High shear mixer and glass melting apparatus and method

• US 5,273,567 A
• Filed: 04/02/1992
• Issued: 12/28/1993
• 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 JR, ROBERT
• Application Number:
  US07/862,328
• Time in Patent Office: 635 Days
• Field of Search: 65/27, 65/28, 65/134, 65/135, 65/136, 65/178, 65/347, 65/355, 65/DIG. 4, 65/32.5, 252/629
• US Class Current: 65/134.8
• 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

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 method of vitrifying radioactive material including combustible components and non-combustible components comprising the steps of:

depositing said radioactive material directly in a molten glass bath;

oxidizing combustible components of said radioactive material by contact with the molten glass bath;

stirring the molten glass bath with an impeller;

dispersing combustible components and non-combustible components of said radioactive material in the molten glass bath to form a solution thereof in the molten glass bath; and

removing a portion of said molten glass bath from said vessel.

2. The method of claim 1 further comprising the step of injecting an oxidizing agent into the vessel to facilitate oxidizing the organic components of the radioactive material.

3. The method of claim 1 wherein said portion of said glass melt removed from said vessel is further processed by the step of additionally heating said portion in a second vessel.

4. The method of claim 1 wherein said second stage is a molten bath having no agitation except for convection currents within the bath.

5. The method of vitrifying radioactive material including combustible components and non-combustible components comprising the steps of:

depositing said radioactive material directly into a vessel containing a molten glass bath;

oxidizing combustible components of said radioactive material in said vessel;

supplying glass formers, glass modifiers and fluxing agents to the molten glass bath;

blending combustible components and non-combustible components with the added glass formers, glass modifiers and fluxing agents in the molten glass bath to form a radioactive molten glass bath; and

removing a portion of said radioactive molten glass bath.

6. The method of claim 5 including the further step of supplying said radioactive material to the vessel in the form of an aqueous slurry.

7. The method of claim 6 including the further step of pre-processing said aqueous slurry prior to adding the aqueous slurry to the vessel, said preprocessing including removing undesirable components from the slurry.

8. The method of claim 5 wherein the step of removing a portion of the radioactive waste molten glass bath includes the additional step of tapping the vessel at a point spaced above the bottom of the vessel wherein heavy material is permitted to accumulate in the bottom of said vessel.

9. The method of claim 5 including the further step of conditioning said portion of said radioactive waste molten glass following the removal from the vessel by exposing said portion to higher temperatures to further dissolve high melting point constituents of said molten glass bath.