JPH08208210A - Production of graphite powder and production unit therefor - Google Patents

Abstract

PURPOSE: To provide a production method and production unit for graphite powder, designed to shorten heat treatment time through such processes that graphite balls are mixed with feedstock powder in a mixing tank provided between a feedstock tank and a feed pipe and the resultant mixture is charged into a heating vessel and conveyed from one end of the vessel to the other end followed by sieving to separate the graphite balls, which are then returned to the mixing tank. CONSTITUTION: A feedstock tank 11a is first charged with feedstock powder such as phenol and/or coke followed by closing a charge port 22 to close the tank 11a, which is then exhausted to remove the air and moisture in the feedstock followed by feeding an inert gas via a gas feed port 11e into the tank 11a. Secondly, a rotary valve 11b is opened and the feedstock powder is transferred to a mixing tank 13 and then mixed with graphite balls 12 in the mixing tank. Then, the resultant mixture is charged via a feed pipe 4 into one end inside a heating vessel 2 where the mixture is moved backward under agitation and mixing and heat-treated in a heating zone 10. The impurities in the feedstock is fed via an exhaust pipe 6 to an exhaust gas treating device 7. The resultant graphite powder, together with the graphite balls 12, reaches the other end of the heating vessel 2, and then housed, via a discharge pipe 5 and a sieve 14, in a product cooling tank 15a. The graphite balls 12 are returned through a net conveyer to the mixing tank 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphite powder production apparatus and a production method for producing graphite powder by heating and heat-treating resin, carbonaceous or graphite powder.

[0002]

2. Description of the Related Art Conventionally, as such a graphite powder manufacturing apparatus, there is one described in JP-A-3-183610, and this graphite powder manufacturing apparatus is made of graphite extending in the front-rear direction and is hollow. A cylindrical heating container is housed in a hollow furnace shell extending in the front-rear direction.

A supply pipe extending upward is provided at the front end of the heating container, and the upper end of the supply pipe is
It projects from the furnace shell and is connected to an external raw material tank.

A discharge pipe extending downward is provided at the rear end of the heating container, and the lower end of the discharge pipe is
It projects from the furnace shell and is connected to an external product tank.

Inside the heating container, the raw material powder charged from the raw material tank through the supply pipe into the heating container is
A screw feeder for transferring to the rear end is provided.

Further, a heater is provided around the heating container, the heater heats the heating container from the outside, and the raw material powder in the heating container is heat-treated at an appropriate temperature during the above transfer. By doing so, it is graphitized. The produced graphite powder is accommodated in the product tank from the inside of the heating container through the discharge pipe, and then cooled by the cooling device provided in the product tank.

The present invention intends to shorten the heat treatment time and, at the same time, reduce the cost required for the heat treatment by improving the heat transfer efficiency to the raw material powder in the above graphite powder manufacturing apparatus. is there.

[0008]

In order to solve the above problems, according to the present invention, a ball made of graphite is charged into a heating container together with the raw material powder through a supply pipe so that the raw material powder and the ball made of graphite are When the inside of the heating container is transferred from the end on the supply pipe side to the end on the discharge pipe side by gravity or a screw feeder, the raw material powder is heated in the heating container together with the graphite balls to produce graphite powder. When the produced graphite powder was discharged from the discharge tube together with the graphite balls, the graphite balls were separated, and the separated graphite balls were again charged into the heating container from the supply tube.

[0009]

In the graphite powder manufacturing apparatus according to the present invention,
Since the mixture of the raw material powder and the graphite balls in the heating container is heated in the heating container, heat is well transferred to the entire raw material powder through the graphite balls, and the raw material powder is effectively heat-treated and graphitized. be able to.

Further, the graphite balls heated in the heating container are discharged from the heating container and then mixed again with the raw material powder in a high temperature state by the returning means and charged into the heating container to obtain the raw material powder. Since it is used for heating, heat energy can be reused.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A graphite powder manufacturing apparatus according to the present invention will be described with reference to the accompanying drawings.

The graphite powder manufacturing apparatus 1 shown in FIG. 1 accommodates a graphite-made hollow cylindrical heating vessel 2 extending in the front-rear direction in a hollow furnace shell 3 extending in the front-rear direction. Heating container 2
Is inclined so that the front end is higher than the rear end in the furnace shell 3.

A supply pipe 4 extending upward is provided at the front end of the heating container 2, and the upper end of the supply pipe 4 projects from the furnace shell 3 to the outside.

A discharge pipe 5 extending downward is provided at the rear end portion of the heating container 2, and the lower end of the discharge pipe 5 projects from the furnace shell 3 to the outside.

A mixing tank 13 for adding and mixing the graphite balls 12 to the raw material powder is connected to the upper end of the supply pipe 4 via a rotary valve 13b. Further, the upper end portion of the mixing tank 13 is connected to the raw material tank 11a via a rotary valve 11b.

The graphite balls 12 are mixed with the raw material powder in the mixing tank 13, introduced into the heating container 2 through the supply pipe 4, and heated in the heating container 2 together with the raw material powder. The heat is well transferred to the entire raw material powder through the balls 12 of the above.

Therefore, the size of the graphite ball 12 is 10 to 500 times the maximum particle diameter of the raw material powder in consideration of heat conduction, easiness of mixing, processing amount, etc. It is desirable that the ratio be about 50% by volume.

Further, in order to efficiently heat the heating container 2, a system in which the heating container 2 itself is used as a heater is adopted as described below.

As shown in FIG. 1, the front and rear end portions of the heating container 2 are made thicker than the other portions of the heating container 2, and the lower ends of the thickened end portions are provided. Is provided with an electrode 9 whose upper end penetrates into the heating container 2 from the outside to reach the vicinity of the inner wall of the heating container 2, and whose lower end extends downward to project to the outside of the furnace shell 3.

An external power source (not shown) is provided between the electrodes 9.
When a voltage is applied to the heating container 2 and an electric current is passed through the heating container 2, the heating container 2 becomes a heater by the generated Joule heat, and the raw material powder and the graphite balls 12 are heated in the heating container 2 to heat-treat the raw material powder. You can

Further, the portion 10 between the front and rear ends of the heating container 2 has a smaller thickness than the both ends, so that the electric resistance is high and a large amount of Joule heat is generated to form a heating zone.

The temperature of the heating container 2 can be easily controlled by adjusting the voltage applied between both electrodes 9. The temperature of the heating zone 10 of the heating container 2 is 1800 to 30
00 ° C is desirable.

In the heating container 2, the balls 12 inside are
Since the material powder is inclined so as to roll from the front end to the rear end in the heating container 2, the raw material powder charged together with the balls 12 is agitated and moved backward as the balls 12 roll backward. When it is transferred and passes through the heating zone 10, it is heat treated to become graphite powder.

In this embodiment, no apparatus (feeder or the like) is required for transferring the raw material powder into the heating container 2, so that the cost of the member can be suppressed and the cost can be reduced.

An exhaust pipe 6 extending upward is provided at the upper part of the heating container 2 and from the front of the central part in the front-rear direction, and the upper end of the exhaust pipe 6 is outside the furnace shell 3 outside. And is connected to the exhaust gas treatment device 7. A high frequency coil 8 is provided around the exhaust pipe 6 in the furnace shell 3.

At the lower end of the discharge pipe 5, there is provided a sieving tank 14 for sieving the mixture of the graphite powder and the balls 12 discharged through the discharge pipe 5 and taking out only the balls 12. The sieving tank 14 is provided with a product cooling tank 15a at the bottom thereof, and the graphite powder that has been sieved and dropped downward is introduced into the product cooling tank 15a.

Between the sieving tank 14 and the mixing tank 13, the inside of the sieving tank 14 and the inside of the mixing tank 13 are communicated, and the balls 12 taken out by the sieving tank 14 are supplied to the mixing tank 13. A return pipe 17 is provided.

The return pipe 17 and the sieving tank 14 are internally provided with a series of net conveyors, and the balls 12 taken out by the sieving tank 14 are continuously returned to the mixing tank 13.

Therefore, even if the balls 12 heated in the heating container 2 to become hot are discharged from the heating container 2 through the discharge pipe 5, the balls 12 pass through the sieving tank 14 and the return pipe 17 and are mixed. Since the raw material powder is supplied to 13 and mixed with the raw material powder at a high temperature and used for heating the raw material powder in the heating container 2, the thermal energy can be reused.

In order to increase the heating efficiency of the heating container 2 and the utilization efficiency of heat energy by circulating the balls 12, the inner wall of each of the furnace shell 3, the discharge pipe 5, the sieving tank 14, the returning pipe 17 and the mixing tank 13 is increased. Is covered with a heat insulating material 18, so that the heat of the heating container 2 and the balls 12 does not easily escape to the outside.

Further, the furnace shell 3 is provided with a gas supply port 19a and a gas discharge port 19b in order to prevent the heat insulating material 18 and the like from being oxidized by the heat generated by the heating container 2, and by these, An inert gas is caused to flow in the space between the furnace shell 3 and the heating container 2 to remove the impurity gas that reacts with carbon and the impurity gas that causes insulation failure from the inside of the furnace shell 3.

At this time, if the pressure in the furnace shell 3 is made higher than the pressure in the heating container 2 by flowing an inert gas into the furnace shell 3, even if the heating container 2 is porous, Impurity gas generated in 2 does not leak out from the pores.

Further, the furnace shell 3 has a cooling water supply port 20a.
And a cooling water discharge port 20b are provided, and cooling water circulates between the furnace shell 3 and the heat insulating material 18 on the inner wall of the furnace shell 3 to suppress an increase in the surface temperature of the furnace shell 3. .

The lower end of the product cooling tank 15a is connected to the product take-out tank 16a via a rotary valve 15b. Further, at the lower end of the product take-out tank 16a, a product take-out port 21 is provided via a rotary valve 16b.
Is provided.

On the other hand, a raw material charging port 22 for charging the raw material powder into the raw material tank 11a is provided above the raw material tank 11a.

Raw material tank 11a and product take-out tank 16a
Is provided with gas supply ports 11c and 16c for supplying an inert gas to the insides of the tanks 11a and 16a, respectively, and a portion of the supply pipe 4 protruding from the furnace shell 3 and the product cooling tank 15a are provided. Is a gas supply port 2 for feeding an inert gas or a halogen gas into the heating container 2.
3, 15c are provided respectively.

When the halogen gas is supplied into the heating container 2, a halogen gas supply device (not shown) is connected to the gas supply ports 23 and 15c for the heating container 2 to supply both gas supply ports 23 and 15c. Halogen gas is always sent from the heating chamber 2 into the heating container 2, and the other gas supply ports 11c, 16
An inert gas supply device (not shown) is connected to c and 19a, and an inert gas is appropriately fed into the tanks 11a and 16a and the furnace shell 3 corresponding to the respective gas supply ports 11c, 16c and 19a.

As described above, when the inert gas and the halogen gas are used together, the rotary valves 11b and 15b at the lower ends of the raw material tank 11a and the product cooling tank 15a are hermetically sealed to a certain degree so that the two gases are not mixed. It is desirable to adopt a type that allows raw material powder and the like to flow downward while maintaining the property and a mechanism capable of gas replacement.

When supplying an inert gas into the heating container 2, an inert gas supply device (not shown) is provided at each gas supply port.
And the inert gas is constantly fed into each of the tanks 11a, 15a, 16a and the heating container 2.

As described above, each tank 11a, 15a,
Since gas is appropriately sent into the inside of 16a and the inside of the heating container 2, the impurity gas that reacts with carbon and the impurity gas that causes insulation failure are eliminated.

The product cooling tank 15a and the product take-out tank 16a are provided with a cooling device (not shown) for cooling the manufactured graphite powder.

Further, the raw material tank 11a is provided with a vacuum exhaust port 24, and this vacuum exhaust port 24 is connected to a vacuum exhaust device (not shown). The vacuum exhaust device can also be connected to the furnace shell gas discharge port 19b.

The operating method of the graphite powder manufacturing apparatus 1 will be described below.

Raw material inlet 2 at the upper end of the raw material tank 11a
From step 2, a predetermined amount of raw material powder such as phenol, coke or natural graphite is charged into the raw material tank 11a, the raw material inlet 22 is closed, and the raw material tank 11a is sealed.

Next, vacuum exhaust is performed through the vacuum exhaust port 24 to deaerate air and moisture from the raw material powder, and then an inert gas is supplied into the raw material tank 11a from the gas supply port 11c to supply the raw material tank 11a. The air inside is replaced with an inert gas.

Then, the rotary valve 11b at the lower end of the raw material tank 11a is opened, and the deaerated raw material powder is transferred into the mixing tank 13. When the rotary valve 11b is closed after the transfer of the raw material powder, air does not flow into the mixing tank 13 even if the raw material charging port 22 is opened. Therefore, the raw material powder is continuously charged into the raw material tank 11a, Can be degassed.

The raw material powder in the mixing tank 13 is mixed with the graphite balls 12 in the mixing tank 13, and then the mixing tank 13 is mixed.
By opening the rotary valve 13b between the supply pipe 4 and the supply pipe 4, the graphite balls 12 are introduced into the front end of the heating container 2 through the supply pipe 4.

The heating container 2 is kept at a predetermined temperature in advance by applying a voltage between the electrodes 9.

When the raw material powder and the balls 12 made of graphite are put into the heating container 2, if the rotary valve 13b is adjusted so as to be about half of the capacity of the heating container 2,
In the heating container 2, the above-mentioned gas flow path is secured so that the gas easily reaches the exhaust pipe 6, and the balls 12 roll rearward due to the inclination of the heating container 2 and the raw material by this rolling. Smooth movement of powder to the rear.

The raw material powder is agitated by the balls 12, moves backward, and is heat-treated when passing through the heating zone 10.

The time for performing this heat treatment can be adjusted by adjusting the inclination angle of the heating container 2 and the length of the heating zone 10.

The graphite balls 12 can enhance the heat conductivity to the raw material powder and generate heat when the balls 12 are energized to heat the raw material powder.

Impurities in the raw material powder that are vaporized during the heat treatment are released from the raw material powder and mixed with the gas in the heating container 2 to move through the exhaust pipe 6 to the exhaust gas treatment device 7
Since it reaches and is processed, impurities do not adhere to the graphite powder, and high-purity graphite powder is manufactured.

At this time, the high-frequency coil 8 heats the exhaust pipe 6 by induction heat generation so that the vaporized impurities are less likely to adhere to the inside of the exhaust pipe 6.

Further, since the exhaust pipe 13 is located near the front of the heating container 2, even if impurities adhere to the inside of the exhaust pipe 6 and then fall, the dropped impurities will be contained in the heating zone 10. Since it adheres to the raw material powder in the front, is heated again in the heating zone 10 and is vaporized and released from the raw material powder, the purity of the graphite powder does not decrease.

The graphite powder produced moves backward as the balls 12 roll backward, reaches the rear end of the heating container 2, passes through the discharge pipe 5, and is sieved together with the balls 12. It is put into the dividing tank 14.

The charged mixture of the balls 12 and the graphite powder is sieved by a net conveyor in the sieving tank 14, the balls 12 are taken out, the graphite powder falls downward, and the lower portion of the sieving tank 14 Product cooling tank 15
It is stored in a.

The balls 12 taken out are used in the sieving tank 1
4, a series of net conveyors provided in the return pipe 17 moves in the sieving tank 14 and the return pipe 17, and is heated and charged into the mixing tank 13 to heat the raw material powder. Will be used again.

Since the graphite powder that has flowed into the product cooling tank 15a is extremely hot, it preheats the inert gas or halogen gas from the gas supply port 15c and is cooled by the cooling device provided in the product cooling tank 15a. It

Thereafter, the graphite powder in the product cooling tank 15a is transferred to the product take-out tank 16a by opening the rotary valve 15b at the lower end of the tank 15a.

The graphite powder transferred into the product take-out tank 16a is cooled again by the cooling device provided in the product take-out tank 16a, and then the rotary valve 16b at the lower end of the product take-out tank 16a is opened. , The product take-out port 21.

At this time, if the rotary valve 15b at the lower end of the product take-out tank 15a is closed, the product take-out tank 1
Even if air flows into the product take-out tank 16a from the product take-out port 21 when the rotary valve 16c at the lower end of 6a is opened, it does not reach the heating container 2, so that the graphite powder manufacturing apparatus 1 is operating. Also, the graphite powder in the product take-out tank 16a can be taken out from the product take-out port 21.

The graphite powder manufacturing apparatus 31 shown in FIG.
The heating container 2 is provided with a screw feeder 32. The rotation shaft of the screw feeder 32 has a rear end extending rearward from the rear end in the heating container 2 and protruding to the outside of the furnace shell 3 to provide an external screw. Feeder drive device 3
Connected to 3.

The graphite powder manufacturing apparatus 31 forcibly transfers the raw material powder in the heating container 2 and the graphite balls 12 from the front end to the rear end, so that the front end of the heating container 2 is higher than the rear end. It is not necessary to incline, and the heating time can be variously changed by adjusting the rotation speed of the screw feeder 32.

[0065]

[Effect] With the graphite powder manufacturing apparatus according to the present invention configured as described above, the graphite balls agitate the raw material powder in the heating container, and heat is applied to the entire raw material powder through the balls. Thus, the raw material powder is effectively heat-treated, so that the heat treatment time can be shortened.

Further, the graphite balls heated and heated in the heating container are discharged from the heating container, mixed again with the raw material powder in a high temperature state, and charged into the heating container. It can be reused, the electric power required for the heat treatment of the raw material powder can be suppressed, and the running cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of a graphite powder manufacturing apparatus according to the present invention.

FIG. 2 is a vertical sectional view of a second embodiment of the graphite powder manufacturing apparatus according to the present invention.

[Explanation of symbols]

 1, 31 Graphite powder manufacturing device 2 Graphite heating container 3 Furnace shell 4 Supply pipe 5 Exhaust pipe 6 Exhaust pipe 7 Exhaust gas treatment device 8 High frequency coil 9 Electrode 10 Heating zone 11a Raw material tank 12 Graphite ball 13 Mixing tank 14 Sieve Tank 15a Product cooling tank 16a Product take-out tank 11b, 13b, 15b, 16b Rotary valve 11c, 15c, 16c Tank gas supply port 17 Return pipe 18 Insulation material 19a Furnace shell gas supply port 19b Furnace shell gas discharge port 20a Cooling Water supply port 20b Cooling water discharge port 21 Product outlet 22 Raw material input port 23 Heating container gas supply port 32 Screw feeder 33 Screw feeder drive device

Claims (4)

[Claims] 1. A graphite hollow cylindrical heating container having a supply pipe at one end and a discharge pipe at the other end is housed in a hollow furnace shell, and the supply pipe and the discharge pipe are drawn out of the furnace shell. A raw material tank is provided at the end of the supply pipe outside the furnace shell, and a product tank is provided at the end of the discharge pipe outside the furnace shell.The raw material powder fed from the raw material tank through the supply pipe into the heating container is heated. In a graphite powder manufacturing device that heat-treats in a container to graphitize and stores this graphitized powder in a product tank through a discharge pipe, a graphite ball is added to and mixed with the raw material powder between the raw material tank and the supply pipe. The heating container is provided with an inclination angle at which the balls thrown into the heating container roll from the end on the supply pipe side toward the end on the discharge pipe side, and the balls are placed in front of the product tank. A sieving means for separation was provided, and separation was performed by the sieving means. An apparatus for producing graphite powder, which is provided with a returning means for returning the balls to the mixing means. 2. A graphite hollow cylindrical heating vessel having a supply pipe at one end and a discharge pipe at the other end is housed in a hollow furnace shell, and the supply pipe and the discharge pipe are provided outside the furnace shell. A raw material tank is provided at the end of the supply pipe outside the furnace shell, a product tank is provided at the end of the discharge pipe outside the furnace shell, and the raw material powder charged from the raw material tank through the supply pipe into the heating container is heated. A screw feeder that transfers from one end to the other inside the container is provided, and at the time of transferring this raw material powder, the raw material powder is heat treated in a heating container to be graphitized, and this graphitized powder is stored in the product tank through a discharge pipe. In the graphite powder manufacturing apparatus, the mixing means for adding and mixing the balls made of graphite to the raw material powder is provided between the raw material tank and the supply pipe, and the sieving means for separating the balls is provided in front of the product tank. Hands mixing balls separated by An apparatus for producing graphite powder, which is provided with a returning means for returning to a stage. 3. A power supply means is connected to the heating container,
On the upper part of the heating container, an exhaust pipe is provided which has one end protruding outside the furnace shell and connects the inside of the heating container with the outside of the furnace shell, and an exhaust gas treatment device is connected to one end of this exhaust pipe to connect it to the heating container. The graphite powder production apparatus according to claim 1 or 2, further comprising an inert gas or halogen gas supply means connected thereto. 4. A graphite-made hollow cylindrical heating vessel having a supply pipe at one end and a discharge pipe at the other end is housed in a hollow furnace shell, and the supply pipe and the discharge pipe are placed outside the furnace shell. Withdrawing, the raw material tank is provided at the end outside the furnace shell of the supply pipe, the product tank is provided at the end outside the furnace shell of the discharge pipe, and the raw material powder charged into the heating container from the raw material tank through the supply pipe, In a graphite powder manufacturing method in which heat treatment is performed in a heating container to graphitize, and then the graphitized powder is stored in a product tank through a discharge pipe, a graphite ball is added to the raw material powder between the raw material tank and the supply pipe. Providing a mixing means for mixing, throwing balls into the heating container, transferring the balls together with the raw material powder from one end to the other end in the heating container, and a sieving means for separating the balls in front of the product tank. Provided to discharge graphite powder and balls from the heating container A method for producing graphite powder, characterized in that after the ball is separated, the ball is separated, a return means for returning the ball to the mixing means is provided, and the ball is introduced into the mixing means after the separation.