Patent US3923467A successfully refreshed from Google Patents.
US3923467A
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Production of ultra fine refractory particles from refractory material using plasma flows and a fluidized bed
Assignee: Bpifrance Financement SA
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Filing: 1971-12-28
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Granted: 1975-12-02
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Expires: 1991-12-28
Abstract
Abstract The device is especially adapted to the partial vaporisation of powdered refractory materials and comprises a vertical enclosure with an exhaust opening to the outside in its upper portion. In its lower portion orientable nozzles provide convergent elementary flows of plasma traversable by an electric current to generate the principal flow of plasma with a flared shape. Above the convergent point of the elementary flows, the cross-section of the principal flow reaches a value equal or close to the internal cross-section of the enclosure. A funnel introduces the powders by gravity into the principal flow. Injectors of cold gas into the enclosure above the principal flow and cooling means for the walls can be included.
Inventors
- 👤 Claude Bonet
- 👤 Marc Foex
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:24
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/622; C04B35/626; B; B01; B01J; B01J2/00; B01J2/16; B01J8/00; B01J8/18; B01J8/24; B01J8/42; C03; C03B; C03B19/00; C03B19/10; C03B19/1005; C03B19/102; C03B19/1025; C03B19/103; H; H05; H05H; H05H1/00; H05H1/24; H05H1/26; H05H1/32; B01J2219/00; B01J2219/08; B01J2219/0894
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
247 words
A METHOD FOR THE PRODUCTION OF ULTRA FINE REFRACTORY PARTICLES FROM A REFRACTORY MATERIAL IN THE FORM OF RELATIVELY COARSE PARTICLES WHICH COMPRISES GENERATING A PLURALITY OF UPWARDLY DIRECTED PLASMA FLOWS IN THE LOWER PORTION OF A VERTICAL ENCLOSURE, THE DIRECTION OF SAID PLASMA FLOWS BEING ORIENTED TO CONVERGE AT A POINT SUBSTANITALLY AT THE VERTICAL AXIS OF SAID ENCLOSURE TO FORM A PRINCIPAL FLOW OF HOT GASES MOVING UPWARDS, SAID GASES HAVING A TEMPERATURE ABOVE THE VAPORIZATION TEMPERATURE OF SAID RERACTORY PARTICLES, CAUSING AN ELECDTRIC CURRENT TO FLOW THROUGH SAID CONVERGENT FLOWS IN AN ARC ACROSS THE BOTTOM OF THE ENCLOSURE AT AN ENERGY LEVEL OF AT LEAST ABOUT 38.5 KW, INTRODUCING SAID REFRACTORY COARSE PARTICLES BY GRAVITY INTO SAID PRINCIPAL FLOW OF HOT GASES ABOVE SAID POINT OF CONVERGENCE, CONTROLLING THE ORIENTATIONS AND THE FLOW RATES OF SAID PLASMA FLOWS AND THE ELECTRICAL ENERGY DISSIPATED THEREIN TO IMPART TO SAID PRINCIPAL FLOW A FLARED SHAPE TERMINATING IN A CROSS-SECTION SUBSTANTIALLY EQUAL TO THE INTERNAL DIAMETER OF SAID ENCLOSURE, SAID PLASMA FLOWS HAVING A SUFFICIENTLY REDUCED SPEED SO AS TO FORM A FLUIDIZED BED OF SAID REFRACTORY PARTICLES THEREIN, AND TO ENSURE THAT THE HOT GASES HAVE A TEMPERATURE HIGHER THAN THE VAPORIZATION TEMPERATURE OF SAID REFRACTORY MATERIAL, CONTROLLING THE RATE OF INTRODUCTION VAPORIZATION OF AT LEAST PART OF SAID COARSE REFRACTORY PARTICLES IN THE FLUIDIZED BED, AND REMOVING HOT GASES CONTAINING VAPORIZED REFRACTORY MATERIALS AND FINE REFRACTORY PARTICLES ENTRAINED THEREIN FROM ABOVE SAID FLUIDIZED BED.
Claim 2
Independent Claim
247 words
A METHOD FOR THE PRODUCTION OF ULTRA FINE REFRACTORY PARTICLES FROM A REFRACTORY MATERIAL IN THE FORM OF RELATIVELY COARSE PARTICLES WHICH COMPRISES GENERATING A PLURALITY OF UPWARDLY DIRECTED PLASMA FLOWS IN THE LOWER PORTION OF A VERTICAL ENCLOSURE, THE DIRECTION OF SAID PLASMA FLOWS BEING ORIENTED TO CONVERGE AT A POINT SUBSTANITALLY AT THE VERTICAL AXIS OF SAID ENCLOSURE TO FORM A PRINCIPAL FLOW OF HOT GASES MOVING UPWARDS, SAID GASES HAVING A TEMPERATURE ABOVE THE VAPORIZATION TEMPERATURE OF SAID RERACTORY PARTICLES, CAUSING AN ELECDTRIC CURRENT TO FLOW THROUGH SAID CONVERGENT FLOWS IN AN ARC ACROSS THE BOTTOM OF THE ENCLOSURE AT AN ENERGY LEVEL OF AT LEAST ABOUT 38.5 KW, INTRODUCING SAID REFRACTORY COARSE PARTICLES BY GRAVITY INTO SAID PRINCIPAL FLOW OF HOT GASES ABOVE SAID POINT OF CONVERGENCE, CONTROLLING THE ORIENTATIONS AND THE FLOW RATES OF SAID PLASMA FLOWS AND THE ELECTRICAL ENERGY DISSIPATED THEREIN TO IMPART TO SAID PRINCIPAL FLOW A FLARED SHAPE TERMINATING IN A CROSS-SECTION SUBSTANTIALLY EQUAL TO THE INTERNAL DIAMETER OF SAID ENCLOSURE, SAID PLASMA FLOWS HAVING A SUFFICIENTLY REDUCED SPEED SO AS TO FORM A FLUIDIZED BED OF SAID REFRACTORY PARTICLES THEREIN, AND TO ENSURE THAT THE HOT GASES HAVE A TEMPERATURE HIGHER THAN THE VAPORIZATION TEMPERATURE OF SAID REFRACTORY MATERIAL, CONTROLLING THE RATE OF INTRODUCTION VAPORIZATION OF AT LEAST PART OF SAID COARSE REFRACTORY PARTICLES IN THE FLUIDIZED BED, AND REMOVING HOT GASES CONTAINING VAPORIZED REFRACTORY MATERIALS AND FINE REFRACTORY PARTICLES ENTRAINED THEREIN FROM ABOVE SAID FLUIDIZED BED.
Claim 3
Dependent Claim
26 words
Method according to claim 1, wherein the powder is introduced into the principal flow by means of an auxiliary gaseous current converging with the principal flow.
Claim 4
Dependent Claim
17 words
Method according to claim 2, wherein the auxiliary gaseous current is itself constituted by a plasma flow.
Claim 5
Dependent Claim
37 words
Method according to claim 1, whereiN an auxiliary gaseous current is injected into the enclosure, at its bottom, at a flow rate adapted to entrain into the principal flow particles present in the bottom of the enclosure.
Claim 6
Dependent Claim
61 words
Method according to claim 1, wherein there is injected into the enclosure, above the principal flow, gases for the tempering and condensation of the vapors formed in the fluidised bed formed in the principal flow, the gases from the latter entraining the tempering gases and condensed vapors towards an outside of the enclosure, through the opening formed in its upper portion.
Claim 7
Dependent Claim
19 words
Method according to any one of claim 1, wherein at least partial vaporisation of the refractory powders is effected.
Claim 8
Dependent Claim
16 words
Method according to claim 1, wherein a vertical enclosure is used, open in its upper portion.
Claim 9
Dependent Claim
13 words
Method according to claim 7, wherein the walls of the enclosure are cooled.
Claim 10
Independent Claim
257 words
A method for the production of ultra fine refractory particles from a refractory material in the form of relatively coarse particles which comprises generating a plurality of upwardly directed plasma flows in the lower portion of a vertical enclosure, the direction of said plasma flows being oriented to converge at a point substantially at the vertical axis of said enclosure to form a principal flow of hot gases moving upwards, said gases having a temperature above the vaporization temperature of said refractory particles, causing an electric current to flow through said convergent flows in an arc across the bottom of the enclosure at an energy level of at least about 38.5 kw, introducing said refractory coarse particles into said principal flow of hot gases above said point of convergence, controlling the orientations and the flow rates of said plasma flows and the electrical energy dissipated therein to impart to said principal flow a flared shape terminating in a cross-section substantially equal to the internal diameter of said enclosure, said plasma flows having a sufficiently reduced speed so as to form a fluidized bed of said refractory particles therein, and to ensure that the hot gases have a temperature higher than the vaporization temperature of said refractory material, controlling the rate of introduction of said refractory material in said plasma flow to allow for the vaporization of at least part of said coarse refractory particles in the fluidized bed, and removing hot gases containing vaporized refractory materials and fine refractory particles entrained therein from above said fluidized bed.
Claim 11
Independent Claim
257 words
A method for the production of ultra fine refractory particles from a refractory material in the form of relatively coarse particles which comprises generating a plurality of upwardly directed plasma flows in the lower portion of a vertical enclosure, the direction of said plasma flows being oriented to converge at a point substantially at the vertical axis of said enclosure to form a principal flow of hot gases moving upwards, said gases having a temperature above the vaporization temperature of said refractory particles, causing an electric current to flow through said convergent flows in an arc across the bottom of the enclosure at an energy level of at least about 38.5 kw, introducing said refractory coarse particles into said principal flow of hot gases above said point of convergence, controlling the orientations and the flow rates of said plasma flows and the electrical energy dissipated therein to impart to said principal flow a flared shape terminating in a cross-section substantially equal to the internal diameter of said enclosure, said plasma flows having a sufficiently reduced speed so as to form a fluidized bed of said refractory particles therein, and to ensure that the hot gases have a temperature higher than the vaporization temperature of said refractory material, controlling the rate of introduction of said refractory material in said plasma flow to allow for the vaporization of at least part of said coarse refractory particles in the fluidized bed, and removing hot gases containing vaporized refractory materials and fine refractory particles entrained therein from above said fluidized bed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |