KR20130030368A

KR20130030368A - Plasma photocatalyst filter

Info

Publication number: KR20130030368A
Application number: KR1020110093786A
Authority: KR
Inventors: 김선주
Original assignee: 김선주
Priority date: 2011-09-19
Filing date: 2011-09-19
Publication date: 2013-03-27

Abstract

PURPOSE: A plasma photocatalyst filter is provided to have a simple structure, to have low manufacturing costs, to treat a large area and capacity, and to improve treating efficiency. CONSTITUTION: A plasma photocatalyst filter consists of an anode(100) and a cathode(200). The anode comprises a base and a conductive photocatalyst area(120). The conductive photocatalyst layer has a structure through which harmful gas can penetrate. The photocatalyst layer is spread on the outer surface of the base. The cathode faces and is spaced from the photocatalyst layer. The cathode has a structure through which harmful gas can penetrate. The plasma photocatalyst filter additionally comprises a gap-maintaining member which is a permeable insulator. The gap-maintaining member is arranged between the cathode and the anode. The anode and the cathode are respectively fixed to the both sides of the gap-maintaining member.

Description

Plasma Photocatalyst Filter {PLASMA PHOTOCATALYST FILTER}

The present invention relates to a plasma photocatalyst filter, and more particularly, the filter itself is used as a plasma generating electrode, and the photocatalyst is coated thereon to simultaneously perform plasma treatment, filtration and photocatalytic reaction, thereby maximizing treatment efficiency. It relates to a photocatalyst filter.

The technology related to plasma generation and treatment is widely used in various fields such as surface modification of materials, air purification, and water treatment in semiconductor processes, even though the outline is not explained. It is well known that there are hundreds of related patent applications. It is true.

Recently, as well-being has emerged as a social issue, interest in air cleaning is increasing, and the Ministry of Environment is also tightening regulations on indoor air purification of various buildings including industries.

For example, factories equipped with various manufacturing facilities, hospitals and laboratories that require cleanliness, offices, department stores, hotel lobbies, etc. where people come and go, homes, restaurants, etc., various dust, soot (SOx, NOx, etc.), Air is easily contaminated by VOCs, CFCs, bacteria, viruses, and fungi that live in cigarette smoke and dust, which causes various respiratory diseases, odors, and secondary infections caused by pathogens through contaminated air. The problem of harm to health has been raised, and numerous air sterilization and purification techniques have been proposed and disclosed to solve the problem.

In addition, in the field of water treatment, E. coli, viruses, bacteria, erythrocytes, T. bacteria, cholera bacteria, tuberculosis bacteria, Pseudomonas aeruginosa contained in drinking water, domestic water, and industrial water as well as waste water to prevent water pollution. Various types of treatment techniques have been disclosed in which plasma technology is applied to sterilization and purification of pathogens such as tetanus and tetanus.

As related technologies, Patent Publication No. 2000-0059884 'Air Purification Device', Patent Publication No. 2005-0004638 'Plasma Filter for Air Sterilization and Hazardous Gas Decomposition', and Publication Patent No. 2003-0092205 'Low Temperature Plasma and Photocatalyst Noxious gas treatment apparatus using filter ', Published Patent No. 2004-0085249' Air purification apparatus and method using a plasma filter having a three-dimensional cell structure ', Published Patent No. 2010-0123786,' Multiple fine plasma generating system ', Published patent 2009-0013061 'Plasma Deodorizer', Journal of the Korean Institute of Electrical Engineers Vol. 56, No. 1 (2007.01, Author: Shin Yoon Shin, Jae Duck) "A Study on Harmful Gas and Particle Removal Characteristics of Corona Discharge Plasma Filter in Combination with Photocatalyst", Korea Air Cleaning Association 2005.06, Vol. 69, Photocatalyst Special Edition, "Air-Cleaning System Using Low Temperature Plasma / Photocatalyst" (Professor, Yonsei Univ. Korean Patent Application No. 2001-34024, "High Efficient Hazardous Gas Purification System Using Microwaves," Korean Patent Application No. 2001-340, including papers on Byun Jung-hoon, Park Jae-hong and Yoon Ki-young). Korean Patent Application No. 2001-46294 "A sterilization and sterilization apparatus using high density plasma and its method, Korean Utility Application No. 2002-9234" Sterilization and cleanness " Composite lighting device having a function "; Korean Patent Application No. 2001-80359" Sewage sterilization apparatus using large-capacity high-efficiency ultraviolet rays ", Korean Utility Application No. 2002- A large number of prior arts have been disclosed, such as 5822 "High Efficiency Sterilization System Using Vibration Stirring Means" and Korean Application No. 2002-30525 "High Efficiency Ultraviolet Sterilization System Using Vortex".

Although the plasma processing technology has been usefully applied to various fields in various forms as described above, most of the application technologies related to air purification and cleaning are separate implementations of plasma single treatment, separate filtering technology, and separate photocatalyst technology. And even if they are integrated, when looking at the aspects of the technologies disclosed so far, the individual components are simply assembled into a single unit and modularized, so that large-capacity processing is difficult, and for large-capacity processing, a complex structure is required rather than a simple structure. There is a disadvantage that the cost of equipment increases exponentially.

In addition, almost all of the disclosed plasma processing techniques are focused on the development of technologies that enable efficient processing in a uniform space and confined spaces. Therefore, large-area processing through asymmetric plasma generation is repeated while generating and extinguishing plasma. Possible forms of technology development are underdeveloped.

In addition, the filtration technology focuses only on the development of filters such as electrostatic precipitating filters, HEPA filters, ULPA filters, activated carbon and carbon filters, prefilters, medium filters and manganese filters. There is very little association with each other, and most of them are implemented to only cover the air filtration function after the plasma treatment.

As an example of the more advanced technology, efforts have been made to increase the treatment effect by combining the low temperature plasma and the photocatalyst as described in the above-mentioned paper.

Low temperature plasma is a plasma generated through a kind of dielectric barrier discharge that discharges using a dielectric as an inclusion, unlike a plasma generated by corona discharge.

Such low-temperature plasma has the advantage of excellent processing efficiency because of high electron density and high electron energy. However, this low temperature plasma has a capacity limit that can be processed over a large area, and for the air purification and treatment, a separate filter system is used as in the conventional form. It still has the structural limitations it must have.

Another development focus of the prior art related to plasma processing is to improve the structure of the electrode to increase the plasma generation efficiency.

However, it has been confirmed that the disclosed techniques are almost exclusively limited to the shape of the electrodes such as spire, needle, reticulated, lattice, etc., and have not been disclosed for improvement of the electrode itself.

The present invention was created in view of the above-mentioned problems in the prior art, and was created to solve this problem. As a concept that does not exist in the past, a pair of electrodes that are opposed to each other is necessary for plasma generation, but is essential for air cleaning. By implementing the filter itself to be included directly into one electrode for plasma generation, it is possible to realize a single plasma-filter module that is actually integrated, rather than simply attaching two separate components, and activated by low temperature plasma. The main purpose of the present invention is to provide a plasma photocatalyst filter which is applied to the filter itself so that the function of the plasma-photocatalyst-filter can be realized as one single unit, thereby increasing processing efficiency and generating asymmetric plasma over a large area. There is this.

It is another object of the present invention to provide a plasma photocatalyst filter having a single electrode pair structure which is also integrated with each other around a member having a dielectric function.

The present invention is a means for achieving the above object, an electrode used in a plasma processing apparatus, a base having a structure through which harmful gas can pass to include a filter function, a conductive photocatalyst layer applied to the outer surface of the base An anode electrode; It provides a plasma photocatalyst filter comprising a cathode electrode disposed opposite to the photocatalyst layer constituting the anode electrode, the cathode electrode having a structure that can pass harmful gases.

In addition, the present invention is an electrode used in the plasma processing apparatus, an anode comprising a base having a structure through which harmful gas can pass to include a filter function, a conductive photocatalyst layer applied to the outer surface of the base; A cathode electrode disposed to face the photocatalyst layer constituting the anode electrode and having a structure through which harmful gas can pass; It is disposed between the anode electrode and the cathode electrode, the anode electrode and the cathode electrode is fixed to each side integrally attached to one surface, the gap maintaining member is a breathable insulator; provides a plasma photocatalyst filter comprising a.

In this case, in the plasma filter having the gap holding member, a sub-anode electrode is further provided at a distance from the anode electrode and electrically connected to the anode electrode, and the sub-anode electrode also has a structure that allows fluid to pass therethrough. There is a characteristic.

According to the present invention, since the plasma generating electrode and the filter are integrated, the structure is simple, the manufacturing cost is low, the large-capacity processing over a large area is easy, and the processing efficiency can be obtained.

1 is an exemplary schematic cross-sectional view showing the basic structure of a plasma photocatalyst filter according to the present invention.
2 is an exemplary cross-sectional view showing a modification of the plasma photocatalyst filter according to the present invention.
3 is an exemplary cross-sectional view showing another modified example of the plasma photocatalyst filter according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment]

Plasma photocatalyst filter according to the present invention, as the term appears, is ultimately a filter, but the main feature is that the filter itself constitutes an electrode to enable plasma generation.

In addition, the plasma photocatalyst filter according to the present invention is an air purifier or an air purifier or a part that is embedded in a unit or a housing that implements an air purification or clean system. Configuration only).

More specifically, as shown in Figure 1, the plasma photocatalyst filter according to the present invention is the cathode electrode and the cathode which is spaced apart from the anode electrode 100 at a predetermined distance, such as 3-5mm intervals Electrode 200.

In this case, the cathode electrode 200 may be any one of various types of cathode electrodes used in the plasma processing technology disclosed so far.

In other words, the cathode electrode 200 is not particularly specified, but may be a structure through which a fluid (harmful air) can pass well, such as a lattice type or a net type.

As a result, the cathode electrode 200 has a structure that does not affect the flow of the fluid, it is a story that is irrelevant to the needle, spire, thread, reticular.

Meanwhile, as shown in FIG. 1, the anode electrode 200 has a structure in which a conductive photocatalyst layer 120 is applied to a side of the base 110 to a predetermined thickness.

In this case, the anode electrode 200 also has to be a structure through which the fluid can pass through as well as the cathode electrode 100, but in addition to this should have a filter function has various types of filter structure disclosed in the prior Depending on the application, the pore size of the filter may vary.

In addition, the base 110 may be used regardless of an insulator or a non-insulator.

In addition, the photocatalyst layer 120 itself constitutes a kind of positive electrode when a voltage is applied. The photocatalyst layer 120 is configured to enable a photocatalytic activation reaction without a UV lamp by a low temperature plasma, and it is already 1998.5 "Photocatalyst and low temperature", which was developed by LG Electronics and certified by the Korea Industrial Technology Promotion Association, has been shown in the "Photocatalytic Plasma Air Purification Filter for Air Conditioning" technology, and also applied by NeoPotech Co., Ltd. and evaluated by the Korea Industrial Technology Association. It is also shown in the technology for purifying odor gas using plasma, and is also shown in the patent technology disclosed in the related patent publication “No. 2010-0125855“ Ozone Water Supply Device Using Photocatalyst and Low Temperature Plasma ”.

Nevertheless, if the efficiency is low, it is possible to extend the lifespan and to use ultraviolet light emitting diodes (UV-LEDs) suitable for high-capacity processing as photocatalytic activation means.

In this case, as the photocatalyst for implementing the photocatalyst layer 120, any one selected from TiO ₂ , SiO ₂ , ZnO, and WO ₃ may be used, which has high dual activity, low cost, harmless to the human body, and excellent chemical stability. Particular preference is given to using ₂ .

As such, since the photocatalyst layer 120 is conductive in itself (mainly a semiconductor), the photocatalyst layer 120 may be placed in a state where it can be energized when a voltage is applied.

Accordingly, the photocatalyst layer 120 constitutes a positive electrode to which an anode is applied, and a cathode electrode 200 which is a negative electrode spaced apart from the anode electrode 100, which is a positive electrode, at a predetermined interval, for example, 3-5 mm apart. The discharge occurs between and) to induce a high-density plasma to be generated.

That is, the plasma photocatalyst filter according to the first embodiment of the present invention does not have a structure in which a dielectric is interposed between the anode electrode 100 and the cathode electrode 200, but discharges a kind of corona discharge apart from each other with a gap (gap) therebetween. To induce a plasma.

Here, the thickness of the photocatalyst layer 120 applied to the base 110 does not need to be limited, which is sufficient to realize and find a suitable thickness to have a degree necessary for plasma generation through repeated experiments. Because.

Therefore, the low temperature plasma generated between the anode electrode 100 and the cathode electrode 200 decomposes nitrogen oxides, sulfur oxides, volatile organic compounds, and the like.

In addition, the low temperature plasma excites the photocatalyst of the photocatalytic layer 120 to activate the photocatalytic oxide, and generates photo radicals to process the harmful gas by photocatalytic oxidation according to the activation of the photocatalyst.

Here, the photocatalytic oxidation reaction is a well-known matter, so it is not necessary to explain it. However, in order to clarify the process of treating harmful gases, when the photocatalyst is activated, the photocatalyst is activated in VB (Valence Band) and CB (Conduction Band), respectively. a hole (h ⁺⁾ and the excited electrons (e ^{-) -} formed by hydroxyl radicals by their high reactivity are formed and these and a hydroxyl radical (OH) and active oxygen (O ₂₎ in the air, water and oxygen to react Refers to a strong oxidation reaction and free radicals to reduce organic matter.

For example, oxidative reaction of organic compounds, waste treatment of organic acids or cyanide, decomposition of chlorinated hydrocarbons, and the like, when photons are adsorbed on the semiconductor surface, the light energy hv is the semiconductor bond energy. If it is greater than or equal to, electrons are emitted from the valence band of the semiconductor.

^{hv + solid ----- → h + +} e -

In this case, light rays in the near ultraviolet region are required, and in the case of the n-type semiconductor, the potential of the charged portion in the semiconductor is changed to move the photon holes to the surface. When TiO ₂ particles are irradiated with ultraviolet rays, the following reactions occur.

TiO ₂ ------- → TiO ₂ (e ^- _cb + h ⁺ _vb )

The generated electrons and photon holes move to traps on the surface,

e ^- _cb ------- → e ^- _tr

h ^- _vb ------- → h ⁺ _tr

At this time, when oxygen is present on the surface of the photocatalyst, a superoxide anion radical is generated by acting as a reducing agent in the surface pores.

e ^- _tr + O ₂ → O ₂ ------ ^-

On the other hand, the negative ions adsorbed on the surface react with the photon holes to form OH radicals.

^{_{^{e - tr + OH - ------ →}}} OH

Photon holes also oxidize water or react with hydroxide ions on the particle surface to form OH radicals.

h ^- _tr + H ₂ O ------ → OH + H ⁺

Mechanism of photocatalytic oxidation reactions electron and electron hole is H ₂ O, OH ^- oxidation with ^- OH radical to participate in the reduction reaction is electron hole is H ₂ O, OH -, oxidation with an adsorbent material, such as organic compounds, O ₂ Produced by the reaction.

E is O ₂ to participate in the reduction reaction of the adsorbed oxygen ^- to generate, wherein O ₂ ^- is reacted with H ₂ O sometimes generate OH radicals. The OH radical is the most important oxidant in the photocatalytic oxidation of organic matter.

As such, charge-holes form in the semiconductor, where both materials move to a surface that can recombine or react with adsorbents. The holes or electrons formed through this process will disappear through one of the following three reactions.

First, the photocatalytic reaction is as follows.

Aad (adsorbent A) + h ⁺ → (Aad) ⁺

Bad (adsorbent _{^{B) + e cb - → (}} Bad) -

(Aad) ⁺ + (Bad) ^- → product

In this reaction, the generated holes and electrons finally recombine, but the light energy already absorbed is used to supply the activation energy of the reaction.

The semiconductor used in the reaction remains unchanged.

Second is the change response of the lattice.

h ⁺ + grid → (grid) ⁺

(Grid) ⁺ → lattice reaction products

In the case of the 'grid change reaction', the semiconductor used in the reaction changes as the reaction proceeds. The semiconductor used in the reaction remains unchanged. In fact, sulfide-based semiconductors such as CdS easily cause photocorrosion in aqueous solution by irradiation of light.

Third is the recombination reaction of electrons and holes.

h ^{+ +} e _cb ^- → heat

The recombination reaction between electrons and holes is a case where the generated holes and electrons recombine directly without participating in the photocatalytic oxidation reaction.

Since organic matter is decomposed through such a process, in the present invention, since low temperature plasma, photocatalysis by photocatalyst, and filtering are simultaneously performed, the separate components are connected to each other as if they were configured as one module. It will be appreciated that other new structures have been implemented and that this will maximize the processing efficiency.

[Second Embodiment]

The second embodiment according to the present invention has the conceptual structure as shown in FIG.

As shown in FIG. 2, the plasma photocatalyst filter according to the second embodiment of the present invention has a structure in which the anode electrode 100 and the cathode electrode 200 are completely integrated with each other, and the gap maintaining member 300 interposed therebetween. It further includes.

In this case, the anode electrode 100 and the cathode electrode 200 have the same structure as in the first embodiment described above, and the gap retaining member 300 is an insulator having ventilation.

The anode electrode 100 and the cathode electrode 200 are integrally fixed to both surfaces of the gap maintaining member 300.

Accordingly, the electrode itself can be integrated into a single assembly, so assembly and installation and maintenance are easy, and the gap is fixed and maintained in a predetermined state, so that an electrode assembly having various gaps can be made according to the design according to the design at the time of initial production. Has

In particular, the plasma photocatalyst filter according to the second embodiment of the present invention is suitable for a dielectric barrier discharge method capable of generating low-temperature plasma, and above all, a large-capacity treatment for a large area when the flow of fluid is low It is possible and the processing efficiency can be maximized.

In addition, in the second embodiment of the present invention, the gap holding member 300 serving as the dielectric is disposed to face each other, so that a high concentration of avalanche due to micro discharge is generated through charge-up due to the dielectric barrier. To induce it to occur.

At this time, electron avalanche is the electron in the material is accelerated by the electric field and collides with atoms or molecules of the material to ionize them to make secondary electrons, the original electron and secondary electrons are accelerated again by the electric field Collisions create tertiary electrons, and this process is repeated to increase the number of electrons exponentially.

In other words, in the present invention, when charge accumulation occurs in the gap maintaining member 300 such as a nonwoven fabric serving as a dielectric, a rapid discharge occurs after a certain instant of instantaneous discharge, thereby rapidly raising the processing efficiency.

[Third Embodiment]

The third embodiment according to the present invention has the conceptual structure as shown in FIG.

As shown in FIG. 3, in the plasma photocatalyst filter according to the third embodiment of the present invention, the anode electrode 100 and the cathode electrode 200 are completely integrated with each other with the gap maintaining member 300 interposed therebetween. It has the same structure as the example, but further includes a sub-anode electrode 140.

At this time, the sub-anode electrode 140 is connected to the anode electrode 100, the combined amount of the two and the amount applied to the cathode electrode 200 should be the same amount.

However, depending on the control state, the amount of application to be distributed to the sub-anode electrode 140 may be adjusted differently.

For example, when an application amount of "100" is applied to the cathode electrode 200, "90" may be applied to the anode electrode 100 and "10" may be applied to the sub-anode electrode 140.

When the sub-anode electrode 140 is disposed at a certain distance from the anode electrode 100, an electric field is formed between them, thereby increasing acceleration due to an avalanche to easily and efficiently handle harmful gas over a large area. It becomes possible.

At this time, it is obvious that the sub-anode electrode 140 must also have a structure that allows the fluid to pass therethrough.

In addition, of course, the sub-anode electrode 140 may be extended in the form of a plurality of sub-anode electrodes.

In addition, if necessary, a plurality of conventional filters may be further interposed in the space between the anode electrode 100 and the sub-anode electrode 140.

In addition, the structure of this third embodiment can be applied to the above-described first embodiment as it is.

By inverting the existing plasma electrode concept and establishing a new concept, high-efficiency processing that has not been achieved is possible, and large-scale processing over a large area can be easily implemented, but manufacturing cost is low, and installation and management are easy. First of all, the asymmetrical plasma generation and the generation and dissipation of ions and electrons can be repeated to rapidly process high density.

100: anode electrode 110: base
120: photocatalytic layer 140: sub-anode electrode
200: cathode electrode 300: gap holding member

Claims

As an electrode used in a plasma processing apparatus,
An anode comprising a base having a structure through which harmful gas can pass to include a filter function, and a conductive photocatalyst layer applied to an outer surface of the base;
And a cathode electrode disposed to face the photocatalyst layer constituting the anode and spaced apart from each other, the cathode electrode having a structure through which harmful gas can pass.

As an electrode used in a plasma processing apparatus,
An anode comprising a base having a structure through which harmful gas can pass to include a filter function, and a conductive photocatalyst layer applied to an outer surface of the base;
A cathode electrode disposed to face the photocatalyst layer constituting the anode electrode and having a structure through which harmful gas can pass;
And a gap retaining member disposed between the anode electrode and the cathode electrode, wherein the gap retaining member is a breathable insulator in which the anode electrode and the cathode electrode are integrally attached and fixed to one surface of each surface.

The method according to claim 1 or 2,
And a sub anode electrode electrically connected to the anode electrode at a distance from the anode electrode, wherein the sub anode electrode also has a structure that allows fluid to pass therethrough.