CA1156424A
Expired / Lapsed
CA
⏱️ 0.0 years remaining
Methods and apparatus for the continuous production of carbides
Assignee: Individual
•
Filing: 1981-02-05
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Granted: 1983-11-08
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Expires: 2001-02-05
Abstract
Abstract IMPROVED METHODS AND APPARATUS FOR THE CONTINUOUS PRODUCTION OF CARBIDES ABSTRACT OF THE DISCLOSURE One aspect of the present invention relates to methods for the continuous production of silicon carbide and other carbide and refractory products by fluidized bed tech-niques, the apparatus for such continuous production, and the carbide products produced therefrom being further aspects of the present invention.
Inventors
- 👤 William M. Goldberger
Bibliographic Details
Application Number
—
Jurisdiction
CA
Data Source
google_patents
Last Synchronized
2026-11-03 05:18
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/97
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
112 words
The method of making a silicon carbide-bearing material comprising the steps of: continuously introducing silicon-bearing and carbon-bearing materials into a fluidized bed of electrically conductive particulate material; maintaining the bed in the fluidized condition by controlling the flow rate of gases entering beneath the fluidized bed; applying an electric potential between electrodes in direct contact with the particles of the fluidized bed to cause a sufficient flow of electrical current through the fluidized bed to heat the bed to a temperature level ade-quate for the reaction of the silicon-bearing material and the carbon-bearing material to form a silicon carbide-bearing material; continuously removing the silicon carbide bearing solids from the fluidized bed furnace.
Claim 2
Independent Claim
112 words
The method of making a silicon carbide-bearing material comprising the steps of: continuously introducing silicon-bearing and carbon-bearing materials into a fluidized bed of electrically conductive particulate material; maintaining the bed in the fluidized condition by controlling the flow rate of gases entering beneath the fluidized bed; applying an electric potential between electrodes in direct contact with the particles of the fluidized bed to cause a sufficient flow of electrical current through the fluidized bed to heat the bed to a temperature level ade-quate for the reaction of the silicon-bearing material and the carbon-bearing material to form a silicon carbide-bearing material; continuously removing the silicon carbide bearing solids from the fluidized bed furnace.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the silicon-bearing and carbon-bearing materials are introduced as indi-vidual free-flowing granular solids.
Claim 4
Dependent Claim
23 words
The method of claim 1 wherein the silicon-bearing and carbon-bearing materials are premixed and intro-duced together as a dry free-flowing granular solid mixture.
Claim 5
Dependent Claim
21 words
The method of claim 3 wherein the silicon-bearing and carbon-bearing material mixture is agglomerated before being introduced into the fluidized bed.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein the fluidizing gas is nitrogen.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein the fluidizing gas is carbon monoxide.
Claim 8
Dependent Claim
26 words
The method of claim 1 wherein the fluidizing gas is obtained by recirculating a portion of the gases generated by the chemical reaction within the furnace.
Claim 9
Dependent Claim
24 words
The method of claim 1 wherein the silicon-bearing material is a fine powder comprising particles having a diameter of less than about 10 microns.
Claim 10
Dependent Claim
24 words
The method of claim 1 where the carbon-bearing material is a fine powder comprising particles having a diameter of less than about 10 microns.
Claim 11
Dependent Claim
14 words
The method of claim 1 wherein the silicon-bearing material is introduced in liquid form.
Claim 12
Dependent Claim
15 words
The method of claim 1 wherein the silicon-bearing material is introduced in the gaseous state.
Claim 13
Dependent Claim
18 words
The method of claim 1 wherein the carbon-bearing material is introduced in the form of a hydrocarbon liquid.
Claim 14
Dependent Claim
15 words
The method of claim 1 wherein the carbon-bearing material is introduced as a hydrocarbon vapor.
Claim 15
Dependent Claim
16 words
The method of claim 1 wherein the carbon-bearing material is introduced as green (uncalcined) petroleum coke.
Claim 16
Dependent Claim
30 words
The method of claim 1 wherein the silicon carbide-bearing material formed within the furnace is re-moved through a discharge opening located at the bottom of the bed of fluidized material.
Claim 17
Dependent Claim
31 words
The method of claim 1 wherein the silicon carbide-bearing material formed within the furnace is re-moved through a discharge opening located at some elevation above the bottom of the fluidized bed.
Claim 18
Dependent Claim
43 words
The method of claim 1 wherein the silicon carbide-bearing material formed within the furnace is re-moved by elutriation from the upper portion of the fluidized bed and carried out of the furnace by entrainment within the gaseous effluent leaving the fluidized bed furnace.
Claim 19
Independent Claim
302 words
The method of making silicon carbide-bearing material comprising the steps of: introducing into a heat resistant vessel a rela-tively coarse particulate carbon-bearing material; introducing a sufficient flow of non-reactive gas through a gas distribution member to bring the particulate carbon-bearing material into the state of fluidization; applying an electric potential between electrodes positioned to be in direct contact with the fluidized carbon-bearing material particles to cause electric current to flow through the bed material between the electrodes in direct contact with the fluidized bed and at a rate sufficient to heat the said fluidized bed to a temperature in excess of the temperature of decomposition of silicon carbide; introducing a finer particulate carbon-bearing material into the fluidized bed of coarser particulate carbon-bearing material; controlling the relative size difference of the coarser and finer particulate carbon-bearing material and the velocity of the fluidizing gas to cause the finer particulate carbon-bearing material to be maintained in a state of dense phase fluidization in a region above the fluidized bed of the coarser particulate carbon-bearing material; removing heat from the zone of the fluidized bed of the finer particulate carbon-bearing material sufficient to cause the temperature of the fluidized bed of the finer particu-late carbon-bearing material to be lower than the temperature of the fluidized bed of the coarser particulate carbon-bearing material and below that of the decomposition temperature of silicon carbide, but above that temperature required to form silicon carbide by the reaction of vapor forms of silicon and solid carbon; introducing a silicon-bearing material into the fluidized bed of coarser particulate carbon-bearing material to cause silicon vapors to form and to pass upwardly through the lower temperature fluidized bed of finer particulate carbon-bearing material and to react with the finer carbon-bearing material to form a silicon carbide-bearing material from the fluidized bed furnace.
Claim 20
Independent Claim
302 words
The method of making silicon carbide-bearing material comprising the steps of: introducing into a heat resistant vessel a rela-tively coarse particulate carbon-bearing material; introducing a sufficient flow of non-reactive gas through a gas distribution member to bring the particulate carbon-bearing material into the state of fluidization; applying an electric potential between electrodes positioned to be in direct contact with the fluidized carbon-bearing material particles to cause electric current to flow through the bed material between the electrodes in direct contact with the fluidized bed and at a rate sufficient to heat the said fluidized bed to a temperature in excess of the temperature of decomposition of silicon carbide; introducing a finer particulate carbon-bearing material into the fluidized bed of coarser particulate carbon-bearing material; controlling the relative size difference of the coarser and finer particulate carbon-bearing material and the velocity of the fluidizing gas to cause the finer particulate carbon-bearing material to be maintained in a state of dense phase fluidization in a region above the fluidized bed of the coarser particulate carbon-bearing material; removing heat from the zone of the fluidized bed of the finer particulate carbon-bearing material sufficient to cause the temperature of the fluidized bed of the finer particu-late carbon-bearing material to be lower than the temperature of the fluidized bed of the coarser particulate carbon-bearing material and below that of the decomposition temperature of silicon carbide, but above that temperature required to form silicon carbide by the reaction of vapor forms of silicon and solid carbon; introducing a silicon-bearing material into the fluidized bed of coarser particulate carbon-bearing material to cause silicon vapors to form and to pass upwardly through the lower temperature fluidized bed of finer particulate carbon-bearing material and to react with the finer carbon-bearing material to form a silicon carbide-bearing material from the fluidized bed furnace.
Claim 21
Independent Claim
21 words
The method of claim l wherein the silicon carbide-bearing material formed is beneficated by separation of carbon from the silicon carbide.
Claim 22
Dependent Claim
21 words
The method of claim 18 wherein the silicon carbide-bearing material formed is beneficated by separation of carbon from the silicon carbide.
Claim 23
Dependent Claim
20 words
The method of claim 1 wherein the silicon-bearing and carbon-bearing materials are introduced as chemical compounds containing silicon and carbon.
Claim 24
Dependent Claim
19 words
The method of claim 1 wherein the silicon-bearing and carbon-bearing materials are introduced as materials of natural organic origin.
Claim 25
Dependent Claim
32 words
The method of claim 22 wherein the materials of natural organic material are selected from the group con-sisting of coal, coke, natural graphite, chars made from coal, wood chars, and rice hulls.
Claim 26
Dependent Claim
19 words
The method of claim 22 wherein a natural organ-ic material including fibers containing both silica and carbon are introduced.
Claim 27
Dependent Claim
186 words
The furnace apparatus for producing silicon carbide-bearing material comprising: a fluidization vessel having walls made of heat resistant and electrically conductive electrode material and having a lower zone of relatively small cross-sectional area and upper zone of relatively larger cross-sectional area con-nected by a transition section; an aperture for introducing coarse and fine carbonaceous solids into the fluidization vessel; means for distributing fluidizing gas to the bottom of the vessel and for controlling the gas flow rate thereby to fluidize the carbonaceous solids; electrodes entering from the top of the furnace and extending vertically downward into the lower zone of smaller cross-sectional area; a discharge port to remove solids from the upper layer larger cross-sectional area zone; means to control solid removal rate; means to introduce a silicon-bearing material into the lower fluidized bed zone; an opening in the vessel to remove gases from the furnace; and means to apply sufficient electrical voltage between electrodes to cause current to flow through the fluidized bed in the lower smaller cross-sectional area fluidized zone whereby greater temperatures are attained in said lower zone than in said upper zone.
Claim 28
Dependent Claim
186 words
The furnace apparatus for producing silicon carbide-bearing material comprising: a fluidization vessel having walls made of heat resistant and electrically conductive electrode material and having a lower zone of relatively small cross-sectional area and upper zone of relatively larger cross-sectional area con-nected by a transition section; an aperture for introducing coarse and fine carbonaceous solids into the fluidization vessel; means for distributing fluidizing gas to the bottom of the vessel and for controlling the gas flow rate thereby to fluidize the carbonaceous solids; electrodes entering from the top of the furnace and extending vertically downward into the lower zone of smaller cross-sectional area; a discharge port to remove solids from the upper layer larger cross-sectional area zone; means to control solid removal rate; means to introduce a silicon-bearing material into the lower fluidized bed zone; an opening in the vessel to remove gases from the furnace; and means to apply sufficient electrical voltage between electrodes to cause current to flow through the fluidized bed in the lower smaller cross-sectional area fluidized zone whereby greater temperatures are attained in said lower zone than in said upper zone.
Claim 29
Dependent Claim
16 words
The furnace apparatus of claim 25 wherein said discharge port is disposed in the vessel wall.
Claim 30
Dependent Claim
32 words
The furnace apparatus of claim 26 wherein the discharge port has an opening into the vessel disposed within the upper zone of larger cross-sectional area near the surface of the fluidized bed.
Claim 31
Dependent Claim
46 words
The furnace apparatus of claim 25 wherein the means for distributing the fluidizing gas to the bottom of the vessel and for controlling the flow rate thereof comprises: a distributor plate disposed at the bottom of said lower zone and having a multiplicity of gas orifices.
Claim 32
Dependent Claim
23 words
The furnace apparatus of claim 25 wherein said means to control the solid removal rate comprises: a valve connected to the discharge port.
Claim 33
Dependent Claim
25 words
The furnace apparatus of claim 25 wherein said downwardly extending electrode contains therein a longitudin-al passage for the introduction of further coarse carbonaceous solids therethrough.
Claim 34
Dependent Claim
27 words
The furnace apparatus of claim 25 wherein said means for introducing a silicon-bearing material comprises: a conduit pipe disposed to enter the vessel within said lower zone.
References Cited (Backward Citations)
No citation records indexed.
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