Claims
- 1. A method of incinerating and melting waste materials comprising:
- directing waste materials into a regions having a bottom surface and a wall surface extending transversely from the bottom surface;
- rotating said region with the waste materials therewithin at a speed sufficient to cause centrifugal distribution of the waste materials against the bottom and wall surfaces;
- directing a high temperature plasma of the transferred arc type into the region to incinerate and melt the waste materials as the region rotates; and
- directing the products of combustion as an effluent from the region.
- 2. A method as set forth in claim 1, wherein the effluent passes along a path above the region.
- 3. A method as set forth in claim 1, wherein the plasma is in the temperature range of 10,000.degree. to 15,000.degree. Centigrade.
- 4. A method as set forth in claim 1, wherein said waste materials are hazardous waste materials.
- 5. A method as set forth in claim 1, wherein the effluent passes along a path below said region.
- 6. A method as set forth in claim 5, wherein is included the step of blocking said path of the effluent as the region continues to rotate.
- 7. A method as set forth in claim 1, wherein is included the step of changing the direction of the plasma as it is directed into the region and while the region is rotating.
- 8. A method as set forth in claim 1, wherein is included the step of separating the solid products of combustion from the gaseous products of combustion.
- 9. A method as set forth in claim 1, wherein is included the step of varying the speed of rotation of the region.
- 10. A method as set forth in claim 1, wherein is included the step of allowing the waste materials to be in a layer on the wall surface of the region to present a relatively large surface area of the waste materials to the heat of the plasma.
- 11. A method as set forth in claim 10, wherein said allowing step includes varying the speed of rotation of said region.
- 12. A method as set forth in claim 1, wherein the effluent passes along a path through a hole extending downwardly from said region.
- 13. A method as set forth in claim 12, wherein is included the step of applying heat energy to the effluent as it passes into and through the hole.
- 14. A method as set forth in claim 12, wherein said step of applying heat to the effluent includes directing a high temperature plasma of the transferred arc type into the hole.
- 15. A method of incinerating and melting waste materials comprising:
- directing waste materials into a region closed to the atmosphere and having a bottom hole;
- rotating said region with the waste materials therewithin at a speed sufficient to cause centrifugal distribution of the waste materials;
- directing a high temperature plasma into the region to incinerate and melt the waste materials; and
- directing the products of combustion as an effluent from the region through said hole.
- 16. A method as set forth in claim 15, wherein is included the step of applying heat energy to the effluent as it passes into and through the hole.
- 17. A method as set forth in claim 16, wherein said step of applying heat to the effluent includes directing a high temperature plasma of the transferred arc type at least at the entrance of the hole.
- 18. A method as set forth in claim 12, wherein is included the step of adding a gas to the effluent as it passes through the hole to enhance the combustion of the effluent.
- 19. A method as set forth in claim 18, wherein said gas is taken from the group including oxygen and air.
- 20. A method as set forth in claim 12, wherein said step of directing a high temperature plasma includes heating with a plasma of the transferred arc type into the region.
- 21. A method as set forth in claim 12, wherein the speed of rotation of said region is in the range of 5 rpm to 150 rpm.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 65-29796 |
Mar 1989 |
JPX |
|
BACKGROUND OF THE INVENTION
This is a continuation-in-part application of application Ser. No. 173,968, filed Mar. 28, 1988, now abandoned, which was a division of application Ser. No. 046,483, filed May 4, 1987, now U.S. Pat. No. 4,770,109.
This invention relates to improvements in the treating of waste materials, especially of hazardous waste materials containing combustibles and critical, high performance alloys and, more particularly, to apparatus and a method for disposing of hazardous waste materials by incineration, pyrolysis, and melting.
The disposal of waste materials, especially toxic wastes, with plasma torches is well known and has been performed in the past. In such a process, a plasma torch transfers electrical energy through a stream of ionized gases so that the gases become an electrical conductor. With such a torch, very high temperatures in the area of 10,000.degree.-15,000.degree. Centigrade can be attained.
In general, there are two types of plasma torches, one a non-transferred arc torch and the other a transferred arc torch. In the non-transferred arc torch, the electrical potential is entirely contained within the torch, i.e., between two axially spaced rings. In such a torch, hot gases are emitted from one end of the torch.
A transferred arc torch, on the other hand, can be used in which the torch tube or body is one side of an electrical field and the other side of the field is exteriorly of the torch and spaced from the torch. The transferred arc torch is the more efficient one and enables the attainment of higher operating temperatures.
A plasma torch disposal reactor raises the temperature of waste materials, including toxic waste materials, through such high levels that such materials chemically break down (pyrolysis). This breakdown can be enhanced by maintaining an atmosphere of the appropriate gas in the incinerator. As a result, the residues are usually harmless gases and solids which are suitably removed from the incinerator.
While conventional plasma torch incinerators are satisfactory in certain applications, they have their drawbacks inasmuch as the waste materials treated thereby are sometimes not presented efficiently to the plasma torch thereof so as to provide for complete incineration, pyrolysis, or melting of the waste materials. Because of such drawbacks, a need exists for improvements in plasma torch reactors and the present invention satisfies this need.
Patents relating to the field of materials incineration include U.S. Pat. Nos. 3,599,581, 3,779,182, 4,181,504, 4,582,004 and 4,615,285 and British patent 1,170,548.
The present invention provides an improved plasma torch incinerator or reactor in which the incinerator uses a rotating, materials-receiving drum or chamber for receiving the hot plasma of a plasma torch. By appropriately constructing the inner surface profile of the rotatable drum and by varying the speed of rotation of the drum, waste materials directed into the incinerator can be effectively spread out over the inner surface of the drum. This spreading out effect forms a relatively thin layer of waste materials which has a large surface area which can be more quickly heated to the desired high temperatures provided by the plasma torch. Moreover, the spreading out of the waste materials can cause them to be recirculated and mixed by periodically reducing the speed of rotation of the drum to permit materials to flow and thereby be spread out by gravity from the side and bottom walls of the drum.
Another advantage of the present invention is the fact that the plasma of the plasma torch is not directed toward a stationary part of the drum itself. This would tend to overheat the drum and to limit the temperature with which the plasma torch may be operated. Instead, the plasma torch is directed at a rotatable portion of the drum which provides for a better heat distribution and permits portions of the drum to cool during the intervals when they are not in direct contact with the plasma plume of the plasma torch. Thus, it is no longer necessary to feed the materials into the incinerator in liquid form as is true with certain conventional waste incinerators. Thus, with the improvements of the present invention, liquid as well as solid waste materials can be fed directly into the rotating drum so as to greatly simplify the handling of such wastes.
The primary object of the present invention is to provide apparatus and a method for handling waste materials, especially hazardous waste materials containing both combustibles non-combustibles, and metals, wherein the apparatus includes a rotary drum in a closed vessel adapted for receiving the waste materials and the speed of the drum can be controlled to cause a change in the distribution of the waste materials on the inner surface portions of the drum so as to present the waste materials more efficiently to the plasma plume of a plasma torch while assuring that the temperatures of the plasma torch remain sufficiently high to achieve such efficient incineration pyrolysis or melting of the waste materials.
Another object of the present invention is to provide apparatus and method of the type described wherein a transferred arc type of plasma torch can be used to achieve a relatively high operating temperatures yet the materials-receiving drum itself can provide a rotatable portion subjected to the plasma of the plasma torch so that the drum has no stationary part in contact with the plasma and the drum can thereby cool periodically as it rotates.
Other objects of this invention will become apparent as the following specification progresses, reference being had to the accompanying drawings for an illustration of the invention.
US Referenced Citations (12)
Foreign Referenced Citations (1)
| Number |
Date |
Country |
| 1170548 |
Nov 1969 |
GBX |
Divisions (1)
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Number |
Date |
Country |
| Parent |
46483 |
May 1987 |
|
Continuation in Parts (1)
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Number |
Date |
Country |
| Parent |
173968 |
Mar 1988 |
|
Patent Grant
5005494
