High temperature and low pressure fining of submerged combustion or other glass

Patent metadata

Field	Value
Publication number	US-12459848-B2
Application number	US-202218550319-A
Country	US
Kind code	B2
Filing date	Apr 26, 2022
Priority date	Apr 30, 2021
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A method of producing glass includes discharging an outflow ( 22, 1022 ) of fined molten glass from a fining tank ( 18, 1018 ) of a vacuum induction fining apparatus ( 10, 1010 ) and delivering the fined molten glass into a thermal conditioning tank ( 16, 1016 ) that is separated from the fining tank by an open space ( 26, 1026 ) occupied by an ambient environment ( 24, 1024 ). The fining tank includes a vertically-elongated housing ( 80, 1080 ) that defines an interior fining chamber ( 82, 1082 ) where a bath ( 76, 1076 ) of molten glass is collected and maintained. The interior fining chamber is maintained at subatmospheric pressure and the housing is surrounded by at least one induction coil ( 74, 1074 ) to introduce heat into the molten glass bath. The vacuum maintained in the interior fining chamber and the heating supplied by the induction coil(s) promote the ascension of gas bubbles upwards through the molten glass bath. A glass-producing system that includes the vacuum induction fining apparatus is also disclosed.

First claim

The invention claimed is:

1 . A method of producing glass, the method comprising:
producing a volume of unfined molten glass that comprises at least 20 vol % of entrained gas bubbles; receiving an inflow of unfined molten glass from the volume of unfined molten glass and introducing the inflow of unfined molten glass into a fining tank that holds a molten glass bath, the fining tank having a housing that defines an interior fining chamber in which the molten glass bath is contained, the housing of the fining tank having a height and a width, with the height of the housing being greater than the width of the housing, the inflow of unfined molten glass combining with the molten glass bath in the interior fining chamber of the fining tank; maintaining the interior fining chamber of the fining tank at a subatmospheric pressure; inductively heating the molten glass bath contained within the fining tank to maintain the molten glass bath within a temperature range for glass fining; discharging an outflow of fined molten glass from the fining tank, the outflow of fined molten glass being drawn from the molten glass bath and having a lower volume percentage of entrained gas bubbles and a higher density than the inflow of unfined molten glass received into the fining tank; passing the outflow of fined molten glass through an ambient environment as the outflow of fined molten glass falls from the fining tank into a thermal conditioning tank through an open space that separates the fining tank and the thermal conditioning tank, the outflow of fined molten glass cooling down when exposed to the ambient environment; introducing the outflow of fined molten glass into the thermal conditioning tank in which the outflow of fined molten glass combines with a flowing molten glass bath held within a conditioning chamber of the thermal conditioning tank; and discharging an output of conditioned molten glass from the thermal conditioning tank, the output of conditioned molten glass having a temperature that is less than a temperature of the outflow of fined molten glass introduced into the thermal conditioning tank.

2 . The method set forth in claim 1 , wherein producing unfined molten glass comprises:
introducing a vitrifiable feedstock material into an interior reaction chamber of a submerged combustion melter that holds a glass melt comprising the volume of unfined molten glass; and discharging combustion products from one or more submerged combustion melters directly into the glass melt held to heat and agitate the glass melt as the vitrifiable feedstock material melt-reacts within the glass melt to form unfined molten glass.

3 . The method set forth in claim 1 , wherein the volume of unfined molten glass that is produced has a soda-lime-silica glass chemical composition comprising 60 wt % to 80 wt % SiO 2 , 8 wt % to 18 wt % Na2O, and 5 wt % to 15 wt % CaO.

4 . The method set forth in claim 3 , wherein the inflow of unfined molten glass comprises 30 vol % to 60 vol % of entrained gas bubbles and has a density of 0.75 gm/cm3 to 1.5 gm/cm3, and wherein the outflow of fined molten glass comprises 0 vol % to 0.1 vol % of entrained gas bubbles and has a density of 2.3 gm/cm3 to 2.5 gm/cm3.

5 . The method set forth in claim 1 , wherein the outflow of fined molten glass includes one or more discrete streams of fined molten glass.

6 . The method set forth in claim 5 , wherein the outflow of fined molten glass includes three to five discrete streams of fined molten glass.

7 . The method set forth in claim 1 , wherein the molten glass bath held within the interior fining chamber of the fining tank is maintained at a uniform temperature.

8 . The method set forth in claim 1 , wherein a temperature gradient is established within the molten glass bath held within the interior fining chamber of the fining tank such that the temperature of the molten glass bath increases along a depth of the molten glass bath.

9 . The method set forth in claim 1 , wherein the fining tank is surrounded by a pressure shell that defines an interior containment chamber, the interior containment chamber fluidly communicating with the interior fining chamber of the fining tank located therein, and wherein maintaining the subatmospheric pressure of the interior fining chamber comprises maintaining the interior containment chamber at a subatmospheric pressure.

10 . The method set forth in claim 1 , wherein the outflow of fined molten glass is drawn from a lowermost 25% of the depth of the molten glass bath held within the interior fining chamber of the fining tank.

11 . A method of producing glass, the method comprising:
producing a volume of unfined molten glass in a submerged combustion melter which includes discharging combustion products from one or more submerged burners directly into a glass melt held within an interior reaction chamber of the submerged combustion melter; receiving an inflow of unfined molten glass from the submerged combustion melter and introducing the inflow of unfined molten glass into a fining tank that holds a molten glass bath having a depth, the fining tank having a vertically-elongated housing that defines an interior fining chamber in which the molten glass bath is contained, the housing of the fining tank having a height and a width, with the height of the housing being greater than the width of the housing, the inflow of unfined molten glass combining with the molten glass bath in the interior fining chamber of the fining tank; maintaining the interior fining chamber of the fining tank at a subatmospheric pressure; inductively heating the molten glass bath contained within the fining tank to maintain the molten glass bath at a temperature ranging from 1250° C. to 1650° C.; discharging an outflow of fined molten glass from the fining tank, the outflow of fined molten glass being drawn from the molten glass bath and having a lower volume percentage of entrained gas bubbles and a higher density than the inflow of unfined molten glass received into the fining tank, the outflow of fined molten glass being in the form of a plurality of discrete streams of fined molten glass; passing the outflow of fined molten glass through an ambient environment as the outflow of fined molten glass falls from the fining tank into a thermal conditioning tank through an open space that separates the fining tank and the thermal conditioning tank, the outflow of fined molten glass cooling down when exposed to the ambient environment; and introducing the outflow of fined molten glass into the thermal conditioning tank in which the outflow of fined molten glass combines with a flowing molten glass bath held within a conditioning chamber of the thermal conditioning tank.

12 . The method set forth in claim 11 , further comprising:
discharging an output of conditioned molten glass from the thermal conditioning tank, the output of conditioned molten glass having a temperature that is less than a temperature of the outflow of fined molten glass introduced into the thermal conditioning tank.

13 . The method set forth in claim 11 , wherein inductively heating the molten glass bath held within the interior fining chamber comprises:
controlling one or more induction heating coils that surround the interior fining chamber to maintain the molten glass bath held within the interior fining chamber at a uniform temperature.

14 . The method set forth in claim 11 , wherein inductively heating the molten glass bath held within the interior fining chamber comprises:
separately controlling a plurality of sets of one or more induction heating coils arranged serially aro

Assignees

• Owens Brockway Glass Container

Inventors

• Wang Zhongming
• Shi Liming
• Jiang Qing

Classifications

• C03B5/235

  Heating the glass (C03B5/02, C03B5/18, C03B5/225 take precedence) · CPC title

• C03B5/12

  in shaft furnaces {(C03B5/02 takes precedence)} · CPC title

• C03B5/262

  Drains, i.e. means to dump glass melt or remove unwanted materials · CPC title

• C03B5/193

  using gas, e.g. bubblers · CPC title

• C03C3/087

  containing calcium oxide, e.g. common sheet or container glass · CPC title