JP2001025682A - Electric precipitator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the dust collection performance of an eclectic precipitator having an electrification part and a collection part and to miniaturize the precipitator. SOLUTION: The interval D between the dust collection electrode 4 and discharge electrode 5 of an electrification part 2 is made approximately equal to the interval (d) between the dust collection electrode 6 and discharge electrode 7 of a collection part 3. In a post-stage of the electrodes 4, 5 of the electrification part 2, the electrodes 6, 7, whose polarity is the same with that of the electrodes 4, 5, of the collection part 3 are arranged to be separated from the electrodes 4, 5 and to be on a line so that the voltage gradient of one duct of the electrification part 2 and that of one duct of the collection part 3 in the post-stage corresponding to one duct of the electrification part 2 are in the same direction. Particles C charged by the electrification part 2 are moved in the collection part 3 without being inverted to be caught surely by the dust collection electrode of the dust collection part 3. The generation of corona discharge between the electrification part 2 and the dust collection part 3 is prevented even when the electrodes of the electrification part 2 and the electrodes of the dust collection part 3 are arranged closely.

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 fine particulate matter in an inflowing gas.

[0002]

2. Description of the Related Art For example, in a road tunnel, an electric precipitator for treating exhaust gas generated from a vehicle or the like is installed for the purpose of improving the visibility of a vehicle driver and environmental measures such as ventilation of air in the tunnel. You. As an electric precipitator adopted as this electric precipitator for tunnels, for example, the one described in JP-A-10-28897 is known.

As shown in FIG. 5, the electrostatic precipitator disclosed in this publication has a charging unit 22 and a collecting unit 2 disposed downstream of the charging unit 22 along the flow of exhaust gas flowing from inside the tunnel.
3 is a so-called two-stage type electric dust collector in which 3 is disposed.

[0004] In the charging section 22, plate-shaped dust collecting electrodes 24 extending in the gas flow direction B are arranged in parallel in a direction orthogonal to the gas flow direction B and face each other.
A flat discharge electrode 25 facing the dust collecting electrode 24 is disposed at the center between the two. Similarly, in the collecting part 23 in the latter stage, the plate-shaped dust collecting electrodes 26 are arranged side by side facing each other, and the plate-shaped discharge electrode 27 is arranged at the center between these dust collecting electrodes 26, 26. In addition, in another electric precipitator,
In some cases, a wire-shaped discharge electrode is arranged instead of the flat discharge electrode 25 of the charging unit 22.

The dust collecting electrode 24 of the charging unit 22 and the dust collecting electrode 26 of the collecting unit 23 are each grounded, and the discharge electrode 25 of the charging unit 22 and the discharge electrode 27 of the collecting unit 23 have, for example, a negative high voltage ( A positive high voltage may be used, but it is assumed negative for the sake of explanation). The particulate matter C in the gas is given a charge (negative ion) 9 by corona discharge generated in the charging unit 22, and the charged particulate matter C is charged by the action of the electrostatic field in the collection unit 23. The dust is collected by the dust collecting electrode 26 of the collecting unit 23.

Here, in this electric dust collector, from the viewpoint of reducing power consumption by improving discharge characteristics, etc.
As shown in FIG. 5, the electrode interval D between the collection electrode 24 and the discharge electrode 25 in the charging unit 22 and the collection electrode 26 in the collection unit 23
The distance d between the electrode and the discharge electrode 27 is different, and has a relationship of D> d.

[0007]

As described above, the discharge electrodes of the charging unit 22 and the collecting unit 23 are arranged such that the electrode of the collecting unit 23 is located after the electrode of the charging unit 22 in the relationship of D> d. When the dust collecting electrode is disposed, for example, as shown in FIG. 5, 1 is formed between the dust collecting electrode 24 and the discharge electrode 25 of the charging unit 22.
A plurality of ducts are formed in the collecting part 23 in the subsequent stage corresponding to one gas flow path (hereinafter, a gas flow path formed between the dust collection electrode and the discharge electrode is simply referred to as a duct). Therefore, a duct having a voltage gradient in the opposite direction to the voltage gradient of one duct of the charging unit 22 is generated in the duct of the collecting unit 23 in the subsequent stage corresponding to one duct of the charging unit 22.

Accordingly, the particulate matter C, which is negatively charged by the charging unit 22 and whose moving direction is determined by the voltage gradient of one duct of the charging unit 22, is transferred to the collection unit 23 having a voltage gradient in the opposite direction. When entering, the moving direction is reversed with the gas flow direction B as the center line due to the voltage gradient in the opposite direction. In other words, referring to FIG. 5 as an example, in FIG. 5, the particulate matter C that has proceeded obliquely downward and rightward is turned obliquely upward and proceeds obliquely upward.

For this reason, in the trapping section 23, the particulate matter C
Of the moving direction with the gas flow direction B as the center line,
There is a problem that the particulate matter C passes through before reaching the dust collection electrode 26, and the dust collection performance is reduced.

In particular, in recent years, in an electric dust collector for a tunnel, it is required to further increase the tunnel ventilation flow velocity (an average passage velocity in the electric dust collector is 9 m / s or more). If the moving direction of the particulate matter C is reversed with the gas flow direction B as the center line, the possibility of passing through the trapping portion is further increased.

Here, such a problem arises even in a two-stage type electrostatic precipitator having a relation of D <d, in which a duct having a voltage gradient in the opposite direction to the voltage gradient of one duct of the charging unit is formed.
Because it is located at a position corresponding to one duct of the charging unit,
Occurs similarly.

In FIG. 5, when the distance between the discharge electrode 25 of the charging unit 22 and the dust collection electrode 26 of the discharge electrode 23 immediately downstream of the discharge electrode 25 is small, the corona between the discharge electrode 25 and the dust collection electrode 26 becomes small. Since the discharge is generated, the corona discharge between the charging part 22 and the dust collecting electrode 24 is hindered. For this reason, in the electrostatic precipitator having the above configuration, the charging unit 2 and the collecting unit 3 need to be set apart from each other to some extent, which has been an obstacle to downsizing the device.

The present invention has been made to solve such a problem, and an object of the present invention is to provide an electric dust collecting apparatus capable of improving dust collecting performance and reducing the size.

[0014]

According to the present invention, there is provided an electrostatic precipitator for charging a particulate matter in an inflowing gas, and for collecting the charged particulate matter passing through the charging part. A charging unit, wherein the charging unit extends in the gas flow direction and is arranged so as to face each other, and a discharge electrode arranged substantially at the center between the dust collection electrodes. And a collection unit, wherein the collection unit extends in the gas flow direction and is arranged so as to face each other, and a plate-shaped discharge electrode arranged substantially at the center between the collection electrodes In the electrostatic precipitator provided with, the electrode spacing between the dust collection electrode and the discharge electrode is substantially the same between the charging unit and the collection unit, and the charging unit is disposed downstream of the charging unit electrode. The electrodes of the collecting section having the same polarity as the electrodes are arranged so as to be separated from the electrodes of the charging section and to be arranged in a line. Consisting of Te.

According to the electrostatic precipitator configured as described above, the voltage gradient of one duct of the charging unit and the voltage gradient of one duct of the subsequent collecting unit corresponding to one duct of the charging unit are in the same direction. , And the particulate matter charged by the charging unit is moved by the collection unit without reversing the moving direction, and is reliably collected by the dust collection electrode of the collection unit. Further, since the collecting unit electrode having the same polarity as that of the charging unit electrode is disposed downstream of the charging unit electrode, even if the charging unit electrode and the collecting unit electrode are arranged close to each other, the charging unit Corona discharge does not occur between the collector and the collector.

Here, the dust collection electrodes of the charging unit and the collection unit may be integrated.

In the case where such a configuration is adopted, since the dust collection electrodes of the charging unit and the collection unit are generally grounded together, there is no functional problem even if the above-mentioned dust collection electrodes are integrated. In addition, the number of parts can be reduced by adopting the configuration.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In each of the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a front view showing an electrostatic precipitator 1 according to an embodiment of the present invention, which is mainly a front view showing a charging section 2, FIG. 2 is a sectional view taken along line AA of FIG. FIG. 3 is a rear view of the electrostatic precipitator 1 of FIG. 1, which is a rear view mainly showing the collection unit 3. FIG. 4 is a plan explanatory view showing the operation of the electric precipitator 1 according to the embodiment. The electric dust collector 1 of the present embodiment is a tunnel electric dust collector used for a tunnel.

As shown in FIG. 1 to FIG.
Includes a box-shaped case 8 as a housing. In this case 8, a ventilation fan (not shown) is passed through a front side (FIG. 2).
A gas inlet 8a is formed at the front and a gas outlet 8b is formed at the rear in order to allow the exhaust gas flowing in from the left side) to pass therethrough.

Inside the case 8, as shown in FIG.
Along with the flow direction B of the gas flowing in from the gas inlet 8a, the charging unit 2 for providing an electric charge to the particulate matter in the gas is arranged, and the charging unit 2 is disposed downstream of the charging unit 2. A collecting unit 3 for collecting the particulate matter that has passed through and charged is disposed, and a charging unit 2 and a collecting unit 3 having the same configuration are further provided in a stage subsequent to the charging unit 2 and the collecting unit 3. You.

It should be noted that only the charging section 2 and the collecting section 3 are arranged, and the charging section 2 having a similar configuration is provided downstream of the collecting section 3.
And the collection part 3 may not be juxtaposed.

As shown in FIG. 1 and FIG.
A plurality of rectangular plate-shaped dust collecting electrodes 4 extending along the gas flow direction B are provided face-to-face in a direction perpendicular to the gas flow direction B (a direction perpendicular to the plane of FIG. 2). , 4 is provided with a rectangular flat discharge electrode 5 facing the dust collection electrode 4. In the discharge electrode 5 of the charging unit 2, a protrusion for generating corona discharge is arranged in parallel at least on the upstream end and the downstream end of the gas.

The dust collecting electrodes 4 and 4 are supported by a dust collecting electrode support fitting 12 penetrating through the dust collecting electrodes 4 and 4 to form a case 8.
Fixed to In the discharge electrode 5, the dust collecting electrode support bracket 12 is inserted through a large-diameter discharge electrode through hole 5 a formed in the discharge electrode 5, thereby ensuring insulation with the discharge electrode 5. Further, the discharge electrodes 5 and 5 are supported by a discharge electrode support fitting 13 penetrating the discharge electrodes 5 and 5 and the insulator 16
Is fixed to the case 8. This electrode support 1
In the dust collecting electrode 4, the large-diameter dust collecting electrode through hole 4 a formed in the dust collecting electrode 4 is inserted into the dust collecting electrode 4, thereby ensuring insulation from the dust collecting electrode 4.

As shown in FIGS. 2 and 3, the collection unit 3 also has a rectangular flat plate-shaped dust collection electrode 6 extending along the gas flow direction B, similar to the charging unit 2, and is orthogonal to the gas flow direction B. A plurality of substantially rectangular flat discharge electrodes 7 facing the dust collection electrode 6 are provided at the center between the dust collection electrodes 6, 6.

The dust collecting electrodes 6 and 6 are supported by a dust collecting electrode support 14 penetrating through the dust collecting electrodes 6 and 6, and
Fixed to In the discharge electrode 7, the dust collecting electrode support 14 is inserted through a large-diameter discharge electrode through hole 7a formed in the discharge electrode 7, thereby ensuring insulation with the discharge electrode 7. Further, the discharge electrodes 7 are supported by a discharge electrode support fitting 15 penetrating through the discharge electrodes 7, 7 and the insulator 17.
Is fixed to the case 8. This electrode support 1
The dust collection electrode 6 is inserted through a large-diameter dust collection electrode through hole 6 a formed in the dust collection electrode 6, thereby ensuring insulation with the dust collection electrode 6.

As shown in FIG. 2, the dust collecting electrode 4 of the charging unit 2 and the dust collecting electrode 6 of the collecting unit 3 are grounded, respectively.
A high-voltage DC power source 1 is connected to the discharge electrode 5 of the
0 and 11 are respectively connected to apply a high negative DC voltage. As a result, in the charging section 2, the dust collecting electrode 4 and the discharge electrode 5
And a corona discharge is generated between the dust collection electrode 6 and the discharge electrode 7 in the collection unit 3 to form an electrostatic field as a uniform electric field.

In this embodiment, the high-voltage DC power supply 11
Is higher than the high-voltage DC power supply 10, and the potential of the collection unit 3 is higher than that of the charging unit 2. However, the voltage may be opposite to the above, or may be the same. Although the high-voltage DC power supply has two power supplies, depending on the plate size and discharge characteristics,
It may be a power supply.

Further, in the present embodiment, in particular, the electrode interval between the dust collection electrode and the discharge electrode is made the same between the charging section 2 and the collection section 3 and at the subsequent stage of the electrode of the charging section 2. The electrodes of the collection unit 3 having the same polarity as the electrodes of the charging unit 2 are arranged so as to be separated from the electrodes of the charging unit 2 and arranged in a line.

That is, as shown in FIG. 4, the electrode interval D between the collection electrode 4 of the charging unit 2 and the discharge electrode 5 is determined by the distance between the collection electrode 6 and the discharge electrode 7 of the collection unit 3. At the same stage as the electrode interval d, the dust collection electrode of the collection unit 3 is arranged at a stage subsequent to the collection electrode 4 of the charging unit 2 so as to be separated from the collection electrode 4 of the charging unit 2 and arranged in a line. 6 and the discharge electrode 5 of the charging unit 2
In the subsequent stage, the discharge electrodes 7 of the collection unit 3 are arranged so as to be separated from the discharge electrodes 5 of the charging unit 2 and arranged in a line.

Therefore, the voltage gradient of one duct (one gas flow path formed between the dust collection electrode and the discharge electrode) of the charging unit 2 and the subsequent collecting unit corresponding to one duct of the charging unit 2 3 in 1
The voltage gradient of the duct is a voltage gradient in the same direction.

Next, the operation of the thus-configured electric dust collecting apparatus 1 will be described. The operation is started and the charging unit 2
When the high voltage of the high-voltage DC power supply 10 is applied to the discharge electrode 5 of the collector, a corona discharge occurs between the dust collecting electrode 4 and the discharge electrode 5 in the charging unit 2, and the high-voltage DC is applied to the discharge electrode 7 of the collection unit 3. When a high voltage of the power supply 11 is applied, the collection unit 3 collects the dust collection electrode 6 and the discharge electrode 7.
And an electrostatic field is formed.

As shown in FIG. 4, the particulate matter C in the gas passes through the charging section 2 and is given a charge (negative ion) 9 as shown in FIG. Of 1
It enters one duct of the collecting part 3 in the latter stage corresponding to the duct.

An electrostatic field is formed between the collection electrode 6 and the discharge electrode 7 of the collection unit 3, and the particulate matter C is applied to the collection electrode 6 of the collection unit 3 by the action of the electrostatic field. Although it moves, as described above, the voltage gradient of one duct of the charging unit 2 and the voltage gradient of one duct of the subsequent collecting unit 3 corresponding to one duct of the charging unit 2 are set to be the same voltage gradient. Therefore, as shown in FIG. 4, the moving direction of the charged particulate matter C is not reversed in the collection unit 3 (the moving direction of the particulate matter C is the gas flow direction B as the center line). Move without being inverted). For this reason, the charged particulate matter C is collected by the collection unit 3
The dust collection electrode 6 is surely collected.

That is, in the present embodiment, since the moving direction of the particulate matter C is not reversed in the trapping section 3, even if the gas is at a high speed (9 m / s or more) as in a tunnel, the movement is not affected. The particulate matter C is surely collected by the dust collecting electrode 6 of the collecting part 3, so that the dust collecting performance can be improved.

Further, since the electrode of the collecting section 3 having the same polarity as the electrode of the charging section 2 is disposed at the subsequent stage of the electrode of the charging section 2, the electrode of the charging section 2 and the electrode of the collecting section 3 are arranged. Are arranged so that corona discharge does not occur between the charging unit 2 and the collection unit 3. For this reason, the apparatus can be shortened in the gas flow direction, and the size can be reduced.

Further, since the charging unit 2 and the collection unit 3 are further provided at the subsequent stage of the collection unit 3, the length of the dust collection electrode 6 of the collection unit 3 in the gas flow direction B is reduced. You can do it. As a result, the particulate matter C charged by the charging unit 2 is unlikely to lose its charge in the middle of the collection unit 3, and the dust collection performance can be further improved. Further, in the charging section 2 in the subsequent stage, the particulate matter C rescattered from the collecting section 3 in the previous stage is recharged and collected again in the collecting section 3 in the subsequent stage, so that the particulate matter C is prevented from being re-scattered. The effect is achieved.

As described above, the present invention has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment. For example, in the above embodiment, the discharge electrode 5 of the charging unit 2 is used. Although the discharge electrode is a flat discharge electrode, the discharge electrode of the charging unit 2 is disposed at the center between the dust collecting electrodes 6 and 6 and extends in the vertical direction, and is disposed at a predetermined distance from each other along the gas flow direction B. The present invention can be similarly applied to an electrostatic precipitator having a wire-shaped discharge electrode.

In the above embodiment, the charging unit 2
Although the dust collecting electrode 4 and the dust collecting electrode 6 of the collection unit 3 are separate bodies, the dust collecting electrodes 4 and 6 may be integrated. Even if the dust collecting electrodes are integrated as described above, there is no functional problem because the dust collecting electrodes of the charging unit 2 and the collecting unit 3 are both grounded.
In addition, since the number of parts is reduced by adopting the configuration, cost reduction can be achieved.

Further, in the above-described embodiment, the electric dust collecting device is used as a tunnel electric dust collecting device because it is particularly effective to apply it to a tunnel in which a high speed of the tunnel ventilation flow is required. It is also possible to adopt it as an air purifier or for removing exhaust dust of a diesel engine.

[0041]

According to the electric dust collecting apparatus of the present invention, the distance between the dust collecting electrode and the discharge electrode is substantially the same between the charging section and the collecting section, and at the subsequent stage of the charging section electrode. By arranging the electrodes of the collection unit having the same polarity as the electrodes of the charging unit so as to be separated from the electrodes of the charging unit and arranged in a line, one of the charging units
The voltage gradient of the duct and the voltage gradient of one duct of the subsequent collecting unit corresponding to one duct of the charging unit are set to have the same voltage gradient, and the particulate matter charged by the charging unit is moved by the collecting unit. By moving without reversing the direction, the dust is collected by the dust collecting electrode of the collecting part, and even if the electrode of the charging part and the electrode of the collecting part are arranged close to each other, the charging part and the collecting part Since the configuration is such that corona discharge does not occur between the first and second embodiments, the dust collection performance can be improved and the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a front view showing an electrostatic precipitator according to an embodiment of the present invention, and is a front view mainly showing a charging unit.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a rear view of the electric precipitator of FIG. 1, mainly showing a collecting portion.

FIG. 4 is an explanatory plan view illustrating an operation of the electric precipitator according to the embodiment;

FIG. 5 is an explanatory plan view showing a problem of the electric precipitator according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric dust collector for tunnels (electric dust collector), 2 ... Charging part, 3 ... Collection part, 4 ... Dust collection electrode of charging part, 5 ... Electrode discharge electrode of charging part, 6 ... Collection of collection part Dust electrode, 7 ... discharge electrode of collection part, 9
... Negative ions, B ... Gas flow direction, C ... Particles, D ... Electrode spacing between the collection electrode and discharge electrode at the charging unit, d ... Dust separation between the collection electrode and discharge electrode at the collection unit Electrode spacing between.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tsukasa Harazaki 1-1-1, Yatocho, Tanashi-shi, Tokyo Sumitomo Heavy Industries, Ltd. Inside Tanashi Works (72) Inventor Mitsuhiro Mieno 63rd Yugigaoka, Hiratsuka-shi, Kanagawa No. 30 Sumitomo Heavy Industries Machinery Co., Ltd. Hiratsuka Works No. 1 F-term in EBARA CORPORATION (reference) 4D054 AA07 BA02 BB05 BB12 BC03 BC18 BC21

Claims (2)

[Claims] 1. A charging unit for providing a charge to particulate matter in an inflowing gas, and a collecting unit for collecting the charged particulate matter passing through the charging unit; Is
A flat-shaped dust collecting electrode extending in the gas flow direction and arranged to face each other, and a discharge electrode arranged at substantially the center between the dust collecting electrodes, and the collecting unit includes In an electric precipitator including a flat dust collecting electrode extending in the gas flow direction and arranged to face each other, and a flat discharge electrode arranged substantially at the center between the dust collecting electrodes, The electrode interval between the dust collection electrode and the discharge electrode is made substantially the same between the charging unit and the collection unit, and the same electrode as the electrode of the charging unit is provided downstream of the electrode of the charging unit. An electrostatic precipitator, wherein the electrodes of the collection section are spaced from the electrodes of the charging section and arranged in a line. 2. The electric dust collecting apparatus according to claim 1, wherein the dust collecting electrodes of the charging unit and the collecting unit are integrated.