Submerged combustion melters having an extended treatment zone and methods of producing molten glass

Abstract

A submerged combustion melter includes a floor, a roof, and a sidewall structure connecting the floor and roof defining an internal space. A first portion of the internal space defines a melting zone, and a second portion defines a fining zone immediately downstream of the melting zone. One or more combustion burners in either the floor, roof, the sidewall structure, or any combination of these, are configured to emit the combustion gases from a position under a level of, and positioned to transfer heat to and produce, a turbulent molten mass of glass containing bubbles in the melting zone. The fining zone is devoid of combustion burners or other apparatus or components that would increase turbulence above that in the melting zone. The melter may include a treating zone that stabilizes or destabilizes bubbles and/or foam. Processes of using the melters are a feature of the disclosure.

What is claimed is: 
     
         1 . A submerged combustion melter comprising:
 a floor, a roof, and a sidewall structure connecting the floor and the roof and defining an internal space, a first portion of the internal space comprising a melting zone, and a second portion of the internal space defining a fining zone immediately downstream of the melting zone, a melting zone portion of the floor in the melting zone being horizontal at a first elevation and a fining zone portion of the floor in the fining zone being horizontal and at a second elevation different than the first elevation; and   one or more combustion burners in either the floor, the roof, the sidewall structure, or any two or more of these, producing combustion gases and configured to emit the combustion gases from a position under a level of, and positioned to transfer heat to and produce, a turbulent molten mass of glass containing bubbles in the melting zone;   wherein the submerged combustion melter comprises a geometry whereby the level of the molten glass is substantially equivalent in the melting zone and the fining zone, and the fining zone is devoid of combustion burners or other apparatus or components that would increase turbulence above that in the melting zone.   
     
     
         2 . The submerged combustion melter of  claim 1 , wherein at least some of the floor, the roof, and the sidewall structure comprise fluid-cooled panels. 
     
     
         3 . The submerged combustion melter of  claim 1 , further comprising a flow channel fluidly connected to the submerged combustion melter downstream of the fining zone. 
     
     
         4 . The submerged combustion melter of  claim 3 , wherein the flow channel is fluidly connected to the fining zone at a throat defined at least in part by the sidewall structure. 
     
     
         5 . The submerged combustion melter of  claim 4 , wherein the throat is disposed in the sidewall structure at a throat elevation less than the level of the molten glass in the fining zone. 
     
     
         6 . The submerged combustion melter of  claim 1 , further comprising a step disposed between the first portion of the internal space and the second portion of the internal space, wherein the step comprises a top elevation higher than the first elevation. 
     
     
         7 . The submerged combustion melter of  claim 1 , wherein the melting zone is defined by first portions of the floor, the roof, and the sidewall structure, and the fining zone is defined by second portions of the floor, the roof, and the sidewall structure forming a melter extension fluidly connected to the melting zone. 
     
     
         8 . The submerged combustion melter of  claim 1 , further comprising a feed zone upstream of the melting zone, the feed zone devoid of submerged combustion burners. 
     
     
         9 . The submerged combustion melter of  claim 1 , further comprising an exhaust stack positioned in the roof of the fining section. 
     
     
         10 . The submerged combustion melter of  claim 1 , further comprising an exhaust stack positioned in the roof of the fining section. 
     
     
         11 . A method comprising:
 charging a feed composition into a submerged combustion melter, at least a portion of the feed composition comprising a vitrifiable material;   heating the feed composition with one or more submerged combustion burners, thereby melting at least a portion of the vitrifiable material in a melting zone of the submerged combustion melter to form a turbulent molten mass of glass and bubbles in the melting zone;   allowing the turbulent molten mass of glass and bubbles to flow into a fining zone in the submerged combustion melter downstream of the melting zone, the fining zone devoid of submerged combustion burners and other apparatus or components that would increase turbulence above that in the melting zone, thus forming a fined molten mass of glass having foam on an upper surface thereof; and   maintaining a substantially equal level of molten glass in the melting zone and the fining zone, wherein the melter comprises a floor in the melting zone being substantially horizontal and a floor in the fining zone disposed below the substantially horizontal floor in the melting zone.   
     
     
         12 . The method of  claim 11 , further comprising allowing the turbulent molten mass of glass and bubbles to flow into a flow channel downstream of the fining zone, wherein the turbulent molten mass of glass and bubbles flows into the flow channel via a throat disposed in a sidewall of the submerged combustion melter below the upper surface of the turbulent molten glass in the melting zone and fining zone. 
     
     
         13 . The method of  claim 12 , wherein allowing the turbulent molten mass of glass and bubbles to flow into the flow channel retains at least a portion of the foam on the upper surface of the fined molten mass of glass in the fining zone. 
     
     
         14 . The method of  claim 11 , further comprising allowing the turbulent molten mass of glass and bubbles to flow from the melting zone, over a step, and into the fining zone, wherein a top surface of the step is disposed at an elevation higher than the floor of the melting zone. 
     
     
         15 . The method of  claim 11 , further comprising allowing the turbulent molten mass of glass and bubbles to flow into a treating zone devoid of submerged combustion burners and other apparatus or components that would increase turbulence above that in the melting zone, thus forming a less turbulent molten mass of glass containing bubbles in the treating zone, the treating zone immediately downstream of the melting zone and immediately upstream of the fining zone. 
     
     
         16 . The method of  claim 15 , further comprising injecting a treating composition into the less turbulent molten mass of glass containing bubbles in the treating zone using one or more non-burner apparatus, thus forming a treated molten mass of glass having foam on an upper surface thereof. 
     
     
         17 . The method of  claim 16 , further comprising decreasing the stability of the bubbles using the treating condition. 
     
     
         18 . The method of  claim 11 , wherein the charging of a feed composition into a submerged combustion melter comprising a geometry comprises feeding a feed zone upstream of the melting zone, the feed zone devoid of submerged combustion burners. 
     
     
         19 . The method of  claim 11 , further comprising exhausting the submerged combustion melter employing an exhaust stack positioned in the roof of the fining zone. 
     
     
         20 . The method of  claim 11 , further comprising exhausting the submerged combustion melter employing an exhaust stack positioned in the roof of the melting zone.