JP7127250B2 - Electrostatic precipitator - Google Patents

Description

TECHNICAL FIELD The present invention relates to an electrostatic precipitator, and more particularly to an electrostatic precipitator used in air conditioners or air cleaners.

Some electric dust collectors are equipped with a charging section that charges dust and dirt, and a dust collection section that collects charged dust and dirt. The dust collector has a plurality of sheet-like electrodes arranged in parallel, and applies a voltage between adjacent electrodes. As a result, an electrostatic field is generated between adjacent electrodes, and the electrostatic field attracts and collects dust. However, when discharge occurs between the electrodes, the potential difference between the electrodes decreases, and the dust collection performance also decreases accordingly. When the electrodes are made of metal, electrical discharge is more likely to occur from the electrodes, so abnormal electrical discharge occurs when dust bridges between the different electrodes. In order to avoid this, a method is known in which the electrodes are formed of a high-resistance conductive resin (see, for example, Patent Document 1).

FIG. 6(a) shows a high-voltage electrode 4b2 made of a conductive resin having a high resistance among the electrodes of the dust collecting portion. FIG. 6(b) is a cross-sectional view of the high-voltage electrode 4b2 taken along line AA. The high-voltage electrode 4b2 is provided with a high-voltage electrode segment 4b21 at one end on the left side in the drawing, which is in contact with a high-voltage supply terminal (not shown) to supply power to the high-voltage electrode 4b2. A current flows through the high-voltage electrode 4b2 due to the voltage supplied from the high-voltage electrode segment 4b21. Since the high-voltage electrode 4b2 has a high resistance, the current is minute. A notch portion 4b202 is provided in the vicinity of the high voltage electrode segment 4b21 of the high voltage electrode 4b2, and the case fixing rib 4b32 is arranged in this notch portion 4b202. The case fixing ribs 4b32 are provided on a case (not shown) of the dust collection section. By inserting the notch 4b202 into the case fixing rib 4b32, the high-voltage electrode 4b2 can be fixed to a case (not shown) of the dust collector. The width of the connection portion 4b200 formed by cutting the high voltage electrode 4b2 by the notch portion 4b202 is formed narrower than the other portions of the high voltage electrode 4b2. For this reason, the connecting portion 4b200 has a narrower path through which current flows than the other portions and has a high resistance. The current that has passed through the connecting portion 4b200 spreads over the surface of the high-voltage electrode 4b2. In addition, a plurality of notches are provided on the right side of the connection portion 4b200 in the drawing among the ends of the high-voltage electrode 4b2 in the short direction. A collecting electrode fixing rib 4b12 for holding a collecting electrode (not shown) in between is arranged in each notch so that the collecting electrode fixing rib 4b12 and the high voltage electrode 4b2 do not come into contact with each other. A portion (4b100) surrounded by a dotted line shown in FIG. 6 has a narrow path through which current flows, and has a higher resistance than other portions. Therefore, a voltage drop occurs in these high-resistance portions (4b100, 4b200), and the potential of the electrode sheet becomes lower as it separates from the high-voltage electrode segment 4b21 in the longitudinal direction of the high-voltage electrode 4b2. There is a problem that an electric field of the required magnitude cannot be generated between the collector electrode and the collector electrode.

JP-A-8-173847

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an electrostatic precipitator capable of suppressing a drop in the potential seen from the high-voltage electrode segment 4b21 on the surface of the high-voltage electrode 4b2 of the electrode sheet. The purpose is to

In order to achieve the above objects, the present invention is grasped by the following configurations.
(1) A first aspect of the present invention is provided with a charging section that charges dust by electric discharge, and a dust collecting section that collects the dust charged in the charging section by an electrostatic field, and the dust collecting section has a plurality of electrode sheets formed of a conductive resin having a resistance higher than that of metal, and an electrode fixing member for fixing the plurality of electrode sheets, wherein the plurality of electrode sheets are connected to a plurality of high voltage electrodes and a plurality of collecting electrodes, wherein the high voltage electrodes and the collecting electrodes are alternately arranged, and the electrode fixing member holds the plurality of high voltage electrodes arranged in parallel to each other. and a collecting electrode holding member that holds a plurality of the collecting electrodes arranged parallel to each other, wherein each of the plurality of high voltage electrodes has at least a region that contacts the collecting electrode holding member. is coated with an insulating material, and each of the plurality of collecting electrodes is coated with an insulating material at least in a region in contact with the high-voltage electrode holding member, and is formed at one end of the electrode sheet by folding the electrode sheet. An electrode strip is provided, and the width of the electrode sheet is equal to the width of the electrode strip.

Advantageous Effects of Invention According to the present invention, it is possible to provide an electrostatic precipitator capable of suppressing a decrease in electric potential seen from the dust collection part collection electrode segment.

1 is a schematic configuration diagram of an air cleaner according to an embodiment of the present invention; FIG. 1 is a configuration diagram of an electrostatic precipitator according to an embodiment of the present invention; FIG. It is a perspective view of the dust collector of the electrostatic precipitator according to the embodiment of the present invention. FIG. 4 is an assembly diagram of the electrode sheet of the dust collecting portion of the electrostatic precipitator according to the embodiment of the present invention; 1 is a perspective view of an electrode sheet of a dust collector of an electrostatic precipitator according to an embodiment of the present invention; FIG. FIG. 10 is a positional relationship diagram between an electrode sheet and a holding component in a dust collecting portion of a conventional electrostatic precipitator. It is a figure which shows an example of the positional relationship of the electrode sheet of the dust collection part of the electrostatic precipitator which concerns on embodiment of this invention, and a holding component. FIG. 5 is a diagram showing another example of the positional relationship between the electrode sheet and the holding component of the dust collecting portion of the electrostatic precipitator according to the embodiment of the present invention;

EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth "embodiment") for implementing this invention is demonstrated in detail based on an accompanying drawing. The same numbers are given to the same elements throughout the description of the embodiment.

(Air cleaner)
First, an overview of an air cleaner 1 according to the present embodiment will be described with reference to FIG. In the air purifier 1, large dust is removed from the air sucked from the suction port 2 by the pre-filter 3, fine dust is collected by the electrostatic precipitator 4, and odor-causing substances are adsorbed by the deodorizing filter 5. be. The air cleaned by this process is blown out from the outlet 8 by the fan 6 .

In addition to these, the air cleaner 1 is provided with a dust sensor 13 above the suction port 2, an operation display board 12 on the top surface of the air cleaner 1, and a power control board 9 below the fan 6. . In the vicinity of the electrostatic precipitator 4, a charging section high voltage power source 10 and a dust collecting section high voltage power source 11 are provided.

(electric dust collector)
Next, the structure of the electrostatic precipitator 4 will be described. The electric dust collector 4 has, as shown in FIG. 2, a charge section 4a and a dust collection section 4b. Large dust is removed from the air by the pre-filter 3. Then, the dust contained in the air from which the large dust has been removed is charged by the charging section 4a and collected by the dust collection section 4b. More specifically, the charge section 4a includes a discharge electrode 4a1 and a counter electrode 4a2, and the dust collection section 4b includes a collection electrode 4b1 (collector sheet) and a high-voltage electrode 4b2. The charged dust is collected by the collection electrode 4b1 of the dust collection portion 4b due to the electrostatic field generated between the collection electrode 4b1 of the dust collection portion 4b and the high voltage electrode 4b2 of the dust collection portion 4b. be done. In the following description, a combination of the collecting electrode 4b1 of the dust collecting portion 4b and the high voltage electrode 4b2 of the dust collecting portion 4b is called an electrode sheet. This electrode sheet is made of a plate-shaped, high-resistance conductive resin.

Here, when the charge section 4a and the dust collection section 4b are set as one set, an example is shown in which three sets are provided, but the number of sets is not limited to this. A high voltage is supplied from a high-voltage power supply 10 for charging parts to each of the charging parts 4a. A high voltage is supplied from one high-voltage power supply 11 for the dust collecting portion to the dust collecting portion 4b. The charging section high voltage power supply 10 and the dust collection section high voltage power supply 11 are controlled by a power control board 9. The power control board 9 includes charging section switches 9a1 and 9a2 for supplying/cutting off power to the charging section 4a. , 9a3, and a dust collector switch 9b for supplying/cutting off power to the dust collector 4b. The power control board 9 is connected to a commercial power supply 14 .

(Dust collector)
Next, the dust collector 4b of the electric dust collector 4 will be described. FIG. 3 shows the appearance of one dust collecting portion 4b. The dust collecting portion 4b is surrounded by a dust collecting portion case 4b3 and a dust collecting portion cover 4b4, in which collecting electrodes 4b1 and high-voltage electrodes 4b2 are alternately arranged. A separator 4b5 is provided on the front surface of the dust collection section case 4b3, and a high voltage supply terminal 4b6a and a ground terminal 4b6b are provided on both sides of the dust collection section cover 4b4 at both ends in the short direction.

The internal structure of the dust collecting portion 4b will be further described with reference to the exploded view of FIG. As shown in FIG. 4, a dust collecting portion case guide 4b31 is provided inside the dust collecting portion case 4b3. A spacer 4b7 is arranged between both ends of the collecting electrode 4b1 and the high-voltage electrode 4b2 to maintain a constant gap between the two electrodes, and the spacer 4b7 is fitted in the dust collecting portion case guide 4b31. Collection electrodes 4b1 and high-voltage electrodes 4b2 are alternately arranged below dust collection section cover 4b4 with spacers 4b7 interposed therebetween. Three separators 4b5 are inserted between the collection electrode 4b1 and the high-voltage electrode 4b2 in order to keep the distance between the electrodes constant and to increase the structural strength.

(Electrode sheet <collection electrode of dust collection part, high voltage electrode of dust collection part>)
The collecting electrode 4b1 and the high-voltage electrode 4b2 of the dust collecting portion 4b according to this embodiment are configured as follows. In the following, the high-voltage electrode 4b2 will be described as a representative. FIG. 5 shows the positional relationship between the high voltage electrode 4b2 and the high voltage supply terminal 4b7 according to this embodiment. The high-voltage electrode segment 4b21 is formed by bending the high-voltage electrode 4b2 while keeping the width of the high-voltage electrode 4b2, and the high-voltage electrode segment 4b21 is in surface contact with the high-voltage supply terminal 4b7. Here, the width (height in the drawing) of the high voltage supply terminal 4b7 is not limited to the illustrated one, and may be the same as the width W1 (height in the drawing) of the high voltage electrode segment 4b21 of the high voltage electrode 4b2. .

Here, the positional relationship in plan view between the electrode sheet and the holding component that holds the electrode sheet will be described. First, the related art will be described with reference to FIG. As shown in FIG. 6, the high-voltage electrode 4b2 of the conventional dust collecting portion 4b has a connecting portion 4b200 extending toward one end (the left end in the drawing) of the high-voltage electrode 4b2. A high-voltage electrode segment 4b21 is formed by bending the high-voltage electrode 4b2 by 90° on the left side of the connecting portion 4b200 in the figure. The high voltage electrode 4b2 is fixed to a high voltage fixing rib 4b22 as a holding component. A collecting electrode fixing rib 4b12 for fixing the collecting electrode 4b1 (not shown) is arranged between the two high voltage fixing ribs 4b22. A notch portion 4b201 is provided in the high-voltage electrode 4b2 so that the collection electrode fixing rib 4b12 does not come into contact with the high-voltage electrode 4b2 in order to ensure insulation. A notch portion 4b202 is provided in the vicinity of the high voltage electrode segment 4b21 of the high voltage electrode 4b2, and the case fixing rib 4b32 is arranged in the notch portion 4b202. The case fixing ribs 4b32 are provided on a case (not shown) of the dust collection section. By inserting the notch 4b202 into the case fixing rib 4b32, the high-voltage electrode 4b2 can be fixed to a case (not shown) of the dust collector.

In such a configuration, as shown in FIG. 6, the connecting portion 4b200 indicated by the dotted line on the left side of the drawing has a path through which current flows narrower than the width W2 of the high-voltage electrode 4b2, and the wide portion of the high-voltage electrode 4b2. higher resistance than

On the other hand, the high-voltage electrode 4b2 of the dust collecting portion 4b according to the present embodiment will be described with reference to FIGS. 7 and 8. FIG. FIG. 7(a) shows the high-voltage electrode 4b2 of the dust collecting portion 4b. FIG. 7(b) is a sectional view of the high-voltage electrode 4b2 cut along the line BB. First, as shown in FIG. 7, the high-voltage electrode 4b2 is fixed by being inserted into the U-shaped holding portion 4b22a at the tip of the collecting electrode rib 4b12 in addition to the high-voltage electrode fixing rib 4b22. Therefore, the high-voltage electrode 4b2 is not provided with the connection portion 4b200 and the notch portion 4b201 unlike the conventional art. The periphery (inside the dotted line) in contact with the collecting electrode fixing rib 4b12 is an insulating covering area 4b205 covered with an insulating material. The high-voltage electrode 4b2 is composed of a rectangular flat plate, and a high-voltage electrode segment 4b21 formed by bending one end (the left end in the figure) of the high-voltage electrode 4b2 by 90° is brought into contact with the high-voltage supply terminal 4b7 (see FIGS. 4 and 5). ). The width W1 of the high voltage electrode 4b2 on the other end side opposite to the one end side where the high voltage electrode segment 4b21 is located is equal to or greater than the width W3 of the high voltage electrode segment 4b21.

Next, as shown in FIG. 8, the high-voltage electrode 4b2 of the dust collecting portion 4b is provided with an insulating covering area 4b205 in which the area (inside the dotted line) other than the high-voltage electrode segment 4b21 is covered with an insulating material. Other points are the same as the high voltage electrode 4b2 shown in FIG.

By coating the outside of the high-voltage electrode 4b2 with an insulating material in this manner, it is not necessary to avoid contact with the collecting electrode fixing rib 4b12, which is the holding member of the collecting electrode 4b1, and thus the notch causing high resistance. There is no need to provide the portion 4b201. As shown in FIG. 7, this coating is in contact with an electrode fixing rib having a polarity different from that of the high voltage electrode 4b2 (high voltage electrode fixing rib 4b22 for the collecting electrode 4b1 and collecting electrode fixing rib 4b12 for the high voltage electrode 4b2). You can go only partly. Also, as shown in FIG. 8, the collecting electrode 4b1 contacts all parts other than the collecting electrode segment 4b11 which contacts the ground terminal 1b6, and the high voltage electrode 4b2 contacts the high voltage supply terminal 4b7. All portions other than the high-voltage electrode segment 4b21 may be covered.

Here, the voltage drop of the high voltage electrode 4b2 shown in FIGS. 6 and 8 is compared as follows. In the high-voltage electrode 4b2 of the conventional dust collection part 4b shown in FIG. Assuming that a leak current of 0.01 μA flows through the other end portion 4b2b of the high-voltage electrode on the side, the voltage drop at the connecting portion 4b200 is 100 GΩ*0.01 μA=1 kV. Therefore, the potential at the connection point between the connecting portion 4b200 and the other end portion 4b2b of the high-voltage electrode among the surfaces contributing to dust collection is 5 kV-1 kV=4 kV. Furthermore, the width of the high-voltage electrode 4b2 is narrowed even at the cutout portion 4b201, and a voltage drop occurs, so that the potential of the electrode sheet becomes lower as the high-voltage electrode 4b2 moves away from the high-voltage electrode segment 4b21 in the longitudinal direction.

On the other hand, as shown in FIG. 8, the potential at the end position of the electric field plane that contributes to dust collection when the connecting portion 4b200 is eliminated and the sheet width of the high-voltage electrode 4b2 is made uniform will be examined. If the electrical resistance of the high voltage electrode 4b2 in contact with the high voltage supply terminal 4b7 is 10 GΩ, the voltage drop is 10 GΩ*0.01 μA=0.1 kV. Therefore, the potential on the surface contributing to dust collection is 5 kV-0.1 kV=4.9 kV. In this way, since the potential drop of the high-voltage electrode 4b2 can be minimized, the drop in dust collection performance can be minimized. Further, since the width of the high-voltage electrode 4b2 is uniform, a necessary potential can be secured between the high-voltage electrode 4b2 and the collecting electrode over the entire surface of the high-voltage electrode 4b2.

(Effect of Embodiment)
With the configuration as described above, the present embodiment has the following effects.
(1) The width of the electrode sheet (collection electrode 4b1 of the dust collection portion, high voltage electrode 4b2 of the dust collection portion) is constant, and the entire width is in contact with the high voltage supply terminal 4b7. Therefore, no large voltage drop occurs. As a result, it is possible to suppress a decrease in potential when viewed from the dust collecting portion collecting electrode segment 4b11 or the dust collecting portion high voltage electrode segment 4b21, and to generate a necessary electric field.
(2) Since the electrode sheet (dust collecting part collecting electrode 4b1, dust collecting part high voltage electrode 4b2) other than the dust collecting part collecting electrode segment 4b11 or the dust collecting part high voltage electrode segment 4b21 is covered with an insulating member, It is possible to suppress electric discharge at the dust collecting part.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications, Change is possible.

REFERENCE SIGNS LIST 1 air purifier 2 suction port 3 prefilter 4 electric dust collector 4a charge section 4a1 charge section discharge electrode 4b2 charge section counter electrode 4b dust collection section 4b1 dust collection section collection electrode (electrode sheet)
4b100...High resistance portion 4b101...Notch (of background art)
4b105 -- Insulating coating region 4b11 -- Dust collection part collection electrode piece 4b12 -- Collection electrode fixing rib 4b2 -- Dust collection part high voltage electrode (electrode sheet)
4b200 ... connection part (background art)
4b21 High voltage electrode piece 4b22 High voltage electrode fixing rib 4b3 Dust collecting case sheet fixing rib 4b300 Current path 4b301 High resistance area 4b5 Separator 4b6 High voltage supply terminal 5 Deodorizing filter 6 Fan 7 Fan motor 8 Air outlet 9 Power supply control board 9a1 to 9a3 Charging section switch 9b Dust collecting section switch 10 Charging section high voltage power supply 11 Dust collecting section high voltage power supply 12 Operation display board 13 Dust sensor 14 … commercial electrodes

Claims (3)

a charging unit that charges dust by discharging;
a dust collection unit that collects the dust charged in the charging unit by an electrostatic field,
The dust collecting part has a plurality of electrode sheets made of a conductive resin having a resistance higher than that of metal, and an electrode fixing member for fixing the plurality of electrode sheets,
The plurality of electrode sheets includes a plurality of high-voltage electrodes and a plurality of collection electrodes, the high-voltage electrodes and the collection electrodes are alternately arranged,
The electrode fixing member includes a high-voltage electrode holding member that holds the plurality of high-voltage electrodes arranged parallel to each other, and a collection electrode holding member that holds the plurality of collection electrodes arranged parallel to each other. and
each of the plurality of high-voltage electrodes is coated with an insulating material at least in a region in contact with the collecting electrode holding member;
each of the plurality of collecting electrodes is coated with an insulating material at least in a region in contact with the high-voltage electrode holding member;
An electrode piece formed by bending the electrode sheet is provided at one end of the electrode sheet,
An electrostatic precipitator, wherein the width of the electrode sheet is equal to the width of the electrode piece. The high-voltage electrode holding member is characterized in that a holding portion into which the collecting electrode is inserted is formed, and a holding portion into which the high-voltage electrode is inserted is formed in the collecting electrode holding member. The electrostatic precipitator according to claim 1. The electrostatic precipitator according to claim 1 or 2, wherein the at least one electrode fixing member is arranged in contact with the electrode piece.

Images