Method and apparatus for waste vitrification

• US 7,120,185 B1
• Filed: 10/31/1991
• Issued: 10/10/2006
• Est. Priority Date: 04/18/1990
• Status: Active Grant

• Current Assignee: Stir-Melter Incorporated
• Original Assignee: Stir-Melter Incorporated
• Inventors: Richards, Ray S.
• Primary Examiner(s): MAI, NGOCLAN THI
• Application Number:
  US07/785,776
• Time in Patent Office: 5,458 Days
• Field of Search: 423/DIG.20, 422/159, 422/903, 252/629, 373/27, 373/29, 373/39, 373/41, 373/36, 588/11
• US Class Current: 373/41
• 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 5/033 by using resistance heaters above or in the glass bath, i.e. by indirect resistance heating
• CPC Class Codes: C03B 5/1875 of the screw or pump-action type
• CPC Class Codes: C03B 5/26 Outlets , e.g. drains, siphons; Overflows , e.g. for supplying the float tank, tweels
• CPC Class Codes: G21F 9/305 Glass or glass like matrix C03B5/005 takes precedence; compositional aspects C03C
• CPC Class Codes: Y02P 40/50 Glass production, e.g. reusing waste heat during processing or shaping
• CPC Class Codes: Y02P 40/57 Improving the yield, e-g- reduction of reject rates
• CPC Class Codes: Y10S 422/903 Radioactive material apparatus

Abstract

A waste vitrification apparatus (10) having rotatable mixer impeller (16) functioning as a shaft electrode (60) and metallic vessel (14) functioning as a vessel electrode (62). A stream (12) of waste material and vitrifiable material are mixed and melted in the vessel (14) for vitrification. The waste vitrification method converts a feed stream (12) by mixing the feed stream into a glass melt (13) and melting glass batch of the feed stream (12) to form a foamy mass. The stream is dispersed by the impeller (16) to form a foam which is then densified in a settling zone (22), recovered through a spout (24) and solidified in storage containers. Means are provided to adjust the location of the mixing impeller (16) in the vessel (14) to change the depth of the settling zone (22). The impeller (16) is mounted on a drive shaft (18) having a recirculating coolant flow.

Claims

1. A waste vitrification apparatus for vitrifying a feed stream having vitrifiable materials and waste materials comprising:

a vessel at least partially formed of an electrically conductive material containing a glass melt and defining a mixing zone;

a mixing impeller at least partially formed of an electrically conductive material;

a drive shaft extending into said mixing zone of said vessel, said impeller being connected to said drive shaft;

means for rotating the drive shaft and said impeller in said mixing zone to disperse the constituents of the feed stream into the glass melt;

means for creating electrical current flow between the vessel and said impeller sufficient to heat the feed stream until the vitrifiable material melts to a liquid state forming a solidifiable output including the waste material and the melted vitrifiable material;

a settling zone in fluid flow communication with the mixing zone; and

an outlet opening through which said solidifiable output is ported for cooling and solidification.

2. The apparatus of claim 1 wherein said settling zone is provided in the same vessel containing said mixing zone.

3. The apparatus of claim 1 wherein said settling zone is provided in the same vessel as the mixing zone and is disposed below the mixing zone.

4. The apparatus of claim 1 wherein said settling zone is provided in a separate vessel from said vessel containing said mixing zone.