High shear mixer and glass melting apparatus

• US 5,120,342 A
• Filed: 03/07/1991
• Issued: 06/09/1992
• Est. Priority Date: 03/07/1991
• Status: Expired due to Term

• Current Assignee: Stir-Melter Incorporated
• Original Assignee: Glasstech Incorporated
• Inventors: Richards, Ray S.
• Primary Examiner(s): Lindsay, Robert L.
• Application Number:
  US07/665,894
• Time in Patent Office: 460 Days
• Field of Search: 65/28, 65/27, 65/134, 65/178, 65/355, 65/347, 65/DIG. 4, 65/32.5, 65/135
• US Class Current: 65/178
• CPC Class Codes: B09B 3/0066 Disposal of asbestos
• CPC Class Codes: C03B 3/00 Charging the melting furnaces
• CPC Class Codes: C03B 5/005 of glass-forming waste materials disposal or transformation of solid waste in general B09B; treatment of radioactive waste G21F9/00
• 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 5/193 using gas, e.g. bubblers
• CPC Class Codes: C03B 5/225 Refining C03B5/18 takes precedence ; Refining agents C03C1/004
• CPC Class Codes: C03B 5/2252 under reduced pressure, e.g. with vacuum refiners
• CPC Class Codes: Y02P 40/50 Glass production, e.g. reusing waste heat during processing or shaping
• CPC Class Codes: Y10S 65/04 Electric heat

Abstract

A glass melter 30 having a mixing impeller 34 for converting a feed stream 38 supplied to a vessel 32 into a vitrified glass melt 50. Heating means such as electrodes 36 or a gas burner 58 are used to heat the glass melt 50. Electrode 36 arrangements are proposed for minimizing current flow through the impeller 34. Current flow through a special continuous circular impeller or conical pump 70 is disclosed. A cylindrical vessel 98, triangular vessel 94, square vessel 32, and hexagonal vessel 96 are disclosed. Methods of processing particular waste streams are disclosed including coated mineral fibers, fly ash, radioactive material, chemical waste and the like.

Claims

1. A melting apparatus for processing feed material comprising:

a vessel having an opening above an upper surface of a molten mineral material melt for contained in said vessel for receiving said feed material a portion of which is converted into molten mineral material in said vessel and an outlet port for removing molten mineral material from said vessel;

impeller means disposed in said vessel for dispersing feed material into said molten mineral material in said vessel;

a plurality of electrodes disposed in said vessel for passing electrical energy from one electrode to another through said molten mineral material in said vessel; and

power circuit means for electrically heating feed material and molten mineral material in said vessel, said power circuit means being electrically connected to said electrodes, said impeller means being essentially electrically isolated from said power circuit means.

2. The apparatus of claim 1 wherein suction means is operatively connected to a vessel for drawing a vacuum in said vessel and said porion of molten mineral material is subjected to a vacuum while in the vessel and wherein said portion of molten mineral material is degassed to remove seeds and other gaseous occlusions.

3. The apparatus of claim 1 wherein said impeller means is a frustoconical member having a first opening and a second opening smaller than said first opening, said first and second openings being aligned with a vertical axis of rotation, said second opening being submerged in said molten vitreous material and below said first opening which is disposed above the liquid level of said molten vitreous material.

4. The apparatus of claim 1 wherein said impeller means is an impeller disposed partially submerged in said molten vitreous material.

5. The apparatus of claim 4 wherein said impeller is formed of molybdenum and a reducing atmosphere is maintained in said vessel.

6. The apparatus of claim 4 wherein said impeller is formed of steel and includes cooling means for reducing the temperature of said impeller.

7. The apparatus of claim 4 wherein said cooling means is a water circulation system.

8. The apparatus of claim 4 wherein said cooling means is a steam circulation system.

9. The apparatus of claim 1 wherein said impeller means is a frustoconical member having a first opening and a second opening smaller than said first opening, said first and second openings being aligned with a vertical axis of rotation, said first and second openings being submerged in said molten vitreous material and said first opening being disposed below said second opening whereby said molten vitreous material is drawn down through said frustoconical member.

10. The apparatus of claim 1 wherein suction means is operatively connected to said vessel for drawing a vacuum in said vessel and said molten vitreous material are subjected to a vacuum in the vessel and wherein said molten vitreous material are degassed to remove seeds and other gaseous occlusions.

11. The apparatus of claim 1 wherein said impeller means is an impeller formed of steel and includes cooling means for reducing the temperature of said impeller, said impeller being wholly submerged in said molten vitreous material when operated and cooled for protection from melting.

12. The apparatus of claim 11 wherein said impeller includes cooling means for reducing the temperature of said impeller.

13. An apparatus for melting material comprising:

a vessel having an opening for receiving feed material, a portion of which is converted into molten mineral material in said vessel and an outlet port for removing molten mineral material from the vessel;

impeller means disposed in said vessel for mixing feed material and molten mineral material in said vessel; and

a plurality of electrodes disposed in said vessel introducing multi-phase power from one electrode to another through said molten mineral material in said vessel, each of said electrodes being connected to one phase of said multi-phase power and without introducing power through said impeller means.

14. The apparatus of claim 13 wherein said vessel is a hexagonal vessel and said electrodes are six in number with each electrode being disposed between said impeller and one of the corners of said vessel.

15. The apparatus of claim 13 wherein said vessel is a truncated equilateral triangle having three vertically extending sidewalls and three truncated corners, said electrodes being disposed in said corners with same phase electrodes being disposed in the same corner.

22. The apparatus of claim 13 wherein a three phase electrical current is provided to six electrodes and said impeller means has two blades, said six electrodes being arrayed so that said two blades are aligned with electrode pairs of identical phase whenever any of said two blades are aligned with any electrode.

23. The apparatus of claim 13 wherein a three phase electrical current is provided to nine electrodes and said impeller means has three blades, said nine electrodes being arrayed so that said three blades are aligned with sets of three electrodes of identical phase whenever any of said three blades are aligned with any electrode.

24. The apparatus of claim 13 wherein a two phase electrical current is provided to four electrodes and said impeller means has three blades, said four electrodes being arrayed so that said three blades are not aligned with any two electrodes at any time.

25. The apparatus of claim 13 wherein a two phase electrical current is provided to six electrodes and said impeller means has three blades, said six electrodes being arrayed so that said three blades are aligned with sets of three electrodes of identical phase whenever any of said three blades are aligned with any electrode.

26. The apparatus of claim 13 wherein a two phase electrical current is provided to eight electrodes and said impeller means has four blades, said eight electrodes being arrayed so that said four blades are aligned with sets of four electrodes of identical phase whenever any of said four blades are aligned with any electrode.

27. The apparatus of claim 13 wherein a single phase electrical current is provided to four electrodes and said impeller means has three blades, said four electrodes being arrayed so that said three blades are not aligned with any two electrodes at any time.

28. The apparatus of claim 13 wherein a single phase electrical current is provided to two electrodes and said impeller means has three blades, said two electrodes being arrayed so that two of said three blades are not aligned with said two electrodes at any time.

16. A melting apparatus for processing feed material comprising:

a vessel having an opening above an upper surface of a molten mineral material contained in said vessel for receiving said feed material thereon without forming a blanket over said upper surface, a portion of said feed material being converted into molten mineral material in said vessel and an outlet port for removing molten vitreous material from the vessel;

impeller means disposed in said vessel for mixing feed material into said molten mineral material in said vessel;

a plurality of electrodes disposed in said vessel for passing electrical energy from one electrode to another through said feed material and molten mineral material in said vessel; and

power circuit means for electrically heating molten vitreous material in said vessel, said power circuit means being electrically connected to said electrodes, wherein said power circuit means is not electrically connected to said impeller means.

17. The apparatus of claim 16 wherein said refractory vessel has a top cover which defines a controlled atmosphere space above the surface of said melt within said vessel.

18. The apparatus of claim 16 wherein said top cover of said vessel has a plurality of electrode receptacles in which said electrodes are supported in a downwardly depending relationship from said top cover through said controlled atmosphere space and into said molten vitreous material.

19. The apparatus of claim 16 wherein said vessel has walls formed of alumina zirconia silica refractory bricks having a known electrical resistance and said electrodes are spaced from said bricks sufficiently to minimize current flow through said bricks.

20. The apparatus of claim 16 wherein said vessel has walls formed of chrome refractory bricks having a known electrical resistance and said electrodes are spaced from said bricks sufficiently to minimize current flow through said bricks.

21. The apparatus of claim 16 wherein said electrodes spaced from said impeller means sufficiently to minimize current flow through said impeller means.