JPH07313901A - Electrostatic dust collector - Google Patents

Abstract

PURPOSE:To enhance dust collection capacity by concentrating charge to a peak part to generate strong discharge, in an electrostatic dust collector wherein a discharge electrode part is inserted in a dust collection electrode composed of a square cylindrical body, by arranging the peak part to the region of the discharge electrode corresponding to the corner part of the dust collection electrode. CONSTITUTION:When an electrostatic dust collector 1 is operated, a fan 6 is operated and air containing mist or the like is introduced into an introducing chamber 2a from a suction port 4a and subsequently introduced into an electrostatic dust collection device 11 from a square pipe 12. At the same time, a PC electric field due to discharge is generated across an anode pin 17 and the square pipe 12. At this time, charge is conc. to the tip of the peak part 21 of a lower electrode part 18 in the lower discharge part of the electrostatic dust collection device 11 and a strong DC electric field is generated across the peak part 21 and the vicinity of the corner part 12b of the square pipe 12 corresponding thereto and a shower of the positive ion going toward the corner part 12b from the peak part 21 is generated. Therefore, mist or the like collides with the positive ion to be positively charded and adheres to the vicinity of the corner part 12b to be recovered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic precipitator for collecting vapor, smoke, mist and the like.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 8, a cylindrical electrostatic precipitator 51 has been proposed. This electrostatic dust collector 51
Is configured by inserting a cylindrical discharge electrode 53 charged to the positive electrode (+ pole) into a cylindrical dust collecting electrode 52 charged to the negative electrode (− pole). According to this electrostatic dust collector, an electric discharge is generated between the dust collecting electrode 52 and the discharge electrode 53, and vapor, smoke, mist, etc. contained in the air introduced into the dust collecting electrode 52 due to the discharge ( (Mist or the like) is charged to the + pole. Then, the mist or the like charged to the + pole moves to the dust collecting pole 52 side, adheres to the dust collecting pole 52, and is collected.

[0003]

However, when the electrostatic dust collector 51 collects dust, a uniform DC electric field due to discharge is generated between the dust collecting electrode 52 and the discharge electrode 53. Radial around the center of the. That is, since the outer surface of the discharge electrode 53 is formed by a uniform circular curved surface, the charge is uniformly dispersed on the outer surface 53a of the discharge electrode 53, and the dust collecting electrode 52 and the discharge electrode 53 are separated from each other. A uniform DC electric field is generated between them. Therefore, a discharge of an average magnitude is always generated between the discharge electrode 53 and the dust collecting electrode 52, and for example, the discharge electrode 5
There is a problem that the electric charge of 3 cannot be concentrated and a strong discharge cannot be generated. Therefore, there is a problem that the dust collection efficiency for collecting mist and the like is poor.

Therefore, as shown by the phantom line in FIG. 8, for example, a technique in which a needle member 54 is attached to the discharge electrode 53 in the radial direction and electric charges are concentrated by the needle member 54 to generate a strong discharge. Is proposed. In this case, due to this strong discharge, a large amount of mist or the like adheres to the vicinity of the portion of the inner peripheral surface 52a of the dust collecting electrode 52 that faces the needle member 54. However, the inner peripheral surface 52 on which a large amount of this mist adheres
The portion of a has the same shape as the portion of the other inner peripheral surface 52a and has a uniform circumferential surface. Therefore, the mist or the like adheres to the limit amount that can immediately attach the mist or the like. Will end up. When the mist or the like adheres to the limit amount, there is a problem that the intensity of the discharge is significantly weakened by the adhered mist or the like and the dust collection efficiency is deteriorated.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an electrostatic precipitator having a high dust collecting ability.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a discharge electrode is provided on a dust-collecting electrode which is formed of a rectangular cylindrical body whose both ends are open and whose inner contour is polygonal. An electrostatic precipitator in which one end of the prismatic cylindrical body serves as a suction portion and the other end serves as a discharge portion while being inserted, and the discharge electrode has a corner portion having an inner contour shape of the dust collecting electrode. The point is that the pointed portion is provided at the corresponding position.

The invention according to claim 2 is, in the invention according to claim 1, characterized in that the pointed portion is formed by notching the discharge electrode. The gist of the invention according to claim 3 is that in the invention according to claim 1 or 2, the pointed portion is provided near the suction portion.

A fourth aspect of the present invention is characterized in that, in the third aspect of the invention, the outer and inner contour shapes of the dust collecting electrode are square.

[0009]

Therefore, according to the first aspect of the present invention, the dust collecting electrode is sucked with air containing, for example, mist from the suction portion side, and the direct current is generated by the discharge generated between the discharge electrode and the dust collecting electrode. Depending on the field, the mist or the like adheres to the dust collecting electrode. And
Clean air from which mist and the like has been collected is discharged from the discharge portion. In this case, since the electric charge is concentrated on the tip of the discharge electrode and the distance from the corner of the dust collecting electrode is shortened, a DC electric field due to a stronger discharge is generated between the tip and the corner. The generated mist moves to the dust collecting electrode side according to the DC electric field, and is collected in the vicinity of the corner portion. Moreover,
Since the corner portion has a surface for adhering mist or the like on both sides of the top portion thereof, the dust collecting ability is improved.

According to the second aspect of the invention, the pointed portion is formed by notching the discharge electrode, so that it is easily formed. According to the invention as set forth in claim 3, the mist or the like sucked from the suction portion is generated by strong discharge near the suction portion,
Immediately, the potential on the discharge electrode side is charged. Then, the mist and the like adhere to the dust collecting electrode while being collected and are collected.

According to the invention of claim 4, since the outer and inner contours of the dust collecting electrode are square, the dust collecting electrode can be easily formed by bending a plate member such as a sheet metal, and a plurality of dust collecting electrodes can be formed. The outer surfaces of the poles are easily combined with each other to form an electrostatic precipitator with a desired dust collection capability.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
It will be described with reference to FIG. As shown in FIG. 1, the electrostatic precipitator 1 has an outer periphery formed of a box-shaped case 2 having a rectangular cross section and made of a conductor such as metal. A flat plate portion 3 extending inward is formed on the lower portion of the inner side surface of the case 2. An introduction chamber 2a for introducing air containing mist or the like is formed below the flat plate portion 3, and a collection chamber 2b for collecting mist or the like contained in the air is formed above the flat plate portion 3. A suction port 4a for sucking air containing mist and the like and a discharge port 4b for discharging the mist and the like collected by the dust collector 1 to the outside of the dust collector 1 are formed on the lower surface of the introduction chamber 2a. A discharge port 4c for discharging the air purified by the dust collector 1 is formed on the upper side surface of the collection chamber 2b.
Further, an opening (not shown) is formed on the upper surface of the recovery chamber 2b, and a lid B is attached to close the opening. Further, a flange portion 5 is formed at the tip of the suction port 4a so that it can be easily attached to various machines such as a cutting machine that produces mist.

A fan 6 is connected to the intake port 4a in the introduction chamber 2a. The fan 6 is attached to the lower surface of the introduction chamber 2a via an insulating member, and the fan 6 and the case 2 are held in an insulated state. A propeller (not shown) is provided in the fan 6, and an opening 6a is formed in the upper portion of the fan 6 so that the suction port 4a and the case 2 communicate with each other. That is, as the propeller rotates, air containing mist or the like is sucked into the suction port 4a, and the sucked air is introduced into the case 2 from the opening 6a via the fan 6.

A door portion 7 is formed on one side surface of the case 2, and the door portion 7 is rotatably provided around a hinge (not shown). An electrostatic precipitator 11 is arranged in the recovery chamber 2b. The electrostatic precipitator 11 is provided with a plurality of square pipes 12 made of a conductor such as an aluminum material and having a square cross section as a dust collecting electrode. (9 pieces) are combined in a square shape and are welded to each other. A plate material 13 is welded to the lower portion of the square pipes 12 combined in a square shape so as to surround the periphery of the combined square pipes 12. Then, the plate member 13 is fixed to the upper surface of the flat plate portion 3 via a seal member or an insulating member (not shown), so that the square pipe 12 is disposed in the recovery chamber 2b. At this time, this seal member can prevent air containing mist and the like from leaking from the fixing portion between the plate member 13 and the flat plate portion 3. Further, the square pipe 12 and the case 2 are reliably insulated by the insulating member. A power supply (not shown) is connected to the square pipe 12, and the negative power is charged by the power supply. The size of this square pipe 12 is □ 30 mm × 100 mm to 150 mm.
I am using mm.

A bracket 14 is provided on the upper portion of the square pipe 12.
Is attached to the upper part of the bracket 14, and a flat positive electrode plate 15 having a positive polarity is fixed to the upper part of the bracket 14. This +
Since the entire electrode electrode plate 15, including the upper and lower surfaces thereof, is covered with the insulator 16 made of nylon resin or the like, the square pipe 12 and the + electrode electrode plate 15 are reliably insulated. The + electrode plate 15 has
The positive electrode pin 17 is inserted as a plurality of discharge electrodes that are inserted. This + electrode pin 17 is a + electrode plate 1
Since it is disposed in contact with No. 5, it is charged to the + pole. Further, a square through hole (not shown) is formed in the + electrode plate 15. That is, air or the like from the square pipe 12 can be passed through this through hole. In this embodiment, a total of nine positive electrode pins 17 are arranged in the vertical direction and three in the horizontal direction, and are inserted into the square pipes 12. That is, the positive electrode pin 17 is covered by the inner surface of the square pipe 12. Then, the lower end of the + electrode pin 17 slightly projects downward from the lower surface of the square pipe 12. Further, the head portion 17a of the + electrode electrode pin 17 projects upward from the upper surface of the + electrode electrode plate 15, and the head portion 17a is covered with an insulator 16a made of the same material as the insulator 16. .

As shown in FIG. 2, the positive electrode pin 17 has an upper electrode portion 18 formed on the positive electrode pin 17.
And a lower electrode portion 19 formed at the bottom. The lower electrode portion 19 is formed from the lower end of the positive electrode pin 17 upward to a length of about 1/4 of the entire length. In this case, in the electrostatic precipitator 11, the section corresponding to the upper electrode section 18 is the upper discharge section, and the section corresponding to the lower electrode section 19 is the lower discharge section. Then, the mist and the like introduced into the introduction chamber 2a uses the lower end opening Ka of the square pipe 12 on the lower discharge portion side as a suction portion.
The mist and the like introduced into the square pipe 12 are discharged from the upper end opening Kb with the upper discharge opening side upper discharge opening Kb.

As shown in FIG. 3, the outer electrode shape of the upper electrode portion 18 of the positive electrode pin 17 is formed in a square shape. That is, it is formed in the same shape as the inner contour shape of the square pipe 12 covering the + electrode pin 17, that is, in a similar shape. The upper electrode portion 18 has a square whose outer contour is one side of about 5 mm to 8 mm. Then, each outer surface 18 of the upper electrode portion 18
The a and the inner surface 12a of each pipe 12 are arranged in parallel with each other, and the outer surface 18a of the upper electrode portion 18 and the inner surface 12a are held at a constant distance δ.

As shown in FIG. 4, the lower electrode portion 19 is formed with a notch 20 formed by notching each surface 17a of the positive electrode pin 17 having a square cross section. 90 ° at the corner of + electrode pin 17
A pointed portion 21 having a smaller angle is formed.

The notch 20 is formed in an isosceles triangular shape having the apex at the substantially central portion of the outer surface 17a and both corner portions. The pointed portion 21 is formed such that the slopes 20a of the cutout portions 20 located on both sides of the corner portion intersect each other. In this embodiment, the angle α located at the corner of the notch 20 is 15 °, and the angle of the corner of the pointed portion 21 of the + electrode electrode pin 17 (pointed angle).
β is set to 60 °.

Next, the operation and effect of the electrostatic precipitator constructed as described above will be described. When the electrostatic precipitator 1 is driven, the fan 6 is driven, and air containing mist and the like is introduced into the introduction chamber 2a in the electrostatic precipitator 1 through the suction port 4a. Then, the air introduced into the introduction chamber 2a is introduced into the electrostatic precipitator 11 from below the square pipe 12.

When the electrostatic precipitator 1 is driven, a DC electric field due to discharge is formed between the positive electrode pin 17 and the square pipe 12. At this time, in the lower discharge part of the electrostatic precipitator 11, electric charges are concentrated on the tip of the pointed part 21 of the lower electrode part 18,
The pointed head 21 and the square pipe 1 corresponding to the pointed head 21
A DC electric field is generated between the second corner portion 12b and the vicinity thereof by a strong discharge, and a shower of positive ions from the pointed portion 21 toward the corner portion 12b is generated. Then, the mist and the like are positively charged by colliding with positive ions, and are attached and collected near the corner portion 12b of the square pipe 12. That is,
The mist and the like adhere to the inner surfaces 12a located on both sides of the top of the corner near the corner.

The air that has passed through the lower discharge portion is further introduced into the upper discharge portion. In the upper discharge portion, the distance between the outer surface 18a of the upper electrode portion 18 and the inner surface 12a of the square pipe 12 is
It is held at a constant interval δ. Therefore, a uniform and stable DC electric field is generated over the entire length h of each side of the + electrode pin 17. Therefore, the mist etc. charged in the lower discharge part but not collected in the lower discharge part and introduced into the upper discharge part moves to the square pipe 12 side in a stable state according to the DC electric field in the upper discharge part. Then, it is attached to the square pipe 12 and collected. Also, the lower discharge part is not charged, and the mist and the like introduced into the upper discharge part is charged in this upper discharge part,
It moves to the side of the square pipe 12 in a stable state according to the DC electric field, adheres to the square pipe 12 and is collected.

Therefore, according to this embodiment, the square pipe 12
Since the pointed portion 21 is formed on the lower electrode portion 19 in correspondence with the corner portion 12b, a strong DC electric field can be generated by the pointed portion 21. And the square pipe 12
Since the mist or the like can be attached to the inner surfaces 12a located on both sides of the corner portion 12b, the dust collection efficiency can be increased. Further, the pointed portion 21 can be easily formed on the square pipe 17 by notching the positive electrode pin 17.

Since the pointed portion 21 is formed below the + electrode pin 17, the mist and the like introduced into the electrostatic precipitator 11 can be immediately positively charged. Therefore, the dust collection efficiency can be increased. Furthermore, the upper electrode part 1
In No. 8, since a stable DC electric field is generated, the mist etc. charged by this tip and introduced into the upper discharge part can be recovered in a stable state, and the dust collection efficiency can be further improved. it can.

Further, since the outer contour shape of the square pipe 12 is formed in a square shape, the outer surface 1 of the square pipe 12 is formed.
2a can be easily combined, and the electrostatic dust collector 11 having a desired dust collecting ability can be configured.

Further, the square pipe 12 can be easily formed by bending, for example, a sheet metal or the like, which saves labor and time for production and improves productivity. still,
The present invention is not limited to the above-described embodiments, but may be modified as appropriate without departing from the spirit of the invention and carried out as follows.

(1) In the above embodiment, the positive electrode pin 17
By forming a notch 20 having an isosceles triangular shape on the outer surface 17a, a pointed portion 21 was formed. As shown in FIG. 5, a trapezoidal notch 22 may form a pointed portion 23. In this case, the bevel 23a is formed by the slope 22a of the cutout 22, and the cutout 22 has
A parallel surface 22b parallel to the inner surface 12a of the square pipe 12 is formed. Therefore, a strong DC electric field is generated between the pointed portion 23 and the corner portion 12b of the square pipe 12, and a uniform and stable DC electric field is generated between the parallel surface 22b and the inner surface 12a of the square pipe 12. Therefore, in the lower discharge part, the mist or the like can be immediately positively charged by the strong DC electric field, and the mist or the like can be recovered in a stable state according to the stable DC electric field.

(2) In the above embodiment, the pointed angle β may be appropriately changed to a desired angle smaller than 90 ° depending on the recovery conditions such as mist. For example, a peak angle of 85
The angle may be set to °, 45 °, 30 °, 15 ° or the like.

(3) In the above embodiment, as shown in FIGS. 6 and 7, a needle-shaped pin material 25 as a pointed portion on the + electrode pin 24 on the cylinder corresponds to the corner portion 12b of the square pipe 12. You may attach it.

In this case, the pin material 25 is replaced with the positive electrode pin 24
It is possible to easily form the cusp and to improve the dust collection efficiency only by attaching it to. (4) In the above embodiment, the tip of the positive electrode pin 17 may be formed flush with each other without protruding from the lower end opening Ka of the square pipe 12. Further, the tip of the + electrode pin 17 may be located inside the square pipe 12.

(5) In the above embodiment, the electrostatic precipitator 11 is constituted by the set of square pipes 12 and the positive electrode pin 17.
May be configured. Moreover, the electrostatic dust collector 11 having a desired dust collecting capability may be configured by appropriately combining a desired number of square pipes 12 and inserting the positive electrode pin 17 into each square pipe 12. .

(6) In the above-described embodiment, the pointed portion 21 is formed in the section of about 1/4 of the entire length from the lower end of the + electrode electrode pin 17, but it is formed on the entire + electrode electrode pin 17. May be. Further, the pointed portion 21 may be formed in an appropriately desired section such as the upper portion or the middle portion of the + electrode pin 17.

(7) In the above embodiment, the notch 20 may be formed in the conical tip portion 17b (see FIG. 2) of the positive electrode pin 17. (8) In the above embodiment, in order to increase the surface area of the sloped surface 20a of the cutout portion 20, the sloped surface 20a may be subjected to surface treatment such as shot blasting. Further, the slope 20a may be knurled or the like. Similarly, the slope 20a may be formed in a pear-like shape. As described above, by increasing the surface area of the slope 20a of the cutout portion 20, the dust collecting capability of the electrostatic dust collector 11 can be improved.

The technical ideas other than the claims grasped in the above embodiment will be described below together with the effects. (1) The electrostatic precipitator according to claim 1, wherein the tip of the electrostatic precipitator comprises a needle-shaped pin material 25.

According to this electrostatic dust collector, the pointed portion can be easily formed and the dust collection efficiency can be improved. The term "square pipe" used in this specification is defined as follows.

"Square pipe" means a pipe material which has a polygonal inner shape and an outer contour shape and whose outer surfaces are overlapped with each other so that a plurality of pipe materials can be appropriately combined. For example, not only the pipe material having both the inner shape and the outer contour shape of the square shape shown in the above embodiment, but also the pipe material of various shapes such as a regular triangle, a rectangle, a rhombus, and a regular hexagon may be used.

[0037]

As described above in detail, according to the first aspect of the invention, by concentrating the electric charge on the tip, a strong discharge is generated between the tip and the corner of the dust collecting electrode. In addition, the mist that has moved to the vicinity of the corner of the dust collecting electrode due to this discharge can be attached to both sides of the corner of the dust collecting electrode, so that the dust collecting capability can be improved. . According to the invention described in claim 2, the pointed portion can be easily formed by notching the discharge electrode. According to the invention described in claim 3, since a strong discharge is generated near the suction part, the mist and the like introduced into the suction part can be immediately charged to the electric potential on the discharge electrode side, and the dust collecting capability can be improved. Can be improved. According to the invention as set forth in claim 4, since the outer and inner contour shapes of the dust collecting electrodes are square, it is possible to easily form by bending a plate member such as a metal plate, and at the same time, the outer surfaces of the plurality of dust collecting electrodes can be formed. Electrostatic precipitators that can be easily combined with each other and have a desired dust collecting capability can be configured.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an electrostatic precipitator in one embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing a state in which a positive electrode pin is inserted in a square pipe in one embodiment.

FIG. 3 is a cross-sectional view showing an upper discharge part in one embodiment.

FIG. 4 is a cross-sectional view showing a lower discharge part in one embodiment.

FIG. 5 is a cross-sectional view showing a lower discharge part in another example.

FIG. 6 is a partially cutaway perspective view showing a state in which a positive electrode pin is inserted into a square pipe in another example.

FIG. 7 is a cross-sectional view showing a lower discharge part in another example.

FIG. 8 is a sectional view showing an electrostatic dust collector in a conventional example.

[Explanation of symbols]

11 ... Electrostatic dust collector, 12 ... Square pipe as dust collecting electrode,
12b ... Corner portion, 17 ... + electrode electrode pin as discharge electrode, 21 ... Point of head, Ka ... Opening of lower end as suction portion,
Kb ... The upper end opening as a discharge part.

Claims (4)

[Claims] 1. A discharge electrode is inserted through a dust-collecting electrode which is open at both ends and has an inner contour shape of a polygonal prism, and one end of the prismatic cylinder serves as a suction part, and An electrostatic precipitator with an end serving as a discharge part, in which the discharge electrode is provided with a pointed head at a position corresponding to a corner of the inner contour shape of the precipitator. 2. The electrostatic precipitator according to claim 1, wherein the pointed portion is formed by cutting out a discharge electrode. 3. The electrostatic precipitator according to claim 1, wherein the pointed portion is provided near the suction portion. 4. The electrostatic precipitator according to claim 3, wherein the outer and inner contour shapes of the dust collector are square.