METHOD FOR RAPIDLY MELTING AND REFINING GLASS

• US 3,819,350 A
• Filed: 09/28/1972
• Issued: 06/25/1974
• Est. Priority Date: 09/28/1972
• Status: Expired due to Term

• Current Assignee: Kimble Glass, Inc. (Corning Incorporated)
• Original Assignee: Fred G. Pellett, Paul R. Wengert, Raymond S. Richards, Robert R. Rough, St. John, Douglas F.
• Inventors: Richards, Raymond S., Rough, Robert R., Pellett, Fred G., St. John, Douglas F., Wengert, Paul R.
• Primary Examiner(s): Bashore, S. Leon
• Assistant Examiner(s): Schor, Kenneth M.
• Application Number:
  US05/292,991
• Time in Patent Office: 635 Days
• Field of Search: 65/134,178,135 13/6 55/199
• US Class Current: 65/134.9
• CPC Class Codes: C03B 3/005 using screw feeders
• CPC Class Codes: C03B 5/00 Melting in furnaces; Furnaces so far as specially adapted for glass manufacture
• CPC Class Codes: C03B 5/027 by passing an electric current between electrodes immersed in the glass bath, i.e. by direct resistance heating
• CPC Class Codes: C03B 5/187 with moving elements
• CPC Class Codes: C03B 5/1875 of the screw or pump-action type
• CPC Class Codes: C03B 5/2255 by centrifuging

Abstract

In accordance with the method of this invention, glass-forming materials are subjected to heat and agitation sufficient to form a molten glass having some undissolved glass-forming materials, cords, and incompleted chemical reactions between the glassforming materials and containing a high number of gaseous inclusions. This molten glass is subjected to a shearing action to complete the melting of any unmelted sand grains remaining from the glass-forming materials, and to complete the chemical reactions that may have been incomplete, and to remove any cords remaining but leave the glass with gaseous inclusions; this glass is thereafter subjected to centrifugal forces sufficient to remove the gaseous inclusions and thereby produce a refined molten glass having the desired homogeneity. In one embodiment of the invention, glass-forming materials are introduced into a first chamber wherein they are subjected to heat and agitation sufficient to form a molten glass having some undissolved glassforming materials, cords, and incompleted chemical reactions between the glass-forming materials and containing a high number of gaseous inclusions. This glass is introduced into a second chamber, where it is subjected to a shearing action to remove remaining inhomogeneities and complete the melting of the glass; this molten, homogenized glass containing gaseous inclusions is introduced to a third chamber where it is subjected to centrifugal forces sufficient to remove the gaseous inclusions, producing a refined, homogeneous molten glass, which is discharged from the third chamber.

Claims

1. A method of making glass which comprises applying heat to glass-forming materials to produce a mass of molten glass, mixing glass-forming materials in the molten glass, agitating the mixture of glass-forming materials and molten glass, and applying heat to said mixture, continuing the mixing, agitation and application of heat for a time such as to disperse the materials rapidly and uniformly in the mass of molten glass, facilitate transfer of heat to the materials and promote rapid chemical reactions until a molten glass is produced which has some undissolved glass-forming materials, cords, and incompleted chemical reactions between the glass-forming materials and contains gaseous inclusions, thereafter subjecting such molten glass having some undissolved glass-forming materials, cords, and incompleted chemical reactions and containing gaseous inclusions to a shearing action, continuing the shearing action until the undissolved glass-forming materials are substantially dissolved, undesirable cords are removed, and chemical reactions are substantially completed, leaving the molten glass in a homogenized state having gaseous inclusions therein, thereafter rotating the homogenized molten glass containing gaseous inclusions, continuing the rotation for a time and at a speed such as to produce pressure gradients within the glass to cause gaseous inclusions to migrate out of the glass and thereby produce a refined molten glass having a controlled number of gaseous inclusions.

2. The method set forth in claim 1 including the step of applying heat to said glass melt during said step of shearing.

3. The method set forth in claim 1 including the step of subjecting the glass to a temperature conditioning step between the step of shearing and the step of rotating.

4. The method of making glass which comprises heating glass-forming materials to produce a mass of molten glass, substantially continuously delivering glass-forming materials to said mass of molten glass, mixing said glass-forming materials in the molten glass, agitating the mixture of glass-forming materials and the molten glass and applying heat, continuing the mixing, agitating, and application of heat for a time such as to rapidly disperse the glass-forming materials in the molten glass and facilitate heat transfer to the materials and promote rapid chemical reactions to produce molten glass, which molten glass has some undissolved glass-forming materials, cords, and incompleted chemical reactions between the glass-forming materials and contains gaseous inclusions, continuously removing said molten glass having some undissolved glass-forming materials, cords, and incompleted chemical reactions and containing gaseous inclusions from said heated aNd agitated mass of glass, subjecting the molten glass removed from the mass being heated and agitated to a shearing action by moving the glass between relatively moving surfaces, and continuing the shearing action until molten glass is produced which has the glass-forming materials substantially dissolved, the undesirable cords removed, the chemical reactions substantially completed so that the molten glass is homogeneous and contains gaseous inclusions, continuously removing the homogeneous molten glass containing gaseous inclusions, continuously rotating such homogeneous molten glass containing gaseous inclusions, and continuing rotation for a time and at a speed to produce pressure gradients within the glass until the molten glass has a controlled number of gaseous inclusions, and thereafter continuously removing such refined molten glass with a controlled number of gaseous inclusions.

5. The method set forth in claim 4 including the step of applying heat to said glass melt during said step of shearing.

6. The method set forth in claim 4 including the step of subjecting the glass to a temperature conditioning step between the step of shearing and the step of rotating the molten glass.

7. The method of making glass which comprises heating glass-forming materials in a first chamber to produce a mass of molten glass, substantially continuously delivering glass-forming materials to said mass of molten glass in said first chamber, mixing said glass-forming materials in the molten glass, agitating the mixture of said glass-forming materials and molten glass, and applying heat, continuing the mixing agitation and application of heat for a time such as to rapidly disperse the glass-forming materials in the molten glass and facilitate heat transfer and promote rapid chemical reactions to produce molten glass, which molten glass has some undissolved glass-forming materials, cords, and incompleted chemical reactions between the glass-forming materials and contains gaseous inclusions, continuously removing said molten glass having some undissolved glass-forming materials, cords, and incompleted chemical reactions and containing gaseous inclusions from said first chamber, subjecting the molten glass removed from the mass being heated and agitated to a shearing action in a second chamber by moving the glass between relatively moving surfaces, and continuing the shearing action until molten glass is produced which has the glass-forming materials substantially dissolved, the undesirable cords removed, the chemical reactions substantially completed so that the molten glass is homogeneous and contains gaseous inclusions, continuously removing the homogeneous molten glass containing gaseous inclusions from said second chamber and delivering said glass to a third chamber, continuously rotating such molten glass containing gaseous inclusions in said third chamber, and continuing rotation for a time and at a speed to produce pressure gradients within the glass to cause the gaseous inclusions to migrate out of the glass until the molten glass has a controlled number of gaseous inclusions, and thereafter continuously removing such refined molten glass with a controlled number of gaseous inclusions from said third chamber.

8. The method set forth in claim 7 including the step of subjecting said glass in said second chamber to heat.

9. The method set forth in claim 7 including the step of subjecting said glass which is removed from said second chamber to a temperature conditioning step before it is introduced into said third chamber.