KR20170009165A

KR20170009165A - Dielectric barrier discharge device for particles

Info

Publication number: KR20170009165A
Application number: KR1020150100757A
Authority: KR
Inventors: 김윤기
Original assignee: 한밭대학교 산학협력단
Priority date: 2015-07-16
Filing date: 2015-07-16
Publication date: 2017-01-25
Also published as: KR101710273B1

Abstract

The present invention relates to a dielectric barrier discharge device for processing a fine particle which can continuously perform surface cleaning, modifying, and activating processes of a fine particle like micro or nano-powder or a glass fiber by using plasma discharge under an atmospheric pressure environment.

Description

{DIELECTRIC BARRIER DISCHARGE DEVICE FOR PARTICLES}

The present invention relates to a dielectric barrier discharge apparatus, and more particularly, to a dielectric barrier discharge apparatus capable of continuously carrying out surface cleaning, modification, and activation treatment of fine particles such as micro or nano powder or glass fiber using a plasma discharge under an atmospheric pressure environment. Barrier discharge device.

Plasma surface treatment is a technology recognized as clean technology unlike wet process using existing chemical agent, and industrial application is increasing recently. Among them, surface cleaning and modification using Atmospheric Pressure Dielectric Barrier Discharge (APDBD) are widely used in displays, semiconductors and electronic parts industries, and proved to be stable and applicable.

The surface treatment using the atmospheric pressure dielectric barrier discharge is advantageous in that it is simple in structure, inexpensive and in-line continuous production because it does not use a chamber structure and a device for vacuum.

However, the surface treatment using atmospheric pressure dielectric barrier discharge has been mainly developed for metal, ceramic, and polymer materials in flat plate form, and application of surface treatment of powder material having a size of several tens of microns has been studied in only a few studies Level.

The reason for this is that due to the nature of the atmospheric pressure discharge process, since the flow rate of the discharge gas is very high and the flow rate is fast, a complicated structure for shielding and recovery due to the scattering of powder in the surface treatment of the powder material has to be added. The simplicity of the structure and the low cost characteristics can not be utilized.

In this situation, it is more difficult to apply atmospheric pressure dielectric barrier discharge for the surface treatment of nanoparticles with very fine particle size.

However, as the size of powder recently used becomes finer to the level of tens of nanometers, surface treatment technology that helps to improve the dispersibility of particles or to bind strongly with other materials becomes more important. Recently, application of nano powder has been expanded Accordingly, there is a continuing need for a surface treatment technique for improving the characteristics.

Korean Patent No. 10-0924723 (April 4, 2009 announcement)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a dielectric barrier discharge device for processing fine particles, which can continuously process fine particles through atmospheric pressure dielectric barrier discharge.

In order to achieve the above-mentioned object, the present invention provides a dielectric barrier discharge apparatus comprising: a charging unit including a supply unit for receiving fine particles charged to the upper side and quantitatively supplying fine particles through a first hopper formed at a lower side in a dropping manner; A discharge unit formed of a high voltage electrode and a ground electrode which are covered with a dielectric and formed with a discharge region through which the falling fine particles pass, and a power supply unit which supplies a power having a pulse of a specific period to the high voltage electrode; A gas injection unit injecting a reaction gas into a lower side of the discharge region; A gas discharge unit having a filter for discharging the reaction gas to the upper side of the discharge region and filtering out the fine particles; A collecting part for receiving the fine particles passing through the discharge area through the second hopper formed on the upper side and passing through the second hopper; .

An air flow path formed outside the discharge unit, an electrode cooling unit including an air injection unit and an air discharge unit formed on one side and the other side of the air flow path, respectively; .

The supply unit may include a supply member having a plurality of grooves provided in a lower portion of the first hopper through a transverse axis and capable of accommodating the fine particles on an outer circumferential surface thereof, And a driving unit configured to drive the driving unit.

According to the present invention, it is possible to continuously carry out a large amount of surface modification of nanoparticles or micro-sized fine particle powders, thereby improving the dispersibility of powders, improving the mechanical properties of the composite, and improving the catalytic properties.

FIG. 1 is a front perspective view showing an external shape according to a preferred embodiment of the present invention,
FIG. 2 is a rear perspective view showing an outer shape according to a preferred embodiment of the present invention, FIG.
3 is a cross-sectional side view, in accordance with a preferred embodiment of the present invention,
4 is a first cross-sectional perspective view according to a preferred embodiment of the present invention,
Figure 5 is a second cross-sectional perspective view, in accordance with a preferred embodiment of the present invention,
6 is a cross-sectional view illustrating flow of fine particles and gas according to a preferred embodiment of the present invention.

Hereinafter, the structure of the dielectric barrier discharge device for treating fine particles of the present invention will be described in detail with reference to the accompanying drawings.

2 is a rear perspective view showing an outer shape according to a preferred embodiment of the present invention, FIG. 3 is a side sectional view according to a preferred embodiment of the present invention, and FIG. 4 FIG. 5 is a second cross-sectional perspective view of a preferred embodiment of the present invention. FIG.

In the present invention, the particle surface modification is performed by treating the fine particles using a dielectric barrier discharge method. In this case, the fine particles mentioned in the present invention mean ultrafine particles having a size of several tens of nanometers or micrometers, which is difficult to be continuously treated in a large amount by a conventional method using plasma, and may include glass fibers having the same diameter .

Further, in the present invention, in order to continuously process plasma of a large amount of fine particles, the fine particles are charged into the upper side so that the fine particles that are plasma-treated on the lower side can be recovered. .

For this purpose, a cover is formed on the upper part of the upper part, and a charging part 110 for receiving the fine particles charged by the user and supplying the fine particles for plasma processing is provided. At this time, the charging unit 110 includes a first storage unit 112 which receives the fine particles introduced through the cover and a lower part of which is partially opened. In the lower part of the first storage unit 112, The first hopper 111 is formed. Thereafter, a feeder 113 for dropping the fine particles collected under the first hopper 111 in a predetermined amount is provided. The supply unit 113 includes an opening / closing unit that can be opened / closed through external control, so that a certain amount of fine particles are dropped downward due to periodic opening.

In the preferred embodiment of the present invention, the supply unit periodically feeds fine particles in a rotating manner. For this purpose, the supply unit is installed along a shaft 114 formed in the lower part of the first hopper 111 in the transverse direction, There is provided a supply member 115 having a plurality of grooves 116 capable of accommodating the fine particles. In the accompanying drawings, a cross section of the supply member 115 is formed in a cross shape so that a total of four grooves are formed.

At this time, driving means such as an electric motor for rotating the supplying member 115 along the axis 114 is provided at the outer side, and a driving unit 118 for connecting the driving means and the supplying member 115 is formed.

That is, the fine particles collected downward through the first hopper 111 located above the supply part 113 are accommodated in the groove 116 located on the upper side of the supply member 115, As the means operates, the supply member 115 rotates through the shaft 114 and the grooves receiving the fine particles move downward, so that the received fine particles fall due to gravity.

And a discharge unit 120 for treating the dropped fine particles through a plasma discharge is provided below the charging unit 110. As described above, in the present invention, since the atmospheric pressure dielectric barrier discharge is used for the plasma discharge treatment, the discharge region 124 through which the fine particles falling down through the supply portion 113 pass is interposed between the front and rear surfaces The high voltage electrode 121 and the ground electrode 122, which are respectively covered with a dielectric material 123,

The shape and area of the high voltage electrode 121 and the ground electrode 122 may be appropriately adjusted so that the time for the falling particles to be exposed to the plasma discharge becomes longer or the plurality of the discharge units 120 may be continuously formed It is possible. In the preferred embodiment of the present invention, two sets of the discharge units 120 are provided in the upper and lower parts so as to be sufficiently exposed to the plasma discharge in order to increase the processing efficiency.

A power supply having a pulse having a specific period is supplied to the high voltage electrode 121 through a separate power supply unit 125 so that a dielectric barrier discharge is generated in the discharge region 124, The discharge is performed through the discharge region 124.

Generally, a plasma discharge is generated when secondary electrons are generated by collision of positive ions in a plasma as a voltage of about several hundreds of volts is applied to an electrode, and they are accelerated by an external electric field and collide with neutral gas particles to accelerate again while ionizing gas particles A glow discharge is used in which an electric current flows between the electrodes while an electronic situation occurs by an iterative process. However, in the atmospheric pressure environment as in the present invention, the glow discharge shows a very unstable state, and the discharge gas rapidly transitions to an arc discharge with a large current, so that the temperature of the discharge gas becomes very high. There arises a problem that it becomes impossible to apply to the processing.

The dielectric discharge plasma is a method of lowering the temperature of the plasma in an atmospheric pressure environment so as to achieve a stable discharge, and at least one dielectric 123 is inserted between a pair of electrodes, that is, the high voltage electrode 121 and the ground electrode 122 Thereby preventing direct discharge between the electrodes made of the metal material and preventing the glow discharge from transitioning to the arc discharge. In addition, such a dielectric discharge method is useful for the surface treatment of a material that is susceptible to heat, such as a polymer material, at a low temperature of room temperature due to a stable discharge because the concentration of active radical is 100 to 1000 times higher than that of a conventional low pressure plasma You will get the advantage that you can.

In addition, as described above, in order to ionize the gas through collision between the positive and neutral gas particles in the plasma, a neutral reactive gas such as argon (Ar) and helium (He) is injected into the discharge region from the outside. And a gas discharging portion for discharging the reacted gas.

6 is a cross-sectional view illustrating flow of fine particles and gas according to a preferred embodiment of the present invention.

At this time, the injected neutral gas is injected to the lower side of the discharge region 124 as shown in FIG. 6 so as to have a pressure of 1 atm or close to the atmospheric pressure, and is discharged upward. That is, since the flow of the reaction gas is made from the lower side to the upper side, the gas slowly flows in the direction opposite to the direction in which the fine particles fall, so that the fine particles are floated in the discharge region 124, So that the surface treatment can be performed by exposing to the plasma discharge for a longer time.

For this purpose, the gas injection unit 140 is formed so as to be formed obliquely from the lower side to the upper side so that the gas can be supplied toward the upper side rather than vertically supplying the gas into the discharge region. In order to prevent fine particles from being mixed and discharged into the discharged gas, the gas discharging unit 150 includes a filter 151 for passing only gas and filtering out fine particles, So that the filtered fine particles can be dropped again.

In the preferred embodiment of the present invention, as shown in the accompanying drawings, the high voltage electrode 121 and the ground electrode 122 are respectively formed with a gas injection unit 140 so that the injected gas is branched and supplied in a plurality of straight lines. The positions of the gas injection unit 140 formed on the sides of the high voltage electrode 121 and the ground electrode 122 are shifted from each other to minimize swirling flow and unnecessary flow in addition to the gas flow from the lower side to the upper side.

Then, the fine particles passing through the discharge unit 120 fall downward and are collected and contained in the collecting unit 160 through the lower second hopper 161. A second storage part 162 is formed in the collecting part 160 to accommodate the processed fine particles so that the user can open the cover to take out the fine particles stored in the second storage part 162 .

At this time, a receiving portion 163 composed of a receiving member having receiving grooves formed on the lower side of the second hopper 161 of the collecting portion 160 is rotatable through a shaft like the supplying portion 113, It is possible to periodically move the fine particles exposed to the discharge to the second storage part 162.

As described above, as the plasma discharge continues, heat is generated on the side of the high-voltage electrode 121 and the ground electrode 122, resulting in a decrease in the efficiency of surface modification and, in the case where the temperature is continuously increased, .

In the present invention, the electrode cooling unit 130 is configured to prevent the high voltage electrode 121 and the ground electrode 122 from being continuously cooled through the air during the plasma discharge. The electrode cooling unit 130 includes an air flow path 131 formed for smoothly flowing air to the outside of the discharging unit 120, that is, the high voltage electrode 121 and the ground electrode 122, An air injection unit 132 for supplying air from the outside to one side and an air exhaust unit 133 for discharging the air inside the air flow path 131 to the outside.

It is to be understood that the invention is not limited to the disclosed embodiment, but is capable of many modifications and variations within the scope of the appended claims. It is self-evident.

110: input portion 111: first hopper
112: first storage unit 113:
114: shaft 115: supply member
116: groove 118:
120: discharging part 121: high voltage electrode
122: ground electrode 123: dielectric
124: discharge region 125: power source section
130: electrode cooling unit 131: air flow path
132: air injection unit 133: air discharge unit
140: gas injecting part 150: gas discharging part
151: filter 160:
161: second hopper 162: second storage section
163:

Claims

In the dielectric barrier discharge device,
A charging unit 110 for receiving the fine particles introduced to the upper side and having a supply unit 113 for supplying the fine particles in a predetermined amount in a falling manner through the first hopper 111 formed at the lower side;
A high voltage electrode 121 and a ground electrode 122 which are formed with a discharge region 124 through which the falling fine particles pass and are covered with a dielectric 123; A discharging unit 120 including a power supply unit 125 for supplying power;
A gas injection unit 140 for injecting a reaction gas into the lower side of the discharge region 124;
A gas discharge unit 150 having a filter 151 for discharging the reaction gas to the upper side of the discharge region 124 and filtering out the fine particles;
A collecting unit 160 for receiving the fine particles passing through the discharge region 124 through the second hopper 161 formed on the upper side; Wherein said dielectric barrier discharge device is a dielectric barrier discharge device for treating fine particles.

The method according to claim 1,
An air flow path 131 formed outside the discharge part 120 and an air injection part 132 and an air discharge part 133 formed on one side and the other side of the air flow path 131, A cooling unit 130; Wherein the dielectric barrier discharge device further comprises:

The method according to claim 1,
The supply unit 113 includes a supply member 115 provided below the first hopper 111 and having a plurality of grooves 116 which are installed on the outer circumferential surface of the first hopper 111 in the horizontal direction and can accommodate the fine particles, And a drive unit (118) coupled to the supply member (115) to rotate the supply member (115).