US5405658A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon coating process
Assignee: Albemarle Corp
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Filing: 1992-10-20
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Granted: 1995-04-11
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Expires: 2012-10-20
Abstract
Abstract This invention relates to an improved process for the thermal dehydrogenation of polysilicon granules in a fluidized bed reactor, the improvement which comprises introducing a varying electromagnetic field into the reactor whereby reactor walls are coated with silicon during the dehydrogenation.
Inventors
- 👤 Jameel Ibrahim
- 👤 Robert E. Farritor
- 👤 David W. Clary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:04
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/02; C01B33/021; C01B33/027; B; B01; B01J; B01J19/00; B01J19/02; B01J19/08; B01J19/12; B01J8/00; B01J8/18; B01J8/24; B01J2219/00; B01J2219/02; B01J2219/0204; B01J2219/08; B01J2219/0873; B01J2219/0879
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
In a process for the thermal dehydrogenation of polysilicon granules in a fluidized bed reactor, the improvement which comprises subjecting the polysilicon granules to a varying electromagnetic field within the reactor while the particles are at a temperature of from about 900° C. to about 1300° C., the particles being subjected to the varying electromagnetic field for a time sufficient to obtain a silicon coat on reactor walls.
Claim 2
Dependent Claim
68 words
In a process for the thermal dehydrogenation of polysilicon granules in a fluidized bed reactor, the improvement which comprises subjecting the polysilicon granules to a varying electromagnetic field within the reactor while the particles are at a temperature of from about 900° C. to about 1300° C., the particles being subjected to the varying electromagnetic field for a time sufficient to obtain a silicon coat on reactor walls.
Claim 3
Dependent Claim
33 words
The process of claim 1 wherein the electromagnetic field cyclically varies between a minimum and maximum value at a rate within the range of from about 800 to about 4000 cycles per second.
Claim 4
Dependent Claim
32 words
The process of claim 1 wherein the varying electromagnetic field is generated by an inductor which comprises an electrically conductive coil located around the reactor, which coil carries an electrical alternating current.
Claim 5
Dependent Claim
25 words
The process of claim 3 wherein the alternating current has a frequency within the range of from about 800 to about 4000 cycles per second.
Claim 6
Dependent Claim
63 words
A process for thermally dehydrogenating polysilicon granules in a fluidized bed reactor and simultaneously forming a silicon coat on interior reactor walls, which process comprises (a) fluidizing within the reactor polysilicon granules containing diffusible hydrogen; (b) maintaining thermal dehydrogenation conditions within the reactor; and (c) simultaneously providing a sufficient and varying electromagnetic flux density within the reactor whereby the silicon coating is obtained.
Claim 7
Dependent Claim
63 words
A process for thermally dehydrogenating polysilicon granules in a fluidized bed reactor and simultaneously forming a silicon coat on interior reactor walls, which process comprises (a) fluidizing within the reactor polysilicon granules containing diffusible hydrogen; (b) maintaining thermal dehydrogenation conditions within the reactor; and (c) simultaneously providing a sufficient and varying electromagnetic flux density within the reactor whereby the silicon coating is obtained.
Claim 8
Dependent Claim
45 words
The process of claim 5 wherein the reactor walls are heated by radiation heat from a susceptor which is about the exterior of the reactor walls and which is inductively heated by an inductor, which inductor also provides for the electromagnetic field within the reactor.
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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) | 1998-04-10 | 1998-10-10 | 1999-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-10 | 2002-10-10 | 2003-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-10 | 2006-10-10 | 2007-04-11 | $7700.00 | Window Closed / Lapsed |