Glass manufacturing apparatuses and methods for operating the same

Abstract

In embodiments, a method for operating a glass manufacturing apparatus may include heating a delivery conduit with resistive windings positioned around an exterior surface of the delivery conduit, the delivery conduit extending between a mixing vessel and a delivery vessel. The method may also include injecting electric current through the delivery conduit while heating the delivery conduit with resistive windings and prior to flowing molten glass through the delivery conduit thereby increasing a temperature of the of the delivery conduit, wherein an input heat flux into the delivery conduit is greater than an output heat flux away from the delivery conduit prior to flowing molten glass through the delivery conduit.

What is claimed is: 
     
         1 . A method for operating a glass manufacturing apparatus, the method comprising:
 heating a delivery conduit with resistive windings positioned around an exterior surface of the delivery conduit, the delivery conduit extending between a first vessel and a second vessel; and   injecting electric current through the delivery conduit while heating the delivery conduit with the resistive windings and prior to flowing molten glass through the delivery conduit thereby increasing a temperature of the of the delivery conduit,   wherein an input heat flux into the delivery conduit is greater than an output heat flux away from the delivery conduit prior to flowing molten glass through the delivery conduit.   
     
     
         2 . The method of  claim 1 , further comprising:
 flowing molten glass from the first vessel to the second vessel through the delivery conduit;   heating the delivery conduit with the resistive windings as the molten glass flows through the delivery conduit; and   discontinuing the injection of electric current through the delivery conduit as the molten glass flows through the delivery conduit.   
     
     
         3 . The method of  claim 2 , further comprising:
 intermittently injecting electric current through the delivery conduit as the molten glass flows through the delivery conduit.   
     
     
         4 . The method of  claim 3 , further comprising:
 measuring a temperature of the delivery conduit as molten glass flows through the delivery conduit; and   injecting electric current through the delivery conduit when a temperature of the delivery conduit is less than a threshold temperature.   
     
     
         5 . The method of  claim 3 , further comprising:
 monitoring a flow rate of molten glass through the glass manufacturing apparatus; and   injecting electric current through the delivery conduit when the flow rate of molten glass through the glass manufacturing apparatus is less than a baseline flow rate.   
     
     
         6 . The method of  claim 3 , further comprising:
 forming the molten glass into a glass ribbon with the glass manufacturing apparatus;   detecting, automatically with a flaw detection system, flaws in the glass ribbon; and   injecting electric current through the delivery conduit when flaws are detected in the glass ribbon with the flaw detection system.   
     
     
         7 . The method of  claim 3  further comprising:
 monitoring electric current passing through the resistive windings; and 
 increasing the electric current through the delivery conduit when the electric current is less than a threshold electric current value. 
 
     
     
         8 . The method of  claim 1 , wherein:
 the second vessel comprises a downstream electrode electrically coupled to the delivery conduit; and   the first vessel comprises an upstream electrode electrically coupled to the delivery conduit, wherein the upstream electrode, the delivery conduit, and the downstream electrode are electrically coupled in a closed-loop circuit.   
     
     
         9 . The method of  claim 2 , wherein the first vessel comprises a mixing vessel and the second vessel comprises a delivery vessel. 
     
     
         10 . The method of  claim 9 , wherein the delivery vessel is fluidly coupled to a forming vessel. 
     
     
         11 . A glass manufacturing apparatus comprising:
 a mixing vessel comprising an upstream electrode;   a delivery vessel comprising a downstream electrode;   a delivery conduit connecting the mixing vessel to the delivery vessel, the delivery conduit comprising resistive windings positioned around an exterior surface of the delivery conduit;   a first power source electrically coupled to the resistive windings;   a second power source electrically coupled to the delivery conduit in a closed-loop circuit;   an electronic control unit communicatively coupled to the first power source and the second power source and comprising a processor and a non-transient memory storing a computer readable and executable instruction set which, when executed by the processor:
 actuates the first power source thereby heating the delivery conduit with the resistive windings; and 
 prior to flowing molten glass through the delivery conduit, actuates the second power source thereby injecting electric current through the delivery conduit while heating the delivery conduit with the resistive windings and increasing a temperature of the delivery conduit, wherein an input heat flux into the delivery conduit is greater than an output heat flux away from the delivery conduit prior to flowing molten glass through the delivery conduit. 
   
     
     
         12 . The glass manufacturing apparatus of  claim 11 , wherein the computer readable and executable instruction set, when executed by the processor, discontinues the injection of electric current through the delivery conduit with the second power source when molten glass is flowing through the delivery conduit. 
     
     
         13 . The glass manufacturing apparatus of  claim 11 , wherein the computer readable and executable instruction set, when executed by the processor, intermittently actuates the second power source thereby intermittently injecting electric current through the delivery conduit as the molten glass flows through the delivery conduit. 
     
     
         14 . The glass manufacturing apparatus of  claim 13 , further comprising at least one thermocouple operatively associated with the delivery conduit and communicatively coupled to the electronic control unit, the at least one thermocouple positioned to detect a temperature of the delivery conduit, wherein the computer readable and executable instruction set, when executed by the processor, actuates the second power source thereby injecting electric current through the delivery conduit when a temperature of the delivery conduit is less than a threshold temperature. 
     
     
         15 . The glass manufacturing apparatus of  claim 14 , further comprising a flow rate monitor communicatively coupled to the electronic control unit, the flow rate monitor detecting a flow rate of molten glass through the glass manufacturing apparatus, wherein the computer readable and executable instruction set, when executed by the processor, actuates the second power source thereby injecting electric current through the delivery conduit when the flow rate of molten glass through the glass manufacturing apparatus is less than a baseline flow rate. 
     
     
         16 . The glass manufacturing apparatus of  claim 14 , further comprising a flaw detection system communicatively coupled to the electronic control unit, the flaw detection system detecting flaws in a glass ribbon formed with the glass manufacturing apparatus, wherein the computer readable and executable instruction set, when executed by the processor, actuates the second power source thereby injecting electric current through the delivery conduit when flaws are detected in the glass ribbon with the flaw detection system. 
     
     
         17 . The glass manufacturing apparatus of  claim 14 , further comprising at least one ammeter electrically coupled to the resistive windings and communicatively coupled to the electronic control unit, the ammeter detecting electric current passing through the resistive windings, wherein the computer readable and executable instruction set, when executed by the processor, actuates the second power source thereby injecting electric current through the delivery conduit when electric current through the resistive windings is less than a threshold electric current value. 
     
     
         18 . The glass manufacturing apparatus of  claim 11 , wherein:
 the delivery vessel comprises a downstream electrode electrically coupled to the delivery conduit; and   the mixing vessel comprises an upstream electrode electrically coupled to the delivery conduit, wherein the closed-loop circuit includes the upstream electrode, the delivery conduit, and the downstream electrode.   
     
     
         19 . The glass manufacturing apparatus of  claim 11 , wherein the delivery vessel is fluidly coupled to a fusion-forming vessel. 
     
     
         20 . The glass manufacturing apparatus of  claim 11 , wherein electric current is injected into the closed-loop circuit through the downstream electrode.