US4476363A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for heating by microwave energy
Assignee: KTH Royal Institute of Technology
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Filing: 1983-09-02
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Granted: 1984-10-09
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Expires: 2003-09-02
Abstract
Abstract A method of heating objects by microwave energy by supplying microwave energy from a generator to a first waveguide. A second waveguide is located, separated from the first waveguide except for at least one parallel and adjacent coupling distance at a common wall between the waveguides. A coupling of microwave energy distributed in the wave propogation direction of the waveguides takes place at the coupling distance so that microwave energy passes from one waveguide to the other one. The second waveguide is dimensioned, so that action of load (objects being heated) conducts microwave energy in the second waveguide with the same wave phase constant as the first waveguide. Objects to be heated are fed only into and out of said second waveguide. A uniform field is fed-in only into the first waveguide. A uniform field distribution and heating profile is obtained and leakage of microwave energy from the open ended second waveguide is avoided.
Inventors
- 👤 Benny Berggren
- 👤 Yngve Hassler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:15
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/72; H05B6/78
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
186 words
A device for heating objects by means of microwave energy, comprising a first feed waveguide with a generator for the supply of microwave energy to said first waveguide, comprising an additional second load waveguide, located adjacent the first waveguide so that the two waveguides at least along a certain distance are parallel and have a partition wall in common, in which partition wall an elongated coupling aperture means is located, said elongated coupling aperture means having a length, by means of which length a coupling of microwave energy distributed in the wave propagation direction of the waveguides takes place from one of said waveguides to the other one and that the load waveguide is dimensioned so that it, when under a no load condition, has a wave phase constant sufficiently different from that of the feed waveguide so that essentially no energy is coupled from the feed waveguide to the load waveguide and also, by action of intended load in the form of objects to be heated in the load waveguide, to conduct microwave energy with the same wave phase constant as the first feed waveguide.
Claim 2
Independent Claim
186 words
A device for heating objects by means of microwave energy, comprising a first feed waveguide with a generator for the supply of microwave energy to said first waveguide, comprising an additional second load waveguide, located adjacent the first waveguide so that the two waveguides at least along a certain distance are parallel and have a partition wall in common, in which partition wall an elongated coupling aperture means is located, said elongated coupling aperture means having a length, by means of which length a coupling of microwave energy distributed in the wave propagation direction of the waveguides takes place from one of said waveguides to the other one and that the load waveguide is dimensioned so that it, when under a no load condition, has a wave phase constant sufficiently different from that of the feed waveguide so that essentially no energy is coupled from the feed waveguide to the load waveguide and also, by action of intended load in the form of objects to be heated in the load waveguide, to conduct microwave energy with the same wave phase constant as the first feed waveguide.
Claim 3
Dependent Claim
48 words
A device as defined in claim 1, characterized by means included in said first waveguide enabling the cross-sectional dimensions of the first waveguide to be continuously changed along at least a section of its length, whereby the wave propagation for energy transported in the first waveguide is changed.
Claim 4
Dependent Claim
40 words
A device as defined in claim 1, characterized in that a dielectric material is inserted in the first waveguide at least along a section of its length, whereby the wave propagation velocity for energy transported in the waveguide is changed.
Claim 5
Dependent Claim
60 words
A device as defined in claim 1, characterized in that said partition wall comprises several lengths of elongated coupling aperture means for coupling-over microwave energy from the first waveguide to the second waveguide and thereafter back to the first waveguide at least once, the number of said lengths of coupling aperture means being equal to the number of said transfers.
Claim 6
Dependent Claim
48 words
A device as defined in claim 4, characterized by means included in said first waveguide enabling the cross-sectional dimensions of the first waveguide to be continuously changed along at least a section of its length, whereby the wave propagation for energy transported in the first waveguide is changed.
Claim 7
Dependent Claim
40 words
A device as defined in claim 4, characterized in that a dielectric material is inserted in the first waveguide at least along a section of its length, whereby the wave propagation velocity for energy transported in the waveguide is changed.
Claim 8
Dependent Claim
66 words
A device as defined in claim 1, wherein there are a plurality of lengths of the elongate coupling aperture means located in the partition wall the total length of the coupling means enabling transferring microwave energy fed into the first waveguide to the second waveguide and back to the first waveguide, and that the first waveguide terminates in a reflection-free load for example a water load.
Claim 9
Dependent Claim
28 words
A device as defined in claim 1, characterized in that the first waveguide is connected by plural lengths; independent elongate coupling means to at least two second waveguides.
Claim 10
Dependent Claim
31 words
A device as defined in claim 1, characterized in that at least two of said first waveguides are connected by plural lengths of independent elongate coupling means to one second waveguide.
Claim 11
Dependent Claim
15 words
A device in claim 1, characterized in that the first waveguide is a ridge waveguide.
Claim 12
Independent Claim
221 words
A method of heating objects by means of microwave energy, utilizing at least one feed waveguide comprising a generator and a first waveguide, and a load waveguide comprising a second waveguide, with load inlet and load outlet, located separate from the first wave guide except for at least one adjacent and parallel elongated coupling aperture means between the waveguides, which coupling aperture means consists of a length, during, and by means of which a coupling of microwave energy distributed in the wave propagation direction of the waveguides is caused to take place so that microwave energy passes from the first waveguide to the second waveguide, except when there is a no load condition existing in the second waveguide; the second waveguide being dimensioned so as, by action of load in said second waveguide in the form of the objects to be heated, to conduct microwave energy with the same wave phase constant as said first waveguide and when there is no load in said second waveguide that essentially no energy will be coupled from the first waveguide to the second waveguide, the steps of feeding objects, to be heated, into and out of only the second waveguide, feeding microwave energy only into the first waveguide and propagating said microwave energy into the second waveguide at said elongated coupling aperture means location.
Claim 13
Independent Claim
221 words
A method of heating objects by means of microwave energy, utilizing at least one feed waveguide comprising a generator and a first waveguide, and a load waveguide comprising a second waveguide, with load inlet and load outlet, located separate from the first wave guide except for at least one adjacent and parallel elongated coupling aperture means between the waveguides, which coupling aperture means consists of a length, during, and by means of which a coupling of microwave energy distributed in the wave propagation direction of the waveguides is caused to take place so that microwave energy passes from the first waveguide to the second waveguide, except when there is a no load condition existing in the second waveguide; the second waveguide being dimensioned so as, by action of load in said second waveguide in the form of the objects to be heated, to conduct microwave energy with the same wave phase constant as said first waveguide and when there is no load in said second waveguide that essentially no energy will be coupled from the first waveguide to the second waveguide, the steps of feeding objects, to be heated, into and out of only the second waveguide, feeding microwave energy only into the first waveguide and propagating said microwave energy into the second waveguide at said elongated coupling aperture means location.
Claim 14
Dependent Claim
35 words
A method as defined in claim 11, characterized in that the wave phase constant in the first waveguide is caused to continuously be changed along its length, by changes in the dimensions of the waveguide.
Claim 15
Dependent Claim
39 words
A method as defined in claim 11, characterized in that the wave propagation velocity in the first waveguide is caused to be changed along the length thereof by inserting a dielectric material, preferably a ceramic material, in the waveguide.
Claim 16
Dependent Claim
58 words
A method as defined in claim 11, characterized in that microwave energy is caused to pass from the first waveguide to the second waveguide and back again to the first waveguide at least once by utilizing the number of coupling distances between the waveguides which is equal to the number of intended passages of energy between the waveguides.
Claim 17
Dependent Claim
35 words
A method as defined in claim 14, characterized in that the wave phase constant in the first waveguide is caused to continuously be changed along its length, by changes in the dimensions of the waveguide.
Claim 18
Dependent Claim
39 words
A method as defined in claim 14, characterized in that the wave propagation velocity in the first waveguide is caused to be changed along the length thereof by inserting a dielectric material, preferably a ceramic material, in the waveguide.
Claim 19
Dependent Claim
56 words
A method as defined in claim 11, characterized in that at least ahead of the terminating end of the waveguides all remaining microwave energy is coupled over to the first waveguide whereafter this energy is caused to be converted to heat in a load, for example water load, located at the end of the first waveguide.
Claim 20
Dependent Claim
44 words
A method as defined in claim 11, characterized in two microwave generators are caused to introduce energy each in an associated waveguide, and causing the microwave energy in all such waveguides to be coupled over to a waveguide provided for the heating of objects.
Claim 21
Dependent Claim
44 words
A method as defined in claim 11, characterized in that a microwave generator is caused to introduce energy into a waveguide, and causing the microwave energy in this waveguide to be coupled over to at least two waveguides provided for the heating of objects.
References Cited (Backward Citations)
US2602859A
Cited
US2948864A
Cited
US3098983A
Cited
US3465114A
Cited
US3851132A
Cited
US3999026A
Cited
US4128751A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |