US4684776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for uniform microwave bulk heating of thick viscous materials in a cavity
Assignee: Shell USA Inc
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Filing: 1986-05-01
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Granted: 1987-08-04
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Expires: 2006-05-01
Abstract
Abstract A method for uniform bulk heating of thick viscous materials in a cavity not specifically designed for microwave heating. Microwaves are passed through a first waveguide to a polarization rotator. The direction of polarization of the incoming waves is rotated slowly and continuously and subsequently the rotated waves are passed through a second waveguide to the cavity to be heated.
Inventors
- 👤 Nigel A. Heard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:46
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/08; B01J19/12; B01J19/122; B01J19/126; H; H05; H05B; H05B6/00; H05B6/64; H05B6/80
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
79 words
A method for uniform microwave bulk heating of thick viscous materials in a cavity not specifically designed for microwave heating comprising the steps of generating microwaves; passing the generated microwaves through a first waveguide to a polarization rotator; slowly and continuously rotating the direction of polarization of the incoming waves wherein the rotation takes place external to the cavity; and subsequently passing the waves to a second waveguide for feeding the rotated waves into the cavity to be heated.
Claim 2
Independent Claim
79 words
A method for uniform microwave bulk heating of thick viscous materials in a cavity not specifically designed for microwave heating comprising the steps of generating microwaves; passing the generated microwaves through a first waveguide to a polarization rotator; slowly and continuously rotating the direction of polarization of the incoming waves wherein the rotation takes place external to the cavity; and subsequently passing the waves to a second waveguide for feeding the rotated waves into the cavity to be heated.
Claim 3
Dependent Claim
15 words
The method of claim 1 wherein the rotation of the polarization direction takes place mechanically.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the rotation takes place at about 1 to about 50 r.p.m.
Claim 5
Dependent Claim
14 words
The method of claim 2 wherein the rotation takes place at about 15 r.p.m.
Claim 6
Dependent Claim
22 words
The method of claim 1 wherein the thick viscous materials are bitumen and the frequency of the microwaves is about 896 MHz.
Claim 7
Dependent Claim
32 words
The method of claim 1 wherein the thick viscous materials are selected from the group consisting lube oil additives and base oils, and the frequency of the microwaves is about 2.45 GHz.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-08-03 | 1991-02-02 | 1991-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-08-03 | 1995-02-02 | 1995-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-08-03 | 1999-02-02 | 1999-08-04 | $7700.00 | Window Closed / Lapsed |