GB2604978A

GB2604978A - Graphite crucible for carbon extraction and horizontal induction heating graphitization furnace

Info

Publication number: GB2604978A
Application number: GB2117172.3A
Authority: GB
Inventors: Lam Stephanie Mak Yeuk
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-08-02
Filing date: 2021-11-29
Publication date: 2022-09-21
Anticipated expiration: 2041-11-29
Also published as: CN113532113A; GB202117172D0; GB2604978B; GB202210555D0

Abstract

Graphite crucible (1, fig. 4) for carbon extraction, comprising a graphite cylinder 11 having a cylindrical groove 12 formed therein, arranged in the same direction as the graphite cylinder. The groove being arranged to accommodate samples. At least one side of the groove is provided with a through-hole 13, potentially coaxial with the groove, and communicating with outside the cylinder. The diameter of the through-hole being smaller than the inner diameter of the groove. The graphite cylinder may be a rectangular parallelpiped shape with square faces. The other side of the groove may be closed and be provided with a bump 14 of equal diameter to the through-hole and coaxial therewith. A horizontal induction heating graphitization furnace is also claimed, having a furnace body (5, fig. 4) and drive device (7, fig. 6) to rotate the furnace body alternately. An induction coil (4, fig. 4), insulation layer (3, fig. 4) and thermal insulation layer (2, fig. 4) would also be sequentially arranged. The crucible would be arranged in a cavity formed in the thermal insulation. Another graphitization furnace is also claimed.

Description

Specification

Graphite Crucible for Carbon Extraction and Horizontal Induction Heating Graphitization Furnace

Field of the Invention

The present invention relates to the technical field of graphitization equipment, in particular to a graphite crucible for carbon extraction and a horizontal induction heating graphitization furnace.

Background of the Invention

The extraction of carbon from carbon-containing biological samples such as hair and ashes is a pre-process for the cultivation of memorial diamonds. The purity of carbon and the degree of graphitization achieved in this process determine the final quality of memorial diamonds.

Graphitization of biological samples is a process through which dried and powdered biological samples are treated by thermal radiation heating at 2000°C-3000°C for graphitization under inert gas protection. This process cannot be performed without a graphitization furnace. Currently, horizontal induction heating graphitization furnaces comprise an induction coil, a graphite crucible, an insulated furnace and other components. With this process, samples are placed in the graphite crucible. When the induction coil is energized, it generates a high-frequency magnetic field and induced current is generated on the side wall of the graphite crucible to heat the graphite crucible, so carbon-containing samples are graphitized by thermal radiation heating at a high temperature.

Previous horizontal in ducti on heatin g graphiti zati on furnaces are mostly industrial furnaces with large and flat inner space, which results in that carbon can only be extracted from single powdered carbon-containing samples at a time rather than in batches, with low efficiency of extraction because powdered samples mainly absorb heat from parts in contact with graphite crucible and cannot flip themselves during heating and extraction.

Summary of the Invention

To solve the defects existing in the prior art, the present invention provides a graphite crucible for carbon extraction and a horizontal induction heating graphitization furnace, which can be used to extract carbon from multiple samples at one time, and rotate the furnace body clockwise and counterclockwise alternately by a drive device thus to turn over samples in the graphite crucible to improve the extraction efficiency.

The technical scheme of the present invention is as follows: For one thing, the present invention provides a graphite crucible for carbon extraction comprising a solid graphite cylinder. A cylindrical groove is opened in the graphite cylinder. The cylindrical groove is arranged in the same direction as the graphite cylinder. The circular groove is arranged to accommodate samples from which carbon is to be extracted. At least one side of the cylindrical groove is provided with a through hole communicating with the outside of the graphite cylinder. The diameter of the through hole is smaller than the inner diameter of the cylindrical groove.

Preferably, the cylindrical groove is arranged coaxially with the graphite cylinder.

Preferably, the graphite cylinder is a rectangular parallelepiped in shape with square faces with a side length of 380 mm The diameter of the cylindrical groove is 300 mm. The through hole is a round hole with a diameter of 150 mm.

Preferably, one side of the cylindrical groove is provided with a through hole, and the other side is closed. One side of the graphite cylinder close to the closed side of the cylindrical groove is provided with a bump. The through hole, the bump, and the cylindrical groove are arranged coaxially. The outer diameter of the bump matches the inner diameter and length of the through hole.

For another thing, the present invention provides a horizontal induction heating graphitization ftimace, comprising a furnace body and a drive device. The drive device is arranged to drive the furnace body to rotate clockwise and counterclockwise alternately. An induction coil, an insulation layer, and a thermal insulation layer are sequentially arranged in the furnace body from outside to inside. An accommodating cavity is arranged in the thermal insulation layer, and at least one graphite crucible described above is arranged in the accommodating cavity.

Preferably, the thermal insulation layer comprises graphite soft carbon felt and graphite hard carbon felt. The graphite hard carbon felt is wrapped outside the accommodating cavity in one layer with a thickness of 70 mm The graphite soft carbon felt is wrapped outside the graphite hard carbon felt in 11 layers with a total thickness of 110 mm.

Preferably, the insulation layer is built with staggered double-layer corundum bricks with a thickness of 60mm The induction coil is made by winding a rectangular copper tube that has gone through the procedures of spraying heat-resistance ceramic insulating paint, winding insulating gold film, and winding insulating glass fabric tape, inside which cooling water flows through, and outside which a pipe connector is arranged.

Preferably, the furnace body adopts a double-layer stainless steel sandwich water-cooling structure, which can be vacuumed (under negative pressure), and is provided with an explosion-proof vent, a vacuum pipe interface, a vacuum breaker valve, an air pressure relief valve, an inflation hole and a vacuum gauge.

Preferably, several graphite crucibles I are arranged coaxially with one graphite crucible II in the accommodating cavity. One side of the cylindrical groove of the graphite crucible I is provided with a through hole, and the other side is closed and provided with a bump. At least one side of the cylindrical groove of the graphite crucible II is provided with a through hole, and the bump of the graphite crucible I matches the through hole of the graphite crucible II. The bump of the first graphite crucible I is inserted into the though hole of the graphite crucible II. The bump of the next graphite crucible I is inserted into the though hole of the previous graphite crucible I, and so on to form a whole body.

Preferably, both ends of the furnace body are fixedly connected with a detachable furnace cover. Both ends of the furnace body are respectively provided with a drive device. Each of the drive devices comprises a 1/4 arc-shaped groove, a slider, and a support drive part. The 1/4 arc-shaped groove is opened on the outer surface of the furnace cover. An island platform in a shape matched with the 1/4 arc-shaped groove is arranged therein. A fixed part in a shape matched with the island platform is fixedly arranged thereon. The fixed part is uniformly provided with teeth in circumferential direction. The slider can slide in the revolving groove formed by the island platform and the 1/4 arc-shaped groove. In addition, the slider is uniformly provided with teeth in circumferential direction and meshes with the fixed part. The support drive part is arranged to drive the slider to rotate around its own axis and support the slider.

The beneficial effects of the present invention are as follows: Compared with the prior art, the graphite crucible for carbon extraction provided in the present invention is easy to be assembled, disassembled and maintained, and samples are easily placed in or removed from the cylindrical groove through the through hole without leakage during extraction. The horizontal induction heating graphitization furnace provided in the present invention can extract carbon from multiple samples at one time to achieve bulk extraction and alternately clockwise and counterclockwise rotation of the furnace body by the drive device thus to turn over samples in the graphite crucible, which improves efficiency and reduces cost of the extraction.

Description of the Drawings

In order to more clearly illustrate the specific embodiments of the present invention or technical scheme in the prior art, the specific embodiments or drawings required for description of the prior art will be briefly introduced below. Similar reference numerals are generally used throughout the drawings to indicate similar elements or parts. Elements or parts in the drawings are not necessarily drawn to scale.

Fig. 1 is a side cross-sectional view of the graphite crucible provided by an embodiment of the present invention; Fig. 2 is a longitudinal section view of the graphite crucible shown in Fig. 1; Fig. 3 is a longitudinal section view of the graphite crucible provided by another embodiment of the present invention; Fig. 4 is a side cross-sectional view of the horizontal induction heating graphitization furnace provided by an embodiment of the present invention; Fig. 5 is a longitudinal section view of the horizontal induction heating graphitization furnace shown in Fig. 4 (the drive device is not indicated); Fig. 6 is a longitudinal section view of the horizontal induction heating graphitization furnace provided by another embodiment of the present invention; Fig. 7 is a side view of the furnace cover of the horizontal induction heating graphitization furnace shown in Fig. 6; Fig. 8 is a structural schematic diagram of the support drive part of the horizontal induction heating graphitization furnace shown in Fig. 6.

Description of the reference numerals: 1-graphite crucible; 11-graphite cylinder; 12-cylindrical groove; 13-through hole; 14-bump; 101-graphite crucible I; 102-graphite crucible II; 2-thermal insulation layer; 21-graphite hard carbon felt; 22-graphite soft carbon felt; 3-insulation layer; 4-induction coil; 5-furnace body; 6-furnace cover; 61-limit device; 7-drive device; 71-arc-shaped groove; 72-revolving groove; 73-fixed part; 74-slider; 751-motor; 752-coupling; 753-sliding part; 754-guide frame.

Detailed Description of Preferred Embodiments

The embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical scheme of the present invention, so they are examples and not intended to limit the scope of protection of the present invention.

It should be noted that, unless otherwise stated, the technical terms or scientific terms used herein should have the ordinary meanings understood by those skilled in the art of the present invention.

Embodiment l The present embodiment provides a graphite crucible (1) for carbon extraction, as shown in Figs. 1-2, it comprises a solid graphite cylinder (11). A cylindrical groove (12) is opened in the graphite cylinder (11). The cylindrical groove (12) is arranged in the same direction as the graphite cylinder (11). The circular groove is arranged to accommodate samples from which carbon is to be extracted. At least one side of the cylindrical groove (12) is provided with a through hole (13) communicating with the outside of the graphite cylinder (11). The diameter of the through hole (13) is smaller than the inner diameter of the cylindrical groove (12). Compared with the prior art, the graphite crucible (1) with such a structure is easy to be assembled, disassembled and maintained. Samples are easily placed in or removed from the cylindrical groove (12) through the through hole (13) without leakage during extraction.

In the present embodiment, the cylindrical groove (12) is preferably arranged coaxially with the graphite cylinder (i1). The graphite cylinder (11) is preferably a rectangular parallelepiped with square faces with a side length of 380 mm The diameter of the cylindrical groove (12) is preferably 300 mm The through hole (13) is preferably a round hole with a diameter of preferably 150 mm Embodiment 2 In the present embodiment, as shown in Fig. 3, only one side of the cylindrical groove (12) of the graphite crucible (1) is provided with a through hole (13), and the other side is closed. A bump (14) is arranged on the side of the graphite cylinder (11) close to the closed side of the cylindrical groove (12). The through hole (13), the bump (14) and the cylindrical groove (12) are arranged coaxially. The outer diameter of the bump (14) matches the inner diameter and length of the through hole (13). With such a design, multiple graphite crucibles (1) can form a whole body by assembly, which makes it possible to process multiple samples at one time and is convenient for assembly and disassembly. The bump (14) also plays a role in blocking the through hole (13) to reduce loss of powdered samples caused by leakage.

Embodiment 3 The present embodiment provides a horizontal induction heating graphitization furnace comprising a furnace body (5) and a drive device (7), as shown in Figs. 4-5. The drive device (7) is arranged to drive the furnace body (5) to rotate around its axis clockwise and counterclockwise alternately. The angle of rotation is preferably 45° for clockwise rotation and counterclockwise rotation respectively. An induction coil (4), an insulation layer (3), and a thermal insulation layer (2) are sequentially arranged in the furnace body (5) from outside to inside. An accommodating cavity is arranged in the thermal insulation layer (2), and at least one graphite crucible (1) described above is arranged in the accommodating cavity. Preferably, multiple graphite crucibles (1) are arranged to achieve processing of multiple samples at one time and clear source of multiple samples to avoid mix-ups. The furnace body (5) can be rotated clockwise and counterclockwise alternately by the drive device (7), which drives the graphite crucible (1) arranged therein to rotate thus to turn over powdered samples in the graphite crucible (1) for uniform heating. The cylindrical groove (12) is arranged to hold samples and its curved sidewall helps achieve better turn-over when being rotated.

In the present embodiment, the thermal insulation layer (2) comprises graphite soft carbon felt (22) and graphite hard carbon felt (21). The graphite hard carbon felt (21) is wrapped outside the accommodating cavity in one layer with a thickness of 70 mm. The graphite soft carbon felt (22) is wrapped outside the graphite hard carbon felt (21) in 11 layers with a total thickness of 110 mm With such a design, the thermal insulation layer (2) is resistant to high temperature and corrosion, elastic for better wrapping the accommodating cavity to achieve a good thermal insulation effect.

In the present embodiment, the insulation layer (3) is built with staggered double-layer corundum bricks with a thickness of 60 mm Corundum bricks refer to refractory products with alumina content greater than 90% and corundum as the main crystal phase, which have good chemical stability and strong resistance to acidic or alkaline slag, metal and molten glass. The induction coil (4) is made by winding a rectangular copper tube that has gone through the procedures of spraying heat-resistance ceramic insulating paint, winding insulating gold film, and winding insulating glass fabric tape, inside which cooling water flows through, and outside which a pipe connector is arranged.

In the present embodiment, the furnace body (5) adopts a double-layer stainless steel sandwich water-cooling structure with a thickness of 1 Omm, which can be vacuumed (under negative pressure), and is provided with an explosion-proof vent, a vacuum pipe interface, a vacuum breaker valve, an air pressure relief valve, an inflation hole and a vacuum gauge.

Embodiment 4 The present embodiment, on the basis of Embodiment 3, as shown in Fig. 6, makes further improvements that several graphite crucibles I (101) are arranged coaxially with one graphite crucible II in the accommodating cavity. One side of the cylindrical groove (12) of the graphite crucible I (101) is provided with a through hole (13), and the other side is closed and provided with a bump (14). At least one side of the cylindrical groove (12) of the graphite crucible II (102) is provided with a through hole (13), and the bump (14) of the graphite crucible I (101) matches the through hole (13) of the graphite crucible II (102). The bump (14) of the first graphite crucible I (101) is inserted into the through bole (13) of the graphite crucible II (102). The bump (14) of the next graphite crucible I (101) is inserted into the through hole (13) of the previous graphite crucible I (101), and so on to form a whole body.

In the present embodiment, both ends of the furnace body (5) are fixedly connected with a detachable furnace cover (6). A limit device (61) can be arranged on the furnace cover (6) for limiting the group of graphite crucibles (1) described above to stabilize the group of graphite crucibles (1) during extraction.

Embodiment 5 In the present embodiment, both ends of the furnace body (5) are respectively provided with a drive device (7). As shown in Figs. 7-8, each of the drive devices (7) comprises a 1/4 arc-shaped groove (71), a slider (74), and a support drive part. The 1/4 arc-shaped groove (71) is opened on the outer surface of the furnace cover (6). An island platform in a shape matched with the 1/4 arc-shaped groove (71) is arranged therein. A fixed part (73) in a shape matched with the island platform is fixedly arranged thereon. The fixed part (73) is uniformly provided with teeth in circumferential direction. The slider (74) can slide in the revolving groove (72) formed by the island platform and the 1/4 arc-shaped groove (71). In addition, the slider (74) is uniformly provided with teeth in circumferential direction and meshes with the fixed part (73). The support drive part is arranged to drive the slider (74) to rotate around its own axis and support the slider (74). The support drive part comprises a motor (751), a guide frame (754) and a coupling (752). The coupling (752) is preferably a Weiss joint. The motor (751) is fixedly arranged and its output shaft transmits power to the slider (74) through the coupling (752). The output end of the coupling (752) is sleeved with a sliding part (753) which is rotatably connected with the output end of the coupling (752). The sliding part (753) is sleeved on the guide frame (754) which is used to restrict the sliding part (753) for only sliding up and down. When the motor starts, the motor drives the slider (74) to rotate through the coupling. The slider (74) meshes with the fixed part (73) and the slider (74) drives the furnace cover (6) to rotate. The relative positions of the revolving groove (72) and the slider (74) changes. When passing through a turning, the slider (74) drops and the sliding part (753) drops from the guide frame (754), and then the furnace cover (6) reversely rotates by the same angle. Both the furnace covers (6) move simultaneously to drive the furnace body (5) to rotate clockwise and counterclockwise by 45° alternately to turn over powdered samples and make them more evenly heated.

In order to ensure the stability of the furnace body (5) during rotation, support devices can be arranged for supporting the furnace body (5), such as a bearing seat, which supports the weight of the furnace body without causing interference with its rotation. In the same way, support devices can be a curved base with several balls arranged on the curved surface, through which the furnace body (5) can rotate relative to the curved base.

Finally, it should be noted that various embodiments described above are only for illustration of the technical scheme of the present invention, but not limitation. While the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that they can still modify the technical scheme provided in the foregoing embodiments, or make equivalent replacement of some or all technical features included therein. Such modifications or replacements should not cause corresponding technical scheme to intrinsically deviate from the scope of the technical scheme provided in the embodiments herein, and shall be included in the scope of the claims and specification of the present invention.

Claims

Claims 1. A graphite crucible for carbon extraction, characterized in that it comprises a solid graphite cylinder; a cylindrical groove is opened in the graphite cylinder; the cylindrical groove is arranged in the same direction as the graphite cylinder; the circular groove is arranged to accommodate samples from which carbon is to be extracted; at least one side of the cylindrical groove is provided with a through hole communicating with the outside of the graphite cylinder; the diameter of the through hole is smaller than the inner diameter of the cylindrical groove.
2. A graphite crucible according to claim 1, characterized in that the cylindrical groove is arranged coaxially with the graphite cylinder.
3. A graphite crucible according to claim 2, characterized in that the graphite cylinder is a rectangular parallelepiped in shape with square faces with a side length of 380 mm; the diameter of the cylindrical groove is 300 mm; the through hole is a round hole with a diameter of 150 mm
4. A graphite crucible according to claim 3, characterized in that one side of the cylindrical groove is provided with a through hole, and the other side is closed; one side of the graphite cylinder close to the closed side of the cylindrical groove is provided with a bump; the through hole, the bump, and the cylindrical groove are arranged coaxially; the outer diameter of the bump matches the iimer diameter and length of the through hole.
5. A horizontal induction heating graphitization furnace, characterized in that it comprises a furnace body and a drive device; the drive device is arranged to drive the furnace body to rotate clockwise and counterclockwise alternately; an induction coil, an insulation layer, and a thermal insulation layer are sequentially arranged in the furnace body from outside to inside; an accommodating cavity is arranged in the thermal insulation layer, and at least one graphite crucible as claimed in any one of claims 1 to 4 is arranged in the accommodating cavity.
6. A horizontal induction heating graphitization furnace, characterized in that the theimal insulation layer comprises graphite soft carbon felt and graphite hard carbon felt; the graphite hard carbon felt is wrapped outside the accommodating cavity in one layer with a thickness of 70 mm; the graphite soft carbon felt is wrapped outside the graphite hard carbon felt in 11 layers with a total thickness of 110 mm
7. A horizontal induction heating graphitization furnace according to claim 6, characterized in that the insulation layer is built by staggered double-layer corundum bricks with a thickness of 60mm, the induction coil is made by winding a rectangular copper tube that has gone through the procedures of spraying heat-resistance ceramic insulating paint, winding insulating gold film, and winding insulating glass fabric tape, inside which cooling water flows through, and outside which a pipe connector is arranged.
8. A horizontal induction heating graphitization furnace according to claim 7, characterized in that the furnace body adopts a double-layer stainless steel sandwich water-cooling structure, which can be vacuumed (under negative pressure), and is provided with an explosion-proof vent, a vacuum pipe interface, a vacuum breaker valve, an air pressure relief valve, an inflation hole and a vacuum gauge.
9. A horizontal induction heating graphitization furnace according to claim 8, characterized in that several graphite crucibles I are arranged coaxially with one graphite crucible II in the accommodating cavity; the graphite crucible I is the same as that as claimed in claim 4; the graphite crucible II is the same as that as claimed in claim 1, and the bump of the graphite crucible I matches the through hole of the graphite crucible II; the bump of the first graphite crucible I is inserted into the through hole of the graphite crucible II; the bump of the next graphite crucible I is inserted into the through hole of the previous graphite crucible I, and so on to form a whole body.
10. A horizontal induction heating graphitization furnace according to claim 5, characterized in that both ends of the furnace body are fixedly connected with a detachable furnace cover; both ends of the furnace body are respectively provided with a drive device; each of the drive devices comprises a 1/4 arc-shaped groove, a slider, and a support drive part; the 1/4 arc-shaped groove is opened on the outer surface of the furnace cover; an island platform in a shape matched with the 1/4 arc-shaped groove is arranged therein; a fixed part in a shape matched with the island platform is fixedly arranged thereon; the fixed part is uniformly provided with teeth in circumferential direction; the slider can slide in the revolving groove formed by the island platform and the 1/4 arc-shaped groove; in addition, the slider is uniformly provided with teeth in circumferential direction and meshes with the fixed part; the support drive part is arranged to drive the slider to rotate around its own axis and support the slider.