KR20160080600A - Carbon nanotube synthesis apparatus having impeller to control density of carbon nanotubes - Google Patents

Abstract

The present invention relates to an apparatus for synthesizing carbon nanotubes having an impeller for controlling density of carbon nanotubes. Instead of improving density of carbon nanotubes through multiple post-steps such as mixing, molding and drying in methods according to the related art, the present invention provides an apparatus for synthesizing carbon nanotubes while controlling density of carbon nanotubes by improving the shape of an impeller spraying a reaction gas onto a catalyst during the process for synthesizing carbon nanotubes in an apparatus for synthesizing carbon nanotubes. The apparatus for synthesizing carbon nanotubes comprises: a reaction chamber providing a space for forming carbon nanotubes; a catalyst supplying section for supplying a catalyst into the reaction chamber; an impeller having at least one rotating blade spraying a reaction gas onto the catalyst; and a reaction gas supplying tube for supplying the reaction gas into the impeller, wherein the rotating blade has a gas transfer line therein for receiving the reaction gas, a gas supplying hole is extended at the outer circumferential surface of the reaction gas supplying pipe for supplying the reaction gas to the gas transfer line, and the gas transfer line is formed at a position spaced apart from the linear line extending from the gas supplying hole horizontally.

Description

Technical Field The present invention relates to a carbon nanotube composite apparatus having an impeller for controlling the density of carbon nanotubes.

The present invention relates to a carbon nanotube synthesizer having an impeller for controlling the density of carbon nanotubes.

Carbon nanotube (CNT) is a carbon isotope composed of carbon, which is a substance in which one carbon atom is bonded to three different carbon atoms in a hexagonal honeycomb shape and has a tube diameter of several nanometers Which is a very small area of material.

Carbon nanotubes have superior electrical properties, mechanical properties, and thermal properties compared with homogeneous carbon isotopes. Therefore, active research has been conducted on high performance conductive composites, high strength / lightweight composites, heat dissipation / exothermic materials, electron emission sources, and transparent electrodes. Some are being commercialized.

Such carbon nanotubes can be prepared by various synthetic techniques. Examples of the synthesis methods include an arc discharge method, a laser vaporization method, a plasma enhanced chemical vapor deposition (PECVD) method, Thermal chemical vapor deposition (CVD) and electrolytic synthesis are known. Due to the structural control of the double carbon nanotubes, the size of the reactor, the conversion rate of the reaction gas, and the production efficiency, the fluidized bed synthesis equipment (carbon nanotube synthesis equipment) of the thermochemical vapor deposition method is very active.

Generally, when carbon nanotubes are used as a polymer composite material, carbon nanotubes are mixed with polymer pellets. The true density of single-stranded carbon nanotubes is 1.3 to 2.1 g / ml, but the bulk density of carbon nanotubes having a bundle type is 0.01 to 0.06 g / ml. < / RTI >

Furthermore, the apparent density of carbon nanotubes produced in fluidized bed synthesis equipment can be as low as 0.01-0.02 g / ml.

When carbon nanotubes having low apparent density are used in the field of composite materials, when the carbon nanotubes and the polymer pellets are put into the extruder together, the separation of the carbon nanotubes due to the high density of the two materials and the low density Dispersion problems are a stumbling block to the mass use of carbon nanotubes.

From the standpoint of the carbon nanotube producers, the packing cost and the distribution cost, which are increased due to the very low apparent density of the carbon nanotubes produced from the powder, are becoming burdensome.

Accordingly, various attempts have been made to improve the density of carbon nanotubes.

The following techniques are known to improve the apparent density of carbon nanotubes to date.

Korean Patent Laid-Open Publication No. 2014-0049859 discloses a method for producing a compressed CNT and a method for producing the same. The method comprises the steps of: preparing a nanotube clay by mixing a carbon nanotube with a solvent and a dispersant; shaping and cutting the prepared clay, A step of obtaining a pellet, and a step of removing the solvent contained in the clearing excess pellet obtained. In this method, unexpected side effects may be caused by the solvent and dispersant used in the manufacturing process. In addition, there is a problem in that the carbon nanotube is synthesized after the synthesis, compression and drying of the solvent and dispersant, There are drawbacks to the side.

Also disclosed in Korean Patent No. 10-0955295 is a method for producing a solid body including nano-carbon, which discloses a nano-carbon solid body including nano-carbon, metal (including oxide and ion), and resin. However, the nanocarbon solids prepared by this method contain metals and resins in order to increase the bonding force for solid-state molding. Therefore, when applied to a polymer composite material, a polymer used as a matrix, a metal contained in a nano- There is a problem in that it can not be used in a polymer composite material due to its reactivity or compatibility with a nano-carbon material, or the expression of important physical properties of nano-carbon may be deteriorated. There is a disadvantage that a process is required.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a carbon nanotube synthesis apparatus, in which the density of carbon nanotubes is improved through various post- An object of the present invention is to provide a carbon nanotube synthesizing apparatus which improves the shape of an impeller for injecting a reaction gas onto a catalyst during the process of synthesizing carbon nanotubes.

Accordingly, the present invention provides a reaction chamber for providing a space in which carbon nanotubes are formed; A catalyst supply unit for supplying a catalyst into the reaction chamber; An impeller having at least one rotating blade for spraying a reaction gas onto the catalyst; And a reaction gas supply line for supplying a reaction gas into the impeller, wherein the rotary vane has a gas delivery line for receiving a reaction gas inside thereof, and a reaction gas is supplied to an outer circumferential surface of the reaction gas supply line as a gas delivery line Wherein the gas supply line is formed at a position spaced horizontally from a straight line extending from the gas supply hole (an extension of the gas supply hole).

According to an embodiment of the present invention, the reaction gas supply pipe is formed to supply the reaction gas into the impeller through a support for rotation of the impeller, and the gas supply hole extends from the outer circumferential surface of the reaction gas supply pipe to the outer circumferential surface of the supporter do.

At this time, the gas transfer lines are horizontally spaced apart from the straight line extending the gas supply holes, and are partially overlapped with the straight line extending the gas supply holes, or arranged so as not to overlap the straight line extending the gas supply holes .

According to an embodiment of the present invention, the impeller has a body portion in which a rotating vane is formed, and a space for reactant gas flow is provided between the gas delivery line and the gas supply hole inside the body.

According to an embodiment of the present invention, the rotary vane has an inclined surface adjacent to a bottom surface formed with a plurality of spray holes and having a vertical cross-section, and the gas delivery line is horizontally spaced from a straight line extending a gas supply hole And the injection holes are sprayed to the upper part of the catalyst by receiving the reaction gas from the gas delivery line.

In the case of carbon nanotubes which improve the density by post-treatment such as a resin or an additive such as a solvent and a dispersant after synthesizing carbon nanotubes as in the above-mentioned prior art, when they are used in polymer composite materials due to the residual of additives, There arises a problem of deteriorating the excellent physical properties of the carbon nanotubes.

However, the present invention improves the density of carbon nanotubes directly in the process of synthesizing carbon nanotubes, rather than improving the density by adding additional additives to the carbon nanotube powder, none.

Further, the solidification process, which requires various post-treatment processes as in the prior art, requires considerable cost because additional materials and equipment are used, but in the present invention, there are no additional elements other than existing materials and equipment, There is a considerable advantage.

By using the carbon nanotubes with improved density, it is possible to solve the layer separation phenomenon due to the large density difference with the conventional polymer pellets, and to reduce the packing cost and the distribution cost of the material.

1 is a schematic view showing a carbon nanotube synthesizing apparatus using an impeller according to an embodiment of the present invention.
2 is a perspective view of an impeller according to an embodiment of the present invention,
3 is an exploded perspective view of an impeller according to an embodiment of the present invention.
4 is a bottom view and a cross-sectional view of an impeller according to an embodiment of the present invention;
FIG. 5 is a perspective view and a side view of a rotary blade of an impeller according to an embodiment of the present invention; FIG.
6 is a partial view showing a carbon nanotube synthesizing apparatus using an impeller according to an embodiment of the present invention.
7 is a cross-sectional view of a carbon nanotube synthesizer according to an embodiment of the present invention,
8 is a cutaway perspective view and a plan view showing a part of a carbon nanotube synthesizer according to an embodiment of the present invention,
9 is a plan view showing a part of the carbon nanotube synthesizer according to another embodiment of the present invention
10 is a graph showing experimental results illustrating the effect of improving the density of carbon nanotubes by using the impeller according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present applicant has disclosed a "carbon nanotube synthesizer" in Korean Patent No. 10-1126552 (Mar. 07, 2012).

The present invention is intended to control and increase the apparent density of carbon nanotubes by changing the structure of an impeller for spraying a reaction gas onto a catalyst and flowing a catalyst in the carbon nanotube synthesizer.

1, the carbon nanotube synthesis apparatus 100 includes a reaction chamber 110, a catalyst supply unit 120, a recovery unit 130, a plate 140, an impeller 200, a heating unit 170, An agitator 180, and an exhaust unit 190.

The reaction chamber 110 may be formed to provide a space in which the carbon nanotubes are synthesized (formed), may be a vertical type providing a space up and down and may be formed of a material resistant to heat such as quartz or graphite Lt; / RTI >

The reaction chamber 110 may be divided into a body portion where synthesis is performed, a lower end portion where the catalyst M is located, an upper end portion where the exhaust portion 190 is formed, and the like. The upper end of the reaction chamber 110 may be formed to have a diameter larger than that of the body portion, which increases the cross-sectional area of the upper end portion to lower the flow rate of the catalyst M or synthesized carbon nanotube reaching the upper end portion, So that it can fall back to the body part.

The catalyst supply unit 120 is connected to a catalyst storage unit (not shown) for storing the prepared catalyst M and supplies the catalyst M into the reaction chamber 110.

The recovery unit 130 is connected to the lower end of the reaction chamber 110 to discharge the synthesized carbon nanotube to the outside of the reaction chamber 110 to be recovered. Preferably, after completing the carbon nanotube synthesis process, the gate (not shown) provided in the recovery unit 190 is opened and the recovery unit 130 is maintained at a negative (-) pressure, It can be discharged and recovered.

The plate 140 is formed under the reaction chamber 110 so that the catalyst M provided inside the reaction chamber 110 can be positioned on the plate 140.

The heating unit 170 may be installed outside the reaction chamber 110 to heat the reaction chamber 110 to a process temperature required for synthesizing carbon nanotubes.

The stirrer 180 has a plurality of blades 184 for flowing the carbon nanotubes synthesized in the reaction chamber 110 and removing the deposit on the inner wall of the reaction chamber 110, And includes a wing 184, and is connected to a driving unit 186 that provides a rotational force.

The plurality of vanes 184 may be disposed at regular intervals around the rotation axis 182 and may be arranged in multiple stages along the length direction of the rotation axis 182. [ In addition, the blades 184 of each stage may be arranged to cross each other.

Here, the number and arrangement of the vanes 184 can be variously changed by those skilled in the art depending on the conditions such as the size of the reaction chamber 110, the kind of the reaction gas, the type of the catalyst M, and the like.

The stirrer 180 rotates about the rotation axis 182 with a constant period and improves the synthesis of carbon nanotubes by uniformly mixing the reaction gas and the catalyst M in the reaction chamber 110 to increase the rate of layer expansion . In addition, the stirrer 180 can prevent the problem that the synthesized carbon nanotube adheres to the wall surface of the reaction chamber 110.

The exhaust unit 190 may be connected to the upper end of the reaction chamber 110 to discharge the unreacted gas that has not reacted with the synthesis of the carbon nanotubes to the outside of the reaction chamber 110. That is, after the carbon nanotube synthesizing process is completed through the exhaust unit 190, residual gas and the like can be discharged to the outside.

1 to 5, the impeller 200 rotates while spraying the reaction gas onto the catalyst in the reaction chamber 110. The impeller 200 includes a body 210 connected to the support 150, And a plurality of rotating blades 220 integrally formed on the body 210. The rotating blade 220 rotatably supports at least one of the plurality of rotating blades 220 on the plate 140, Gas is injected.

The impeller 200 is connected to the support 150 and the support 150 is connected to the driving unit 152 to rotate the impeller 200 by the driving unit 152. The support 150 may be formed of, for example, ferrosil. The ferrosil can be composed of a magnetic seal and a magnet (not shown) formed inside the magnetic seal chamber of the ferrosilon rotates to rotate the supporter 150 so that the impeller 200 connected to the supporter 150 is rotated . At this time, when the impeller 200 rotates, the leakage of the gas inside the reaction chamber 110 through the gap where the driving unit 152 and the impeller 200 are coupled can be prevented by the sealing by the magnetic seal. Since the structure for sealing the inside of the shaft with the rotation of the shaft using the magnetic seal is well known in the art, a detailed description thereof will be omitted.

The reaction gas is supplied into the impeller 200 through the reaction gas supply pipe 160 and the reaction gas supply pipe 160 is connected to the impeller 200 through the support 150. The reaction gas supply pipe 160 is connected to a reaction gas supply unit 164 for supplying the reaction gas and a control valve 162 for regulating the supply amount of the reaction gas.

2 to 5, the rotating blades 220 of the impeller 200 are shown as two extending to both sides of the body 210, but are not limited thereto.

The impeller 200 is made of a Ti metal or a material which is not deformed at a high temperature. The impeller 200 is rotated at an arbitrary angle (for example, 15 to 60 degrees) around the body 210, And a vertical triangle having an equilateral triangle.

Each of the rotary vanes 220 is provided with a plurality of injection holes 222 for spraying the reaction gas supplied from the reaction gas supply pipe 160 to the bottom of the rotary vane 220. The reaction gas is supplied from the reaction gas supply pipe 160 to the impeller A gas transfer line 224 for transferring (supplying) the reaction gas supplied into the injection hole 222 to the injection hole 222 side is provided.

The gas delivery line 224 is formed in a straight shape extending in the extending direction (longitudinal direction) of the rotary vane 220 in the rotary vane 220, and a plurality of the injection holes 222 are formed on the bottom surface of the rotary vane 220 And are arranged in a line to form a linear alignment line.

At this time, the alignment line formed by the injection hole 222 and the injection hole 222 is not positioned directly under the gas transfer line 224, but is located diagonally with the gas transfer line 224.

In other words, the alignment line of the injection hole 222 is arranged at a position apart from the gas delivery line 224 by a certain distance in the horizontal direction (left and right sides).

Accordingly, the rotary blade 220 having a vertical triangular cross-section has an inclined surface adjacent to the bottom surface on which the plurality of the injection holes 222 are formed, and the alignment line formed by arranging the plurality of the injection holes 222 in a line is gas- And is horizontally spaced from the vertical lower side of the line 224 toward the slope side.

Since the alignment line of the injection hole 222 is formed at a position horizontally spaced apart from the vertical direction of the gas delivery line 224, the reaction gas injected onto the catalyst in the injection hole 222 is subjected to a reaction (For example, 10 to 60 degrees) with respect to the gas supply pipe 160. [0064]

In other words, the alignment line formed by the injection hole 222 and the injection hole 222 is not positioned vertically below the gas delivery line 224 and is positioned diagonally to the gas delivery line 224, 224 are sprayed onto the catalyst at an injection angle beta within a certain range.

The injection holes 222 formed in the rotary vanes 220 are disposed at an arbitrary interval from the reaction gas supply tubes 160. At this time, the injection holes formed in the rotary vanes at one side and the injection holes formed at the rotary vanes at the other side And the positions thereof are not overlapped with respect to the reaction gas supply pipe 160. That is, the injection holes formed in the rotary vane on one side and the injection holes formed on the rotary vane on the other side are located at different distances from the reaction gas supply tube 160.

Each injection hole 222 of the rotary vane 220 is formed to have a size of about 1.2 mm in diameter and the reaction gas is injected at a predetermined injection angle from the bottom surface (bottom surface) of the rotary vane 220.

In addition, the end of the gas delivery line 224 (the outer end of the rotary vane) is closed to prevent leakage of the reaction gas by the packing member 226.

6 to 8, a gas supply hole 166 for supplying a reaction gas to the gas transfer line 224 of each rotary vane 220 is formed on the outer peripheral surface of the upper end of the reaction gas supply tube 160 on both sides thereof And this gas supply hole 166 extends in the radial direction of the supporter 150 to the outer peripheral surface of the supporter 150.

7 and 8, the gas delivery lines 224 are arranged in a manner not aligned with the gas supply holes 166 extending in the radial direction of the supporter 150 but offset from each other.

The reaction gas supplied through the reaction gas supply pipe 160 is supplied to the inside of the body 210 of the impeller 200 for flow and supply of the reaction gas between the gas supply hole 166 and the gas delivery line 224, A space portion 212 is formed in order to allow gas to be supplied to the gas delivery line 224 through the gas supply hole 166. [

The space portion 212 is formed in the shape of a ring along the outer circumferential surface of the supporter 150 inside the body 210 so that the reaction gas supplied from the gas supply hole 166 flows into the gas transmission line 224, .

The impeller 200 is arranged at a position spaced apart from the gas transfer line 224 by a predetermined distance in the horizontal direction on a straight line extending from the gas supply hole 166, The carbon nanotubes in the reaction chamber 110 and the carbon nanotubes in the reaction chamber 110 can be prevented from entering the gas transfer line 224 through the space portion 212, The flow characteristics of the catalyst powder are controlled and controlled, and as a result, the apparent density improvement effect of the carbon nanotubes can be obtained.

In other words, by disposing the gas delivery line 224 of the impeller 200 at a horizontally spaced position (in a direction away from the slope of the rotary vane 220) on a straight line extending the gas supply hole 166 The density of carbon nanotubes can be adjusted according to the distance.

Here, the gas delivery line 224 is located on a straight line extending from the gas supply hole 166, and the reaction gas discharged from the gas supply hole 166 can flow smoothly into the gas delivery line 224 The distance in the horizontal direction between the gas delivery line 224 and the gas supply hole 166 is not limited.

For example, as shown in Fig. 8, the gas delivery line 224 may be arranged completely deviated from the gas supply hole 166 so as not to overlap on the straight line extending the gas supply hole 166, It is possible to arrange the gas supply holes 224 in a partially (half) overlapping manner on a straight line extending the gas supply holes 166.

In a specific example, the gas delivery line 224 is formed at a position 2.5 mm apart in the horizontal direction (specifically, in the direction away from the slope side of the rotary vane 220) on the straight line of the gas supply hole 166 It is possible.

In the above structure, the triangular cross section of the rotary vane 220 may be changed to another cross sectional shape, or the number of the injection holes 222, the position of the injection hole 222, and the size of the injection hole 222 may be changed. It is possible to control the flow characteristics of the carbon nanotubes and the catalyst powder and to control the flow characteristics of the carbon nanotubes and to improve the bulk density of the carbon nanotubes.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention, but the present invention is not limited thereto.

First, an impeller is prepared and prepared as in Example 1 and Comparative Example 1 below.

Example  One

Impeller # 1 for carbon nanotube synthesizer was fabricated using Ti metal. The impeller is provided on its left and right sides with two rotary blades forming an equilateral triangular section having an internal angle of 28 degrees on the upper side and the bottom surface of each rotary blade tapers in the longitudinal direction of the rotary blades to form an inclination angle of 8 degrees with the horizontal line And each of the rotary blades is provided with a gas delivery line for receiving the reaction gas from the reaction gas supply pipe on the inner side thereof and disposed on a diagonal line with the gas delivery line to form an angle of 60 ° at the bottom of the rotary blade The size of each injection hole is 1.2 mm, and the gas transfer line is spaced apart by a distance of 2.5 mm in the horizontal direction on the extension of the gas supply hole formed on both sides of the reaction gas supply pipe And is spaced apart.

Comparative Example  One

The impeller # 2 for a carbon nanotube synthesizer having the same structure as that of the first embodiment was manufactured in the same manner as in Example 1, except that the gas delivery line was arranged in a straight line with the gas supply holes extending in the radial direction of the support Respectively.

Experimental Example  One

Carbon nanotubes were prepared under the same conditions in the carbon nanotube synthesizer (fluidized bed synthesis equipment) equipped with the impeller # 1 of Example 1 and the impeller # 2 of Comparative Example 1.

Specifically, two carbon nanotube synthesizers were prepared, and the impellers of Example 1 and Comparative Example 1 were alternately installed for each synthesizer, and synthesis of carbon nanotubes was performed five times. The catalyst for the synthesis of carbon nanotubes was prepared as a catalyst for synthesizing multi-wall carbon nanotubes (300 g) at a synthesis temperature of 800 ° C., synthesis gas C2H4 / N2 = 120 / 40LPM and impeller 50RPM. .

The apparent density of the carbon nanotubes thus prepared was measured by a tapping method using a 100 ml container, and the measurement results are shown in FIG.

10, when the apparent density of the carbon nanotubes produced in the carbon nanotube synthesizer equipped with the impeller of Example 1 was lower than that of the carbon nanotubes synthesized in the carbon nanotube synthesizer equipped with the impeller of Comparative Example 1 It can be confirmed that the apparent density is increased.

10, in the fluidized bed synthesis equipment # 1, the apparent density of the carbon nanotubes was increased by 21.9% from 0.021 g / ml to 0.0256 g / ml by the impeller structure change. Also, in the fluidized bed synthesis equipment # 2 It was confirmed that the apparent density of the carbon nanotubes increased by 20.1% from 0.0208 g / ml to 0.025 g / ml due to the change of the impeller structure.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. Modifications are also included in the scope of the present invention.

100: Carbon nanotube synthesizer
110: reaction chamber
120:
130:
140: Plate
150: Support
160: Reaction gas supply pipe
166: gas supply hole
170:
180: stirrer
190:
200: Impeller
210:
212:
220: Rotating blade
222: injection hole
224: gas delivery line

Claims (5)

A reaction chamber for providing a space in which the carbon nanotubes are formed;
A catalyst supply unit for supplying a catalyst into the reaction chamber;
An impeller having at least one rotating blade for spraying a reaction gas onto the catalyst;
And a reaction gas supply pipe for supplying a reaction gas into the impeller,
A gas delivery line for supplying a reaction gas to the inner side of the rotary vane is formed and an outer peripheral surface of the reaction gas supply tube is formed with a gas supply hole for supplying a reaction gas to the gas delivery line, Wherein the carbon nanotube composite is formed at a position spaced horizontally from an extension of the hole.
The method according to claim 1,
Wherein the reaction gas supply pipe is formed to supply a reaction gas into the impeller through a support for rotation of the impeller and the gas supply hole extends from an outer circumferential surface of the reaction gas supply pipe to an outer circumferential surface of the supporter, Device.
The method according to claim 1,
Wherein the impeller has a body portion in which a rotating vane is formed, and a space for reactant gas flow is provided between the gas delivery line and the gas supply hole on the inner side of the body portion.
The method according to claim 1,
Wherein the rotary vane has an inclined surface adjacent to a bottom surface formed with a plurality of spray holes and having a vertical cross section of an equilateral triangle, and the gas transmission line is formed at a position spaced horizontally apart from an extension of the gas supply hole, Wherein the carbon nanotube synthesis device is a carbon nanotube synthesis device.
The method according to claim 1,
Wherein the rotary vane has a plurality of injection holes for injecting a reaction gas into the bottom surface thereof, and the injection holes are supplied with a reaction gas from the gas delivery line and injected onto the catalyst.

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