Electric Induction Heating and Stirring of an Electrically Conductive Material in a Containment Vessel

• US 20110011750A1
• Filed: 06/20/2010
• Published: 01/20/2011
• Est. Priority Date: 06/21/2009
• Status: Active Grant

• Current Assignee: Inductotherm Corp
• Original Assignee: Inductotherm Corp
• Inventors: RAFFNER, Bernard M., LOVENS, Jean, FONTAINE, Michel
• Granted Patent: US 8,735,783 B2
• Time in Patent Office: Days
• US Class Current: 205/771
• CPC Class Codes: F27D 11/06 Induction heating, i.e. in which the material being heated, or its container or elements embodied therein, form the secondary of a transformer
• CPC Class Codes: F27D 2099/0015 Induction heating
• CPC Class Codes: F27D 27/00 Stirring devices for molten material F27D3/14 takes precedence
• CPC Class Codes: H05B 2213/02 Stirring of melted material in melting furnaces
• CPC Class Codes: H05B 6/24 Crucible furnaces H05B6/30 takes precedence
• CPC Class Codes: H05B 6/34 Arrangements for circulation of melts
• CPC Class Codes: H05B 6/36 Coil arrangements
• CPC Class Codes: H05B 6/367 for melting furnaces
• CPC Class Codes: H05B 6/42 Cooling of coils
• CPC Class Codes: H05B 6/44 having more than one coil or coil segment
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

Apparatus and method are provided for electric induction heating and/or stirring of a molten electrically conductive composition in a containment vessel with the apparatus being removably insertable in the molten composition. An induction coil embedded in refractory or a coating is submerged in the composition and used to heat and/or stir the molten composition either externally or internally to the refractory or coating.

Claims

1. A method of channeless electric induction heating or stirring of an electrically conductive composition in a containment vessel, the method comprising the steps of:

submerging at least one electric induction apparatus physically distinct from the containment vessel; and

supplying an alternating current to the at least one submerged electric induction apparatus to generate a transverse or longitudinal magnetic flux interacting with the electrically conductive composition to electromagnetically heat the electrically conductive composition.

2. The method of claim 1 further comprising the step of inserting a strip material immersion apparatus in the containment vessel for passing a strip material through the electrically conductive material to coat the strip material.

3. The method of claim 1 further comprising the step of providing electrolysis apparatus in the containment vessel for the extraction of a metal from the electrically conducive composition by an electrolysis process.

4. The method of claim 1 further comprising the step of supply alternating or direct current to an electric resistance element integrated with the at least one submerged electric induction apparatus to heat the electrically conductive composition by conduction of heat generated in the electric resistance element.

5. The method of claim 1 wherein the step of supplying the alternating current to the at least one submerged electric induction apparatus further comprises supplying the alternating current as a single or multiphase alternating current to create an electromagnetically induced flow of the electrically conductive composition.

6. The method of claim 5 further comprising the step of moving the at least one submerged electric induction apparatus in one or more directions to redirect the electromagnetically induced flow of the electrically conductive composition in one or more directions.

7. The method of claim 5 further comprising the step of changing the phasing of the single or multiphase current to redirect the electromagnetically induced flow of the electrically conductive composition in one or more directions.

8. The method of claim 1 further comprising the step of circulating a fluid cooling medium through the at least one submerged electric induction apparatus to withdrawn heat from the electrically conductive composition by heat conduction to the fluid cooling medium.

9. An apparatus for heating or stirring an electrically conductive composition in a containment vessel by electric induction, the apparatus comprising:

an inductor assembly comprising;

one or more induction coils;

a refractory or coating surrounding at least the regions of the one or more induction coils below a coil submersion level; and

at least one alternating current power source connected to the one or more induction coils; and

a transport apparatus for engaging the inductor assembly, the transport apparatus comprising at least a means for lowering the inductor assembly into the electrically conductive composition up to the coil submersion level.

10. The apparatus of claim 9 further comprising one or more cooling passages formed in the one or more induction coils or the refractory.

11. The apparatus of claim 9 further comprising an internal flow passage in the refractory adjacent to at least one side of the one or more induction coils, at least one inlet passage in communication with the internal flow passage, and at least one outlet passage in communication with the internal flow passage whereby a magnetic flux established by the flow of an alternating current from the at least one alternating current power source results in the flow of the electrically conductive composition through the internal flow passage when the inductor assembly is submerged in the containment vessel.

12. The apparatus of claim 9 further comprising at least one external flow channel in the refractory adjacent to at least one side of the one or more induction coils whereby a magnetic flux established by the flow of an alternating current from the at least one alternating current power source results in the flow of electrically conductive composition through the at least one external flow channel when the inductor assembly is submerged in the channeless workpiece coating pot.

13. The apparatus of claim 9 further comprising:

an internal flow passage in the refractory adjacent to a first side of the one or more induction coils, at least one inlet passage in communication with the internal flow passage, and at least one outlet passage in communication with the internal flow passage; and

at least one external flow channel in the refractory adjacent to a second side of the one or more induction coils;

whereby a magnetic flux established by the flow of an alternating current from the at least one alternating current power source results in the flow of the electrically conductive composition through the internal flow passage and the flow of electrically conductive composition through the at least one external flow channel when the inductor assembly is submerged in the channeless workpiece coating pot.

14. The apparatus of claim 9 wherein the transport apparatus further comprises a lock and release mechanism for engaging or disengaging the inductor assembly when the inductor assembly is lowered into the electrically conductive composition.

15. The apparatus of claim 9 wherein the transport apparatus further comprises an inductor assembly translation or rotation subassembly for translating or rotating the engaged inductor assembly when the inductor assembly is lowered into the electrically conductive composition.

16. The apparatus of claim 9 wherein at least one of the one or more induction coils is formed from litz wire.

17. The apparatus of claim 9 further comprising at least one passage within the refractory, the at least one passage having an exit opening submerged in the electrically conductive composition and a non-submerged entry opening when the apparatus is lowered into the electrically conductive composition, the non-submerged entry opening connected to a fluid or gas supply for injecting a fluid or gas into the electrically conductive composition through the at least one passage.

18. The apparatus of claim 9 further comprising:

at least one resistive heating element embedded in the refractory; and

at least one source of electric power connected to the at least one resistive heating element.

19. The apparatus of claim 9 further comprising a strip material immersion apparatus disposed in the containment vessel for continuously passing a strip material through the electrically conductive composition to coat the strip material, or an electrolysis apparatus disposed in the containment vessel for the extraction of a metal from the electrically conductive composition by an electrolysis process.

20. An inductor assembly for heating or stirring an electrically conductive composition in a channeless containment vessel by electric induction, the inductor assembly comprising:

at least two electrically interconnected induction coils, the at least two electrically interconnected induction coils spaced apart from each other to form a gap;

a refractory surrounding at least the regions of the at least two electrically interconnected induction coils below a coil submersion level, an internal flow passage formed in the gap, at least one inlet passage in communication with the internal flow passage, and at least one outlet passage in communication with the internal flow passage; and

at least one alternating current power source connected to the at least two electrically interconnected induction coils to electromagnetically force the electrically conductive material by transverse flux through the internal flow passage from the at least one inlet passage to the at least one outlet passage when the refractory surrounded at least two electrically interconnected induction coils are submerged in the electrically conductive material.

21. The inductor assembly of claim 20 further comprising a transport apparatus for engaging the inductor assembly, the transport apparatus comprising at least means for lowering the inductor assembly into the electrically conductive composition up to the coil submersion level.

22. The inductor assembly of claim 20 further comprising one or more cooling passages formed in the at least two electrically interconnected induction coils or the refractory.

23. The inductor assembly of claim 20 further comprising an internal flow passage in the refractory adjacent to at least one side of the at least two electrically interconnected induction coils, at least one inlet passage in communication with the internal flow passage, and at least one outlet passage in communication with the internal flow passage whereby a magnetic flux established by the flow of an alternating current from the at least one alternating current power source results in the flow of the electrically conductive composition through the internal flow passage when the inductor assembly is submerged in the channeless workpiece coating pot.

24. The inductor assembly of claim 20 wherein the transport apparatus further comprises a lock and release mechanism for engaging or disengaging the inductor assembly.

25. The inductor assembly of claim 20 wherein the transport apparatus further comprises an inductor assembly translation or rotation subassembly for translating or rotating the engaged inductor assembly.

26. The inductor assembly of claim 20 wherein at least one of the one or more induction coils is formed from litz wire.

27. The inductor assembly of claim 20 further comprising at least one passage within the refractory having an exit opening submerged in the electrically conductive composition and a non-submerged entry opening when the apparatus is submerged in the electrically conductive composition, the non-submerged entry opening connected to a fluid or gas supply for injecting a fluid or gas into the electrically conductive composition through the at least one passage.

28. The inductor assembly of claim 20 further comprising:

at least one resistive heating element embedded in the refractory; and

at least one source of electric power connected to the at least one resistive heating element.

29. The inductor assembly of claim 20 further comprising a strip material immersion apparatus disposed in the containment vessel for continuously passing a strip material through the electrically conductive composition to coat the strip material, or an electrolysis apparatus disposed in the containment vessel for the extraction of a metal from the electrically conductive composition by an electrolysis process.