KR20220116829A - Rotary kiln - Google Patents

Abstract

The present invention relates to a rotary kiln, and more specifically, to a rotary kiln which can resolve the heat deviation between the adjacent portion of the inner wall surface and the central portion in the burning tube, and can resolve the quality deviation of a burned product corresponding to the location within the burning tube. To this end, the rotary kiln according to the present invention comprises a raw material burning device which mixes a powder raw material while simultaneously heating the same. The raw material burning device comprises: a main body in which a hollow hole is formed; a heat supply unit which is provided at the main body, and supplies heat to the heating tube; the heating tube which is provided at the hollow hole of the main body, while being rotationally provided in a horizontal direction; and a heat radiating structure which is provided in the burning tube, and decreases the temperature deviation within the burning tube. The heat radiating structure comprises: a heat sink which is located at the central portion of the burning tube, and is formed in a longitudinal direction of the burning tube; and a heat pipe which is radially provided from the heat sink.

Description

rotary kiln {ROTARY KILN}

The present invention relates to a rotary kiln, and relates to a rotary kiln capable of improving the thermal deviation between the inner wall surface adjacent portion and the central portion of the firing tube and improving the quality variation of the fired product depending on the position inside the firing tube. .

In general, a secondary battery refers to a battery capable of charging and discharging unlike a primary battery that cannot be charged, and such secondary batteries are widely used in high-tech electronic devices such as phones, notebook computers, and camcorders.

In particular, as technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. Among these secondary batteries, a lithium secondary battery has a high energy density and voltage, has a long cycle life, and has a low self-discharge rate, so it is commercialized and widely used.

Meanwhile, in the lithium secondary battery, a lithium transition metal oxide is used as a positive electrode active material. In other words, lithium cobalt oxide with high operating voltage and excellent capacity characteristics, lithium nickel oxide with high reversible capacity of about 200 mAh/g and easy implementation of large-capacity batteries, and lithium nickel in which a part of nickel is substituted with cobalt, as a positive electrode active material Cobalt oxide, lithium nickel cobalt metal oxide in which a part of nickel is substituted with manganese, cobalt or aluminum, lithium manganese-based oxide having excellent thermal stability and low cost, and lithium iron phosphate having excellent stability are used. The cathode active material is prepared by mixing a precursor for producing a cathode active material and a lithium raw material (hereinafter, referred to as a powder raw material), then putting it into a heating device and sintering at a high temperature.

As a firing device for manufacturing a secondary battery cathode material, an RHK device (Roller Hearth Kiln) is generally used. The RHK device fills the saggar with a firing material, stacks the saggars in multiple layers and arranges them, enters the firing furnace, and sinters at a high temperature for a certain period of time. However, the RHK apparatus is a step-type process method, and a temperature gradient may occur depending on the position of the saggar, so there is a limit to the continuous manufacturing process.

In this regard, a rotary kiln may be applied as a firing apparatus. The rotary kiln may include a raw material supply device, a raw material firing device, and a raw material recovery device as shown in FIG. 1 , and receives a powder raw material that is a firing material from the raw material supply device, in a horizontal direction from the firing tube of the raw material firing device Rotate to mix. The rotary kiln can secure the fluidity of the plastic material through the rotation of the rotating tube, and has advantages in uniformity and continuity compared to the RHK device through continuous material supply.

However, since the rotary kiln sinters the powder raw material in a conductive heat transfer method that is heated from the container and the outside before heat is transferred to the powder raw material, there is a problem in that heat deviation occurs depending on the position inside the sintering tube, which is a sintered product cause quality deviations. Accordingly, there is a need to develop a device capable of solving the above problems and securing a fired product of uniform quality.

The present invention has been devised to solve the above problems, and an object of the present invention is to improve the thermal deviation between the inner wall surface adjacent portion and the central portion of the inner wall of the firing tube, and the quality deviation of the fired product according to the position inside the firing tube It is to provide a rotary kiln that can improve

The rotary kiln according to the present invention includes a raw material firing device for mixing and heating powder raw materials, and the raw material firing device includes a hollow body, a heat supply unit provided in the body, and supplying heat to the firing tube, the main body It is provided in the hollow and is provided in the firing tube and the firing tube rotatably provided in the horizontal direction, and includes a heat dissipation structure for reducing the temperature deviation inside the firing tube, and the heat dissipation structure is located at the center of the firing tube, It includes a heat sink formed in the longitudinal direction of the tube and a heat pipe provided in a radial direction from the heat sink.

The heat sink may include a body having a hollow therein, and a disk-shaped heat dissipation fin that is continuously arranged along the longitudinal direction of the body from the outer circumferential surface of the body.

The heat pipe may connect the inner wall of the firing tube and the heat sink.

At least two heat pipes may be provided on the same plane formed in the radial direction of the heat sink to form a heat pipe assembly.

In the heat pipe assembly, angles formed by at least two or more heat pipes may be the same.

At least two heat pipe assemblies may be provided to be spaced apart from each other in the longitudinal direction of the heat sink.

The heat pipe assembly may be provided such that the heat pipes constituting the heat pipe assembly are positioned to correspond to each other on the heat pipe and the heat sink of another adjacent heat pipe assembly.

The body may be formed of a heat insulating structure.

The heat supply unit may include an electric furnace provided above and below the firing tube.

The raw material firing apparatus may further include a rotating part for rotating the firing tube.

Further comprising a raw material supply device for supplying a powder raw material and a reaction gas to the raw material calcination device, the raw material supply device is a raw material input unit to which the powder raw material is input and stored, and a transfer unit for supplying the powder raw material stored in the raw material input unit to the raw material calcination device and a gas input unit for supplying gas to the raw material firing apparatus.

The raw material recovery device further includes a raw material recovery device for recovering the powdered raw material that has been fired through the raw material firing device, wherein the raw material recovery device includes a recovery unit for recovering the fired powder material through the raw material firing device and the reaction gas for which the reaction is completed in the raw material firing device It may include a gas discharge unit for discharging the.

The heat dissipation structure is provided along the length direction of the firing tube, and may further include an auxiliary heat pipe connecting the heat pipes of another heat pipe assembly adjacent to the heat pipe end of the heat pipe assembly.

The heat pipe assembly may be provided such that the heat pipes constituting the heat pipe assembly are staggered from each other on the heat pipe and the heat sink of another adjacent heat pipe assembly.

The rotary kiln according to the present invention includes a raw material firing device for mixing and heating powder raw materials, and the raw material firing device includes a hollow body, a heat supply unit provided in the body and supplying heat to the firing tube, and in the hollow of the body and a firing tube provided rotatably in the horizontal direction and a heat dissipation structure provided inside the firing tube to reduce a temperature deviation inside the firing tube, wherein the heat dissipation structure is located at the center of the firing tube and in the longitudinal direction of the firing tube It includes a heat sink formed and a heat pipe provided in a radial direction from the heat sink, thereby improving the thermal deviation between the inner wall surface adjacent portion and the central portion in the interior of the plastic tube, and Quality deviation can be improved.

1 is a cross-sectional view showing a conventional rotary kiln from the side.
Figure 2 is a cross-sectional view showing the rotary kiln according to the first embodiment of the present invention from the side.
3 is a perspective view showing a firing tube and a heat dissipation structure of the rotary kiln according to Example 1 of the present invention.
4 is a cross-sectional view illustrating a view after cutting along line A-A' of FIG. 3 .
5 is a front view showing a firing tube and a heat dissipation structure of the rotary kiln according to Example 1 of the present invention.
6 is a perspective view showing a firing tube and a heat dissipation structure of the rotary kiln according to the second embodiment of the present invention.
7 is a perspective view illustrating a firing tube and a heat dissipation structure of a rotary kiln according to a third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily carry out the present invention. However, the present invention may be implemented in several different forms and is not limited or limited by the following examples.

In order to clearly explain the present invention, detailed descriptions of parts irrelevant to the description or related known technologies that may unnecessarily obscure the gist of the present invention have been omitted, and in the present specification, reference signs are added to the components of each drawing. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

In addition, the terms or words used in the present specification and claims should not be construed as being limited to conventional or dictionary meanings, and the inventor appropriately defines the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Example 1

Figure 2 is a cross-sectional view showing the rotary kiln according to the first embodiment of the present invention from the side. 3 is a perspective view showing a firing tube and a heat dissipation structure of the rotary kiln according to Example 1 of the present invention. 4 is a cross-sectional view illustrating a view after cutting along A-A' of FIG. 3 . 5 is a front view showing a firing tube and a heat dissipation structure of the rotary kiln according to Example 1 of the present invention.

Referring to FIG. 2 , the rotary kiln according to Embodiment 1 of the present invention may include a raw material firing apparatus 100 , a raw material supply apparatus 200 , and a raw material recovery apparatus 300 .

The raw material firing apparatus 100 is an apparatus for mixing and heating the powder raw material supplied from the raw material input unit 210 of the raw material supply apparatus 200 , and will be described separately below in detail.

The raw material supply apparatus 200 is an apparatus for supplying a powder raw material and a reaction gas to the raw material firing apparatus 100 , and may include a raw material input unit 210 , a transfer unit 220 , and a gas input unit (not shown). . A powder raw material is input and stored in the raw material input unit 210 , and the powder raw material may be a precursor for the production of a cathode active material and a lithium raw material required for the production of the cathode active material. Here, the raw material input unit 210 may be in the form of a hopper. The transfer unit 220 supplies the powder raw material stored in the raw material input unit 210 to the raw material calcination apparatus 100, and the gas input unit supplies a gas therein to the raw material calcination apparatus 100 to react with the powder raw material. .

The raw material recovery device 300 is a device for recovering a powdered raw material that has been fired through the raw material firing device 100 , and may include a recovery unit 310 and a gas discharge unit 320 . The recovery unit 310 may recover a powder raw material that has been calcined through the raw material calcination apparatus 100 , and the gas discharge unit 320 may discharge a reaction gas in which the reaction is completed in the raw material calcination apparatus 100 .

Hereinafter, the raw material firing apparatus 100 will be described in detail with reference to FIGS. 2 to 5 . The raw material firing apparatus 100 includes a body 110 , a heat supply unit 120 , a firing tube 130 , and a heat dissipation structure 140 .

First, as shown in FIG. 2 , a hollow is formed in the body 110 , and a firing tube 130 is provided in the hollow, and the heat supply unit 120 is also provided in the body 110 to the firing tube 130 . provide heat In this case, the main body 110 is formed in a heat insulating structure to prevent the heat supply unit 120 and the heat of the fired tube 130 , which has received heat from the heat supply unit 120 , from being lost to the outside, thereby increasing thermal efficiency.

Next, the heat supply unit 120 is a device serving to supply heat to the firing tube 130 to sinter the powder raw material inside the firing tube 130 . For example, the heat supply unit 120 may be an electric furnace that generates heat by power, and is provided above and below the firing tube 130 to supply heat to the firing tube 130 . However, the type and location of the heat supply unit 120 is not limited to the electric furnace provided above and below the above-mentioned firing tube 130, and various methods capable of supplying heat to the powder raw material that is the firing material inside the firing tube 130 are used. It may include a heat source.

The firing tube 130 is provided in the hollow of the main body 110 and is rotatably provided in the horizontal direction. The firing tube 130 has a hollow cylindrical shape in which a space is formed so that a plastic material can be accommodated therein, and the material of the firing tube 130 is quartz, mullite, alumina, aluminum nitride, silicon nitride, carbon steel, heavy chrome steel, It may include any one or two or more of ceramic or metallic materials such as sus steel, ferrite-based steel, austenite steel, martensite-based steel, and the like.

Referring to FIG. 3 , the raw material firing apparatus 100 of the rotary kiln according to Embodiment 1 of the present invention may further include a heat dissipation structure 140 . The heat dissipation structure 140 is provided inside the firing tube 130 to reduce the temperature deviation inside the firing tube 130 , and is located in the center of the firing tube 130 as shown in FIG. 3 , and the firing tube 130 . ) includes a heat sink 141 formed in the longitudinal direction and a heat pipe 142 provided in a radial direction from the heat sink 141 . Accordingly, the rotary kiln according to the first embodiment of the present invention improves the thermal deviation between the inner wall surface adjacent portion and the central portion of the firing tube 130 , and improves the quality deviation of the fired product according to the location in the firing tube 130 . can do.

Hereinafter, the heat sink 141 and the heat pipe 142 of the heat dissipation structure 140 will be described in detail with reference to FIGS. 4 and 5 .

First, the heat sink 141 is configured to receive heat from the heat pipe 142 and radiate heat from the inside of the firing tube 130, and a body 141-1 and a heat dissipation fin 141- 2) may be included. The body 141-1 of the heat sink 141 may have a hollow formed therein, and there is no limitation in shape, but may preferably be a cylindrical shape having a length corresponding to the length of the firing tube 130 . The outer peripheral surface of the body 141-1 includes a disk or plate-shaped heat dissipation fin 141-2 that is continuously arranged along the longitudinal direction of the body 141-1 to increase the surface area, and through this Heat dissipation performance can be maximized.

In addition, at regular intervals of the body 141-1, including a plurality of nodes on which heat dissipation fins 141-2 are not formed, the nodes may be combined with a heat pipe 142 to be described later, and the body ( The heat dissipation fins 141-2 are not formed at both ends of 141-1), so that they can be coupled to the heat pipe 142.

The heat sink 141 may be made of any one or two or more of copper, aluminum, SiC, BeO, aluminum nitride, and carbon materials having high thermal conductivity.

Next, the heat pipe 142 is a pipe that transfers heat from the inner wall surface of the firing tube 130 to the center, and a heat sink 141 positioned at the inner wall surface of the firing tube 130 and the center of the firing tube 130 . ) can be connected. The heat pipe 142 exhausts the inside and puts a volatile liquid. When heat is applied to one side of the heat pipe 142, the liquid evaporates and moves to the other side with thermal energy to radiate heat, then again It is structured to return to its original position. Therefore, in the rotary kiln device in which heat is conducted from the outside of the firing tube 130 , the heat of the area adjacent to the inner wall surface of the firing tube 130 through the heat pipe 142 is transferred to the heat sink 141 at the center of the firing tube 130 . ), and through this, the thermal deviation inside the firing tube 130 can be improved, and the uniformity of the firing quality can be secured.

The body of the heat pipe 142 may be made of copper, stainless steel, ceramic, tungsten, or the like, and a porous fiber may be used for the inner wall of the heat pipe 142 . In addition, methanol, acetone, water, mercury, etc. may be used as the volatile material inside the heat pipe 142 .

As shown in FIGS. 3 and 5 , the heat pipe 142 according to the first embodiment of the present invention is provided with at least two or more heat pipes on the same plane formed in the radial direction of the heat sink 141 . The aggregate H may be formed, and each heat pipe 142 may be formed such that the angles formed by each of the heat pipes 142 are the same. For example, five heat pipes 142 are provided in a radial direction to one heat sink 141 provided in the center of the firing tube 130 to form a heat pipe assembly H, and each heat pipe 142 ) may be provided to form an angle of 72 degrees to each other. As such, when the plurality of heat pipes 142 are provided while forming the assembly H while forming the same angle, the heat of the inner wall surface of the firing tube 130 and the adjacent inner wall surface can be effectively transferred to the heat sink 141, In particular, it is possible to offset different thermal deviations depending on the position of the inner wall surface of the plastic tube 130 .

In addition, at least two heat pipe assemblies H may be provided to be spaced apart from each other in the longitudinal direction of the heat sink 141 , which is illustrated in FIG. 3 . In this case, it is possible to improve the thermal deviation in the longitudinal direction of the firing tube 130 as well as to improve the thermal deviation between the inner wall surface and the center of the firing tube 130, so that a fired product having better quality with improved uniformity can be obtained. can

In addition, the heat pipe assembly (H) corresponds to each other on the heat pipe 142 and the heat sink 141 of another heat pipe assembly (H) adjacent to which the heat pipes 142 constituting the heat pipe assembly (H) are adjacent to each other. It may be provided to be positioned.

In addition, the raw material firing apparatus 100 may further include a rotating part 150 for rotating the firing tube 130 , which is illustrated in FIG. 2 . The rotating unit 150 may include a driving gear (not shown) coupled to surround the firing tube 130 and a driving motor (not shown) for rotating the driving gear.

Example 2

6 is a perspective view showing a firing tube and a heat dissipation structure of the rotary kiln according to the second embodiment of the present invention.

In Embodiment 2 of the present invention, the heat dissipation structure 140 is different from Embodiment 1 in that it further includes an auxiliary heat pipe 143 . The contents common to the first embodiment will be omitted as much as possible, and the second embodiment will be described with a focus on the differences. That is, it is obvious that the content not described in the second embodiment may be regarded as the content of the first embodiment if necessary.

The rotary kiln according to the second embodiment of the present invention includes a raw material firing device 100 for mixing and heating powder raw materials, and the raw material firing device 100 includes a hollow body 110 and a body 110 . provided in the heat supply unit 120 for supplying heat to the firing tube 130, the firing tube 130 and the firing tube 130 provided in the hollow of the body 110 and rotatably provided in the horizontal direction. provided in the sintering tube 130, including a heat dissipation structure 140 for reducing the temperature deviation inside, the heat dissipation structure 140 is located in the center of the firing tube 130, the length direction of the firing tube 130 It includes a heat sink 141 formed of , and a heat pipe 142 provided in a radial direction from the heat sink 141 .

At least two heat pipes 142 may be provided on the same plane formed in the radial direction of the heat sink 141 to form a heat pipe assembly H, and the heat pipe assembly H includes at least two The mutual angles formed by the above heat pipes 142 may all be the same.

Referring to FIG. 6 , the heat dissipation structure 140 according to the second embodiment of the present invention is provided along the longitudinal direction of the fired tube 130 , and adjacent to the end of the heat pipe 142 of the heat pipe assembly (H). It may further include an auxiliary heat pipe 143 for connecting the heat pipes 142 of the other heat pipe assembly (H). Accordingly, the thermal deviation between the portion adjacent to the inner wall surface of the sintered tube 130 and the central portion thereof is improved, and in particular, it is possible to effectively improve the thermal deviation that may occur along the longitudinal direction of the sintered tube 130 .

Example 3

7 is a perspective view illustrating a firing tube and a heat dissipation structure of a rotary kiln according to a third embodiment of the present invention.

The third embodiment of the present invention is different from the first embodiment in that the heat pipes 142 of the heat pipe assembly (H) adjacent to each other are provided to be positioned alternately with each other. Contents common to Example 1 will be omitted as much as possible, and Example 3 will be described with a focus on differences. That is, it is self-evident that the content not described in the third embodiment may be regarded as the content of the first embodiment if necessary.

The rotary kiln according to the third embodiment of the present invention includes a raw material firing device 100 for mixing and heating powder raw materials, and the raw material firing device 100 includes a hollow body 110 and a body 110 . provided in the heat supply unit 120 for supplying heat to the firing tube 130, the firing tube 130 and the firing tube 130 provided in the hollow of the body 110 and rotatably provided in the horizontal direction. provided in the sintering tube 130, including a heat dissipation structure 140 for reducing the temperature deviation inside, the heat dissipation structure 140 is located in the center of the firing tube 130, the length direction of the firing tube 130 It includes a heat sink 141 formed of , and a heat pipe 142 provided in a radial direction from the heat sink 141 .

At least two heat pipes 142 may be provided on the same plane formed in the radial direction of the heat sink 141 to form a heat pipe assembly H, and the heat pipe assembly H includes at least two The mutual angles formed by the above heat pipes 142 may all be the same.

7, the heat pipe assembly (H) according to the third embodiment of the present invention is a heat pipe (H) of another heat pipe assembly (H) adjacent to which the heat pipes 142 constituting the heat pipe assembly (H) are adjacent. 142 ) and the heat sink 141 may be provided to be alternately positioned on each other. The configuration of the second embodiment, as in the first embodiment, the heat pipe 142 constituting the heat pipe assembly (H) is adjacent to the heat pipe 142 and the heat sink 141 of another heat pipe assembly (H). ), compared to the case where they are positioned to correspond to each other, more effectively offset different heat deviations depending on the position of the inner wall surface of the firing tube 130 , and transfer heat to the heat sink 141 to heat the entire firing tube 130 . It can greatly contribute to the improvement of deviation.

In the above, although the present invention has been described with reference to limited examples and drawings, the present invention is not limited thereto, and it is described below with the technical idea of the present invention by those of ordinary skill in the art to which the present invention pertains. Various implementations are possible within the scope of equivalents of the claims to be made.

100: raw material firing device
110: body
120: heat supply
130: firing tube
140: heat dissipation structure
141: heat sink
141-1: body
141-2: heat dissipation fins
142: heat pipe
143: auxiliary heat pipe
150: rotating part
200: raw material supply device
210: raw material input unit
220: transfer unit
300: raw material recovery device
310: recovery unit
320: gas outlet
H: heat pipe assembly

Claims (14)

It includes a raw material firing device for mixing and heating powder raw materials,
The raw material firing device,
a body in which a hollow is formed;
a heat supply unit provided in the body and supplying heat to the firing tube;
a firing tube provided in the hollow of the body and rotatably provided in a horizontal direction; and
a heat dissipation structure provided inside the firing tube and reducing a temperature deviation inside the firing tube;
The heat dissipation structure,
a heat sink positioned in the center of the firing tube and formed in a longitudinal direction of the firing tube; and
A rotary kiln comprising a heat pipe provided in a radial direction from the heat sink. According to claim 1,
The heat sink is
a body having a hollow formed therein;
A rotary kiln comprising a disk-shaped heat dissipation fin continuously arranged along the longitudinal direction of the body from the outer circumferential surface of the body. According to claim 1,
The heat pipe is
Rotary kiln, characterized in that connecting the inner wall of the firing tube and the heat sink. According to claim 1,
The heat pipe is
Rotary kiln, characterized in that at least two or more are provided on the same plane formed in the radial direction of the heat sink to form a heat pipe assembly. 5. The method of claim 4,
The heat pipe assembly,
A rotary kiln, characterized in that the mutual angles formed by at least two or more heat pipes are all the same. 5. The method of claim 4
The heat pipe assembly,
Rotary kiln, characterized in that at least two or more are provided spaced apart along the longitudinal direction of the heat sink. 7. The method of claim 6,
The heat pipe assembly,
The heat pipe constituting the heat pipe assembly is a rotary kiln, characterized in that it is provided so as to correspond to each other on the heat pipe and the heat sink of another adjacent heat pipe assembly. According to claim 1,
The body is
Rotary kiln, characterized in that it is formed in a thermal insulation structure. According to claim 1,
The heat supply unit,
Rotary kiln comprising an electric furnace provided above and below the firing tube. According to claim 1,
The raw material firing device,
Rotary kiln further comprising a rotating part for rotating the firing tube. According to claim 1,
Further comprising a raw material supply device for supplying a powder raw material and a reaction gas to the raw material firing device,
The raw material supply device,
a raw material input unit in which powder raw materials are input and stored;
a transfer unit for supplying the powdered raw material stored in the raw material input unit to the raw material firing device; and
Rotary kiln including a gas input for supplying gas to the raw material firing device. According to claim 1,
Further comprising a raw material recovery device for recovering the powder raw material fired through the raw material firing device,
The raw material recovery device,
a recovery unit for recovering a powdered raw material that has been fired through the raw material firing device; and
Rotary kiln including a gas discharge unit for discharging the reaction gas that has completed the reaction in the raw material firing device. 6. The method of claim 5,
The heat dissipation structure,
The rotary kiln further comprises an auxiliary heat pipe provided along the length direction of the firing tube and connecting the heat pipes of another heat pipe assembly adjacent to the heat pipe end of the heat pipe assembly. 6. The method of claim 5,
The heat pipe assembly,
The heat pipe constituting the heat pipe assembly is a rotary kiln, characterized in that it is provided so as to be staggered from each other on the heat pipe and the heat sink of another adjacent heat pipe assembly.

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