# US 4,399,546 A · Silicon carbide furnace

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- Number: US 4,399,546 A
- Document ID: US4399546A
- Status: Granted
- Kind: A
- Application number: 06/283,696
- Filed: 1981-07-15
- Granted: 1983-08-16
- Earliest claimed: 1979-09-28
- Assignees: Dresser Industries, Inc.
- Inventors: James D. Phillips
- Web page: https://patentgrep.com/patent/US4399546A

## CPC

- H05B 3/60: Heating arrangements wherein the heating current flows through granular powdered or fluid material, e.g. for salt-bath furnace, electrolytic heating (H05B3/38 takes precedence)
- C01B 32/963: Preparation from compounds containing silicon
- F27B 21/00: Open or uncovered sintering apparatus; Other heat-treatment apparatus of like construction
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- F27B: FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS

## Abstract

Electrical resistance furnace and manufacturing plant for the preparation of silicon carbide utilizing a resistance core of carbon horizontally inserted within the load and having a broken ring configuration.

## Claims

### Claim 1

A silicon carbide manufacturing plant comprising:
an electrical power source;
a furnace enclosure;
an electrical resistance furnace disposed within the enclosure and operated by electric heating for the preparation of silicon carbide from a load of silicious and carbonaceous material;
the current being supplied by means of electrodes through a resistance core of carbon horizontally inserted within a load, said core and load being of broken ring configuration to define a centrally located circular working space;
means for loading the furnace in said broken ring configuration including a material handling device supported for rotation at the center of said working space for placing said load about said core; and
means for unloading the furnace.

### Claim 2 (depends on 1)

The plant of claim 1 in which the cross-sectional configuration of the furnace is triangular.

### Claim 3 (depends on 1)

The plant of claim 1 wherein the walls of said furnace enclosure are of ring-like configuration and spaced from said furnace for defining a second circular working space concentric to and spaced radially outward from said centrally located working space.

### Claim 4 (depends on 1)

The plant of claim 1 in which said load is free-standing and unrestrained.

### Claim 5

In an electrical resistance furnace operated by electric heating for the preparation of silicon carbide from a free-standing load of silicious and carbonaceous material, the current being supplied by means of electrodes through a resistance core of carbon horizontally inserted within the load, the improvement comprising said core and load being of broken ring configuration for defining a centrally located working space; a material handling device supported for rotation at the center of said working space for placing said load about said core; and said load is free-standing and unrestrained.

### Claim 6 (depends on 5)

The furnace of claim 5 in which the cross-sectional configuration is triangular.

### Claim 7

A silicon carbide maufacturing plant comprising:
a dome defining a non-combustible enclosure and having track means circumferentially connected to the inside surface of the side walls of the dome;
an electrical power source;
a free-standing pile of silicious and carbonaceous material located within the enclosure and being shaped in a broken ring configuration to define a centrally located circular working space;
a source of electrical power including a pair of spaced electrodes;
a resistance core shaped in a broken ring configuration to provide spaced end points and being horizontally inserted within the pile of material, with one of said electrodes being connected to one of said end points and the other of said electrodes being connected to the other of said end points, with electrical current being supplied from said electrical power source through said electrodes to said resistance core to heat said material; and
material handling means for loading said pile of material in said broken ring-like configuration including support means located at the center of said working space and a stacking device having one end rotatably mounted on said support means and including a discharge member for discharging said material as said device is rotated to form said broken ring pile, the other end of said stacking device being supported by said track means for relative movement between said device and said dome.

### Claim 8 (depends on 7)

A plant in accordance with claim 7 wherein said dome prevents all pollutants generated during the loading, heating, and unloading of said material from escaping to the atmosphere; and said plant further includes means disposed within said dome for collecting said pollutants and transferring same to a processing station remote from said dome.

### Claim 9 (depends on 7, 8)

A plant in accordance with claims 7 or 8 wherein said dome is a geodesic dome.

### Claim 10 (depends on 7)

A plant in accordance with claim 7 wherein the walls of said dome are spaced from said free-standing pile for defining a second circular working space concentric to and spaced radially outward from said centrally located working space.