KR20210079544A - Continuous graphitization apparatus using induction heating furnace - Google Patents

Abstract

A continuous graphitization apparatus is disclosed. The continuous graphitization apparatus according to an exemplary embodiment of the disclosed present invention includes: i) a crucible transfer unit transferring crucibles charged with graphitized materials along a set transfer path; ii) an induction heating unit induction heating the crucibles transferred through the crucible transfer unit in at least one induction heating chamber, and graphitizing the graphitized materials; iii) a cooling unit cooling the crucibles discharged from the induction heating unit to a temperature set in a cooling chamber.

Description

Continuous graphitization apparatus using induction heating {CONTINUOUS GRAPHITIZATION APPARATUS USING INDUCTION HEATING FURNACE}

An embodiment of the present invention relates to a graphitizing apparatus, and more particularly, to a graphitizing apparatus for graphitizing a graphitizing material such as coke powder by heating.

In general, graphite-based carbon materials used as anode materials for lithium-ion batteries include natural graphite that is generated and mined in nature, and artificial graphite manufactured by heat-treating coal-based and petroleum-based pitch.

Artificial graphite, which has advantages in lifespan and rapid charging compared to natural graphite, requires optimization of graphitization to increase capacity to the level of natural graphite and lower manufacturing cost.

Artificial graphite graphitization mainly uses an acheson furnace. This process puts coke in a graphite crucible and covers packing coke, and then proceeds in the order of energization, blackout, cooling, exit, and crucible discharge. It is taking time.

Accordingly, conventionally, by continuously graphitizing a graphitizing material such as coke, processes for manufacturing artificial graphite more efficiently have been attempted.

Matters described in this background section are prepared to enhance understanding of the background of the invention, and may include matters that are not already known to those of ordinary skill in the art to which this technology belongs.

Embodiments of the present invention are to provide a continuous graphitization apparatus capable of graphitizing the graphitization material charged in a crucible by induction heating in a continuous process.

The continuous graphitization apparatus according to an embodiment of the present invention comprises: i) a crucible transport unit for transporting crucibles charged with graphitized material along a set transport path, and ii) at least the crucible transported through the crucible transport unit. An induction heating unit for induction heating in one induction heating chamber and graphitizing the graphitized material, and iii) a cooling unit for cooling the crucible discharged from the induction heating unit to a temperature set in the cooling chamber. .

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber may be provided to be interconnected as a plurality through a partition wall between the crucible transfer unit and the cooling unit.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber includes a first opening/closing opening formed on the transport path side, a second opening/closing opening formed on the partition wall, and the cooling chamber side. It may include a third opening and closing opening formed.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber may include an opening and closing member for opening and closing the first, second, and third openings, respectively.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber may include a gas injection unit for injecting an inert gas and a reactive gas into the inner space.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating unit is fixedly installed on the inner bottom surface of the induction heating chamber, and a fixed insulation module supporting the crucible; It may include a movable heat insulation module installed to be movable in the vertical direction with respect to the module, and an induction heating coil part installed to be connected to the movable heat insulation module and surrounding the crucible on the fixed heat insulation module inside.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber is installed in the inner space, and may include a gripper module for loading and unloading the crucible with respect to the fixed thermal insulation module. .

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating unit is the same material as the crucible, and is installed to penetrate the movable insulation module in the vertical direction, and when the movable insulation module is lowered It may further include a temperature measuring tool having a lower end positioned at the upper end of the crucible.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the temperature measuring tool is made of a graphite material, and may be provided in a cylindrical shape with an open upper end and a closed lower end.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber is installed at the upper end, and may further include a transparent window made of a quartz material exposing the lower end of the temperature measuring device to the outside. .

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the induction heating chamber detects energy radiated from the lower end of the temperature measuring tool through the transparent window to measure the heating temperature of the crucible. It may further include a rommeter.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the cooling chamber has an inlet for introducing the crucible discharged from the induction heating unit into an internal space, and an outlet for discharging the crucible to the outside. and a cooling medium injection unit for injecting the cooling medium into the inner space.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the cooling chamber may further include an opening/closing member for selectively opening and closing the inlet and the outlet.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the cooling unit may include a conveyor disposed between the inlet and the outlet in the inner space of the cooling chamber.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, the crucible is made of a graphite material, and may be provided with a thickness satisfying 0.1 to 4.0 times the current penetration depth.

In addition, in the continuous graphitization apparatus according to an embodiment of the present invention, a plurality of sub crucibles may be disposed inside the crucible.

Since the embodiments of the present invention can graphitize the graphitized material by induction heating and graphitization in a continuous process, the facility utilization rate and operational productivity can be improved, and the investment cost can be reduced by reducing the heating equipment of the graphitized material.

In addition, the effects obtainable or predicted by the embodiments of the present invention are to be disclosed directly or implicitly in the detailed description of the embodiments of the present invention. That is, various effects predicted according to an embodiment of the present invention will be disclosed in the detailed description to be described later.

Since these drawings are for reference in describing an exemplary embodiment of the present invention, the technical spirit of the present invention should not be construed as being limited to the accompanying drawings.
1 is a view schematically showing a continuous graphitization apparatus according to an embodiment of the present invention.
2 is a view showing a portion of a temperature measuring tool applied to the continuous graphitization apparatus according to an embodiment of the present invention.
3 is a view showing another example of a crucible applied to the continuous graphitization apparatus according to an embodiment of the present invention.
4 to 8 are views for explaining the effect of the continuous graphitization apparatus according to embodiments of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts irrelevant to the description are omitted, and the same reference numerals are given to the same or similar elements throughout the specification.

Since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the bar shown in the drawings, and the thickness is enlarged to clearly express various parts and regions.

In addition, in the following detailed description, the reason for dividing the names of components into first, second, etc. is to distinguish them due to the same relationship, and it is not necessarily limited to the order in the following description.

Throughout the specification, when a part includes a certain element, it means that other elements may be further included, rather than excluding other elements, unless otherwise stated.

In addition, terms such as ... unit, ... means, ... part, ... member described in the specification mean a unit of a comprehensive configuration that performs at least one function or operation.

1 is a view schematically showing a continuous graphitization apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , the continuous graphitization apparatus 100 according to an embodiment of the present invention may be applied to a process of manufacturing artificial graphite by heat-treating coal-based and petroleum-based pitch as a graphitizing material.

For example, the graphitization material may include coke powder. Artificial graphite prepared by graphitizing such a graphitized material can be used as an anode material for a lithium ion battery.

Hereinafter, based on the mounting positions of the components, the upper portion is defined as the upper portion, the upper portion, the upper surface, and the upper portion, and the lower portion is defined as the lower portion, the lower portion, the lower surface and the lower portion.

Furthermore, an end (one/one end or the other/one end) in the following may be defined as either end, and a certain part (one/one end or the other/one end) including the end. may be defined.

The continuous graphitization apparatus 100 according to an embodiment of the present invention has a structure capable of graphitizing the graphitized material charged in the crucible 1 (also referred to as a tray in the industry) by induction heating in a continuous process.

To this end, the continuous graphitization apparatus 100 according to an embodiment of the present invention basically includes a crucible transfer unit 10, an induction heating unit 20, and a cooling unit 70, which will be described for each configuration. If you do:

The components as described above are configured in the base frame 3 , the base frame 3 is disposed along the process direction on the floor of the process workshop, and may be provided as one frame or two or more frames connected to each other.

Furthermore, the base frame 3 may include various accessory elements such as brackets, bars, rods, plates, blocks, collars, etc. for mounting the components.

However, since the above-described accessory elements are for installing each component to be further described below on the base frame 3, in the embodiment of the present invention, except for exceptional cases, the aforementioned accessory elements are installed on the base frame 3 referred to as

In an embodiment of the present invention, the crucible transport unit 10 is for transporting the crucibles 1 loaded with the graphitized material in the process direction along a set transport path.

Here, the crucible 1 is made of a graphite material, and is provided in a cylindrical shape with an open upper end and a closed lower end.

The crucible transfer unit 10 includes a first conveyor 11 installed on the base frame (3). The first conveyor 11 is a known art conveyor device, which supports the crucibles 1 and is provided to be traversable along a process direction on a crucible.

In an embodiment of the present invention, the induction heating unit 20 inductively heats at least one crucible 1 transferred through the crucible transfer unit 10 to a temperature set in the induction heating chambers 21 and 22, and graphite It is for graphitizing the graphitization material.

Here, induction heating uses the principle of electromagnetic induction in which a current flows in a closed circuit by a magnetic field that changes with time. Such induction heating is a phenomenon in which when an alternating current flows by arranging a coil around a heating object such as a conductor, heat is generated and heated in the heating object by eddy current loss and hysteresis loss.

In an embodiment of the present invention, the induction heating is performed by placing an induction heating coil on the outside of the crucible (1) in which the graphitized material is charged, and flowing a current to the induction heating coil to inductively heat the graphitized material in the crucible (1). will be.

The induction heating chambers 21 and 22 are installed on the base frame 3 . The induction heating chambers 21 and 22 form an induction heating space 23 therein. The induction heating chambers 21 and 22 are disposed between the crucible transfer unit 10 and the cooling unit 70 .

The induction heating chambers 21 and 22 are provided to be interconnected as a plurality through the partition wall 25 in the embodiment of the present invention. The plurality of induction heating chambers 21 and 22 form an induction heating space 23 partitioned independently from each other along a process direction.

The induction heating chambers 21 and 22 form two regions of the induction heating space 23 through the partition wall 25 as shown in the drawing, but are not necessarily limited thereto, and depending on the manufacturing capacity of the artificial graphite Various numbers may be provided through the partition walls 25 .

Hereinafter, the induction heating chamber 21 located on the crucible transfer unit 10 side is referred to as a first induction heating chamber 21 for convenience, and the induction heating chamber 22 located on the cooling unit 70 side is a second It is called induction heating chamber 21 .

In an embodiment of the present invention, the first induction heating chamber 21 forms a first opening 31 on the side of the first conveyor 11 of the crucible transfer unit 10 , and the second opening and closing opening on the partition wall 25 . Forming (32), the second induction heating chamber (22) forms a third opening (33) on the cooling unit (70) side.

The first opening and closing opening 31 interconnects the transfer path side of the crucible transfer unit 10 and the induction heating space 23 of the first induction heating chamber 21 . The second opening 32 interconnects the induction heating space 23 of the first and second induction heating chambers 21 and 22 . In addition, the third opening 33 interconnects the cooling unit 70 side and the induction heating space 23 of the second induction heating chamber 22 . The first, second, and third openings 31, 32, and 33 are located on the same line along the process direction.

Furthermore, a first opening/closing member 35 for opening and closing the first, second, and third openings 31, 32 and 33, respectively, is installed in the first and second induction heating chambers 21 and 22 . The first opening/closing member 35 may move in the vertical direction, and may open and close the first, second, and third openings 31, 32, and 33, respectively. The first opening/closing member 35 may be reciprocally moved in the vertical direction by a known technology driving unit such as a hydraulic cylinder.

Further, the first and second induction heating chambers 21 and 22 include a gas injection unit 37 for injecting an inert gas and a reactive gas for induction heating into the induction heating space 23 .

Here, the inert (inert) gas may include nitrogen gas and argon gas, and the reactive gas may include a very small amount of hydrogen and a very small amount of oxygen. In an embodiment of the present invention, any one of nitrogen gas and argon gas is injected into the induction heating space 23 of the first and second induction heating chambers 21 and 22 through the gas injection unit 37 , respectively. can be

In addition, in the embodiment of the present invention, nitrogen gas and argon gas may be respectively injected into the induction heating space 23 of the first and second induction heating chambers 21 and 22 through the gas injection unit 37 . .

On the other hand, in the induction heating unit 20 according to an embodiment of the present invention, a coil is disposed around the crucible 1 introduced into the first and second induction heating chambers 21 and 22, and an alternating current flows through the coil. By doing so, the crucible 1 of the object to be heated can be heated with heat due to eddy current loss and hysteresis loss.

In an embodiment of the present invention, the induction heating unit 20 includes a fixed thermal insulation module 41, a movable thermal insulation module 43 and an induction heating coil unit configured in the first and second induction heating chambers 21 and 22, respectively. (45) is included.

In the induction heating space 23 of each induction heating chamber 21, 22 of the fixed thermal insulation module 41 is fixedly installed on the inner floor surface. The fixed thermal insulation module 41 is provided in the form of a block made of a thermal insulation material (eg, ceramic or porous graphite, etc.), and supports the crucible 1 through the upper surface.

The movable thermal insulation module 43 is installed to be movable in the vertical direction in the fixed thermal insulation module 41 in the induction heating space 23 . The movable thermal insulation module 43 is provided in the form of a block made of a thermal insulation material (eg, ceramic or porous graphite, etc.).

Here, the movable thermal insulation module 43 may be installed to be reciprocally movable in the vertical direction by the driving unit 47 provided in the induction heating space 23 . For example, the driving unit 47 may include a hydraulic cylinder of a known art, and may include a moving device of a known art for reciprocating a movable body in the vertical direction through a guide mechanism as driving a servo motor.

In addition, the induction heating coil part 45 can wrap the crucible 1 on the fixed thermal insulation module 41 inside when the movable thermal insulation module 43 is lowered, and the lower end of the movable thermal insulation module 43 . installed to be connected to

When an alternating current of a set frequency is supplied to the induction heating coil unit 45, a magnetic field is formed around the induction heating coil unit 45 in an embodiment of the present invention, and the crucible 1 and/or by electromagnetic induction. Heat due to eddy current loss and hysteresis loss is generated in the graphitized material in the crucible 1 , and heat treatment of the graphitized material may be performed by such induction heating.

The induction heating coil unit 45 is, for example, a multi-wound coil, and may have a circular, oval or rectangular winding shape, and the crucible 1 as described above is movable on the fixed thermal insulation module 41 . It may be located inside the induction heating coil unit 45 by the lowering of the module 43 .

In this case, as an alternating current flows in the induction heating coil part 45, a current flow occurs in the crucible 1 by electromagnetic induction, and also current flows in the graphitized material inside the crucible 1 This can happen.

Since the frequency of the alternating current flowing to the induction heating coil unit 45 may be set in various ways according to induction heating conditions, the embodiment of the present invention is not limited to any specific numerical range.

Here, the thickness of the crucible 1 according to the embodiment of the present invention may satisfy 0.1 to 4.0 times the current penetration depth δ defined by the following equation.

은 도가니의 비투자율,

는 진공 투자율(4π x 10^-7H/m)이다.In the above formula, ρ is the resistivity (Ω om) of the crucible, f is the frequency (Hz) of the induction heating current,

The relative permeability of the silver crucible,

is the vacuum permeability (4π x 10 ^-7 H/m).

If the thickness of the crucible 1 does not satisfy the above conditions, and is thicker than the condition, the current flow between the crucible 1 and the graphitized material by the induction heating coil unit 45 is not smooth, and more than the above conditions If it is thin, induction heating of the crucible 1 and/or the graphitized material may not be performed efficiently by affecting the magnetic flux by the induction heating coil unit 45 .

Furthermore, based on the set size of the crucible, when the induction heating frequency is varied, if the induction heating frequency is too high, the current penetration depth becomes small, so only the outer surface part of the graphitized material is heated, so that the heat emission to the outside is reduced. In contrast, if the current penetration depth is deep, that is, if the induction heating frequency is too low, energy penetrates to the center of the graphitized material and the magnetic flux cancels each other out, thereby reducing the efficiency. Accordingly, the selection of an appropriate induction heating frequency should be selected in consideration of the pattern of heat radiating from the graphitized material to the outside and the factor of offsetting the magnetic field lines in the central region.

In addition, when the induction heating frequency has already been set, if the size of the crucible is too small, the magnetic flux is canceled. Conversely, if the size of the crucible is too large, only the outer surface portion is heated.

And, when the thickness of the crucible is too thin, resistance heating occurs on the side of the crucible by the induced current by the coil in the induction heating method. There is a limit to how short the time it can endure.

Therefore, the thickness of the crucible can be set by comprehensively considering the offset of magnetic flux, an appropriate temperature gradient so that only the surface of the crucible is not heated, and the limited use time of the crucible.

Since the thickness of the crucible 1 may vary depending on the size of the crucible 1, the type and amount of graphitized material, the frequency of an alternating current, etc., it is not limited to any specific numerical value in the embodiment of the present invention.

Meanwhile, the gripper module 39 installed in the induction heating space 23 is installed in the first and second induction heating chambers 21 and 22 as described above. The gripper module 39 grips the crucible 1 , and is for loading and unloading the crucible 1 with respect to the fixed thermal insulation module 41 .

The gripper module 39 is a hydraulic cylinder actuated by hydraulic pressure, which is finger-operated, and includes a known art finger means (not shown) for gripping the crucible 1, and a multi-axial movement of the finger means for gripping the crucible 1 . It may include a multi-axis moving means (not shown in the drawings) of the known art for For example, the multi-axis moving means may reciprocate the movable body in a multi-axis direction by driving a working cylinder and a servo motor.

Here, the gripper module 39 opens the first opening 31 through the first opening and closing member 35 in the induction heating space 23 of the first induction heating chamber 21, and the crucible transfer unit Gripping the crucible (1) transferred by (10), moving the crucible (1) to the induction heating space (23) of the first induction heating chamber (21), and loading on the fixed thermal insulation module (41) can do.

In addition, the gripper module 39 opens the second opening 32 through the first opening and closing member 35 in the induction heating space 23 of the second induction heating chamber 22, Grip the crucible (1) located on the fixed thermal insulation module (41) in the heating chamber (21), and move the crucible (1) to the induction heating space (23) of the second induction heating chamber (22), It can be loaded onto the fixed thermal insulation module 41 .

In addition, the gripper module 39 opens the third opening/closing opening 33 through the first opening/closing member 35 in the induction heating space 23 of the second induction heating chamber 22, allowing the second induction The crucible 1 positioned on the fixed thermal insulation module 41 in the heating chamber 22 may be gripped, and the crucible 1 may be moved to the cooling unit 70 side.

On the other hand, the induction heating unit 20 according to an embodiment of the present invention includes a temperature measuring tool 51 and a pyrometer (51) for stably and reliably measuring the heating temperature of the crucible (1) and/or graphitized material. 61) is further included.

The temperature measuring tool 51 is the same material (graphite material) as the crucible 1, and is installed to penetrate the movable insulation module 43 in the vertical direction. The lower end of the temperature measuring tool 51 is located at the top of the crucible 1 supported on the fixed thermal insulation module 41 when the movable thermal insulation module 43 is lowered.

As shown in FIG. 2, the temperature measuring tool 51 is provided in a cylindrical shape with an open upper end and a closed lower end. At the upper end of the temperature measuring tool 51 , a flange extending from the upper end to the outside of the edge is formed, and the upper surface of the movable thermal insulation module 43 can be supported through the flange.

Here, the lower end of the temperature measuring tool 51 protrudes to the lower end of the movable thermal insulation module 43 , passes through the closing plate 53 attached to the lower end of the movable thermal insulation module 43 and the closing plate 53 . is fixed on The above-mentioned closing plate 53 has a function of closing the upper end of the crucible 1 supported on the fixed thermal insulation module 41 and protecting the lower end of the movable thermal insulation module 43 when the movable thermal insulation module 43 is lowered. will function.

A quartz material for exposing the lower end to the outside through the upper end (open end) of the temperature measuring instrument 51 at the upper end of the first and second induction heating chambers 21 and 22 corresponding to the temperature measuring tool 51 as described above of the transparent window 55 is installed.

In addition, the pyrometer 61 is fixedly installed on the outer upper ends of the first and second induction heating chambers 21 and 22 to correspond to the transparent window 55 .

The pyrometer 61 senses the energy radiated from the lower end of the temperature measuring tool 51 through the transparent window 55 and converts it into an electric signal, and processes the electric signal to the crucible 1 and/or graphite It is equipped with a pyrometer to measure the heating temperature of the material.

The pyrometer 61 is a non-contact high-temperature instrument that measures the surface temperature of the heating object by the intensity of radiant energy emitted from the surface according to the temperature of the heating object.

Specifically, when radiation energy is generated from a heating object, the pyrometer 61 collects energy radiated through an optical system. Accordingly, the detector converts the collected radiant energy into an electric signal, and the internal circuit undergoes an ambient temperature compensation circuit and emissivity adjustment process. The emissivity adjustment adjusts the emissivity to match the radiation characteristics of the heating object and the thermometer scale. is to adjust

Here, when the graphitized material undergoes a graphitization process and the physical properties are changed, the emissivity may be changed, and since energy radiated from the optical system is collected, the flatness of the heating object is important. Accordingly, by inserting the temperature measuring tool 51 with a flat lower end in a state where the emissivity is set, the stability of the emissivity and the flatness of the temperature measurement point are secured, thereby increasing the reliability of temperature measurement.

Since the configuration of the pyrometer 61 is configured of a pyro-radiation pyrometer or an optical thermometer of a well-known technique in the art, a more detailed description of the configuration will be omitted herein.

Finally, in an embodiment of the present invention, the cooling unit 70 is configured to cool the crucible 1 discharged from the first and second induction heating chambers 21 and 22 to a temperature set in the cooling chamber 71 . will be.

In the above, the cooling chamber 71 is installed on the base frame 3 . The cooling chamber 71 includes an inlet 73 for introducing the crucible 1 discharged from the first and second induction heating chambers 21 and 22 into the internal space, and an inlet 73 for discharging the crucible 1 to the outside. An outlet 75 for the purpose and a cooling medium injection unit 77 for injecting the cooling medium into the inner space are formed.

A second opening/closing member 79 for opening and closing the inlet 73 and the outlet 75, respectively, is installed in the cooling chamber 71 . The second opening/closing member 79 moves in the vertical direction, and may open and close the inlet 73 and the outlet 75, respectively. The second opening/closing member 79 may be reciprocally moved in the vertical direction by a known technology driving unit such as a hydraulic cylinder.

In the above, the cooling medium injection unit 77 may inject nitrogen gas or argon gas as a cooling medium into the inner space of the cooling chamber 71 .

Furthermore, the cooling unit 70 further includes a second conveyor 81 installed on the inner bottom side of the cooling chamber 71 . The second conveyor 81 is disposed between the inlet 73 and the outlet 75 in the inner space of the cooling chamber 71 .

The second conveyor 81 is a known art conveyor device, which supports the crucibles 1 in the inner space of the cooling chamber 71 and is provided to be traversable along the process direction on a caterpillar. The second conveyor 81 may transport the crucible 1 discharged from the first and second induction heating chambers 21 and 22 from the inlet 73 side to the outlet 75 side along the process direction.

Hereinafter, the operation and effect of the continuous graphitization apparatus 100 according to an embodiment of the present invention configured as described above will be described in detail with reference to the previously disclosed drawings and the accompanying drawings.

First, in the embodiment of the present invention, the crucibles 1 charged with graphitization material such as coke powder are first and second induction heated along a transport path set through the first conveyor 11 of the crucible transport unit 10 . It is transferred to the chamber (21, 22) side.

Here, the first, second, and third openings 31 , 32 , and 33 of the first and second induction heating chambers 21 and 22 are in an open state by the first opening and closing member 35 . In addition, in the first and second induction heating chambers 21 and 22 , the movable thermal insulation module 43 of the induction heating unit 20 puts the fixed thermal insulation module 41 on the lower side and the upper side by the driving of the driving unit 47 . moved in the direction.

In this state, in the embodiment of the present invention, the crucible 1 transferred by the crucible transfer unit 10 is gripped through the gripper module 39, and the induction heating space of the first induction heating chamber 21 ( 23) in the fixed thermal insulation module 41 is loaded.

And, in the embodiment of the present invention, the crucible 1 loaded on the fixed thermal insulation module 41 in the induction heating space 23 of the first induction heating chamber 21 is gripped through the gripper module 39 . and loaded on the fixed thermal insulation module 41 in the induction heating space 23 of the second induction heating chamber 22 .

In addition, in the embodiment of the present invention, the other crucible 1 transferred by the crucible transfer unit 10 is gripped through the gripper module 39, and the induction heating space 23 of the first induction heating chamber 21 is ) is loaded on the fixed thermal insulation module 41 in.

Next, in an embodiment of the present invention, all of the first, second, and third openings 31, 32 and 33 of the first and second induction heating chambers 21 and 22 are closed through the first opening and closing member 35 do.

Then, in the embodiment of the present invention, the movable thermal insulation module 43 is moved downward by the driving of the driving unit 47 . Accordingly, the induction heating coil part 45 of the induction heating unit 20 wraps the outer surface side of the crucible 1 with the crucible 1 on the fixed thermal insulation module 41 inside.

In this case, the lower end of the temperature measuring tool 51 is positioned at the upper end of the crucible 1 through the movable heat insulating module 43, and the closing plate 53 at the lower end of the movable heat insulating module 43 is the temperature measuring tool ( 51) to close the upper end of the crucible (1) while supporting the lower end.

Thereafter, in the embodiment of the present invention, nitrogen gas and argon gas as inert gases are introduced through the gas injection unit 37 to the induction heating space 23 of the first and second induction heating chambers 21 and 22 . Each is injected into the heating space (23).

That is, in the embodiment of the present invention, nitrogen gas is supplied to the induction heating space 23 of any one of the first and second induction heating chambers 21 and 22 and argon gas is supplied to the other induction heating space 23 . It may be injected through the gas injection unit 37 .

To explain further, depending on the atmospheric gas, even at the same temperature, the graphitization degree of the graphitization material may be affected differently, and the type of graphitization material may also affect the graphitization degree depending on the atmospheric gas. Different inert gases may be separately injected into the first and second induction heating chambers 21 and 22 in order to input the graphitization material or to control different graphitization degrees.

In this way, different types of inert gases injected into the first and second induction heating chambers 21 and 22, respectively, are the size of the crucible 1, the type and amount of graphitization material charged in the crucible 1, and induction heating. The graphitization of the graphitized material by the pressure condition of the space 23, the frequency condition of induction heating, etc. can also be selected according to the experience value.

As another example of the above-described gas injection process, in an embodiment of the present invention, in a state in which the second opening 32 is opened through the first opening and closing member 35, the first and second induction heating chambers 21 and 22 ), any one of nitrogen gas and argon gas is injected into the induction heating space 23 through the gas injection unit 37 into the induction heating space 23 of the .

That is, in the embodiment of the present invention, since the induction heating space 23 of the first and second induction heating chambers 21 and 22 is interconnected through the second opening 32, the first and second induction The same inert gas (any one of nitrogen gas and argon gas) may be injected into the induction heating space 23 of the heating chambers 21 and 22 .

Accordingly, in the embodiment of the present invention, an inert gas is injected into the induction heating space 23 of the first and second induction heating chambers 21 and 22, and the inert gas is injected into the induction heating space 23. purging through

Furthermore, in the embodiment of the present invention, in the process of injecting the inert gas into the induction heating space 23 of the first and second induction heating chambers 21 and 22 through the gas injection unit 37 as described above, the A very small amount of hydrogen and a very small amount of oxygen may be injected as reaction gases into the induction heating space 23 through the gas injection unit 37 .

Next, in an embodiment of the present invention, an alternating current is applied to the induction heating coil unit 45 through a current generator. Then, in an embodiment of the present invention, a magnetic field is formed around the induction heating coil unit 45, and a current flow is generated in the crucible 1 by electromagnetic induction, and also graphitization inside the crucible 1 The material also causes an electric current to flow.

Accordingly, in the embodiment of the present invention, heat due to eddy current loss and hysteresis loss is generated in the crucible 1 and/or the graphitized material in the crucible 1 . That is, in the embodiment of the present invention, only the crucible 1 may be heated by induction heating, and the crucible 1 and the graphitized material may be heated simultaneously or sequentially.

Here, the simultaneous heating means that the crucible 1 and the graphitized material are induction heated at the same time.

And, the sequential heating means that the graphitized material is heated by the elevated temperature of the crucible 1 as the crucible 1 is inductively heated, and the sequentially heated graphitized material is inductively heated. That is, the temperature of the crucible 1 is raised by induction heating to generate heat, and the graphitized material is heated (indirectly heated) by the heat of the crucible 1 .

In an embodiment of the present invention, as an example, the crucible 1 and the graphitized material may be simultaneously heated by induction heating. In addition, the graphitized material may be indirectly heated by heating the crucible 1 at a low temperature, and indirect heating and induction heating (direct heating) may be simultaneously performed at a high temperature.

At this time, the crucible 1, the fixed thermal insulation module 41, the movable thermal insulation module 43, etc. may be oxidized (etched) due to oxygen during heating, etc., but in the embodiment of the present invention, The induction heating space 23 of the first and second induction heating chambers 21 and 22 is purged or made into a non-oxidizing atmosphere to protect the crucible 1, the fixed thermal insulation module 41 and the movable thermal insulation module 43, etc. contamination can be prevented.

Therefore, in the embodiment of the present invention, the graphitized material inside the crucible 1 is heated and graphitized by the heat of the crucible 1, and the graphitized material is heated (indirectly heated) to carbonize or graphitize a part. Then, as the graphitized material, which is partially carbonized or graphitized, is induction heating (direct heating), the heating efficiency of the graphitized material can be increased.

The series of processes as described above has been described as induction heating of each crucible 1 at the same time in the first and second induction heating chambers 21 and 22, but is not necessarily limited thereto, and the gripper module 39 is The crucible 1 may be moved, and the crucible 1 may be sequentially heated by the induction heating unit 20 in the first and second induction heating chambers 21 and 22 .

On the other hand, in the process of induction heating the crucible 1 through the induction heating unit 20 as described above, in the embodiment of the present invention, the heat generated in the crucible 1 and the graphitized material is the crucible 1 and It is transmitted to the temperature measuring tool 51 which is the same material.

Accordingly, in the embodiment of the present invention, the pyrometer 61 transmits energy radiated from the lower end of the temperature measuring tool 51 to the transparent window 55 at the top of the first and second induction heating chambers 21 and 22 . It is sensed and converted into an electric signal, and the electric signal is processed to measure the heating temperature of the crucible 1 and/or the graphitized material.

On the other hand, in a state in which the graphitized material inside the crucible 1 is graphitized through the induction heating unit 20 in the first and second induction heating chambers 21 and 22 through a series of processes as described above. , In an embodiment of the present invention, the movable thermal insulation module 43 is moved upwardly together with the induction heating coil unit 45 by the driving of the driving unit 47 .

Next, in the embodiment of the present invention, all of the first, second, and third openings 31 , 32 , 33 or the third opening 33 are opened through the first opening and closing member 35 , and the fixed thermal insulation module 41 . The crucible 1 loaded thereon is gripped through the gripper module 39 , and the crucible 1 is taken out through the third opening 33 of the second induction heating chamber 22 .

Next, in the embodiment of the present invention, in a state in which the inlet 73 of the cooling chamber 71 is opened through the second opening and closing member 79, the crucible 1 is moved through the gripper module 39 to the cooling chamber 71 . Loaded on the second conveyor 81 inside.

Then, the crucible 1 is transferred to the outlet 75 side along the process direction by the second conveyor 81 , and the outlet 75 is closed by the second opening/closing member 79 . Accordingly, the crucibles 1 are accommodated in the cooling chamber 71 , and the inlet 73 is closed through the second opening and closing member 79 in a state where the operation of the second conveyor 81 is stopped.

Next, in the embodiment of the present invention, nitrogen gas or argon gas as a cooling medium is injected into the cooling chamber 71 through the cooling medium injection unit 77, and the crucibles 1 are cooled through the cooling medium. .

Then, in the embodiment of the present invention, the crucibles 1 cooled as described above are taken out through the outlet 75 of the cooling chamber 71 .

Therefore, in an embodiment of the present invention, graphitized artificial graphite may be manufactured by induction heating a graphitizing material such as coke powder through a series of continuous processes as described above.

3 is a view showing another example of a crucible applied to the continuous graphitization apparatus according to an embodiment of the present invention.

3, in the embodiment of the present invention, the graphitization material is not charged in the crucible 1 (hereinafter referred to as the main crucible for convenience) as described above, but a plurality of sub crucibles ( 99) may be arranged inside the main crucible (1).

The main crucible 1 is provided with a size that can accommodate the sub crucibles (99). In addition, the sub crucibles 99 are stacked up and down in pairs inside the main crucible 1 . Furthermore, graphitization materials of different materials may be charged in the sub crucibles 99, and the upper ends of the sub crucibles 99 are for closing the upper ends so that the graphitization materials of different materials do not mix. A cover 99a may be installed.

For example, the sub crucibles 99 may be provided in eight stacked pairs in the vertical direction in pairs in four regions equally partitioned from the inner center of the main crucible 1 .

Here, each pair of sub crucibles 99 stacked in the vertical direction as described above are disposed in contact with the inner wall of the main crucible 1 based on the inner center of the main crucible 1 . This is to easily transfer the heat generated in the main crucible 1 to the sub crucibles 99 .

Therefore, in the embodiment of the present invention, the main crucible 1 in which the plurality of sub crucibles 99 are accommodated as described above is inductively heated in a series of continuous processes as described above, and the graphite charged in the sub crucibles 99 . Graphitized materials can be graphitized.

Hereinafter, the effect of the continuous graphitization apparatus 100 according to an embodiment of the present invention will be described with reference to the accompanying drawings.

4 to 8 are views for explaining the effect of the continuous graphitization apparatus according to embodiments of the present invention.

First, the embodiment of the present invention (Example 1 in the drawing) has a structure in which the temperature measuring tool 51 is inserted into the movable insulation module 43 of the induction heating unit 20 . And other embodiments (Example 2 in the drawing) are based on the structure of the electric embodiment (Example 1 in the drawing), and a plurality of (8) as a small crucible (described in the drawing) inside the main crucible 1 Dog) has a configuration in which the sub crucibles 99 are arranged.

As comparative examples in contrast to the embodiments of the present invention, the graphitization furnace structure to which the Etcheson furnace is applied (Comparative Example 1 in the drawing), the graphitization furnace structure to which the resistance heating furnace is applied (Comparative Example 2 in the drawing), and An induction heating structure (Comparative Example 3 in the drawing) in which the temperature measuring tool 51 is not applied to the movable thermal insulation module 43 will be presented.

4, when comparing the graphitization crystallinity through XRD for the Examples according to the present invention and the comparative examples described above, the graphitization degree (graphitization crystallinity) in Examples 1 and 2 is compared It can be seen that it is superior to the examples.

Here, d ₀₀₂ is the interplanar distance in the crystal, and the value decreases as the graphitization degree increases, Lc (002) is the crystal size in the C-axis direction, and the value increases as the graphitization degree increases, and La (110) is a As the crystal size in the axial direction, the value increases as the graphitization degree increases.

Therefore, it can be seen that Example 1 is excellent when comprehensively considering _{not only the above d 002} and graphitization degree, but also electrode density, initial capacity, 3 ^{rd capacity, initial efficiency, and stability of equipment output, which will be described further later.}

Referring to Figure 5, when artificial graphite obtained by graphitizing a graphitized material through the examples according to the present invention and the comparative examples described above is applied to the negative electrode material of the battery, when comparing the electrochemical properties of the negative electrode material, It can be seen that the electrode density, the initial capacity (charge/discharge capacity) and the third capacity (3rd capacity) in Examples 1 and 2 are increased compared to Comparative Examples, and due to this, in Examples 1 and 2, It can be seen that the initial efficiency of

In other words, the higher the electrode density, the greater the capacity can be because many active materials can be filled in the same volume. In general, the capacity loss is the greatest as the SEI layer is formed during the first charge/discharge, and the higher the initial efficiency, the smaller the loss value that affects the subsequent charge/discharge capacity, so the larger the initial efficiency value is.

Here, 3 ^rd is the high capacity, the capacity index may be higher because the degree emerges when repeatedly charging and discharging stably also the value. As a result, referring to Examples 1 and 2, since the electrode density, 3rd capacity, and initial efficiency are higher than those of the comparative examples, it can be seen that there is an advantage according to the application of the induction heating method and the temperature measuring tool 51 . .

Referring to FIG. 6 , when artificial graphite obtained by graphitizing the graphitized material in Example 1 and Comparative Example 1 according to the present invention is applied to the negative electrode material of the battery, the graphitization degree by region through Raman spectroscopy for the negative electrode material When comparing , it can be seen that the graphitization degree in Example 1 is uniform compared to Comparative Example 1.

Specifically, the D peak intensity (Id) of Raman spectroscopy is a peak detected when there are many defects with a low graphitization degree, and the G peak (Ig) is a peak detected when the graphitization degree is high. Accordingly, when the graphitization degree is decreased, the Id/Ig value increases and the Ig/Id value decreases.

Accordingly, in the case of Id/Ig, the graphitization degree decreases as the number of red regions increases, and in the case of Ig/Id, the graphitization degree increases as the number of green regions increases. As a result, in the case of Id / Ig + Ig / Id, the more green areas and less red areas, the higher the graphitization degree, and in the case of Example 1, since there are more green areas than Comparative Example 1, it can be confirmed that the graphitization degree is high. .

Referring to FIG. 7 , when graphitizing a graphitized material through Example 1 and Comparative Example 3 according to the present invention, when comparing changes in electrical output characteristics of equipment, Example 1 operates differently from Comparative Example 3 Since the temperature measuring tool 51 of the same material as the crucible is applied to the insulation module 43 , stable temperature measurement is possible through energy radiated from the lower end of the temperature measuring tool 51 .

Therefore, in Example 1 of the present invention, since stable and reliable temperature measurement is possible through the temperature measuring tool 51, the change in electrical output due to induction heating of the crucible/graphitized material by applying an alternating current is shown in Comparative Example 3 It can be seen that it is more stable than For this reason, in Embodiment 1 of the present invention, it is possible to reduce the amount of power consumed by reaching the crucible/graphitizing material to a set temperature.

That is, in the case of Comparative Example 3, which does not use the temperature measuring tool 51, it is difficult to secure the flatness of the measuring surface and the constancy of the emissivity. It can be seen that there are limits.

8, in the case of graphitizing the graphitized material through Example 1 and Comparative Example 3 according to the present invention, in Comparative Example 3, during graphitization of the graphitized material through induction heating, the movable insulation module 43 It is impossible to measure the normal temperature of the crucible/graphitized material due to the decomposition of the insulation material.

However, in Example 1 of the present invention, since the temperature measuring tool 51 of the same material as the crucible is applied to the movable thermal insulation module 43, even if the thermal insulation material decomposition of the movable thermal insulation module 43 occurs, the temperature measurement tool 51 ), it is possible to measure the stable temperature of the crucible/graphitized material through the energy radiated from the lower end.

Therefore, in the present embodiment 1, since the heating temperature of the crucible/graphitization material can be measured by sensing the energy radiated through the lower end of the temperature measuring tool 51 of the heat of the crucible/graphitized material, the homeostasis of the temperature measurement site And by securing flatness, improving the thermal emissivity, and removing the temperature measurement disturbance due to the decomposition of the insulating material, stable and reliable temperature measurement of the crucible/graphitized material is possible.

According to the continuous graphitization apparatus 100 according to the embodiment of the present invention as described so far, the crucible is inductively heated as a continuous process including the graphitizing material crucible charging, the induction heating process of the crucible, and the cooling process, and the graphite Graphitized materials can be graphitized.

Therefore, in the embodiment of the present invention, since the graphitized material can be graphitized in a continuous process by induction heating, the facility utilization rate and operational productivity can be improved, and the investment cost can be reduced by reducing the heating equipment of the graphitized material. .

Furthermore, in the embodiment of the present invention, since the graphitized material can be graphitized by induction heating, the heating efficiency of the graphitized material can be increased due to the principle of induction heating, and thereby the high quality of the graphitized artificial graphite Quality can be secured, and the cost of heating the graphitized material can be reduced.

Although the embodiments of the present invention have been described above, the technical spirit of the present invention is not limited to the embodiments presented in this specification, and those skilled in the art who understand the technical spirit of the present invention can configure, within the scope of the same technical spirit. Other embodiments may be easily proposed by adding, changing, deleting, or adding elements, but this will also fall within the scope of the present invention.

1: Crucible 3: Base frame
10: crucible transfer unit 11: first conveyor
20: induction heating unit 21: first induction heating chamber
22: second induction heating chamber 23: induction heating space
25: bulkhead 31: first opening and closing port
32: second opening 33: third opening
35: first opening and closing member 37: gas injection unit
39: gripper module 41: fixed thermal insulation module
43: movable insulation module 45: induction heating coil unit
47: driving unit 51: temperature measuring tool
53: finish plate 55: transparent window
61: pyrometer 70: cooling unit
71: cooling chamber 73: inlet
75: outlet 77: cooling medium injection unit
79: second opening and closing member 81: second conveyor
99: sub crucible 99a: cover
100: continuous graphitization device

Claims (15)

a crucible transfer unit for transferring the crucibles charged with the graphitized material along a set transfer path;
an induction heating unit for induction heating the crucible transferred through the crucible transfer unit in at least one induction heating chamber and graphitizing the graphitized material; and
a cooling unit cooling the crucible discharged from the induction heating unit to a temperature set in a cooling chamber;
A continuous graphitization device comprising a. According to claim 1,
The induction heating chamber,
Doedoe provided to be interconnected as a plurality through a partition wall between the crucible transfer unit and the cooling unit,
A continuous graphitization apparatus comprising: a first opening/closing opening formed on the transfer path side; a second opening/closing opening formed on the partition wall; and a third opening/closing opening opening formed on the cooling chamber side. 3. The method of claim 2,
The induction heating chamber,
A continuous graphitization apparatus including an opening and closing member for opening and closing the first, second, and third openings, respectively. 3. The method of claim 2,
The induction heating chamber,
A continuous graphitization apparatus including a gas injection unit for injecting an inert gas and a reactive gas into the inner space. According to claim 1,
The induction heating unit,
a fixed insulation module fixedly installed on the inner bottom surface of the induction heating chamber and supporting the crucible;
a movable thermal insulation module installed to be movable in the vertical direction with respect to the fixed thermal insulation module;
An induction heating coil unit installed to be connected to the movable thermal insulation module and surrounding the crucible on the fixed thermal insulation module inside
A continuous graphitization device comprising a. 3. The method of claim 2,
The induction heating chamber,
A continuous graphitization apparatus including a gripper module installed in the interior space and configured to load and unload the crucible with respect to the fixed thermal insulation module. 7. The method of claim 6,
The induction heating unit,
A temperature measuring tool made of the same material as the crucible, which is installed through the movable insulation module in the vertical direction, and the lower end is located at the upper end of the crucible when the movable insulation module is lowered
Continuous graphitization apparatus further comprising a. 8. The method of claim 7,
The temperature measuring tool is
A continuous graphitizing device made of a graphite material and provided in a cylindrical shape with an open top and a closed bottom. 9. The method of claim 8,
The induction heating chamber,
The continuous graphitization device is installed on the upper end, and further comprises a transparent window made of a quartz material exposing the lower end of the temperature measuring tool to the outside. 10. The method of claim 9,
The induction heating chamber,
A pyrometer for measuring the heating temperature of the crucible by sensing energy radiated from the lower end of the temperature measuring tool through the transparent window
Continuous graphitization apparatus further comprising a. According to claim 1,
The cooling chamber,
an inlet for introducing the crucible discharged from the induction heating unit into an internal space;
an outlet for discharging the crucible to the outside;
A cooling medium injection unit for injecting a cooling medium into the inner space
A continuous graphitization device comprising a. 12. The method of claim 11,
The cooling chamber,
Continuous graphitization apparatus further comprising an opening and closing member for selectively opening and closing the inlet and outlet. 12. The method of claim 11,
The cooling unit is
and a conveyor disposed between the inlet and the outlet in the inner space of the cooling chamber. According to claim 1,
The crucible is
A continuous graphitization device made of graphite material and provided with a thickness satisfying 0.1 to 4.0 times the depth of current penetration. According to claim 1,
A continuous graphitization apparatus in which a plurality of sub crucibles are disposed inside the crucible.

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