JP2011194375A - Wet electric dust collector and dust collection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To more properly prevent a fire from breaking out.SOLUTION: A dust collecting electrode 22 is a square tubular dust collecting electrode composed of a plurality of units of aggregates, with a square tube having a square opening as a unit. As not shown in the figure, but a discharge electrode is housed in each of the plurality of units comprising the dust collecting electrode 22. In a region formed by being surrounded with the plurality of units comprising the dust collecting electrode 22, that is, in the upper part of each of the four corners of the square opening, there is arranged an upward spray nozzle 27. With a DC high voltage applied to the discharge electrode, with a negative corona discharge generated between the discharge electrode and the dust collecting electrode 22, and with charged particulates collected on the dust collecting electrode 22, the upward spray nozzle 27 jets atomized washing water in a nearly perpendicular upward direction, thereby forming a wet wall on the surface of the dust collecting electrode 22.

Description

  The present invention relates to a wet electrostatic precipitator and a dust collecting method, and more particularly to a wet electrostatic precipitator and a dust collecting method capable of preventing fire occurrence more appropriately.

Conventionally, electrostatic precipitators have been used for the purpose of dust removal of large air volumes in production processes, and have made a great contribution to the prevention of air pollution and environmental measures.
In particular, the wet electrostatic precipitator creates a water film on the surface of the dust collecting electrode when the fine particles are very fine and the bulk density is low, or the specific resistance of the fine particles is too low or too high. It has a structure that flows down with this water. For this reason, wet electrostatic precipitators are widely used because they exhibit stable and high dust collection efficiency without causing re-scattering phenomenon and reverse ionization phenomenon.

The wet type electrostatic precipitator includes a smooth dust collecting electrode and a discharge electrode (see, for example, Patent Document 1).
When the dust collection electrode is grounded and a negative high voltage is applied to the discharge electrode, a vigorous corona discharge is generated from the discharge electrode, and the dust collection space is filled with negative ions and electrons.
When a gas containing fine particles such as mist and dust flows in this dust collection space (hereinafter referred to as “ion space”), the fine particles in the gas are negatively charged.
The charged fine particles move toward the dust collecting electrode by the Coulomb force while being accompanied by electrostatic aggregation action, and adhere to the dust collecting electrode.
The conventional wet electrostatic precipitator cleans and removes the fine particles adhering to the dust collecting electrode by ejecting a large amount of washing water downward from a downward spray nozzle that is spaced apart above the dust collecting electrode. .

Japanese Patent Application No. 2000-313963

  However, in the period for cleaning and removing fine particles (hereinafter referred to as “intermittent cleaning period”), the spark voltage may decrease when cleaning water having a large particle size passes around the discharge electrode.

For this reason, conventionally, in the intermittent cleaning period, the application of the DC high voltage V to the discharge electrode is stopped (the value of the DC voltage V is set to 0), or the value of the DC high voltage V is decreased. As a result, the dust collection efficiency was significantly reduced.
Therefore, conventionally, the intermittent cleaning period in which the dust collection efficiency is remarkably reduced has to be as short as possible and as long as possible. For example, an intermittent cleaning period of about 10 minutes has to be provided with an interval of 8 hours.
For this reason, conventionally, since the cleaning water is stopped for a long period between the intermittent cleaning periods (8 hours in the above example), a fire occurs when local overheating occurs with the surface of the dust collecting electrode being dried. There is a risk. In the following, factors that may cause a fire will be described in more detail.

  When the value of the DC high voltage V applied to the discharge electrode exceeds a certain value Vs, spark, that is, spark discharge occurs. A voltage value Vs at which such a spark is generated is hereinafter referred to as “spark generation voltage value Vs”. The spark generation voltage value Vs depends on the properties of the dust-containing gas (the gas containing fine particles to be collected) that circulate in the ion space. Since the nature of the dust-containing gas changes without being constant in the ion space, the spark generation voltage value Vs also changes.

Therefore, even if control for making the DC high voltage V constant is applied to the conventional wet electrostatic precipitator, the value of the DC high voltage V may exceed the spark generation voltage value Vs, and spark may occur. Further, when the discharge line is cut and comes into contact with the dust collecting electrode, a large current flows on the surface of the dust collecting electrode, so that local heating occurs.
When the dust collecting electrode in which such local heating is generated is dry, there is a risk of ignition and fire.

  In particular, in recent years, in wet electrostatic precipitators for discharging corrosive gases containing sulfur, chlorine, etc., fiber reinforced plastic (FRP) is used as a dust collecting electrode in contact with the corrosive gas and its surrounding members to prevent corrosion. : Fiber Reinforced Plastics) member may be employed. In such a case, the risk of fire is further increased.

  Needless to say, fire prevention measures have been taken for conventional wet electrostatic precipitators, but there is a need to implement measures that can prevent fires more appropriately than conventional measures. .

  This invention is made | formed in view of such a condition, and aims at preventing a fire outbreak more appropriately.

The wet electric dust collector of one aspect of the present invention is
A discharge electrode to which a DC high voltage is applied;
A dust collecting electrode for collecting fine particles;
A spray nozzle that ejects cleaning water for cleaning and removing fine particles collected on the dust collecting electrode to the dust collecting electrode,
The dust collecting electrode is composed of an assembly of a plurality of the units, with a cylinder having an opening having a predetermined shape as a unit.
The discharge electrode is accommodated in each of the plurality of units constituting the dust collection electrode,
The spray nozzle is disposed above at least one of the regions surrounded by the plurality of units constituting the dust collecting electrode, and the spray water is ejected by ejecting the cleaning water. Forming a wet wall on the surface of the dust collecting electrode,
It is characterized by that.

The dust collection method of the wet type electrostatic precipitator according to one aspect of the present invention,
With a cylinder having an opening of a predetermined shape as a unit, a dust collecting electrode constituted by an assembly of a plurality of the units,
A discharge electrode accommodated in each of the plurality of units constituting the dust collection electrode;
A spray nozzle disposed above at least one of the regions formed by the plurality of units constituting the dust collecting electrode;
A dust collecting method for a wet electric dust collector comprising:
In the state where a high DC voltage is applied to the discharge electrode, a negative corona discharge is generated in the vicinity of the discharge electrode, and charged fine particles are collected in the dust collection electrode.
The spray nozzle is configured to form a wet wall on the surface of the dust collecting electrode by spraying cleaning water for cleaning and removing fine particles collected on the dust collecting electrode to the dust collecting electrode.
It is characterized by that.

In the wet electric dust collector and the dust collecting method of one aspect of the present invention,
With a cylinder having an opening of a predetermined shape as a unit, a dust collecting electrode constituted by an assembly of a plurality of the units,
A discharge electrode accommodated in each of the plurality of units constituting the dust collection electrode;
A spray nozzle disposed above at least one of the regions formed by the plurality of units constituting the dust collecting electrode;
The following operation is performed by the wet type electrostatic precipitator provided with.
That is, a high DC voltage is applied to the discharge electrode, a negative corona discharge is generated in the vicinity of the discharge electrode, and charged fine particles are collected in the dust collection electrode.
Washing water for washing and removing fine particles collected on the dust collecting electrode is ejected to the dust collecting electrode by the spray nozzle, and as a result, a wet wall is formed on the surface of the dust collecting electrode.

  According to the present invention, it is possible to more appropriately prevent the occurrence of a fire.

It is sectional drawing which shows schematic structure of the wet electric dust collector which concerns on one Embodiment of this invention. It is a perspective view which shows schematic structure inside the housing of the wet electric dust collector of FIG. It is a top view which shows schematic structure inside the housing of the wet electric dust collector of FIG. It is the figure which showed typically the mode of the washing water ejected as a mist form from each of the upward spray nozzle of the wet electric dust collector of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a schematic configuration of a wet electrostatic precipitator 1 according to an embodiment of the present invention.
Specifically, FIG. 1 (A) and FIG. 1 (B) are cross-sectional views showing a schematic configuration of the external appearance of the wet electrostatic precipitator 1, and are cross-sectional views seen from different directions substantially perpendicular to each other.

The wet electric dust collector 1 is provided with an upper casing 11, a dust collecting electrode 22, a lower casing 13, and a frame 14.
The casing of the wet electrostatic precipitator 1 is configured by combining the upper casing 11, the dust collection electrode 22, and the lower casing 13 in this order from above. The casing of the wet electrostatic precipitator 1 is fixed by a frame 14 so as to be spaced apart from the ground by a predetermined distance. In this embodiment, conductive FRP is adopted as the material of the casing of the wet electrostatic precipitator 1.

FIG. 2 is a perspective view showing a schematic configuration inside the housing of the wet electrostatic precipitator 1.
FIG. 3 is a top view illustrating a schematic configuration inside the housing of the wet electrostatic precipitator 1.

  As shown in FIG. 2 and FIG. 3, an upper grid 21, a dust collecting electrode 22, a lower grid 23, an electrode rod 24, a discharge wire 25, a weight 26, An upward spray nozzle 27 and a cleaning pipe 28 are provided.

  As shown in FIG. 2, the upper grid 21, the dust collection electrode 22, and the lower grid 23 are spaced apart from each other by a predetermined distance in that order from above, and are substantially parallel to each other in the horizontal direction. It is arranged.

As shown in FIGS. 2 and 3, the dust collection electrode 22 is configured by repeatedly arranging a plurality of chambers with a rectangular tube as a unit (hereinafter, such units are referred to as “chambers”). The
Specifically, hereinafter, one of the substantially horizontal directions is referred to as “vertical direction”, and a direction perpendicular to the vertical direction is referred to as “lateral direction”. In this case, by repeatedly arranging N units in the vertical direction and repeating M units in the horizontal direction (hereinafter referred to as “N × M”), the dust collection electrode 22 is configured.
Here, N and M are independent arbitrary integer values, and in this embodiment, as shown in FIG. 1, the number of chambers of the dust collection electrode 22 is N × M = 9 × 9. .
In FIGS. 2 to 4, the number of chambers of the dust collection electrode 22 is N × M = 3 × 3 for the convenience of explanation only. In other words, in FIG. 2 to FIG. 4, only the center 3 × 3 chambers of the 9 × 9 chambers constituting the dust collection electrode 22 are shown for convenience of explanation.
Here, a dust collecting electrode configured as a collection of rectangular tubes, such as the dust collecting electrode 22, is generally called a “square tube collecting electrode” and has a dust collecting electrode area per unit volume. Since it is large, it has the feature that a compact design is possible.
In this embodiment, conductive FRP is adopted as the material of the dust collection electrode 22.

In this embodiment, the discharge electrode for the dust collection electrode 22 is constituted by an electrode rod 24 and a discharge wire 25.
As shown in FIG. 2, the electrode rod 24 is disposed so as to penetrate the center inside of a predetermined chamber of the dust collecting electrode 22 in a substantially vertical direction, the upper end portion is fixed to the upper grid 21, and the lower end portion is the lower portion. Fixed to the grid 23.
As shown in FIG. 2, the discharge line 25 is suspended from the upper grid 21 and is disposed so as to penetrate the center inside of a predetermined chamber of the dust collection electrode 22 in a substantially vertical direction. The discharge line 25 is also connected to a weight 26 provided on the upper part of the lower grid 23 so as to have a tension that does not loosen.
A negative DC high voltage V is directly applied to the electrode rod 24 from the DC high voltage generator 30. On the other hand, the negative DC high voltage V from the DC high voltage generator 30 is applied to the discharge line 25 via the electrode rod 24 and the upper grid 21.

The upward spray nozzle 27 is disposed above the four corners of each chamber of the dust collecting electrode 22 and ejects cleaning water flowing through the cleaning pipe 28 as a fine mist in a substantially vertical upward direction.
Here, “fog” refers to a state in which several to several hundred water droplets having a micron-order diameter are included in a 1 cm ³ space. In the present embodiment, the cleaning water is ejected from the upward spray nozzle 27 in a substantially vertical upward direction as water droplets having a diameter of about 200 to 800 microns.
Although details will be described later with reference to FIG. 4, the mist ejected from each of the upward spray nozzles 27 disposed above the four corners of each chamber of the dust collecting electrode 22 is the side surface of each chamber of the dust collecting electrode 22. It becomes a water film covering the whole. That is, a wet wall is formed on the side surface of each chamber of the dust collection electrode 22 by the cleaning water ejected as mist from the upward spray nozzle 27. As a result, the growth of fine particles such as mist and dust attached to the dust collecting electrode 22 can be prevented, and these fine particles can be cleaned and removed more reliably than before.

  In addition, as shown in FIG. 1, you may make it provide the downward spray nozzle 29 in the predetermined upper position spaced apart from the upper end part of the dust collecting electrode 22 only predetermined distance similarly to the conventional wet electric dust collector.

  Next, the operation of the above wet electrostatic precipitator 1 will be described.

With the dust collecting electrode 22 grounded, a negative DC high voltage V is applied from the DC high voltage generator 30 to the electrode rod 24 and the discharge wire 25. Hereinafter, for convenience of explanation, the electrode rod 24 and the discharge line 25 are collectively referred to as “discharge electrode”.
When the value of the DC high voltage V increases, a negative corona discharge occurs between the discharge electrode and each side surface of the dust collecting electrode 22 surrounding the discharge electrode. As a result, the discharge electrode 22 Negative ions move in the direction toward each side of the room, and ion wind is generated in the same direction.
Thus, in the wet electrostatic precipitator 1 of this embodiment, the internal space of each room of the dust collection electrode 22 becomes an ion space. Therefore, as shown in FIG. 1, a gas G1 containing fine particles such as mist and dust is supplied to the lower part of the casing of the wet electrostatic precipitator 1, and the opening at the upper end from the opening at the lower end of each room of the dust collecting electrode 22 is provided. When distributed toward the part, the fine particles are charged by the collision of negative ions.
The charged fine particles are moved by receiving a force from the discharge electrode in the direction toward each side of each room of the dust collecting electrode 22 by a direct current electric field inside each room of the dust collecting electrode 22, and the dust collecting electrode 22. Adhere to each side of each room.
In this way, fine particles are removed from the gas G1. The gas G2 obtained as a result of the removal of the fine particles from the gas G1 is released from the upper end of each chamber of the dust collecting electrode 22, and further, as shown in FIG. 1, the housing of the wet electrostatic precipitator 1 of the present embodiment. It is discharged from the top.
The operation of the wet electrostatic precipitator 1 of the present embodiment so far is basically the same as the operation of the conventional wet electrostatic precipitator.

  However, the subsequent operation, that is, the operation of cleaning and removing the fine particles adhering to the dust collecting electrode 22 is different between the wet electrostatic precipitator 1 of the present embodiment and the conventional wet electrostatic precipitator.

  That is, in the conventional wet electrostatic precipitator, a small number of downward spray nozzles are provided above the dust collecting electrode by a predetermined distance. Such a small number of downward spray nozzles spray and wash a large amount of cleaning water in a substantially vertical downward direction, thereby cleaning and removing fine particles adhering to the dust collecting electrode.

In contrast, in the wet electrostatic precipitator 1 of the present embodiment, the upward spray nozzles 27 are provided in the vicinity of the upper corners of each room of the dust collecting electrode 22.
FIG. 4 is a diagram schematically showing the state of the washing water ejected as mist from each of the upward spray nozzles 27.
As shown in FIG. 4, each of the upward spray nozzles 27 ejects the cleaning water flowing through the cleaning pipe 28 as a fine mist in a substantially vertical upward direction.
Each of a large number of mists (fine water droplets of about 200 to 800 microns) ejected from the upward spray nozzle 27 in a substantially vertical upward direction falls in a radial pattern with respect to all horizontal directions due to the influence of gravity. It becomes a water film which covers the side body of each chamber of the dust collection electrode 22. That is, a wet wall is formed on the side surface of each chamber of the dust collection electrode 22 by the cleaning water ejected as mist from the upward spray nozzle 27. As a result, the growth of fine particles such as mist and dust attached to the dust collecting electrode 22 can be prevented, and these fine particles can be cleaned and removed more reliably than before.

The wet electrostatic precipitator 1 according to the present embodiment capable of such an operation has the following characteristics as compared with the conventional wet electrostatic precipitator.
That is, as described above, in the conventional wet electrostatic precipitator, a small number of downward spray nozzles are simply provided at a position higher than the dust collecting electrode. Therefore, a large amount of washing water is required to surely remove the fine particles adhering to the dust collecting electrode.
On the other hand, in the wet electrostatic precipitator 1 according to the present embodiment, the cleaning water is ejected from the upward spray nozzle 27 in a substantially vertical upward direction as a fine mist. For this reason, since the dispersion | distribution of washing water becomes good, the amount of washing water used can be smaller than before.
Specifically, for example, when the dust collecting electrode area is 126 m ² , the conventional wet electric dust collector required a cleaning water amount of 150 L / min, but in the wet electric dust collector 1 of the present embodiment, 15 L The amount of cleaning water used is / min.
Here, the more the washing water passes around the discharge electrode, the more easily spark (spark discharge) is generated. Therefore, compared with the conventional wet electrostatic precipitator, the wet electrostatic precipitator 1 according to the present embodiment, which has an overwhelmingly small amount of washing water used, significantly suppresses the occurrence of sparks.
Furthermore, in the wet electrostatic precipitator 1 of the present embodiment, since the cleaning water is ejected as a fine mist, the particle size of the cleaning water when passing around the discharge electrode is compared with that of the conventional wet electrostatic precipitator. Therefore, the occurrence of sparks is further suppressed.

  Since the wet electrostatic precipitator 1 of this embodiment has such a feature, for example, as described in the following (1) to (4), there are advantageous effects as compared with the conventional wet electrostatic precipitator. Is possible.

  (1) In the wet electrostatic precipitator 1 of the present embodiment, even when the cleaning water is ejected from the upward spray nozzle 27, since the occurrence of spark is greatly suppressed, the intermittent cleaning period is continued for a long time. In some cases, it is possible to provide a continuous cleaning period. As a result, a wet wall is always formed on the side surface of each chamber of the dust collection electrode 22, and the dust collection electrode 22 is hardly dried. Thereby, even if abnormal discharge occurs, it becomes possible to more appropriately prevent the occurrence of fire.

  (2) In the wet electrostatic precipitator 1 of the present embodiment, since a fire can be prevented more appropriately as described above, a conductive material is used as a material of a member in contact with gas (hereinafter referred to as “gas contact part”). It becomes easy to adopt FRP. Thereby, corrosion of a gas contact part is prevented more reliably, As a result, the lifetime of the wet electric dust collector 1 of this embodiment becomes long. However, in this case, the electrical resistance value of the FRP used for other than the dust collection electrode 22 is desirably 500Ω or less.

(3) In the wet electrostatic precipitator 1 of the present embodiment, as described above, the cleaning period can be continued for a long time, and in some cases, a continuous cleaning period can be provided, which facilitates maintenance.
That is, the longer the cleaning period, the more reliably the fine particles adhering to the dust collecting electrode are cleaned and removed. Therefore, for example, it is possible to reduce the number of manual cleaning of the dust collecting electrode during periodic inspection.
In addition, for example, even when performing such cleaning, a conventional wet electrostatic precipitator accumulates a large amount of fine particles adhering to the dust collecting electrode and sticks to it. Work is required.
On the other hand, in the wet electrostatic precipitator 1 of this embodiment, since the wet wall is always formed on the surface of the dust collecting electrode 22, most of the fine particles adhering to the dust collecting electrode 22 are washed and removed before being deposited. Is done. As a result, in the wet type electrostatic precipitator 1 of this embodiment, the scraping work is not necessary, and a simple work using, for example, high-pressure washing water is sufficient.

(4) As described above in the section “Problems to be Solved by the Invention”, in the conventional wet electrostatic precipitator, during the intermittent cleaning period, the value of the DC voltage V needs to be reduced to 0 or decreased. The dust collection efficiency was significantly reduced.
On the other hand, in the wet electrostatic precipitator 1 of this embodiment, since the occurrence of spark is greatly suppressed even during the cleaning period in which the cleaning water is ejected from the upward spray nozzle 27, the DC high voltage applied to the discharge electrode. The value of V can be kept almost constant without decreasing. This makes it possible to maintain the dust collection efficiency at a certain level or more even during the cleaning period.

In other words, in order to achieve the effects (1) to (4) described above, a wet wall is almost always formed on the side surface of each chamber of the dust collecting electrode 22, and the spark frequency is constant. What is necessary is just to spout washing water so that it may keep below.
In order to enable such washing water to be ejected, the amount of washing water per unit area on the side surface of each chamber of the dust collecting electrode 22 may be appropriately managed.
That is, when the amount of cleaning water per unit area is below a certain level, it becomes impossible to form a wet wall almost always on the side surface of each chamber of the dust collection electrode 22. On the other hand, when the amount of washing water per unit area is more than a certain level, sparks frequently occur. As described above, in order to keep the frequency of sparking below a certain level while forming a wet wall almost always in each chamber of the dust collection electrode 22, the lower limit value and the upper limit value of the amount of cleaning water per unit area Exists.
Therefore, if the cleaning water is ejected within the range between the lower limit value and the upper limit value of the amount of cleaning water per unit area (hereinafter referred to as “appropriate range”), the side surface of each chamber of the dust collection electrode 22 In addition, it is possible to keep the frequency of occurrence of sparks below a certain level while forming a wet wall almost constantly, and as a result, the effects (1) to (4) described above can be achieved.
Specifically, for example, when dust is removed by washing, the appropriate range is from the lower limit value 0.10 including 0.15 L / m ² · min to the upper limit value 0.25 L / m ² · min. Further, for example, in the case of cleaning and removing mist is proper range in the range of the upper limit value 0.20L ^/ m 2 · min from the lower limit value 0.075 containing 0.10L ^/ m 2 · min.

Here, the change of the amount of cleaning water per unit area can be realized by changing the number of upward spray nozzles 27, for example. That is, in the above embodiment, the upward spray nozzle 27 is provided above all four corners of each chamber of the dust collection electrode 22, but if the cleaning water can be ejected within an appropriate range, the dust collection electrode 22 is not necessarily used. It is not necessary to provide them all above the four corners of each chamber.
Alternatively, if the cleaning water can be ejected within an appropriate range, it is not necessary to eject the cleaning water (fog) from all the upward spray nozzles 27, and only a predetermined number of upward spray nozzles 27 selected from the above. The washing water may be jetted from. That is, the ejection of cleaning water from one or more upward spray nozzles 27 may be stopped as appropriate.
Furthermore, in the above-described embodiment, the upward spray nozzle 27 that ejects cleaning water in a substantially vertical upward direction is provided. However, if the cleaning water can be ejected within an appropriate range, the ejection direction of the cleaning water (mist) Is not particularly limited to a substantially vertical upward direction, and may be in any direction.

  As described above, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

For example, as the dust collection electrode 22 of the above-described embodiment, a square tube type dust collection electrode having a square tube having a square shape as a chamber (unit) is employed, but is not limited thereto.
Specifically, for example, the shape of the opening of each chamber constituting the rectangular tube-type dust collecting electrode is not particularly required to be a square, and may be an N-gon (N is an integer value of 3 or more). In this case, the upward spray nozzle 27 and the like may be disposed around at least one of the N corners of each chamber.
Further, for example, a dust collecting electrode constituted by an assembly of a plurality of chambers may be employed, with a cylinder having a shape other than an N-gon shape such as a circular shape as a chamber. In this case, the upward spray nozzle 27 and the like may be disposed above at least one of the regions surrounded by the plurality of chambers.
Here, in the case of a rectangular tube-shaped dust collecting electrode having an N-shaped rectangular tube as a chamber, a region surrounded by a plurality of chambers is an intersection of a plurality of chambers, that is, each chamber. Each of the N corners.
Therefore, an arrangement method in which the upward spray nozzle 27 and the like are disposed above at least one of the regions formed by being surrounded by a plurality of chambers is a high-level concept. That is, an arrangement method in which the upward spray nozzle 27 and the like are disposed above at least one point among the intersections of a plurality of units, that is, above at least one corner among N corners of each unit is an opening method. This is a subordinate concept of the above superordinate concept, which is applied in the case of a rectangular tube-shaped dust collecting electrode in which the shape of the portion is an N-square square tube.

  DESCRIPTION OF SYMBOLS 1 Wet electrostatic precipitator, 21 Upper grid, 22 Dust collector electrode, 23 Lower grid, 24 Electrode rod, 25 Discharge line, 26 Weight, 27 Upward spray nozzle, 28 Cleaning pipe, 30 DC high pressure generator

Claims (6)

A discharge electrode to which a DC high voltage is applied;
A dust collecting electrode for collecting fine particles by negative corona discharge generated in the vicinity of the discharge electrode based on the DC high voltage;
A spray nozzle that ejects cleaning water for cleaning and removing fine particles collected on the dust collecting electrode to the dust collecting electrode;
With
The dust collecting electrode is composed of an assembly of a plurality of the units, with a cylinder having an opening having a predetermined shape as a unit.
The discharge electrode is accommodated in each of the plurality of units constituting the dust collection electrode,
The spray nozzle is disposed above at least one of the regions surrounded by the plurality of units constituting the dust collecting electrode, and the spray water is ejected by ejecting the cleaning water. Forming a wet wall on the surface of the dust collecting electrode,
Wet electric dust collector. The spray nozzle spouts the washing water in a water amount within a range in which the occurrence frequency of sparks can be kept below a certain level after forming a wet wall on the surface of the dust collecting electrode.
The electric dust collector according to claim 1. The spray nozzle ejects the washing water in a substantially vertical upward direction.
The wet electrostatic precipitator according to claim 1 or 2. The spray nozzle ejects the washing water as mist,
The wet electrostatic precipitator according to any one of claims 1 to 3. The plurality of units constituting the dust collection electrode are rectangular tubes having an N-shaped opening (N is an integer value of 3 or more),
The spray nozzle is disposed above at least one of the intersections of the plurality of units constituting the dust collection electrode.
The wet electrostatic precipitator according to any one of claims 1 to 4. With a cylinder having an opening of a predetermined shape as a unit, a dust collecting electrode constituted by an assembly of a plurality of the units,
A discharge electrode accommodated in each of the plurality of units constituting the dust collection electrode;
A spray nozzle disposed above at least one of the regions formed by the plurality of units constituting the dust collecting electrode;
In a dust collection method of a wet electric dust collector comprising:
In the state where a high DC voltage is applied to the discharge electrode, a negative corona discharge is generated in the vicinity of the discharge electrode, and charged fine particles are collected in the dust collection electrode.
The spray nozzle is configured to form a wet wall on the surface of the dust collecting electrode by spraying cleaning water for cleaning and removing fine particles collected on the dust collecting electrode to the dust collecting electrode.
Dust collection method.

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