Title of Invention: APPARATUS FOR COLLECTING SUSPENDED PARTICLE

Technical Field

[1] The present invention relates to an apparatus collecting floating dusts, and more particularly, to an apparatus collecting floating dusts, which is easy to be maintained, has improved safety, and has high efficiency.

[2]

Background Art

[3] Generally, an apparatus collecting floating dusts, which includes an emitter and a collector, that is, a dust collecting electrode, applies high voltages different from each other to the emitter and the collector artificially and discharges electricity to electrify particles of floating dusts in such a way that the electrified particles are collected by the emitter and the collector, which have a different polarity from each other, using electrical force.

[4] Such apparatus may be used to purify the air in a clean room for a process of manufacturing semiconductors or liquid crystal displays (LCDs) or environmental pollution in the air.

[5] On the other hand, as an example of such collecting apparatus, there is an apparatus collecting floating dusts, which includes an emitter electrode in the shape of a wire and a collector electrode in the shape of wings, opposite to each other. However, the collector electrode in the shape of wings has a great size since electrified particles pass therethrough and are collected. Also, since it is difficult to remove particles collected thereto due to an installation structure of the collector electrode in the shape of wings, it is difficult to maintain the apparatus. That is, when washing the apparatus by injecting a cleaning fluid, it is difficult to perform a detailed cleaning, thereby deteriorating collecting performance when reusing the same.

[6] Also, in Japanese Patent Laid-Open Publication No. 2008-18340, there is disclosed a structure in which electrodes in the shape of wires, to which a positive high voltage and a negative high voltage are alternately applied. However, since adhesives are applied to the surface of such electrodes in the shape of wires to collect floating dusts, it is difficult to clean the same. Accordingly, when there is required to exchange an electrode after using once, it is difficult to reuse the same. Also, while using an electrode of high voltage, there is not provided a safety system. Accordingly, there is not provided stable operation and there exists a danger to use.

[7] Disclosure of Invention

Technical Problem

[8] The present invention provides an apparatus collecting floating dusts, which is easy to be maintained, has improved safety, and has high efficiency.

[9]

Solution to Problem

[10] According to an aspect of the present invention, there is provided an apparatus collecting floating dusts, the apparatus including: a housing including a frame forming a hollow empty space and an electronic component part below the empty space in the frame; an emitter electrode part including a frame detachably installed inside the frame of the housing and including a plurality of rod electrodes arranged transverse to the empty space; and a collector electrode part including a plate electrode installed opposite to the emitter electrode part and including a frame detachably installed inside the frame of the housing, wherein the plate electrode of the collector electrode part includes a plurality of holes through which air flows, thereby forming an ionic wind and collecting floating dusts in the air.

[11] A direction of arranged holes formed on the plate electrode is opposite to a direction of respective arranged rod electrodes. The rod electrodes and the plate electrode are formed of a conductive material and connected to a power supply via a high voltage transformer provided inside the electronic component part, in which the rod electrodes and the plate electrode are electrified by supplying a power of an opposite polarity from each other.

[12] On the electronic component part inside the frame of the housing, there are provided elastic pin connectors elastically protruded upwards to connect a power supply to power connection parts formed on respective bottom surfaces of the emitter electrode part and the collector electrode part.

[13] The frame of the emitter electrode part and the frame of the collector electrode part include a hook coupled with a bottom of a protrusion formed on the housing, respectively.

[14] The frame of the emitter electrode and the frame of the collector electrode part include a pivotal handle hinge-connected thereto, respectively.

[15] A front and a rear of the housing are detachably coupled with protection plates formed of an insulating material and including a plurality of through holes, respectively.

[16] The apparatus further includes a safety element including first and second sensors provided on a front and a rear of the electronic component part, respectively, and sensing whether the protection plates are coupled therewith, to selectively cut off supplying a power to the emitter electrode part and the collector electrode part depending on whether the protection plates are coupled therewith or not.

[17] A plurality of the apparatuses are installed in top and bottom, right and left of a plurality of containing parts and form one face of an assembly of the plurality of the apparatuses to intensively collect floating dusts in an object space of purifying. Moving wheels are provided on a bottom of a frame of the assembly of the plurality of the apparatuses.

[18] According to another aspect of the present invention, there is provided an apparatus collecting floating dusts, the apparatus including: a housing including a frame forming a hollow empty space and an emitter electrode part and a collector electrode part disposed therein opposite to each other and detachably provided inside the frame; a plurality of protection plates detachably coupled with a front and a rear of the housing and formed of an insulating material where a plurality of through holes are formed to allow air to pass therethrough; and a safety element selectively cutting off supplying a power to the emitter electrode part and the collector electrode part depending on whether the protection plates are coupled therewith or not.

[19] The safety element includes: first and second sensors provided on a front and a rear of an electronic component part formed below the empty space inside the housing and sensing whether the protection plates are coupled therewith or not; and a third sensor provided on a top of the electronic component part below the empty space and sensing whether one of the emitter electrode part and the collector electrode part is detached or not.

[20] The first, second, and third sensors are button type switches pressurized while an object of sensing is coupled therewith.

[21] The safety element further includes a selection switch on the front of the electronic component part, the selection switch turned on and off to allow the first, second and third sensors form a line in series and to selectively supply a power to both ends of the line in series of the first and second sensors, thereby determining whether a safety mode is operated.

[22] A hook with a groove slanting downwards to be coupled with a protrusion provided in an inner circumferential surface of the frame of the housing is provided on an edge of the protection plates, thereby allowing the protection plates to be pressurized and closely attached to an outer surface of the housing due to self-gravity.

[23] According to still another aspect of the present invention, there is provided an apparatus collecting floating dusts, the apparatus including: a housing including a frame forming a hollow empty space; a collector electrode part detachably provided inside the frame of the housing and including a plate electrode collecting floating dusts in the air; and first and second emitter electrode parts detachably provided inside the frame of the housing and disposed opposite to and separated from a front and a rear of the plate electrode and formed of frames including a plurality of first and second rod electrodes forming an ionic wind of peripheral air, respectively.

[24] The first and second rod electrodes and the plate electrode are formed of a conductive material and connected to a power supply via a high voltage transformer provided inside the housing, in which a power of the same polarity is supplied to the first rod electrodes and the second rod electrodes and a power of an opposite polarity to that of the power supplied to the first and second rod electrodes is supplied to the plate electrode to electrify the same.

[25]

Advantageous Effects of Invention

[26] The present invention provides an apparatus collecting floating dusts, the apparatus capable of providing effects as follows.

[27] First, a plate electrode where a plurality of holes are formed is separated from and opposite to rod electrodes, thereby improving the performance of collecting floating dusts in addition to providing a compact size. Via this, it is possible to form various effective and compatible arrangements in a limited space in a clean room.

[28] Second, arrangement configurations of the plurality of holes formed on the plate electrode and the rod electrodes are variable, thereby providing a degree of freedom of design to correspond to various field applications. A collector electrode part including the plate electrode and an emitter electrode part including the rod electrodes may be separated to be easily and tidily cleaned using cleaning fluid, thereby notably improving maintenance characteristics.

[29] Third, due to a safety element sensing whether protection plates provided on a front and a rear of an empty space of the housing are assembled therewith and cutting off supplying a power when the protection plates are not assembled therewith, it is possible to provide stable operation of a product and notably improving safety of a user.

[30] Fourth, when rod electrodes are provided on a front and a rear of the plate electrode, respectively, an ionic wind along both of the front and the rear of the plate electrode are generated and both of them are used for collecting dusts, thereby notably improving collecting efficiency.

[31]

Brief Description of Drawings

[32] FIG. 1 is an external perspective view illustrating an apparatus collecting floating dusts according to an embodiment of the present invention;

[33] FIG. 2 is a front external perspective view illustrating a housing employed to the apparatus of FIG. 1 ;

[34] FIG. 3 is a rear external perspective view illustrating the housing of FIG. 2;

[35] FIG. 4 is an exploded perspective view illustrating the apparatus of FIG. 1;

[36] FIG. 5 is a view illustrating an interaction between a plate electrode and rod electrodes employed to the apparatus of FIG. 1 ;

[37] FIG. 6 is a top view illustrating a configuration of the arrangement of the plate electrode and the rod electrodes;

[38] FIG. 7 is a circuit diagram illustrating a safety element of the apparatus;

[39] FIG. 8 is a perspective view illustrating an example of using the apparatus of FIG. 1 ;

[40] FIG. 9 is a perspective view illustrating another example of using the apparatus of

FIG. 1;

[41] FIG. 10 is an exploded perspective view illustrating a polarity configuration of an apparatus collecting floating dusts according to another embodiment of the present invention; and

[42] FIG. 11 is a cross-sectional view illustrating main parts of the apparatus of FIG. 10.

[43]

Best Mode for Carrying out the Invention

[44] Hereinafter, the preferable embodiments of the present invention will be described in detail with reference to the attached drawings.

[45] FIG. 1 is an external perspective view illustrating an apparatus 10 collecting floating dusts according to an embodiment of the present invention. FIG. 2 is a front external perspective view illustrating a housing 100 of the apparatus 10 of FIG. 1. FIG. 3 is a rear external perspective view illustrating the housing 100.

[46] Referring to FIGS. 1 to 3, the apparatus 10 includes a housing forming a frame including an empty space 101 forming a hollow therein and an electronic component part 110 including various electronic components such as a printed circuit board (PCB), located below the empty space 101. In this case, the housing 100 may be formed of aluminum to be electrically protected. On one side of the housing 100, there are provided a power input terminal 106 and a power output terminal 107. Also, on one side of a front of the housing 100, there are provided a main power supply switch 102 and a selection switch 103 capable of selecting whether to operate a safe mode in which a power supply to an emitter electrode part 120 (shown in FIG. 4) and a collector electrode part 130 (shown in FIG. 4) is selectively cut off according to whether protection plates 160 are coupled with the front and a rear of the housing 100, respectively.

[47] Also, inside the electronic component part 110, the emitter electrode par 120 and the collector electrode part 130 detachably installed inside the frame of the housing 100 are assembled in such a way that a power is selectively supplied and converted and a high voltage is changed to purify the air by collecting floating dusts in the air in addition to providing safety to a user while supplying a power of a high voltage.

[48] FIG. 4 is an exploded perspective view illustrating the apparatus 10.

[49] Referring to FIG. 4, the apparatus 10 includes the housing 100, the emitter electrode part 120, and the collector electrode part 130.

[50] The emitter electrode part 120 is detachably installed inside the frame of the housing

100 and includes a frame 123 including a plurality of rod electrodes 121 transverse to the empty space 101. In this case, the rod electrodes 121 are separated from one another at a predetermined interval and may be formed of a conductive material such as stainless steel and a conductive high polymer material and electrified to a negative polarity by supplying a negative power passing through a high voltage transformer provided in the electronic component part 110 inside the housing 100. The rod electrodes 121 may be formed in the shape of a wire but not limited thereto. For example, the rod electrodes 121 may be formed in the shape of a hollow cylinder.

[51] Also, the collector electrode part 130 is detachably installed inside the frame of the housing 100 and includes a plate electrode 131 installed opposite to the arrangement of the rod electrodes 121. That is, a surface formed by the plurality of rod electrodes 121 is parallel to and separated from at a predetermined interval the plate electrode 131. In this case, the plate electrode 131 is formed by forming a plurality of holes 132 in such a way that peripheral air moves via the holes 132 to form an ionic wind. The plate electrode 131 may be formed of a conductive material such as stainless steel and a conductive high polymer material. An outline thereof may be surrounded by a frame 133. The shape of the hole 132 may be a circle whose diameter is about 10 mm but not limited thereto.

[52] A positive power may be supplied to the plate electrode 131 via a high voltage transformer provided inside the electronic component part 110 of the housing and electrifying the plate electrode 131 as a positive polarity. -5kV of power may be supplied to the rod electrodes 121 and +5kV of power may be supplied to the plate electrode.

[53] That is, to the rod electrodes and the plate electrode, powers of mutually opposite polarities are supplied to electrifying the same. As described above, when powers of mutually opposite polarities are supplied, a negative power may be supplied to the plate electrode 131 and a positive power may be supplied to the rod electrodes 121. Hereinafter, it will be described based on an example described above in which a positive power is supplied to the plate electrode 131 and a negative power is supplied to the rod electrodes 121.

[54] Via this, a constant voltage is formed between the rod electrodes 121 and the plate electrode 131 and there is formed an ionic wind in which the air around the rod electrodes 121 heads for the plate electrode 131 due to Coulomb force.

[55] In this case, due to a potential difference of 1OkV between the rod electrodes 121 functioning as an emitter and the plate electrode 131 functioning as a collector, a corona discharge is generated and neutral floating dusts are basically electrified in such a way that the rod electrodes 121 of a negative polarity attract floating dusts of a positive polarity and the plate electrode 131 of a positive polarity attracts floating dusts of a negative polarity due to Coulomb force, thereby collecting dusts in the air.

[56] In this case, the housing 100 including the empty space 101 may be formed as an additional element as described above but may be provided as a structure assembled with a peripheral device as a single body.

[57] On the other hand, as shown in FIG. 4, on a top of the electronic component part 110 below the empty space 101 of the housing, there may be provided elastic pin connectors 115 elastically protruded upwards to connect a power supply to power connection parts (not shown) formed on bottom surfaces of the emitter electrode part 120 and the collector electrode part 130, respectively. Accordingly, when installing the emitter electrode part 120 and the collector electrode part 130 in the empty space 101 inside the housing 100, the elastic pin connectors 115 are pressurized due to self- gravities of the emitter electrode part 120 and the collector electrode part 130, respectively, thereby improving contact performance to provide a stable current flow.

[58] Also, as shown in FIG. 4, on the frame 123 of the emitter electrode part 120 and the frame 133 of the collector electrode part 130, there may be provided hooks 125 and 135 coupled with protrusions 116 provided on the housing, respectively. There may be provided handles 126 and 136 hinge-connected and pivotally coupled with the frame 123 of the emitter electrode part 120 and the frame 133 of the collector electrode part 130. Accordingly, a user pivots the handles 126 and 136 sidewards and backwards, puts one of the emitter electrode part 120 and the collector electrode part 130, and selectively couples the hooks 125 and 126 with the protrusions 116, thereby easily attaching and detaching the emitter electrode part 120 and the collector electrode part 130 to and from the inside of the empty space of the housing 100.

[59] Accordingly, after colleting floating dusts in the air in a clean room, the emitter electrode part 120 and the collector electrode part 130 may be separated and reused by easily and conveniently cleaning floating dusts collected by the rod electrodes 121 and the plate electrode 131 by using cleaning fluid including alcohol etc, thereby notably improving maintenance characteristics.

[60] The apparatus according to an embodiment of the present invention may be used to not only purify the air in a clean room for a manufacturing process of semiconductors and liquid crystal displays, but also purify environmental pollution in the air in laboratories, operating rooms, sanatoriums, subway stations, painting processes, and darkrooms if necessary.

[61] On the other hand, there will be described collecting action according to an interaction between the plate electrode 131 and the rod electrodes 121 as follows.

[62] FIG. 5 is a view illustrating the interaction between the plate electrode 131 and the rod electrodes 121, and FIG. 6 is a top view illustrating a configuration of the arrangement of the plate electrode 131 and the rod electrodes 121.

[63] Referring to FIG. 5, the air around the rod electrodes 121 heads for the plate electrode 131 and with electrification thereof. In this case, a flow of the air heading for the plate electrode 131 forms a flow heading for the holes 132 formed on the plate electrode 131.

[64] That is, in the case of a discharge of the rod electrodes 121 functioning as an emitter, an electric field is concentrated on a point P facing a center part of the holes 132 of the plate electrode 131 functioning as a collector and an electric charge moves to an edge of the hole 132 of the plate electrode 131. In this case, floating dusts in the air are collected to the edge of the hole 132 and a flow of the air is induced in this process. That is, there is induced an ionic wind as the flow of the air passing through the hole 132 of the plate electrode 131 from the rod electrodes 121. At the same time, residual floating dusts in the air diffused to other areas but for the edge of the hole 132 may be electrified as a positive polarity and collected to the rod electrodes 121 again.

[65] In a process as described above, most of floating dusts in the air are collected onto a surface of the plate electrode 131 and the air passes through the holes 132 and is discharged backwards. In this case, to induce a flow of an ionic wind improving collecting performance, as shown in FIG. 6, lines vertically connecting a center part of the holes 132 of the plate electrode 131 may be disposed opposite to the respective rod electrodes 121. Also, to effectively collecting floating dusts, the holes 132 in a line formed on the plate electrode 131 may zigzag not to overlap with the holes 132 in adjacent lines in right and left thereof.

[66] As described above, the apparatus according to an embodiment of the present invention collects floating dusts by combination between the rod electrodes 121 arranged to form a surface shape facing the plate electrode 131 including the plurality of holes 132 and provides a degree of freedom capable of varying a design for collecting dusts as occasion demands by controlling the number of the holes 132, the arrangement and size thereof, and an interval between the rod electrodes 121, thereby notably increasing the collecting performance of an apparatus with a limited thickness and volume to embody a compact size thereof.

[67] On the other hand, as shown in FIGS. 1 to 4, the protection plates 160, formed of an insulating material, where a plurality of through holes 162 are formed to allow air to pass therethrough are detachably assembled with the front and the rear of the housing 100, thereby providing stable operation of high voltage devices such as the emitter electrode part 120 and the collector electrode part 130 and preventing a contact of a user.

[68] In addition, to more improve stable operation of the apparatus 10 and safety of the user, there may be provided a safety element selectively cutting off supplying a power depending on whether the protection plates 160 are assembled therewith.

[69] Hereinafter, referring to FIG. 7, there will be described a circuit configuration and the safety element of the apparatus according to an embodiment of the present invention.

[70] FIG. 7 is a circuit diagram illustrating the safety element of the apparatus.

[71] Referring to FIG. 7, an alternating current (AC) input terminal 106 is provided in the electronic component part 110 of the housing 100 and an input voltage passes through a fuse 601 preventing an overload and a main power switch 102 and is applied to a direct current (DC) converter 602. Also, an output terminal 107 may be connected to one side of the AC input terminal 106.

[72] A DC power converted by the DC converter 602 passes through the safety element, a main printed circuit board (PCB) 620 and a high voltage transformer 630 and is supplied to the emitter electrode part 120 and the collector electrode part 130. In this case, the safety element includes first and second sensors 111 and 112 provided on the front and rear of the electronic component part 110 formed below the empty space 101 of the housing 100 and sensing whether the protection plates 160 are assembled therewith and a third sensor 113 provided on a top of the electronic component part 110 and sensing whether one of the emitter electrode part 120 and the collector electrode part 130 is detached or not.

[73] When a safe mode is selected and any one of the first, second, and third sensors 111,

112, and 113 senses that an object is not coupled therewith, the safety element operates not to supply a power to the emitter electrode part 120 and the collector electrode part 130.

[74] In detail, the first, second, and third sensors 111, 112, and 113 form a line connected in series and it is switched to selectively supply a power to both ends of the line in series of the first and second sensors 111 and 112, thereby connecting the selection switch 103 determining whether to operate a safety mode. The selection switch 103 is installed on the front of the electronic component part 110. The selection switch 103 is turned on to operate the safety mode and any one of the first, second, and third sensors 111, 112, and 113 senses that an object is not coupled therewith, the power is not supplied to the emitter electrode part 120 and the collector electrode part 130. Via this, there is provided a stable operation of the apparatus and the safety may be notably improved. [75] On the other hand, when the selection switch 103 is turned off not to operate the safety mode, regardless of a state of sensing of the first and second sensors 111 and 121, when the object such as the emitter electrode part 120 and the collector electrode part 130 is coupled with the third sensor 113, the power may be supplied to the emitter electrode part 120 and the collector electrode part 130.

[76] On the other hand, the first, second, and third sensors 111, 112, and 113 are pressurized while an object of sensing is coupled therewith and may be formed of button type switches, respectively, to supply a power when pressurized. Referring to FIGS. 2 to 4, there will be described a process of sensing whether an object is coupled therewith or not by using the first, second, and third sensors 111, 112, and 113 as respective button type switches, as follows. In this case, the second sensor 112 is disposed identical to the first sensor 111 and has the same shape as that of the first sensor 111 and the first sensor 111 and the second sensor 112 are provided on the front and the rear of the electronic component part 110.

[77] In detail, referring to FIGS. 2 and 3, on the front and the rear of the electronic component par 110 below the empty space 101 of the housing 100, there are provided the first and second sensors 111 and 112 formed as button type switches, respectively. When the protection plates 160 are assembled therewith, the first and second sensors 111 and 112 are pressurized respectively and sense whether the protection plates 160 are assembled therewith. Also, the third sensor 113 is formed of a button type switch and pressurized when one of the emitter electrode part 120 and the collector electrode part 130 is assembled therewith, due to self-gravity thereof, thereby sensing whether the emitter electrode part 120 and the collector electrode part 130 are assembled therewith.

[78] Referring to FIG. 4, on an edge of the protection plate 160, there are provided hooks

165 with a groove 167 formed slanting downwards to be coupled with protrusions 117 respectively to be slid downwards along the slanting groove 167 in such a way that the protection plate 160 is pressurized and closely attached to an outer surface of the housing due to self-gravity thereof.

[79] In this case, the edge of the protection plate 160 installed on the front of the housing

100 pressurizes the first sensor 111 provided on the front of the electronic component part 110 and the edge of the protection plate 160 installed in the rear of the housing 100 pressurizes the second sensor 112 provided on the rear of the electronic component part 110 of the housing 100. Via this, depending on whether the first and second sensors 111 and 112 formed of button type switches are pressurized, thereby sensing whether the front and rear protection plates 160 are assembled, respectively.

[80] Also, the third sensor 113 formed of a button type switch on the top of the electronic component part 110 senses whether one of the emitter electrode part 120 and the collector electrode part 130 is assembled therewith.

[81] On the other hand, FIG. 8 is a perspective view illustrating an example of using the apparatus collecting floating dusts.

[82] Referring to FIG. 8, to intensively collect floating dusts in an object space of purifying, a plurality of the apparatuses 10 are installed in top and bottom, right and left of a plurality of containing parts and form one face of an assembly of the plurality of the apparatuses. A structure 201 with the plurality of containing parts to contain the apparatuses 10 may vary within a range of technical scope, thereby easily combining and disposing the apparatuses on a side of a main device sensitive to dusts in a clean room for manufacturing semiconductors and liquid crystal displays to notably improve a production yield.

[83] To correspond to various field applications, the apparatus 10 may provide improved collecting performance by using a particular configuration and a thin and relatively small size thereof.

[84] On the other hand, FIG. 9 is a perspective view illustrating another example of using the apparatus 10.

[85] Referring to FIG. 9, there are provided moving wheels 211 on a bottom of a frame

210 containing the apparatuses 10, thereby increasing efficiency of using.

[86] FIG. 10 is an exploded perspective view illustrating a polarity configuration of an apparatus collecting floating dusts according to another embodiment of the present invention, and FIG. 11 is a cross-sectional view illustrating main parts of the apparatus of FIG. 10. In this case, since the apparatus collecting floating dusts according to the present embodiment has the same configuration excluding that rod electrodes are separated from at a predetermined interval and opposite to a front and a rear of a plate electrode, a description on the same configuration will be omitted.

[87] Referring to FIG. 10, a collector electrode part 230 is detachably provided inside the frame of the housing 100 and includes a plate electrode 231 collecting floating dusts in the air.

[88] Also, inside the frame of the housing 100, a first emitter electrode part 220 and a second emitter electrode part 250 are detachably provided at a front and a rear of the collector electrode 230. The first emitter electrode part 220 and the second emitter electrode part 250 include frames 223 and 253 including plurality of first rod electrodes 221 and a plurality of second rod electrodes 251, separated from and opposite to a front and a rear of the plate electrode 231 and forming an ionic wind of the air therearound, respectively.

[89] On respective frames 233, 223, and 253 of the collector electrode part 230, the first emitter electrode part 220, and the second emitter electrode part 250, hooks 235, 225, and 255 and handles 236, 226, and 256 may be provided respectively to be easily detached from and attached to the housing 100.

[90] On the other hand, the first and second rod electrodes 221 and 251 and the plate electrode 231 are formed of a conductive material such as stainless steel and a conductive high polymer material and connected to a power supply via a high voltage transformer provided inside the housing 100. In this case, a power of the same polarity is supplied to the first rod electrodes 221 and the second rod electrodes 251 and a power of opposite polarity from that of the first and second rod electrodes 221 and 251 is supplied to the plate electrode 231.

[91] Referring to FIG. 11, ionic winds from the first and second rod electrodes 221 and

251 to the plate electrode 231 are formed to be opposite to each other. The ionic winds blow up and down along surfaces of the plate electrode 231, thereby collecting floating dusts in the air to the plate electrode 231. In this case, the collected air is discharged outwards via a flow moving up and down around a point P where an electric field is concentrated and outlets of the air may be formed on a top and a bottom of the housing 100 for such flow.

[92] Also, due to the flow formed along the front and the rear of the plate electrode 231, different from the apparatus 10 according to an embodiment of the present invention, it may be omitted to form holes 232 on the plate electrode 231.

[93] As described above, both surfaces of the plate electrode 231 are used to collect dusts, thereby notably improving collecting efficiency.

[94] As described above, exemplary embodiments have been shown and described.

Though specific terms are used herein, they are just used for describing the present invention but do not limit the meanings and the scope of the present invention disclosed in the claims. Therefore, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention. Accordingly, the technical scope of the present invention is defined by the claims and their equivalents.

[95]

[96]