JP3046805B2 - Electric dust collector - Google Patents

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 particulate matter to be collected by electric action.

[0002]

2. Description of the Related Art In an electrostatic precipitator, a gas containing fine particles such as dust flows in a flow path formed by a housing, and a charging section and a collector are sequentially passed through the flow path of the gas from an upstream side in a gas flow direction. A dust part is provided. The charging section is provided with a plate-shaped discharge electrode and a counter electrode extending in the direction of gas flow in order to increase the strength as compared with the discharge line, and a direct current power supply is provided between the discharge electrode and the counter electrode. DC voltage is applied. The discharge electrode is formed with a plurality of saw-tooth-shaped protrusions arranged in a direction perpendicular to the gas flow direction, and each protrusion protrudes toward the upstream side in the gas flow direction. In the charging section, corona discharge is generated from the tip of the projection of the discharge electrode toward the counter electrode, and the particulate matter in the gas passing between the electrodes is charged. The dust collecting part is provided with a first electrode and a second electrode, and the first and second electrodes are provided.
A DC voltage is applied between the electrodes by a DC power supply. In this dust collecting unit, an electric field is formed between the first electrode and the second electrode, and the particulate matter charged by the charging unit receives a force from the electric field and is collected on the first or second electrode. .
Such an electrostatic precipitator is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-28.
897 and JP-A-3-232554.

As another prior art, each projection formed on a discharge electrode is inclined with respect to the direction of gas flow,
That is, there is known a technique in which the discharge electrodes are alternately formed on both sides in the thickness direction.

In an electric precipitator using a discharge wire as a discharge electrode, the discharge electrode has a higher potential than the counter electrode when a voltage is applied so that the counter electrode has a higher potential than the discharge electrode. It is known that the discharge current for the same voltage is larger than when a voltage is applied as described above. Are also applied with a high potential.

[0005]

In order to improve the operation efficiency of the electrostatic precipitator, it is necessary to obtain a high discharge current, and an electric precipitator capable of obtaining this high discharge current is desired. ing.

Accordingly, it is an object of the present invention to provide an electric precipitator capable of obtaining a high discharge current.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a gas flow direction of a base provided in a flow path through which a gas containing particulate matter to be collected flows and extending along a direction intersecting the gas flow direction. A discharge electrode formed with a plurality of protrusions projecting in a tapered shape along the gas flow direction from an end of the discharge electrode; and a gas flow path, with a gap on both sides in a direction perpendicular to the gas flow direction from the discharge electrode. A corona discharge power supply that generates a corona discharge between each of the opposed electrodes disposed apart and each of the protrusions of the discharge electrode and the counter electrode, and applies a voltage so that the discharge electrode has a higher potential than the counter electrode. Wherein each of the protrusions has a protrusion protruding closer to one of the opposing electrodes on both sides of the discharge electrode, and the discharge electrodes are compared at the same potential difference between the discharge electrode and the counter electrode. And the counter electrode is higher than the discharge electrode. When the discharge electrode and a higher potential than the counter electrode in comparison with the case where the potential is an electric precipitator, characterized in that the large resulting discharge current between the counter electrode.

According to the present invention, a discharge electrode and a counter electrode are provided in a flow path through which a gas flows, and between these electrodes,
A voltage for generating corona discharge is provided by a corona discharge power supply. As a result, the gas passes between the electrodes, whereby the fine particles in the gas are charged, and the charged fine particles are collected by electrostatic force. As described above, the discharge electrode which generates corona discharge between the counter electrode and the counter electrode to charge the fine particles has a plurality of protrusions which are tapered from the base, and each protrusion protrudes closer to the counter electrode. Further, as the discharge electrode, a discharge electrode having a protrusion is used, and a voltage is applied so that the discharge electrode has a higher potential than the counter electrode, and a voltage is applied so that the counter electrode has a higher potential than the discharge electrode. In contrast, a large discharge current can be obtained between the electrode and the counter electrode, as compared with the same potential difference. Therefore, the operation efficiency of the electric dust collector can be improved.

According to the present invention, there is provided a gas flow path in which a gas containing particulate matter to be collected flows, and a base extending in a direction intersecting the gas flow direction and having a gas flowing from an end in the gas flow direction. A discharge electrode in which a plurality of protrusions projecting in a tapered shape along the flow direction are formed, and a counter electrode arranged in the gas flow path at intervals in a direction perpendicular to the gas flow direction from the discharge electrode. A corona discharge power supply that generates a corona discharge between each protrusion of the discharge electrode and the counter electrode, and applies a voltage so that the discharge electrode has a higher potential than the counter electrode; and a tip of each protrusion. The distance between the counter electrode and the direction perpendicular to the virtual plane including the base is 5 mm or more and 30 mm or more.
Hereinafter, the corona discharge power supply is an electric precipitator in which a voltage is applied so that a potential difference between a discharge electrode and a counter electrode is 5 kV or more and 25 kV or less.

According to the present invention, a discharge electrode and a counter electrode are provided in a flow path through which a gas flows.
A voltage for generating corona discharge is provided by a corona discharge power supply. As a result, the gas passes between the electrodes, whereby the fine particles in the gas are charged, and the charged fine particles are collected by electrostatic force. As described above, the discharge electrode that generates corona discharge between the counter electrode and the counter electrode in order to charge the fine particles has a plurality of protrusions that are tapered from the base. The corona discharge power supply applies a voltage so that the discharge electrode has a higher potential than the counter electrode. By using a discharge electrode having a projection and applying a voltage so that the discharge electrode has a higher potential than the counter electrode, compared to a case where a voltage is applied so that the counter electrode has a higher potential than the discharge electrode, A large discharge current can be obtained for the same voltage. Therefore, the operation efficiency of the electric dust collector can be improved. The distance between the tip of each protrusion and the counter electrode is 5 mm or more and 30 mm or less, and the potential difference between the discharge electrode and the counter electrode is 5 kV or more and 25 kV or less. The distance between the tip of each projection and the counter electrode is 5 m
When the distance is less than m, the density of the electrodes in the gas flow path increases, and the resistance to the flow of the gas increases. When the distance exceeds 30 mm, corona discharge hardly occurs and the operation efficiency decreases. . Therefore, by setting the distance between the tip of each projection and the counter electrode in the above range, the resistance to the gas flow can be reduced, and corona discharge can be easily generated, so that the operation efficiency can be increased.
In the case where the distance between the tip of each projection and the counter electrode is as described above, when the potential difference between the discharge electrode and the counter electrode is less than 5 kV, the discharge current is lower than when the counter electrode has a higher potential than the discharge electrode. When the potential of the discharge electrode is higher than that of the counter electrode, the discharge current is significantly lower. When the potential difference exceeds 25 kV, a spark discharge easily occurs. Therefore, when the distance between the tip of each projection and the counter electrode is within the above range, by setting the potential difference between the discharge electrode and the counter electrode within the range, it is possible to obtain a high discharge current with respect to the selected discharge voltage. And the occurrence of spark discharge can be prevented.

Further, in the power supply for corona discharge according to the present invention, the potential difference between the discharge electrode and the counter electrode is 10 kV to 20 kV.
It is characterized in that a voltage is applied so as to be as follows.

According to the present invention, the potential difference between the discharge electrode and the counter electrode is 10 kV or more and 20 kV or less. By further limiting the range of the potential difference in this manner, the discharge current when the discharge electrode has a higher potential than the counter electrode is less likely to be lower than the discharge current when the counter electrode has a higher potential than the discharge electrode. And the occurrence of spark discharge can be reliably prevented.

Further, according to the present invention, the distance between the tip of each of the projections and the counter electrode in the direction perpendicular to the virtual plane including the base is 20 mm, and the power supply for corona discharge is provided between the discharge electrode and the counter electrode. It is characterized in that a voltage is applied so that a potential difference becomes 14 kV or more and 20 kV or less.

According to the present invention, the distance between the tip of each projection and the opposing electrode is 20 mm, and the potential difference between the discharge electrode and the opposing electrode is 14 kV or more and 20 kV or less. In the case where the distance between the tip of each protrusion and the counter electrode is as described above, when the potential difference between the discharge electrode and the counter electrode is less than 14 kV, the discharge current is lower than when the counter electrode has a higher potential than the discharge electrode. When the potential of the discharge electrode is higher than that of the counter electrode, the discharge current may be lower. When the potential difference exceeds 20 kV, spark discharge may occur. On the other hand, if the distance between the tip of each projection and the counter electrode is set to the above-mentioned value, the potential difference between the discharge electrode and the counter electrode is set to the above-mentioned range, thereby ensuring a high discharge current with respect to the selected discharge voltage. Can be obtained, and generation of spark discharge can be reliably prevented.

Further, according to the present invention, the distance between the tip of each of the projections and the counter electrode in the direction perpendicular to the virtual plane including the base is set to 9 mm or more and 15 mm or less. Potential difference between 8 kV and more 2
It is characterized in that a voltage is applied so as to be 0 kV or less.

According to the present invention, the distance between the tip of each projection and the opposing electrode is 9 mm or more and 15 mm or less, and the potential difference between the discharge electrode and the opposing electrode is 8 kV or more and 20 kV or less. In the case where the distance between the tip of each protrusion and the counter electrode is as described above, when the potential difference between the discharge electrode and the counter electrode is less than 8 kV, the discharge current is lower than when the counter electrode has a higher potential than the discharge electrode. When the potential of the discharge electrode is higher than that of the counter electrode, the discharge current may be lower. When the potential difference exceeds 20 kV, spark discharge may occur. On the other hand, by setting the distance between the tip of each projection and the counter electrode to the above value and setting the potential difference between the discharge electrode and the counter electrode to the above range, it is possible to reliably obtain a high discharge current with respect to the selected discharge voltage. And the occurrence of spark discharge can be reliably prevented.

Further, the present invention is characterized in that each of the projections has a substantially triangular shape projected on a virtual plane including the base, and the triangles have mutually different lengths of two sides projecting from the base. I do.

According to the present invention, each projection has a substantially triangular shape projected on an imaginary plane including the base, and the triangles have mutually different lengths of two sides projecting from the base. That is, each projection projects obliquely from the base to the end of the base. Thereby, each projection has a sharper tip, without increasing the height of the projection from the base or shortening the length of the side connected to the base, as compared to isosceles triangle projections as in the prior art. The angle of the tip can be reduced. Therefore, the tip can be sharpened to improve the discharge efficiency, the charge rate of the fine particles can be improved and the dust collection efficiency can be improved, and the mechanical strength of each projection can be reduced and the tip can be prevented from being dissolved and oxidized. be able to. As described above, in the related art, the conflicting problems can be solved at the same time.

Each projection may be formed along the imaginary plane including the base, or may be formed so as to be more distant from the imaginary plane toward the tip.

Further, the present invention is characterized in that the shape of each of the projections projected on the virtual plane is a substantially right triangle, and sides connected to the base are sides other than the oblique sides.

According to the present invention, the shape of each projection projected onto the virtual plane is substantially a right triangle, and the side connected to the base is a side other than the oblique side. The angle of the tip of the projection can be reduced,
And the surface of the projection corresponding to the side protruding from the base faces the direction away from the base or is parallel to the direction away from the base, and each projection can be easily formed.

Further, the present invention is characterized in that the shape of each projection projected onto the virtual plane is a substantially obtuse triangle, and the side connected to the base is a side other than the opposite side of the obtuse angle.

According to the present invention, the shape of each of the projections projected on the virtual plane is substantially an obtuse triangle, and the sides connected to the base are sides other than the pair of obtuse angles. The angle of the tip of each projection can be made smaller than in the case of

[0024]

FIG. 1 is an enlarged plan view showing a part of a discharge electrode 1 for a dust collector according to an embodiment of the present invention. A plurality of projections 3 projecting from one end of a base 2 are formed on a discharge electrode 1 (hereinafter sometimes simply referred to as a “discharge electrode”) for a dust collector, and each projection 3 includes the base 2. The shape projected on a virtual plane parallel to the paper surface of No. 1 is a substantially triangular shape as indicated by a virtual line. The triangle 4 has two sides 5 and 6 projecting from the base 2 having different lengths. More specifically, the shape of each projection 3 projected on the virtual plane is a substantially obtuse triangle, and the sides 7 connected to the base 2 are sides 7 other than the obtuse opposite side 5 forming the angle θ1.

FIG. 2 is a simplified cross-sectional view showing an electric precipitator 10 using the discharge electrode 1. FIG. 1 shows section I of FIG. 2 as viewed from above. The electrostatic precipitator 10 is a device for collecting fine solid and liquid particulate matter to be collected, such as dust, carbon particles and water droplets, contained in a gas such as air and purifying the gas. Yes, it is used to purify air in tunnels, purify indoor air in ordinary houses, and purify various industrial exhaust gases. The electric dust collecting device 10 includes a charging unit 12 and a dust collecting unit 13.
A dust collector having a housing 15, a discharge electrode 1, a counter electrode 17, a first dust collector electrode 18, a second dust collector electrode 19, and a power supply for corona discharge. 20 and a power supply 21 for forming an electric field.

The housing 15 has an inflow opening 27 at one end.
Are formed at the other end, and a substantially horizontal flow path 29 communicating with the openings 27, 28 is formed. The gas containing the particulate matter to be collected is supplied by gas supply means (not shown) realized by, for example, a blower or the like.
From the housing 15, flows through the flow path 29 in the housing 15 from the inflow opening 27 to the outflow opening 28 as shown by the arrow B, and from the outflow opening 28 as shown by the arrow B2. It flows out of the housing 15. The electrostatic precipitator 10 is provided with a charging section 12 and a precipitating section 13 in order from the upstream side in the gas flow direction B along the gas flow path 29 formed by the housing 15.

A plurality of, in this embodiment, three, discharge electrodes 1 are provided in the flow path 29 of the charging section 12 through which the gas flows, and the flow direction of the gas (hereinafter sometimes simply referred to as the “flow direction”) B Are arranged at intervals in the direction perpendicular to the vertical direction, in this embodiment, the vertical direction which is the vertical direction in FIG.
Each discharge electrode 1 has the base 2 and the protrusion 3 as described above. The base 2 has a flat plate shape along the flow direction B,
The virtual plane 22 including the base is provided horizontally and in parallel with each other so as to be perpendicular to the vertical direction, and in a direction intersecting the flow direction B, in this embodiment, the flow direction B perpendicular to the paper surface of FIG. Extends vertically. Each protrusion 3 is formed so as to protrude from both ends in the width direction, which are respective ends on the upstream side and the downstream side in the flow direction B of the base 2. Each such discharge electrode 1 is made of, for example, stainless steel.

A plurality of, in this embodiment, four, counter electrodes 17 are provided in the flow path 29 of the charging section 12 through which the gas flows, and are mutually spaced from the discharge electrode 1 in the vertical direction perpendicular to the flow direction B. Are arranged in parallel. More specifically, each counter electrode 17 is a flat plate larger than each discharge electrode, and is disposed horizontally along the flow direction B in parallel with each discharge electrode 1. Are arranged so as to be positioned one by one.
At this time, a virtual plane 22 including the base 2 of each discharge electrode 1, that is, a virtual plane including a center position of the base 2 in the thickness direction,
The discharge electrodes 1 are arranged such that the distances D1 to the virtual plane 23 including the opposing electrodes 17 adjacent to both sides in the thickness direction, that is, the virtual plane including the center position of the counter electrodes 17 in the thickness direction are all equal. Each counter electrode 17 is made of, for example, stainless steel.

The first dust collecting portion electrode 18 has a flat plate shape, and a plurality of, in this embodiment, five, are provided in the flow passage 29 of the dust collecting portion 13, and are spaced apart in the vertical direction perpendicular to the flow direction B. It is arranged horizontally open. Each first dust collecting portion electrode 18
It has a flat plate shape and is arranged horizontally along the flow direction B and parallel to each other. The second dust collecting portion electrodes 19 are plate-shaped, and a plurality of, in this embodiment, four, are provided in the flow passage 29 in the dust collecting portion 13 and are arranged at intervals in a vertical direction perpendicular to the flow direction B. Have been. Each first dust collecting portion electrode 18
It has a flat plate shape and is arranged horizontally along the flow direction B and parallel to each other. More specifically, each second dust collecting portion electrode 19 has substantially the same size as each first dust collecting portion electrode 18 and is parallel to each first dust collecting portion electrode 19 horizontally along the flow direction B. And each discharge electrode 1 is connected to each counter electrode 17.
They are arranged so that they are located one by one between them. At this time, the virtual plane 2 including each first dust collecting portion electrode 18
4, a virtual plane including the center position of the first dust collecting portion electrode 18 in the thickness direction, and a virtual plane 25 including each second dust collecting portion electrode 19 adjacent on both sides in the thickness direction of the first dust collecting portion electrode 18;
That is, the second dust collecting portion electrodes 19 are arranged such that the distances D2 to the virtual plane including the center position in the thickness direction are all equal. These first and second dust collecting portion electrodes 18, 1
9 is made of, for example, stainless steel.

The corona discharge power supply 20 is a power supply for applying a voltage for generating corona discharge between each projection 3 of each discharge electrode 1 and the counter electrode 17, and a DC power supply is used. Each of the discharge electrodes 1 is controlled by a corona discharge power source 20.
A potential higher than the ground potential is applied.
Grounded. As a result, a voltage is applied between the discharge electrode 1 and the counter electrode 17 so that the discharge electrode 1 has a higher potential than the counter electrode 17, and a corona discharge occurs between each projection 3 of the discharge electrode 1 and the counter electrode. Is generated.

The electric field forming power supply 21 is a power supply for applying a voltage for forming an electric field between the first and second dust collecting portion electrodes 18 and 19, and a DC power supply is used. Each first dust collecting portion electrode 18 is given a potential lower than the ground potential by the electric field forming power supply 21, and the second dust collecting portion electrode 19 is grounded. As a result, a DC electric field having a higher potential is formed between the first and second electrodes 18 and 19 from the second dust collecting portion electrode 19 toward the first dust collecting portion electrode 18.

FIG. 3 is a sectional view taken along the line III--III of FIG. 1, FIG. 4 is a perspective view seen from the upper left side of FIG. 1, and FIG. 5 is a view seen from the lower left side of FIG. It is the perspective view seen. With reference to FIGS. 1 and 2, the projections 3 of each discharge electrode 1 are formed at equal intervals in the direction in which the base 2 extends (the vertical direction in FIG. 1), and go from the base 2 to the tip 31. As the distance from the virtual plane 22 including the base 2 increases. More specifically, each protrusion 3 is formed on the base 2.
And an angle θ2 about an axis parallel to the direction in which the base extends with respect to the virtual plane 22, for example, 10 °.
Virtual planes 32 and 33 inclined in the range of not less than 45 degrees and not more than 45 degrees
Is formed so as to protrude along. More specifically, the projections 3 are arranged such that the projections 3 adjacent to each other are opposite to each other with respect to the virtual plane 22 along virtual planes 32 and 33 in which θ2 is inclined about 30 degrees with respect to the virtual plane 22. It is formed so as to face the side. Each of the projections 3 can be formed by cutting a flat plate material and then bending the projections 3.

As described above, each of the projections 3 has a substantially obtuse triangular shape projected on the virtual plane 33, and has side surfaces 35, 36 on both sides in the thickness direction substantially along one of the virtual planes 32, 33; The obtuse triangle has a first end face 37 along the longest side that is the opposite side 5 of the obtuse angle forming the angle θ1 and a second end face 38 having an obtuse vertex at one end point. The second end face 38 forms an angle θ3 with respect to a direction perpendicular to the direction in which the base 2 on which the projections 3 are arranged extends (the left-right direction in FIG. 1).
The first end face 37 forms an angle θ4 with respect to the second end face 38 in a direction further inclined from a direction perpendicular to the direction in which the base 2 extends.

The angle θ1 is in the range of, for example, more than 90 degrees and 120 degrees or less so that each degree θ1 does not become too large in order to facilitate the formation of each projection 3. That is, the angle θ3 is in a range of more than 0 degrees and 30 degrees or less. In the present embodiment, the angle θ3 is 10 degrees, that is, the angle θ1 is 100 degrees. Also, the tip 4 of each projection 3
The angle θ4 which is an angle of 0 is, for example, in a range of 25 degrees or more and 45 degrees or less in order to sharpen the distal end portion 40. In the present embodiment, it is 40 degrees.

The first end face 37 of each projection 3 and the second end face 38 of the adjacent projection are in the direction from the tip 31 of each projection 3 toward the base 2, that is, a curved surface that is convex rightward in FIG. The third end surface 42 forming an arcuate surface is continuous. As a result, it is possible to prevent stress from being concentrated when bending each projection 3 as described above,
Damage can also be prevented. In addition, the width of the base end of each projection 3 connected to the base 2, that is, the dimension in the direction in which the projections 3 are arranged can be increased, and the distal end 40 can be sharpened.

Further, each projection 3 has a shape in which the thickness perpendicular to the imaginary planes 32 and 33 including each projection 3 decreases slightly toward the tip 31 or a shape in which the thickness does not change, that is, the first and second end faces. 37, 38 are formed so as to form a rectangular shape or a substantially rectangular shape. In the present embodiment, the shape is slightly reduced, that is, the first and second end faces 37, 3
8 is formed to have a substantially rectangular shape. This makes it possible to sharpen the tip 31 of each projection 3 and prevent it from becoming too thin like a needle. Each of the projections 3 has a triangle formed on the imaginary plane 22 by the base 2.
As if they were translated in the direction in which they extend.

The thickness W3 of the base 2 of the discharge electrode 1 is
In the present embodiment, it is 0.64 mm or more and 0.34 mm or less and 0.64 mm or less. An occupied width (referred to as a set width) W2 of each of the protrusions 3 protruding on both sides of the virtual plane 22 is set to 0.46 mm or more and 2 mm or less, that is, each protrusion 3 has a tip 31 perpendicular to the virtual plane from the base 2. The protrusion width W1 protruding in any direction is 0.08 mm or more.
It is 75 mm or less. In the present embodiment, the occupied width W2 is 1.5 mm, that is, the protrusion width W1 is 0.43 mm. The width W4 at the tip 31 of each projection 3 has a value slightly smaller than the thickness of the base as described above.

The width L1 of the base 2, that is, the width in the direction perpendicular to the direction in which the base 2 extends is 1.0 mm or more and 60 mm or less.
2, and the width L2 of the discharge electrode 1 in the flow direction B is 5 m.
m or more and 65 mm or less. In the present embodiment, the width L1 of the base 2 is set to 10 mm, and the protrusion height H of each protrusion 3 is set to 2.
0 mm, that is, the width L2 of the discharge electrode 1 is 14 mm
It is.

Each of the projections 3 is one in the direction in which the base 2 extends.
4 or more and 18 or less per inch, that is, a pitch of 4
１８18 / inch. In this embodiment, ten pieces are formed per inch. Moreover, the tip 31 of each projection 2
The distance D3 between the electrode and the counter electrode 17 in the direction perpendicular to the virtual plane 22 is 5 mm or more and 30 mm or less. In the present embodiment, it is 20 mm.

In the present embodiment, each of the above dimensions is set as follows. Thickness W3 of base 2: 0.64 mm Width L1 of base 2: 10 mm Occupied width (set width) W2 of each projection 3: 1.5 mm Projection width W1 of each projection 3: 0.43 mm Projection height H of each projection 3 : 2 mm Pitch of each projection 3: 10 pieces / inch Width L2 of discharge electrode 1: 14 mm Distance D3 between tip 31 and counter electrode 17: 20 mm

The voltage applied between the discharge electrode 1 and the counter electrode 17 by the corona discharge power supply 20 is, for example, 5 kV or more and 25 kV or less. This voltage is preferably 10 kV or more and 20 kV or less. In particular, in the present embodiment where the distance D3 is 20 mm, 14 kV or more and 20 k
V or less. In addition, the electric field forming power supply 21
The voltage applied to the second dust collecting portion electrodes 18 and 19 is, for example, 5.5 kV.

FIG. 6 is a side view showing a part of the electric precipitator 10 as viewed from the left side of FIG. In such an electrostatic precipitator 10, a discharge electrode 1 and a counter electrode 17 are provided in a flow path 29 through which gas flows, and between these electrodes 1 and 17,
A voltage is applied by a corona discharge power supply 20. When such a voltage is applied, in the electric field formed between the electrodes, the lines of electric force are concentrated on the tip of each projection 3, and in the discharge region S <b> 1 as shown by the imaginary line, the tip of each projection 3 Corona discharge is generated between 3 and the counter electrode 17.
That is, each projection 3 projects so as to approach one of the opposing electrodes 17 adjacent to both sides in the thickness direction of the discharge electrode 1, and discharges between the opposing electrodes 17 on the adjacent side. As a result, when the gas passes through the charging section 12, the fine particles in the gas are charged by passing between the electrodes 1 and 17. Moreover, since each projection 3 is provided on both sides in the width direction of the base 2, two discharge regions S1 in the flow direction B are provided.
Can be formed, and the particulate matter can be reliably charged.

Further, when the gas containing the fine particles charged in the charging section 12 passes through the dust collecting section 13, the charged fine particles are applied to the first and second dust collecting section electrodes 18 and 19 by the electrostatic force, that is, the Coulomb force. It is sucked and collected.
In particular, a voltage is applied between the first and second dust collecting portion electrodes 18 and 19, and the charged fine particles are formed when passing between the first and second dust collecting portion electrodes 18 and 19. The fine particles charged with the large Coulomb force by the applied electric field are surely collected by the first and second dust collecting portion electrodes 18 and 19.

By using a so-called saw-toothed electrode having the base 2 and the respective projections 3 as described above, the durability of the discharge electrode 1 can be reduced as compared with the case where a discharge wire is used as the discharge electrode. And the discharge efficiency can be improved. More specifically, in the electrostatic precipitator 10, the voltage between the discharge electrode 1 and the counter electrode 17 is a high voltage immediately before the discharge generated between the electrodes 1 and 17 shifts from corona discharge to spark discharge. Occasionally, since it is known that a high performance is exhibited, the operation is performed at such a high voltage, but the mode shifts to the spark discharge due to the humidity of the gas, the density of the fine particles, the contamination of the discharge electrode 1 and the like. There are cases.

When such a spark discharge occurs, the electrode is dissolved and oxidized and deteriorated by heat generated in a larger amount than the corona discharge due to the spark discharge. For example, φ
When a discharge wire of 0.26 mm or φ0.5 mm is used, the discharge wire may be broken. Further, the discharge electrode generates a corona discharge, which causes a vibration caused by the discharge. Since such vibration reduces the discharge efficiency, it is conceivable to apply a tension to the discharge electrode in order to suppress the vibration, but if a large tension is applied, the discharge wire will break. If the tension is suppressed, vibration is not sufficiently suppressed,
Discharge efficiency is reduced. On the other hand, by using the sawtooth-shaped discharge electrode 1 as in the present invention, a large tension can be applied to the discharge electrode 1, vibration can be suppressed, and discharge efficiency can be improved.

FIG. 7 is a graph showing the discharge efficiency of the discharge electrode 1 and the discharge line. The horizontal axis indicates the power supply voltage, that is, the voltage between the electrodes, and the vertical axis indicates the discharge current. The first line 45 indicates the relationship between the inter-electrode voltage of the discharge electrode 1 and the discharge current, and the second line 46 indicates the relationship between the discharge electrode 1 and the
2 shows the relationship between the voltage between the electrodes and the discharge current when a discharge line is used instead of. When the power supply voltage is in the range of 0 kV to about 5 kV and in the range of about 13 kV to about 15 kV, there is no large difference in the discharge efficiency of the discharge electrode 1 and the discharge wire. However, in the range of about 5 kV to about 13 kV, The discharge efficiency of the electrode 1 greatly exceeds the discharge efficiency of the discharge line. That is, the discharge current when the discharge electrode 1 is used has a large ratio to the discharge current when the discharge wire is used. Thus, the discharge electrode 1 having each projection 3
Has excellent discharge characteristics with higher discharge efficiency than discharge wires.

Further, each of the projections 3 has a substantially triangular shape projected on an imaginary plane 22 including the base 2, and the triangles have mutually different lengths of two sides 5 and 6 protruding from the base 2. That is, each projection 3 projects obliquely from the base 2 to the end of the base 2. Thereby, each projection 3
As compared with a conventional isosceles triangular protrusion as in the prior art, the protrusion height H from the base 2 is larger or the side 7 connected to the base 2 is larger.
, And the tip 31 can be sharp, that is, the angle θ4 of the tip 31 can be reduced. Therefore, the tip 31 is sharpened, the electric force lines are concentrated, the discharge efficiency is improved, the charge rate of the fine particles is also improved, and the dust collection efficiency can be improved. Dissolution and oxidative degradation of the portion 40 can be prevented.

Further, in this embodiment, the shape of each projection 3 projected on the virtual plane 22 is a substantially obtuse triangle, and the side 7 connected to the base 2 is a side other than the obtuse angled pair 5, so that The angle of the tip 31 of each projection 3 can be smaller than in the case of the acute triangle and the right triangle.

Further, each projection 3 has a tip 31 as described above.
Are formed so as to move away from the imaginary plane 22 as the distance from the front surface 31 increases.
, The lines of electric force are easily concentrated on the tips 31 of the projections 3, corona discharge is easily generated between each projection 3 and the counter electrode 17, and the discharge efficiency is improved.

When the protrusion width W1 is less than 0.08 mm, the effect of improving the discharge efficiency by the concentration of the lines of electric force is small, and when the protrusion width W1 exceeds 0.75 mm, the resistance to the gas flow is reduced. growing. On the other hand, by setting the protrusion width W1 to 0.08 mm or more and 0.75 mm or less, the discharge efficiency can be improved and
It is possible to prevent the resistance against the gas flow from increasing, and to improve the operation efficiency of the entire apparatus. Further, when the protrusion height H is less than 0.5 mm, the degree of concentration of the lines of electric force at the distal end portion 40 is small, the discharge efficiency is reduced, the dust collection efficiency is reduced, and when the protrusion height H exceeds 2 mm, mechanical In this case, the mechanical strength is reduced, and the tip is easily dissolved and oxidized. On the other hand, the protrusion height H is 0.5
By setting the thickness to not less than 2 mm and not more than 2 mm, the discharge efficiency can be improved and the mechanical strength of each projection 3 can be increased, and the tip 40 can be prevented from melting and oxidizing.

Further, the base 2 is a flat plate along the gas flow direction B, and has a width L1 of 1 mm or more and 60 mm or less. When the width L1 is less than 1 mm, the strength of the discharge electrode 1 decreases, and when it exceeds 60 mm, the dimension in the gas flow direction increases. Therefore, by making the base 2 flat and setting the width L1 to the above range, resistance to gas flow can be reduced and high mechanical strength can be obtained. Further, even when the protrusions 3 are formed on both sides in the width direction of the base 2, the influence of the lines of electric force concentrated on the protrusions 3 formed on both sides in the width direction can be reduced, and high discharge efficiency can be obtained. Further, the base 2 has a thickness W2
Is 0.30 mm or more and 0.64 mm or less. When the width W2 is less than 0.30 mm, the strength of the discharge electrode 1 decreases, and when the width W2 exceeds 0.64 mm, the resistance to the gas flow increases. Therefore, the base 2 has a flat plate shape,
By setting the width W2 within the above range, resistance to the flow of gas can be reduced, high strength can be obtained, and the device can be prevented from being enlarged. By obtaining such high mechanical strength, it is possible to apply a large tension to the discharge electrode 1 as described above, thereby suppressing vibration and generating a stable discharge and improving discharge efficiency.

Further, each projection 3 is formed in a number of 4 to 18 per inch. If the number of the protrusions 3 per inch is less than 6, the distance between the protrusions 3 becomes too large, and the particles 3 pass between the discharge electrode 1 and the counter electrode 17 without being charged. If the substance is present and the number of protrusions 3 per inch exceeds 18, each protrusion 3
The lines of electric force concentrated on the front end portion 40 interfere with each other, and the discharge efficiency is reduced. Therefore, by setting the number of the projections 3 per inch to the above range, the particulate matter in the gas can be reliably charged, and the lines of electric force concentrated at the tip 40 of each projection 3 are mutually separated. Interference can be prevented and discharge efficiency can be increased. Further, in the present invention, the distance D3 between the tip 31 of each projection 3 and the counter electrode 17 is 5 mm or more and 30 mm or less. When the interval D3 is less than 5 mm, the gas flow path 29
, The resistance to the gas flow increases, and if the distance D3 exceeds 30 mm, corona discharge is less likely to occur, and the dust collection efficiency decreases. Therefore, by setting the interval D3 within the above range, the resistance to the gas flow can be reduced, and corona discharge can be easily generated, so that the dust collection efficiency can be increased.

Further, the distance D between the tip 31 and the counter electrode 17
3 is 20 mm, the thickness W3 of the base 2 is 0.64
mm, the width L1 of the base 2 is 10 mm, the occupied width (set width) W2 of each projection 3 is 1.5 mm, the projection width W1 of each projection 3 is 0.43 mm, and the projection height H of each projection 3 is
Is set to 2 mm, the pitch of each projection 3 is set to 10 / inch, and the width L2 of the discharge electrode 1 is set to 14 mm, thereby achieving each of the above-described effects and further achieving higher discharge efficiency.

FIG. 8 shows the case where the potential of the discharge electrode 1 is higher than that of the counter electrode 17 (hereinafter, sometimes referred to as “plus discharge”), and the case where the potential of the counter electrode 17 is higher than the discharge electrode 1 ( Hereinafter, it is a graph showing the discharge efficiency when “discharge is sometimes referred to as“ minus discharge ”.
That is, the voltage between the electrodes is shown, and the vertical axis shows the discharge current. The first line 51 shows the relationship between the inter-electrode voltage and the discharge current in the positive discharge when the discharge electrode 1 is used.
Numeral 2 indicates the relationship between the inter-electrode voltage and the discharge current in the negative discharge when the discharge electrode 1 is used. The third line 53 shows the relationship between the inter-electrode voltage and the discharge current in the positive discharge when a discharge wire of φ0.25 mm is used in place of the discharge electrode 1 in the above-described electric precipitator 10, and the fourth line 54 shows In the above-mentioned electrostatic precipitator 10, the relationship between the inter-electrode voltage and the discharge current in the negative discharge when a discharge wire of φ0.25 mm is used instead of the discharge electrode 1 is shown. The fifth line 55 shows the relationship between the inter-electrode voltage and the discharge current in the positive discharge in the case where a discharge wire of φ0.5 mm is used in place of the discharge electrode 1 in the above-mentioned electric precipitator 10, and the sixth line 56 shows The relationship between the inter-electrode voltage and the discharge current in the negative discharge when a discharge wire of φ0.5 mm is used in place of the discharge electrode 1 in the above-described electric precipitator 10 is shown.

The third line 53 and the fourth line 54, and the fifth line
As shown by the line 55 and the sixth line 56, when a discharge line is used, the voltage between the electrodes is 10 kV to 20 kV.
In the following range, it is shown that the negative discharge has higher discharge efficiency than the positive discharge, that is, the discharge current is higher for the same inter-electrode voltage. This is well known as described in the background section. On the other hand, as shown in the first line 51 and the second line 52,
When the discharge electrode 1 having each of the protrusions 3 projecting in a tapered shape is used, when the voltage between the electrodes is 14 kV or more and 20 kV or less, the discharge efficiency of the positive discharge is superior to that of the negative discharge. Although not shown in FIG. 8 for ease of illustration, when the discharge electrode 1 having the projections 3 is used, even when the voltage between the electrodes is more than 19 kV and 25 kV or less, the discharge current is positive. It has been confirmed that the value of discharge is higher than that of negative discharge. When the voltage between the electrodes is in the range of 13 kV to 14 kV, the discharge efficiency is reversed between the positive discharge and the negative discharge. However, even when the power supply voltage is in the range of 10 kV to 13 kV, the discharge efficiency in the positive discharge is lower than the discharge efficiency in the negative discharge. Although not significantly lower and not shown, even when the voltage between the electrodes is 5 kV or more and less than 10 kV,
It has been confirmed that similar discharge characteristics are exhibited.

As described above, a so-called saw-tooth electrode having a plurality of projections 3 projecting from the base 2 in a tapered shape is used as the discharge electrode so that the discharge electrode 1 has a higher potential than the counter electrode 17. By performing the positive discharge by applying a voltage, superior discharge efficiency can be obtained as compared with the case of the negative discharge by applying a voltage so that the counter electrode has a higher potential than the discharge electrode. That is, substantially the same or large discharge current can be obtained for the same voltage. Therefore, the particulate matter is easily charged, and the dust collection efficiency and the operation efficiency of the electric dust collection device 10 can be improved.

When the distance D3 between the tip 31 of each projection 3 and the counter electrode 17 is 5 mm or more and 30 mm or less, and the potential difference between the discharge electrode 1 and the counter electrode 17 is 5 kV or more and 25 kV or less, It has been confirmed that a positive discharge shows a better discharge efficiency than a negative discharge.
When the interval D3 is within the above range, the discharge electrode 1
When the potential difference between the counter electrode 17 and the counter electrode 17 is less than 8 kV, the discharge current at the time of plus discharge is much lower than the discharge current at the time of minus discharge, and the potential difference is 25 kV.
If it exceeds, spark discharge is likely to occur. Therefore, when the distance D3 between the tip 31 of each projection 3 and the counter electrode 17 is in the above range, by setting the potential difference between the discharge electrode 1 and the counter electrode 17 to the above range, the plus discharge is superior to the minus discharge. It shows a discharge efficiency, can obtain a high discharge current with respect to a set discharge voltage, and can prevent occurrence of spark discharge which causes deterioration of the discharge electrode 1.

When the distance D3 is set in the above range, the potential difference between the discharge electrode 1 and the counter electrode 17 becomes 1
The voltage is preferably 0 kV or more and 20 kV or less. When the inter-electrode voltage is in such a range, the discharge current at the time of negative discharge is less likely to be lower than the discharge current at the time of positive discharge, and the occurrence of spark discharge is reliably prevented. In particular, when the distance D3 is 20 mm, it is preferable that the potential difference between the discharge electrode 1 and the counter electrode 17 be 14 kV or more and 20 kV or less. When the potential difference between the discharge electrode 1 and the counter electrode 17 is less than 14 kV, the discharge current at the time of minus discharge may be lower than the discharge current at the time of plus discharge, and when the potential difference exceeds 20 kV,
Spark discharge may occur. On the other hand, when the distance D3 is 20 mm, the discharge electrode 1 and the counter electrode 1
7, the positive discharge can reliably obtain a higher discharge current than the negative discharge, and the generation of the spark discharge can be reliably ensured, as is clear from the graph shown in FIG. Can be prevented.

As described above, by improving the discharge efficiency and the dust collection efficiency, conventionally, the gas is reduced to 2-3 m / s.
Gas at 9 to 11 m / s
Processing can be carried out at a flow rate as high as possible, and rapid processing can be performed.

FIG. 9 is a sectional view showing a part of a discharge electrode 1A according to another embodiment of the present invention, and FIG.
It is a side view which shows a part of electric dust collecting apparatus 10A using. FIG. 9 is a diagram corresponding to FIG. 3, and FIG. 10 is a diagram corresponding to FIG. This embodiment has a configuration similar to that of the embodiment described with reference to FIGS. 1 to 8. Corresponding portions are denoted by the same reference numerals, and only different configurations will be described. I do. Each protrusion 3 of the discharge electrode 1 protrudes alternately on both sides of the virtual plane 22. Each protrusion 3 of the discharge electrode 1A has a protrusion protruding along the virtual plane 22 and a virtual plane along the virtual plane 33. The protrusion protruding to one side of the base 22 and the protrusion protruding to the other side of the virtual plane 22 along the virtual plane 32 are repeated in this order toward one of the extending directions of the base 2 (to the right in FIG. 10). Formed side by side.

In such a discharge electrode 1A, in the discharge region S1 as shown by the imaginary line, the tip 40 of each projection 3
A corona discharge is generated between the electrode and the counter electrode 17. That is, each projection 3 projecting along the virtual plane 22 has a tip 3
1 is a counter electrode 1 adjacent to both sides of the discharge electrode 1 in the thickness direction.
7 are equidistant from each other, so that the opposing electrodes 17 on both sides are
Discharge between and. Further, each projection 3 projecting so as to approach one of the opposing electrodes 17 adjacent on both sides in the thickness direction of the discharge electrode 1 discharges between the opposing electrodes 17 on the adjacent side. In the present embodiment, the protrusion width W1 and the occupation width W
Reference numeral 2 denotes a projection 3 formed so as to be away from the virtual plane 22. Such a discharge electrode 1
A can achieve the same effect as the discharge electrode 1 of the above-described embodiment.

FIG. 11 is a sectional view showing a part of a discharge electrode 1B according to another embodiment of the present invention, and FIG.
It is a side view which shows a part of electric dust collector 10B using B. FIG. 11 is a diagram corresponding to FIG. 3, and FIG. 12 is a diagram corresponding to FIG. This embodiment has a configuration similar to that of the embodiment described with reference to FIGS. 1 to 8. Corresponding portions are denoted by the same reference numerals, and only different configurations will be described. I do. Each protrusion 3 of the discharge electrode 1A includes a protrusion protruding along the virtual plane 22, a protrusion protruding on one side of the virtual plane 22 along the virtual plane 33, and a other side of the virtual plane 22 along the virtual plane 32. A projection protruding from
The virtual plane 6 is inclined with respect to the virtual plane 22 at an angle θ2B around an axis parallel to the direction in which the base extends.
It has projections respectively protruding on both sides of the virtual plane 22 along 0,61. Each of the protrusions 3 is one of the extending directions of the base 2 (the right side in FIG. 12), the virtual plane 22, the virtual plane 60, the virtual plane 32, the virtual plane 60, the virtual plane 22, and the virtual plane 6.
1, the virtual plane 33 and the virtual plane 61 are repeatedly projected in this order. Angle θ2B is, for example, half of angle θ2.

In such a discharge electrode 1 B, in the discharge region S 1 as shown by the phantom line, the tip 40
A corona discharge is generated between the electrode and the counter electrode 17. That is, each projection 3 projecting along the virtual plane 22 has a tip 3
1 is a counter electrode 1 adjacent to both sides of the discharge electrode 1 in the thickness direction.
7 are equidistant from each other, so that the opposing electrodes 17 on both sides are
Discharge between and. Further, each projection 3 projecting so as to approach one of the opposing electrodes 17 adjacent on both sides in the thickness direction of the discharge electrode 1 discharges between the opposing electrodes 17 on the adjacent side. In the present embodiment, the protrusion width W1 and the occupation width W
Reference numeral 2 designates the projection 3 formed so as to be farthest from the virtual plane 22. Such a discharge electrode 1B can achieve the same effect as the discharge electrode 1 of the above-described embodiment.

FIG. 13 is a side view showing a part of an electric precipitator using a discharge electrode 1C according to another embodiment of the present invention, and corresponds to FIG. In this embodiment, FIGS.
It has a configuration similar to that of the embodiment described with reference to FIG. 8, and corresponding portions are denoted by the same reference numerals, and only different configurations will be described. The discharge electrode 1 is formed along each of the virtual planes 32 and 33 so as to move away from the virtual plane 22 toward the tip 31.
All the projections 3 of C protrude along the virtual plane 22.
In such a discharge electrode 1C, in the discharge region S1 shown by the phantom line, the distal end portion 40 of each projection 3 and the counter electrode 1
7, a corona discharge is generated. That is, each projection 3
Since the tip 31 is equidistant from each of the opposing electrodes 17 adjacent on both sides in the thickness direction of the discharge electrode 1, discharge occurs between the opposing electrodes 17 on both sides.

The discharge electrode 1C has the same effect as the discharge electrode 1 of the above-described embodiment, except for the effect that each projection 3 projects away from the imaginary plane 22 as it approaches the tip 31. Can be achieved.

FIG. 14 is a graph showing the discharge efficiency of the discharge electrode 1 and the discharge electrode 1C. The horizontal axis indicates the power supply voltage, that is, the voltage between the electrodes, and the vertical axis indicates the discharge current. First line 6
Reference numeral 5 indicates the relationship between the discharge current and the inter-electrode voltage of the discharge electrode 1, and the second line 66 indicates the relationship between the discharge current and the inter-electrode voltage of the discharge electrode 1C. Power supply voltage from 0kV to about 16k
In the range up to V, there is no large difference in the discharge efficiency between the discharge electrode 1 and the discharge electrode 1C, but from about 16 kV to about 19 kV.
In the range up to kV, the discharge efficiency of the discharge electrode 1 greatly exceeds the discharge efficiency of the discharge electrode 1C. That is, by forming each of the protrusions 3 so as to move away from the virtual plane 22 toward the front end 31, the lines of electric force concentrated on the front end portion 40 of each of the adjacent protrusions 3 do not affect each other,
The discharge efficiency is improved as compared with the case where each projection 3 is formed along the virtual plane 22. Moreover, in the discharge electrode 1C,
When the voltage between the electrodes is 20 kV, spark discharge occurs,
Although a suitable corona discharge does not occur, each protrusion 3 is
, A suitable corona discharge is generated without shifting to spark discharge even if the voltage between the electrodes is 20 kV. Accordingly, the discharge electrode 1 can be used with a higher inter-electrode voltage than the discharge electrode 1C, and the operation efficiency of the electric precipitator 10 can be improved.

FIG. 15 is a side view showing a part of an electric precipitator 10D having a discharge electrode 1D according to another embodiment of the present invention, and corresponds to a part of the charging section 12 of FIG. This embodiment has a configuration similar to that of the embodiment described with reference to FIGS. 1 to 8. Corresponding portions are denoted by the same reference numerals, and only different configurations will be described. I do.

Each projection 3 of the discharge electrode 1 is formed on both sides in the width direction of the base 2, and each projection 3 of the discharge electrode 1 D is formed only at the upstream end of the base 2 in the flow direction. As described above, even when each projection 3 is formed only at one end of the base 2, the effect of making the shape of each projection 3 triangular as described above and the effect of positive discharge are achieved. Can be.

In the present embodiment, each dimension is set as follows, for example. Thickness W3 of base 2: 0.64 mm Width L1 of base 2: 11.5 mm Occupied width (set width) W2 of each projection 3: 1.24 mm Projection width W1 of each projection 3: 0.3 mm Projection height of each projection 3 Height H: 1.5 mm Pitch of each projection 3: 10 / inch Width L2 of discharge electrode 1: 13 mm Distance D3 between tip 31 and counter electrode 17: 15 mm

FIG. 16 shows a discharge electrode 1 as shown in FIG.
9 is a graph showing discharge efficiency in positive discharge and negative discharge when D is used. The horizontal axis indicates the power supply voltage, that is, the voltage between the electrodes, and the vertical axis indicates the discharge current. First line 7
0 indicates the relationship of the discharge current to the inter-electrode voltage in the positive discharge, and the second line 71 indicates the relationship of the discharge current to the inter-electrode voltage in the negative discharge. As shown in the first line 70 and the second line 71, when the dimensions are as described above, when the voltage between the electrodes is 11 kV or more and 12 kV or less, the discharge efficiency of the positive discharge is superior to that of the negative discharge. I have. Although not shown in FIG. 16 for ease of illustration, the dimensions are as described above, and the interval D3 is 15
mm, the voltage between the electrodes exceeds 12 kV and exceeds 25 kV.
It has been confirmed that the discharge current takes a higher value in the case of plus discharge than in the case of minus discharge even at V or less. When the voltage between the electrodes is in the range of 10 kV to 11 kV, the discharge efficiency is reversed between the positive discharge and the negative discharge. However, even when the power supply voltage is in the range of 9 kV to 10 kV, the discharge efficiency in the positive discharge is lower than that in the negative discharge. Although not significantly lower, and not shown, it has been confirmed that the same discharge characteristics are exhibited when the voltage between the electrodes is 8 kV or more and less than 9 kV.
Thus, when the interval D3 is 9 mm or more and 15 mm or less,
The power supply voltage is preferably 8 kV or more and 20 kV or less, and particularly when the distance D3 is 15 mm, the power supply voltage is 1 kV.
It is preferably 1 kV or more and 20 kV or less.

FIG. 17 is a graph showing dust collection efficiencies in positive discharge and negative discharge when the discharge electrode 1D is used. The horizontal axis indicates the power supply voltage, that is, the voltage between the electrodes, and the vertical axis indicates the dust collection efficiency, that is, the amount of fine particles in the gas near the inflow opening 27 and the outflow opening 28 of the electrostatic precipitator 10D using an optical sensor, respectively. And a dust collection rate determined from the amount of fine particles on the inlet side and the amount of fine particles on the outlet side. The first line 73 shows the relationship between the dust collection efficiency and the voltage between the electrodes in the positive discharge, and the second line 74 shows the relationship between the dust collection efficiency and the voltage between the electrodes in the negative discharge. As shown in the first line 73 and the second line 74, the discharge electrode 1
When each dimension of D is as described above, the voltage between the electrodes is 11
In the range of kV or more and 12 kV or less, the dust collection efficiency is higher in the positive discharge than in the negative discharge, corresponding to the discharge efficiency. Although not shown in FIG. 17 for ease of illustration, the dimensions are as described above, and the distance D3 is 15 m.
m, the voltage between the electrodes exceeds 12 kV and 25 kV
Also in the following cases, it has been confirmed that the dust collection efficiency takes a higher value in the case of positive discharge than in the case of negative discharge. When the voltage between the electrodes is in the range of 10 kV to 11 kV, the dust collection efficiency is reversed between the positive discharge and the negative discharge. However, the dust collection efficiency in the positive discharge does not fall significantly below the dust collection efficiency in the negative discharge, and is shown in the figure. Although not shown, it has been confirmed that the same dust collection efficiency characteristics are exhibited when the voltage between the electrodes is 8 kV or more and less than 10 kV.

[0072]

[Table 1]

Further, the discharge electrode 1D and the discharge electrode 1F in which each projection 3 projecting along the virtual plane 22 as shown in FIG. 13 is formed only at the end of the base 2 on the upstream side in the flow direction B (for easy understanding). It is also confirmed that a difference occurs in the dust collection efficiency. Specifically, the dust collector voltage, that is, the first and second dust collector electrodes 1
When a voltage of 5.5 kV is applied between 8, 19,
Comparing the dust collection efficiency when the charging section voltage, that is, the voltage between the discharge electrodes 1D and 1F and the counter electrode 17 is 11, 12, and 13 kV, the discharge electrode 1D in which each projection 3 is inclined from the virtual plane 22 is used. It can be seen that the dust collection efficiency is sometimes better than when the discharge electrode 1F is used. As is clear from these results, it is understood that the discharge electrode having excellent discharge efficiency exhibits excellent dust collection efficiency. The discharge electrode 1F
Needless to say, this is also the discharge electrode of the present invention.

The dust collection efficiencies shown in FIG. 17 and Table 1 are not limited to the above example, and are not shown. However, each projection 3 is formed at both ends in the flow direction B of the base 2. Also show the same tendency.

As described above, each projection 3 may be formed at both ends of the base 2 in the flow direction, or may be formed only at one end of the base 2 on the upstream side or the downstream side in the flow direction B. In any of these cases, the effect of the above-described positive discharge can be achieved, and the effect in the case where each projection 3 is formed to be inclined from the virtual plane 22 can be similarly achieved.

FIG. 18 is a graph showing the difference in discharge efficiency depending on the arrangement of the projections 3. The horizontal axis indicates the power supply voltage, that is, the voltage between the electrodes, and the vertical axis indicates the discharge current. FIG. 18 shows the relationship between the inter-electrode voltage and the discharge current when one discharge electrode 1D as shown in FIG. 15 is provided between the pair of opposed electrodes 17 on the first line 81. A discharge electrode 1E (a configuration not shown) is formed between a pair of opposing electrodes, at the upstream end of the base 2 in the flow direction B, each protrusion 3 having the same arrangement as the discharge electrode 1A shown in FIG. Shows the relationship between the inter-electrode voltage and the discharge current when one is provided. The third line 83 shows the relationship between the inter-electrode voltage and the discharge current when two discharge electrodes 1D are provided at intervals in the flow direction B between the pair of opposed electrodes 17, and the fourth line 84 shows The discharge current with respect to the inter-electrode voltage when two discharge electrodes 1E are provided at a distance in the flow direction B between a pair of opposed electrodes is shown.

As can be understood by comparing the first line 81 with the second line 82 and similarly comparing the third line 83 with the fourth line 84, the discharge electrode 1D Is more excellent in discharge efficiency than in the case of using the discharge electrode 1E. Further, in the discharge electrode 1E, spark discharge occurred at an inter-electrode voltage of 17 kV, whereas in the discharge electrode 1D, stable corona discharge was generated without transition to spark discharge even at an inter-electrode voltage of 17 kV. . In this regard, it can be seen that it is preferable that the projections 3 alternately project from both sides in the thickness direction. Also, it has been confirmed that the arrangement of the projections 3 such as the discharge electrode 1 or the discharge electrode 1D exhibits excellent discharge efficiency, as compared with the arrangement of the projections 3 as shown in FIG. Next, it is confirmed that the arrangement of the projections 3 is preferably the arrangement shown in the discharge electrode 1A or the discharge electrode 1E, and is the arrangement shown next in the discharge electrode 1B. Such a difference in discharge efficiency due to the arrangement of the protrusions 3 is due to a difference in mutual influence of electric lines of force concentrated on the adjacent protrusions 3. This is because the influence can be reduced. The discharge electrode 1
It goes without saying that E is also the discharge electrode of the present invention.

FIG. 19 is a side view showing a part of an electric precipitator 10G provided with a discharge electrode 1G according to another embodiment of the present invention, and corresponds to a part of the charging section 12 in FIG. This embodiment has a configuration similar to that of the embodiment described with reference to FIGS. 1 to 8. Corresponding portions are denoted by the same reference numerals, and only different configurations will be described. I do. The discharge electrode 1 has protrusions 3 formed on both sides in the width direction of the base 2, and the protrusions 3 are formed so as to protrude alternately on both sides of the virtual plane 22. Each protrusion 3 of the discharge electrode 1 </ b> G is formed in the flow direction of the base 2. Each of the protrusions 3 at the end on the upstream side B and each of the protrusions 3 at the end on the downstream side in the flow direction B are in a virtual plane 2 toward the tip 31.
The directions away from 2 are opposite to each other. Specifically, each projection 3 formed at the end of the base 2 on the upstream side in the flow direction B is formed to be inclined to one side with respect to the virtual plane 22 on the lower side in FIG. Each projection 3 formed at the end on the downstream side in the flow direction B is formed to be inclined to the other side with respect to the virtual plane 22 on the upper side in FIG.

In the present embodiment, each dimension is set, for example, as follows. Thickness W3 of base 2: 0.64 mm Width L1 of base 2: 11.5 mm Occupied width (set width) W2 of each projection 3: 0.94 mm Projection width W1 of each projection 3: 0.3 mm Projection height of each projection 3 Height H: 1.5 mm Pitch of each projection 3: 10 / inch Width L2 of discharge electrode 1: 13 mm Distance D3 between tip 31 and counter electrode 17: 15 mm

Even when the projection 3 is formed so as to be inclined and protruded only on one side and the other side of the virtual plane 22, the effect of the above-described triangular shape of each projection 3 is obtained. , And the effect of positive discharge can be achieved. Further, in this way, the protrusions 3 at the end in the flow direction B in the flow direction of the base 2 and the protrusions 3 on the downstream side in the flow direction B of the base 2 are formed so as to protrude in different directions from each other. 2 reduce the mutual influence between the lines of electric force concentrated on each protrusion 3 on the upstream side in the flow direction B of the base 2 and the lines of electric force concentrated on each protrusion 3 on the downstream side in the flow direction B of the base 2. The discharge between the protrusion 3 and the counter electrode 17 and the discharge between each of the downstream protrusions 3 and the counter electrode 17 are prevented from interfering with each other, and the discharge efficiency is improved. Accordingly, the width of the discharge electrode 1G can be reduced.

FIG. 20 is a simplified sectional view showing an electric precipitator 110 according to still another embodiment of the present invention.
This embodiment has a configuration similar to that of the embodiment described with reference to FIGS. 1 to 8. Corresponding portions are denoted by the same reference numerals, and only different configurations will be described. I do. The electrostatic precipitator 10 is a two-stage electric precipitator having a charging unit 12 and a precipitator 13.
Reference numeral 0 denotes a single-stage electric dust collector having only the dust collecting section 13. The discharge electrode 1 and the counter electrode 16 are provided in the flow path 29 in the housing 15 along the flow direction B. The opposing electrodes 16 have a flat plate shape and are arranged in parallel with each other at equal intervals in a direction perpendicular to the flow direction B. In the present embodiment, five opposing electrodes 16 are provided. Three discharge electrodes 1 are arranged between each counter electrode 16, and a total of 12 discharge electrodes 1 are provided. Each discharge electrode 1 has a configuration similar to that of the discharge electrode in the form shown in FIGS. 1 to 8, is arranged along a plane including the center between adjacent counter electrodes 17, and is spaced apart in the flow direction B. It is arranged. The distance L10 between the discharge electrodes 1 adjacent in the flow direction B is, for example, 20 mm.

The other dimensions are set, for example, as follows. Thickness W3 of base 2: 0.64 mm Width L1 of base 2: 10 mm Occupied width (set width) W2 of each projection 3: 1.24 mm Projection width W1 of each projection 3: 0.3 mm Projection height H of each projection 3 : 1.5 mm Pitch of each protrusion 3: 10 / inch Width L2 of discharge electrode 1: 13 mm Distance D3 between tip 31 and counter electrode 17: 15 mm

When a voltage is applied between the electrodes 1 and 17 by the power supply 20 serving as a discharge power supply and a power supply for forming an electric field, such an electrostatic precipitator 110 faces each projection 3 of each discharge electrode 1. Corona discharge occurs between the electrode 17 and
Thereby, the fine particles in the gas passing between the electrodes 1 and 17 are charged, and a DC electric field is formed between the base 2 of each discharge electrode 1 and the counter electrode 17, so that the charged fine particles are discharged. Dust is collected on the base 2 of the electrode 1 or the counter electrode 17 by Coulomb force.

Even with such a one-stage type electrostatic precipitator 110, the effect of making each protrusion 3 triangular as described above and the effect of positive discharge can be achieved. For example, instead of the discharge electrode 1 of the one-stage electric precipitator 110, the above-described discharge electrode 1D may be provided. The dust collection efficiency varies depending on the inclination from the top.

[0085]

[Table 2]

In such a single-stage electric precipitator 110, it has been confirmed that there is a difference in the dust collection efficiency between the discharge electrode 1D and the discharge electrode 1F. More specifically, when comparing the dust collection efficiency when the dust collection portion voltage, that is, the voltage between the discharge electrodes 1D and 1F and the counter electrode 17, is 8.0, 8.5, and 9.0 kV, each of the protrusions 3 When the discharge electrode 1D inclined from the virtual plane 22 is used, the discharge electrode 1D
It can be seen that dust collection efficiency was superior to that when F was used. As is clear from these results, in the single-stage electric precipitator, the discharge electrode having excellent discharge efficiency exhibits excellent dust collection efficiency. Needless to say, the discharge electrode 1F is also the discharge electrode of the present invention.

The present invention is not limited to the above embodiments, and the configuration can be changed. For example, each of the projections 3 of each of the discharge electrodes may be formed into a substantially right-angled triangle or a substantially acute-angled triangle in place of the shape projected onto the virtual plane 22 being a substantially obtuse triangle. In particular, when the shape projected on the virtual plane 22 is a right triangle, the first and second end faces corresponding to the sides protruding from the base face in the direction away from the base 2 as compared to the acute triangle. Alternatively, each projection 3 is perpendicular to the end of the base 2 and can be easily formed.

It goes without saying that the number of discharge electrodes, the dimensions of each part, and the like can be changed.

[0089]

According to the present invention, in the flow path through which gas flows,
A discharge electrode and a counter electrode are provided, and a voltage for generating corona discharge is applied between these electrodes by a corona discharge power supply. As a result, the gas passes between the electrodes, whereby the fine particles in the gas are charged, and the charged fine particles are collected by electrostatic force. As described above, the discharge electrode which generates corona discharge between the counter electrode and the counter electrode to charge the fine particles has a plurality of protrusions which are tapered from the base, and each protrusion protrudes closer to the counter electrode. Further, as the discharge electrode, a discharge electrode having a protrusion is used, and a voltage is applied so that the discharge electrode has a higher potential than the counter electrode, and a voltage is applied so that the counter electrode has a higher potential than the discharge electrode. In contrast, a large discharge current can be obtained between the electrode and the counter electrode, as compared with the same potential difference. Therefore, the operation efficiency of the electric dust collector can be improved.

Further, according to the present invention, a discharge electrode and a counter electrode are provided in the flow path in which gas flows, and a voltage for generating corona discharge is applied between these electrodes by a corona discharge power supply. As a result, the gas passes between the electrodes, whereby the fine particles in the gas are charged, and the charged fine particles are collected by electrostatic force. As described above, the discharge electrode that generates corona discharge between the counter electrode and the counter electrode in order to charge the fine particles has a plurality of protrusions that are tapered from the base. The corona discharge power supply applies a voltage so that the discharge electrode has a higher potential than the counter electrode. By using a discharge electrode having a projection and applying a voltage so that the discharge electrode has a higher potential than the counter electrode, compared to a case where a voltage is applied so that the counter electrode has a higher potential than the discharge electrode, A large discharge current can be obtained for the same voltage. Therefore, the operation efficiency of the electric precipitator is improved. The distance between the tip of each protrusion and the counter electrode is 5 mm or more and 30 mm or less, and the potential difference between the discharge electrode and the counter electrode is 5 kV or more and 25 kV or less. When the distance between the tip of each projection and the counter electrode is less than 5 mm, the density of the electrodes in the gas flow path increases, and the resistance to gas flow increases. When the distance exceeds 30 mm, corona discharge occurs. It hardly occurs, and the operation efficiency is reduced. Therefore, by setting the distance between the tip of each projection and the counter electrode in the above range, the resistance to the gas flow can be reduced, and corona discharge can be easily generated, so that the operation efficiency can be increased. In the case where the distance between the tip of each projection and the counter electrode is as described above, when the potential difference between the discharge electrode and the counter electrode is less than 8 kV, the discharge current is lower than when the counter electrode has a higher potential than the discharge electrode. When the discharge electrode has a higher potential than the counter electrode, the discharge current is significantly lower, and the potential difference is 25%.
If it exceeds kV, spark discharge is likely to occur.
Therefore, when the distance between the tip of each projection and the counter electrode is within the above range, by setting the potential difference between the discharge electrode and the counter electrode within the range, it is possible to obtain a high discharge current with respect to the selected discharge voltage. And the occurrence of spark discharge can be prevented.

According to the present invention, the potential difference between the discharge electrode and the counter electrode is 10 kV or more and 20 kV or less.
By further limiting the range of the potential difference in this manner, the discharge current when the discharge electrode has a higher potential than the counter electrode is less likely to be lower than the discharge current when the counter electrode has a higher potential than the discharge electrode. And the occurrence of spark discharge can be reliably prevented.

According to the present invention, the distance between the tip of each projection and the counter electrode is set to 20 mm, and the potential difference between the discharge electrode and the counter electrode is 14 kV or more and 20 kV or less.
When the distance between the tip of each projection and the counter electrode is as described above, the potential difference between the discharge electrode and the counter electrode is 14 kV.
If it is less than the discharge current when the potential of the discharge electrode is higher than the counter electrode, the discharge current may be lower than the discharge current when the potential of the counter electrode is higher than the discharge electrode, and the potential difference exceeds 20 kV. Then, spark discharge may occur. On the other hand, by setting the distance between the tip of each projection and the counter electrode to the above value and setting the potential difference between the discharge electrode and the counter electrode to the above range, it is possible to reliably obtain a high discharge current with respect to the selected discharge voltage. And the occurrence of spark discharge can be reliably prevented.

According to the present invention, the distance between the tip of each of the protrusions and the counter electrode is 9 mm or more and 15 mm or less, and the potential difference between the discharge electrode and the counter electrode is 11 kV or more and 20 k or more.
V or less. In the case where the distance between the tip of each protrusion and the counter electrode is as described above, when the potential difference between the discharge electrode and the counter electrode is less than 11 kV, the discharge current is lower than when the counter electrode has a higher potential than the discharge electrode. When the potential of the discharge electrode is higher than that of the counter electrode, the discharge current may be lower. When the potential difference exceeds 20 kV, spark discharge may occur. On the other hand, by setting the distance between the tip of each projection and the counter electrode to the above value and setting the potential difference between the discharge electrode and the counter electrode to the above range, it is possible to reliably obtain a high discharge current with respect to the selected discharge voltage. And the occurrence of spark discharge can be reliably prevented.

According to the present invention, each projection has a substantially triangular shape projected on an imaginary plane including the base, and the triangle has mutually different lengths of two sides projecting from the base.
That is, each projection projects obliquely from the base to the end of the base. Thereby, each protrusion has a higher tip height than the isosceles triangular protrusion as in the prior art, or without a shorter side connected to the base, and a sharper tip, that is, The angle of the tip can be reduced. Therefore, the tip is sharpened to improve the discharge efficiency, the charge rate of the fine particles is also improved, and the dust collection efficiency can be improved, and the mechanical strength of each projection is reduced, and the tip is prevented from being dissolved and oxidized. be able to. As described above, in the related art, the conflicting problems can be solved at the same time.

Each projection may be formed along the imaginary plane including the base, or may be formed so as to move away from the imaginary plane toward the tip.

Further, according to the present invention, the shape of each projection projected onto the virtual plane is a substantially right triangle, and the side connected to the base is a side other than the oblique side. The angle of the tip of each projection can be reduced, and the surface of the projection corresponding to the side protruding from the base faces in the direction away from the base, or is parallel to the direction away from the base, and It can be easily formed.

Further, according to the present invention, the shape of each projection projected onto the virtual plane is a substantially obtuse triangle, and the sides connected to the base are sides other than the obtuse pair. The angle of the tip of each projection can be made smaller than in the case of a triangle.

[Brief description of the drawings]

FIG. 1 is a plan view showing a part of a discharge electrode 1 according to an embodiment of the present invention.

FIG. 2 is a simplified cross-sectional view showing an electric precipitator 10 having the discharge electrode 1 of FIG.

FIG. 3 is a cross-sectional view taken along line III-III in FIG.

FIG. 4 is a perspective view seen from obliquely above left in FIG. 1;

FIG. 5 is a perspective view seen from obliquely below left in FIG. 1;

FIG. 6 is a side view showing a part as viewed from the left side of FIG. 2;

FIG. 7 is a graph showing the discharge efficiency of a discharge electrode 1 and a discharge line.

FIG. 8 is a graph showing discharge efficiency by positive discharge and negative discharge.

FIG. 9 is a cross-sectional view showing a discharge electrode 1A according to another embodiment of the present invention.

FIG. 10 is a side view showing a part of an electric precipitator 10A using a discharge electrode 1A.

FIG. 11 is a discharge electrode 1 according to still another embodiment of the present invention.
It is sectional drawing which shows B.

FIG. 12 is a side view showing a part of an electric precipitator 10B using a discharge electrode 1B.

FIG. 13 is a discharge electrode 1 according to still another embodiment of the present invention.
It is a side view which shows some electric dust collectors 10C using C.

FIG. 14 is a graph showing the discharge efficiency of the discharge electrode 1 and the discharge electrode 1C.

FIG. 15 is a discharge electrode 1 according to still another embodiment of the present invention.
It is a side view which shows a part of electric dust collector 10D using D.

FIG. 16 is a graph showing discharge efficiency of positive discharge and negative discharge when the discharge electrode 1D is used.

FIG. 17 is a graph showing dust collection efficiency of positive discharge and negative discharge when the discharge electrode 1D is used.

FIG. 18 is a graph showing discharge efficiency of a discharge electrode 1D and a discharge electrode 1E.

FIG. 19 is a discharge electrode 1 according to still another embodiment of the present invention.
It is a side view which shows a part of electric dust collector 10G using G.

FIG. 20 is a simplified cross-sectional view showing an electric dust collector 110 according to still another embodiment of the present invention.

[Explanation of symbols]

 1, 1A to 1G Discharge electrode 2 Base 3 Projection 4 Triangle 5 First end face 6 Second end face 10, 10A to 10D, 110 Electric precipitator 21 Housing 17 Counter electrode 18, 19 Precipitator electrode 20, 21 Power supply

Claims (8)

(57) [Claims] 1. A gas flow direction is provided from a gas flow direction end of a base provided in a flow path through which a gas containing particulate matter to be collected flows and extending along a direction intersecting the gas flow direction. A discharge electrode in which a plurality of protrusions projecting in a tapered shape are formed, and a counter electrode disposed on both sides in a direction perpendicular to the gas flow direction from the discharge electrode in the gas flow path, A corona discharge power supply that generates a corona discharge between each protrusion of the discharge electrode and the counter electrode, and applies a voltage so that the discharge electrode has a higher potential than the counter electrode. The discharge electrode has a protrusion protruding so as to approach one of the opposing electrodes on both sides of the electrode. The discharge electrode compares the electric potential difference between the discharge electrode and the opposing electrode with the same electric potential difference, and Than when the potential is higher than When the discharge electrode and a higher potential than the counter electrode, an electrostatic precipitator, characterized in that it is obtained a large discharge current between the counter electrode. 2. A gas flow direction from a gas flow direction end of a base provided in a flow path through which a gas containing particulate matter to be collected flows and extending along a direction intersecting the gas flow direction. A discharge electrode formed with a plurality of protrusions that project in a tapered shape along the line; a counter electrode disposed in the gas flow path at intervals in a direction perpendicular to a gas flow direction from the discharge electrode; A corona discharge power supply that generates a corona discharge between each protrusion of the electrode and the counter electrode, and applies a voltage so that the discharge electrode has a higher potential than the counter electrode; and a tip of each protrusion and a counter electrode. The distance in the direction perpendicular to the virtual plane including the base is 5 mm or more and 30 mm or less, and the corona discharge power supply applies a voltage so that the potential difference between the discharge electrode and the counter electrode is 5 kV or more and 25 kV or less. It is characterized by That the electrostatic precipitator. 3. The electrostatic precipitator according to claim 1, wherein the corona discharge power supply applies a voltage so that a potential difference between the discharge electrode and the counter electrode becomes 10 kV or more and 20 kV or less. 4. A distance between a tip of each of the projections and a counter electrode in a direction perpendicular to an imaginary plane including the base is 20 mm, and a power supply for corona discharge has a potential difference between the discharge electrode and the counter electrode of 14 kV. 3. The electric precipitator according to claim 1, wherein a voltage is applied so as to be not less than 20 kV. 5. An interval between a tip of each projection and a counter electrode in a direction perpendicular to an imaginary plane including the base is 9 mm or more and 15
3 mm or less, and the corona discharge power supply applies a voltage so that the potential difference between the discharge electrode and the counter electrode is 8 kV or more and 20 kV or less. 6. The projection of each of the projections on a virtual plane including the base is substantially a triangle, and the triangles have mutually different lengths of two sides projecting from the base. The electric dust collector according to any one of claims 1 to 5. 7. The electrostatic precipitator according to claim 6, wherein the shape of each of the projections projected on the virtual plane is a substantially right triangle, and the side connected to the base is a side other than the oblique side. . 8. The electric collector according to claim 6, wherein the shape of each of the projections projected onto the virtual plane is a substantially obtuse triangle, and the side connected to the base is a side other than the opposite side of the obtuse angle. Dust equipment.