RU2118290C1 - Device for producing heat-expansion graphite - Google Patents

Abstract

FIELD: metallurgy, thermal and electrical engineering, chemical mechanical engineering; production of flexible graphite parts, composite materials, catalysts, seals, antifriction and heat-insulating materials. SUBSTANCE: device has vertical cylindrical chamber 1 with two gas burners 2, pipe connection 3 for feeding half-finished graphite, and bottom 6 mounted for vertical displacement. Burners 2 are relatively spaced apart through angle α of 15 to 100 deg.; pipe connection 3 is installed between burners 2. Temperature in mixed-flame zone is at least 1000 C. Ash content of heat-expansion graphite is lower than 2 mass percent, its bulk density is 2-4 kg/cu. m, pH of aqueous extract is 6.7-6.9; fuel gas flow rate is maximum 0.2 cu. m per 1 kg of graphite. EFFECT: improved quality of graphite; enlarged functional capabilities of device. 2 cl, 2 dwg

Description

 The claimed invention relates to the technology of carbon-graphite materials, in particular to devices for thermally expanded graphite used in the manufacture of highly conductive flexible products, composites with a high specific surface, catalysts, gaskets, seals and coatings in chemical devices, antifriction and heat-protective materials for various industries metallurgy, heat engineering, chemical engineering, electrical engineering, etc.

 An analogue of the claimed invention is a furnace, which is a cylindrical chamber shaft type with a gas burner located in its lower part and an opening for loading pre-treated with sulfuric acid, washed and dehydrated to a free-flowing state of graphite and introducing air (French patent N 1585066, class C 01 B , 1970).

 The essential features of the analog "vertical expansion chamber" and "gas burner" coincide with the essential features of the claimed invention.

 This device, having low productivity, provides graphite of good quality, but with a high residual content of sulfur compounds.

 Another analogue of the proposed technical solution is a device for producing thermally expanded graphite, consisting of a combustion chamber with a gas burner and gas distribution grid, a vertical expansion chamber with a fluidized bed of a granular coolant, an calcination chamber with two burners, a loading pipe and a gas duct for exhausting the gas flow from the installation (and USSR N 1664743, class C 01 B 31/04, 1991).

 The essential features of the analogue "vertical expansion chamber", "calcination chamber", "gas burners" and "loading pipe" coincide with the essential features of the claimed invention.

 With high installation performance, there is a complexity of hardware design and a large energy intensity of the process.

 The closest analogue of the present invention is a device for producing thermally expanded graphite, consisting of a sublattice chamber equipped with an air duct, a vertical cylindrical expansion chamber equipped with two gas burners and a gas distribution grid separated from the sublattice chamber, over which a layer of an inert coolant, an annealing chamber, and a supply pipe are located graphite intermediate (A.S. USSR N 1761667, class C 01 B 31/04, 1992).

 The essential features of the closest analogue “vertical cylindrical expansion chamber with two gas burners”, “calcination chamber” and “pipe for feeding graphite intermediate” coincide with the essential features of the proposed device.

 However, the product obtained in the known device contains ash and sulfur compounds in significant quantities.

 The problem to which the invention is directed, is to improve the quality of thermally expanded graphite by reducing the ash content and the content of sulfur compounds. Another type of technical result, the receipt of which can provide the claimed invention in comparison with the closest analogue, is to reduce the energy intensity of the process.

To achieve the technical result, the device for producing thermally expanded graphite contains a vertical cylindrical expansion chamber equipped with two gas burners installed at an angle α from 15 ^o to 100 ^{o to} each other, and a pipe placed in the range of the latter, and an annealing chamber sequentially located behind it .

 Significant distinguishing features from the closest analogue of the features of the proposed device are expressed in the installation of gas burners at an angle to each other and the placement of the pipe between them.

 To increase the performance of the device under the expansion chamber has the ability to move vertically.

 The invention is illustrated by drawings, where in FIG. 1 shows a device for producing thermally expanded graphite, front view; in FIG. 2 is a section along AA in FIG. one.

The device comprises a vertical cylindrical expansion chamber 1 with two gas burners 2 and a pipe 3 for supplying graphite intermediate. The burners 2 are installed at an angle α from 15 to 100 ^{o to} each other, and the nozzle 3 is placed in the alignment of the burners 2. The expansion chamber 1 is connected in series with the calcination chamber 4 and the gas duct 5. A feed system is connected to the device for feeding the expansion chamber 1 through the nozzle 3 , the separation system of the exhaust gas stream and expanded graphite and the receiver-drive of the finished product (Fig. not shown).

When installing the burner 2 at an angle α from 15 to 100 ^o in the zone of the torches maintained constant temperature; when the location of the burners 2 at an angle α less than 15 ^o and more than 100 ^o , the stability of the bulk density of expanded graphite and the productivity of the device (at α> 100 ^o ) are reduced.

 In order to clean the hearth 6, the expansion chamber 1 from ash during installation operation has the ability to move vertically.

The device works as follows: fuel gas is mixed with air, blown through burners 2 and set on fire in the nozzles of the latter. Dried oxidized graphite is charged through pipe 3, compressed air picks up the graphite intermediate and feeds it into the confluence zone of two flares, the temperature of which is 1000 ^o C and above. The graphite sprayed in the air stream is heated at high speed to the temperature of the coolant and foams. At the same time, water, sulfuric acid, its decomposition products are released from it, and ash is precipitated here. Then graphite is ejected from the expansion chamber 1 into the calcination chamber 4. The flakes of graphite, expanding, take the form of "worms", they are picked up by the ascending gas flow. In the calcination chamber 4 (temperature 700 - 900 ^o C), the residues of sulfuric acid are removed from the expanded graphite flakes, and they, together with the exhaust gases, are sent through a gas duct 5 to a mesh filter, through which gases are removed for cleaning in a scrubber, and graphite is deposited in a receiver storage device.

Thus, the claimed device allows to obtain thermally expanded graphite with an ash content of less than 2 wt.% With an initial ash content of graphite intermediate 7 wt. %, bulk density of 2 - 4 kg / m ³ , the pH of the aqueous extract of 6.7 - 6.9 and reduce the energy intensity of the process of its production by reducing the consumption of fuel gas to 0.2 m ³ / kg of graphite.

Claims (1)

 \ \ \ 1 1. Device for producing thermally expanded graphite, containing a vertical cylindrical expansion chamber equipped with two gas burners, and an annealing chamber sequentially located behind it, a pipe for supplying graphite intermediate, characterized in that the burners are installed at an angle of $$$ from 15 to 100 <198> to each other, and the pipe is placed in the alignment of the burners. \\\ 2 2. The device according to claim 1, characterized in that under the expansion chamber has the ability to move vertically.

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