JP2018140346A - Electric dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric dust collector which enlarges the surface of an electrode where air flows while securing insulation.SOLUTION: An electric dust collector 1 comprises: a charging part; and a dust collecting part. The dust collecting part comprises: a tabular high voltage electrode plate 8; a tabular collection electrode plate 11; a rib 142 for the high voltage electrode plate; and a rib 141 for the collection electrode plate. The high voltage electrode plate and the collection electrode plate are alternatively parallely arranged while a surface of the high voltage electrode plate faces a surface of the collection electrode plate. The high voltage electrode plate is fixed to the rib for the high voltage electrode plate and includes a first notch part Ca to avoid contacting with the rib for the collection electrode plate. The collection electrode plate is fixed to the rib for the collection electrode plate and includes a second notch part Cb to avoid contacting with the rib for the high voltage electrode plate. A corner part in an opening side of at least one of the first notch part Ca and the second notch part Cb is formed to be a round shape, and at least one of the corresponding rib for the collection electrode plate and the rib for the high voltage electrode plate is formed along the round shape of the corner part.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an electric dust collector, and more particularly to an electric dust collector used for an air conditioner or an air purifier.

  2. Description of the Related Art Conventionally, an air conditioner or an air purifier is provided with an electric dust collector including a charging unit that charges dust or dust and a dust collection unit that collects charged dust or dust. In general, a plurality of rectangular sheet-like electrodes are arranged facing each other in the dust collection part, and by this arrangement, electrostatic fields are formed between the electrodes to collect dust and dirt. . The housing of the dust collecting portion is provided with a rib that is fixed with an electrode interposed therebetween, and this rib fixes one of the high-voltage side electrode and the ground-side electrode. The electrodes are provided with notches so as not to contact the ribs in order to ensure insulation between the electrodes having different polarities.

  However, since the corners of the notches are sharp, the electric field concentrates on the corners, and there is a problem that the potential of the electrode is lowered and the dust collection performance is lowered due to excessive discharge with respect to the ribs.

  In order to solve this problem, for example, a technique is disclosed in which the corners of the electrodes are formed in a curved shape, and the electric field is not concentrated on the corners to make it difficult to discharge (for example, Patent Document 1). reference).

  However, if both ends of the cut-out electrode are curved, air flows along the surface of the electrode, so that there is a problem that the proportion of air flowing on the electrode is reduced.

JP-A-5-329398

  The present invention has been made in view of the above problems, and aims to provide an electrostatic precipitator that ensures insulation and increases the surface area of the electrode through which air passes. To do.

The present invention is grasped by the following composition in order to achieve the above-mentioned object.
(1) A first aspect of the present invention is an electrostatic precipitator, a charging unit that charges dust contained in the air, a dust collecting unit that collects dust charged by the charging unit, The dust collecting section includes a plate-shaped high-voltage electrode plate, a plate-shaped collection electrode plate, a high-voltage electrode plate rib, and a collection electrode plate rib, and the surface of the high-voltage electrode plate In order to avoid contact with the ribs for the collecting electrode plates and the high voltage electrode plates are fixed to the ribs for the high voltage electrode plates and alternately arranged in parallel with the surfaces of the collecting electrode plates facing each other A second notch for avoiding contact with the high-voltage electrode plate rib, and the collecting electrode plate is fixed to the collecting electrode plate rib. A corner portion on the opening side of at least one of the first cutout portion and the second cutout portion is rounded. Is characterized in that at least one of said collecting electrode plate rib corresponding to the high voltage electrode plate rib is formed along the rounded shape of the corner portion.

  According to the present invention, since the electrode of the dust collecting part does not cause a discharge and the air flows along the rib, the time for flowing on the surface of the electrode is lengthened, and dust can be collected as much as possible. A dust collector can be provided.

It is a perspective view which decomposes | disassembles and shows the electric dust collector which concerns on embodiment of this invention. It is a perspective view which shows the external appearance of the dust collection part which concerns on embodiment of this invention. It is a perspective view which shows the internal structure of the dust collection part which concerns on embodiment of this invention. It is sectional drawing which shows the relationship between the collector sheet and rib of the dust collecting part which concerns on embodiment of this invention, Comprising: (a) is the relationship between a collector sheet (high voltage electrode plate) and the rib for high voltage electrode plates, (b) ) Shows the relationship between the collector sheet (collecting electrode plate) and the collecting electrode plate rib. It is a top view which shows the collector sheet (high voltage electrode plate) of the dust collection part which concerns on the conventional electric dust collector. It is a top view which shows the collector sheet (high voltage electrode plate) of the dust collection part which concerns on embodiment of this invention. It is a graph explaining a discharge characteristic about the collector sheet (high voltage electrode plate) of the dust collection part in the electric dust collector which concerns on embodiment of this invention. It is a figure explaining the rib in the electric dust collector which concerns on embodiment of this invention, Comprising: (a) is a figure explaining the clearance gap between the notch of a collector sheet, and the conventional rib, (b) is a collector sheet It is a figure explaining the rib which eliminated the crevice between notches.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention (hereinafter referred to as “embodiments”) will be described in detail with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.

(Overall configuration of electric dust collector)
First, the overall configuration of the electrostatic precipitator 1 will be described with reference to FIG. As shown in FIG. 1, the outer case front surface portion 2 and the outer case rear surface portion 3 are joined, and the GND case 4 and the HV plate 6 as the charging portion 1A are sandwiched inside the front surface portion 5 of the inner case. Is arranged. In FIG. 1, the parts that should be inside the outer case front part 2 and the outer case rear part 3, the charging part 1 </ b> A and the dust collecting part 1 </ b> B are outside the outer case front part 2 and the outer case rear part 3 for convenience of explanation. However, it is actually housed inside the outer case front portion 2 and the outer case rear portion 3.

  A rib 14 is provided in the inner case back surface portion 7 so as to extend in the vertical direction, and an HV (Hi Voltage) sheet 8 (high voltage electrode plate) which is a collector sheet as the dust collecting portion 1B is provided as a rib for the high voltage electrode plate. 14a, the GND sheet 11 (collecting electrode plate) is fixed to the collecting electrode plate rib 14b. On the right side of the HV sheet 8 in the drawing, an HV electrode 9 and an HV electrode cover 10 are provided. On the left side of the GND sheet 11 in the figure, a GND electrode 12 and a GND electrode cover 13 are provided. In the following description, the rib 14 will be referred to as the rib 14, and the high-voltage electrode plate rib 14 a and the collecting electrode plate rib 14 b will be described individually. Note that an electrostatic force is formed between the HV sheet 8 and the GND sheet 11 by applying a voltage between the HV sheet 8 and the GND sheet 11. The collector sheet is formed in a plate shape.

  The ventilation direction is the direction from the outer case front surface portion 2 to the outer case rear surface portion 3. Particles such as dust contained in the air flowing into the electrostatic precipitator 1 are charged by a discharge between the GND plate 4 and the HV plate 6 disposed in the charging unit 1A. Then, the particles charged by the charging unit 1A are collected by the GND sheet 11 by the electrostatic force formed between the HV sheet 8 and the GND sheet 11 disposed in the dust collecting unit 1B.

  The dust collector 1B will be further described with reference to FIGS. 2, 3, and 4. FIG. FIG. 2 shows the appearance of the dust collecting unit 1B of the electric dust collector 1, and FIG. 3 shows the internal structure of the dust collecting unit 1B. As shown in FIG. 2, the dust collecting portion 1B is arranged such that the HV sheet 8 and the GND sheet 11 are arranged on the outer case back surface portion 3 so that the longitudinal directions thereof are in the left-right direction in the drawing, 8 surface 8b and the surface 11a of the GND sheet 11, and the surface 8a of the HV sheet 8 and the surface 11b of the GND sheet 11 are alternately laminated so as to face each other. When the outer case back surface portion 3 is removed, as shown in FIG. 3, a rib 14 is provided in the inside so as to protrude from the inner case back surface portion 7 to the front side in the figure.

  In the ribs 14, high-voltage electrode plate ribs 14 a for fixing the HV sheet 8 and collecting electrode plate ribs 14 b for fixing the GND sheet 11 are alternately arranged. 3 shows an example in which three collecting electrode plate ribs 14b are provided. The HV electrode 9 is in contact with the right end of the HV sheet 8 in the drawing, and the GND electrode 12 is in contact with the left end of the GND sheet 11 in the drawing.

  Here, the fixed relationship between the HV sheet 8 and the GND sheet 11 and the high-voltage electrode plate ribs 14a and the collecting electrode plate ribs 14b will be described with reference to FIG. FIG. 4A is a cross-sectional view of the high-voltage electrode plate rib 14a for fixing the HV sheet 8 cut in the vertical direction and viewed from the horizontal direction. FIG. 4B is a cross-sectional view of the collecting electrode plate rib 14b for fixing the GND sheet 11 when viewed in the left-right direction after being cut in the up-down direction. As shown in FIG. 4A, the HV sheet 8 is fixed by being inserted into the slit 14a1 of the rib 14a for the high-voltage electrode plate (shown by a solid line in the figure), and the GND sheet 11 is the second notch. Since the portion Cb does not contact the rib 14a, it is not fixed to the high-voltage electrode plate rib 14a (indicated by a broken line in the figure). On the other hand, as shown in FIG. 4B, the GND sheet 11 is fixed by being inserted into the slit 14b1 of the collecting electrode plate rib 14b (indicated by a solid line in the figure), and the HV sheet 8 is the first one. Since it is not in contact with the rib 14b by the notch portion Ca, it is not fixed to the collecting electrode plate rib 14b (indicated by a broken line in the figure). A structure in which each sheet is not fixed by the ribs 14 having different potential polarities will be described later.

(Collector sheet)
Next, the collector sheet 20 will be described in detail. The collector sheet 20 is a pair of an HV sheet 8 (high voltage electrode plate) and a GND sheet 11 (collecting electrode plate). The HV sheet 8 and the GND sheet 11 are both asymmetrical. Both shapes and sizes are the same, and they are arranged so as to face each other in an inverted form after the left and right sides are reversed. In the following description, each sheet is referred to as a “collector sheet” when collectively described, and is referred to as an “HV sheet” or “GND sheet” when individually described.

  FIG. 5 shows a conventional collector sheet 20. The collector sheet 20 is formed of a rectangular sheet, and notches C are provided on both sides of the sheet in the short direction to avoid contact with the ribs 14 having different polarities when attached to the electrostatic precipitator 1. It has been. Here, an example is shown in which four notches C are provided on one side in the short direction and three notches C on the other side. End portions (portions indicated by length L3) are provided at both ends of an adhering portion (portions indicated by length L2) to which much dust or dust adheres, and electrodes are provided at lower ends in the drawing. Is pasted.

  Here, as described above, the collector sheet 20 of the dust collector 1B of the two-stage electrostatic precipitator 1 collects dust by forming an electrostatic field, but the notch C of the collector sheet 20 is collected. When discharge occurs from the corners of the ribs 14 to the ribs 14, the sheet potential is lowered by the discharge current, and a predetermined electric field strength cannot be obtained, resulting in a problem that dust collection performance is deteriorated. On the other hand, in order to avoid discharge as shown in FIG. 6, there is a technique of forming a portion where the electric field of the collector sheet 20 is concentrated in an R shape (arc shape). The shape (arc shape) has been made.

  On the other hand, in order to ensure insulation between the HV sheet 8 and the GND sheet 11, notches C (first notch portion Ca and second notch portion Cb) are provided in both sheets. The HV sheet 8 is fixed to the high-voltage electrode plate rib 14a, and the GND sheet 11 is fixed to the collecting electrode plate rib 14b. Normally, the cross-sectional shapes of the high-voltage electrode plate rib 14a and the collecting electrode plate rib 14b are substantially rectangular.

  The R shape of the corner portion 21 of the notch C is more difficult to discharge as its curvature increases, but on the other hand, the area of the collector sheet 20 becomes smaller and an electric field is formed between the HV sheet 8 and the GND sheet 11. Area to be reduced.

  However, when the R shape is increased, the electrostatic precipitator 1 is increased in size, and the gap between the notch C and the rib 14 is also increased. As a result, the ratio of the air passing between the HV sheet 8 and the GND sheet 11 that passes through the space above and below the notch C where no electric field is generated increases. Will be reduced. Therefore, in the present embodiment, as shown in FIG. 6, the R shape of the opening of the notch C of the collector sheet 20 is increased, and the cross section of the rib 14 that fixes the collector sheet 20 as shown in FIG. By making the shape along the R shape of the opening of the notch C of the collector sheet 20, the dust collection performance is not deteriorated due to an increase in the ratio of passing through the portion without the electric field described above. It is what you want to do.

  First, with reference to FIG. 7, it will be described how the discharge current flowing at the time of discharge with respect to the rib 14 where the size of the opening of the notch C affects the dust collection performance is changed.

  About the influence of the magnitude | size of R of the opening part of the notch C, the test was done as follows. The collector sheet 20 subjected to the test is as follows. As the HV sheet 8, a sheet composed of 9 9 Ωcm of volume low efficiency ρv = 3 * 10 was prepared. The shape of the HV sheet 8 was a rectangular shape (long side: 84 mm, short side: 34 mm, thickness: 0.4 mm), and a protrusion for attaching an electrode was provided at one of the four corners. Then, a corner to be tested is provided at one corner opposite to the short side when viewed from the protrusion, and an insulator is provided so as to cover the two corners at the short side opposite to the long side when viewed from the protrusion and corner. A vinyl tape was attached.

  On the other hand, as the GND sheet 11, a sheet constituted by volume low efficiency ρv = 200 Ωcm was prepared. The shape of the GND sheet 11 is also a rectangular shape (long side 216 mm, short side 34 mm, thickness 0.4 mm), and a protrusion for attaching an electrode to one corner opposite to the HV sheet 8 among the four corners is provided. Provided. The GND sheet 11 was used without being processed and provided with a corner.

Using the HV sheet 8 and the GND sheet 11 prepared as described above, the test was performed according to the following procedure.
(1) The HV sheet 8 is disposed so that the corner 21 faces the long side of the GND sheet 11 at a distance of 2 mm. At this time, the vinyl tape of the HV sheet 8 faces the GND sheet 11.
(2) Electrodes are attached to the respective protrusions of the HV sheet 8 and the GND sheet 11, and a voltage is applied between both sheets by a high-voltage power source.
(3) The return current from the GND sheet 11 is measured in the current measurement mode of the insulation resistance meter.
(4) The applied voltage when the current changes greatly due to discharge is obtained.

The following measuring instruments were used.
・ High-voltage power supply: Made by Matsusada Precision (6 kV / 0.5 mA max), positive electrode, Vmonitor, input 24 VDC with Imonitor
・ Oscilloscope: DCS-1204E manufactured by Techio Technology
Current measurement: YHP insulation resistance meter high resistance meter 4329A

  Based on the above preparation, the change of the applied voltage Vi at which the discharge current i becomes 50 nA was measured by changing the R of the corner 21 provided on the HV sheet 8 in the range of 1 to 15 mm. The results are as shown in FIG. The conditions for the test are a temperature of 26 ° C. and a humidity of 50%.

  As shown in FIG. 7, as R increases, the applied voltage Vi for starting the discharge to the rib 14 increases. Compared to when R is 1 mm, the applied voltage Vi is about 1 kV when R is 7 mm. Can be raised. When R exceeds 10 mm, the applied voltage Vi becomes almost constant. As described above, the effect of increasing the applied voltage Vi is obtained sequentially from the case where R is 1 mm. From the viewpoint of obtaining a remarkable effect of increasing about 1 kV, R is preferably in the range of 7 mm to 10 mm.

  Next, the cross-sectional shape of the rib for fixing the collector sheet 20 will be described with reference to FIG. 8 and FIGS. 5 and 6 as appropriate.

The main specifications of the collector sheet 20 shown in FIG. 5 or 6 are as follows, for example. Of course, the present embodiment is not limited to these specifications.
-Overall length L1: 188mm
・ Rectangle length L2: 162mm
-Length L3 at both ends: 13mm
・ Width W1: 18.5mm
・ Pitch P between notches: 23 mm (× 6 pitch = 138 mm)
・ Notch width Cl: 6mm
・ Cut depth Cw: 7mm

When the collector sheet 20 is set in accordance with the above specifications, the opening R of the cutout portion C of the collector sheet 20 is set to 7 mm, for example, and the cross-sectional shape of the rib 14 is left as a rectangle, FIG. The area of the gap on one side between the hatched notch C and the rib 14 is 10.5 mm ² . Looking at the collector sheet 20 as a whole, 10.5 mm ² × 2 (both sides of the rib) × 7 (total number of notches) × 2 (a pair of the HV sheet 8 and the GND sheet 11) The total area of the gaps is 294 mm ² . Since the total effective sheet area of the collector sheet 20 is 2409 mm ² , the total area of the gaps corresponds to 12.2%.

  Here, as shown in FIG. 8 (b), if the cross-sectional shape of the rib 14 is formed in a shape along the shape of R7 mm of the notch C, the air that has passed through the portion without the electric field is absorbed by the rib 14. Since it is forcibly induced on the collector sheet 20 having an electric field, the dust collection performance can be increased.

  In addition, since the cross section of the rib 14 becomes large, the rigidity of the rib 14 is increased, and it is also possible to suppress a leakage current that occurs when the ribs are connected to maintain strength.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications may be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 1 ... Electric dust collector 1A ... Charging part 1B ... Dust collection part 2 ... Outer case front part 3 ... Outer case back part 4 ... GND plate (charge part)
5 ... Inner case front 6 ... HV plate (charged part)
7 ... Back side of the inner case 8 ... HV sheet (collector sheet; high-voltage electrode plate of the dust collector)
9 ... HV electrode 10 ... HV electrode cover 11 ... GND sheet (collector sheet; collection electrode plate of dust collecting part)
12 ... GND electrode 13 ... GND electrode cover 14 ... rib 14a ... high voltage electrode plate rib 14b ... collecting electrode plate rib C ... notch Cl ... notch width Cw ... notch depth R1 ... R shape (1 mm) )
R7 ... R shape (7mm)

Claims (1)

A charging unit for charging dust contained in the air;
A dust collecting unit for collecting dust charged by the charging unit,
The dust collecting section includes a plate-shaped high-voltage electrode plate, a plate-shaped collection electrode plate, a high-voltage electrode plate rib, and a collection electrode plate rib,
Alternately arranged in parallel with the surface of the high-voltage electrode plate and the surface of the collecting electrode plate facing each other,
The high-voltage electrode plate is fixed to the high-voltage electrode plate rib, and has a first notch for avoiding contact with the collecting electrode plate rib,
The collection electrode plate is fixed to the collection electrode plate rib, and has a second notch for avoiding contact with the high voltage electrode plate rib,
The corner portion on the opening side of at least one of the first cutout portion and the second cutout portion is formed in a round shape, and at least one of the corresponding collecting electrode plate rib and the corresponding high voltage electrode plate rib. Is formed so as to conform to the rounded shape of the corner portion.

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