JP2010063964A - Dust collecting apparatus - Google Patents

Abstract

The present invention provides a dust collector that does not require a charged portion having a complicated structure and has high dust collection performance while preventing sparks occurring between electrode plates.
In a dust collector 4 in which a dust repellent electrode plate 2 and a dust collecting electrode plate 3 are alternately stacked while providing a space 10 and a different voltage is applied to each electrode plate, the dust repellent electrode plate 2 and the collector electrode plate 2 are collected. At least one of the dust electrode plates 3 is a semiconductive electrode plate having a surface resistivity of 10 7-11 Ω / □, and causes a discharge between the dust repellent electrode plate 2 and the dust collecting electrode plate 3. Electrify and collect dust.
[Selection] Figure 2

Description

  The present invention relates to a dust collector for removing particulate suspended matters in the air in the field of air purification.

  Particulate suspended matter in the air, that is, dust, has been known as a cause of illnesses such as asthma and has been a target for removal in the past, but in recent studies, the particle size is 2.5 micrometers or less. There is a report that dust (so-called PM2.5) may induce diseases such as lung cancer, and further improvement of the collection technology is required. Among them, dust collectors that use electrostatic precipitating technology are excellent at collecting small particles with a particle size of micrometer or less, and have a low-pressure loss characteristic. There is a need for improved performance.

  Conventionally, as this type of dust collector, a charged part that charges dust by discharge is provided in the previous stage, and electrode plates are stacked in the subsequent stage, and different electric voltages are applied alternately to form an electric field to charge the charged dust. What provided the dust collection part which collects is known. As an example to which this configuration is applied, patent documents show a dust collector in which an electrode to which one voltage is applied in a dust collector is covered with a resin film as an insulator. Hereinafter, the dust collector will be described with reference to FIG. As shown in FIG. 9, the charging unit 101 includes a linear charging unit discharge electrode 102 and a charging unit counter electrode plate 103, and a voltage application electrode plate 105 and a dust collection electrode plate on the downstream side of the charging unit 101. A dust collecting section 104 is provided in which 106 and 106 are alternately stacked at a predetermined interval. Although not shown in the figure, the voltage application electrode plate 105 is covered with a resin film which is an insulator. Usually, in the charging unit 101, 5 to 15 kV is provided between the charging unit discharge electrode 102 and the charging unit counter electrode plate 103, and 2 between the voltage applying electrode plate 105 and the dust collecting electrode plate 106 of the dust collecting unit 104. A predetermined voltage is applied to each electrode by the high voltage power source 107 so as to give a potential difference of ˜6 kV.

  In the above configuration, in the charging unit 101, an unequal electric field is created between the charging unit discharge electrode 102 and the charging unit counter electrode plate 103. At this time, in the vicinity of the charging unit discharge electrode 102 having a linear shape, A very strong electric field is created. For this reason, the charge-holding substance that is slightly contained in the air, such as air ions, is accelerated and collides with the air molecules, and the electrons are separated from the air molecules. The separated electrons are also accelerated and collide with air molecules, and the electrons are separated from the air molecules. The phenomenon where electrons are separated from air molecules by collision with electrons is called ionization. In addition, the phenomenon in which a large number of electrons separate from air molecules by repeated ionization is called electron avalanche, but positive-polarity air ions that are separated by this avalanche, or negative-polarity air that combines with separated electrons. Ions are created. Then, air ions having a polarity different from that of the charged portion discharge electrode 102 are absorbed by the charged portion discharge electrode 102 and returned to air molecules, and conversely, air ions having the same polarity are repelled from the charged portion discharge electrode 102 by the electric field. Is received and diffused and moved in the direction of the charged portion counter electrode plate 103.

The discharge phenomenon in which the air near the charged portion discharge electrode 102 is turned into air ions by causing ionization and electron avalanche is called corona discharge. The discharge phenomenon is generated by corona discharge and mainly has the same polarity as the charged portion discharge electrode 102. As the ions combine with the dust passing through the charging unit 101, the dust is charged. The charged dust is introduced into the dust collecting portion 104 along the flow of the air flow, and adheres mainly to the dust collecting electrode plate 106 under the force of the electric field created between the voltage applying electrode plate 105 and the dust collecting electrode plate 106. Then, clean air is blown out from behind the dust collecting unit 104. Since the voltage application electrode plate is covered with an insulating resin film, it does not cause a short circuit even when it comes into contact with the dust collection electrode plate, and at the same time prevents spark discharge (hereinafter referred to as spark) that may occur between the dust collection electrode plate It has a structure to do.
Japanese Patent No. 3261167

  In a dust collector as described in the patent document, a charging part is required separately from the dust collecting part in order to charge the dust. The charged part is composed of a discharge electrode having a linear or spine shape and a counter electrode, and corona discharge is generated at the discharge electrode, so that the tip of the spine discharge electrode is worn and sufficient corona discharge is generated. There is a problem that a failure such that the wire cannot be raised or the wire is cut if it is a linear discharge electrode is likely to occur. In addition, it is necessary to configure the discharge electrode and the counter electrode in a state where they are insulated with air, and thus it is difficult to configure a charged portion having such a complicated structure. In addition, the dust collector is covered with an insulating resin film to ensure the insulation of the voltage application electrode plate, so a solid coating is required to obtain reliable insulation, and advanced processing is required. Requires technology. In addition, charges are generated on the surface of the resin film by applying a voltage. However, if the distance between the electrodes is not sufficient, the charge accumulated on the surface of the resin film jumps over the space and moves to the dust collecting electrode plate. There is a problem in that a discharge accompanied by a discharge, that is, a spark occurs.

  The present invention solves such a conventional problem, and since it does not require a charged portion having a complicated structure, it can be prepared easily, and it prevents sparks occurring between electrode plates and provides high dust collection performance. It aims at providing the dust collector which can be obtained.

  In order to achieve the above object, the dust collector of the present invention is a dust collector in which dust repelling electrode plates and dust collecting electrode plates are alternately stacked, and different voltages are applied to the respective electrode plates. And at least one of the dust collecting electrode plates is a semiconductive electrode plate having a surface resistivity of 10 7 to 11 11 Ω / □, and causes a discharge between the dust repellent electrode plate and the dust collecting electrode plate. It is characterized in that dust is charged and collected.

  ADVANTAGE OF THE INVENTION According to this invention, the dust collector which can be produced easily, is lightweight, can prevent the spark which arises between electrode plates, and can acquire high dust collection performance can be provided.

  In order to achieve the above object, the dust collector of the present invention is a dust collector in which dust repellent electrode plates and dust collector electrode plates are alternately stacked while providing a space, and different voltages are applied to the respective electrode plates. At least one of the dust repellent electrode plate and the dust collecting electrode plate is a semiconductive electrode plate having a surface resistivity of 10 7 to the 11th power Ω / □, and between the dust repellent electrode plate and the dust collecting electrode plate It is characterized by charging and collecting dust by causing discharge. A high potential difference is applied between the dust repellent electrode plate and the dust collecting electrode plate by applying a voltage. In particular, corona discharge occurs at the edge portions of the opposing electrode plates. At this time, when both electrode plates are made of a conductor such as metal, the movement of electric charges supplied from the high voltage power source is not limited, and therefore, spark discharge, that is, spark, occurs before corona discharge occurs. Sparks occur when electrons and ions are directed directly to the opposite electrode plate in an unspecified narrow area at the edge, so the action of ionizing air to create air ions is small, and the area is narrow, so dust is reduced. Small effect of charging. In addition, since it becomes a source of noise and an ignition source of gas and combustible substances, it is necessary to prevent the generation of sparks.

  In the dust collector of the present invention, since at least one of the dust repellent electrode plate and the dust collecting electrode plate is a semiconductive electrode plate having a surface resistivity of 10 7-11 Ω / □, it is supplied from a high voltage power source. Charge transfer is limited. Therefore, regardless of the edge portion, the flat surface portion, or the portion where dust accumulates and forms a spine-like bulge, a spark that can be generated everywhere due to a sudden charge movement is prevented. In particular, the electric field strength increases at the edge portion, and discharge occurs. At this time, by using a semiconductive electrode plate, the action of restricting the movement of electric charge can be obtained, so that the electric charge suddenly jumps out into the air and does not cause a spark, but corona discharge that generates air ions by ionizing the air is generated. . Air ions obtained by corona discharge combine with dust in the air to charge the dust, and the charged dust is either electrode plate by the electric field provided between the dust repulsion electrode plate and the dust collection electrode plate. It moves toward and adheres and is collected. As an example, when a positive high voltage is applied to the dust repellent electrode plate and 0 kV is applied to the dust collecting electrode plate, the dust is positively charged and positively charged by corona discharge that occurs particularly at the edge of the dust repellent electrode plate. The dust receives a repulsive force by the dust repellent electrode plate to which a positive high voltage is applied and a suction force from the dust collecting electrode plate, and is mainly collected on the surface of the dust collecting electrode plate. According to such a principle, it is possible to prevent the occurrence of sparks and collect dust without providing a charging portion.

  The dust collecting device according to claim 2 is characterized in that at least one of the dust repellent electrode plate and the dust collecting electrode plate has an edge on the surface. Edges are naturally formed on the end surfaces of the dust repellent electrode plate and the dust collecting electrode plate, and corona discharge can be generated from the edges of the end surfaces to charge the dust. The bar or the pointed portion of the protrusion, that is, the edge is provided by a method such as providing a bar having a square cross section on the surface of the dust electrode plate or providing a protrusion having a sharp tip. By applying a large potential difference between the dust repellent electrode plate and the dust collecting electrode plate, corona discharge occurs from the edge provided on the surface of the electrode plate and the dust is charged, so that higher dust collection efficiency can be obtained. As a method of easily providing an edge on the surface of the electrode plate, a method of providing a slit on at least one of the dust repellent electrode plate and the dust collecting electrode plate as described in claim 3 can be mentioned. The slit provided on the front surface may or may not penetrate to the back surface as long as an edge having a natural corner is formed by providing the slit. Corona discharge occurs from the corner edge obtained by providing the slit, and higher dust collection efficiency can be obtained by charging the dust.

  The corona discharge occurs at the edge because the electric field strength increases at the corners of the edge. As a method of causing the corona discharge other than by forming the edge, the dust repellent electrode plate as described in claim 4 And providing a dot-like conductive part on at least one surface of the dust collecting electrode plate. The electric charges on the surface of the electrode plate gather at the point-like conductive part, and the electric field strength around the point-like conductive part increases. Corona discharge occurs due to this increase in electric field strength, and higher dust collection efficiency can be obtained by charging dust in the air. As another method having a higher effect, a spine-like conductive portion may be provided on the surface of at least one of the dust repellent electrode plate and the dust collecting electrode plate as described in claim 5. Since the conductive portion has a spine shape, the electric field strength increases at the spine tip of the conductive portion where the charges on the surface of the electrode plate are collected. As a result, corona discharge is generated and the dust is charged, whereby higher dust collection efficiency can be obtained. As a method for forming the conductive part, as described in claim 6, an inorganic conductive paint is applied and dried. Corona discharge that occurs in the conductive part generates oxidizing substances such as ozone and radicals as by-products. Therefore, the conductive part is formed with a conductive paint containing a metal oxide having conductivity such as an inorganic material resistant to oxidation, for example, a metal powder such as silver, aluminum, or copper, or antimony oxide, tin oxide, or indium-tin composite oxide. This makes it possible to increase the durability of the conductive part.

  The dust collector according to claim 7 is characterized in that the semiconductive electrode plate is formed of a resin having semiconductivity. In order to obtain a semiconductive electrode plate, the surface resistivity should be 10 7 to 11th power Ω / □, and therefore it is possible to configure the semiconductive electrode plate by forming it with a resin having semiconductivity. Become. Examples of the resin having semiconductivity include a resin having a water absorption property such as nylon, and the semiconductivity depends on humidity in the air. As a method of obtaining stable semiconductivity without depending on humidity in the air, a method of including an ion conductive polymer in an insulating resin as described in claim 8 can be mentioned. A polymer having a quaternary ammonium salt in the molecular structure as an ion conductive polymer will be described below as an example. The quaternary ammonium salt has four alkyl groups bonded to the central ammonia atom, and has a positive charge as a whole. Since it has a structure in which anions such as chlorine ions are ion-bonded therewith, it has an ionic conductivity and therefore has a property of passing a slight charge. In addition, since the ion conductive polymer has ionic quaternary ammonium salt in the molecular structure of the polymer in advance, it is not easily affected by humidity and has a characteristic of passing a slight amount of charge even at low humidity. It has the characteristic that it can ensure. By using a material in which this ion conductive polymer is contained in an insulating resin, it is possible to obtain a semiconductive electrode plate having stable semiconductivity without being affected by humidity.

  The dust collector according to claim 9 is characterized in that the semiconductive electrode plate is provided with a semiconductive layer having a surface resistivity of 10 7 to 11 11 Ω / □ on the surface of the insulating substrate. It is what. In order to generate an electric field between the dust repellent electrode plate and the dust collecting electrode plate at the same time as causing a discharge at the dust repellent electrode plate and the dust collecting electrode plate, in particular, an electric potential difference should be generated between the respective electrode plate surfaces. . In other words, since it is only necessary to charge only the surface, it is easy to use an insulating substrate as a support base for the electrode plate and to provide a semiconductive layer having a surface resistivity of 10 7 to 11th power / square on the surface. It is possible to form an electrode plate having a surface resistivity of 10 7-11 Ω / □. Examples of the material for the insulating substrate include an insulating resin or ceramic, or a laminated sheet obtained by hardening a glass fiber sheet with an epoxy resin or the like.

  Further, the dust collector according to claim 10 is a device in which a semiconductive coating having a coating surface of 10 7-11 Ω / □ is applied to the surface of the insulating substrate and dried to provide a semiconductive layer. It is a semiconductive electrode plate. As a specific example, a surface resistivity of 10 7-11 Ω / □ is obtained by applying a coating containing a water-absorbing polymer such as polyvinyl alcohol, sodium polyacrylate, and amylose on the surface of the insulating substrate and drying it. The method of obtaining the semiconductive film | membrane which has is mentioned. The water-absorbing polymer has a property of easily absorbing moisture in the air, and has a property of passing electricity slightly by absorbing moisture in the air. A semiconductive layer having a surface resistivity of 10 7 to 11 11 Ω / □ is obtained by applying a coating containing a water-absorbing polymer to the surface of the insulating substrate and drying.

  Incidentally, the surface resistivity of a semiconductive layer containing a water-absorbing polymer is likely to fluctuate depending on the humidity level. As a method for providing a semiconductive layer which is not easily affected by humidity, a method using a solution containing a semiconductive metal oxide as a semiconductive paint as described in claim 11 can be specifically mentioned. By applying a semiconductive paint containing a semiconductive metal oxide such as zinc oxide, antimony oxide, titanium oxide, ruthenium oxide to the entire surface of the electrode substrate and drying it, 10 7 to the 11th power Ω / □ And a semiconductive layer that is less susceptible to humidity. As another specific method, a method using a solution containing an ion conductive polymer as a semiconductive paint as described in claim 12 can be mentioned. Examples of the ion conductive polymer include a polymer having a quaternary ammonium salt in the molecular structure. The quaternary ammonium salt has four alkyl groups bonded to the central ammonia atom, and has a positive charge as a whole. Since it has a structure in which anions such as chlorine ions are ion-bonded therewith, it has an ionic conductivity and therefore has a property of passing a slight charge. In addition, since the quaternary ammonium salt having ionic conductivity is included in the molecule in advance, it is not easily affected by humidity, and it is possible to ensure characteristics that allow a slight charge to pass even at low humidity. Have.

  In order to form an ion conductive polymer, there is a method of polymerizing a monomer having a quaternary ammonium salt and an unsaturated carbon bond in the molecular structure, but the quaternary ammonium salt and the unsaturated carbon bond are included in the molecular structure. Examples of the monomer having dimethylamino methacrylate include chloride salt. Then, an aqueous solution of a chloride salt of ruamino methacrylate is dissolved in alcohol, methyl methacrylate having a low molecular weight is added to secure film formability, and then a polymerization initiator such as azobisisobutyronitrile is added to conduct a polymerization reaction. By doing so, a polymer solution containing a quaternary ammonium salt can be obtained. In addition, it is possible to ensure adhesion to the coated surface by adding a polymer solution obtained by polymerizing a monomer having a carboxyl group such as acrylic acid and an unsaturated carbon bond in the molecule. . Moreover, since the coating film formed on the coating surface is made of a polymer having a large molecular weight, it exhibits water insolubility. The semiconductive layer formed by applying and drying the semiconductive paint thus prepared has a characteristic that it allows a slight charge to pass even at low humidity, and has water resistance without being peeled off from the coated surface. By applying such an ion conductive polymer to the surface of an insulating substrate and drying, a semiconductive layer having a surface resistivity of 10 7 to 11 11 Ω / □ and being hardly affected by humidity is obtained. It can be formed easily.

  Further, the dust collector according to claim 13 is characterized in that a resin film having a volume resistivity of 10 7-11 Ω · cm is provided on the surface of an insulating substrate as a semiconductive electrode plate. To do. Examples of the material of the film having a volume resistivity of 10 7 to 11 11 Ω · cm include nylon, polyvinylidene fluoride, or vinyl chloride or vinylidene chloride to which a plasticizer is added. Or a polymer with a highly water-absorbing amide bond such as nylon or polyether ester amide, a resin having a semiconductivity such as polyvinylidene fluoride or vinyl chloride or vinylidene chloride, and an insulating resin such as polypropylene, polyester or polystyrene. Examples thereof include a copolymer resin blended and copolymerized. As another example, a semiconductive material such as an inorganic component having a silanol group such as zeolite or a metal oxide such as zinc oxide is mixed with the above-described insulating resin and molded into a film. Such a resin film has a property of passing a slight amount of electric charge therein, and has a volume resistivity of 10 7 to the 11th power Ω · cm. By providing such a resin film on the surface of the insulating substrate by a method such as adhesion or welding, a semiconductive layer having a surface resistivity of 10 7-11 Ω / □ is provided on the surface of the insulating substrate. Is easily possible.

  The dust collector according to claim 14 is characterized in that a through hole is provided in the semiconductive electrode plate. Since the dust repellent electrode plate and the dust collecting electrode plate are alternately stacked in the dust collecting part, in order to provide a uniform electric field between the dust repellent electrode plate and the dust collecting electrode plate, The charge on the back should have a similar distribution. By providing a through hole in the semiconductive electrode plate, it is possible to apply a uniform charge to both the front and back surfaces of the semiconductive electrode plate through the wall surface of the through hole, and between the dust repellent electrode plate and the dust collecting electrode plate. A uniform electric field can be easily provided.

  The dust collector according to claim 15 is characterized in that the wall surface of the through hole is made conductive. By imparting conductivity to the wall surface of the through-hole, it is possible to make the charges applied to the front and back surfaces of the semiconductive electrode plate more uniform.

  The dust collecting apparatus according to claim 16 is characterized in that the insulating substrate is a resin plate in which a resin material is filled with short glass fibers and mica and extruded and subjected to a heat lamination press. Since the surface of the semiconductive electrode plate is semiconductive, it is necessary to have a structure in which the dust repellent electrode plate and the dust collecting electrode plate do not come into contact with a spacer or the like. In the case of contact, the dust repulsion electrode plate and the dust collection electrode plate are at the same potential at the contact location, and the electric field is weakened and the dust collection efficiency is reduced. Therefore, it is necessary that the semiconductive electrode plate is not greatly bent and that there is no large warp from the beginning. That is, the electrode plate itself needs to have high strength and flatness. Resin material is filled with short glass fibers and mica and subjected to heat lamination press after extrusion molding to obtain a resin plate having high strength and high flatness. By using such a resin plate as an electrode plate, an electrode plate Can be suppressed.

  The dust collecting device according to claim 17 is characterized in that the dust repellent electrode plate and the dust collecting electrode plate are connected by an insulator provided outside the frame. It is necessary to provide a space for passing air between the dust repellent electrode plate and the dust collecting electrode plate. However, if a spacer is provided by bridging contact between the dust repellent electrode plate and the dust collecting electrode plate for this purpose, charge movement occurs at the contact portion, and the surface potential is lowered around the contact portion. Is weakened. For this reason, the dust collection performance is reduced. Therefore, the dust repellent electrode plate and the dust collecting electrode plate are connected only by the insulator provided on the outside of the frame, that is, the surface of each of the dust repellent electrode plate and the dust collecting electrode plate is made by the insulator provided on the outside of the frame. By adopting a structure in which a constant space is maintained without contact at all, the surface potential does not decrease due to contact with the surface of the dust repellent electrode plate, and the electric field is kept constant. For this reason, it becomes possible to obtain high dust collection performance. Specifically, as described in claim 18, each of the dust repellent electrode plate and the dust collecting electrode plate is provided with a current-carrying through hole and a space insulating through hole, and the dust repellent electrode plate and the conductive material are inserted while inserting a conductive shaft. A cylindrical spacer, a dust collecting electrode plate, and a conductive cylindrical spacer are provided in this order.

  The shaft was inserted in the order of the space-insulating through hole of the dust repellent electrode plate and the cylindrical spacer, the current-carrying through hole of the dust collecting electrode plate and the cylindrical spacer, and the dust repellent electrode plate and the dust collecting electrode plate were alternately stacked. Make a structure. The current-carrying through-hole is a through-hole having a size that is slightly larger than the shaft so that the shaft can enter and can contact the cylindrical spacer. On the other hand, since the voltage cannot be applied when the dust repellent electrode plate and the dust collecting electrode plate are in contact with each other, the outer diameter of the cylindrical spacer is used to prevent the space insulating through hole from contacting the shaft and the cylindrical spacer. Is bigger than. Since the dust repellent electrode plate cannot be supported as it is, the shaft is inserted in the same order using another shaft to support the electrode plate. At this time, the through hole of the dust repellent electrode plate is used as an energizing through hole, and conversely, a space insulating through hole is provided in the dust collecting electrode plate. Since each electrode plate cannot be firmly fixed in this state, it is desirable that the number of shafts that support each electrode plate is two or more, that is, a total of four or more. And the shaft which supports each electrode plate is connected and fixed using a lever. By adopting such a structure, it becomes possible to support and fix each electrode plate while providing a space without any contact between the surfaces of the dust repellent electrode plate and the dust collecting electrode plate.

  The dust collector according to claim 19 is provided with a through-hole and a space insulating through-hole in each of the dust repellent electrode plate and the dust-collecting electrode plate, and at the same time a hole having the same size as the energized through-hole. The cylindrical embossing with the electrode plate is provided integrally with the electrode plate, and the dust repellent electrode plate and the dust collecting electrode plate are alternately stacked while providing a space by inserting a conductive shaft into the current-carrying through hole. To do. By adopting such a structure, the dust repellent electrode plate and the dust collecting electrode plate can be stacked while providing a space by the cylindrical embossing provided integrally with the electrode plate without using a conductive cylindrical spacer. Is possible. The cylindrical emboss is provided integrally with the electrode plate, and its surface has semiconductivity. Therefore, electric charges are supplied to the electrode plate from the shaft having conductivity through the cylindrical emboss, and corona discharge is caused between the dust repellent electrode plate and the dust collecting electrode plate, and an electric field can be simultaneously provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Incidentally, these embodiments are merely examples, and the present invention is not limited to these embodiments.

(Embodiment 1)
FIG. 1 is a perspective view of a dust collector 4 in which dust repellent electrode plates 2 and dust collecting electrode plates 3 provided with a semiconductive layer 1 having a surface resistivity of 10 7 to 11 11 Ω / □ are alternately stacked. A front view is shown in FIG. Incidentally, in FIG. 2, the frame 19 is shown as having a box shape. However, in order to make the drawing easier to understand, FIG. 1 shows only the frame 19 on both sides where the insulator 20 is provided. As shown in FIGS. 1 and 2, the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are provided with a current-carrying through hole 5 and a space insulating through hole 6 while sandwiching a cylindrical spacer 7 as shown in FIG. The shaft 8 is fixed while being spaced apart by inserting the shaft 8. The cylindrical spacer 7 and the shaft 8 are made of a conductive material such as metal, and are connected to the shaft 8 by a high-voltage power source 9 so as to be semiconductive provided on the dust repellent electrode plate 2 and the dust collecting electrode plate 3 respectively. It is possible to apply different voltages to the layer 1, for example, -8 kV to the semiconductive layer 1 of the dust repellent electrode plate 2 and 0 kV to the semiconductive layer 1 of the dust collecting electrode plate. Therefore, an electric field is formed in the space 10 provided between the dust repellent electrode plate 2 and the dust collecting electrode plate 3. Air containing dust is introduced into the dust collector 4 in the direction indicated by the ventilation direction 11.

  Here, the structure of the dust repellent electrode plate 2 will be described. Incidentally, the structure of the dust collecting electrode plate 3 is substantially the same as that of the dust repellent electrode plate 2, and the only major difference is the positions of the energizing through hole 5 and the space insulating through hole 6. FIG. 4 shows a dust repellent electrode plate 2 having a slit 12 on the surface. An edge 13 having a corner is provided by the slit 12, and the electric field strength is increased at the edge 13, so that discharge occurs. Further, FIG. 5 shows the dust repulsive electrode plate 2 provided with the dotted conductive portions 14 on the surface. Charge is collected in the dot-like conductive portion 14, and since the diameter is small, the electric field strength is increased and discharge occurs. When the size of the dotted conductive portion 14 is about 1 to 3 mm in diameter, it is suitable for causing discharge. FIG. 6 shows the dust repulsion electrode plate 2 having a spine-like conductive portion 15 provided on the surface. Electric charges are collected in the spine-shaped conductive portion 15, and the electric field strength at the spine-shaped tip 16 is increased to cause discharge.

  The dust repellent electrode plate 2 shown in FIGS. 4, 5, and 6 is a semiconductive electrode plate in which the semiconductive layer 1 is provided on the surface of the insulating substrate 17. Therefore, it has a function of limiting the movement of electric charges on the surface, and the corona discharge that ionizes air instead of sparks by the action has a high electric field strength, that is, the edge 13 of the end face of the dust repellent electrode plate 2, the edge of the slit 13. Generated at the point-like conductive part 14 and the spine-like conductive part 15. Air is ionized by this corona discharge, and the ionized air is combined with dust to charge the dust. The charged dust is applied to the dust repulsion electrode plate 2 or the dust collection electrode plate 3 by a uniform electric field provided in the space 10. It moves to either side and adheres to the surface of the electrode plate and is collected. When -8 kV is applied to the dust repellent electrode plate 2 and 0 kV is applied to the dust collecting electrode plate 3, the dust is negatively charged and moves to the dust collecting electrode plate 3 and is collected on the surface of the dust collecting electrode plate 3. Is done. Further, as shown in FIGS. 4, 5, and 6, a current-carrying through hole 5 and a space insulating through hole 6 are provided. The current-carrying through hole 5 is sized so that the shaft 8 just enters and comes into contact with the cylindrical spacer 7, and is fixed and energized by the contact point with the cylindrical spacer 7. The space insulating through-hole 6 is sized so that the spatial distance from the cylindrical spacer 7 to which the dust collecting electrode plate 3 is fixed and energized is 15 mm or more as a guide.

  For example, if the outer diameter of the cylindrical spacer 7 is 14 mm, the diameter of the space insulation through-hole 6 is 44 mm or more. This assumes that the dust collecting electrode plate 3 is made of a conductive material such as metal, and considers that no spark is generated between the conductive cylindrical spacer 7 and the dust collecting electrode plate 3. It is a thing. By taking such a spatial distance, even if a potential difference of about 10 kV is generated, no spark is generated. If both the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are composed of semiconductive electrode plates, no spark is generated even if the spatial distance is 15 mm or less. Further, as a method of providing the semiconductive layer 1 on the surface of the insulating substrate 17, a semiconductive paint having a coating surface of 10 7 to the 11th power Ω / □ is applied and dried, or 10 7 to the 11th power. Examples thereof include a method of attaching a film having a volume resistivity of Ω · cm to the surface of the insulating substrate 17. The cylindrical spacer 7 is in contact with the shaft 8 connected to the high-voltage power source 9, and a charge corresponding to the applied voltage is generated from the contact portion with the cylindrical spacer 7 around the energizing through hole 5 through the cylindrical spacer. It is supplied to the semiconductive layer 1.

  Since the semiconductive layer 1 has a surface resistivity of 10 7-11 Ω / □, it has a function of suppressing rapid charge movement while uniformly distributing charges corresponding to the applied voltage. . Therefore, even if a state that becomes the base point of the spark is formed at a certain place such as when large dust adheres, the electric charge does not move abruptly, so that the generation of the spark can be prevented. That is, it is possible to distribute charges corresponding to the applied voltage and form a uniform electric field in the space 10 to obtain high dust collection performance and at the same time prevent sparking. In addition, as shown in FIGS. 4, 5 and 6, the dust repellent electrode plate is provided with a plurality of small charge equalizing through holes 18. The wall surface of the charge uniformizing through-hole 18 has a surface resistivity of 10 7 to 11th power Ω / □ or semiconductivity such as 10 1 to 4th power Ω / □, and a dust repellent electrode. The semiconductive layer 1 provided on the front and back of the plate 2 has a function of eliminating the charge bias and making it uniform. Even if a portion where the contact between the cylindrical spacer 7 and the current-carrying through hole 5 is deteriorated is generated, if the contact of the other portion is sufficient, the charge distribution of the front and back semiconductive layers 1 is made the same throughout that portion, and the space 10 It is possible to obtain a uniform electric field at.

  Further, as shown in FIG. 2, the dust collector has a structure in which the surfaces of the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are not in contact with each other by supporting the dust repellent electrode plate 2 with an insulator 20 provided outside the frame 19. It has become. That is, the surface potential does not decrease when the surfaces come into contact with each other, and a uniform and strong electric field is always formed in the space 10, so that high dust collection performance can be obtained while preventing sparks. It has become.

  In addition, although it demonstrated by the structure which uses the semiconductive electrode plate which provided the semiconductive layer 1 in the surface of the insulating board | substrate 17 as the dust repulsion electrode plate 2 and the dust collection electrode plate 3, originally the surface is 7-7. Even when a semiconductive electrode plate made of a material of 11 11 Ω / □ is used as the dust repulsion electrode plate 2 and the dust collection electrode plate 3, it is possible to obtain high dust collection performance while preventing sparks in the same manner. is there.

  Here, the dust collector shown in Embodiment 1 was actually created and the dust collection efficiency was measured. The semiconductive layer 1 having a low surface efficiency of 10 8 Ω / □ is obtained by applying and drying a semiconductive paint on the surface of the resin insulating substrate 17 in both the dust repellent electrode plate 2 and the dust collecting electrode plate 3. The provided semiconductive electrode plate was used. Moreover, the thing which does not provide the slit 12, the dotted | punctate electroconductive part 14, and the spine-like electroconductive part 15 was used. The corona discharge occurs at the edge 13 of the end face or the edge 13 of the space insulating through hole, and the dust is charged mainly by the corona discharge generated in this portion. The dust repulsion electrode plate 2 and the dust collection electrode plate 3 have a plate thickness of 0.8 mm, a ventilation direction size of 250 mm, and a height direction size of 80 mm. The dust repellent electrode plate 2 and the dust collecting electrode plate 3 created in this size were alternately stacked with a gap of 7 mm, to obtain a dust collector 4 having an opening size of 80 mm in height and 100 mm in width. Here, for comparison, a dust collecting apparatus in which the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are not a semiconductive electrode plate but a conductive metal plate was also prepared, and the dust collection efficiency of both was measured. The ventilation speed at the time of measurement was set to be 0.5 m with respect to the opening dimension. In addition, in order to obtain the dust collection efficiency, the number concentration of particles having a particle diameter of 0.3 μm or more contained in the air on the air inflow side and the air outflow side of the dust collector 4 is measured with a particle counter, and the dust collection efficiency is determined from the difference. Was calculated. The results are shown in Table 1.

  As can be seen from Table 1, in the dust collector 4 of the embodiment, the dust collecting electrode plate 3 is set to 0 kV, and 63% is applied to the dust repellent electrode plate 2 at -8 kV, and 87% is collected from -10 kV. It became dust efficiency. On the other hand, in the dust collector 4 of the comparative example using a metal plate as the dust repellent electrode plate 2 and the dust collecting electrode plate 3, when -8 kV is applied to the dust repellent electrode plate 2, the dust collection efficiency is 29% and -10 kV is applied. When this occurred, sparking occurred and voltage could not be applied. Thus, without providing a charging unit for charging the dust, high dust collection without generating sparks by using only the dust collecting device 4 composed of the dust repelling electrode plate 2 and the dust collecting electrode plate 3 using the semiconductive electrode plate. This verification revealed that it is possible to obtain efficiency.

(Embodiment 2)
FIG. 7 shows a front view of a dust collecting device 4 in which a dust repellent electrode plate 2 and a dust collecting electrode plate 3 in which a cylindrical emboss 21 is provided around the current-carrying through hole 5 are laminated. FIG. 8 shows a dust repellent electrode plate 2 in which a cylindrical emboss 21 is provided around the current-carrying through hole 5. Incidentally, the structure of the dust collecting electrode plate 3 is substantially the same as that of the dust repellent electrode plate 2, and the only major difference is the positions of the energizing through hole 5 and the space insulating through hole 6. As shown in FIG. 8, the cylindrical emboss 21 is provided integrally with the dust repellent electrode plate 2 around the energization through hole 5, and a through hole having the same diameter as the energization through hole 5 is provided at the center. Yes. For this reason, all the surfaces inside and outside the cylinder of the cylindrical emboss 21 are semiconductive.

  As shown in FIG. 7, the conductive shaft 8 is inserted into the energizing through hole 5 and the cylindrical emboss 21 of the dust repellent electrode plate 2, and then inserted into the space insulating through hole 6 of the dust collecting electrode plate 3. Further, the conductive cylinder is inserted into the space insulating through-hole 6 of the dust repellent electrode plate 2 using another shaft 8 and then inserted into the current-carrying through-hole 5 and the cylindrical emboss 21 of the dust collecting electrode plate 3. Even if the spacer 7 is not used, the dust repellent electrode plate 2 and the dust collecting electrode plate 3 can be alternately stacked while leaving a space. The shaft 8 is fixed by an insulator 20 provided outside the frame 19, and the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are connected only by the insulator 20. Therefore, a structure in which the dust repellent electrode plate 2 and the dust collecting electrode plate 3 are fixed without being brought into contact with a space is easily obtained. The surface of the cylindrical emboss 21 is semiconductive. The cylindrical emboss 21 is in contact with the conductive shaft 8 connected to the high voltage power source 9, and a predetermined voltage is applied from the shaft 8 to the surface of the dust repellent electrode plate 2 and the dust collecting electrode plate 3 through the cylindrical emboss 21. Is done. Therefore, even if there is no conductive cylindrical spacer 7, it is possible to provide a corona discharge between the dust repellent electrode plate 2 and the dust collecting electrode plate 3 and at the same time to provide an electric field, and the dust collector 4 having high dust collection efficiency is provided. Easy to get.

  Since the dust collector of the present invention can provide high dust collection performance without a charging part for charging dust and can prevent sparks, it has high dust collection performance and safety, and has a simple structure. Is useful as a dust collecting device mounted on a dust collecting device, for example, an oil mist dust collector in a factory, a domestic air cleaner, or an air supply type exhaust fan.

The perspective block diagram which shows the dust collector as described in Embodiment 1 of this invention. Front view of the dust collector Configuration diagram showing the cylindrical spacer Configuration diagram showing dust repellent electrode plate with slits Configuration diagram showing a dust repulsive electrode plate provided with a tie-like conductive part The block diagram which shows the dust repulsion electrode plate which provided the same spine-shaped electroconductive part Front configuration diagram showing the dust collector described in the second embodiment The block diagram which shows the dust repulsion electrode plate which provided the same cylindrical emboss Configuration diagram showing the dust collector described in the reference

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductive layer 2 Dust repulsion electrode plate 3 Dust collection electrode plate 4 Dust collector 5 Current-carrying through-hole 6 Spatial insulation through-hole 7 Cylindrical spacer 8 Shaft 9 High-voltage power supply 10 Space 11 Ventilation direction 12 Slit 13 Edge 14 Point-like conduction Part 15 Spinous conductive part 16 Spinal tip 17 Insulating substrate 18 Charge uniformizing through hole 19 Frame 20 Insulator 21 Cylindrical emboss

Claims (19)

In a dust collector that alternately stacks dust repellent electrode plates and dust collecting electrode plates while providing a space and applies different voltages to each electrode plate, at least one of the dust repellent electrode plate and the dust collecting electrode plate is It is a semiconductive electrode plate having a surface resistivity of 10 7 to 11 11 Ω / □, and discharges between the dust repellent electrode plate and the dust collecting electrode plate to charge and collect the dust. Dust collector. The dust collector according to claim 1, wherein at least one of the dust repellent electrode plate and the dust collecting electrode plate has an edge on the surface. The dust collector according to claim 1 or 2, wherein a slit is provided on at least one surface of the dust repellent electrode plate and the dust collecting electrode plate. 4. The dust collector according to any one of claims 1 to 3, wherein a dot-like conductive portion is provided on at least one surface of the dust repellent electrode plate and the dust collecting electrode plate. 4. The dust collector according to any one of 1 to 3, wherein a spine-like conductive portion is provided on at least one surface of the dust repellent electrode plate and the dust collecting electrode plate. The dust collector according to claim 4 or 5, wherein the conductive portion is provided by applying and drying an inorganic conductive paint. The dust collector according to any one of 1 to 6, wherein the semiconductive electrode plate is formed of a resin having semiconductivity. 8. The dust collector according to claim 7, wherein an ion conductive polymer is contained in the insulating resin. The semiconductive electrode plate is provided with a semiconductive layer having a surface resistivity of 10 7 to 11 Ω / □ on the surface of an insulating substrate. Dust collector. A semiconductive electrode plate is obtained by applying a semiconductive paint having a coated surface of 10 7 to 11 to 11 / Ω / □ on the surface of an insulating substrate and drying to provide a semiconductive layer. Item 10. The dust collector according to Item 9. 11. The dust collector according to claim 10, wherein a solution containing a semiconductive metal oxide is used as a semiconductive paint. The dust collector according to claim 10, wherein a solution containing an ion conductive polymer is used as a semiconductive paint. The dust collector according to claim 10, wherein a semiconductive electrode plate is formed by providing a resin film having a volume resistivity of 10 7-11 Ω · cm on the surface of an insulating substrate. The dust collector according to claim 1, wherein a through hole is provided in the semiconductive electrode plate. The dust collector according to claim 14, wherein the wall surface of the through hole is made conductive. The dust collector according to any one of claims 9 to 15, wherein the insulating substrate is a resin plate in which a resin material is filled with short glass fibers and mica and extruded and subjected to a heat lamination press. The dust collecting apparatus according to any one of claims 1 to 16, wherein the dust repellent electrode plate and the dust collecting electrode plate are connected by an insulator provided outside the frame. The dust repellent electrode plate and the dust collecting electrode plate are each provided with a current-carrying through hole and a space insulating through hole, and while inserting the conductive shaft, the dust repellent electrode plate and the conductive cylindrical spacer, the dust collecting electrode plate and the conductive electrode The dust collector according to claim 1, wherein the dust collector is provided in the order of a cylindrical spacer. The dust repellent electrode plate and the dust collecting electrode plate are each provided with a current-carrying hole and a space-insulating through-hole, and at the same time, a cylindrical emboss having a hole of the same size as the current-carrying through hole is integrated with the electrode plate. 18. The collector according to claim 1, wherein the dust repellent electrode plate and the dust collecting electrode plate are alternately stacked while providing a space by inserting a conductive shaft into the energizing through hole. Dust equipment.

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