JP2002177815A - Electric dust collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric dust collector capable of realizing a space- saving and a low cost by enhancing a capturing efficiency. SOLUTION: The electric dust collector is provided with a ceramics dust collection part 12 constituted so as to collect a dust in a gas flowing in through- holes at the inner wall surfaces of the through-holes by disposing the ceramics 15 having a large number of through-holes 16 between a first electrode 13 and a second electrode 14 and applying a high voltage to these electrodes to apply an electric field to a whole ceramics. The flat plate-like first and second electrodes are arranged as opposed to each other and a cross section shape of the through-hole of the ceramics is made to a rectangular shape in which a length is longer in a direction perpendicular to the electric field direction formed between the electrodes or may be made to a slit-like shape in which the length is longer in the direction perpendicular to the electric field direction and which has a length over a whole length of a ceramics width in the same perpendicular direction. This ceramics dust collection part may be disposed at a latter stage of a conventional dust collection part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic precipitator, which is useful when applied to, for example, the removal of fly ash contained in exhaust gas from a coal-fired boiler.

[0002]

2. Description of the Related Art A conventional electric dust collector (EP: electrosta
The tic precipitator) applies a high voltage between the discharge electrode and the dust collection electrode, generates corona discharge and ionizes the gas, and charges the dust in the gas flowing between the discharge electrode and the dust collection electrode. And the charged particles are collected by a dust collection electrode.

FIG. 5 is a view showing a configuration example of such a conventional electric dust collector, and FIG. 6 is a sectional view of a dust collecting portion provided in the electric dust collector as viewed from above. The conventional electrostatic precipitator 1 shown in FIG. 5 is of a dry type, and has a plurality of stages (three stages in the illustrated example) in series along the gas flow direction (direction of arrow A) in order to obtain a desired high dust collection performance. Is provided with a dust collecting section 2.

As shown in FIG. 6, the dust collecting section 2 has a dust collecting electrode 3 which is a flat electrode and a discharge electrode 4 which is a rod-shaped electrode. The discharge electrodes 4 extend in the up-down direction (the direction orthogonal to the paper surface of FIG. 6), and a large number of discharge electrodes 4 are arranged in a line at a predetermined interval along the gas flow direction. The dust collecting electrodes 3 are arranged to face each other along the gas flow direction so as to sandwich the row of discharge electrodes 4 from both sides. Spacing D ₁ of the dust collection electrode 3 and the discharge electrode 4 is, for example, 100mm or so. A high voltage is applied to the dust collecting electrode 3 and the discharge electrode 4 by a high voltage DC power supply 5. At this time, a voltage is applied so that the dust collection electrode 3 to which the earth 6 is applied becomes a positive electrode and the discharge electrode 4 becomes a negative electrode.

Therefore, according to the electric dust collecting apparatus 1 having the above structure, when a high voltage is applied to the dust collecting electrode 3 and the discharge electrode 4 of the dust collecting section 2 by the high voltage DC power supply 5, the gas around the discharge electrode is locally discharged. Corona discharge occurs due to electrical breakdown, and gas molecules are ionized by the corona discharge. As a result, electric charges are given to the dust (such as fly ash contained in the exhaust gas of a coal-fired boiler) in the gas flowing in the electric field (between the dust collecting electrode 3 and the discharge electrode 4) by the negative ions at this time. The charged particles move to the dust collecting electrode 3 by the Coulomb force and are collected.

[0006]

However, in the above-mentioned conventional electric precipitator, the distance between the precipitating electrode 3 and the discharging electrode 4 is 10 or more.
Since it is as long as about 0 mm, the moving distance of the charged particles from the discharge electrode 4 to the dust collecting electrode 3 is long, so that the length of the dust collecting part 2 in the gas flow direction needs to be long. In addition, the charged particles are transferred to the collection electrode 2
Since the dust collection area is small, it is necessary to increase the number of stages of the dust collection section 2 in order to obtain a desired high collection performance. For this reason, the entire apparatus becomes large, a large installation space is required, and the cost is high. In addition, the need for higher performance is also anticipated as a measure to tighten regulations on exit dust concentration in the future.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an electric precipitator capable of improving the collection efficiency, saving space and reducing costs in view of the above problems.

[0008]

Means for Solving the Problems A first method for solving the above problems is described below.
The electrostatic precipitator of the present invention arranges a porous dielectric having a large number of through holes penetrating along the gas flow direction between the first electrode and the second electrode, and connects the porous dielectric to the first electrode and the second electrode. By applying a high voltage to apply an electric field to the entire porous dielectric, dust (charged particles) in the gas flowing through the through-hole of the porous dielectric is collected on the inner wall surface of the through-hole. It is characterized by having a dielectric dust collecting part.

Further, the electric dust collector of the second invention is the electric dust collector of the first invention, wherein the first electrode is a cylindrical electrode surrounding the periphery of the porous dielectric, and the second electrode is a cylindrical electrode surrounding the porous electrode. It is a rod-shaped electrode arranged at the inner center along the gas flow direction.

[0010] The electric dust collector of the third invention is the electric dust collector of the first invention, wherein the first electrode and the second electrode are plate-like electrodes, and the porous dielectric material extends along the gas flow direction. And the through hole of the porous dielectric has a rectangular cross section that is long in a direction perpendicular to the direction of the electric field formed between the first electrode and the second electrode.

The electric dust collector according to a fourth aspect of the present invention is the electric dust collector according to the first aspect of the present invention, wherein the first electrode and the second electrode are plate-like electrodes, and the porous dielectric material extends along the gas flow direction. And the through-hole of the porous dielectric has a cross-sectional shape that is long in a direction orthogonal to the direction of the electric field formed between the first electrode and the second electrode and has a width of the porous dielectric in the orthogonal direction. It is characterized in that it has a slit shape having a length that is substantially the entire length.

Further, in the electric dust collecting apparatus according to the fifth invention, a high voltage is applied between the dust collecting electrode and the discharge electrode, and a charge is applied to the dust in the gas flowing between the dust collecting electrode and the discharge electrode. A dust collector configured to collect the charged particles on a dust collecting electrode is disposed at a front stage, and a dielectric collector according to claim 1, 2, 3, 3 or 4 is disposed at a rear stage of the dust collector. A dust part is arranged, and the charged particles coming out of the former dust collecting part are collected on the inner wall surface of the through hole of the porous dielectric in the latter dielectric dust collecting part. .

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the same parts as those in the related art (FIGS. 5 and 6) are denoted by the same reference numerals.

[First Embodiment] FIG. 1 is a configuration diagram of an electric precipitator according to a first embodiment of the present invention. 2A is a longitudinal sectional view of a ceramic dust collecting unit provided in the electric dust collecting apparatus (a cross-sectional view taken along line CC in FIG. 2B), and FIG. 3 is a cross-sectional view (a cross-sectional view taken along line BB of FIG. 2A).

<Structure> The electric precipitator 11 of the first embodiment shown in FIG. 1 is of a dry type, in which a precipitator 2 is disposed at a preceding stage (upstream in a gas flow direction indicated by an arrow A). It has a two-stage configuration in which the ceramic dust collecting unit 12 is arranged at the latter stage (downstream side in the same gas flow direction).

The dust collecting section 2 is similar to a conventional dust collecting section (see FIGS. 5 and 6). That is, the dust collecting section 2 includes a dust collecting electrode 3 which is a flat electrode and a discharge electrode 4 which is a rod-shaped electrode as shown in FIG. The discharge electrodes 4 extend in the up-down direction (the direction orthogonal to the paper surface of FIG. 6), and a large number of discharge electrodes 4 are arranged in a line at a predetermined interval along the gas flow direction. The dust collecting electrodes 3 are arranged to face each other along the gas flow direction so as to sandwich the row of discharge electrodes 4 from both sides. Distance D ₁ of the dust collection electrode 3 and the discharge electrode 4 is, for example, 100mm or so. A high voltage is applied to the dust collecting electrode 3 and the discharge electrode 4 by a high voltage DC power supply 5. At this time, a voltage is applied so that the dust collection electrode 3 to which the earth 6 is applied becomes a positive electrode and the discharge electrode 4 becomes a negative electrode.

Accordingly, when a high voltage is applied to the dust collecting electrode 3 and the discharge electrode 4 of the dust collecting section 2 by the high-voltage DC power supply 5, the gas around the discharge electrode is locally broken down and corona discharge occurs,
The gas molecules are ionized by the corona discharge. As a result, the negative ions at this time give an electric charge to the dust (such as fly ash in the exhaust gas of a coal-fired boiler) flowing in the electric field (between the dust collecting electrode 3 and the discharge electrode 4). The particles move to the dust collecting electrode 3 by the Coulomb force and are collected.

The charged particles that have not been collected by the former dust collector 2 exit the dust collector 2 and are introduced into the subsequent ceramic dust collector 12.

As shown in FIG. 2, the ceramic dust collector 1
2, the ceramics 15 as a dielectric material is
And the second electrode 14. The ceramics 15 have a large number of through holes 16 penetrating along the gas flow direction.
These through holes 16 serve as gas flow paths. Each of the through holes 16 has a square cross-sectional shape and is aligned in the vertical and horizontal directions in FIG.
The entire ceramic 15 is in a honeycomb shape. The length D ₂ of one side of the cross section of the through-hole 16 is made, for example, about 10mm.

The first electrode 13 is a cylindrical electrode having a rectangular cross section, and is arranged so as to surround the ceramic 15. The second electrode 14 is a rod-shaped electrode, and is disposed at a central portion inside the first electrode 13 along the gas flow direction. The first electrode 13 and the second electrode 14 are connected to a high-voltage DC power supply 17.
To apply a high voltage. At this time, a voltage is applied such that the first electrode 13 to which the ground 18 is applied becomes a positive electrode and the second electrode 14 becomes a negative electrode.

<Operation and Effect> According to the electric precipitator of the first embodiment, the first electrode 13 is
When a high voltage is applied to the first electrode 13 and the second electrode 14,
The electric field generated between the second electrode 14 and the ceramic 15
It is applied to the whole. Therefore, the charged particles which are charged in the first-stage dust collecting section 2 and introduced into the second-stage ceramic dust collecting section 12 are collected on the inner wall surface of the through hole 16 of the ceramics 15 by the action of the electric field applied to the entire ceramics 15. Is done.

Since the ceramics 15 have a large number of through holes 16, the ceramic dust collecting portion 12 has a significantly larger dust collecting area than the conventional dust collecting portion 2 (see FIGS. 5 and 6). Dust collection efficiency is greatly improved. For this reason, the number of stages of the dust collecting section can be reduced. For example, conventionally, a three-stage configuration as shown in FIG. 5 was required to obtain a desired high dust collection performance. In the first embodiment, a two-stage configuration as shown in FIG. 1 can be used. . Therefore, the whole apparatus becomes compact, and space saving and cost reduction can be achieved. In addition, even if the ceramics 15 are provided between the first electrode 13 and the second electrode 14, the pressure loss does not increase so much because the ceramics 15 has many through holes 16.

Further, since the charged particles flow through each through hole 16 of the ceramics 15 and are collected on the inner wall surface of each through hole 16, the moving distance of the charged particles is shorter than in the conventional case. For this reason, the length D _{3 of} the ceramic dust collecting portion 12 in the gas flow direction is set.
Can be shortened, and as a result, the entire apparatus can be made more compact and space can be saved.

Note that the charged particles are not collected on the entire inner wall surface of the through hole 16, but are collected on one inner wall surface in a direction orthogonal to the direction of the electric field. For example, in the through-hole 16A of FIG. 2B, it is collected on the inner wall surface 16A-1 on the upper side in the figure, in the through-hole 16B, it is collected on the inner wall surface 16B-1 on the right side in the figure, and in the through-hole 16C in the figure. It is collected on the lower inner wall surface 16C-1, and in the through hole 16D, the inner wall surface 16A-1 on the left side in the figure.
Collected at. Therefore, the second embodiment and the third embodiment described below have an enlarged inner wall surface on the side for collecting the charged particles.

[Embodiment 2] FIG. 3A is a longitudinal sectional view of a ceramic dust collecting portion provided in an electric dust collecting apparatus according to Embodiment 2 of the present invention (line EE in FIG. 3B). Arrow cross section),
FIG. 3B is a cross-sectional view of the ceramic dust collecting portion (FIG.
It is a DD line sectional view of (a). The overall configuration of the electric precipitator of the second embodiment is the same as that of the above-described first embodiment (see FIG. 1), and the subsequent ceramic precipitator is replaced with the ceramic precipitator 12 shown in FIG. 3 is replaced with the ceramic dust collecting portion 22 shown in FIG. 3, and therefore detailed description is omitted here.

<Structure> In the electric dust collector of the second embodiment, a dust collector 2 similar to the conventional one is arranged at the front stage (see FIG. 1), and a ceramic dust collector 22 shown in FIG. 3 is arranged at the rear stage. This is a two-stage configuration.

As shown in FIG. 3, the ceramic dust collector 2
2, the ceramics 25 as a dielectric is first electrode 23
And the second electrode 24. The ceramics 25 is a porous dielectric having a large number of through holes 26 penetrating along the gas flow direction (the direction of the arrow A), and these through holes 26 serve as gas flow paths.

Moreover, the cross-sectional shape of each of the through holes 26 is in a direction orthogonal to the direction of the electric field (the left-right direction in FIG. 3B) formed between the first electrode 23 and the second electrode 24. It has a long rectangular shape. That is, the inner wall surface in the direction orthogonal to the electric field direction (the inner wall surface on the side that collects charged particles) 26-1
Is wider than the inner wall surface 26-2 parallel to the direction of the electric field. Field direction length D ₄ of the cross section of the through-hole 26 is, for example, about 3mm. The through holes 26 are aligned in the up, down, left, and right directions in FIG. 3B, and the entire ceramics 25 has a honeycomb shape.

The first electrode 23 and the second electrode 24 are plate-shaped electrodes, and the ceramics 25 are arranged along the gas flow direction.
Are arranged opposite to each other. A high voltage is applied to the first electrode 23 and the second electrode 24 by a high-voltage DC power supply 27. At this time, a voltage is applied such that the first electrode 23 to which the earth 28 is applied becomes a positive electrode and the second electrode 24 becomes a negative electrode.

<Operation and Effect> According to the electrostatic precipitator of the second embodiment, the first electrode 23 is
When a high voltage is applied to the first electrode 23 and the second electrode 24,
The electric field generated between the second electrode 24 and the ceramic 25
It is applied to the whole. Therefore, the charged particles charged in the first-stage dust collecting section 2 and introduced into the second-stage ceramic dust collecting section 22 are subjected to the action of the electric field applied to the entire ceramics 25, so that the inner wall surface 26-1 of the through-hole 26 of the ceramics 25 is actuated.
Collected in.

Since the ceramics 25 has a large number of through holes 16, the ceramic dust collecting portion 22 has a significantly larger dust collecting area than the conventional dust collecting portion 2 (see FIGS. 5 and 6). Dust collection efficiency is greatly improved.

Moreover, the cross-sectional shape of the through hole 26 of the ceramics 25 is rectangular, which is long in a direction orthogonal to the direction of the electric field formed between the first electrode 23 and the second electrode 24, thereby achieving the above-described operation. Compared with the first embodiment, the dust collection area is further increased, the dust collection efficiency is improved, and the entire apparatus is made compact, so that space saving and cost reduction can be achieved. Note that, like the first embodiment, the first electrode 2
Even if ceramics 25 is provided between 3 and the second electrode 24,
Since the ceramics 25 have a large number of through holes 26, the pressure loss does not increase so much.

Further, since the through-hole 26 of the ceramics 25 has a rectangular cross-sectional shape that is long in the direction perpendicular to the electric field direction, the length in the electric field direction is shorter than that in the first embodiment, and the charging is performed. Since the moving distance of the particles is short, the dust collection efficiency is high. For this reason, the ceramic dust collecting section 22
The gas flow direction length D ₅ can be further shortened than the first embodiment, as a result, further apparatus overall space saving can be achieved becomes compact.

[Embodiment 3] FIG. 4A is a vertical sectional view of a ceramic dust collecting portion provided in an electric dust collecting apparatus according to Embodiment 3 of the present invention (GG line in FIG. 4B). Arrow cross section),
FIG. 4B is a cross-sectional view of the ceramic dust collecting portion (FIG.
It is an FF line sectional view of (a)). The overall configuration of the electric precipitator of the third embodiment is the same as that of the above-described first embodiment (see FIG. 1), and the subsequent ceramic precipitator is replaced with the ceramic precipitator 12 shown in FIG. 4 is replaced with the ceramic dust collecting portion 32 shown in FIG. 4, and a detailed description thereof will be omitted.

<Structure> In the electric precipitator of the third embodiment, a precipitator 2 similar to the conventional one is disposed (see FIG. 1), and a ceramic precipitator 32 shown in FIG. This is a two-stage configuration.

As shown in FIG. 4, the ceramic dust collector 3
2, the ceramics 35 as a dielectric material is
And the second electrode 34. The ceramics 35 is a porous dielectric having a large number of through holes 36 penetrating along the gas flow direction (the direction of arrow A), and these through holes 36 serve as a gas flow path.

Moreover, the cross-sectional shape of each of the through holes 36 is in a direction orthogonal to the direction of the electric field (the left-right direction in FIG. 4B) formed between the first electrode 33 and the second electrode 34. The slit has a long shape and extends over substantially the entire length of the ceramic width in the orthogonal direction (the vertical width of the ceramics 35 in FIG. 4B). In other words, the slit-shaped through-hole 36 has such a shape that a plurality of rectangular through-holes 26 in the vertical direction shown in FIG.

For this reason, the inner wall surface 36-1 in the direction orthogonal to the electric field direction (the inner wall surface on the side where charged particles are collected) 36-1 is much wider than the inner wall surface 36-2 parallel to the electric field direction. . The electric field direction length D ₆ of the cross section of the through hole 36 is, for example, 3
mm. The through holes 36 are aligned in the left-right direction in FIG. 4B, and the entire ceramics 35 has a honeycomb shape.

The first electrode 33 and the second electrode 34 are flat electrodes, and the ceramics 35 are arranged along the gas flow direction.
Are arranged opposite to each other. A high voltage is applied to the first electrode 33 and the second electrode 34 by a high-voltage DC power supply 37. At this time, a voltage is applied such that the first electrode 33 to which the ground 38 is applied becomes a positive electrode and the second electrode 34 becomes a negative electrode.

<Operation and Effect> According to the electrostatic precipitator of the third embodiment, the first electrode 33 is supplied by the high-voltage DC power supply 37.
When a high voltage is applied to the first electrode 33 and the second electrode 34,
The electric field generated between the second electrode 34 and the ceramic 35
It is applied to the whole. Accordingly, the charged particles charged in the first-stage dust collecting section 2 and introduced into the second-stage ceramic dust collecting section 32 are subjected to the action of the electric field applied to the entire ceramics 35, so that the inner wall surface 36-1 of the through hole 36 of the ceramics 35 is actuated.
Collected in.

Since the ceramics 35 has a large number of through holes 36, the ceramic dust collecting portion 32 has a significantly larger dust collecting area than the conventional dust collecting portion 2 (see FIGS. 5 and 6). Dust collection efficiency is greatly improved.

Further, the cross-sectional shape of the through hole 36 of the ceramics 35 is long in the direction orthogonal to the direction of the electric field formed between the first electrode 33 and the second electrode 34 and is substantially equal to the width of the ceramics in the orthogonal direction. By having a slit shape having a length extending over the entire length, the dust collection area is further increased and dust collection efficiency is improved as compared with the first and second embodiments,
The whole apparatus is compact, so that space saving and cost reduction can be achieved. Further, since the pressure loss is reduced as compared with the second embodiment, the device configuration has a lower pressure loss.

Further, since the through hole 36 of the ceramics 35 has a slit shape having a transverse cross section that is long in a direction orthogonal to the electric field direction, the length of the through hole 36 in the electric field direction is shorter than that of the first embodiment, and the charge is reduced. Because the moving distance of the particles becomes shorter,
Dust collection efficiency increases. Therefore, the ceramic dust collector 3
The second gas flow direction length D _7, can be further shortened than the first embodiment, as a result, further apparatus overall space saving can be achieved it becomes compact.

In the first, second and third embodiments, a high voltage is applied between the dust collecting portion 2 and the dust collecting electrode 3 and the discharge electrode 4 as shown in FIG. Dust collection electrode 3 and discharge electrode 4
A dust collector 2 configured to apply a charge to the dust in the gas flowing between the dust collector and the charged particles and collect the charged particles in a dust collecting electrode 3 is disposed at a front stage. Although the configuration is such that the dust collecting units 12, 22, or 32 are arranged, the present invention is not necessarily limited to this, and an electric dust collecting device including only the ceramic dust collecting units 12, 22, or 32 may be used. That is, the electric field formed between the first electrode 13, 23 or 33 and the second electrode 14, 24 or 34 also
Since electric charges can be given to the dust in the gas, the dust can be collected by an electric dust collector provided with only the ceramic dust collector 12, 22, or 32.

In other words, the ceramic dust collectors 12 and 2
If the dust charge at 2 or 32 is not sufficient,
It is effective to dispose the dust collecting unit 2 similar to the conventional one at the front stage and dispose the ceramic dust collecting unit 12, 22, or 32 at the subsequent stage as in the first, second, or third embodiment. is there.

In the first, second, and third embodiments, the ceramics 15, 25, or 35 is used as the dielectric.
The dielectric material is not limited to ceramics, and may be another dielectric material. For example, in the case of a dielectric shape as shown in FIG. 4, a cloth stretched up and down may be used.

Further, the cross-sectional shape of the through-hole in the porous dielectric is not necessarily limited to the shape shown in the first, second or third embodiment, but may be another shape.

[0048]

As described above, the electrostatic precipitator of the first invention has a porous dielectric having a large number of through holes penetrating along the gas flow direction. By disposing between the first electrode and the second electrode, and applying a high voltage to the first electrode and the second electrode to apply an electric field to the entire porous dielectric, the gas flowing through the through-hole of the porous dielectric can be used. And a dielectric dust collecting portion configured to collect the dust on the inner wall surface of the through hole.

Further, the electric dust collector of the second invention is the electric dust collector of the first invention, wherein the first electrode is a cylindrical electrode surrounding the periphery of the porous dielectric, and the second electrode is formed of the first electrode. It is a rod-shaped electrode arranged at the inner center along the gas flow direction.

That is, according to the electrostatic precipitator of the first or second aspect, when a high voltage is applied to the first and second electrodes, an electric field generated between the first and second electrodes is generated. Applied to the entire porous dielectric. Therefore, charged particles charged in the preceding stage of the present electrostatic precipitator and introduced into the present electrostatic precipitator or charged particles in the present electric precipitator, by the action of the electric field applied to the entire porous dielectric, It is collected on the inner wall surface of the through hole of the porous dielectric.

Since the porous dielectric has a large number of through-holes, the dielectric dust collecting part has a significantly larger dust collecting area than the conventional dust collecting part, and the dust collecting efficiency is greatly improved. For this reason, the number of stages of the dust collecting section can be reduced. Therefore, the whole apparatus becomes compact, and space saving and cost reduction can be achieved. Note that even if a porous dielectric is provided between the first electrode and the second electrode, the porous dielectric has a large number of through holes, and therefore does not increase the pressure loss so much.

Further, since the charged particles flow through each through-hole of the porous dielectric and are collected on the inner wall surface of each through-hole, the moving distance of the charged particles is shorter than before. For this reason, the length of the porous dielectric in the gas flow direction can also be shortened, and as a result, the entire apparatus can be made more compact and space can be saved.

Further, the electric dust collector of the third invention is the electric dust collector of the first invention, wherein the first electrode and the second electrode are plate-like electrodes, and the porous dielectric material is arranged along the gas flow direction. And the through hole of the porous dielectric has a rectangular cross section that is long in a direction perpendicular to the direction of the electric field formed between the first electrode and the second electrode.

Therefore, according to the electric dust collector of the third invention, the same operation and effect as those of the electric dust collector of the first or second invention can be obtained. In addition, the cross-sectional shape of the through-hole of the porous dielectric is rectangular, which is long in a direction orthogonal to the direction of the electric field formed between the first electrode and the second electrode. Dust collection efficiency has improved,
The whole apparatus is compact, so that space saving and cost reduction can be achieved.

Further, the through hole of the porous dielectric has a rectangular cross-section that is long in the direction perpendicular to the direction of the electric field. Therefore, the length of the through-hole in the electric field is short, and the moving distance of the charged particles is short. , Dust collection efficiency is increased. For this reason, the length of the dielectric dust collecting portion in the gas flow direction can be further reduced, and as a result, the entire apparatus can be further compacted to save space.

Further, the electric dust collector according to the fourth invention is the electric dust collector according to the first invention, wherein the first electrode and the second electrode are plate-shaped electrodes, and the porous dielectric material extends along the gas flow direction. And the through-hole of the porous dielectric has a cross-sectional shape that is long in a direction orthogonal to the direction of the electric field formed between the first electrode and the second electrode and has a width of the porous dielectric in the orthogonal direction. It is characterized in that it has a slit shape having a length that is substantially the entire length.

Therefore, according to the electric dust collector of the fourth invention, the same operation and effect as those of the electric dust collector of the first, second or third invention can be obtained. In addition, the cross-sectional shape of the through-hole of the porous dielectric is long in a direction orthogonal to the direction of the electric field formed between the first electrode and the second electrode, and extends over substantially the entire length of the ceramic width in the orthogonal direction. By making the slit shape of the above, further than the electric dust collector of the third invention,
The dust collecting area is increased, the dust collecting efficiency is improved, and the entire apparatus is made compact, so that space saving and cost reduction can be achieved. Further, since the pressure loss is reduced as compared with the electric dust collector of the third aspect of the present invention, the device configuration has a lower pressure loss.

Further, in the electric dust collecting apparatus according to the fifth invention, a high voltage is applied between the dust collecting electrode and the discharge electrode, and a charge is applied to the dust in the gas flowing between the dust collecting electrode and the discharge electrode. A dust collector configured to collect the charged particles on a dust collecting electrode is disposed at a front stage, and a dielectric collector according to claim 1, 2, 3, 3 or 4 is disposed at a rear stage of the dust collector. A dust part is arranged, and the charged particles coming out of the former dust collecting part are collected on the inner wall surface of the through hole of the porous dielectric in the latter dielectric dust collecting part. .

Therefore, according to the electric dust collecting apparatus of the fifth invention, the same operation and effect as those of the electric dust collecting apparatus of the first, second, third or fourth invention can be obtained. This is particularly effective when the dust in the dielectric dust collecting portion is not sufficiently charged.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electric precipitator according to Embodiment 1 of the present invention.

2A is a longitudinal sectional view of a ceramic dust collecting unit provided in the electric dust collecting apparatus, and FIG. 2B is a transverse sectional view of the ceramic dust collecting unit.

FIG. 3A is a longitudinal sectional view of a ceramic dust collecting unit provided in an electric dust collecting apparatus according to Embodiment 2 of the present invention, and FIG. 3B is a transverse sectional view of the ceramic dust collecting unit.

FIG. 4A is a longitudinal sectional view of a ceramic dust collecting unit provided in an electric dust collecting apparatus according to Embodiment 3 of the present invention, and FIG. 4B is a transverse sectional view of the ceramic dust collecting unit.

FIG. 5 is a configuration diagram of a conventional electric precipitator.

FIG. 6 is a cross-sectional view of a dust collecting portion provided in the electric dust collecting device as viewed from above.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Electric dust-collecting device 2 Dust-collecting part 3 Dust-collecting electrode 4 Discharge electrode 5 High-voltage DC power supply 6 Earth 11 Electric dust-collecting device 12 Ceramic dust-collecting part 13 1st electrode 14 2nd electrode 15 Ceramics 16, 16A, 16B, 16C, 16D through-hole 16A-1, 16B-1, 16C-1, 16D-1 inner wall surface 17 high-voltage DC power supply 18 earth 22 ceramic dust collecting part 23 first electrode 24 second electrode 25 ceramics 26 through-hole 26-2, 26 2 inner wall surface 27 high-voltage DC power supply 28 earth 32 ceramic dust collecting part 33 first electrode 34 second electrode 35 ceramics 36 through hole 36-1, 26-2 inner wall surface 37 high-voltage DC power supply 38 earth

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B03C 3/41 B03C 3/41 C 3/47 3/47 3/49 3/49 3/62 3/62 3/14 C // F23J 15/00 F23J 15/00 Z (72) Inventor Katsuhisa Kojima 2-1-1 Shinhama, Arai-machi, Takasago-shi, Hyogo Pref. Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratories (72) Inventor Katsumasa Masui Hyogo 1-1-1 Wadazaki-cho, Hyogo-ku, Kobe, Japan F-term in Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (reference) 3K070 DA07 DA30 4D054 AA02 BA01 BA02 BA06 BA07 BA08 BB02 BB05 BC02 BC06 BC13 BC14

Claims (5)

[Claims] A porous dielectric having a large number of through holes penetrating along a gas flow direction is disposed between a first electrode and a second electrode, and a high voltage is applied to the first and second electrodes. A dielectric dust collecting portion is provided which is configured to collect dust and soot in gas flowing through the through hole of the porous dielectric by applying an electric field to the entire porous dielectric by applying the electric field to the inner wall surface of the through hole. An electrostatic precipitator. 2. The electrostatic precipitator according to claim 1, wherein the first electrode of the dielectric precipitator is a cylindrical electrode surrounding the perimeter of the porous dielectric, and the second electrode is a central electrode inside the first electrode. An electrostatic precipitator characterized in that it is a rod-shaped electrode arranged in a portion along a gas flow direction. 3. The electrostatic precipitator according to claim 1, wherein the first electrode and the second electrode of the dielectric precipitator are plate-like electrodes, and both sides of the porous dielectric are arranged along the gas flow direction. The through hole of the porous dielectric has a rectangular cross section that is long in a direction perpendicular to the direction of an electric field formed between the first electrode and the second electrode. apparatus. 4. The electrostatic precipitator according to claim 1, wherein the first electrode and the second electrode of the dielectric precipitator are plate-like electrodes, and both sides of the porous dielectric are arranged along the gas flow direction. And the through-hole of the porous dielectric has a cross-sectional shape that is longer in a direction orthogonal to the direction of the electric field formed between the first electrode and the second electrode, and is approximately the entire length of the width of the porous dielectric in the orthogonal direction. An electrostatic precipitator characterized in that it has a slit shape having a length extending over the entire length. 5. A high voltage is applied between the dust collecting electrode and the discharge electrode to give a charge to the dust in the gas flowing between the dust collecting electrode and the discharge electrode, and the charged particles are collected. A dust collector configured to collect the dust is disposed at a front stage, and a dielectric dust collector according to claim 1, 2, 3, or 4 is disposed at a stage subsequent to the dust collector, and a dust collector disposed at a front stage is disposed. An electrostatic precipitator, wherein charged particles emerging from a dust portion are collected on an inner wall surface of a through-hole of a porous dielectric in a subsequent dielectric precipitator.