CN108025317A - Electric precipitation machine and waste gas cleaning system - Google Patents

Abstract

When the discharge electrode has a spike-shaped protrusion, corona discharge is generated between the spike-shaped protrusion of the discharge electrode and the counter electrode. Therefore, if the electrostatic precipitator is operated for a long time, erosion of the counter electrode may occur at a specific point of the counter electrode corresponding to the spike-shaped protrusion. The present invention provides an electric precipitator, comprising: a first electrode plate; and a second electrode plate opposite to the first electrode plate and having an end located inside the end of the first electrode plate, the end of the second electrode plate Does not have protruding parts.

Description

Electrostatic precipitator and exhaust gas purification system

technical field

The invention relates to an electric dust collector and an exhaust gas purification system.

Electrostatic precipitators are used to collect particles in exhaust gases in various areas such as in various factory buildings and in flues. Conventionally, in an electrostatic precipitator in which a flat discharge electrode and a flat counter electrode face each other, the discharge electrode has a spike-shaped protruding portion at the end like a sawtooth knife (for example, refer to Patent Document 1). The discharge electrode generates a corona discharge between the spike-shaped protruding portion and the counter electrode, and the particles are charged by the corona discharge. The dust removal electrode collects charged fine particles by Coulomb force (for example, refer to Patent Document 1).

prior art literature

patent documents

Patent Document 1: Specification of Japanese Patent No. 2971461

Contents of the invention

The technical problem to be solved by the invention

Corona discharge is generated between the spike-shaped protruding portion of the discharge electrode and the counter electrode. Therefore, if the electrostatic precipitator is operated for a long time, erosion of the counter electrode may occur at a specific point of the counter electrode corresponding to the spike-shaped protrusion.

Technical solutions adopted to solve technical problems

(General Disclosure of the Invention) The electrostatic precipitator may include a first electrode plate and a second electrode plate. The second electrode plate may be disposed opposite to the first electrode plate. The end of the second electrode plate may be located inside the end of the first electrode plate. An end portion of the second electrode plate may not have a protruding portion.

The second electrode plate may be in the shape of a flat plate. The second electrode plate may have a radius of curvature equal to or more than half of a gap between the first electrode plate and the second electrode plate in all regions.

The second electrode plate may have a flat plate shape including a straight portion and a corner portion having a radius of curvature.

The second electrode plate may be in the shape of a circular plate.

The second electrode plate may have one or more through openings.

The one or more through-openings may include a plurality of independent through-openings.

The one or more through openings may have a central opening and a peripheral opening. The central opening may be the largest. The opening area of the peripheral opening may be smaller than that of the central opening. The peripheral opening may be arranged around the central opening.

The second electrode plate may have one or more through openings. At least one of the one or more through openings may have an edge protruding toward the first electrode plate.

There may be a plurality of through-openings having edge portions protruding toward the first electrode plate. The protruding length of the edge may be different between the upstream side and the downstream side of the gas introduced into the electrostatic precipitator.

The protruding length of the edge portion may be made longer on the upstream side than on the downstream side.

The first unit having the first electrode plate and the second electrode plate may be stacked in plural.

The length of the gap between the first electrode plate and the second electrode plate at the end portion of the stacking direction of the first unit in which a plurality of units are stacked can be made longer than the center portion in the stacking direction of the first unit in which a plurality of units are stacked. The length of the gap between the first electrode plate and the second electrode plate.

The electrostatic precipitator may further include a second unit. The second unit may have a third electrode plate and a fourth electrode plate. The fourth electrode plate may be disposed opposite to the third electrode plate. An end of the fourth electrode plate may be located inside an end of the third electrode plate. An end portion of the fourth electrode plate may have a protruding portion. The second unit may be provided at least at both ends in the stacking direction of the stacked first unit.

The exhaust gas cleaning system may include a scrubber as well as an electrostatic precipitator as described above. The scrubber can clean the exhaust gas. An electrostatic precipitator can be located upstream of the scrubber.

In addition, the above summary of the invention does not list all desirable features of the invention. Furthermore, modifications of these feature groups can also be inventions.

Description of drawings

FIG. 1 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 1. As shown in FIG.

FIG. 2 is a cross-sectional view showing the configuration of an electrostatic precipitator 200 according to Embodiment 1. FIG.

Fig. 3 is a diagram obtained by A-A' section in top view 2.

FIG. 4 is a diagram showing the shape of discharge electrode 100 according to the second embodiment.

FIG. 5 is a diagram showing the shape of discharge electrode 100 according to the third embodiment.

FIG. 6 is a diagram showing the shape of discharge electrode 100 according to Embodiment 4. FIG.

FIG. 7 is a diagram showing the shape of discharge electrode 100 according to Embodiment 5. FIG.

FIG. 8 is a diagram showing the shape of discharge electrode 100 according to Embodiment 6. FIG.

FIG. 9 is a diagram showing the shape of discharge electrode 100 according to Embodiment 7. FIG.

FIG. 10 is a diagram showing the shape of discharge electrode 100 according to the eighth embodiment.

FIG. 11 is a cross-sectional view of discharge electrode 100 according to Embodiment 8 viewed from a side direction.

FIG. 12 is a diagram showing the shape of discharge electrode 100 according to Embodiment 9. FIG.

FIG. 13 is a cross-sectional view of discharge electrode 100 according to Embodiment 9 viewed from a side direction.

FIG. 14 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 10. FIG.

FIG. 15 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 11. FIG.

FIG. 16 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 12. FIG.

FIG. 17 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 13. FIG.

FIG. 18 is a diagram showing an outline of an exhaust gas purification system 400 .

Detailed ways

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the inventions within the scope of the claims. Furthermore, all combinations of the features described in the embodiments are not necessarily essential to the solution means of the invention.

In this specification, the technical content is described using rectangular coordinate axes of the X axis, the Y axis, and the Z axis. The Cartesian coordinate axis only determines the relative position of the constituent elements, and does not limit a specific direction. For example, the Z axis is not limited to be expressed as a height direction relative to the ground. In addition, the +Z-axis direction and the -Z-axis direction are mutually opposite directions. In the case where the Z-axis direction is described without indicating the plus or minus, it refers to directions parallel to the +Z-axis and the -Z-axis. In addition, in this specification, a "straight line" has an infinite radius of curvature.

FIG. 1 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 1. As shown in FIG. The electrostatic precipitator 200 collects particulates in the exhaust gas. Particles are smoke and dust. The electrostatic precipitator 200 has a counter electrode 10 - 1 and a discharge electrode 100 . The counter electrode 10 - 1 as the first electrode plate is an electrode plate at the GND potential, and is also referred to as a GND electrode. The discharge electrode 100 as the second electrode plate is a high-potential electrode plate. The discharge electrode 100 is provided opposite to the counter electrode 10-1.

The electrostatic precipitator 200 of this embodiment has a counter electrode 10-2 in addition to the counter electrode 10-1 and the discharge electrode 100. Counter electrode 10 - 1 and counter electrode 10 - 2 are disposed so as to sandwich discharge electrode 100 . Accordingly, corona discharge 2 can be generated at the end portions 102 on both surfaces of one discharge electrode 100 . However, unlike the present embodiment, the electrostatic precipitator 200 may be constituted only by the counter electrode 10 - 1 and the discharge electrode 100 .

The opposite electrode 10-1, the discharge electrode 100, and the opposite electrode 10-2 may be stacked in the Z direction so that the gap length from the discharge electrode 100 to the opposite electrode 10-1 in the Z direction is the same as that from the discharge electrode 100 to the opposite electrode 10-1. The gap lengths in the Z direction of the electrodes 10-2 are equal. The counter electrode 10-1, the counter electrode 10-2, and the discharge electrode 100 can be arranged parallel to the XY plane.

Counter electrode 10 - 1 and counter electrode 10 - 2 (hereinafter sometimes referred to as counter electrode 10 ) and discharge electrode 100 have a flat plate shape. The thickness of the counter electrode 10 and the discharge electrode 100 may be not less than 1 mm and not more than 2 mm. The plate area of the counter electrode 10 and the discharge electrode 100 may be not less than 0.3 m ² and not more than 3 m ² . For example, the counter electrode 10 and the discharge electrode 100 are flat plates of approximately 1 m×1 m. Here, the area of the discharge electrode 100 is smaller than the area of the counter electrode 10 . The material of the counter electrode 10 and the discharge electrode 100 may be stainless steel such as SUS304 according to JIS standards.

The opposite electrode 10 in this embodiment is rectangular. The counter electrode 10 of this embodiment has an end portion 12 . The end portion 12 comprises four sides 14 of a rectangle. Here, the "end" refers to an end in a direction parallel to the XY plane. However, unlike this embodiment, the counter electrode 10 may have any shape such as a polygon, a circle, and an ellipse. The discharge electrode 100 of the present embodiment has a shape that can be approximated as a rectangle. The discharge electrode 100 has an end 102 . The end portion 102 of the discharge electrode 100 is located inside the end portion 12 of the counter electrode 10 . As shown in FIG. 1 , the end 102 of the discharge electrode 100 does not include protruding parts such as spikes.

A negative high voltage is applied to the discharge electrode 100 in this embodiment through the DC power supply 20 . The counter electrode 10 is grounded. Thus, a high electric field region is formed between the discharge electrode 100 and the counter electrode 10 .

When the discharge electrode 100 has a protruding portion such as a spike shape unlike the present embodiment, the generation position of the corona discharge 2 is easily fixed at a position directly below or directly above the protruding portion. If the electrostatic precipitator 200 is operated for a long period of time, particles such as dust tend to locally accumulate on the counter electrode 10 at the position directly below or directly above the protruding portion of the discharge electrode 100 . The accumulation of fine particles shortens the gap length between the discharge electrode 100 and the counter electrode 10 . As a result, the portion where the gap length is shortened has a higher electric field than other portions, and easily exceeds the electric field required for conversion to spark (spark discharge). When sparks are generated, the counter electrode 10 is likely to be corroded.

In addition, when charged particles are adsorbed and accumulated on the opposite electrode 10 having a different potential, a back discharge will occur. If the generation position of the corona discharge 2 is fixed and the charged particles are locally deposited at the fixed position, reverse discharge will be generated at the fixed position. If the reverse discharge always occurs at a fixed position, the counter electrode 10 may be locally damaged. In order to suppress this state, it is necessary to periodically clean the discharge electrode 100 and the counter electrode 10 to remove particles, which increases the burden of maintenance.

On the other hand, according to the present embodiment, since the discharge electrode 100 has no protruding portion, the generation position of the corona discharge 2 is not fixed to a specific point. Therefore, the corona discharge 2 can be generated in the entire linear region corresponding to the side of the end portion 102 of the discharge electrode 100 . When the corona discharge 2 is formed in a dot shape, the dot of the corona discharge 2 is not fixed at one place, but can move within the area on the line. Accordingly, it is possible to prevent local erosion of the counter electrode 10 from occurring. In addition, even if the electrostatic precipitator 200 is operated for a long time, local accumulation of fine particles such as dust on the discharge electrode 100 and the counter electrode 10 can be suppressed. As a result, it is possible to prevent the change in the gap length between the discharge electrode 100 and the counter electrode 10 due to accumulation of fine particles, thereby suppressing the generation of sparks. In addition, the effects of reverse discharge are also mitigated, since localized particle buildup no longer occurs.

FIG. 2 is a cross-sectional view showing the configuration of an electrostatic precipitator 200 according to Embodiment 1. FIG. The particles in the exhaust gas are negatively charged between the discharge electrode 100 and the counter electrode 10 due to the corona discharge 2 . The negatively charged particles are collected by the counter electrode 10 by Coulomb force.

Fig. 3 shows a diagram obtained by section A-A' in top view 2. Discharge electrode 100 includes straight line portion 104 and corner portion 106 as end portion 102 . "The case where the end portion 102 of the discharge electrode 100 does not have a protruding portion" includes cases where the end portion 102 of the discharge electrode 100 can be approximated to a polygon such as a quadrangle, a pentagon, or a hexagon. The end portion 102 of the discharge electrode 100 may have a shape obtained by connecting a straight line portion 104 corresponding to a polygonal side and a corner portion 106 in which the vertex portion is smoothed by a curved line. The corner portion 106 has a radius of curvature equal to or greater than half of the gap length d between the counter electrode 10 and the discharge electrode 100 . The discharge electrode 100 of the present embodiment has a radius of curvature equal to or more than half of the gap length d over the entire area.

All the corners 106 of the discharge electrode 100 may have a Rogowski electrode shape approximately in an arc shape. Accordingly, the electric field concentration on the corner portion 106 can be alleviated. The Rogowski electrode is an electrode that forms a quasi-uniform electric field having substantially the same magnitude in the corner portion 106 and the straight portion 104 . According to the discharge electrode 100 of this embodiment, the end effect (edge effect) of the parallel plate electrodes can be alleviated to form a quasi-uniform electric field, and the corona discharge 2 can be prevented from concentrating on one corner 106 of the discharge electrode 100 .

FIG. 4 is a diagram showing the shape of discharge electrode 100 according to the second embodiment. Similar to Fig. 3 , a view taken along the A-A' cross section in plan view 2 is shown. Compared with the electrostatic precipitator 200 of Embodiment 1, the electrostatic precipitator 200 of Embodiment 2 is the same except for the shape of the discharge electrode 100. As shown in FIG. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals. The discharge electrode 100 in this embodiment is rectangular. R chamfering is applied to the corner portion 106 . Therefore, the manufacturing process of the discharge electrode 100 can be simplified.

In this embodiment, the end portion 102 of the discharge electrode 100 also does not have a protruding portion. In the present embodiment, the end portion 102 of the discharge electrode 100 does not need to have a radius of curvature equal to or more than half the gap length d in all regions. Compared with the case where the discharge electrode 100 has a protruding portion such as a spike shape, the discharge electrode 100 of this embodiment can also reduce the phenomenon that the generation position of the corona discharge 2 is fixed. In addition, unlike this embodiment, the shape of the discharge electrode 100 may be a convex polygon such as a pentagon or a hexagon without R-chamfering.

FIG. 5 is a diagram showing the shape of discharge electrode 100 according to the third embodiment. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electrostatic precipitator 200 of Embodiment 3 is the same as the electrostatic precipitator 200 of Embodiment 1 and Embodiment 2 except for the shape of the discharge electrode 100 . Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

The discharge electrode 100 of this embodiment is in the shape of a disc. That is, the end 102 of the discharge electrode 100 is circular. "The case where the end 102 of the discharge electrode 100 does not have a protruding part" includes the case where the end 102 of the discharge electrode 100 is formed by a closed curve such as a circle or an ellipse. In this embodiment, the radius of the discharge electrode 100 is larger than the gap length d between the counter electrode 10 and the discharge electrode 100 in the Z direction. Therefore, the discharge electrode 100 has a radius of curvature equal to or more than half of the gap length d over the entire area.

According to the present embodiment, the end portion 102 of the discharge electrode 100 is formed of curved lines having the same curvature radius. Therefore, the generated electric field is substantially the same regardless of the position on the end portion 102 . Accordingly, corona discharge 2 can be uniformly generated over the entire end portion 102 of the discharge electrode 100 without being affected by the corner portion 106 . When the corona discharge 2 is formed in a point shape, the point of the corona discharge 2 is not fixed at one place, but can move randomly along the circular end portion 102 . Therefore, generation of sparks can be suppressed, and corrosion of the discharge electrode 100 can be slowed down.

FIG. 6 is a diagram showing the shape of discharge electrode 100 according to Embodiment 4. FIG. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electric precipitator 200 of Embodiment 4 is the same as the electric precipitator 200 of Embodiment 1 except that the discharge electrode 100 has the through opening 110 . Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

The edge portion 112 of the through opening portion 110 may have a polygonal shape with R-chamfered vertices. The edge portion 112 includes a linear edge portion 114 corresponding to the four sides of a rectangle, and a corner edge portion 116 in which apexes are smoothed with curved lines. The corner edge portion 116 has a radius of curvature equal to or greater than half of the gap length d between the counter electrode 10 and the discharge electrode 100 . Therefore, the discharge electrode 100 of this embodiment has a radius of curvature equal to or more than half the gap length d not only at the end portion 102 but also in the entire region including the central region including the edge portion 112 of the through opening 110. .

In this embodiment, if a high electric field region is formed between the discharge electrode 100 and the counter electrode 10, the corona discharge 2 can be generated not only at the end 102 of the discharge electrode 100, but also at the edge 112 of the through opening 110. Corona discharge 2. Therefore, by using the discharge electrode 100 having the through opening 110 , the number of locations where the corona discharge 2 is generated can be increased compared to the case of using the discharge electrode 100 not having the through opening 110 . Therefore, this Example can improve the dust collection amount per unit area (dust collection efficiency) of the electrostatic precipitator 200 compared with Embodiment 1 - Embodiment 3.

FIG. 6 shows a case where both the end portion 102 of the discharge electrode 100 and the edge portion 112 of the through-opening 110 have a polygonal shape with R-chamfered vertices. However, the discharge electrode 100 of this embodiment is not limited to this case, and may have a through opening 110 having a shape different from that of the end 102 of the discharge electrode 100 .

FIG. 7 is a diagram showing the shape of discharge electrode 100 according to Embodiment 5. FIG. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electrostatic precipitator 200 of Embodiment 5 is the same as the electrostatic precipitator 200 of Embodiment 3 except that the discharge electrode 100 has the through-opening 110 . Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

In this embodiment, the edge portion 112 of the through opening portion 110 is circular. Different from this embodiment, the edge portion 122 of the through opening portion 110 may adopt an oval shape or other shapes. Therefore, compared with the case of using the discharge electrode 100 without the through-opening 110 , in the present embodiment, by using the discharge electrode 100 having the through-opening 110 , the number of locations where the corona discharge 2 is generated can be increased.

FIG. 8 is a diagram showing the shape of discharge electrode 100 according to Embodiment 6. FIG. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electrostatic precipitator 200 of Embodiment 6 is the same as the electrostatic precipitator 200 of Embodiment 5 except that the shape of the discharge electrode 100 and the shape of the through opening 110 are different. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

The discharge electrode 100 of the present embodiment is arranged in a plurality of concentric annular portions. Specifically, the discharge electrode 100 has a first annular portion 101 and a second annular portion 103 arranged inside the first annular portion 101 . A first opening 111 which is an annular opening is provided between the first annular portion 101 and the second annular portion 103 . A second opening 113 , which is a circular opening, is provided inside the second annular portion 103 . In other words, the discharge electrode 100 of this embodiment has the first opening 111 and the second opening 113 as a plurality of independent through openings 110 .

The end 102 of the first annular portion 101 in this embodiment corresponds to the outer circumference of the first annular portion 101 and becomes the end 102 of the discharge electrode 100 . The outer circumference of the first annular portion 101 has a radius equal to or more than half the gap length d. The first edge portion 115 , which is an edge portion of the first opening portion 111 , corresponds to the inner circumference of the first annular portion 101 and the outer circumference of the second annular portion 103 . The inner circumference of the first annular portion 101 and the outer circumference of the second annular portion 103 have a radius equal to or greater than half the gap length d. The edge portion of the second opening portion 113 , that is, the second edge portion 117 corresponds to the inner circumference of the second annular portion 103 . The inner circumference of the second annular portion 103 also has a radius equal to or greater than half the gap length d. Therefore, the discharge electrode 100 of this embodiment has a radius of curvature equal to or more than half of the gap length d not only at the end portion 102 but also in the entire region including the central region.

The discharge electrode 100 of this embodiment includes a plurality of independent through openings 110 . Thereby, compared with the case where there is one through opening 110, the number of locations where corona discharge 2 is generated can be increased.

FIG. 9 is a diagram showing the shape of discharge electrode 100 according to Embodiment 7. FIG. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electrostatic precipitator 200 of Embodiment 7 is the same as the electrostatic precipitator 200 of Embodiment 4 except that the shape of the discharge electrode 100 and the shape and number of the through openings 110 are different. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

The discharge electrode 100 of this embodiment has a plurality of independent through openings 110 . The through opening 110 may have a central opening 140 and a plurality of peripheral openings 146 . In this embodiment, there is one central opening 140 and four peripheral openings 146 . The central opening 140 has the largest opening area among the plurality of through openings 110 . The opening area of each peripheral opening 146 is smaller than that of the central opening 140 . Each peripheral opening 146 is arranged around the central opening 140 .

In this embodiment, the edge portion of the central opening 140 , that is, the central edge portion 122 has a circular shape. The peripheral edge portion 123 , which is the edge portion of the peripheral opening portion 146 , has a polygonal shape in which apexes are smoothed. However, the shapes of the central edge portion 122 and the peripheral edge portion 123 are not limited to this case. The discharge electrode 100 has a curvature radius equal to or more than half of the gap length d in the entire region including the central edge portion 122 and the peripheral edge portion 123 not only at the end portion 102 .

Generally, the electric field concentrates on the end portion 102 of the discharge electrode 100 , and the electric field is less likely to concentrate on the central portion inside the discharge electrode 100 . Therefore, in the central portion inside the discharge electrode 100 , the area not having a high electric field becomes large. However, according to the discharge electrode 100 of the present embodiment, the central opening 140 located inside the discharge electrode 100 can be made larger than the peripheral opening 146 . As a result, the electric field intensity increases in the central edge portion 122 which is the edge portion of the central opening 140 , and corona discharge 2 can also be generated in the central portion of the discharge electrode 100 .

FIG. 10 is a diagram showing the shape of discharge electrode 100 according to the eighth embodiment. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. The electrostatic precipitator 200 of the eighth embodiment is the same as the electric precipitator 200 of the fourth embodiment except for the shape and number of the through openings 110 and the protrusion of the edge 112 of the through openings 110 . Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

The discharge electrode 100 of this embodiment has a total of four through openings 110 arranged in two rows and two columns on the X-Y plane. However, the number of through openings 110 is not limited to this case, and may be different from this embodiment. The discharge electrode 100 of this embodiment has a radius of curvature equal to or more than half of the gap length d not only at the end 102 of the discharge electrode 100 but also in the entire region including the edge 112 of the through opening 110 .

FIG. 11 is a cross-sectional view of discharge electrode 100 according to Embodiment 8 viewed from a side direction. Specifically, Fig. 11 is a sectional view showing the B-B' section in Fig. 10 . In discharge electrode 100 of this embodiment, through opening 110 has edge 112 protruding toward counter electrode 10 . The protruding length of the edge portion 112 is q.

In this embodiment, the edge portions 112 of the plurality of through openings 110 protrude. However, unlike this embodiment, at least one of the plurality of through openings 110 may have an edge 112 protruding toward the counter electrode 10 . In addition, one through opening 110 may be provided, and the one through opening 110 has an edge 112 protruding toward the counter electrode 10 . The discharge electrode 100 can be formed by machining such as press working so that the edge portion 112 of the through opening 110 protrudes. According to the discharge electrode 100 of this embodiment, the corona discharge 2 can be generated more easily than the case where the edge portion 112 does not protrude.

FIG. 12 is a diagram showing the shape of discharge electrode 100 according to Embodiment 9. FIG. Similar to Fig. 3 , a view taken along the A-A' cross section in Plan View 2 is shown. Compared with the electrostatic precipitator 200 of the eighth embodiment, the electrostatic precipitator 200 according to Embodiment 9 differs in the protruding length of the edge portion 112 of the through opening 110 depending on the position in the X direction, and the edge portion 112 of the through opening 110 is not It is the same except that R chamfering is performed on the vertex. However, the edge portion 112 of the through opening portion 110 may be chamfered at the apex. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals. The discharge electrode 100 of this embodiment has a total of nine through openings 110 arranged in three rows and three columns on the X-Y plane. However, the number of through openings 110 is not limited to this case, and may be different from this embodiment.

FIG. 13 is a cross-sectional view of discharge electrode 100 according to Embodiment 9 viewed from a side direction. Specifically, Fig. 13 is a cross-sectional view showing a C-C' cross-section in Fig. 12 . The exhaust gas introduced into the electrostatic precipitator 200 flows in the X direction. The discharge electrode 100 of the present embodiment has a plurality of through openings 100 having edge portions 112 protruding toward the counter electrode 10 . In the discharge electrode 100 of this embodiment, the protruding length of the edge portion 112 of the through opening portion 110 is different between the upstream side and the downstream side of the exhaust gas. Thereby, the easiness of generation of the corona discharge 2 at the upstream and downstream of the exhaust gas can be changed.

In this embodiment, three rows of through openings 110 are arranged along the X direction. The length by which the edge portion 112 protrudes through the opening portion 110 is q1 at the upstream, q2 at the midstream, and q3 at the downstream. As shown in Figure 13, q1 is the longest, q3 is the shortest, and q2 is the length between q1 and q3. That is, the protruding length of the edge portion 112 is longer on the upstream side than on the downstream side.

By making the protruding length of the edge portion 112 longer on the upstream side than on the downstream side, the corona discharge 2 can be generated more easily on the upstream side than on the downstream side. Thereby, dust collection is easier in the upstream area than in the downstream area. The concentration of fine particles contained in the exhaust gas is highest in the upstream region, and becomes lower toward the downstream region. Therefore, according to this embodiment, dust can be efficiently collected on the upstream side where the particle concentration is higher than the downstream side.

However, unlike this embodiment, the protruding length of the edge portion 112 penetrating through the opening 110 can be made longer on the downstream side than on the upstream side to improve the dust collection performance on the downstream side. Thereby, it is possible to prevent the particles from rapidly accumulating on the upstream side, and it is possible to reduce the variation in particle deposition between the upstream side and the downstream side. Therefore, an increase in maintenance burden for removing fine particles can be suppressed.

FIG. 14 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 10. FIG. The electrostatic precipitator 200 of this embodiment has a structure in which a plurality of first units 210 having the counter electrode 10 and the discharge electrode 100 are stacked. In other words, the electrostatic precipitator 200 of this embodiment has redundancy in the vertical direction. One first cell 210 is formed by one counter electrode 10 and one discharge electrode 100 . In this embodiment, the gap lengths between adjacent electrodes may all be the same.

In this embodiment, the opposite electrode 10 - 1 and the discharge electrode 100 - 1 form a first unit 210 . Likewise, the opposite electrode 10 - 2 and the discharge electrode 100 - 2 constitute a first unit 210 . The opposite electrode 10 - 3 and the discharge electrode 100 - 3 constitute a first unit 210 . In this embodiment, three first units 210 are stacked in the Z direction. However, the number of stacked first units 210 is not limited to this case, and the number of stacked units may be four or more.

In this embodiment, among the discharge electrode 100-1, the discharge electrode 100-2, and the discharge electrode 100-3, a single counter electrode 10-4 is disposed opposite to the discharge electrode 100-3 located at the upper end in the stacking direction. A single counter electrode 10-4 may also be omitted.

The counter electrodes 10 - 1 to 10 - 4 (hereinafter sometimes referred to as counter electrodes 10 ) may be the counter electrodes 10 described in Embodiments 1 to 9 above. Discharge electrode 100-1 to discharge electrode 100-3 (hereinafter may be referred to as discharge electrode 100) may be discharge electrode 100 described in Embodiments 1 to 9 above. Therefore, detailed descriptions of the counter electrode 10 and the discharge electrode 100 are omitted.

According to this Example, since the some 1st unit 210 is laminated|stacked, dust collection efficiency can be improved compared with the case of one unit. When a plurality of 1st cells are stacked, each discharge electrode 100 which comprises 1st cell 210 does not have protrusions, such as a spike shape, either. Therefore, it is possible to prevent the generation position of the corona discharge 2 from being fixed.

FIG. 15 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 11. FIG. The electrostatic precipitator 200 of this embodiment is similar in structure to the electric precipitator 200 of Embodiment 10 except that the length of the gap between the counter electrode 10 and the discharge electrode 100 differs depending on the position of the first unit 210 in the stacking direction. same. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

In this embodiment, the stacking direction of the first unit 210 is the Z direction. The discharge electrode 100-3 is located in the upper end part of Z direction among the discharge electrode 100-1 - the discharge electrode 100-3. The discharge electrode 100-3 is paired with the counter electrode 10-3. The opposite electrode 10 - 3 and the discharge electrode 100 - 3 constitute the first cell 210 . In this embodiment, the gap length d2 between the opposing electrode 10-3 and the discharge electrode 100-3 refers to the gap length between the opposing electrode 10-3 and the discharge electrode 100-3 at the upper end in the Z direction.

On the other hand, the gap length d1 between the opposing electrode 10-2 and the discharge electrode 100-2 refers to the gap length between the opposing electrode 10-3 and the discharge electrode 100-3 in the center part of Z direction. In this embodiment, the gap length d2 between the opposite electrode 10-3 and the discharge electrode 100-3 refers to the gap length d1 between the opposite electrode 10-2 and the discharge electrode 100-2.

In this embodiment, the discharge electrode 100-1 is located at the lower end in the Z direction among the discharge electrodes 100-1 to 100-3. The length of the gap between the counter electrode 10-1 and the discharge electrode 100-1 in the lower end portion in the stacking direction of the stacked first cells 210 is also d2. Therefore, in this embodiment, the gap length d2 of the upper end portion and the lower end portion in the Z direction is larger than the gap length d1 of the center portion in the Z direction. However, unlike the present embodiment, the length of the gap at either the upper end portion or the lower end portion in the Z direction may be made larger than the central portion.

In this embodiment, each discharge electrode 100 is equal to the gap length between two adjacent opposite electrodes 10 . Specifically, the gap length between the discharge electrode 100-1 and the opposite electrode 10-1 is equal to the gap length between the discharge electrode 100-1 and the opposite electrode 10-2, which is d2. The gap length between the discharge electrode 100-2 and the opposite electrode 10-2 is equal to the gap length between the discharge electrode 100-2 and the opposite electrode 10-3, which is d1. The gap length between the discharge electrode 100-3 and the opposite electrode 10-3 is equal to the gap length between the discharge electrode 100-3 and the opposite electrode 10-4, which is d2.

However, unlike this embodiment, the gap lengths between each of the discharge electrodes 100 and two adjacent counter electrodes 10 may be different from each other. Specifically, the gap between the opposite electrode 10 and the discharge electrode 100 on the side closer to the end in the Z direction among two adjacent opposite electrodes 10 can be increased.

From the point of view of making the gap length on the side near the lower end in the Z direction greater than the gap length at the central portion, the gap length between the discharge electrode 100-1 and the opposite electrode 10-1 may also be greater than that between the discharge electrode 100-1 and the opposite electrode 10-1. Gap length between opposing electrodes 10-2. From the point of view of making the gap length on the side near the upper end in the Z direction greater than the gap length at the center, the gap length between the discharge electrode 100-3 and the opposite electrode 10-4 can also be greater than the gap length between the discharge electrode 100-3 and the opposite electrode 10-4. Gap length between opposing electrodes 10-3.

In this embodiment, the case where three first units 210 are stacked is described, but unlike this embodiment, four or more first units 210 may be stacked. In this case, the gap length between the counter electrode 10 and the discharge electrode 100 can be gradually increased from the center to the upper end or the lower end in the Z direction.

In the case where a plurality of first units 210 are stacked to form a stacked structure, it is difficult for exhaust gas to flow at the ends of the first units 210 in the stacking direction. However, in the electrostatic precipitator 200 of the present example, dust collection can be facilitated by increasing the gap length at the ends of the stacking direction of the first units 210 .

FIG. 16 is a perspective view showing the configuration of an electrostatic precipitator 200 according to Embodiment 12. FIG. In the electrostatic precipitator 200 of this embodiment, the second unit 220 is provided at least at both ends in the Z direction. Except this point, the structure of the electrostatic precipitator 200 of this Example is the same as the structure of the electrostatic precipitator 200 of Embodiment 10. FIG. Therefore, repeated descriptions of other structures are omitted, and the same components are described using the same reference numerals.

In this embodiment, a plurality of first units 210 are stacked at the center in the Z direction. In this embodiment, two first units 210 are stacked. However, unlike this embodiment, three or more first units 210 may be stacked. The structure of the first unit 210 is the same as that of the tenth embodiment. On the other hand, at least two end portions in the Z direction are provided with second units 220 .

At the lower end in the Z direction, the second cell 220 has an end counter electrode 190-1 and a protruding discharge electrode 180-1. The end counter electrode 190 - 1 as the third electrode plate is an electrode plate at the GND potential, and is also referred to as a GND electrode. The protruding discharge electrode 180-1 as the fourth electrode plate is a high potential electrode plate. The protruding discharge electrode 180-1 is provided opposite to the end counter electrode 190-1. The protruding discharge electrode 180-1 and the end counter electrode 190-1 may be arranged parallel to the XY plane.

The end portion 182 of the protruding discharge electrode 180-1 is located inside the end portion 192 of the end portion opposing electrode 190-1. Here, the end portion 182 refers to an end portion in a direction parallel to the XY plane. A negative high voltage is applied to the protruding discharge electrode 180 - 1 of this embodiment through the DC power supply 20 . The end counter electrode 190-1 is grounded.

As shown in FIG. 16 , the end portion 182 of the protrusion type discharge electrode 180 - 1 has a protruding portion 184 . The projected shape of the protruding portion 184 on the XY plane may have a triangular shape. The protruding portion 184 in this embodiment is in the shape of a spike or a serrated knife. The protrusions 184 are provided in plural along the end 182 . The protruding portion 184 may have a protruding length of 1 mm to 5 mm. The pitch can be determined so that 3 or more and 5 or less protrusions 184 are provided per 1 cm. In the end portion 182 of the protruding discharge electrode 180-1, the protruding portion 184 may be provided along all sides, or may be provided only along a specific side.

At the upper end in the Z direction, the second cell 220 has an end counter electrode 190-2 and a protruding discharge electrode 180-2. The end opposing electrode 190-2 is a third electrode plate, and the protruding discharge electrode 180-2 is a fourth electrode plate. The structure and applied voltage of the second unit 220 at the upper end in the Z direction may be the same as that of the second unit 220 arranged at the lower end.

In this embodiment, one second unit 220 is respectively provided at both ends in the Z direction. However, unlike the present embodiment, a plurality of second units 220 may be respectively provided at the upper end and the lower end in the Z direction. Here, the first unit 210 is stacked at the center in the stacking direction. The stacking number of the second unit 220 is preferably not more than the stacking number of the first unit 210 .

When a plurality of units are stacked to form a stacked structure, at the end of the stacking method of the units, the flow of exhaust gas is difficult, so the number of deposits such as particles is also smaller than that at the center of the stacked structure. Therefore, even if the conventional protruding discharge electrode 180 having the spike-shaped protruding portion 184 is used in the end portion of the lamination method, the possibility of sparks caused by deposits is lower than that in the central portion of the lamination structure. For this reason, conventional protruding discharge electrodes 180 having spike-shaped protruding portions 184 can be used at least at both ends in the stacking direction, and the first unit without the spike-shaped protruding portion 184 can be stacked at the center of the stacking direction. 210 to actively reduce sparking.

FIG. 17 is a diagram showing an electrostatic precipitator 200 according to Embodiment 13. The electrostatic precipitator 200 of the thirteenth embodiment is the same as the electric precipitator 200 of the first to twelfth embodiments except that a positive high voltage is applied to the discharge electrode 100 by the DC power supply 20 . In Embodiments 1 to 12, the counter electrode 10 (or the end part counter electrode 190 ) is grounded, and a negative high voltage is applied to the discharge electrode 100 . On the other hand, in this embodiment, a positive high voltage is applied instead of the negative high voltage in Embodiments 1 to 12.

In the case of applying a positive high voltage to the discharge electrode 100 by the DC power supply 20, since the end 102 of the discharge electrode 100 does not have a protruding portion, it is also possible to prevent the corona discharge from being fixed at just below or directly below the protruding portion. above. Accordingly, corrosion of the counter electrode can be suppressed.

FIG. 18 is a diagram showing an outline of an exhaust gas purification system 400 . The exhaust gas purification system 400 removes harmful substances such as sulfur components contained in exhaust gas discharged from an engine of a vehicle or the like. The exhaust gas cleaning system 400 has an electric precipitator 200 , a scrubber 300 , and a suction pump 350 . The electrostatic precipitator 200 is installed upstream of the scrubber 300 . Exhaust gas is introduced from the electrostatic precipitator 200 to the scrubber 300 through the exhaust gas introduction pipe 306 . As the electrostatic precipitator 200, the electric precipitator 200 of Embodiment 1-13 mentioned above is used.

The scrubber 300 has a reaction tower 302 , a nozzle 304 , and an exhaust gas introduction pipe 306 . The reaction tower 302 has an internal space extending in the height direction. The height direction in this embodiment refers to the direction extending from the bottom side 308 where the exhaust gas is introduced to the upper side 310 where the exhaust gas is discharged in the reaction tower 302 .

In the scrubber 300 , the exhaust gas introduction pipe 306 is located near the bottom side 308 of the reaction tower 302 . The exhaust gas introduction pipe 306 may also be provided so that the exhaust gas introduced from the exhaust gas introduction pipe 306 spirally surrounds the inner side of the reaction tower 302 . The radius of the reaction tower 302 may be not less than 0.3 m and not more than 10 m.

Inside the washer 300, a washing water pipe 312 through which washing water flows is arranged. In the present embodiment, a cleaning water pipe 312 is disposed near the upper side 310 of the reaction tower 302 . The washing water pipe 312 of this embodiment conveys washing water in a direction perpendicular to the height direction of the reaction tower 302 . Wash water is supplied from suction pump 350 to wash water pipe 312 .

A nozzle 304 is provided on the washing water pipe 312 . The nozzle 304 sprays washing water 314 onto the exhaust gas from the upper side 310 toward the bottom side 308 to treat the exhaust gas. The washing water 314 sprayed from the nozzle 304 contacts the exhaust gas passing through the inside of the reaction tower 302 to absorb sulfur components and the like contained in the exhaust gas. The liquid absorbing sulfur components and the like is stored in the bottom side 308 of the reaction tower 302 and discharged to the outside of the reaction tower 302 as waste water.

According to the exhaust gas purification system 400 of this embodiment, harmful substances that cannot be removed by the electrostatic precipitator 200 can be removed. Since the electrostatic precipitator 200 of the first to thirteenth embodiments is used in the exhaust gas purification system 400, erosion of the counter electrode 10 due to the fixed generation position of the corona discharge 2 can be suppressed.

In addition, the above-described embodiment can also be applied to a two-stage electrostatic precipitator in which a charging unit and a dust collecting unit are separately configured.

As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range described in said embodiment. It is obvious to those skilled in the art that various changes and improvements can be added to the above-described embodiment. It is clear from the description of the patent claims that the above-mentioned various changes or improvements are also included in the technical scope of the present invention.

Label description

2 Corona discharge

10 Counter electrode

12 ends

14 sides

20 DC power supply

100 discharge electrodes

101 First Ring

102 ends

103 Second ring part

104 Straight line

106 Corner

110 Through opening

111 First opening

112 edge

113 Second opening

114 Straight edge

115 First edge

116 corner edge

117 Second edge

122 Central edge

123 peripheral edge

140 central opening

146 Perimeter opening

180 Protruding Discharge Electrodes

182 ends

184 overhang

190 Opposite Electrodes

192 ends

200 Electrostatic precipitator

210 Unit 1

220 Unit 2

300 Scrubber

302 reaction tower

304 nozzle

306 Exhaust gas introduction pipe

308 bottom side

310 upper side

312 Clean water pipe

314 washing water

350 suction pump

400 exhaust gas purification system

Claims (14)

1. An electrostatic precipitator, characterized in that, comprising: a first electrode plate; and a second electrode plate, the second electrode plate is disposed opposite to the first electrode plate, and the end portion is located inside the end portion of the first electrode plate, The end portion of the second electrode plate has no protruding portion. 2. The electrostatic precipitator according to claim 1, characterized in that, the second electrode plate is a flat plate shape, The second electrode plate has a radius of curvature equal to or more than half of a gap between the first electrode plate and the second electrode plate in all regions. 3 . The electrostatic precipitator according to claim 2 , wherein the second electrode plate has a flat plate shape including a straight portion and a corner portion having the radius of curvature. 4 . 4. The electrostatic precipitator according to claim 2, wherein the second electrode plate is in the shape of a circular plate. 5. The electrostatic precipitator according to any one of claims 1 to 4, wherein the second electrode plate has one or more through openings. 6. The electrostatic precipitator according to claim 5, wherein the one or more through openings include a plurality of independent through openings. 7. The electrostatic precipitator according to claim 6, wherein the one or more through openings have: a central opening having the largest open area; and A peripheral opening having an opening area smaller than that of the central opening and arranged around the central opening. 8. The electrostatic precipitator according to claim 1, wherein the second electrode plate has more than one through opening, At least one of the one or more through openings has an edge protruding toward the first electrode plate. 9. The electrostatic precipitator according to claim 8, wherein there are a plurality of through-openings having edge portions protruding toward the first electrode plate, The protruding length of the edge portion is different between the upstream side and the downstream side of the gas introduced into the electrostatic precipitator. 10. The electrostatic precipitator according to claim 9, wherein the protruding length of the edge portion is longer on the upstream side than on the downstream side. 11. The electrostatic precipitator according to any one of claims 1 to 10, wherein a plurality of first units having the first electrode plate and the second electrode plate are stacked. 12. The electrostatic precipitator according to claim 11, wherein a plurality of the first electrode plate and the second electrode plate are stacked at the ends of the stacking direction of the first unit. The gap length therebetween is greater than the gap length between the first electrode plate and the second electrode plate in the center portion in the stacking direction of the first unit stacked in plurality. 13. The electrostatic precipitator according to claim 11, further comprising a second unit having: a third electrode plate; and a fourth electrode plate, the fourth electrode plate is disposed opposite to the third electrode plate, the end portion is located inside the end portion of the third electrode plate, and the end portion has a protruding portion, The second unit is provided at least at both ends in a stacking direction of the stacked first unit. 14. An exhaust gas purification system, characterized in that it comprises: a scrubber, which purifies the exhaust gas; and The electrostatic precipitator according to any one of claims 1 to 13, which is installed upstream of the scrubber.