Patent US5405658A successfully refreshed from Google Patents.
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 13:55
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.
References Cited (Backward Citations)
US4292344A
Cited
US4668493A
Cited
US4751067A
Cited
US4684513A
Cited
US4981102A
Cited
US4784840A
Cited
US4883687A
Cited
US4748052A
Cited
US4868013A
Cited
US5041308A
Cited
JPH03150288A
Cited
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 |