Claims
- 1. An instrument for microwave-assisted chemical processes that avoids tuning discrepancies that otherwise result based upon the size and composition of the materials being heated, said instrument comprising:a source of microwave radiation; a waveguide in communication with said source, with at least a portion of said waveguide forming an annulus with a rectangular cross section; a right cylindrical static cavity including a circular floor and a circular attenuator and immediately surrounded by said annular portions of said waveguide; and at least 3 slotted openings in the circumference of said annular waveguide that provide microwave communication between said waveguide and said static cavity and optimized coupling between microwaves from said source and materials being heated.
- 2. An instrument according to claim 1 wherein said microwave source is selected from the group consisting of magnetrons and klystrons.
- 3. An instrument according to claim 1 wherein said microwave source is a solid state source.
- 4. An instrument according to claim 1 wherein said waveguide includes seven slots equally spaced from one another by at least 40°.
- 5. An instrument according to claim 1 wherein said cylindrical cavity completes a fall 360°.
- 6. An instrument according to claim 1 wherein said annular waveguide completes more than 180°.
- 7. An instrument according to claim 1 wherein said annular waveguide completes between 270 and 360°.
- 8. An instrument according to claim 1 wherein said slotted openings are oriented parallel to the axis of said cylindrical cavity.
- 9. An instrument according to claim 1 wherein said waveguide is formed of metal.
- 10. An instrument according to claim 1 and further comprising means for measuring the temperature of items in said cavity.
- 11. An instrument according to claim 10 wherein said temperature measurement means comprises an infrared photo detector positioned to receive infrared radiation from items in said cavity.
- 12. An instrument according to claim 10 and further comprising means for moderating the application of microwaves in response to the measured temperature.
- 13. An instrument according to claim 12 wherein said moderating means comprises a processor in communication with said source and said temperature measurement means for moderating the output of said source in response to the measured temperature.
- 14. An instrument according to claim 1 and further comprising means for measuring the pressure in said cavity.
- 15. An instrument according to claim 14 comprising a pressure transducer.
- 16. An instrument according to claim 4, and further comprising means for moderating the application of microwaves in response to the measured pressure.
- 17. An instrument according to claim 16 wherein said moderating means comprises a processor in communication with said source and said pressure measurement means for moderating the output of said source in response to the measured pressure.
- 18. An instrument according to claim 1 and further comprising means for cooling said cavity in response to elevated temperatures resulting from chemical reactions being carried out in said cavity.
- 19. An instrument according to claim 1 and further comprising a cylindrical dielectric insert inside said cavity and adjacent the circumference of said cavity.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of Ser. No. 09/773,846 filed Jan. 31, 2001. This application is related to copending applications Ser. Nos. 10/063,628 filed May 3, 2002 and 10/063,914 filed May 23, 2002.
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Raner, Kevin D. et al.; A New Microwave Reactor for Batchwise Organic Synthesis; The Journal of Organic Chemistry, American Chemical Society, Easton, U.S.; vol. 60, No. 8, pp. 2456-2460. |
Continuations (1)
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Number |
Date |
Country |
Parent |
09/773846 |
Jan 2001 |
US |
Child |
10/248052 |
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US |