Processes for producing molten glasses from glass batches using turbulent submerged combustion melting, and systems for carrying out such processes

Abstract

Processes and systems for producing molten glass using submerged combustion melters, including densifying an initial composition comprising vitrifiable particulate solids and interstitial gas to form a densified composition comprising the solids by removing a portion of the interstitial gas from the composition. The initial composition is passed from an initial environment having a first pressure through a second environment having a second pressure higher than the first pressure to form a composition being densified. Any fugitive particulate solids escaping from the composition being densified are captured and recombined with the composition being densified to form the densified composition. The densified composition is fed into a feed inlet of a turbulent melting zone of a melter vessel and converted into turbulent molten material using at least one submerged combustion burner in the turbulent melting zone.

What is claimed is: 
     
         1 . A process comprising:
 a) densifying an initial composition comprising vitrifiable particulate solids and interstitial gas to form a densified composition comprising the solids by removing a portion of the interstitial gas from the composition by
 i) passing the initial composition from an initial environment having a first pressure through a second environment having a second pressure higher than the first pressure to form a composition being densified, and 
 ii) capturing any fugitive particulate solids escaping from the composition being densified and recombining the fugitive particulate solids with the composition being densified to form the densified composition; 
   b) feeding the densified composition into a feed inlet of a turbulent melting zone of a melter vessel; and   c) converting the densified composition into turbulent molten material using at least one submerged combustion burner in the turbulent melting zone.   
     
     
         2 . The process of  claim 1  wherein the passing of the initial composition from the initial environment through the second environment comprises passing the initial composition into a processing unit comprising a recirculation section, the processing unit selected from the group consisting of a compacting screw feeder, one or more pairs of compacting rolls, one or more briquetting rolls, and one or more roll presses. 
     
     
         3 . The process of  claim 1  wherein the densifying comprises using a screw feeder having a number of sections arrayed in succession along its length so as to subject the initial composition to a succession of operations, including drawing the initial composition from a source chamber into a feed section of the screw feeder extending into the source chamber, drawing the initial composition from the feed section into a feed seal section adjacent the feed section, conveying the initial composition through a conveying section adjacent the feed seal section, passing the initial composition through a recirculation section adjacent the conveying section, passing the initial composition through a high pressure section to form the composition being densified, and confining any fugitive particulate solids blown out of the high pressure section from the composition being densified in a recirculation chamber through which the screw feeder extends and recombining the fugitive particulate solids with the composition being densified to form the densified composition, the recirculation chamber further enclosing the conveying section and the recirculation section. 
     
     
         4 . The process of  claim 3  comprising:
 shrouding the feed seal section of the screw feeder with a feed seal section shroud, 
 shrouding the high pressure section with a high pressure section shroud closely surrounding the high pressure section, the high pressure section of the screw feeder having an output end through which the densified composition emerges, 
 permitting the composition being densified by the high pressure section to emerge under pressure from the high pressure shroud and move against a hingedly mounted preloaded cover in yieldable sealing engagement with the output end of the high pressure shroud, and 
 conveying the densified composition into the feed inlet of the melting zone of the melter vessel. 
 
     
     
         5 . The process of  claim 4  comprising flowing the densified composition emerging from the output chute down a sloping chute attached to the output end of the high pressure shroud to prevent free-fall of the emerging densified composition. 
     
     
         6 . The process of  claim 4  comprising shrouding downstream of the high pressure section of the screw feeder using a portion of the high pressure shroud so that the composition being densified in that portion tends to act as a seal between the high pressure section and the output end of the high pressure shroud. 
     
     
         7 . The process of  claim 4  comprising shrouding upstream of the high pressure section into the recirculation chamber using a portion of the high pressure shroud. 
     
     
         8 . The process of  claim 7  comprising venting the portion of the high pressure shroud using a large number of perforations. 
     
     
         9 . The process of  claim 1  comprising increasing temperature of the composition being densified during the densifying to release bound water from some of the composition being densified, and using the released bound water as a binding agent to maintain compaction of the composition being densified. 
     
     
         10 . The process of  claim 1  comprising decreasing pressure of the composition being densified during the densifying to increase rate of compaction. 
     
     
         11 . A process comprising:
 a) densifying an initial composition comprising vitrifiable particulate solids and interstitial gas to form a densified composition comprising the solids by removing a portion of the interstitial gas from the composition, the densifying comprising:
 i) removing air from the initial composition stored in a source chamber, the removing comprising: 
 ii) subjecting the initial composition to a succession of operations in a plurality of sections of a screw feeder having a shaft and a thread, including 
 iii) drawing the initial composition from the source chamber into a feeding section of the screw feeder extending into the source chamber; 
 iv) drawing the initial composition from the feeding section into a feed seal section adjacent the feeding section; 
 v) conveying the initial composition through a conveying section adjacent the feed seal section; 
 vi) passing the initial composition through a recirculation section adjacent the conveying section; 
 vii) passing the initial composition through a high pressure section adjacent the conveying section to form a composition being densified and ultimately the densified composition; 
 viii) confining particulate solids blown out of the high pressure section of the screw feeder as the composition being densified is compressed thereby in a recirculation chamber through which the screw feeder extends, the recirculation chamber further enclosing the conveying section and the recirculation section; 
   b) feeding the densified composition into a feed inlet of a turbulent melting zone of a melter vessel;   c) converting the densified composition into turbulent molten material using at least one burner directing combustion products into the turbulent melting zone under a level of the turbulent molten material in the turbulent melting zone, one or more of the burners imparting turbulence to the turbulent molten material in the turbulent melting zone;   d) passing the turbulent molten material through a melter exit structure to form a less turbulent or non-turbulent molten material; and   e) discharging the less turbulent or non-turbulent molten material from the melter vessel.   
     
     
         12 . The process of  claim 11  wherein the feed seal section has a screw pitch, the feeding section has a screw pitch, the process comprising configuring the seal section screw pitch to be the same as the feeding section screw pitch. 
     
     
         13 . The process of  claim 11  wherein the conveying section has a screw pitch, the feeding section has a screw pitch, the process comprising configuring the conveying section screw pitch to be greater than the screw pitch of the feeding section. 
     
     
         14 . The process of  claim 11  wherein the recirculation section has a screw pitch, the conveying section has a screw pitch, the process comprising configuring the screw pitch of the recirculation section to be substantially the same as the pitch of the conveying section. 
     
     
         15 . The process of  claim 11  wherein the high pressure section has a screw pitch, the recirculation section has a screw pitch, the process comprising configuring the screw pitch of the high pressure section to be substantially the same as the pitch of the recirculation section. 
     
     
         16 . The process of  claim 11  comprising:
 shrouding the feed seal section of the screw feeder with a feed seal section shroud, 
 shrouding the high pressure section with a high pressure section shroud closely surrounding the high pressure section, the high pressure section of the screw feeder having an output end through which the composition being densified emerges, 
 permitting the composition being densified by the high pressure section to emerge under pressure from the high pressure shroud and move against a hingedly mounted preloaded cover in yieldable sealing engagement with the output end of the high pressure shroud, thus forming the densified composition, and 
 conveying the densified composition into the feed inlet of the turbulent melting zone of the melter vessel. 
 
     
     
         17 . The process of  claim 16  comprising flowing the densified composition emerging from the output end down a sloping chute attached to the output end to prevent free-fall of the emerging densified composition. 
     
     
         18 . The process of  claim 16  comprising shrouding downstream of the high pressure section of the screw feeder using a portion of the high pressure shroud so that the composition being densified in that portion tends to act as a seal between the high pressure section and the output end of the high pressure shroud. 
     
     
         19 . The process of  claim 16  comprising shrouding upstream of the high pressure section into the recirculation chamber using a portion of the high pressure shroud. 
     
     
         20 . The process of  claim 19  comprising venting the portion of the high pressure shroud using a large number of perforations. 
     
     
         21 . The process of  claim 11  comprising wherein the recirculation chamber has walls that extend upward from opposite sides of the screw feeder, the walls not diverging upwardly. 
     
     
         22 . The process of  claim 11  comprising increasing capacity of the feeding section of the screw feeder in direction of draw. 
     
     
         23 . The process of  claim 22  comprising increasing thread pitch of the screw feeder in the direction of draw in the feeding section to produce an increase in capacity in that direction. 
     
     
         24 . The process of  claim 22  comprising decreasing shaft diameter of the screw feeder in the feeding section in the direction of draw to produce an increase in capacity in that direction. 
     
     
         25 . The process of  claim 11  comprising increasing capacity in the direction of draw in the conveying section of the screw feeder. 
     
     
         26 . The process of  claim 25  comprising increasing thread pitch of the screw feeder in the conveying section in the direction of draw to produce the increase in capacity in that direction. 
     
     
         27 . The process of  claim 25  comprising decreasing shaft diameter of the screw feeder in the conveying section in the direction of draw to produce an increase in capacity in that direction. 
     
     
         28 . The process of  claim 11  comprising injecting a gas other than air into a space adjacent the recirculation section of the screw feeder. 
     
     
         29 . The process of  claim 11  comprising injecting a gas other than air into a space adjacent the conveying section of the screw feeder.