JP2002018318A - Electric dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain a dust collecting performance at a high level with time by completely exfoliating the collected dust during operation, and to make puff inconspicuous by collecting the dust by any of electrode set in an electric dust collector in which a plural set of an electrode set composed of a dust collecting pole and a discharge pole are aligned side by side along a gaseous stream direction. SOLUTION: During operation, uncharged hammering, in which dust collecting poles 11 to 15 are hammered by a hammering device 20 in an uncharged state where charging to electrodes A1 to A4, B1 to B4, C1 to C4, D1 to D4 are stopped, is performed to electrode sets S1, S2, S3 in order for 5 to 30 minutes at every prescribed period. When collected dust on the dust collecting poles 11 to 15 is completely exfoliated in a minus electrode set to which uncharged hammering is performed for 5 to 30 minutes, the dust in a gaseous stream and the redispersed dust after exfoliation from the minus electrode pair are caught by other electrode set to which usual charging is applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric precipitator for collecting fine particulate matter in an inflowing gas. The present invention relates to an electric precipitator provided with a plurality of sets along the collecting line, and a hammering device for hammering out the particulate matter collected by the dust collecting electrode corresponding to the dust collecting electrode of each electrode set.

[0002]

2. Description of the Related Art An electrostatic precipitator includes a plate-shaped precipitating electrode extending in the flow direction of an inflowing gas and facing each other, and a discharge electrode disposed between the precipitating electrodes. For example, by charging a negative high-voltage DC voltage to the discharge electrode and grounding the dust collection electrode, corona discharge is performed from the discharge electrode, and the corona discharge causes the particulate matter in the inflowing gas to charge (negative ions) ) To collect at the dust collection electrode.

In such an electrostatic precipitator, the particulate matter (hereinafter referred to as "dust") collected at the precipitating electrode becomes thicker with time, and the dust collecting performance is reduced. It is equipped with a hammering device that hammers the dust collection electrode and separates the collected dust.

In recent years, as shown in FIG. 5, an electrode set S composed of a dust collection electrode 51 and a discharge electrode 52 has been developed in order to improve dust collection performance and respond to an increase in gas flow velocity.
1, S2, and S3 are arranged along the gas flow direction G (see FIG. 5).
There are known three sets of electric dust collectors arranged side by side.
Hereinafter, for convenience of description, the electric dust collector is referred to as a plurality of sets of side-by-side electric dust collectors. In this multiple-unit side-by-side electric precipitator, the hammer (not shown) is connected to each of the electrode sets S1, S
It is equipped corresponding to the dust collecting electrode 51 of S2 and S3.

[0005] In a plant equipped with such a plurality of sets of side-by-side electric precipitators, when the gas is ventilated and the operation of the electric precipitator is stopped, the hammering device is used to hammer the dust collecting poles of the electric precipitator. There is known a method in which the collected dust is completely peeled off by continuously hammering 51 and collected by a lower hopper to prevent a reduction in dust collecting performance. The hammering in the uncharged state as described above is intended to eliminate the electric suction of the dust collection electrode to the collected dust and to surely separate the collected dust.

As described above, if the dust collecting electrode 51 is continuously hammered by the hammering device when the plant is stopped, it is possible to completely separate the collected dust from the dust collecting electrode 51.
Since the plant is not shut down for a long period of time, the dust collecting pole hammer is executed by the hammer during the operation of the plant.

[0007] That is, in a plurality of sets of side-by-side electric precipitators, during operation (in a normal charged state), the electrode sets S1, S1
The so-called schedule hammering, in which hammering is performed once or several times for a predetermined short period (for example, 5 minutes) of S2 and S3 in a predetermined order, is adopted. Specifically, the schedule hammering means, for example, when the three sets of electric dust collectors shown in FIG. 5 are arranged side by side, for example, the first set (sequentially along the gas flow direction G). The dust collection electrode 51 of the first electrode set S1) is hammered once, for example,
For example, after 5 minutes, the dust collection electrode 51 of the second electrode set S2
Is hammered once, and after 5 minutes, the dust collecting electrode 51 of the third electrode set S2 is hammered once.

[0008]

However, in such a plurality of side-by-side electric precipitators employing such a schedule hammer, the electrode sets S1, S2, S3 are sufficiently charged and the collected dust is not collected. Is strongly attracted to the dust collecting electrode 51 and the hammer is performed once or several times for each of the electrode sets S1, S2, and S3. The collected dust remains on the dust collecting electrode 51, and especially in the case of highly adherent dust, the peeling is not sufficient, and the dust accumulation gradually increases due to the insufficient dust peeling (the previous hammering). Since the dust is not completely removed by the hammering, the collected dust between the previous hammering and the current hammering further adheres to the residual dust. Of dust collection performance) There is a problem that causes a deterioration.

Here, in order to enhance the separation of the collected dust,
During operation, it is conceivable to carry out so-called reduced output hammering, in which the amount of charge to the discharge electrode 52 is made lower than usual and the hammering device hammers the dust collecting electrode 51.
Since there is no change in the fact that the dust is sucked, the collected dust cannot be completely peeled off, causing the dust collecting performance to deteriorate with time in the same manner as described above.

Further, in order to further enhance the separation of the collected dust from the case of the reduced power hammering, the operation of the electric dust collecting device is temporarily stopped during operation and the hammering is performed by the hammering device. However, dust in the gas stream and dust separated and re-scattered by hammering will be released into the atmosphere from the chimney at the later stage, and puffs (visible smoke lump) will be noticeable. In addition, during this temporary stop, the electric dust collector does not function, so that the dust collecting efficiency is reduced.

The present invention has been made to solve such a problem, and an electric dust collector in which a plurality of electrode sets each including a dust collecting electrode and a discharge electrode are arranged in a line along the gas flow direction. In operation, the collected dust on the collecting electrode is completely separated during the operation, thereby enabling the dust collecting performance to be maintained at a high level over time, and thus completely separating the collected dust. An object of the present invention is to provide an electric precipitator capable of maintaining dust collection efficiency at a high level and making puffs inconspicuous.

[0012]

SUMMARY OF THE INVENTION An electric precipitator according to the present invention comprises a dust collecting electrode extending in the flow direction of an inflowing gas and arranged so as to face each other, and a dust collecting electrode arranged between the dust collecting electrodes. Electrode and a hammering device for hammering the dust collecting electrode, an electrode set comprising a dust collecting electrode and a discharge electrode, in an electric dust collecting device in which a plurality of sets are arranged side by side along the gas flow direction, During operation, uncharged hammering of the dust collection electrode by a hammering device in an uncharged state in which charging to the electrodes is stopped is sequentially performed for the electrode set for 5 minutes to 30 minutes at predetermined intervals. It is characterized by performing.

According to the electric precipitator thus constructed, in one electrode set in which uncharged hammering is performed for 5 to 30 minutes during operation, the collected dust of the precipitating electrode is reduced. At this time, in the other electrode set which is completely separated and is normally charged, dust in the gas flow and dust separated and re-scattered from one electrode set are collected, and this is collected to a predetermined level. Is repeated for the electrode set in each period.

Here, the reason why the uncharged hammering is performed for 5 minutes to 30 minutes is that if the time is less than 5 minutes, the collected dust on the dust collecting electrode is insufficiently separated, and if the time exceeds 30 minutes, the dust collecting electrode is not used. This is because, although the collected dust is sufficiently separated, an uncharged state in which dust is not collected is wastefully continued.

It is preferable that the uncharged hammer be performed on the electrode set in order of 5 to 30 minutes every hour as a predetermined period.

By setting the predetermined period to one hour as described above, it is possible to more reliably and sufficiently separate the collected dust from each of the electrode assembly dust collecting electrodes, and to reduce the frequency of the uncharged state in which the dust is not collected. Dust collection efficiency is optimized.

Here, when the electrode set other than the last part in the gas flow direction is hammered without charge, the separation dust generated from the dust collection electrode of the electrode set other than the last part is collected by the dust collection electrode of the electrode set downstream therefrom. The puff released to the atmosphere from the chimney at the subsequent stage is not noticeable because it is collected, but if the last electrode set is hit with a non-charged hammer, the debris generated from the dust collection electrode of the last electrode set Will be released into the atmosphere from the chimney, and puffs may be noticeable.

Therefore, for the electrode set at the rearmost part in the gas flow direction in the electrode set, instead of the uncharged hammer, a reduced output hammer for hammering at a charge rate lower than the normal charge rate is performed for 5 minutes to It is preferably carried out for 30 minutes.

[0019] Thus, the separation dust of the electrode set at the rearmost portion in the gas flow direction is reduced as compared with the case of uncharged hammering.

Here, the charge rate of the reduced power hammer is set to 5% to 2%.
It is preferably set to 0%.

This is because if the charge rate of the reduced power hammer is less than 5%, the amount of dust that separates from the dust collecting electrode and goes to the chimney at the subsequent stage is too large, while if it exceeds 20%, the dust collecting electrode This is because the collected dust tends to be electrically sucked too much.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram showing an electric precipitator according to the present invention. In the drawings, the same elements are denoted by the same reference numerals.

As shown in FIG. 1, the electrostatic precipitator 1 of the present embodiment includes dust collectors 11 to 15 extending along a flow direction G of a flowing gas in a predetermined casing (not shown).
Wire-shaped discharge electrodes A1 to A4, B1 to B4, and C1 are provided so as to face each other in a direction perpendicular to the gas flow direction G and are arranged in parallel along the gas flow direction G for each of these dust collection electrodes.
Sets S1, S2, S respectively provided with C4 to C4, D1 to D4
3 are arranged side by side along the gas flow direction G to form three sets of side-by-side electric precipitators (see FIG. 5).

In the three sets of side-by-side electric precipitators 1, FIG.
As shown in the figure, a hammering device 2 for hammering the dust collection electrodes 11 to 15
0 is provided for each of the electrode sets S1, S2, S3.

In each of the electrode sets S1, S2, S3, the dust collecting electrode 1
1 to 15 are grounded and discharge electrodes A1 to A4, B1 to B4,
C1 to C4 and D1 to D4 are connected to the power supply device 2. The power supply device 2 is a high-voltage DC power supply circuit, and an AC power supply A
C, the primary input side of which is connected to the transformer 3;
And a rectifier bridge circuit 4 connected to the secondary output of the rectifier and rectifying to a direct current. The transformer 3 is connected to the AC power supply AC via two control thyristors 6, and a control device for controlling the conduction angle of the control thyristor 6 is connected to the control thyristor 6. In this control device, since the charged state is slightly different in each of the electrode sets S1, S2, and S3, the control device 7a is used in the electrode set S1, the control device 7b is used in the electrode set S2, and the control device 7c is used in the electrode set S3.

The control devices 7a, 7b and 7c include discharge electrodes A
Voltage dividers 5 for detecting charging voltages for 1 to A4, B1 to B4, C1 to C4, and D1 to D4 are connected respectively.
The control devices 7a, 7b and 7c monitor the voltage detected by the voltage divider 5 and control the conduction angle of the control thyristor 6 so that the secondary output voltage (current) becomes an appropriate value.
Discharge electrodes A1 to A4, B1 to B4, C1 to C4, D1 to D
4 is supplied with a negative high voltage DC voltage. Thereby, discharge electrodes A1 to A4, B1 to B4, C1 to C4, D1 to D4,
Corona discharge is generated between the dust collecting electrodes 11 to 15 that are grounded, and charges (negative ions) are given to dust in the flowing gas to be collected by the dust collecting electrodes 11 to 15.

During operation, the control devices 7a, 7b, 7c control the discharge electrodes A1 to A4, B1 to B4, C1 to C4, D
The control thyristor 6 is controlled so that the uncharged state in which charging is stopped for 1 to D4 is sequentially performed for the electrode sets S1, S2, and S3 for 5 minutes to 15 minutes every hour. At this time, the dust collection electrodes 11 to 1 of the electrode set in an uncharged state
The drive of the hammer 20 corresponding to the electrode set in the uncharged state is controlled so as to continuously hammer 5 (the specific control thereof will be described later).

In addition, the last electrode set S3 in the gas flow direction G
The control device 7c controls the electrode set S3 so as to charge the electrode set S3 at a charging rate of 5% to 20% instead of uncharged during continuous hammering by the hammering device 20 for 5 to 15 minutes, which is sequentially rotated. The thyristor 6 is controlled.

Next, the hammer 20 will be described in detail. As shown in FIG. 1, the hammering device 20 includes each electrode set S1,
As shown in FIG. 2, the gas flow direction G of the reinforcing plate 26 below the dust collection electrodes 11 to 15 is installed corresponding to S2 and S3.
This is a so-called rear lateral hammering device for hammering the hammering seat 23 provided at the downstream end.

As shown in FIG. 2, the hammering device 20 rotates the hammering shaft 21 clockwise in the figure by driving a drive source (not shown) such as a motor.
Hammer 22 rotatably attached to the hammer shaft 2 by a fork end 24 and a pin 25.
In accordance with one rotation, it is pulled up to the highest point, falls by the action of gravity, and hammers the hammering seats 23 arranged near the lowest point.

As shown in FIG. 2, the hammer 22 installed in correspondence with each hammering seat 23 of the dust collecting poles 11 to 15 is used to hammer the dust collecting poles 11 to 15 sequentially. , May be provided at different angles with respect to the hammering shaft 21, and in order to hammer all the dust collecting poles 11 to 15 at the same time,
Each of them may be provided at the same angle with respect to the hammering shaft 21.

According to the three sets of side-by-side electric precipitators 1 configured as described above, when the operation is started, each electrode set S1,
S2, S3 discharge electrodes A1 to A4, B1 to B4, C1 to C
4, a corona discharge is generated between D1 to D4 and the dust collection electrodes 11 to 15, and dust in the gas flowing into the electrode sets S1, S
2 and S3 are collected by the dust collection electrodes 11 to 15, respectively.

As shown in FIG.
After 5 minutes, the control thyristor 6 of the first electrode set S1 is controlled, and the discharge electrodes A1 to A4, B1 to B4, C
Charging for 1 to C4 and D1 to D4 is suspended for 5 to 15 minutes, and the first electrode set S1 is kept uncharged during this time. At this time, the other electrode sets S2 and S3 are in normal operation, and are operating at the normal charge rate.

When the first electrode set S1 is in the uncharged state, the hammer 20 of the first electrode set S1 is controlled,
The dust collecting electrodes 11 to 15 of the first electrode set S1 are continuously hammered during this uncharged state (5 to 15 minutes) (FIG. 3).
).

5 minutes to 1 with respect to the first electrode set S1
By the continuous hammering in the uncharged state for 5 minutes, the dust collected by the dust collection electrodes 11 to 15 of the first electrode set S1 is changed to the dust collection electrode 1
All are peeled off without being sucked by 1 to 15.

Here, if the uncharged hammering is less than 5 minutes, the collected dust from the dust collecting electrodes 11 to 15 is not sufficiently separated, and
If it exceeds the limit, the uncharged state in which dust is not collected will be wastefully continued even though the collected dust on the dust collection electrodes 11 to 15 is sufficiently separated. For this reason, in this embodiment, the time of the uncharged hammer is set to 5 minutes to 15 minutes in order to optimize the dust collection efficiency.

Now, the dust collection electrodes 11 to 11 of the first electrode set S1 will be described.
The peeled dust peeled off from No. 15 is the second and third electrode sets S
It is collected again at S3. Further, since the first set of electrodes S1 is in an uncharged state, dust in the gas flow that has passed without being collected by the first set of electrodes S1 is also a second and third set of electrodes S2, Collected in S3. For this reason, dust is not emitted conspicuously from the chimney of the latter stage.

When the uncharged hammering of the first set of electrodes S1 is completed, the first set of electrodes S1 uses the dust collection electrodes 11 to 15 in a state in which no collected dust is attached to the first electrode set S1. Dust collection is resumed.

On the other hand, after the completion of the uncharged hammering of the first electrode set S1, the same period as described above, that is, 45 minutes to 55 minutes
After a lapse of minutes, the control thyristor 6 of the second electrode set S2 is controlled, and the discharge electrodes A1 to A4, B1 to B
4, C1 to C4, D1 to D4 are charged for 5 minutes to 15
Then, the second electrode set S2 is set in an uncharged state. At this time, the other electrode sets S1 and S3 are in normal operation.

When the second electrode set S2 is in an uncharged state, the hammer 20 of the second electrode set S2 is controlled,
The dust collection electrodes 11 to 15 of the second electrode set S2 are continuously hammered during this uncharged state (5 to 15 minutes) (FIG. 3).
).

5 minutes to 1 with respect to the second electrode set S2
By the continuous hammering in the uncharged state for 5 minutes, all the collected dust on the dust collection electrodes 11 to 15 of the second electrode set S2 is peeled off. The separated dust is collected again by the third electrode set S3. Further, dust in the gas is first discharged to the first electrode set S
The dust collected by the first electrode set S1 and passed without being collected by the first electrode set S1 passes through the second electrode set S2 in an uncharged state, but is collected by the third electrode set S3. Gathered. For this reason, dust is not emitted conspicuously from the chimney of the latter stage.

When the uncharged hammering of the second set of electrodes S2 is completed, the second set of electrodes S2 passes through the dust collecting electrodes 11 to 15 in a state where no collected dust adheres to the inside of the gas. Dust collection is resumed.

On the other hand, when 45 minutes to 55 minutes have passed since the end of the uncharged hammering of the second electrode set S2, the control of the electrode set S3 at the rearmost end (third set) in the gas flow direction G is performed. Thyristor 6 is controlled and discharge electrodes A1 to A4, B1 to B4,
C1 to C4, D1 to D4 have a charge rate of 5% to 20%, and
Charged for minutes to 15 minutes.

Here, in the present embodiment, there are two ON mountains,
The control thyristor 6 is controlled so that the number of OFF peaks is about 8 to 38. At this time, the other electrode sets S1,
S2 is during normal operation (operation at a normal charge rate).

When the third electrode set S3 is in a reduced output state (a charge rate state lower than the normal charge rate), the hammer 20 of the third electrode set S3 is controlled, and the third electrode set S3 is controlled. The dust collecting electrodes 11 to 15 of the electrode set S3 are continuously hammered during this reduced output state (5 minutes to 15 minutes) (see the hatched portion in FIG. 3).

5 minutes to 1 with respect to the third electrode set S3
By the reduced output hammering for 5 minutes, a smaller amount of dust collected on the dust collecting electrodes 11 to 15 of the third electrode set S3 is peeled off than in the case of the uncharged hammering. Since there is no electrode set downstream from this, this separated dust will be released into the atmosphere from the chimney in the subsequent stage, but since the amount is smaller than in the case of uncharged hammering, the dust It is not emitted noticeably from the chimney. The dust in the gas is
It is collected by the first and second electrode sets S1 and S2.

Here, the charge rate by the reduced power hammering is set to 5 to 2
The reason why 0% is set is that if it is less than 5%, the dust collection electrodes 11 to 11 are set.
The amount of dust coming off from the stack 15 and going to the chimney in the subsequent stage is too large, and the dust is emitted prominently from the chimney.
On the other hand, if it exceeds 20%, the collected dust is too much electrically attracted to the dust collecting electrodes 11 to 15, and the peeling effect is reduced.

When the reduced output hammering of the third set of electrodes S3 is completed, the third set of electrodes S3 has a normal charge rate at the dust collection electrodes 11 to 15 where some of the collected dust remains. In this state, dust collection in the gas is resumed.

Thereafter, these series of operations are repeated.

As described above, in the present embodiment, during operation, the uncharged hammer is performed for 5 minutes to 15 minutes, and the collected dust of the dust collection electrodes 11 to 15 is completely removed. It is possible to maintain the dust collection performance at a high level over time by the complete separation of the collected dust, and the complete separation of the collected dust is performed during operation. It is possible to maintain the dust collection efficiency at a high level. In addition, when performing uncharged hammering for 5 minutes to 15 minutes with one electrode set, the other electrode set that is normally charged is separated from dust in the gas flow and one electrode set. Then, the re-scattered dust is collected, making it possible to make the puff inconspicuous.

Further, the continuous hammering of each of the electrode sets S1, S2, S3 is performed every hour, so that the collected dust of each of the electrode set dust collecting electrodes is more reliably and sufficiently removed. The frequency of the uncharged state where dust collection is not performed is optimized for dust collection efficiency.

In addition, for the electrode set S3 at the rearmost part in the gas flow direction G, reduced power hammering is performed instead of uncharged hammering, in which the hammering is performed in a charged state of 5% to 20%. In addition, the separation dust of the electrode set S3, which is not collected downstream from this, is reduced as compared with the case of the uncharged hammering, so that the puff can be made inconspicuous.

Here, in order to confirm the above-mentioned effects, the present inventor examined the dust collection performance by controlling three sets of side-by-side electric precipitators under the conditions of Example 1 and Comparative Example 1. .

(Example 1) During operation, uncharged hammering is performed on the electrode set in order, every 5 to 15 minutes, every hour, and on the electrode set at the rearmost part in the gas flow direction G. In place of the uncharged hammer, a reduced output hammer of 5% to 20% is performed.

(Comparative Example 1) During operation, the same schedule hammer as described in the prior art is performed.

FIG. 4 is a diagram showing the change over time of the dust collection performance of the first embodiment in comparison with the first comparative example using the dust concentration as an index. The imaginary line indicates Comparative Example 1. The dust concentration was measured at the chimney inlet at the latter stage. Further, since a desulfurization device is interposed between the outlet of the electrostatic precipitator and the inlet of the chimney of Example 1 and Comparative Example 1, the dust concentration shown in FIG. It is lower than the dust concentration at the outlet of the dust collector.

As shown in FIG. 4, Comparative Example 1 indicated by a virtual line
In this case, dust collection performance deteriorates with time due to insufficient dust peeling, and about 10.0 to 11.0 mg / Nm ³ (O ₂ 6
%), But in Example 1 shown in the shaded area, dust was sufficiently peeled off, and there was almost no deterioration of dust collection performance over time, and about 6 mg / Nm.
It is stable at a dust level as low as ³ (6% O ₂ ).

That is, according to Example 1, it has been demonstrated that the dust collection performance is maintained at a high level over time and that the puff is made inconspicuous.

The above value of about 6 mg / Nm ³ (O ₂ 6%) is an average value including the dust concentration which temporarily rises during hammering. Incidentally, at the outlet of the electrostatic precipitator of Example 1, the average value of the dust concentration was 22 mg / Nm ³ (O ₂ 6%).
Met.

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 electrodes A1 to A4, B1 to Although B4, C1 to C4, and D1 to D4 are wire-shaped discharge electrodes, the shape of the discharge electrode is not limited to this, and may be, for example, a round wire, a barbed wire, a barbed wire, or the like. A flat discharge electrode or the like having a projection may be used.

The hammer 20 is not limited to the configuration shown in FIG. 2, but may be another type of hammer. Further, the hammering device 20 is not limited to the rear lateral hammering device that hammers the downstream end of the dust collecting electrodes 11 to 15 in the gas flow direction G. Front side hammering device for hammering the upstream end in direction G or dust collecting electrode 11
It may be an upper hammering device for hammering the upper part of No. 15.

Further, in the above-described embodiment, in order to make the puff inconspicuous, the reduced-power hammering is performed on the electrode set S3 at the rearmost portion in the gas flow direction G. If it is inconspicuous and satisfies the environmental standard value such as the dust guarantee value, it may be an uncharged hammer as in the case of the electrode sets S1 and S2 on the upstream side, or may be an instantaneous uncharged hammer in some cases. But it is good.

In the above-described embodiment, it is assumed that the functions (maintaining a high level of dust collecting performance and dust collecting efficiency and making the puff inconspicuous) are sufficiently exhibited, and three sets of electric dust collecting devices arranged side by side. Although the application to 1 is described, the invention can be similarly applied to an electric precipitator in which a plurality of sets other than three are arranged in parallel.

Further, in order to further enhance the effect of removing the collected dust from the dust collecting electrodes 11 to 15, it is preferable to perform the schedule hammering in a period other than the uncharged hammering and the reduced output hammering of the above embodiment. .

In the above-described embodiment, the separation of the collected dust from the electrode-collecting electrode is more reliably and sufficiently achieved, and the frequency of the uncharged state in which the dust is not collected is optimized for the efficiency of the dust collection. For this purpose, continuous hammering for each electrode set S1, S2, S3 for 5 minutes to 15 minutes is performed every hour,
It is not necessarily limited to one hour.

In the above embodiment, the continuous hammering time (uncharged hammering time) is set to 5 minutes to 15 minutes in order to optimize the dust collection efficiency. It is possible.

Furthermore, the order of hammering on the electrode sets S1, S2, S3 is not limited to the above embodiment.

[0068]

According to the present invention, there is provided an electric dust collecting apparatus comprising a plurality of electrode sets each comprising a dust collecting electrode and a discharge electrode arranged side by side in a gas flow direction. Uncharged hammering the dust collecting electrode by a hammering device in an uncharged state in which charging is stopped for the electrode set in order from 5 minutes to 30 minutes, so as to be performed at predetermined intervals, With one electrode set that performs uncharged hammering for 5 to 30 minutes, the collected dust on the dust collection electrode is completely peeled off, and at this time, with another electrode set that is normally charged, Since it is configured to collect dust in the gas flow and dust that has separated and re-scattered from one electrode set, the dust collection performance is improved over time by complete separation of the collected dust. At the same level, and complete removal of the collected dust during operation. It enables to maintain efficiency in the high level, and, it is possible to obscure the puff by collecting dust in one of the electrode pairs.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an electric precipitator according to the present invention.

FIG. 2 is a perspective view showing a hammering device included in the electric dust collecting device of FIG. 1 together with a dust collecting electrode.

FIG. 3 shows an uncharged hammer during operation by the hammer of FIG. 2,
It is explanatory drawing which shows the implementation interval of a reduced output hammer, implementation time, and implementation order.

FIG. 4 is a diagram showing the change over time of the dust collection performance of the electric dust collector of FIGS. 1 to 3 in comparison with the conventional technology using the dust concentration as an index.

FIG. 5 is a plan view showing a three-unit side-by-side electric precipitator in which three electrode sets each including a dust collecting electrode and a discharge electrode are juxtaposed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... 3 sets of parallel electric dust collection devices, 2 ... Power supply device, 5 ... Voltage divider, 6 ... Control thyristor, 7a, 7b, 7c ... Control device, 11-15 ... Dust collection electrode, 20 ... Hammering device , A1 to A
4, B1 to B4, C1 to C4, D1 to D4 ... discharge electrode, G
... gas flow direction, S1, S2, S3 ... electrode set.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F24F 7/00 F24F 7/00 B

Claims (4)

[Claims] 1. A dust collecting electrode extending in a flow direction of an inflowing gas and arranged to face each other, a discharge electrode arranged between the dust collecting electrodes, and a hammer for hammering the dust collecting electrode. A plurality of electrode sets each including the dust collecting electrode and the discharge electrode are arranged side by side along the flow direction of the gas, wherein the electrode is charged during operation. The uncharged hammer to hammer the dust collecting electrode by the hammer in an uncharged state to stop,
An electrostatic precipitator, which is applied to the electrode set for 5 to 30 minutes at predetermined intervals. 2. The electrostatic precipitator according to claim 1, wherein the uncharged hammer is performed on the electrode set sequentially for one hour as the predetermined period for 5 minutes to 30 minutes. apparatus. 3. A reduced output hammer for hammering at a charge rate lower than a normal charge rate, instead of the uncharged hammer, for the electrode set at the rearmost part in the gas flow direction in the electrode set. 5 minutes to 30
The electrostatic precipitator according to claim 1 or 2, wherein the operation is performed for a minute. 4. The charge rate of said reduced power hammering is 5% to 20%.
%. The electric precipitator according to claim 3, wherein