KR20220105961A - Rotary kiln - Google Patents

Abstract

According to the present invention, a rotary kiln includes a material plasticity device mixing a powdery material while heating the material. The material plasticity device includes: a heating member including a body having a hollow hole, and a microwave generation part provided in the body, and generating a microwave; and a plasticity member provided in the hollow hole of the body, mixing the powdery material while rotating in a horizontal direction, and heating the powdery material through the microwave of the microwave generation part. The plasticity member includes: a cylindrical tube provided in the hollow hole of the body to be rotatable in a horizontal direction, and having a through part formed on a circumferential surface with which the microwave generation part repetitively comes in contact; and a cylindrical ceramic tube provided on the inside of the metal tube, mixing the powdery material while rotating in interoperation with the metal tube, and absorbing or transmitting the microwave of the microwave generation part through an exposed surface exposed from the through part to heat the powdery material. Therefore, the present invention is capable of effectively heating powdery materials.

Description

Rotary kiln {ROTARY KILN}

The present invention relates to a rotary kiln to which a microwave heating method is applied. In particular, the present invention relates to a rotary kiln capable of increasing the absorption or transmission power of microwaves.

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, then putting it into a heating device and sintering at a high temperature.

In this case, a rotary kiln may be applied as the heating device. The rotary kiln accommodates a precursor for positive electrode active material production and a lithium raw material (hereinafter referred to as a powder raw material), a rotating tube for mixing by rotating in a horizontal direction, is provided on the outside of the rotating tube and adds heat to the rotating tube to obtain the powder It includes a heating element for heating and reacting the raw material.

That is, the rotary kiln is a conductive type heat transfer method in which heat is transferred from a container and the outside before heat is transferred to the powder raw material. However, the rotary kiln has a problem in that it takes a lot of time to reach thermal equilibrium (temperature increase) for reacting the powder raw material, and a temperature deviation occurs locally.

In order to solve such a problem, the rotary kiln uses an internal heating method using microwave waves, and thus the powder raw material can be effectively heated.

However, there is a limit in increasing the absorption or transmission power of microwave waves only with the conventional rotary kiln structure, and thus there is a limit in rapidly heating the powder raw material.

Patent Publication No. 10-2004-0069156.

In order to solve the above problems, the present invention can increase the absorption or transmission power of microwave waves by applying a plastic member including a metal tube and a ceramic tube having a patterned hole formed therein, and as a result, the powder raw material can be heated quickly. An object of the present invention is to provide a rotary kiln that can be

The rotary kiln of the present invention for achieving the above object includes a raw material firing device for mixing and heating powder raw materials, and the raw material firing device, a body having a hollow body, and a microwave wave provided in the body A heating member including a microwave generating unit for generating; and a sintering member provided in the hollow of the main body, mixing the powdered raw material while rotating in the horizontal direction, and heating the powdered raw material by the microwave wave of the microwave generating unit, wherein the sintering member is the hollow of the main body a cylindrical metal tube rotatably provided in the horizontal direction and having a through portion formed on a circumferential surface that the microwave generator repeatedly contacts with; And it is provided on the inside of the metal tube and mixes the powder raw material while rotating in conjunction with the metal tube, and absorbs or transmits the microwave wave of the microwave generating part through the exposed surface exposed to the through part to heat the powder raw material. It may include a cylindrical ceramic tube.

The through portion may include a plurality of through holes penetrating from the outer circumferential surface to the inner circumferential surface of the metal tube, and the plurality of through holes may have a regular pattern along the circumferential surface of the metal tube.

The through hole may have any one shape of a triangle, a square, a pentagon, a circle, and an oval.

The through hole may have an isosceles triangle shape, and the through hole in the isosceles triangle shape may have a zigzag pattern in which vertices between two sides having the same length face each other.

A plurality of the microwave generator may be provided in the body along the longitudinal direction of the plastic member, and a plurality of the through portions may be formed in the metal tube to correspond to the plurality of microwave generators.

The metal tube may have a penetration portion formed in an area of 50 to 90% of a total area.

A coupling hole to which the microwave generator is coupled is formed in the body, and the coupling hole may be formed to penetrate from the outside of the body to the hollow.

The microwave generating unit may be located inside the outlet of the coupling hole so as not to protrude out of the outlet of the coupling hole located in the hollow.

The body may be made of a heat insulating material.

and a raw material supply device for supplying a powder raw material to the raw material firing device, wherein the raw material supply device includes: a hopper in which the powder raw material is stored; It may include a supply blocking unit that blocks the microwave wave from leaking between the raw material firing apparatus.

and a raw material recovery device for recovering a powder raw material that has been fired through the raw material firing device, wherein the raw material recovery device includes a recovery unit configured to recover a powdered raw material that has been fired through the raw material firing device, the recovery unit and the It may include a recovery blocking unit that blocks the microwave wave from leaking between the raw material firing apparatus.

The metal tube may have a thinner thickness than the ceramic tube.

A support protrusion may be formed on the inner circumferential surface of the coupling hole located in the hollow to support the microwave generator so as not to protrude out of the outlet of the coupling hole located in the hollow.

The rotary kiln of the present invention includes a raw material firing device for mixing and heating powder raw materials at the same time, wherein the raw material firing device is heated by a heating member generating microwave waves, absorbing or transmitting microwave waves, and heating the powder raw materials The firing member is characterized in that it includes a metal tube having a through-portion formed therein, and a ceramic tube whose exposed surface exposed through the through-portion absorbs or transmits microwave waves to heat the powder raw material. Due to such a characteristic, it is possible to increase the absorption or transmission power of microwave waves, and accordingly, the powder raw material can be quickly heated.

In addition, in the present invention, the through portion of the rotary kiln includes a plurality of through holes, and the plurality of through holes have a regular pattern along the circumferential surface of the metal tube. Due to these characteristics, the ceramic tube can absorb or transmit microwave waves uniformly, and as a result, the powder raw material can be effectively heated.

1 is a perspective view showing a rotary kiln according to a first embodiment of the present invention.
Figure 2 is a front view showing the rotary kiln according to the first embodiment of the present invention.
Figure 3 is a sectional view showing a rotary kiln raw material supply device according to the first embodiment of the present invention.
Figure 4 is an assembly perspective view showing a firing member included in the raw material firing apparatus of the rotary kiln according to the first embodiment of the present invention.
Figure 5 is an exploded perspective view showing a firing member included in the raw material firing apparatus of the rotary kiln according to the first embodiment of the present invention.
6 is a partial cross-sectional view showing a raw material firing apparatus of the rotary kiln according to the first embodiment of the present invention.
7 is an overall cross-sectional view showing a firing member included in the raw material firing apparatus of the rotary kiln according to the first embodiment of the present invention.
8 is a perspective view showing another example of a plastic member included in the rotary kiln according to the first embodiment of the present invention.
9 is a cross-sectional view showing a rotary kiln raw material recovery device according to the first embodiment of the present invention.
10 is a cross-sectional view showing a rotary kiln according to a second embodiment of the present invention.
11 is a cross-sectional view showing a rotary kiln according to a third embodiment of the present invention.

Hereinafter, 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 embodied in several different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

[Rotary kiln according to the first embodiment of the present invention]

As shown in FIGS. 1 to 8, the rotary kiln according to the first embodiment of the present invention is a raw material supply device 100 for supplying a powder raw material 1, and the raw material supply device 100 is supplied through the A raw material calcination device 200 for mixing (or stirring) and heating the powder raw material 1, and a raw material recovery device 300 for recovering the powder raw material 1 that has been calcined by the raw material calcination device 200. include

raw material feeder

The raw material supply device 100 is for supplying a powder raw material, and the hopper 110 in which the powder raw material 1 is stored, and the powder raw material 1 stored in the hopper 110 are supplied to the raw material firing apparatus 200 . It includes a transfer unit 120 for supplying, and a supply blocking unit 130 for blocking the microwave wave from leaking between the transfer unit 120 and the raw material firing apparatus 200 .

On the other hand, the raw material supply device 100 further includes a gas input unit for injecting gas into the raw material firing device 200 to react with the powdered raw material, and the gas input unit is the raw material firing device 200 through the hopper 110 . inject gas into

On the other hand, the supply cut-off unit 130 has heat resistance, and accordingly, it is possible to block the heat generated in the raw material firing apparatus 200 from being transmitted to the hopper 110 through the supply cut-off unit 130 , and as a result, the hopper (110) can be protected.

Raw material firing equipment

The raw material firing device 200 is for mixing and heating the powder raw material supplied from the raw material supply device, and absorbs the microwave wave generated by the heating member 210 and the heating member 210 for generating microwave waves. or a sintering member 220 for heating and mixing the powder raw material by permeation.

The heating member 210 includes a body 211 having a hollow 211a that penetrates in the longitudinal direction (left and right direction when viewed in FIG. 2), and is provided in the body 211 to generate microwave waves. It includes a microwave generator 212 .

A coupling hole 211b to which the microwave generator 212 is coupled is formed in the main body 211 . Here, the coupling hole 211b is formed to penetrate from the outside (ie, the outer surface) of the main body 211 to the hollow 211a, and thus the microwave generating unit 212 is conveniently coupled to the coupling hole 211b. or can be separated. And the coupling hole (211b) can be positioned in contact with (ie, as close as possible) to the microwave generating unit 212 and the plastic member 220 coupled to the main body 211.

At this time, the microwave generating unit 212 may be screw-coupled to the coupling hole 211b, thereby increasing the coupling property of the microwave generating unit 212 .

Here, in order to prevent friction between the microwave generating unit 212 and the plastic member, the microwave generating unit 212 does not protrude out of the outlet of the coupling hole 211b located in the hollow 211a. That is, the microwave generating unit 212 is located inside the outlet of the coupling hole (211b).

On the other hand, the body 211 may be provided with a heat insulating material, thereby preventing external loss of heat generated in the plastic member 220 . In addition, the main body 211 may further include a heating element that generates heat by power, and the heating element heats the metal tube and the ceramic tube, and heats the powder raw material through the heated ceramic tube.

On the other hand, between both ends of the main body 211 and the firing member 220, a shielding portion for blocking microwave waves from leaking out through between the body 211 and the firing member 220 may be included.

On the other hand, the microwave generating unit 212 has a coupling portion 212a coupled to the coupling hole 211b, and a support portion 212b that has a larger diameter than the coupling portion 212a and is supported on the outer circumferential surface of the main body 211. includes Accordingly, the microwave generating unit 212 can be easily coupled to the coupling hole (211b).

On the other hand, the microwave generator 212 refers to an oscillator that generates a microwave wave when power is applied.

That is, the microwave generator 212 is for generating microwave waves. Here, the microwave wave is also referred to as a microwave, and generally refers to a radio wave having a frequency of 3 million megacycles and a wavelength of 1 m or less. In more detail, the microwave generator 212 emits a microwave wave in a frequency range of about 300 MHz to about 300 GHz.

Accordingly, the microwave generator 212 may generate heat by vibrating the water remaining in the powder raw material 1 as a wave when the microwave wave is absorbed into the powder raw material 1, and as a result, the powder raw material 1 can be heated.

On the other hand, the microwave generating unit 212 may be provided with a plurality of hollow 211a of the main body 211 in the longitudinal direction and the circumferential direction, thereby stably generating microwave waves toward the plastic member.

The sintering member 220 is for mixing and heating powder raw materials, and has a dual structure including a cylindrical metal tube 221 with a through-portion formed therein, and a cylindrical ceramic tube 222 .

The cylindrical metal tube 221 is provided to be rotatable in the horizontal direction in the hollow 211a of the main body 211 (rotating around the horizontal horizontal central axis o of the metal tube when viewed in FIG. 2), A penetrating portion is formed on the circumferential surface (part A shown in FIG. 6 ) in contact with the microwave generator repeatedly.

Here, the through portion includes a plurality of through-holes 221a penetrating from the outer circumferential surface to the inner circumferential surface of the metal tube 221 , and the plurality of through-holes 221a have a uniform pattern along the circumferential surface of the metal tube 221 . .

That is, the plurality of through-holes 221a have any one shape of a triangle, a quadrangle, a pentagon, a circle, and an oval, and the through-holes 221a having any one shape of a triangle, a quadrangle, a pentagon, a circle, and an oval are metal. It may be formed in a regular or irregular pattern on the circumferential surface of the tube 221 .

For example, the through-hole 221a, referring to FIG. 4, has an isosceles triangular shape. The through-hole 221a of the isosceles triangular shape zigzags so that the vertices between the two sides of the same length are facing each other. has a pattern arranged in

As another example, referring to FIG. 8 , the through-hole 221a has a rectangular shape and a pattern arranged along the circumferential surface of the metal tube 221 .

Here, a plurality of through portions may be formed in the metal tube to correspond to the plurality of microwave generators 212 . That is, a plurality of microwave generating units 212 are provided in the longitudinal direction of the main body 211 , and a plurality of through portions are formed in the longitudinal direction of the metal tube 221 to correspond to the plurality of microwave generating units 212 . .

On the other hand, the metal tube 221 forms a penetrating portion only in a set area among the total area so that the strength is not weakened below the set value. That is, the metal tube 221 has a penetration portion formed in an area of 50 to 90% of the total area, and preferably, the penetration portion is formed in an area of 60 to 70% of the total area of the metal tube 221 . Accordingly, it is possible to secure the penetration portion in the metal tube as much as possible, and at the same time to prevent deformation due to weakening of strength.

Meanwhile, the metal tube 221 may be made of a material including one or two or more of carbon steel, heavy chrome steel, sus steel, ferrite-based steel, and martensite-based steel.

The cylindrical ceramic tube 222 is provided inside the metal tube 221 and rotates in conjunction with the metal tube 221 to mix the powder raw material 1 supplied from the raw material supply device, and the through part The exposed surface 222a exposed to the microwave generator 212 absorbs or transmits the microwave wave, and heats the powder raw material 1 by the microwave wave.

Meanwhile, the ceramic tube 222 may be made of a material including any one or two or more from the group consisting of quartz, mullite, alumina, aluminum nitride, and silicon nitride.

On the other hand, the inside of the ceramic tube 222 may further include a heating element for heating the powder raw material while heating by microwave waves, the heating element is any one of silicon carbide (SiC), boron nitride (BN), and carbon material Or it may be made of two or more materials. Here, the microwave can raise the silicon carbide (SiC) to about 1800°C. Here, the heating element may be contained in the ceramic tube, coated on the inner circumferential surface of the ceramic tube, or provided to protrude from the inner circumferential surface of the ceramic tube.

In the raw material firing apparatus 200 having such a configuration, the powder supplied to the firing member 220 while the firing member 220 provided in the hollow 211a of the main body 211 of the heating member 210 rotates in the horizontal direction. The raw material (1) is mixed. At this time, the microwave wave of the microwave generator 212 is absorbed or transmitted to the exposed surface of the ceramic tube 222 exposed through the penetrating portion of the metal tube 221 included in the plastic member 220, and the ceramic tube As the microwave wave absorbed or transmitted to the sintering member 220 is absorbed by the powder raw material, it is possible to rapidly heat the powder raw material. In particular, as the microwave wave absorbed or transmitted in the ceramic tube heats the heating element included in the ceramic tube 222, the powder raw material can be heated more quickly.

On the other hand, the raw material firing device 200 further includes a rotating device 230 for rotating the firing member 220 in a horizontal direction, the rotary device 230 is a driving gear coupled to the shape surrounding the firing member 220 ( 231 ) and a driving motor 232 for rotating the driving gear 231 to horizontally rotate the plastic member 220 through the driving gear 231 .

Raw material recovery device

The raw material recovery device 300 is for recovering a powder raw material that has been calcined by the raw material calcination device. and a recovery blocking part 320 that blocks the microwave wave from leaking between the recovery part 310 and the raw material firing apparatus 200 .

Therefore, the rotary kiln according to the first embodiment of the present invention can increase the absorption or transmission power of microwave waves, and in particular, by adjusting the size of the penetrating portion formed in the metal tube, the absorption or transmission power of the microwave wave can be adjusted. As a result, the powder raw material can be stably mixed and heated at the same time.

Hereinafter, the operating state of the rotary kiln according to the first embodiment of the present invention will be described.

[Operating method of the rotary kiln according to the first embodiment of the present invention]

First, the plastic member 220 is rotated through the rotating device 230 . Then, the plastic member 220 rotates in the horizontal direction in the hollow 211a formed in the body 211 of the heating member 210 . Then, the ceramic tube 222 of the firing member 220 has an exposed surface 222a exposed through the penetration portion of the metal tube 221 , a microwave generator 212 provided in the body 211 of the heating member 210 . and is in contact repeatedly, and at this time, the exposed surface 222a of the ceramic tube 222 absorbs or transmits the microwave wave generated by the microwave generator 212 . And the microwave wave absorbed or transmitted to the ceramic tube is absorbed by the powder raw material 1 supplied to the ceramic tube and heats the powder raw material 1, and as a result, the powder raw material can be effectively heated. In particular, as the microwave wave absorbed or transmitted in the ceramic tube heats the heating element included in the ceramic tube 222, the powder raw material can be heated more quickly.

Here, gas is introduced into the firing member 220 through a gas input unit and reacts with the powder raw material 1 , and the gas discharged from the firing member 220 is recovered through a gas discharge unit provided in the raw material recovery device.

Thereafter, the raw material powder 1, which has been calcined by the calcination member 220 , is stored while being recovered through the raw material recovery device 300 .

Hereinafter, in describing another embodiment of the present invention, the same reference numerals are used for components having the same functions as those of the above-described embodiment, and overlapping descriptions will be omitted.

[Rotary kiln according to the second embodiment of the present invention]

The rotary kiln according to the second embodiment of the present invention includes a plastic member 220 having a metal tube 221 and a ceramic tube 222 as shown in FIG. 10 , the metal tube 221 . has a thinner thickness than the ceramic tube 222 .

That is, the thickness α of the metal tube 221 has a thickness of 30 to 60% of the thickness β of the ceramic tube 222 .

Therefore, in the rotary kiln according to the second embodiment of the present invention, the exposed surface of the ceramic tube 222 exposed through the through portion of the metal tube 221 and the microwave generating unit 212 may be closer to each other, and as a result The exposed surface of the ceramic tube 222 may more stably absorb or transmit the microwave wave of the microwave generator.

[Rotary kiln according to the third embodiment of the present invention]

The rotary kiln according to the third embodiment of the present invention is, as shown in FIG. 11, a body 211 having a hollow 211a formed therein, and a microwave generating unit coupled to the coupling hole 211b of the main body 211. and a heating element 210 having a 212 .

The microwave generator 212 may be located inside the outlet so as not to protrude out of the outlet of the coupling hole 211b located in the hollow 211a.

In particular, the outlet of the coupling hole 211b located in the hollow 211a may further include a support protrusion 211c for supporting the microwave generating unit 212 so as not to protrude out of the coupling hole 211b. Contact between the wave generator 212 and the plastic member 220 can be prevented in advance.

On the other hand, one or more support protrusions 211c may be formed on the inner circumferential surface of the coupling hole 211b.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and various embodiments derived from the meaning and scope of the claims and their equivalent concepts are possible.

100: raw material feeder
110: hopper
120: transfer unit
130: supply cut-off
200: raw material firing device
210: heating member
211: body
211a: hollow
211b: coupling hole
212: microwave generating unit
220: plastic member
221: metal tube
221a: through hole
222: ceramic tube
300: recovery device
310: recovery unit
320: return blocking unit

Claims (13)

It includes a raw material firing device for mixing and heating powder raw materials,
The raw material firing device,
a heating member including a hollow body and a microwave generator provided in the body and generating microwave waves; and
It is provided in the hollow of the main body, mixes the powder raw material while rotating in the horizontal direction, and includes a firing member for heating the powder raw material through the microwave wave of the microwave generator,
The plastic member includes a cylindrical metal tube rotatably provided in the hollow of the main body in a horizontal direction and having a penetration portion formed on a circumferential surface in contact with the microwave generator repeatedly, and the metal tube and provided inside the metal tube. A rotary kiln comprising a cylindrical ceramic tube which mixes the powder raw material while rotating in conjunction and absorbs or transmits the microwave wave of the microwave generating part through the exposed surface exposed to the penetrating part to heat the powder raw material. The method according to claim 1,
The through portion includes a plurality of through holes penetrating from the outer circumferential surface to the inner circumferential surface of the metal tube,
A plurality of through holes rotary kiln having a regular pattern along the circumferential surface of the metal tube. 3. The method according to claim 2,
The through hole is a rotary kiln having any one shape of a triangle, a square, a pentagon, a circle, and an oval. 3. The method according to claim 2,
The through hole has an isosceles triangle shape, the through hole of the isosceles triangle shape is a rotary kiln having a pattern arranged in a zigzag so that the vertices between the two sides of the same length are facing each other. The method according to claim 1,
A plurality of the microwave generating unit is provided in the body along the longitudinal direction of the plastic member,
A rotary kiln in which a plurality of the penetrating portion is formed in the metal tube to correspond to a plurality of microwave generating units. The method according to claim 1,
The metal tube is a rotary kiln in which a penetration portion is formed in an area of 50 to 90% of the total area. The method according to claim 1,
A coupling hole is formed in the body to which the microwave generator is coupled,
The coupling hole is a rotary kiln that is formed to penetrate from the outside of the main body to the hollow. 8. The method of claim 7,
The microwave generating unit rotary kiln positioned inside the outlet of the coupling hole so as not to protrude out of the outlet of the coupling hole located in the hollow. The method according to claim 1,
The main body is a rotary kiln provided with an insulating material. The method according to claim 1,
Further comprising a raw material supply device for supplying a powder raw material to the raw material firing device,
The raw material supply device includes a hopper in which powder raw materials are stored, a transfer unit for supplying the powder raw material stored in the hopper to the raw material calcination apparatus, and a supply blocking unit for blocking microwave waves from leaking between the transfer unit and the raw material calcination apparatus rotary kiln. The method 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 rotary kiln comprising a recovery part for recovering the powdered raw material fired through the raw material firing device, and a recovery blocker for blocking the microwave wave from leaking between the recovery part and the raw material firing device. The method according to claim 1,
The metal tube is a rotary kiln having a thinner thickness than the ceramic tube. 9. The method of claim 8,
A rotary kiln having a support protrusion formed on the inner circumferential surface of the coupling hole located in the hollow to support the microwave generating unit so as not to protrude out of the exit of the coupling hole located in the hollow.

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