Dielectric powder sorting equipment

Abstract

The present invention discloses a dielectric powder sorting device, which includes a chamber, a lower electrode in the chamber, and an upper electrode disposed at an upper end of the chamber and spaced apart from the lower electrode, and when a dielectric powder is placed on the lower electrode and an AC electric field is applied, the dielectric powder is charged and an upward flow is induced to sort the dielectric powder, and the voltage and frequency are controlled to control the dielectric powder according to particle size, weight, density, dielectric constant, or surface area.

Description

[Technical Field]

[0001] The present invention relates to a dielectric powder sorting device that can easily sort dielectric powder by particle size, weight, density, dielectric constant, or surface area. [Background technology]

[0002] Powder sorting is widely used in industries such as paints, pigments, inks, and abrasives. Generally, powder sorting utilizes the difference in the magnitude of gravity and centrifugal or inertial forces acting depending on the size and mass of the powder. Powders can also be sorted based on the direction of externally applied force and flow. For example, when powder is induced to flow downward from top to bottom in a chamber, if an air flow perpendicular to the downward flow is applied to the middle, heavy powders subjected to high gravity will sink, while light powders subjected to low gravity will be moved to another space by the air flow and sorted.

[0003] However, this method has the disadvantage that it takes a long time to classify powders, and it is difficult to classify very small particles. Therefore, the present invention provides an apparatus that can easily separate powders in a short time by using an AC electric field. Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide a dielectric powder sorting device that can easily sort mixed dielectric powders by particle size, type, and shape by using the force q·E to make charged dielectric powders flow in an AC electric field. [Means for solving the problem]

[0005] FIG. 1 is a diagram showing the structure of a dielectric powder sorting device according to the present invention.

[0006] Referring to FIG. 1, a dielectric powder sorting device A for the purpose of the present invention includes a chamber, a lower electrode in the chamber, an upper electrode spaced apart from the lower electrode and disposed at the upper end of the chamber, a first separating layer disposed between the upper and lower electrodes in the chamber and not covering the upper and lower electrodes entirely, and a power supply applying means for applying an AC power supply to the lower and upper electrodes to apply an AC electric field between the lower and upper electrodes, and is characterized in that dielectric powder is positioned between the lower electrode and the first separating layer.

[0007] In the present invention, when an AC electric field is applied, a higher electric field is applied inside the dielectric powder layer than outside, making it easier for gas discharge to occur and charge the dielectric powder particles. The charged dielectric powder particles have the force to flow upward in the electric field within the chamber and can easily rise within the chamber. In this case, the force to flow upward can be applied to the dielectric powder particles differently depending on their size, density, shape, etc. As a result, the compositions of the dielectric powder accumulated on the first separation layer and the lower electrode after the AC electric field is applied can differ. The present invention is characterized by utilizing these differences to select the dielectric powder.

[0008] The upward flow of the dielectric powder can be controlled by controlling the magnitude of the voltage and AC frequency applied to the dielectric powder sorting device of the present invention. Therefore, the present invention can easily sort the dielectric powder by particle size, weight, density, dielectric constant, surface area, etc., using the sorting device. Specific details regarding this will be described below with reference to FIGS. 2 to 15 and examples.

[0009] In the present invention, when an AC electric field is applied, the characteristics of plasma generation inside and outside the fluid powder bed can be controlled by the voltage conditions provided by the gas supplied or supplied into the chamber. The gas supplied or supplied into the chamber when an AC electric field is applied may be air. In the case of flammable dielectric powder, an oxygen-free gas may be used. In the present invention, the gas supplied or supplied into the chamber when an AC electric field is applied is not particularly limited in type.

[0010] In the present invention, the term "dielectric powder" refers to an insulating powder that can be polarized positively and negatively in the direction of an electric field. The term may also refer to a material that has a net charge by storing excess charges in the form of electrons (-) or holes (+) on its surface through a charging step (e.g., plasma application by application of an electric field, photoelectric effect by irradiation with ultraviolet light, etc.) described below. In one embodiment, the dielectric powder may be a charged dielectric powder. Compared to uncharged dielectric powder, charged dielectric powder can have a net charge on its surface (excess charges stored in the powder in addition to the offset amount of positive and negative polarization charges), and therefore can more easily separate from the powder layer and have the ability to flow upward. Preferably, the dielectric powder may be a dielectric powder having a size of several nanometers to several thousand micrometers.

[0011] In one embodiment, a charging step of charging the dielectric powder in the chamber may be further performed before the generation of the AC electric field. For example, the charging step may be performed by applying an electric field for dielectrophoresis to the dielectric powder, irradiating it with UV light, or generating plasma.

[0012] In one embodiment, the charging step includes filling the chamber with a first gas, applying a voltage to generate plasma in the dielectric powder, and then filling the chamber with a second gas, where the first gas may be a gas having a lower discharge onset voltage than the second gas. For example, the charging step may be performed by filling the chamber with helium, applying a voltage to generate plasma in the dielectric powder to charge the dielectric powder, and then filling the chamber with air or SF6, which have a higher discharge onset voltage than helium.

[0013] In the present invention, the upper and lower electrodes can alternately function as a power electrode and a ground electrode. For example, when the lower electrode is a power electrode, the upper electrode can be a ground electrode, and when the lower electrode is a ground electrode, the upper electrode can be a power electrode.

[0014] The dielectric powder sorting device B for the purpose of the present invention is characterized in that it further includes a second separation layer located between the upper electrode and the lower electrode in the chamber, having a different height from the first separation layer, and not completely covering the upper electrode and the lower electrode. When an AC electric field is applied to the dielectric powder sorting device B, the dielectric powder has different upward flow forces depending on its size, density, surface area, etc., and can be piled up on the first separation layer and the second separation layer according to the sorting criteria.

[0015] In the present invention, the first and second separation layers may be dielectric. The distance between the first and second separation layers and the distance between the second separation layer and the upper electrode can be easily adjusted by the user. If the distance between the lower electrode and the first and second separation layers is too long, a problem occurs in that an unnecessarily high voltage must be applied. Therefore, the distance between the lower electrode and the first and second separation layers is preferably less than about 40 mm.

[0016] The dielectric powder sorting devices A and B of the present invention may further include a dielectric substrate laminated on the lower electrode. If a high voltage is applied between the upper and lower electrodes without a dielectric substrate, arc or spark discharge occurs, making it difficult to apply the desired high electric field, and charged particles flow only due to arc or spark discharge, making it impossible to impart a net charge to the powder particles. Therefore, the dielectric powder sorting device of the present invention preferably further includes a dielectric substrate laminated on the lower electrode.

[0017] The dielectric powder sorting device C for the purpose of the present invention includes a chamber, a lower electrode in the chamber, an upper electrode disposed between the upper end of the chamber body and the lower electrode so that the chamber can be divided into an upper space and a lower space, the upper electrode not completely covering the lower electrode, and a power supply means for applying an AC power supply to the lower electrode and the upper electrode so that an AC electric field is applied between the lower electrode and the upper electrode, and the dielectric powder is located between the lower electrode and the upper electrode.

[0018] The configuration of the dielectric powder sorting apparatus C is substantially the same as the configurations of the dielectric powder sorting apparatuses A and B described above with reference to FIG. 1, so a detailed description thereof will be omitted and differences will be mainly described below.

[0019] When an AC electric field is applied to the dielectric powder sorting device C, the dielectric powder accumulated on the upper electrode is no longer exposed to the electric field and does not flow, allowing it to be sorted according to the criteria, and powder that hits the lower surface of the upper electrode is dispersed and uniformly distributed as it repeatedly rises and falls due to the AC electric field, eventually accumulating on the upper electrode and being sorted. Typically, the frequency of the applied voltage is about several hundred Hz, so the powder rises and falls several hundred times per second, and the dielectric powder according to the sorting criteria accumulates on the upper electrode within several seconds, allowing the dielectric powder to be easily sorted within a short period of time.

[0020] The upper space formed in the chamber by the upper electrode can be any space having a distance that allows the powder to flow.

[0021] In the present invention, the dielectric powder sorting device C may further include a first dielectric substrate disposed above the upper electrode to form a space in which the powder can flow, and a second dielectric substrate stacked on the lower electrode. The first dielectric substrate prevents the rising powder from passing through the upper electrode and leaving the sorting device, and has the effect of isolating any gases within the sorting device from the outside air.

[0022] The apparatus may further include a dielectric substrate disposed on the upper end of the chamber and on the lower electrode together with the sorting devices A and B.

[0023] In the present invention, even if the dielectric powder flows upward and hits the upper end of the chamber and falls, it does not matter much in the present invention as long as it falls onto the first separation layer, the second separation layer, and the upper electrode provided as a filtering means and is separated.

[0024] In the present invention, the feeding of the dielectric powder and the recovery after sorting may be carried out by using means such as gas flow, mechanical vibration, and paddles. [Effects of the Invention]

[0025] According to the present invention, by controlling the voltage and frequency in consideration of the characteristics of each dielectric powder particle, it is possible to achieve the effect of sorting the mixed dielectric powder by particle size, weight, density, dielectric constant, or surface area within a few seconds to a few minutes. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a diagram showing the structure of a dielectric powder sorting device according to the present invention. [Figure 2] 2 is a diagram illustrating the principle of flow of dielectric powder through the dielectric powder sorting device of the present invention. [Figure 3]2 is a diagram illustrating an AC electric field applied through a dielectric powder separation device according to the present invention. [Figure 4] 1 is a diagram illustrating the behavior of dielectric powder that starts to flow in the dielectric powder sorting device of the present invention. [Figure 5] 1 is a diagram illustrating the behavior of dielectric powder particles in an AC electric field in the dielectric powder sorting device of the present invention. [Figure 6] 2 is a diagram for explaining flow modes FF, TM, and LF of dielectric powder in the dielectric powder sorting device of the present invention. [Figure 7] 1 is an image showing the flow modes FF, TM, and LF of powder under high AC voltage through the dielectric powder sorting device of the present invention. [Figure 8] 1 is a diagram showing a dielectric powder sorting device used in Examples 1 to 3 of the present invention. [Figure 9] 1 shows an image of the dielectric powder used in Example 1 of the present invention. [Figure 10] 1 shows an image of the dielectric powder selected through Example 1 of the present invention. [Figure 11] 1 shows an image of the dielectric powder used in Example 2 of the present invention. [Figure 12] 1 shows an image of the dielectric powder selected through Example 2 of the present invention. [Figure 13] 1 shows an image of the dielectric powder selected through Example 2 of the present invention. [Figure 14] 1 shows an image of the dielectric powder selected through Example 3 of the present invention. [Figure 15] 1 shows an image of the dielectric powder selected through Example 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The present invention may be modified in various ways and may have various forms, and specific embodiments are illustrated in the drawings and described in detail herein. However, it should be understood that this is not intended to limit the present invention to the particular disclosed form, but rather to include all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. Like reference numerals are used throughout the drawings to refer to like elements.

[0028] The terms used in this application are used only to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" are intended to specify the presence of features, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, steps, operations, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

[0030] FIG. 2 is a diagram showing the principle of flow of dielectric powder using the dielectric powder sorting device of the present invention.

[0031] Referring to FIG. 2, before the electric field is applied to the dielectric powder in the chamber, gravity F acts on the dielectric powder. g and the attractive force F between the dielectric powder d When an electric field is applied to the dielectric powder, the force of gravity F g and gravitational force F dThe electrostatic force F c At this time, the electrostatic force F applied to the dielectric powder is c is gravity F g and gravitational force F d If it is greater than the sum of (F c >F g +F d ), and the dielectric powder is subjected to electrostatic force F c This allows for upward flow.

[0032] The electrostatic force F c is the amount of charge q accumulated on the surface of the dielectric powder and the electric field E in the gas space above the dielectric powder layer. g can be determined by (F c =q·E g ), the attractive force F between the powder particles d is the electric field E applied in the dielectric powder layer p and is proportional to the dielectric constant ε of the dielectric powder (F d ∝E p , ε). At this time, the electric field E in the gas space above the dielectric powder layer g and the electric field E applied within the dielectric powder layer p Since the flow rate can be determined by the magnitude of the externally applied voltage and the shape of the electrodes, the present invention can easily separate the dielectric powder by controlling the force applied to the dielectric powder by adjusting the magnitude of the voltage using a dielectric powder separation device. In the present invention, factors that affect the flow of the dielectric powder other than the voltage include frequency and the amount of charge q accumulated on the surface of the dielectric powder.

[0033] In the present invention, the amount of charge q accumulated on the surface of the dielectric powder is the most important factor affecting the flow characteristics of the dielectric powder. The amount of charge q is most significantly affected by the surface area (powder particle size and shape) and density / dielectric constant (powder type) of the dielectric powder, and may also be affected by the type of surrounding gas. A light-weight dielectric powder with a large surface area flows very quickly in an external electric field, whereas a heavy-weight dielectric powder with a small surface area flows slowly in an external electric field. Furthermore, for dielectric powders of the same weight, the closer to a sphere (the smaller the surface area), the slower the flow, while the more deviant from a sphere (the larger the surface area, e.g., plate-like, rod-like, cylindrical, etc.), the faster the flow. In the present invention, the difference in the amount of charge of the dielectric powder can be utilized to sort the powders by particle size, shape, density, and dielectric constant.

[0034] FIG. 3 is a diagram for explaining the voltage applied through the dielectric powder separation device of the present invention.

[0035] Referring to FIG. 3, the voltage applied to the dielectric powder separation device of the present invention may be one AC high voltage selected from a sine wave, a square wave, a pulse wave, a triangular wave, a sawtooth wave, etc. Preferably, the voltage may be a square wave. A square wave voltage has a square waveform, and one cycle can be defined as a state in which the waveform changes once and then returns to its initial state. The time required to complete one cycle can be defined as a period T, and the number of cycles contained in one second can be defined as a frequency f.

[0036] In the dielectric powder sorting device of the present invention, the applied voltage V m is the voltage drop across the gas space, V g , voltage drop V across the dielectric powder layer p , the voltage drop across the dielectric substrate V d can be determined by the sum of (V m =V g +V p +2V d ) where the voltage drop across the gas space is V g and the voltage drop V across the dielectric powder layer pare the electric field E in the gas space, respectively. g and the electric field E applied within the dielectric powder layer p Each electric field affects the upward flow of the dielectric powder, so when a high voltage is applied, the upward flow distance of the dielectric powder can increase.

[0037] FIG. 4 is a diagram illustrating the behavior of dielectric powder that has begun to flow in the dielectric powder sorting device of the present invention.

[0038] 4, when an AC electric field is applied in the chamber of the sorting device of the present invention, a higher electric field can be applied inside the dielectric powder layer than outside the dielectric powder layer (i.e., the gas space where the dielectric powder can flow upward). As a result, the dielectric powder particles are provided with a charge amount q on their surfaces, and an electrostatic force F that allows the upward flow is generated. c The high electrostatic force F c The dielectric powder particles separated from the dielectric powder layer by the attractive force F between the dielectric powder particles d Electrostatic force F excluding c and gravity F g The dielectric powder is then only affected by the force F net can be expressed as the following mathematical formula 1.

[0039]

number

[0040] Referring to Equation 1, the force F that causes the dielectric powder separated from the dielectric powder layer to flow upward is net The acceleration a when a dielectric powder particle rises in an electric field can be derived from

[0041] At this time, the distance between the top of the dielectric powder layer and the bottom of the dielectric substrate, i.e., the maximum distance that the dielectric powder can move in the chamber, is d g If we define acceleration a and spatial distance d as g Through this, the dielectric powder is separated by the spatial distance d according to the following mathematical formula 2.g The time T when moving g can be derived.

[0042]

Number

[0043] In the present invention, when the dielectric powder moves a spatial distance d g The time T when moving g is less than T / 2 of the half cycle of the voltage, the dielectric powder hits the lower part of the dielectric substrate during the half cycle T / 2, and then falls back in the direction of the dielectric powder layer again. In the present invention, by utilizing such a technical principle, a first separation layer and a second separation layer are provided at appropriate positions between the upper electrode and the lower electrode in the chamber to screen the dielectric powder.

[0044] FIG. 5 is a drawing for explaining the behavior of dielectric powder particles in an alternating current electric field in the dielectric powder screening device of the present invention. (T / 2 < t g )

[0045] Referring to FIG. 5, when the time T when the dielectric powder moves a spatial distance d g is greater than T / 2 of the half cycle of the voltage, that is, when the spatial distance d g where the dielectric powder can flow is sufficiently long and the frequency of the voltage is high, the dielectric powder that has started to flow accelerates and rises by a distance d during the half cycle 0 - T / 2 of the voltage. When the polarity changes to the opposite, it decelerates and rises by a distance d' during the other half cycle T / 2 - T of the voltage. At this time, when the frequency condition of the voltage is d g < d + d', the dielectric powder will perform FF (Fully Fluidized) flow and reach the upper dielectric substrate completely. When d g = d + d', it will perform TM (Trap Mode) flow and almost touch the upper dielectric substrate. When d g > d + d', it will perform LF (Low Fluidized) flow. Such flow modes will be described with reference to FIG. 6. g > d + d', it will perform LF (Low Fluidized) flow. Such flow modes will be described with reference to FIG. 6.

[0046] FIG. 6 is a diagram for explaining flow modes FF, TM, and LF of dielectric powder in the dielectric powder screening device of the present invention.

[0047] Referring to Figure 6, the present invention utilizes a dielectric powder sorting device to have three flow modes: FF, TM, and LF. d+d' can increase with an externally applied voltage and an increase in the surface area of ​​the dielectric powder particles, while d+d' can decrease with an increase in the frequency of the externally applied voltage, the density of the powder particles, and the dielectric constant. Therefore, d g By providing a filtering means such as a first separation membrane and a second separation membrane at a position corresponding to the dielectric powder, and adjusting the magnitude of d+d' by controlling the magnitude and frequency of the externally applied voltage, the dielectric powder can be easily separated.

[0048] FIG. 7 is an image showing the flow modes FF, TM, and LF of powder under high AC voltage through the dielectric powder separator of the present invention.

[0049] 7 shows images of the dielectric powder separation device of the present invention performing FF, TM, and LF modes. In the FF mode, most of the dielectric powder flows upward from the lower electrode to the upper electrode, and in the TM mode, the dielectric powder flows upward to a shorter distance from the lower electrode than from the upper electrode compared to the FF mode. On the other hand, in the LF mode, the dielectric powder flows upward a very short distance.

[0050] The dielectric powder sorting device of the present invention will be described in more detail below through specific examples and comparative examples. However, the examples of the present invention are merely some embodiments of the present invention, and the scope of the present invention is not limited to the following examples. [Embodiment]

[0051] [Experimental equipment]

[0052] FIG. 8 is a diagram showing a dielectric powder sorting device used in Examples 1 to 3 of the present invention.

[0053] 8, the dielectric powder sorting device has a structure including a lower electrode, an alumina substrate having a thickness of about 1 mm on the lower electrode, and an upper electrode (GND) disposed between the upper end of the chamber body and the alumina substrate. The experiment was performed by placing the dielectric powder on the alumina substrate and the upper electrode.

[0054] [Experimental conditions]

[0055] The experimental conditions using the dielectric powder separator are shown in Table 1 below.

[0056] [Table 1]

[0057] Example 1

[0058] In Example 1 of the present invention, alumina ceramic powders for abrasives with different particle sizes were used. Specifically, a mixed powder of alumina ceramics (A100) with a particle size of 100 μm and alumina ceramics (A10) with a particle size of 10 μm was used, and the dielectric powder was sorted by particle size at a voltage of 20 kVpp and frequencies of 200 and 300 Hz.

[0059] FIG. 9 shows an image of the dielectric powder used in Example 1 of the present invention.

[0060] Referring to FIG. 9, it can be seen that the mixed powder used in Example 1 of the present invention is a homogeneous mixture of A100 and A10.

[0061] FIG. 10 shows an image of the dielectric powder selected according to Example 1 of the present invention.

[0062] Referring to Figure 10, when examining the dielectric powder after sorting under conditions of 20 kVpp and a frequency of 200 Hz, it can be seen that the mixed powder with a high specific gravity of A10 has accumulated on the upper electrode, while the mixed powder with a high specific gravity of A100 has accumulated on the alumina substrate. It can be seen that under conditions of 20 kVpp and a frequency of 200 Hz, the A100 and A10 particles are not completely separated. When examining the dielectric powder after sorting under conditions of a fixed voltage and a frequency of 300 Hz, it can be seen that only A10 powder has accumulated on the upper electrode.

[0063] The higher the frequency, the shorter the time it takes for powder particles to move upward or downward. When the same voltage is applied, when a low frequency (200 Hz) is applied, relatively immobile particles (heavy A100 particles with a small surface area to weight ratio) can also reach the separation layer, but when a high frequency (300 Hz) is applied, only relatively mobile particles (light A10 particles with a high surface area to weight ratio) can reach the separation layer and be separated. This demonstrates that the dielectric powder sorting device of the present invention can be used to easily separate powders of the same type.

[0064] Example 2 - Dielectric powder separation according to frequency

[0065] In Example 2 of the present invention, a mixed powder of alumina ceramics (A100) having a size of 100 μm and alumina balls (AB100) having a size of 100 μm was used to perform the separation of dielectric powder at a voltage of 20 kVpp and a frequency of 100 to 500 Hz.

[0066] FIG. 11 shows an image of the dielectric powder used in Example 2 of the present invention.

[0067] Referring to FIG. 11, it can be seen that the mixed powder used in Example 2 of the present invention is a uniform mixture of A100 and AB100, and in the case of AB100, it can be seen that the powder is approximately rectangular, but has a larger particle size deviation.

[0068] 12 and 13 show images of the dielectric powder selected according to Example 2 of the present invention.

[0069] 12 and 13, when sorting was performed under conditions of 20 kVpp and a frequency of 100 to 500 Hz, it was confirmed that, in the case of AB100, particles with larger particle diameters accumulated as the frequency decreased from 500 Hz to 100 Hz, and in the case of A100, particles with higher sphericity accumulated as the frequency decreased from 500 Hz to 100 Hz. After completing the separation experiment based on frequency, it was confirmed that, when powder P2 accumulated on the alumina substrate, AB100 powder with larger particle diameters accumulated.

[0070] This shows that the dielectric powder sorting device of the present invention can easily sort mixed powders having different surface areas by controlling the frequency.

[0071] Example 3 - Dielectric powder separation according to voltage magnitude

[0072] In Example 3 of the present invention, the same mixed powder as used in Example 2 was used to perform dielectric powder sorting at a frequency of 200 Hz, with the voltage varied in 2 kVpp increments within the range of 14 to 24 kVpp.

[0073] 14 and 15 show images of the dielectric powder selected according to Example 3 of the present invention.

[0074] Referring to Figures 14 and 15, when observing the dielectric powder P1 accumulated on the upper electrode, it can be seen that as the magnitude of the applied voltage increases, A100 particles with relatively uniform shape and AB100 particles with larger particle diameters accumulate. When observing the powder P2 accumulated on the alumina substrate after completing the separation experiment based on the magnitude of the voltage, it can be seen that AB100 powder with larger particle diameters accumulates.

[0075] It can be seen that the dielectric powder sorting device of the present invention can easily sort mixed powders having different surface areas by controlling the voltage.

[0076] Although the present invention has been described above with reference to preferred embodiments, it should be understood that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as defined in the claims.

Claims

1. a chamber; a bottom electrode within the chamber; an upper electrode disposed at an upper end of the chamber and spaced apart from the lower electrode; a first separation layer located between the upper electrode and the lower electrode in the chamber, the first separation layer not entirely covering the upper electrode and the lower electrode; and a power supply applying means for applying an AC power supply to the lower electrode and the upper electrode so that an AC electric field is applied between the lower electrode and the upper electrode; Including, a dielectric powder positioned between the bottom electrode and the first isolation layer; Dielectric powder sorting equipment.

2. 2. The dielectric powder sorting device according to claim 1, wherein the dielectric powder is a charged dielectric powder.

3. 2. The apparatus for separating dielectric powder according to claim 1, further comprising, before generating the AC electric field, performing a charging step of additionally charging the dielectric powder.

4. The dielectric powder sorting apparatus according to claim 3 , wherein the charging step includes applying an electric field for dielectrophoresis to the dielectric powder, irradiating the dielectric powder with UV light, or generating plasma.

5. The charging step includes filling the chamber with a first gas, applying a voltage to generate plasma in the dielectric powder, and then filling the chamber with a second gas; 4. The dielectric powder sorting device according to claim 3, wherein the first gas has a lower discharge start voltage than the second gas.

6. 2. The dielectric powder sorting device according to claim 1, wherein the dielectric powder is sorted by particle size, weight, density, dielectric constant, or surface area.

7. 7. The apparatus for sorting dielectric powder according to claim 6, wherein the magnitude of the voltage and the AC frequency of said power application means are controlled in accordance with the sorting criteria.

8. 2. The dielectric powder sorting device of claim 1, further comprising a second separation layer located between the upper electrode and the lower electrode in the chamber, the second separation layer having a different height than the first separation layer and not covering the entire upper electrode and the lower electrode.

9. The dielectric powder sorting device according to claim 1 , further comprising a dielectric substrate laminated on the lower electrode.

10. a chamber; a bottom electrode within the chamber; an upper electrode disposed between an upper end of the chamber body and the lower electrode so that the chamber can be divided into an upper space and a lower space, the upper electrode not entirely covering the lower electrode; and a power supply applying means for applying an AC power supply to the lower electrode and the upper electrode so that an AC electric field is applied between the lower electrode and the upper electrode; Including, The dielectric powder is positioned between the lower electrode and the upper electrode.

11. 11. The dielectric powder sorting device according to claim 10, wherein the dielectric powder is a charged dielectric powder.

12. The apparatus for separating dielectric powder according to claim 10, further comprising, before generating the AC electric field, performing a charging step of additionally charging the dielectric powder.

13. The dielectric powder sorting apparatus according to claim 12, wherein the charging step includes applying an electric field for dielectrophoresis to the dielectric powder, irradiating the dielectric powder with UV light, or generating plasma.

14. The charging step comprises: filling the chamber with a first gas and then applying a voltage to generate a plasma in the dielectric powder, and then filling the chamber with a second gas; The dielectric powder sorting device according to claim 12, wherein the first gas has a lower discharge start voltage than the second gas.

15. The dielectric powder sorting device according to claim 10, wherein the dielectric powder is sorted by particle size, weight, density, dielectric constant, or surface area.

16. 16. The device for sorting dielectric powder according to claim 15, wherein the magnitude of the voltage and the AC frequency of the power supply means are controlled in accordance with a sorting criterion.

17. The dielectric powder sorting device comprises: The apparatus for separating dielectric powder according to claim 10, further comprising a dielectric substrate disposed at an upper end of the chamber and spaced apart from the upper electrode in an upward direction.

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