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US4746547A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for circulating bed coater

Assignee: General Atomics Corp
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Filing: 1986-12-29
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Granted: 1988-05-24
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Expires: 2006-12-29
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Abstract

Abstract This invention relates to particle coaters and in particular to a method and apparatus for a circulating bed particle coater which is particularly adapted for coating small diameter particles.

Inventors

  • 👤 Lloyd C. Brown
  • 👤 Charles C. Adams
  • 👤 Gottfried E. A. Besenbruch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 09:35
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/442; B; B01; B01J; B01J2/00; B01J2/006; B01J2/16; B05; B05C; B05C9/00; B05C9/02; B22; B22F; B22F1/00; B22F1/16; B22F2998/00; Y; Y10; Y10S; Y10S118/00; Y10S118/05

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 127 words
A method for coating small particles comprising: A. establishing a fluidized bed reservoir of particles to be coated, B. entraining a portion of the fluidized particles in the reservoir in a flowing transport gas stream to provide a mixture of transport gas and entrained particles, said transport gas stream including a decomposible gas fraction, C. transporting the mixture of transport gas and entrained particles from the fluidized bed through a furnace spaced from the reservoir at a flow rate sufficient to prevent agglomeration of the particles, D. heating the mixture of transport gas and entrained particles in the furnace to above the decomposition temperature of the decomposible gas. E. separating the particles from the exhaust transport gas, and F. reintroducing the particles into the fluidized bed reservoir.
Claim 2
Independent Claim 127 words
A method for coating small particles comprising: A. establishing a fluidized bed reservoir of particles to be coated, B. entraining a portion of the fluidized particles in the reservoir in a flowing transport gas stream to provide a mixture of transport gas and entrained particles, said transport gas stream including a decomposible gas fraction, C. transporting the mixture of transport gas and entrained particles from the fluidized bed through a furnace spaced from the reservoir at a flow rate sufficient to prevent agglomeration of the particles, D. heating the mixture of transport gas and entrained particles in the furnace to above the decomposition temperature of the decomposible gas. E. separating the particles from the exhaust transport gas, and F. reintroducing the particles into the fluidized bed reservoir.
Claim 3
Dependent Claim 18 words
The method of claim 1 wherein the particles have a particle size of less than about 100 microns.
Claim 4
Dependent Claim 18 words
The method of claim 1 wherein the particles have a particle size of less than about 40 microns.
Claim 5
Dependent Claim 28 words
The method of claim 3 wherein the mixture of transport gas and entrained particles has a flow rate of between about 15 and about 60 l/min/cm 2 .
Claim 6
Dependent Claim 25 words
The method of claim 3 wherein the mixture of transport gas and entrained particles has a flow rate in excess of 30 l/min/cm 2 .
Claim 7
Dependent Claim 17 words
The method of claim 3 wherein the particles are recirculated until a pinhole free coating is obtained.
Claim 8
Dependent Claim 35 words
The method of claim 4 wherein the decomposable gas is selected from triethyl aluminum and hydrogen, trimethyl aluminum and hydrogen, arsine and Ga 2 H 6 , silane, methyl trichlorosilane, benzene, acetylene, propylene and methane.
Claim 9
Dependent Claim 111 words
Apparatus for coating small particles comprising: A. a fluidized bed reservoir particles to be coated, B. means for introducing and withdrawing from the fluidized bed reservoir a transport gas stream for entraining a portion of the particles in the reservoir. C. heater means for heating the flowing mixture of a transport gas and entrained particles, D. separator means for separating the particles from the exhaust transport gas stream exiting the heater means, E. means for reintroducing the separated particles into the fluidized bed reservoir, F. and means for causing sufficient agitation of the flowing stream of transport gas and entrained particles in the heater means to prevent agglomeration of the particles.
Claim 10
Dependent Claim 111 words
Apparatus for coating small particles comprising: A. a fluidized bed reservoir particles to be coated, B. means for introducing and withdrawing from the fluidized bed reservoir a transport gas stream for entraining a portion of the particles in the reservoir. C. heater means for heating the flowing mixture of a transport gas and entrained particles, D. separator means for separating the particles from the exhaust transport gas stream exiting the heater means, E. means for reintroducing the separated particles into the fluidized bed reservoir, F. and means for causing sufficient agitation of the flowing stream of transport gas and entrained particles in the heater means to prevent agglomeration of the particles.
Claim 11
Dependent Claim 18 words
The apparatus of claim 8 including means to cool the mixture of exhaust transport gas and entrained particles.
Claim 12
Dependent Claim 15 words
The apparatus of claim 8 wherein the heater means is a resistance heated tubular furnace.

References Cited (Backward Citations)

US4542043A Cited
US4594270A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-05-24 1991-11-23 1992-05-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-05-24 1995-11-23 1996-05-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-05-24 1999-11-23 2000-05-24 $7700.00 Window Closed / Lapsed

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