Patent Grant
9220162
This application claims the benefit of Japanese Patent Application No. 2011-052233, filed on Mar. 9, 2011, Japanese Patent Application No. 2011-052234, filed on Mar. 9, 2011, and Japanese Patent Application No. 2011-093103, filed on Apr. 19, 2011, in the Japanese Patent Office, and Korean Patent Application No. 10-2011-0109432, filed on Oct. 25, 2011, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein in their entirety by reference.
1. Field
The present invention relates to a plasma generating apparatus and a plasma generating method.
2. Description of the Related Art
Recently, the demand for air quality controls in living environments, such as sterilization and deodorization, is increasing due to an increase in symptoms like atopy, asthma, and allergies and an increase in the risk of infections such as new influenza in the population. Furthermore, as living conditions become more and more affluent, the amount of stored food or chances of storing uneaten foods increases, and thus it has become more and more important to control environments in food storage devices, such as refrigerators.
Related arts for controlling air quality in living environments are generally related to physical controls, such as filters. Relatively large dusts and particles floating in the air may be trapped by using physical controls. Depending on the size of filter holes, germs or viruses may also be trapped by using physical controls. Furthermore, in a case of physical control unit having innumerable absorption sites, such as activated carbon, even malodor molecules may be trapped. However, to trap such malodor molecules, it is necessary to transmit all the air in a space to be controlled through a filter, thus resulting in an increase in the size of a device and maintenance costs for filter replacements. Furthermore, such physical control is ineffective against malodor molecules attached to something. Therefore, an example of means for sterilizing or deodorizing malodor molecules attached to something is to release chemically active species into a space to be sterilized or deodorized. For spraying chemicals, air fresheners, or deodorizers, it is necessary to prepare the chemically active species in advance, and thus it is inevitable to periodically restock such chemically active species. Recently, methods for generating plasma in the air and sterilizing or deodorizing by using chemically active species generated therefrom are becoming popular.
Methods for generating plasma in the air by using electric discharge and sterilizing or deodorizing by using ions or radicals (referred to hereinafter as “chemically active species”) generated therefrom may be categorized into two types:
(1) So-called passive plasma generating apparatuses which make germs or viruses floating in the air (referred to hereinafter as “floating germs”) or malodorous substances (referred to hereinafter as “malodors”) react with active species within a space with limited volume within the passive plasma generating apparatuses (e.g., Patent Reference 1).
(2) So-called active plasma generating apparatuses which spray active species generated by a plasma generating unit into a closed space with a volume larger than that in (1) above (e.g., living room, bathroom, interior of a vehicle, etc.), such that the active species in the art collide and react with floating germs or malodors in the art (e.g., Patent Reference 2).
Since a passive plasma generating apparatus of (1) generates plasma within a relatively small volume, active species are densely generated and thus highly effective sterilization and deodorization may be expected. However, since it is necessary to introduce floating germs or malodors into the passive plasma generating apparatus, the size of the plasma generating apparatus is relatively large. Furthermore, ozone may be easily generated as a by-product of the plasma generation, and thus, it is necessary to additionally install a filter for absorbing or decomposing ozone to prevent ozone from leaking out of the plasma generating apparatus.
On the other hand, an active plasma generating apparatus of (2) may be manufactured to have a relatively small size, and not only sterilization of floating germs and decomposition of malodors in the art, but also sterilization of germs attached to surfaces of clothing or household items (referred to hereinafter as “attached germs”) and decomposition of malodors attached to surfaces of clothing or household items may be expected. However, since active species spread into a closed space that is excessively large compared to the volume of the active surfaces of clothing or household items, the concentration of the active species decreases, and thus, a sterilization or deodorization effect may only be expected with active species having a relatively long lifespan. Therefore, little deodorization effect may be expected in a space with a high concentration of malodors (concentration that is about 10,000 times the concentration of active species).
As described above, a passive plasma generating apparatus is only effective against floating germs or malodors contained in the air flowing into the passive plasma generating apparatus, whereas an active plasma generating apparatus is practically only effective against floating germs, attached germs, and malodors with relatively low concentrations. In other words, a function of the related art is restricted only one of “sterilization and deodorization of floating germs” or “sterilization of floating germs and attached germs with relatively low concentrations and deodorization of floating and attached malodors with relatively low concentrations”.
Furthermore, electrodes constituting a plasma generating unit commonly employ porous dielectric layers, for example, at portions of the electrodes at which plasma is generated. Therefore, under conditions of high humidity, moisture absorption of a dielectric layer changes the electric properties of the dielectric layer, and thus the generation of plasma is diminished. Particularly, in an environment with a low temperature and changeable humidity, such as a refrigerator, dew may easily condense on the dielectric layers of the electrodes. As a result, plasma generation is stopped and the efficiencies of sterilization and deodorization deteriorate. Therefore, if high humidity is maintained in a refrigerator, it is difficult to maintain the efficiency of sterilization.
1. Japanese Patent Laid-Open Publication No. 2002-224211
2. Japanese Patent Laid-Open Publication No. 2003-79714
Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the invention.
The present embodiments provides a technique for simultaneously embodying sterilization and deodorization of attached germs by combining a passive mechanism for performing deodorization by using active species generated by generating plasma and an active mechanism for sterilizing attached germs by emitting the active species to outside of an apparatus for sterilization and deodorization by combining by increasing the amount of the generated active species and preventing dew condensation or moisture absorption at dielectric layers.
The present embodiments also provide a technique for improving the drying efficiency stabilizing the generated amount of active species by stabilizing plasma generation by improving the drying efficiency of dielectric layers.
According to an aspect, there is provided a plasma generating apparatus including a pair of electrodes, wherein a dielectric layer is arranged on at least one of surfaces of the electrodes facing each other, plasma discharge occurs as a predetermined voltage is applied to the electrodes, and a coating film is arranged on a surface of the dielectric layer.
A coating film is arranged on a surface of the dielectric layer, dew condensation and moisture attachment hardly occur on the dielectric layer, and thus deterioration of sterilizing efficiency under high humidity inside a refrigerator, for example, may be prevented. As a result, sterilizing efficiency may be maintained for an extended period of time. Furthermore, as fluid flowing holes are formed in portions respectively corresponding to electrodes to penetrate through the electrodes, amount of plasma generated at the corresponding fluid flowing holes may be maximized, and an area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of a plasma generating apparatus may be sufficiently high. Furthermore, the term ‘portions corresponding to electrodes’ means that fluid flowing holes formed in each of electrodes are located at substantially same locations when viewed from above. In other words, the fluid flowing holes are formed to have substantially same (x, y) coordinates at each of the electrodes when viewed in a z-axis direction in the rectangular coordinate system.
If the dielectric layer is formed using a thermal spraying method, the dielectric layer acquires a porous structure or a structure having fine protrusions and recessions, and thus the dielectric layer may be vulnerable to humidity. Therefore, effect of arranging a coating film becomes more significant.
For further reducing dew condensation and moisture attachment, the coating film may be water-repellent.
A thickness of the coating film may be from about 0.01 μm to about 100 μm. If the thickness of the coating film exceeds 100 μm, material properties of the dielectric layer are deteriorated. Furthermore, protrusions and recessions formed on a surface of the dielectric layer are buried, and thus plasma generating efficiency is lowered.
The plasma generating apparatus may further include a spacer, which is arranged between the pair of electrodes and has a thickness smaller than or equal to 500 μm. By forming the spacer, a distance between electrodes may be increased, and thus deodorizing reacting field may become larger. As a result, deodorizing efficiency may increase. Furthermore, since distance between electrodes increases as the spacer is formed, even if moisture is attached, only fine water drops are formed, and thus it is easy to drain the moisture. Here, methods for forming the spacer may include deposition, chemical vapor deposition (CVD), sputtering, or ion plating, a plating method, a thermal spraying method, a spray coating method, a spin coating method, or an application method.
A coating film may be arranged on a surface of the spacer to prevent dew condensation and moisture attachment at the spacer.
For efficient flow of fluid through fluid flowing holes to accelerate generation of active species and to improve deodorizing efficiency, an air-blowing mechanism for forcibly blows wind toward the fluid flowing holes may be further arranged.
Velocity of the wind which is blown by the air-blowing mechanism and passes through the fluid flowing holes may be from about 0.1 m/s to about 30 m/s.
To maximize a number of active species contained in a fluid passing through the fluid flowing holes and to minimize generated amount of ozone, voltages to the electrodes may be applied as pulses with peak values from about 100 V to about 5000 V and pulse widths from about 0.1 μ seconds to about 300 μ seconds.
According to another aspect, there is provided a plasma generating apparatus including a pair of electrodes, wherein a dielectric layer is arranged on at least one of surfaces of the electrodes facing each other, plasma discharge occurs as a predetermined voltage is applied at the electrodes, and a heating element is arranged at each of the electrodes or the dielectric layer.
In this case, since the heating elements are arranged in the electrodes or the dielectric layers, dew condensation and moisture attachment hardly occur and, even if dew condenses or moisture is attached, the dew or moisture may be dried. For example, the deterioration of sterilizing efficiency under high humidity inside a refrigerator may be prevented, and thus sterilizing efficiency may be maintained for an extended period of time. If dew condenses on a surface of a dielectric layer and plasma generation efficiency is deteriorated, the dielectric layer may be dried as the heating elements emit heat, and thus plasma generation may be restored. Furthermore, since the heating elements are arranged in an electrode or a dielectric layer and directly heat the electrode or the dielectric layer, the period of time for heating the electrode or the dielectric layer and energy for heating the electrode or the dielectric layer may be reduced as compared to heat radiation or indirect heating. Furthermore, since an electrode or a dielectric layer is heated by using the heating elements, reactive heat for deodorizing reaction may be supplied, and thus deodorizing reaction may be accelerated. Furthermore, by forming fluid flowing holes in portions corresponding to each of electrodes to penetrate through the electrodes, amount of plasma generated at the corresponding fluid flowing holes may be maximized, and thus the area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of the plasma generating apparatus may be sufficiently high.
Here, the heating element may be arranged in the electrode, may be arranged between the electrode and the dielectric layer, or may be arranged on a portion of surfaces of the dielectric layer.
According to another aspect, there is provided a plasma generating apparatus including a pair of electrodes; and a casing which supports the pair of electrodes, wherein a dielectric layer is arranged on at least one of surfaces of the electrodes facing each other, plasma discharge occurs as a predetermined voltage is applied to the electrodes, and a heating element for heating each of the electrodes or the dielectric layer is arranged at the casing.
Therefore, since the heating element is arranged at the casing and heats the electrodes and the dielectric layer, dew condensation and moisture attachment hardly occur and, even if dew condenses or moisture is attached, the dew or moisture may be removed.
A heating temperature of the heating element may be less than or equal to 150° C.
To prevent dew condensation and moisture attachment at a plasma generating location and to prevent deterioration of sterilizing efficiency and deodorizing efficiency by easily removing dews and moistures, a coating film may be arranged on a surface of the dielectric layer. Here, the coating film may be water-repellent. Furthermore, by using a water-repellent coating film, water-repellent malodor compounds may be easily absorbed by the coating film, and thus deodorizing efficiency may be improved.
A thickness of the coating film may be from about 0.01 μm to about 100 μm. Here, if the thickness of the coating film exceeds 100 μm, material properties of the dielectric layer are deteriorated. Furthermore, protrusions and recessions formed on a surface of the dielectric layer are buried, and thus plasma generating efficiency is lowered.
The plasma generating apparatus may further include a spacer, which is arranged between the pair of electrodes and has a thickness smaller than or equal to 500 μm. By forming the spacer, a distance between electrodes may be increased, and thus deodorizing reacting field may become larger. As a result, deodorizing efficiency may increase. Furthermore, since distance between electrodes increases as the spacer is formed, even if moisture is attached, only fine water drops are formed, and thus it is easy to drain the moisture. Here, methods for forming the spacer may include deposition, chemical vapor deposition (CVD), sputtering, or ion plating, a plating method, a thermal spraying method, a spray coating method, a spin coating method, or an application method.
For efficient flow of fluid through fluid flowing holes to accelerate generation of active species and to improve deodorizing efficiency, an air-blowing mechanism for forcibly blows wind toward the fluid flowing holes may be further arranged. Furthermore, evaporation of dew or attached moisture may be accelerated by forcibly blowing wind.
To maximize a number of active species contained in a fluid passing through the fluid flowing holes and to minimize generated amount of ozone, voltages to the electrodes may be applied as pulses with peak values from about 100 V to about 5000 V and pulse widths from about 0.1 μ seconds to about 300 μ seconds.
According to another aspect, there is provided a plasma generating apparatus including a pair of electrodes; and a casing which supports the pair of electrodes, wherein a dielectric layer is arranged on at least one of surfaces of the electrodes facing each other, plasma discharge occurs as a predetermined voltage is applied at the electrodes, fluid flowing holes are formed in each of the pair electrodes, a location of the fluid flowing holes corresponds to each other to penetrate through the electrodes, the casing opens at least a part of lateral openings formed between the pair of electrodes.
In this case, since the lateral openings formed between the pair of electrodes are at least partially opened by the casing, dew water formed in the pair of electrodes may be easily evaporated, and thus cumulative condensation of dew water in the pair of electrodes may be prevented. Therefore, the drying efficiency of the dielectric layers may be improved. As a result, generation of plasma may be stabilized, and thus the generated amount of active species may be stabilized.
Furthermore, if the casing completely covers the pair of lateral openings, dew water on a dielectric layer close to the fluid flowing holes may be dried, whereas drying efficiency of dew water on dielectric layers at other portions, such as around the pair of electrodes, is significantly low. According to the present invention, not only a dielectric layer close to the fluid flowing holes but also dielectric layers at other portions may be dried by opening the lateral openings of the electrodes.
Furthermore, by forming fluid flowing holes in portions corresponding to each of electrodes to penetrate through the electrodes, amount of plasma generated at the corresponding fluid flowing holes may be maximized, and thus the area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of the plasma generating apparatus may be sufficiently high.
The casing may include a wall unit facing the lateral opening, and a gas flow path may be formed between the lateral opening and the wall unit. Furthermore, by forming the wall unit facing the lateral opening, sparks, which are ignited by plasma, may be prevented from being propagated to outside.
The plasma generating apparatus may further include an air-blowing mechanism, which is arranged at leading ends or rear ends of the pair of electrodes to provide air to the lateral opening. In this case, since wind may be efficiently blown to the lateral openings, moisture may be easily drained via the lateral openings, and thus drying efficiency of dielectric layers may be improved. Furthermore, due to the air-blowing mechanism, fluid may efficiently flow through fluid flowing holes, and thus generation of active species may be accelerated and deodorizing efficiency may be improved. For example, in a household appliance, such as a refrigerator, the air-blowing mechanism may be efficiently operated with minimum energy by being linked with a sensor, such as a humidity sensor or a temperature sensor. Furthermore, since dew formation may be detected by determining whether applied voltage is lowered, amount of air to blow may be adjusted based on a result of the detection.
Air blown by the air-blowing mechanism may pass through the fluid flowing holes at a velocity from about 0.1 m/s to about 30 m/s.
In a case where a dielectric layer is formed using a thermal spraying method, fine protrusions and recessions are formed on a surface of the dielectric layer and, since fine protrusions and recessions face each other, drying efficiency is significantly deteriorated. According to the present invention, the deterioration of drying efficiency may be prevented by forming the lateral openings.
To prevent dew condensation and moisture attachment at a plasma generating location and to prevent deterioration of sterilizing efficiency and deodorizing efficiency by easily removing dews and moistures, a coating film may be arranged on a surface of the dielectric layer. Here, the coating film may be water-repellent. Furthermore, by using a water-repellent coating film, water-repellent malodor compounds may be easily absorbed by the coating film, and thus deodorizing efficiency may be improved.
A thickness of the coating film may be from about 0.01 μm to about 100 μm. Here, if the thickness of the coating film exceeds 100 μm, material properties of the dielectric layer are deteriorated. Furthermore, protrusions and recessions formed on a surface of the dielectric layer are buried, and thus plasma generating efficiency is lowered.
The plasma generating apparatus may further include a spacer, which is arranged between the pair of electrodes and has a thickness smaller than or equal to 500 μm. By forming the spacer, a distance between electrodes may be increased, and thus deodorizing reacting field may become larger. As a result, deodorizing efficiency may increase. Furthermore, since distance between electrodes increases as the spacer is formed, even if moisture is attached, only fine water drops are formed, and thus it is easy to drain the moisture. Here, methods for forming the spacer may include deposition, chemical vapor deposition (CVD), sputtering, or ion plating, a plating method, a thermal spraying method, a spray coating method, a spin coating method, or an application method.
To maximize a number of active species contained in a fluid passing through the fluid flowing holes and to minimize generated amount of ozone, voltages to the electrodes may be applied as pulses with peak values from about 100 V to about 5000 V and pulse widths from about 0.1 μ seconds to about 300 μ seconds.
According to another aspect, there is provided a method of generating plasma including preparing a pair of electrodes, wherein a dielectric layer is arranged on at least one of surfaces of the electrodes facing each other; and applying a predetermined voltage to the electrodes to occur plasma discharge, wherein a coating film is arranged on a surface of the dielectric layer.
By increasing generated amount of active species, sterilization of attached germs and deodorization may be embodied at the same time. Furthermore, by removing dews formed on or moistures attached to dielectric layers, deterioration of sterilizing efficiency may be prevented for an extended period of time.
Furthermore, by increasing generated amount of active species, sterilization of attached germs and deodorization may be embodied at the same time. Furthermore, by improving drying efficiency of dielectric layers, plasma generation may be stabilized, and thus generated amount of active species may be stabilized.
The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:
Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below to explain the present invention by referring to the figures.
Hereinafter, the present invention will be described in detail by explaining preferred embodiments of the invention with reference to the attached drawings.
A plasma generating apparatus 100 according to an embodiment of the present invention is used in a household appliance, such as a refrigerator, a laundry machine, a clothes dryer, a vacuum, an air conditioner, an air cleaner, etc., for deodorizing the air inside or outside a corresponding household appliance or sterilizing floating germs or attached germs inside or outside the corresponding household appliance.
Particularly, as shown in
Hereinafter, each of the components 2 through 5 will be described in detail with reference to the attached drawings.
As shown in
Here, the power supply 5 applies voltage to the plasma electrode unit 2 by applying voltages to the electrodes 21 and 22 as pulses with peak values from about 100 V to about 5000 V and pulse widths from about 0.1 μ seconds to about 300 μ seconds. As shown in
Furthermore, as shown in
Furthermore, as shown in
In detail, as viewed from above, the shapes of the fluid flowing holes 21b and 22b that are respectively formed in portions corresponding to the electrodes 21 and 22 are substantially circular (refer to
In this regard, as shown in
Furthermore, the total areas of the fluid flowing holes 21b and 22b respectively formed in the electrodes 21 and 22 are from 2% to 90% of the total areas of the electrodes 21 and 22. In detail, the fluid flowing hole 22b formed in the electrode 22 is formed to have a total area from 2% to 90% of the total area of the electrode 22. Furthermore, the fluid flowing hole 21b formed in the electrode 21 may be formed to have a total area from 2% to 90% of the total area of the electrode 21.
Furthermore, as shown in
The penetration hole 21c has an opening size that is 10 μm or more smaller than that of the fluid flowing hole 21b. The penetration hole 21c is formed by substituting a part of the fluid flowing holes 21b that are regularly formed, and the penetration hole 21c is formed around the fluid flowing hole 21b (refer to
An air-blowing mechanism 3 is arranged at a side of the electrode 22 of the plasma electrode unit 2 and includes an air-blowing fan for forcibly blowing air toward the fluid flowing holes 21b and 22 (the completely-opened portion) of the plasma electrode unit 2. In detail, air blown by the air-blowing mechanism 3 passes through the fluid flowing holes 21b and 22b at a velocity from about 0.1 m/s to about 30 m/s.
As shown in
However, in the present embodiment, as shown in
The coating films 23 are water-repellent and are formed of glass, fluororesin, silicon, diamond-like carbon (DLC), fluorine-containing DLC, SiO2, ZrO2, TiO2, SrO2, MgO, or a combination thereof. Furthermore, the coating films 23 are formed using a thin-film forming method, such as deposition, chemical vapor deposition (CVD), sputtering, or ion plating, a plating method, a thermal spraying method, a spray coating method, a spin coating method, or an application method to uniformly form the coating films 23 on the surfaces of the dielectric layers 21a and 22a.
Relationships between dew condensation cycles and ion number densities in the plasma generating apparatus 100 (the present invention) in which the coating films 23 are formed and a plasma generating apparatus (related art) in which no coating film is formed are shown in
A gap having a predetermined width is formed between the electrodes 21 and 22 due to spacers 24 that are formed of an insulation material. The spacers 24 are formed at various locations on edge portion of the electrodes 21 and 22, as shown in
The coating film 23 according to the present embodiment is formed after the dielectric layers 21a and 22a are formed using a thermal spraying method and the raw material units of the spacers 24 are formed on the dielectric layers 21a and 22a by using a thermal spraying method. Therefore, the spacers 24 are covered by the coating film 23, and thus dew condensation and moisture attachment to the spacers 24 may be prevented. Alternatively, the spacers 24 may be formed after the dielectric layers 21a and 22a and the coating film 23 are formed.
As the spacers 24 are arranged as described above, a distance between the electrodes 21 and 22 may be set as large as the thickness of the spacers 24. Therefore, as shown in
The plasma generating apparatus 100 configured as described above may be preferably used in a storage space of a refrigerator. As shown in
In the plasma generating apparatus 100 according to the embodiment as described above, the amount of plasma generated at the corresponding fluid flowing holes 21b and 22b may be maximized, and thus the area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of the plasma generating apparatus 100 may be sufficiently high. Furthermore, since the water-repellent coating film 23 is arranged on the surfaces of the dielectric layers 21a and 22a, dew condensation and moisture attachment hardly occur on the dielectric layers 21a and 22a. For example, the deterioration of sterilizing efficiency under high humidity inside a refrigerator may be prevented, and thus sterilizing efficiency may be maintained for an extended period of time.
The plasma generating apparatus 100 according to the present embodiment is substantially the same as the plasma generating apparatus 100 according to the previous embodiment of
Here, detailed descriptions of the plasma electrode unit 2, the air-blowing mechanism 3, the anti-explosion mechanism 4, the power supply 5, and the coating film 23 are same as those of the previous embodiment and thus are omitted.
The heating elements 6 heat the electrodes 21 and 22 and the dielectric layers 21a and 22a by using resistance heating, as shown in
The plasma generating apparatus 100 configured as described above may be preferably used in the storage space of a refrigerator. As shown in
In the plasma generating apparatus 100 according to the other embodiment as described above, the amount of plasma generated at the corresponding fluid flowing holes 21b and 22b may be maximized, and thus the area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of the plasma generating apparatus 100 may be sufficiently high. Furthermore, since the heating elements 6 are arranged in the electrodes 21 and 22 and heat the electrodes 21 and 22 and the dielectric layers 21a and 22a, dew condensation and moisture attachment hardly occur at the dielectric layers 21a and 22a, and, even if dew condenses or moisture is attached, the dew or moisture may be removed. For example, the deterioration of sterilizing efficiency under high humidity inside a refrigerator may be prevented, and thus sterilizing efficiency may be maintained for an extended period of time. Even if plasma generation efficiency is deteriorated due to dew condensation on surface of the dielectric layers 21a and 22a, the dielectric layers 21a and 22a may be dried as the heating elements 6 emit heat, and thus plasma generation may be restored. Furthermore, since the heating elements 6 are arranged in the electrodes 21 and 22 and directly heat the electrodes 21 and 22, the period of time for heating the dielectric layers 21a and 22a and energy for heating the dielectric layers 21a and 22a may be reduced.
Alternatively, according to another embodiment, deodorizing efficiency may be improved by forcing dew condensation. In other words, malodor compounds (e.g., water-soluble malodor compounds, such as trimethylamine) are absorbed and condensed in moisture of initially-condensed dew, and then the electrodes 21 and 22 are heated to generate high voltage plasma. Therefore, malodor compounds may be decomposed at a high efficiency.
The plasma generating apparatus 100 according to the present embodiment is substantially the same as the plasma generating apparatus 100 according to the previous embodiment of FIG. 11., except that, as shown in
A detailed descriptions of the plasma electrode unit 2, the air-blowing mechanism 3, the anti-explosion mechanism 4, the power supply 5, and the coating film 23 are same as of the previous embodiment and thus are omitted.
The protective cover 41, which is one of the components of the anti-explosion mechanism 4, may be detachably attached to the top surface and the bottom surface of the casing 25.
Furthermore, the casing 25 includes a wall unit 251 facing the lateral opening 2M, as shown in
In detail, penetration holes 25h is formed in two lengthwise sidewalls of the casing 25 penetrate the casing 25 from the top surface to the bottom surface, and form the gas flow path 25x. Furthermore, the wall unit 251 facing the lateral opening 2M is formed by sidewalls of the penetration holes 25h. As shown in
The plasma generating apparatus 100 configured as described above may be preferably used in the storage space of a refrigerator. As shown in
Confirming the drying efficiency of a plasma generating apparatus according to the present embodiment, the plasma generating apparatus was installed inside a refrigerator and the number of ions was measured. As experimental examples, a plasma generating apparatus (No. 1) in which lateral openings are not opened and a coating film and spacers are not formed, a plasma generating apparatus (No. 2) in which lateral openings are opened by the above-described penetration holes and a coating film and spacers are not formed, a plasma generating apparatus (No. 3) in which lateral openings are not opened and a coating film and spacers are formed, and a plasma generating apparatus (No. 4) in which lateral openings are opened by the above-described penetration holes and a coating film and spacers are formed were prepared. A result of measuring the number of ions of the plasma generating apparatuses (No. 1 through 4) is shown in Table 1 below.
From the result of the experiments shown in Table 1, it is clear that, if lateral openings are not opened in a pair of electrodes, the number of ions remarkably decreased as the days of operation in a refrigerator increased even if a coating film and spacers were formed (experimental examples No.1 and No. 3). On the contrary, as it is clear with the experimental example No. 2, the initial decrease in the number of ions due to dew condensation may be minimized by opening lateral openings. Furthermore, as it is clear with the experimental example No. 4, if opening lateral openings are combined with a coating film and spacers, the decrease in the number of ions may be prevented more effectively, and thus the plasma generating apparatus of the experimental example No. 4 may be stably used even in an environment like a refrigerator, in which humidity varies significantly and dew condensation may easily occur between a pair of electrodes.
In the plasma generating apparatus 100 according to an embodiment as described above, the amount of plasma generated at the corresponding fluid flowing holes 21b and 22b may be maximized, and thus the area by which the plasma and fluid contact each other may be maximized. Therefore, the generated amount of active species (ions and radicals) may be increased, and the effects of deodorizing by using the active species and sterilizing floating germs and attached germs by emitting the active species to outside of the plasma generating apparatus 100 may be sufficiently high. Furthermore, since the lateral openings 2M formed between the pair of electrodes 21 and 22 are at least partially opened by the casing 25, dew water formed in the pair of electrodes 21 and 22 may be easily evaporated, and thus cumulative condensation of dew water in the pair of electrodes 21 and 22 may be prevented. Therefore, the drying efficiency of the dielectric layers 21a and 22a may be improved. As a result, generation of plasma may be stabilized, and thus the generated amount of active species may be stabilized.
Furthermore, the present invention is not limited to the above embodiments.
For example, although a coating film is arranged on a dielectric layer of each electrode in the above embodiments, it is still effective even if a coating film is arranged on a dielectric layer of only one of the electrodes.
According to another embodiment, the locations of heating elements are not limited to inside the electrodes, as in the above embodiments. For example, as shown in
As shown in
The heating elements may be arranged on portions of surfaces of the dielectric layers 21a and 22a, such that a sufficient amount of plasma can be generated.
As shown in
As shown in
As shown in
Furthermore, in the casing 25 according to the above embodiment, aside from the gas flow path 25x having a vertically-arranged inlet and outlet, a gas flow path may be formed by forming a penetration hole 251a in the wall unit 251 facing the lateral opening 2M. In this case, the propagation of sparks may be prevented and a significant amount of air may be blown via the lateral opening 2M.
Furthermore, although the gas flow path 25x having a vertically-arranged inlet and outlet is formed in the casing 25 according to the above embodiment, a gas flow path 25y that is laterally opened in a sidewall of the casing 25 in correspondence to the lateral opening 2M may be formed, as shown in
As shown in
The heating element may be arranged in the casing 25 or the pair of electrodes 21 and 22. Therefore, in addition to the effect of accelerating evaporation of dew water by opening the lateral openings, evaporation of dew water may be further accelerated by the heating effect of the heating elements, and thus dielectric layers may be dried faster. Particularly, in a case of appliances, such as a refrigerator, heating elements may be efficiently operated with minimum energy by being linked with a sensor, such as a humidity sensor or a temperature sensor.
Although the plurality of the fluid flowing holes 21b in the electrode 21 have the same shape and the plurality of the fluid flowing holes 22b in the electrode 22 have the same shape in the above embodiments, the fluid flowing holes 21b or 22b may have different shapes.
Although all of the fluid flowing holes 21b in the electrode 21 are formed to be smaller than the plurality of fluid flowing holes 22b of the electrode 22 in the above embodiments, some of the fluid flowing holes 21b in the electrode 21 may be formed to be smaller than the fluid flowing holes 22b in the electrode 22, and the remaining fluid flowing holes 21b in the electrode 21 may be formed to be larger than the fluid flowing holes 22b in the electrode 22.
Although a penetration hole is formed in the electrode 21 or the electrode 22 in the above embodiments, penetration holes (semi-openings) may be formed in both of the electrodes 21 and 22.
The fluid flowing holes have the same cross-sectional shape in the above embodiments, the fluid flowing holes may have a tapered shape, a mortar-like shape, or a bow-like shape. In other words, the fluid flowing holes may be widened or narrowed from an opening to the other opening.
The fluid flowing holes may have any of various cross-sectional shapes, such as a circle, an ellipse, a rectangle, a straight slit, a concentric-circular slit, a wavy slit, a crescent, a comb, a honeycomb, or a star.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
Although a few embodiments have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-052233 | Mar 2011 | JP | national |
| 2011-052234 | Mar 2011 | JP | national |
| 2011-093103 | Apr 2011 | JP | national |
| 10-2011-0109432 | Oct 2011 | KR | national |
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| Number | Date | Country |
|---|---|---|
| 2001-210448 | Aug 2001 | JP |
| 2002-224211 | Aug 2002 | JP |
| 2003-79714 | Mar 2003 | JP |
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| 2006-120578 | May 2006 | JP |
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| Entry |
|---|
| Japanese Office Action issued Jun. 3, 2014 in corresponding Japanese Application No. JP2011-052233. |
| Number | Date | Country | |
|---|---|---|---|
| 20120229029 A1 | Sep 2012 | US |
