Patent US3557334A successfully refreshed from Google Patents.
US3557334A
Expired / Lapsed
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Method and apparatus for regulating heating in a microwave resonant cavity
Assignee: EIDP Inc
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Filing: 1969-02-28
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Granted: 1971-01-19
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Expires: 1989-02-28
Abstract
Abstract The method of operation of a microwave resonant cavity system in a preselected undercoupled or overcoupled mode and with preselected frequency offset provides stable heating of dielectric material advancing through the cavity for the purposes of moisture or solvent removal or heat treating. The system includes a three-port circulator coupled between a microwave power source, a resonant cavity and a water load. Means are provided between the circulator and cavity to establish the preselected coupling mode and between the circulator and water load to feed a portion of reflected power from the cavity due to detuning and decoupling to the power source to regulate the shift in frequency of the power source (frequency offset) according to variations in resonant frequency of the load cavity.
Inventors
- 👤 Richard William Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:03
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/78; H05B6/782; H05B6/66; H05B6/666
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
104 words
A method comprising the steps of: a. advancing a dielectric mass axially through a microwave resonant cavity said mass presenting a changing load to said cavity; b. transmitting microwave frequency energy to said cavity from a magnetron source to heat said mass, said cavity being purposefully decoupled and detuned in a preselected direction from a critically coupled and matched frequency relationship with said source for operation at the decoupled and detuned condition selected, a portion of said energy being reflected away from said cavity; and c. absorbing a part of said portion, the remainder being reflected back to said source to regulate its frequency.
Claim 2
Independent Claim
104 words
A method comprising the steps of: a. advancing a dielectric mass axially through a microwave resonant cavity said mass presenting a changing load to said cavity; b. transmitting microwave frequency energy to said cavity from a magnetron source to heat said mass, said cavity being purposefully decoupled and detuned in a preselected direction from a critically coupled and matched frequency relationship with said source for operation at the decoupled and detuned condition selected, a portion of said energy being reflected away from said cavity; and c. absorbing a part of said portion, the remainder being reflected back to said source to regulate its frequency.
Claim 3
Independent Claim
95 words
A method of drying a wet tow having a changing moisture content comprising: a. passing the tow axially through a microwave resonant cavity; b. transmitting microwave frequency energy to said cavity from a magnetron source, said cavity being in an overcoupled relationship with said source and being tuned to a frequency above a matched frequency relationship with said source for operation at said relationships, a portion of said energy being reflected away from said cavity; and c. absorbing a part of said portion, the remainder being reflected back to said source to regulate its frequency.
Claim 4
Independent Claim
95 words
A method of drying a wet tow having a changing moisture content comprising: a. passing the tow axially through a microwave resonant cavity; b. transmitting microwave frequency energy to said cavity from a magnetron source, said cavity being in an overcoupled relationship with said source and being tuned to a frequency above a matched frequency relationship with said source for operation at said relationships, a portion of said energy being reflected away from said cavity; and c. absorbing a part of said portion, the remainder being reflected back to said source to regulate its frequency.
Claim 5
Dependent Claim
14 words
The method as defined in claim 2, said tow comprising multifilament yarns from poly(tetrafluoroethylene).
Claim 6
Dependent Claim
23 words
The method as defined in claim 3, about 11 percent of said portion being reflected back to said source to regulate its frequency.
Claim 7
Dependent Claim
94 words
In a microwave dielectric heating appAratus that includes a cylindrical resonant cavity heater, a microwave frequency energy source for supplying energy to the cavity, a water load and a circulator, said circulator being coupled to said source, said heater and said water load by respective first, second, and third waveguide sections, there being a first iris positioned in said second waveguide section, the improvement comprising: means coupled with said heater for varying the transverse cross section thereof to provide tuning capability for said heater; and a second iris positioned in said third waveguide section.
Claim 8
Dependent Claim
94 words
In a microwave dielectric heating appAratus that includes a cylindrical resonant cavity heater, a microwave frequency energy source for supplying energy to the cavity, a water load and a circulator, said circulator being coupled to said source, said heater and said water load by respective first, second, and third waveguide sections, there being a first iris positioned in said second waveguide section, the improvement comprising: means coupled with said heater for varying the transverse cross section thereof to provide tuning capability for said heater; and a second iris positioned in said third waveguide section.
Claim 9
Dependent Claim
12 words
The apparatus as defined in claim 5, said source being a magnetron.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-18 | 1974-07-20 | 1975-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-18 | 1978-07-20 | 1979-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-18 | 1982-07-20 | 1983-01-19 | $7700.00 | Window Closed / Lapsed |