configured to control an amount of fluid in the second recirculation duct that is diverted to the charger and the charger temperature controller is configured to control the valve responsive to the first and second temperatures.

Abstract: A system for preheating batch materials includes a preheater, a charger, a first temperature sensor, a second temperature sensor, a valve, and a charger temperature controller. A first recirculation duct provides exhaust fluids from the charger to a second recirculation duct coupled to an inlet of the preheater. The first temperature sensor is configured to generate a first temperature signal indicative of a first temperature of fluids within the second recirculation duct and the second temperature sensor is configured to generate a second temperature signal indicative of a second temperature of the fluids within the second recirculation duct upstream of where the first temperature is obtained. The valve is configured to control an amount of fluid in the second recirculation duct that is diverted to the charger and the charger temperature controller is configured to control the valve responsive to the first and second temperatures.

Abstract: A system for preheating batch materials in a glass melting furnace includes a preheater having an outlet through which fluid is exhausted and an inlet that receives fluids exhausted from the furnace and recirculated from the preheater outlet. In one embodiment, a cyclonic separator has an inlet in communication with the preheater outlet and an outlet in fluid communication with a fan. A controller controls the speed of the fan responsive to a drop in pressure between the separator inlet and outlet and a temperature at the separator outlet. In other embodiments, controllers control valves that (i) control the amount of fluids exhausted from the preheater that are delivered to a flue and recirculated to the preheater or (ii) control the amount of fluids diverted to charger for the furnace, in response to temperatures in a duct coupled to the preheater inlet.

Abstract: A process and apparatus for manufacturing glass. A mixture of solid glass-forming materials comprising at least one fining agent are introduced into a doghouse located upstream of an elongated tank. The glass-forming materials are melted in the doghouse at a temperature at or above a fining-onset temperature of the at least one fining agent by application of heat from one or more submerged combustion burners. The resulting molten glass is relatively foamy and may comprise greater than 25 vol. % gas bubbles. The molten glass is directed from the doghouse into an upstream end of the tank where it is refined to produce molten glass having on average less than 20 seeds per ounce.

Abstract: A system for preheating batch materials in a glass melting furnace includes: a preheater configured to receive unheated batch materials and to deliver heated batch materials, the preheater including an outlet configured to exhaust fluid from the preheater and an inlet configured to receive exhaust fluid from the glass melting furnace and exhaust fluid recirculated from the outlet of the preheater; a fan configured to provide ambient air to a furnace flue; a valve configured to control an amount of the ambient air to the furnace flue; a temperature sensor configured to sense temperature of exhaust gases in the furnace flue; and a temperature controller configured to control the valve and the fan responsive to the temperature sensed by the temperature sensor.

Abstract: A system for preheating batch materials in a glass melting furnace includes a preheater having an outlet through which fluid is exhausted and an inlet that receives fluids exhausted from the furnace and recirculated from the preheater outlet. In one embodiment, a cyclonic separator has an inlet in communication with the preheater outlet and an outlet in fluid communication with a fan. A controller controls the speed of the fan responsive to a drop in pressure between the separator inlet and outlet and a temperature at the separator outlet. In other embodiments, controllers control valves that (i) control the amount of fluids exhausted from the preheater that are delivered to a flue and recirculated to the preheater or (ii) control the amount of fluids diverted to charger for the furnace, in response to temperatures in a duct coupled to the preheater inlet.

Abstract: A system for preheating batch materials in a glass melting furnace includes a preheater having an outlet through which fluid is exhausted and an inlet that receives fluids exhausted from the furnace and recirculated from the preheater outlet. In one embodiment, a cyclonic separator has an inlet in communication with the preheater outlet and an outlet in fluid communication with a fan. A controller controls the speed of the fan responsive to a drop in pressure between the separator inlet and outlet and a temperature at the separator outlet. In other embodiments, controllers control valves that (i) control the amount of fluids exhausted from the preheater that are delivered to a flue and recirculated to the preheater or (ii) control the amount of fluids diverted to charger for the furnace, in response to temperatures in a duct coupled to the preheater inlet.

Abstract: A process and apparatus for manufacturing glass. A mixture of solid glass-forming materials comprising at least one fining agent are introduced into a doghouse located upstream of an elongated tank. The glass-forming materials are melted in the doghouse at a temperature at or above a fining-onset temperature of the at least one fining agent by application of heat from one or more submerged combustion burners. The resulting molten glass is relatively foamy and may comprise greater than 25 vol. % gas bubbles. The molten glass is directed from the doghouse into an upstream end of the tank where it is refined to produce molten glass having on average less than 20 seeds per ounce.

Abstract: A system for preheating batch materials in a glass melting furnace includes a preheater having an outlet through which fluid is exhausted and an inlet that receives fluids exhausted from the furnace and recirculated from the preheater outlet. In one embodiment, a cyclonic separator has an inlet in communication with the preheater outlet and an outlet in fluid communication with a fan. A controller controls the speed of the fan responsive to a drop in pressure between the separator inlet and outlet and a temperature at the separator outlet. In other embodiments, controllers control valves that (i) control the amount of fluids exhausted from the preheater that are delivered to a flue and recirculated to the preheater or (ii) control the amount of fluids diverted to charger for the furnace, in response to temperatures in a duct coupled to the preheater inlet.

Abstract: An apparatus for melting and refining a silica-based glass composition includes a vertical first reaction chamber having an input adjacent to a lower end for receiving glass-forming components. The glass-forming components are heated to elevated temperature during upward flow through the vertical first reaction chamber to form a glass precursor melt adjacent to an upper end of the vertical first reaction chamber. A vertical second reaction chamber has an input adjacent to an upper end and an output adjacent to a lower end for delivering glass melt. A cross passage connects the upper end of the vertical first reaction chamber to the upper end of the vertical second reaction chamber such that the precursor melt flows from the vertical first reaction chamber through the cross passage and then through the vertical second reaction chamber to homogenize the precursor melt.

Abstract: A process for making soda-lime glass includes forming and refining sodium silicate glass in liquid phase. At least one other material is dissolved in the refined liquid phase sodium silicate glass to produce a liquid phase soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with at least one other glass-forming material has the advantage of promoting release of gaseous reaction products from the sodium silicate glass during the refining step due at least in part to the relatively low viscosity of the sodium silicate glass. One or more steps in the process can be carried out under reduced pressure to promote release of gases and to reduce bubble formation.

Abstract: A process for making soda-lime glass includes calcining calcium carbonate in solid phase and at elevated temperature to form calcium oxide in solid phase and carbon dioxide gas. Sodium silicate glass is formed and refined separately in liquid phase. The solid phase calcium oxide is dissolved in the refined liquid phase sodium silicate glass to form a soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with calcium oxide has the advantage of promoting release of gaseous reaction products from the sodium silicate glass during the refining step due at least in part to the relatively low viscosity of the sodium silicate glass. One or more steps in the process can be carried out under reduced pressure to promote release of gases and to reduce bubble formation.

Abstract: A process for making silica-based glass includes: (a) forming a glass precursor melt that includes glass network formers and glass network modifiers, the glass precursor melt being at a temperature in the range of 900 C to 1700 C and having a viscosity of not more than 3 Pa·s, and (b) refining the glass precursor melt. Either or both steps (a) and (b) can include stirring and/or be carried out under reduced pressure to enhance refining. The refined glass precursor melt preferably is mixed with additional materials including silica (SiO2) to form a silica-based glass melt.

Abstract: A process for making silica-based glass includes: (a) forming a glass precursor melt that includes glass network formers and glass network modifiers, the glass precursor melt being at a temperature in the range of 900 C to 1700 C and having a viscosity of not more than 3 Pa·s, and (b) refining the glass precursor melt. Either or both steps (a) and (b) can include stirring and/or be carried out under reduced pressure to enhance refining. The refined glass precursor melt preferably is mixed with additional materials including silica (SiO2) to form a silica-based glass melt.

Abstract: A process for making soda-lime glass includes calcinating calcium carbonate in solid phase and at elevated temperature to form calcium oxide and release gases such as carbon dioxide. Sodium silicate glass is formed separately in liquid phase while releasing gaseous reaction products. The calcium oxide and the sodium silicate glass intermediate products are mixed in liquid phase to form a soda-lime glass melt. Formation of sodium silicate glass as an intermediate product before mixing with the calcium oxide has the advantage of promoting release of gaseous reaction products in the sodium silicate due at least in part to the relatively low viscosity of the sodium silicate glass. The calcination step and/or the sodium silicate-forming step and/or the final mixing step can be carried out under reduced pressure further to promote release of gases and reduce bubble formation.