Patent Publication Number: US-11040355-B2

Title: Electric dust collecting filter and electric dust collecting device comprising same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application under 35 U.S.C. § 371 of International Application No. PCT/KR2019/001334, filed on Jan. 31, 2019, which claims the benefit of Korean Patent Application No. 10-2018-0013930, filed on Feb. 5, 2018. The disclosures of the prior applications are incorporated by reference in their entirety. 
     TECHNICAL FIELD 
     The present invention relates to an electric dust collecting filter and an electric dust collecting device including the same. 
     BACKGROUND ART 
     A general electric dust collecting filter is a device that is mounted on an air conditioner or an air purifier to charge and collect foreign matters contained in air. The electric dust collecting filter includes a charging part that discharges the foreign matters in the air and charges the foreign matters and a dust collecting part that generates electric fields to collect the foreign matters charged by the charging part by using electrostatic force. When the air passes through the charging part and the dust collecting part, the foreign matters in the air are charged in the charging part, and then the charged foreign matters are collected in the dust collecting part. 
     For example, referring to Korea Patent Publication No. 10-2017-0103111, titled “electric dust collecting device”, a dust collecting part of the electric dust collecting device includes a plurality of electrodes, and the plurality of electrodes are spaced apart from each other to generate electric fields. The dust collecting part of the electric dust collecting device uses an electrode in the form of a film, which is lightweight and has good moldability, as the electrodes for generating the electric fields. 
     However, in the case of the related art, in the process of removing the foreign matters collected on the electrode having the film shape, frictional force between the foreign matters charged by the electric fields and the surface of the electrode increases, and thus, the foreign matters are not separated from the surface of the electrode to deteriorate dust collecting efficiency of an electric dust collecting filter. 
     DISCLOSURE OF THE INVENTION 
     Technical Problem 
     An object of the present invention is to provide an electric dust collecting filter that collects foreign matters in air to generate electric fields for removing the collected foreign matters and an electric dust collecting device including the same. 
     Technical Solution 
     An electric dust collecting filter according to the present invention includes a plurality of film electrodes disposed to be spaced a predetermined distance from each other, wherein DC power different from each other are respectively applied to the film electrodes adjacent to each other of the plurality of film electrodes to generate electric fields between the film electrode adjacent to each other and collect foreign matters, which are contained in air flowing between the plurality of film electrodes, onto the plurality of film electrodes, thereby providing clean air. 
     Also, each of the film electrodes of the electric dust collecting filter according to the present invention may include a first electrode part provided with a plurality of first wire electrodes spaced apart from each other and a second electrode part provided with second wire electrodes that are respectively provided between the plurality of first wire electrodes and are alternately disposed with the plurality of first wires, wherein AC power different from each other may be applied to the first electrode part and the second electrode part to generate electric fields between the plurality of first wire electrodes and the plurality of second wire electrodes, thereby separating the foreign matters, which are previously collected on the electric dust collecting filter, from the electric dust collecting filter. 
     Also, each of the film electrodes of the electric dust collecting filter according to the present invention may include a plurality of first wire electrodes spaced apart from each other, a plurality of second wire electrode that are alternately disposed with the plurality of first wire electrodes, and a third wire electrode disposed between the first wire electrode and the second wire electrode, which are adjacent to each other, wherein AC power different from each other may be applied to the first wire electrode, the second wire electrode, and the third wire electrode to generate electric fields between the first wire electrode, the second wire electrode, and the third wire electrodes, separate foreign matters, which are previously collected on the plurality of dust collecting filters, from the electric dust collecting filter, and adjust a moving direction of the separated foreign matters. 
     Advantageous Effects 
     According to the present invention, the power applied to the plurality of electrode parts provided in each of the electric dust collecting filters may be adjusted to collect the foreign matters in the air or separate the previously collected foreign matters from the electric dust collecting filters, thereby efficiently removing the foreign matters. 
     In addition, according to the present invention, each of the electric dust collecting filters may include the plurality of wire electrodes to smoothly generate the electric fields between the plurality of film electrode disposed to be spaced the predetermined distance from each other. 
     In addition, according to the present invention, the plurality of wire electrodes may be alternately disposed with respect to each other to generate smoothly the electric fields between the wire electrodes that are adjacent to each other and minimize the areas of the electric dust collecting filters, on which the foreign matters previously collected by the electric fields are not separated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electric dust collecting device according to a first embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the electric dust collecting device according to the first embodiment of the present invention. 
         FIG. 3  is an exploded perspective view of a dust collecting plate according to the first embodiment of the present invention. 
         FIG. 4  is a front view of the dust collecting plate according to the first embodiment of the present invention. 
         FIG. 5  is a cross-sectional view taken along line A-A of  FIG. 4 . 
         FIG. 6  is a view illustrating a state in which power is applied to the dust collecting plate according to the first embodiment of the present invention. 
         FIG. 7  is a view illustrating a state in which foreign matters are collected on the dust collecting part according to the first embodiment of the present invention. 
         FIG. 8  is a view illustrating a state in which the foreign matters collected on the dust collecting part are separated according to the first embodiment of the present invention. 
         FIG. 9  is a front view of a dust collecting plate according to a second embodiment of the present invention. 
         FIG. 10  is a cross-sectional view taken along line B-B of  FIG. 9 . 
         FIG. 11  is a view illustrating a state in which power is applied to the dust collecting plate according to the second embodiment of the present invention. 
         FIG. 12  is an exploded perspective view of an electric dust collecting device according to a third embodiment of the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, an electric dust collecting filter according to a first embodiment of the present invention will be described based on the drawings. 
       FIG. 1  is a perspective view of an electric dust collecting device according to a first embodiment of the present invention, and  FIG. 1  is an exploded perspective view of the electric dust collecting device according to the first embodiment of the present invention. 
     Referring to  FIGS. 1 and 2 , an electric dust collecting filter  10  according to a first embodiment of the present invention includes a case  11  defining a main body and a dust collecting part  100  that charges foreign matters in air to collect the charged foreign matters. Here, the dust collecting part  100  may be referred to as an “electric dust collecting filter”. 
     A space may be defined in the case  11 . The dust collecting part  100  may be disposed inside the case  11 . 
     The case  11  may include a first case  17  accommodating a portion of the dust collecting part  100  therein and a second case  18  accommodating the remaining portion of the dust collecting part  100  therein. The dust collecting part  100  may be coupled to the inside of the first case  17  and the second case  18 . The first case  17  and the second case  18  may be coupled to each other. In this embodiment, the first case  17  may be disposed below the dust collecting part  100 , and the second case  18  may be disposed above the dust collecting part  100 . 
     An inflow part  171  into which external air is introduced may be provided in the first case  17 . A discharge part  181  from which the air introduced into the inflow part  171  is discharged may be provided in the second case  18 . That is, the air introduced into the inflow part  171  may be discharged to the discharge part  181  after passing through the dust collecting part  100 . Also, a prefilter, a mesh filter, and the like for filtering foreign matters having relatively large particles from the flowing air may be further provided in the inflow part  171  and the discharge part  181 . 
     The dust collecting part  100  may be constituted by a plurality of dust collecting plates  110 . The plurality of dust collecting plates  110  may be disposed to be spaced a predetermined distance from each other. In detail, each of the plurality of dust collecting plates  110  may be provided in a band shape having a length direction L longer than a width direction W thereof. Each of the plurality of dust collecting plates  110  may be arranged to be spaced apart from each other in the width direction W. The dust collecting plates  110  adjacent to each other may have one surfaces facing each other. 
     The dust collecting part  100  may be provided to correspond to the inflow part  171  and the discharge part  181  and may be disposed inside the case  11 . The air introduced into the inflow part  171  may flow to the discharge part  181  after passing through the dust collecting part  100 , and the foreign matters may be separated from the air in the process of passing through the dust collecting part  100 . 
     The dust collecting part  100  may charge the foreign matters in the air by applying a high voltage to collect the charged foreign matters. For this, each of the plurality of dust collecting plates  110  constituting the dust collecting part  100  may be provided with electrode parts  130  and  140  (see  FIG. 3 ). The dust collecting part  100  may charge the foreign matters in the air or collect the charged foreign matters according to a change in high voltage applied to each of the plurality of dust collecting plates  110 . A power source  19  (see  FIG. 5 ) that applies a high voltage may be connected to the dust collecting part  100 . A controller (not shown) may be further provided in the power source  19  to control the high voltage applied to the dust collecting part  100 . Also, a grounding part (not shown) for grounding may be further connected to the dust collecting part  100 . 
     The dust collecting part  100  according to the first embodiment of the present invention may be applied to high-voltage DC power or AC power. When the high-voltage DC power is applied to the dust collecting part  100 , the dust collecting part  100  may charge the foreign matters in the air and collect the charged foreign matters. On the other hand, when the high-voltage AC power is applied to the dust collecting part  100 , the dust collecting part  100  may separate the foreign matters, which are collected on a surface of the dust collecting part  100 , from the surface of the dust collecting part  100 . 
     Hereinafter, the dust collecting plate  110  constituting the dust collecting part  100  will be described in detail. 
       FIG. 3  is an exploded perspective view of the dust collecting plate according to the first embodiment of the present invention,  FIG. 4  is a front view of the dust collecting plate according to the first embodiment of the present invention, FIG.  5  is a cross-sectional view taken along line A-A of  FIG. 4 , and  FIG. 6  is a view illustrating a state in which power is applied to the dust collecting plate according to the first embodiment of the present invention. 
     Referring to  FIGS. 3 to 6 , the dust collecting plate  110  according to the first embodiment of the present invention may include a dust collecting plate body  111  defining a main body. 
     The dust collecting plate body  111  may be provided in a band shape having a length direction L and a height direction H, which are longer than a width direction W thereof. In this embodiment, air may flow in the height direction H of the dust collecting plate body  111 , and the foreign matters contained in the air may be attached to both side surfaces of the dust collecting plate body  111 . Here, the both side surfaces may be understood as both side surfaces defined in the height direction H and the length direction L of the dust collecting plate body  111 . Also, the dust collecting plate body  111  may extend by a predetermined length or more in the height direction H, which is a direction parallel to the flow direction of the air. The predetermined length is to increase in time and area, in which the air is capable of contacting both side surfaces of the dust collecting plate body  111  while the air flows. 
     The dust collecting plate body  111  may include a first fixing part  112  and a second fixing part  113 . The first fixing part  112  and the second fixing part  113  may be understood as units for fixing the dust collecting plate body  111  to the case  11 . The first fixing part  112  may be disposed on one side of the dust collecting plate body  111 , and the second fixing part  113  may be disposed on the other side of the collecting plate body  111 . In this embodiment, the first fixing part  112  may be disposed at a left side of the dust collecting plate body  111 , and the second fixing part  113  may be disposed at a right side of the collecting plate body  111 . Each of the first fixing part  112  and the second fixing part  113  may protrude from the dust collecting plate body  111 . A portion of each of the protruding first fixing part  112  and the protruding second fixing part  113  may be bent. In this embodiment, each of the protruding first fixing part  112  and the protruding second fixing part  113  may be bent upward. 
     The dust collecting plate  110  may include an insulating part  120  and electrode parts  130  and  140 . 
     The dust collecting plate body  111  may define a main body by the insulating part  120  and the electrode parts  130  and  140 . The electrode parts  130  and  140  may be provided in plurality. In this embodiment, the electrode parts  130  and  140  may include a first electrode part  130  and a second electrode part  140 . The plurality of electrode parts  130  and  140  may be disposed to be spaced a predetermined distance from each other. Different electrodes or the same electrode may be applied to each of the plurality of electrode parts  130  and  140  according to the situation. In addition, each of the electrode parts  130  and  140  may be made of a conductive material. For example, the conductive material may be provided with copper, indium, carbon paste, or the like. 
     The insulating part  120  may be disposed to surround the electrode parts  130  and  140 . The insulating part  120  may prevent different electrode parts from contacting each other. Also, when power is applied to the electrode parts  130  and  140 , the insulating part  120  may provide an attachment surface to which the foreign matters in the air are attached. The insulating part  120  may include a first insulating film  121  and a second insulating film  122 . The insulating part  120  may be made of an insulating material. For example, the insulating material may be provided with glass, PCB, plastic, or the like. 
     In this embodiment, the dust collecting plate  110  may be referred to as a “film electrode”. This is because the dust collecting plate  110  has a long band shape, the electrode parts  130  and  140  are disposed inside the dust collecting plate  110 , and the insulating part  120  surrounds the outside of each of the electrode parts  130  and  140 . When the dust collecting plate  110  is referred to as the “film electrode”, the dust collecting plate body  111  may be referred to as a “film electrode body”. 
     Hereinafter, the electrode parts  130  and  140  and the insulating part  120  will be described in detail. 
     The first electrode part  130  of the electrode parts  130  and  140  may include a first electrode part body  131 , a first power apply part  132 , and a first wire  133 . The first electrode body  131  may be disposed in an upper portion of the dust collecting plate body  111 . The first power apply part  132  and the first wire  133  may extend from the first electrode part body  131 . The first power apply part  132  may be connected to the power source  19 . The first electrode part  130  may receive power from the power source  19  through the first power apply part  132 . The first wire  133  may be provided in plurality. The plurality of first wires  133  may be disposed to be spaced apart from each other. The plurality of first wires  133  according to this embodiment may extend downward from the first electrode part body  131 . Also, a second wire  143 , which will be described later, may be disposed between the first wires  133  adjacent to each other. For example, the first electrode part  130  may be provided in the form of a hair comb in which a combs are disposed downward from an upper side. Also, the first wire  133  may be referred to as a “first wire electrode”. 
     The second electrode part  140  of the electrode parts  130  and  140  may include a second electrode part body  141 , a second power apply part  142 , and a second wire  143 . The second electrode part body  141  may be disposed in a lower portion of the dust collecting plate body  111 . The second power apply part  142  and the second wire  143  may extend from the second electrode part body  141 . The second power apply part  142  may be connected to the power source  19 . The second electrode part  140  may receive power from the power source  19  through the second power apply part  142 . The second wire  143  may be provided in plurality. The plurality of second wires  143  may be disposed to be spaced apart from each other. The plurality of second wires  143  according to this embodiment may extend upward from the second electrode part body  141 . Also, the first wire  133  may be disposed between the second wires  143  adjacent to each other. For example, the second electrode part  140  may be provided in the form of a hair comb in which combs are disposed downward from the upper side. Also, the second wire  143  may be referred to as a “second wire electrode”. 
     That is, the first wire  133  and the second wire  143  may be alternately disposed while being spaced apart from each other. Alternatively, the first wire  133  and the second wire  143  may be repeatedly disposed in a state of being spaced apart from each other. Also, the first wire  133  and the second wire  143  may extend in a direction parallel to the flow direction. As a distance between the first wire  133  and the second wire  143  decreases, the foreign matters collected on the surface of the dust collecting plate  110  may be effectively separated from the surface of the dust collecting plate  110 . 
     The first insulating film  121  of the insulating part  120  may be disposed at one side of each of the electrode parts  130  and  140 . The second insulating film  122  of the insulating part  120  may be disposed at the other side of each of the electrode parts  130  and  140 . The first insulating film  121  and the second insulating film  122  may be coupled to each other to surround the electrode parts  130  and  140 . That is, the electrode parts  130  and  140  may be disposed inside the first insulating film  121  and the second insulating film  122 . 
     The insulating part  120  may further include a connection film  123 . The connection film  123  may be disposed in a space defined between the first wire  133  of the first electrode part  130  and the second wire  143  of the second electrode part  140  to connect the first insulating film  121  to the second insulating film  122 . Also, the connection film  123  may be understood as a portion at which the first insulating film  121  and the second insulating film  122  protrude to be coupled to each other. 
     The dust collecting part  100  may receive power from the power source  19 . Each of the plurality of dust collecting plates  110  may be connected to the power source  19 . In detail, the first power apply part  132  of the first electrode part  130  and the second power apply part  142  of the second electrode part  140  may be connected to the power source  19 . The power source  19  may supply DC power, which are different from each other, to the plurality of dust collecting plates  110 , respectively. In addition, the power source  19  may supply AC power, which are different from each other, to the first electrode part  130  and the second electrode part  140  provided in the plurality of dust collecting plates  110 , respectively. 
     That is, the dust collecting part  100  may operate in a “dust collecting mode” and a “dust separating mode” according to whether AC power or DC power is supplied to the dust collecting part  100 , and whether a positive (+) or negative (−) pole is applied to the first electrode part  130  and the second electrode part  140 , which are respectively provided in the plurality of dust collecting plates  110 . 
     (a) of  FIG. 6  is a view illustrating a state in which charged foreign matters D are collected on one dust collecting plate  110  in the “dust collecting mode”. 
     (b) of  FIG. 6  is a view illustrating a state in which the foreign matters D, which are previously collected on the one dust collecting plate  110 , are separated from the one dust collecting plate  110  in the “dust separating mode”. 
       FIG. 7  is a view illustrating a state in which the foreign matters are collected on the dust collecting part according to the first embodiment of the present invention, and  FIG. 8  is a view illustrating a state in which the foreign matters collected on the dust collecting part are separated according to the first embodiment of the present invention. 
     Referring to  FIGS. 7 and 8 , when the collecting foreign matters in the air are collected through the dust collecting part  100 , the power source  19  may supply different DC power to the plurality of dust collecting plates  110 , respectively. Here, the collection of the foreign matters in the air through the dust collecting part  100  may be referred to as a “dust collecting mode”. 
     In detail, power having a negative (−) pole may be applied to one dust collecting plate  110   a  of the plurality of dust collecting plates  110 , and power having a positive (+) pole may be applied to the other dust collecting plate  110   b.  The one dust collecting plate  110   a  to which the power having the negative (−) pole is applied and the other dust collecting plate  110   b  to which the power having the positive (+) pole is applied may be disposed adjacent to each other. That is, the power source  19  may alternately supply the negative (−) and positive (+) poles to the plurality of dust collecting plates  110 . Alternatively, the power source  19  may sequentially supply the negative (−) and positive (+) poles to the plurality of dust collecting plates  110 . Here, the same negative (−) power is applied to the first electrode part  130  and the second electrode part  140  of the one dust collecting plate  110   a,  and the same positive (+) power may be applied to the first electrode part  130  and the first electrode part  130  of the other dust collecting plate  110   b.    
     Thus, when different DC power are applied to the one dust collecting plate  110   a  and the other dust collecting plate  110   b , which are adjacent to each other, the foreign matters contained in the air passing between the one dust collecting plate  110   a  and the other dust collecting plate  110   b  may be charged in the dust collecting plate and thus be collected on the other dust collecting plate  110   b.    
     When the foreign matters collected on the surface of the dust collecting part  100  are separated from the dust collecting part  100 , the power source  19  may supply AC power, which are different from each other, to the first electrode part  130  and the second electrode part  140  provided in the plurality of dust collecting plates  110 , respectively. Here, the separation of the foreign matters collected in the dust collecting part  100  from the dust collecting plate  110  may be referred to as a “dust separating mode”. Also, the AC power applied to the first electrode part  130  and the second electrode part  140  provided in each of the dust collecting plates  110  may be controlled in waveform, frequency, voltage to adjust a degree of separation of the foreign matters from the dust collecting plate  110 . For example, the waveform of the AC power may be provided as a sine waveform or a square waveform. 
     In detail, the negative (−) power may be applied to the first electrode part  130   a  provided in one dust collecting plate  110   a  of the plurality of dust collecting plates  110 , and the positive (+) power may be applied to the second electrode part  140   a.  The negative (−) power, which is applied to the first electrode part  130   a,  may be transmitted to the plurality of first wires  133 , and the positive (+) power, which is applied to the second electrode part  140   a,  may be transmitted to the plurality of second wires  143 . The negative (−) power may be applied to the first electrode part  130   b  provided in the other dust collecting plate  110   b  of the plurality of dust collecting plates  110 , and the positive (+) power may be applied to the second electrode part  140   b.  The negative (−) power, which is applied to the first electrode part  130   b,  may be transmitted to the plurality of first wires  133 , and the positive (+) power, which is applied to the second electrode part  140   b,  may be transmitted to the plurality of second wires  143 . Also, the one dust collecting plate  110   a  and the other dust collecting plate  110   b  may be disposed adjacent to each other. 
     Thus, when the different AC power are applied to the first electrode parts  130   a  and  140   a  and the second electrode parts  130   b  and  140   b,  which are provided in the one dust collecting plate  110   a  and the other dust collecting plate  110   b , the foreign matters collected on the surface of the dust collecting plate  110  may be separated from the surface of the dust collecting plate  110  by electric force generated between the first electrode parts  130   a  and  140   a  and the second electrode parts  130   b  and  140   b.  The foreign matters separated from the dust collecting part  100  may fall in the direction of gravity by its own weight. 
     According to the configuration of the present invention, the foreign matters contained in the air may be removed through the dust collecting mode of the dust collecting part  100 . The high-voltage DC power may be applied to the different dust collecting plates  110  to collect the foreign matters, thereby improving collecting efficiency of the foreign matters contained in the air. 
     Also, the foreign matters collected in the dust collecting part  100  may be easily removed through the dust separating mode of the dust collecting part  100 . The foreign matters attached to the surface of the dust collecting part  100  may be pushed out by the electric force generated by applying the high voltage AC power between the first electrode part  130  and the second electrode part  140  of the dust collecting part  100  to cleanly remove the foreign matters attached to the dust collecting part  100 . 
       FIG. 9  is a front view of a dust collecting plate according to a second embodiment of the present invention,  FIG. 10  is a cross-sectional view taken along line B-B of  FIG. 9 , and  FIG. 11  is a view illustrating a state in which power is applied to the dust collecting plate according to the second embodiment of the present invention. 
     Referring to  FIGS. 9 to 11 , a dust collecting plate  210  according to a second embodiment of the present invention is characterized in that the number of electrode parts is changed in the description of the dust collecting plate according to the first embodiment. Thus, in the second embodiment, the description of the same configuration as the first embodiment may be cited from the description of the first embodiment. 
     A dust collecting part according to the second embodiment of the present invention may include a plurality of dust collecting plates  210 . Also, each of the plurality of dust collecting plates  210  may include a dust collecting plate body  211 . The dust collecting plate body  211  may include an insulating part  220  and a plurality of electrode parts  230 ,  240 , and  250 . The dust collecting plate body  211  may define a main body of the dust collecting plate  210  and may further include a first fixing part  212  and a second fixing part  213 . 
     The insulating part  220  may be provided to surround the plurality of electrode parts  230 ,  240 , and  250  and may include a first insulating film  221  and a second insulating film  222 . Also, the insulating part  120  may further include a connection film  223  for connecting the first insulating film  221  to the second insulating film  222 . 
     The plurality of electrode parts  230 ,  240 , and  250  may be disposed inside the insulating part  220 . In detail, the plurality of electrode parts  230 ,  240 , and  250  may be disposed between the first insulating film  221  and the second insulating film  222 . Also, the plurality of electrode parts  230 ,  240 , and  250  may be disposed to be spaced apart from each other inside the insulating part  220 . 
     The plurality of electrode parts  230 ,  240 , and  250  may include a first electrode part  230 , a second electrode part  240 , and a third electrode part  250 . The first electrode part  230 , the second electrode part  240 , and the third electrode part  250  may be sequentially disposed in a state of being spaced apart from each other. In this embodiment, the plurality of electrode parts  230 ,  240 , and  250  may be provided in at least three or more. The plurality of electrode parts  230 ,  240 , and  250  may be connected to a power source  19  to receive power. In this embodiment, the third electrode part  250  will be described as being disposed between the first electrode part  230  and the second electrode part  240 . Also, the first electrode part  230 , the second electrode part  240 , and the third electrode part  250  may be disposed to be spaced a uniform interval from each other. 
     The first electrode part  230  may include a first electrode part body  231 , a first power apply part  232 , and a plurality of first wires  233 . The second electrode part  240  may include a second electrode part body  241 , a second power apply part  242 , and a plurality of second wires  243 . The plurality of first wires  233  may extend from the first electrode part body  231 , and the plurality of second wires  243  may extend from the second electrode part body  241 . Each of the second wires  243  may be disposed between the plurality of first wires  233  adjacent to each other. Also, each of the first wires  233  may be disposed between the plurality of second wires  243  adjacent to each other. In this embodiment, the third electrode part  250  may be disposed between the first wire  233  and the second wire  243  that are adjacent to each other. 
     The third electrode part  250  may include a third electrode part body  251  and a third wire  253 . 
     The third electrode part body  251  may be disposed between the first electrode part  230  and the second electrode part  240 , which are spaced apart from each other. The third electrode part body  25  may be provided in plurality, and each of the plurality of third electrode part bodies  25  may be provided between first and second wires  233  and  243  that are adjacent to each other. The third electrode part body  251  may function as a third apply part. The third electrode part bodies  251  spaced apart from each other may be connected to each other. That is, the plurality of third electrode part bodies  251  may be connected to the power source  19  to receive the same power. In this embodiment, the third electrode part body  251  may be disposed between one first wire  233  of the plurality of first wires  233  adjacent to each other and the second wire  243  disposed between the plurality of first wires  233 . Also, the third electrode part body  251  may be disposed in an upper portion of the dust collecting plate body  211 . 
     The third wire  253  may extend from the third electrode body  251 . The third wire  253  may be disposed between the first wire  233  and the second wire  243 . The third wire  253  may extend in a direction parallel to the first wire  233  and the second wire  243 . In this embodiment, the third wire  253  may extend in a direction that is directed downward from the upper side of the dust collecting plate body  211 . Also, the third wire  253  may be disposed to be spaced apart from the first electrode part  230  and the second electrode part  240 . 
     That is, the first wire  233 , the second wire  243 , and the third wire  253  may be disposed parallel to each other in the dust collecting plate  210  according to this embodiment. In addition, the first wire  233 , the second wire  243 , and the third wire  253  may extend in a direction parallel to a flow direction of air. 
     The dust collecting part may perform a “dust collecting mode” or “a dust separating mode” according to a change in power applied to the first electrode part  230 , the second electrode part  240 , and the third electrode part  250 , which are respectively provided in the dust collecting plates  210 . 
     According to the configuration according to the second embodiment of the present invention, when the separation of the foreign matters collected on a surface of the dust collecting plate  210  are separated from the surface of the dust collecting plate  210  in the dust separating mode, a moving direction of the foreign matters may be adjusted. 
     In detail, the third wire  253  may be disposed between the first wire  233  and the second wire  243 , and AC power may be respectively applied to the first wire  233 , the second wire  243 , and the third wire  253 . Here, the AC power respectively applied to the first wire  233 , the second wire  243 , and the third wire  253  may be controlled in waveform, frequency, voltage to adjust a degree of separation of the foreign matters from the dust collecting plate  110  and the moving direction of the separated foreign matters. For example, the waveform of the AC power may be provided as a square waveform. Also, a phase difference of the AC power may be provided at an interval of 120 degree. 
     When the moving direction in which the foreign matters separated from the dust collecting plate  210  move is adjusted, the diversity of positions at which the dust collecting plate  210  is installed may increase. That is, in a state in which the dust collecting plate  210  is disposed in a horizontal direction, when the foreign matters collected on a top surface of the dust collecting plate  210  are removed, the moving direction of the separated foreign matters may be adjusted to easily remove the foreign matters existing on the top surface of the dust collecting plate  210 . Also, since the moving direction of the separated foreign matters is adjusted to allow the foreign matters to move to a desired position, a maintenance and repair operation may be easy. 
     (a) of  FIG. 11  is a view illustrating a state in which charged foreign matters D are collected on one dust collecting plate  210  in the “dust collecting mode”. 
     (b) of  FIG. 11  is a view illustrating a state in which the foreign matters D, which are previously collected on the one dust collecting plate  210 , are separated from the one dust collecting plate  210  in the “dust separating mode”. Here, the foreign matters D separated from the dust collecting plate  210  may move in a state of having directionality by electric fields generated in the dust collecting plate  210 . 
       FIG. 12  is an exploded perspective view of an electric dust collecting device according to a third embodiment of the present invention. 
     Referring to  FIGS. 1 and 12 , an electric dust collecting filter  30  according to the third embodiment of the present invention includes a case  31  defining a main body, a charging part  32  that charges foreign matters in air, and a dust collecting part  300  that collects the foreign matters charged in the charging part  32 . 
     A space may be defined in the case  31 . The charging part  32  and the dust collecting part  300  may be disposed inside the case  31 . The charging part  32  and the dust collecting part  300  may be disposed to be spaced apart from each other in the case  31 . 
     The case  31  may include a charging case  37  accommodating the charging part  32  therein and a dust collecting case  38  accommodating the dust collecting part  300  therein. The charging part  32  may be coupled to the inside of the charging case  37 . The dust collecting part  300  may be coupled to the inside of the dust collecting case  38 . The charging case  37  and the dust collecting case  38  may be coupled to each other. 
     The charging case  37  may be provided with an inflow part  371  through which external air flows. A discharge part  381  through which the air introduced into the inflow part  371  is discharged may be provided in the dust collecting case  38 . That is, the air introduced into the inflow part  371  may be discharged to the discharge portion  381  after sequentially passing through the charging part  32  and the dust collecting part  300 . Also, a prefilter, a mesh filter, and the like for filtering foreign matters having relatively large particles from the flowing air may be further provided in the inflow part  371  and the discharge part  381 . 
     The charging part  32  is discharged by a high voltage to charge the foreign matters in the air. The charging part  32  may include a plurality of wire electrodes  321 , to which the high voltage is applied, and a plurality of counter electrode plates  322  spaced apart from each of the plurality of wire electrodes. When the high voltage is applied to the wire electrode  321 , the charging part  32  generates corona discharge between the wire electrode  321  and the counter electrode plate  322  to ionize molecules in the air. The ions generated in the charging part  32  may charge the foreign matters in the air. For example, high-voltage DC power may be applied to the charging part  32 . 
     The charging part  32  may be provided to correspond to the inflow part  371  and may be disposed inside the charging case  37 . The charging part  32  may be fixed by being coupled to the inside of the charging case  37 . The charging part  32  may be disposed upstream of the dust collecting part  300  with respect to an air flow inside the case  31 . The charging part  37  and the dust collecting part  300  may be disposed to be spaced apart from each other. A ground part (not shown) that is grounded to the power source  19  (see  FIG. 6 ) to which the high voltage is applied may be connected to the charging part  32 . 
     The dust collecting part  300  may collect the charged foreign matters by generating the electric fields. When the high voltage is applied to the dust collecting part  300 , electrostatic force may be generated to collect the foreign matters charged in the charging part  32  in the dust collecting part  300  by the electrostatic force. The dust collecting part  300  may be provided to correspond to the discharge part  381  and may be disposed inside the dust collecting case  38 . The dust collecting part  300  may be fixed to the inside of the dust collecting case  38 . The dust collecting part  300  may be disposed downstream of the charging part  32  with respect to the air flow inside the case  31 . The power source  19  for applying the high voltage and the ground part (not shown) for grounding may be connected to the dust collecting part  300 . 
     That is, according to the present invention, the charging part  32  may be disposed upstream of the dust collecting part  300  with respect to the air flow inside the case  31  to increase in amount of foreign matters collected in the dust collecting part  300  and remove more foreign matters from the air.