JP2801930B2 - Graphite powder production equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a graphite powder production apparatus for heating a carbon powder to graphitize it.

"Conventional technology and its problems" As is well known, carbon products are widely used in various fields, and in particular, in recent years, demand for graphite products has been increasing.

By the way, graphite powder, which is a raw material for graphite products, is produced by heating amorphous carbon powder to a high temperature of about 2,000 to 3,000 ° C to graphitize it. Up to now, there has not been provided an effective graphite powder production apparatus which can be converted into a graphite powder. Therefore, the conventional graphite production has been carried out by a batch method. Since one cycle time requires ten and several days, the productivity is remarkably poor. Therefore, it has been difficult to reduce the cost.

The present invention has been made in view of the above circumstances, and has as its object to provide a graphite powder manufacturing apparatus capable of continuously graphitizing carbon powder.

“Means for Solving the Problems” The present invention is a graphite powder manufacturing apparatus for graphitizing by heating carbon powder to a high temperature, comprising a furnace body, and a cylindrical mold penetrating vertically through the furnace body. Heating means provided inside the furnace body for heating the mold from the outside, wherein the heating means heats the carbon powder through the mold while lowering the carbon powder charged therein from the upper end of the mold. By being graphitized by this, it is configured to be taken out from the lower end of the mold, and that a cylindrical core for forming an annular passage having a horizontal cross section in which the carbon powder descends is provided at the axial position of the mold. It is a feature.

In this case, it is preferable that a narrow portion is formed in the passage by providing a step portion bulging radially outward in the core.

Further, it is preferable that a gas blowing means for blowing gas into the passage through a gas blowing pipe provided inside the core is provided.

[Operation] The graphite powder production apparatus of the present invention is configured to continuously charge the raw material carbon powder from the upper end of the mold, to lower the carbon powder by its own weight, and to continuously remove the carbon powder from the lower end of the mold. The mold is heated to a high temperature by a heater, and the carbon powder passing through the inside of the mold is heated by the mold to be graphitized.

By providing a core in the mold, the passage in which the powder descends is formed into an annular horizontal cross section, and the drift of the powder is suppressed by the core. Also, when a step is provided on the core, the weight of the powder is supported by the step to prevent the occurrence of the shelf hanging phenomenon, and
When the powder passes through the narrow portion of the passage formed by the step, the powder is naturally stirred. Further, heat transfer from the mold to the core is promoted through the step portion, so that the core is also heated, and the core also heats the powder.

Embodiment An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an overall schematic configuration of a graphite powder producing apparatus of the present embodiment, and reference numeral 1 in the figure denotes a furnace body. Inside the furnace body 1, a preheating chamber 2 formed of a heat insulating material,
A heating chamber 3 and a pre-cooling chamber 4 are connected in this order from the top, and a heater (heating means) 5 is provided in the heating chamber 3. The furnace body 1 is configured so that its internal air can be replaced with an atmospheric gas (generally an inert gas such as nitrogen or argon).

A charging chamber 6 connected to the preheating chamber 2 is provided at an upper portion of the furnace body 1, and a charging hopper 7 is further provided above the charging chamber. A supply pipe 8 for carbon powder C as a raw material is connected to the charging hopper 7, and a bell-shaped valve 9 is movable between the charging hopper 7 and the charging chamber 6 by a driving device 10. Is provided.

On the other hand, a cooling chamber 11 connected to the pre-cooling chamber 4 is provided at a lower portion of the furnace body 1, and a discharge hopper 12 is further provided below the cooling chamber 11, and a funnel-shaped discharge port 13 is provided therebetween. At the same time, a screw feeder 14 for taking out graphite powder B as a product is attached to a lower portion of the discharge hopper 12. The wall surface of the cooling chamber 11 has a water-cooling structure, and a cooling fin (not shown) is provided inside the cooling chamber 11.
Is forcibly cooled.

At the center of the furnace body 1, a long cylindrical mold penetrating the furnace body 1 vertically and having an upper end opening to the charging chamber 6 and a lower end opening to the cooling chamber 11. 15 are provided. The mold 15 is formed by, for example, graphite, and a portion located inside the heating chamber 3 is heated by the heater 5 located outside the heating chamber 3, whereby the heating chamber 3 The temperature of the intermediate portion is heated to a temperature required for graphitizing the carbon powder C, for example, a temperature of about 2,000 ° C. to 3,000 ° C. The mold 15 is heated to such a temperature by heating the portion located in the heating chamber 3, so that not only the inside of the heating chamber 3 but also the upper and lower portions thereof, that is, the preheating chamber 2 and The temperature of the portion located in the pre-cooling chamber 4 also becomes high, but the temperature gradually decreases toward the upper end and the lower end of the mold 15.

Further, a long cylindrical core 16 is provided at an axial center position in the mold 15. The core 16 is also formed of, for example, graphite similarly to the mold 15, has a length extending from the upper end to the lower end of the mold 15, and is provided with the lower end supported by a support portion 17 provided in the cooling chamber 11. ing.

The core 16 has a radially outwardly bulging side surface.
18a is approaching the inner surface of mold 15 and its upper surface 1
Four steps 18 are formed at equal intervals with the inclined portions 8b. The inclination angle of the upper surface 18b of the step portion 18 with respect to the horizontal plane is equal to or larger than the angle of repose (usually about 45 °) of the carbon powder C and the graphite powder B obtained by graphitizing the carbon powder C. B and C are configured to easily slide down without accumulating on the upper surface 18b of the step portion 18.

By disposing the core 16 at the axial position in the mold 15, an annular passage 19 having a horizontal cross section through which the carbon powder C and the graphite powder B can descend is formed in the mold 15. At the position of the step portion 18, a narrow portion 20 having a reduced width is formed.

Further, the above device is provided with gas blowing means for blowing the atmospheric gas into the passage 19. The gas blowing means includes two gas blowing pipes 21a and 21b incorporated in the core 16 and a gas blowing pipe 21 provided outside the furnace.
a, a gas supply source device (not shown) connected to 21b. Then, three gas blowing pipes 22 are radially connected to one of the gas blowing pipes 21a, as shown in FIG. 2, located below the uppermost step and the third step 18 from the top. The other gas blowing pipe 21b is similarly connected to a gas blowing pipe 22 located below the second step from the top and the lowermost stepped portion 18.
In addition, the gas supply source device includes the two gas injection pipes.
Gas is supplied alternately to 21a and 21b, and the gas blowing pressure can be changed in a pulsed manner at a predetermined cycle.

With the above configuration, this graphite powder manufacturing apparatus can manufacture graphite powder B by continuously graphitizing carbon powder C as a raw material.

That is, the carbon powder C as a raw material is previously filled in the passage 19, the cooling chamber 11, and the discharge hopper 12, and after the mold 15 is heated by the heater 5, the carbon powder is supplied to the charging hopper 7 through the supply pipe 8. A predetermined amount of carbon powder C is charged from the charging hopper 7 into the charging chamber 6 by pressing down the valve 9 at predetermined time intervals while continuously supplying C, and charged into the discharge hopper 12 by the screw feeder 14. Take out the powder that had been. As a result, the carbon powder C flows from the charging chamber 6 into the passage 19, and gradually descends by its own weight.

Then, the carbon powder C descending in such a manner is preheated by the mold 15 while passing through the preheating chamber 2, and is further heated to a temperature required for graphitization while passing through the heating chamber 3. It is heated and graphitized, where graphite powder B is produced.

The graphite powder B produced as described above is further cooled while gradually descending and passing through the pre-cooling chamber 4, flows down from the lower end of the mold 15 into the cooling chamber 11, and stays there for a predetermined time and is sufficiently cooled. After being forcibly cooled, it is discharged into the discharge hopper 12 through the discharge port 13 and the screw feeder 14
Are taken out by a predetermined amount.

In the graphitization process, the carbon powder C
From the heating chamber 3 to the cooling chamber 11 through the pre-cooling chamber 4 for about 3 hours from the time when the cooling chamber 11 flows into the mold 15 to the time when the cooling chamber 11 passes through the heating chamber 3 through the pre-heating chamber 2.
The descending speed of the powder (carbon powder C as a raw material and graphite powder B as a product) is preferably set so that the cooling time in the chamber 11 is about 10 hours. The charge amount of C and the amount of graphite powder B taken out from the discharge hopper 12 may be adjusted.

As described above, in this graphite powder production apparatus, the carbon powder C can be graphitized continuously and in a very short time as compared with the conventional batch type, and therefore, the production efficiency can be improved. Can be significantly improved.

In the above-described apparatus, the core 16 is provided in the mold 15 and the passage 19 through which the powder descends is formed in an annular shape, and the step 16 is provided in the core 16, so that when such a core 16 is not provided, It is possible to effectively prevent poor heat transfer to carbon powder C, its drift, and the occurrence of the shelf hanging phenomenon.

In other words, the thermal conductivity of the carbon powder C, which is a raw material, is not very good, and if the carbon powder C is simply lowered in the cylindrical mold 15, the powder in contact with the inner surface of the mold 15 is heated and the Although there is a possibility that the material that descends may not be sufficiently heated, in the apparatus of the above embodiment, the side surface of the step portion 18 formed in the core provided in the mold 15 is used.
When the mold 18a approaches the inner surface of the mold 15, sufficient heat is transferred from the mold 15 to the step 18 as shown in FIG. 3, and as a result, the temperature of the entire core 16 naturally increases. Therefore, the carbon powder C is heated not only from the outside by the mold 15 but also from the inside by the core 16, so that the carbon powder C
Can be surely graphitized.

Moreover, when the carbon powder C passes through the narrow portion 20 of the passage 19, the one flowing down along the surface of the core 16 as shown by the broken arrow in FIG. Along with flowing down along the outside, a part of the carbon powder C that has passed through the narrow portion 20 flows down toward the surface side of the core 16, so that the carbon powder C is naturally stirred in this portion, As a result, all of the carbon powders C can be uniformly heated to be surely graphitized.

Further, when the core 16 is not provided, the descent speed is large at the center of the mold 15, and at a portion along the inner surface of the mold 15, a sufficient descent speed due to frictional resistance generated between the core and the inner surface of the mold 15. It cannot be avoided, that is, as shown in FIG. 4 (b), it is inevitable that the descending speed becomes uneven at each position in the radial direction, and significant drift occurs. The descending speed is reduced, and as a result, as shown in FIG. 4 (b), the descending speed at each position can be made even closer to suppress the drift.

Further, when the core 16 is not provided,
There is a possibility that the falling powders mutually support each other to cause a so-called shelving phenomenon, so that the powder cannot be lowered. Particularly, in the lower portion of the mold 15, the weight of all the filled powders is heavy, so that it is easy for the shelves to be suspended. However, in the above apparatus, the core 16 having the step 18 is provided at the axial position in the mold 15, so that the powder is dispersed and supported by each step 18, and
There is no significant weight added to the lower part of 15, so that shelving is unlikely to occur.

Even if the hanging of the shelves occurs, in the above-described apparatus, the atmospheric gas is blown into the passage 19 by the gas blowing means, so that the hanging of the shelves can be easily eliminated by the gas pressure.

For example, as shown in FIG. 5 (a), when a shelf is suspended above the step 18 and a cavity 25 is formed, the cavity 25 is formed by the pressure of gas blown from below the step 18. The powder on the lower side is blown off, and the shelves are released by the pressure and impact, and as shown in FIG.
Even in the case where shelves are hung below the step portion 18 and the cavities 25 are formed, the powder on the upper side of the cavities 25 is crushed by the gas pressure, and the shelves are released.

When gas is simultaneously supplied to both the blowing pipes 21a and 21b and gas is simultaneously blown from all the gas blowing pipes 22, the gas pressure in the passage 19 only increases uniformly, and the difference between the upper and lower cavities 25 is increased. No pressure is generated, and therefore, it is difficult to break the shelving. However, by alternately supplying gas to the two systems of the blowing pipes 21a and 21b as described above, it is possible to apply pressure alternately from above and below the cavity 25. Can be easily eliminated. Moreover, by hanging the gas intermittently or by changing the gas pressure in a pulsed manner to increase or decrease the strength, the hanging on the shelf can be more effectively eliminated.

The blown gas is blown out from the upper and lower ends of the mold 15 through the gap of the powder, and
In the case where 15 is made of porous graphite, the air passes through the wall surface of the mold 15 and is exhausted to the outside.

The heater 5 provided in the heating chamber 3 is generally of a resistance heating type, but an induction heating type can also be employed. Also, the number of steps 18 provided in the core 16 and their intervals,
The shape and the like are not limited to the above-described embodiment, and may be changed as appropriate.

[Effects of the Invention] As described above in detail, the present invention is configured such that the mold penetrating the furnace body vertically is heated by the heating means, and the carbon powder flowing into the inside from the upper end of the mold is filled in the mold. The structure is designed to be graphitized by heating through a mold during the passage of the carbon powder, thus realizing continuous graphitization of the carbon powder, significantly improving productivity compared to the conventional batch-type graphitization. This has the effect of being able to be improved.

Then, by providing a core in the mold and making the passage where the powder descends into an annular horizontal cross section, the drift of the powder can be suppressed. Further, when a step is provided in the core, the weight of the powder is dispersed and supported by the step, thereby preventing the occurrence of the shelving phenomenon, and reducing the narrow portion of the passage formed by the step. When the powder passes, the powder is naturally stirred, and furthermore, heat is transferred from the mold to the core through the step portion, and the core is also heated, thereby graphitizing the carbon powder reliably and efficiently. The effect is that it can be done.

Further, if a gas blowing means for blowing gas into the passage is provided, there is an effect that the hanging of the shelf can be easily canceled by the gas pressure even if the hanging of the shelf occurs.

[Brief description of the drawings]

1 to 5 show an embodiment of a graphite powder producing apparatus according to the present invention. FIG. 1 is an elevational sectional view showing the overall schematic structure, and FIG. 2 is a line II-II in FIG. FIG. 3 is an enlarged view taken in the direction of an arrow, FIG. 3 is a partial vertical sectional view for explaining the heat transfer action from the mold to the step portion of the core, and the flow-down state of the powder in the narrow portion. FIG. Powder falling velocity distribution diagram,
FIG. 5B is a diagram showing, for comparison, the descent speed distribution in the case where there is no core, and FIG. 5 is a diagram for explaining the operation of the gas blowing means. FIG. 2B is a diagram illustrating a case where the shelf is suspended above the step, and FIG. 1 ... Furnace body, 2 ... Preheating room, 3 ... Heating room, 4 ... Precooling room, 5 ... Heater (heating means), 6 ... Loading room, 7 ... Loading hopper, 11 ... Cooling chamber, 12: Discharge hopper, 14: Screw feeder, 15: Mold, 16: Core, 18: Step, 18a: Side of step, 18b: Top of step, 19 ... Passages, 20: Narrow portions of passages, 21a, 21b: Gas blowing pipes (gas blowing means), 22: Gas blowing pipes, C: Carbon powder, B: Graphite powder.

Continued on the front page (72) Inventor Shin Shimizu 3-2-16-1 Toyosu, Koto-ku, Tokyo Inside Ishikawajima-Harima Heavy Industries, Ltd. Toyosu General Office (72) Inventor Osamu Takeuchi 3-1-1, Toyosu, Koto-ku, Tokyo (72) Inventor Akira Aizawa 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawa Shima-Harima Heavy Industries Co., Ltd. Tokyo Second Factory (56) References JP-A-2-2 14805 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C01B 31/04

Claims (3)

(57) [Claims] An apparatus for producing graphite powder, wherein graphite powder is graphitized by heating carbon powder to a high temperature, comprising: a furnace body; a cylindrical mold vertically penetrating the furnace body; Heating means for heating the mold from the outside, and the graphite powder is heated by the heating means through the mold while lowering the carbon powder charged into the mold from the upper end of the mold, whereby the mold is graphitized. A graphite core for removing the carbon powder from a lower end of the mold; and a cylindrical core for forming a passage having an annular horizontal cross section through which the carbon powder descends. 2. A graphite powder producing apparatus according to claim 1, wherein a narrow portion is formed in said passage by providing a stepped portion bulging radially outward in said core. . 3. The graphite powder production according to claim 2, further comprising gas blowing means for blowing gas into said passage through a gas blowing pipe provided inside said core. apparatus.