WO2008068823A1

WO2008068823A1 - Moving electrode of electrostatic precipitator

Info

Publication number: WO2008068823A1
Application number: PCT/JP2006/324097
Authority: WO
Inventors: Yoshihiko Mochizuki; Toshiyuki Eguchi
Original assignee: Hitachi Plant Technologies, Ltd.
Priority date: 2006-12-01
Filing date: 2006-12-01
Publication date: 2008-06-12

Abstract

The number of components is decreased by increasing the width per sheet of collecting electrode plate, and a portion for coupling the collecting electrode plate to an endless cable is made compact. In the moving electrode of an electrostatic precipitator which comprises a pair of drive wheels (20) arranged above, a pair of driven rollers (22) arranged below, a pair of endless chains (24) stretched to connect the drive wheels (20) with the driven rollers (22), and a plurality of sheets of collecting electrode plate (26) coupled with the pair of endless chains (24), and which is arranged to allow the plurality of sheets of collecting electrode plate (26) to move around a discharge pole, wherein each collecting electrode plate (26) is coupled, at the upper end position thereof, with the endless chain (24) to rotate freely, and the drive wheel (20) is supported by a cantilever shaft (30) from the outside of the moving region of the collecting electrode plate (26).

Description

Specification

Moving electrode of electric dust collector

Technical field

TECHNICAL FIELD [0001] The present invention relates to a moving electrode of an electrostatic precipitator, and more particularly, to an electrostatic precipitator in which a plurality of dust collecting plates connected to an endless strip are moved around a discharge electrode. It relates to a moving electrode.

Background art

In order to remove dust from boiler exhaust gas from thermal power plants and exhaust gas power from various furnaces, a moving electrode type electrostatic precipitator as disclosed in Patent Document 1 may be used. Fig. 6 is a perspective view showing a schematic structure of a moving electrode used in this type of moving electrode type electrostatic precipitator. A pair of endless chains 3, 3 are rotatably stretched between a pair of driving sprocket wheels 1 arranged at the upper part and a pair of driven rollers 2 arranged at the lower part. A plurality of dust collecting electrode plates 4, 4,... Are connected between the pair of endless chains 3, 3 by fixing the center position of the side edge to the connecting portion 5. The shaft 6 of the drive sprocket wheel 1 is rotated by a drive mechanism (not shown), and the rotation of the shaft 6 is transmitted to a pair of endless chains 3 and 3 that mesh with the drive sprocket wheel 1 to form a loop as a whole. A plurality of dust collecting electrode plates 4, 4,... Move around a discharge electrode (not shown).

FIG. 7 is a layout view of the lower part of the moving electrode 10, and the dust collecting electrode plate 4 lowered and suspended by the endless chain 3 makes a U-turn at the position of the driven roller 2 and starts to rise. A rotating brush 7 is disposed for each lane of the moving electrode 10 at a position sandwiching the dust collecting electrode plate 4 immediately after the ascent. A discharge electrode 8 is disposed above the rotary brush 7. While the dust collecting plates 4 and 4 move up and down the sides of the discharge electrodes 8, the dust in the exhaust gas is charged by corona discharge from the discharge electrodes 8 and collected on the surface of each dust collection plate 4 Is done. When each dust collecting electrode plate 4 passes through the position where the rotating brush 7 is disposed, the dust adhering to the surface of the dust collecting electrode plate 4 is peeled off and removed by the rotating brush 7.

[0004] That is, in this type of moving electrode type electrostatic precipitator, the upper collector where the discharge electrode 8 exists is present. While each dust collecting electrode plate 4 moves in the dust space, dust is collected on the surface of each dust collecting electrode plate 4, and this dust collecting electrode plate 4 descends and makes a U-turn at the position of driven roller 2. The dust that adheres to the surface of the dust collecting electrode plate 4 when it starts to rise is repeatedly peeled off and removed by the rotating brush 7. According to such a configuration, every time the dust collecting electrode plate 4 passes through the rotating brush 7, dust adhering to the surface of the dust collecting electrode plate 4 is surely removed, and the cleanliness of the surface of the dust collecting electrode plate 4 is ensured. Recovers. For this reason, the thickness of the dust layer collected and deposited on the surface of the dust collecting electrode plate 4 can always be kept thin.

[0005] The dust collection performance of the electrostatic precipitator is greatly affected by the electrical resistivity of the collected dust.

In particular, when the electrical resistivity of dust is as high as 10 ¹² Ωcm or more, the reverse ionization phenomenon occurs when the thickness of the dust layer deposited on the surface of the dust collection electrode plate exceeds a certain value, and the dust collection performance decreases rapidly. I will give you. In the moving electrode type electrostatic precipitator, the thickness of the dust layer collected and deposited on the surface of the dust collecting electrode plate 4 can always be kept thin as described above, so that the reverse ionization phenomenon hardly occurs. Therefore, this type of moving electrode type electrostatic precipitator is mainly used for exhaust gas containing high resistance dust.

Patent Document 1: Japanese Patent Laid-Open No. 2001-246284

Disclosure of the invention

Problems to be solved by the invention

[0006] However, the moving electrode 10 having the above structure has a structure in which the dust collecting electrode plate 4 is fixed to the endless chain 3 by the connecting portion 5 at an intermediate position of the side edge portion thereof. The structure had to be strong and heavy enough to withstand the load on the electrode plate 4.

[0007] In addition, the moving electrode type electrostatic precipitator configured as described above moves so that the dust collecting electrode plate 4 moves at an equal distance with respect to the discharge electrodes 8 arranged in parallel at a pitch D as shown in FIG. An electrode is placed. Therefore, the outer diameter of the drive sprocket wheel 1 and the driven roller 2 constituting the moving electrode 10 and the distance between the moving electrodes 10 are also arranged in accordance with the pitch D.

In such an arrangement, both ends of the dust collecting electrode plate 4 when the dust collecting electrode plate 4 makes a U-turn at the positions of the drive sprocket wheel 1 and the driven roller 2 are indicated by two-dot chain lines in FIG. Draw a movement trajectory X. When the movement lanes X of adjacent lanes cross, adjacent dust collecting electrode plates 4 may collide with each other. For this reason, the width W of the dust collecting electrode plate 4 is limited, and it is usually necessary to keep its geometrical relational force below about Route 3 (1.73) D. For this reason, the dust collector plate 4 The dimensional force per sheet has been reduced, and the number of parts has increased accordingly, leading to an increase in cost.

[0009] The object of the present invention is to improve the above-mentioned drawbacks of the prior art, increase the width per dust collecting electrode plate to reduce the number of parts, and connect the dust collecting electrode plate to an endless strip. Another object of the present invention is to provide a moving electrode for an electrostatic precipitator that has a compact connecting portion.

Means for solving the problem

In order to achieve the above object, a moving electrode of an electrostatic precipitator according to the present invention includes a pair of upper rollers disposed above, a pair of lower rollers disposed below, A pair of endless cords stretched so as to connect the lower roller and the lower roller, and a plurality of dust collecting electrode plates connected to the pair of endless cords, The dust collecting plate is moved to the moving electrode of the electrostatic precipitator in which the dust collecting plate is moved around the discharge electrode, so that each dust collecting plate is positioned higher than the center of gravity with respect to the endless strip. The upper roller is supported by a cantilever shaft in the moving region external force of the dust collecting electrode plate. Note that the endless cable body is formed in a loop shape by connecting the end of a continuous cable such as a wire rope in addition to an endless chain that connects the ends of the chain to form a loop. It is a broad concept that includes

[0011] Further, the moving electrode of the electrostatic precipitator according to the present invention includes an inclination detection sensor that detects an inclination of each dust collecting electrode plate, and each cantilever of the upper roller in accordance with the detection of the inclination detection sensor. And a control means for controlling the number of rotations of the shaft.

Further, the moving electrode of the electrostatic precipitator according to the present invention is provided with a drive mechanism that is connected to each cantilever shaft of the upper roller and rotates each cantilever shaft in the same direction and at the same rotation speed. Features.

[0012] A rotation shaft is provided adjacent to the cantilever shaft, and the rotation is transmitted by a transmission mechanism that transmits the rotation of the rotation shaft to the cantilever shaft.

The lower roller is connected by a single drive shaft, and a rotational drive source is connected to the drive shaft.

The invention's effect

[0013] According to the moving electrode of the present invention, a plurality of dust collecting electrode plates are disposed on the endless cable body from the center of gravity. It is rotatably connected to the endless cable body at a high position. In addition, the upper roller is supported by the external force of the moving area of the dust collecting electrode plate and the cantilever shaft. For this reason, each dust collecting electrode plate always moves stably while maintaining a state in which it hangs down vertically due to its own weight.

[0014] Therefore, even when the dust collecting electrode plates of adjacent lanes pass through the upper roller and the lower roller, there is no possibility that the dust collecting electrode plates collide with each other. In addition, since the upper roller is supported by the external force cantilever shaft of the dust collecting plate, the cantilever shaft does not become an obstacle when each suspended dust collecting plate passes through the upper roller. . For this reason, the width w of the dust collecting electrode plate can be increased to reduce the number of parts. Further, since it is not necessary to firmly fix the dust collecting electrode plate to the endless cable body, it is only necessary to connect the dust collecting electrode plate so as to be freely rotatable, so that the connecting portion can have a compact structure.

[0015] In addition, comprising an inclination detection sensor for detecting the inclination of each dust collecting electrode plate, and a control means for controlling the number of rotations of each cantilever shaft of the upper roller according to the detection of the inclination detection sensor, It is possible to avoid the trouble that the dust collecting electrode plate is inclined due to the difference in the moving speed of the endless cord.

[0016] In addition, when a drive mechanism is provided that is connected to each cantilever shaft of the upper roller and rotates each cantilever shaft in the same direction and at the same rotation speed, the movement speeds of the pair of endless cords are matched. Therefore, troubles that each dust collecting electrode plate tilts can be avoided.

If a rotation shaft is provided adjacent to the cantilever shaft and rotation is transmitted by a transmission mechanism for transmitting rotation of the rotation shaft, the pair of endless chains Since the moving speed can be matched with 24, it is possible to prevent each dust collecting electrode plate 26 connected to the endless chain 24 from being greatly inclined and causing inoperability.

If the lower roller is connected by a single drive shaft and a rotational drive source is connected to this drive shaft, the drive wheel can be directly connected by the rotary shaft, and the drive system is simplified. it can.

Brief Description of Drawings

FIG. 1 is a schematic perspective view showing a first embodiment of a moving electrode according to the present invention.

FIG. 2 is a front view showing a main configuration of a moving electrode type electrostatic precipitator equipped with a moving electrode according to the present invention. FIG. 3 is a schematic side view showing a second embodiment of the moving electrode according to the present invention.

FIG. 4 is a schematic side view showing a third embodiment of a moving electrode according to the present invention.

FIG. 5 is a schematic side view showing a fourth embodiment of a moving electrode according to the present invention.

FIG. 6 is a perspective view showing a schematic structure of a moving electrode according to the prior art.

FIG. 7 is a layout view of a lower part of a moving electrode according to the prior art.

FIG. 8 is a schematic side view for explaining problems of the moving electrode according to the prior art.

Explanation of symbols

[0019] 18 moving electrode, 20, 20A drive wheel, 22, 22A driven roller

, 24 Endless chain, 26 Dust collector electrode plate, 28 Connecting part, 30 Cantilever shaft, 32 Drive mechanism, 34 Discharge electrode, 36 Rotating brush, 38 Tilt detection sensor, 40 Controller, 42 Rotation speed adjusting means, 44 Cantilever Shaft, 46 first sprocket, 48 second sprocket, 50 rotating shaft, 52 ……

… Drive mechanism, 54 sprocket chain, 56 rotary shaft, 58 drive mechanism, 60 cantilever shaft.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a schematic perspective view showing a first embodiment of the moving electrode of the electrostatic precipitator according to the present invention. A pair of endless chains 24, 24 are rotatably stretched between a pair of driving wheels 20, 20 arranged at the upper part and a pair of driven rollers 22, 22 arranged at the lower part. A plurality of rectangular dust collecting electrode plates 26, 26,... Are connected to the pair of endless chains 24, 24 at their upper end positions so that they can freely rotate around a horizontal axis by a connecting portion 28. In FIG. 1, for convenience of explanation, some of the dust collecting electrode plates 26 are not shown.

The drive wheels 20 and 20 are supported by cantilever shafts 30 and 30 from outside the moving region of the dust collecting electrode plates 26 and 26, respectively, and are driven to rotate by drive mechanisms 32 and 32, respectively. The rotation of the drive wheels 20 and 20 is transmitted to a pair of endless chains 24 and 24, and a plurality of dust collecting electrode plates 26, 26,. Move times. FIG. 2 is a front view showing a main configuration of a moving electrode type electrostatic precipitator including the moving electrode 18 having the above-described configuration. In the dust collection space, a plurality of discharge electrodes 34, 34,... Are arranged in parallel at predetermined intervals, and a plurality of moving electrodes 18 are arranged so as to surround every other discharge electrode 34. The dust collecting electrode plate 26, which is connected to the endless chain 24 and descends, moves upward while maintaining the state where it is suspended in the vertical direction by its own weight even at the position of the driven roller 22. A rotating brush 36 is arranged for each lane of the moving electrode 18 at a position sandwiching the dust collecting electrode plate 26 immediately after the ascent.

[0023] A gas to be treated containing high-resistance dust flows in a direction perpendicular to the paper surface. While the dust collecting plates 26 and 26 move up and down the side of the discharge electrode 34 in the dust collection space above the rotating brush 36, the dust being treated is charged by corona discharge from the discharge electrode 34, and It is collected on the surface of each dust collecting electrode plate 26. When each dust collecting electrode plate 26 passes through the position where the rotating brush 36 is disposed, the dust adhering to the surface of the dust collecting electrode plate 26 is peeled off and removed by the rotating brush 36.

[0024] That is, in this type of moving electrode type electrostatic precipitator, each dust collecting plate 26 moves in the upper dust collecting space where the discharge electrode 34 exists while keeping each dust collecting plate 26 in a vertical state. Dust is collected on the surface of the electrode plate 26. Immediately after the dust collecting electrode plate 26 descends and starts to move upward from the position of the driven roller 22, the dust attached to the surface of the dust collecting electrode plate 26 is removed by the rotating brush 36. Repeat stripping and removing. Even when the dust collecting electrode plate 26 rises and passes through the drive wheel 20, the dust collecting electrode plate 26 moves downward while maintaining a state in which the dust collecting electrode plate 26 hangs down vertically.

[0025] As described above, according to the moving electrode 18 of the present embodiment, the endless chains 24, 24, which are endless strips, have a plurality of dust collecting electrode plates 26, 26,. In the position, it is rotatably connected by the connecting portion 28. Further, the drive wheel 20 which is the upper roller is supported by the cantilever shaft 30 also in the moving region external force of the dust collecting electrode plate 26. For this reason, each dust collecting electrode plate 26 always moves stably while maintaining a state where it hangs down in the vertical direction by its own weight.

Therefore, even when the dust collecting electrode plates 26 of adjacent lanes pass through the drive wheel 20 and the driven roller 22, there is no possibility that the dust collecting electrode plates 26 collide with each other. Further, since the drive wheel 20 is also supported by the cantilever shaft 30 in the moving region of the dust collection electrode plate 26, the cantilever shaft 26 is moved when each dust collection electrode plate 26 that has dropped is passed through the drive wheel 20. 30 is an obstacle There is nothing. For this reason, the width W of the dust collecting electrode plate 26 can be increased to reduce the number of parts. Further, the connecting portion 28 does not need to firmly fix the dust collecting electrode plate 26, and it is sufficient to simply connect the dust collecting electrode plate 26 to the endless chains 24, 24 so that it has a compact structure. be able to.

In the moving electrode 18 having the above-described configuration, the pair of drive wheels 20 are rotationally driven by separate drive mechanisms 32. For this reason, there is a possibility that the rotational speeds of the pair of drive wheels 20 may not match due to shaft slip of the electric motor constituting the drive mechanism 32 or the like. If the rotational speeds of the drive wheels 20 do not match, there is a difference in moving speed between the pair of endless chains 24 driven by the rotation of the drive wheels 20, and each dust collecting electrode plate 26 connected to the endless chain 24 There is a risk of inclining and driving impossible.

FIG. 3 is an explanatory diagram showing the configuration of the second embodiment for avoiding the above trouble. The moving electrode 18 includes an inclination detection sensor 38 for detecting the inclination of the moving dust collection electrode plate 26, and the detection result of the inclination detection sensor 38 is transmitted to the controller 40. The controller 40 controls at least one of the rotational speed adjusting means (for example, an inverter) 42 attached to the drive mechanisms 32 and 32 so that the dust collecting electrode plate 26 is not inclined.

FIG. 4 is a schematic side view showing a third embodiment of the moving electrode of the electrostatic precipitator according to the present invention. In FIG. 4, elements having the same reference numerals as those in FIG. 1 have the same configurations and functions as those described in the first embodiment, and the description thereof is omitted. The cantilever shaft 44 according to the present embodiment includes a first sprocket 46 in addition to the drive wheel 20. A rotary shaft 50 having a pair of second sprockets 48 is disposed above the drive wheel 20, and the rotary shaft 50 is rotationally driven by a drive mechanism 52. A mechanism for transmitting the rotation of the rotating shaft 50 is provided. That is, each first sprocket 46 and each second sprocket 48 are connected by the sprocket chain 54. Therefore, the drive power of the drive mechanism 52 is transmitted in the order of the rotary shaft 50, the second sprocket 48, the first sprocket 46, the cantilever shaft 44, and the drive wheel 20, and the pair of drive wheels 20, 20 are in the same direction. , Rotate at the same speed. For this reason, since the moving speed can be matched with the pair of endless chains 24, it is not necessary to take a trouble avoidance measure as shown in FIG.

FIG. 5 is a schematic side view showing a fourth embodiment of the moving electrode of the electrostatic precipitator according to the present invention. FIG. In FIG. 5, elements denoted by the same reference numerals as those in FIG. 1 have the same configurations and functions as the elements described in the first embodiment, and description thereof is omitted. In the present embodiment, a pair of driven rollers 22A and 22A as lower rollers are coupled by a single rotational drive shaft, and a rotational drive source is connected to the rotational drive shaft. That is, in contrast to the first embodiment, the pair of drive wheels 20A, 20A are disposed at the lower part, and the pair of driven rollers 22A, 22A are disposed at the upper part. The pair of drive wheels 20A, 20A are connected by a rotation shaft 56, and the rotation shaft 56 is driven to rotate by a drive mechanism 58.

[0031] Each driven roller 22A, 22A is supported by a moving region external force of dust collecting electrode plate 26 and cantilever shafts 60, 60, respectively. A plurality of dust collecting electrode plates 26, 26,... Are rotatably connected to the pair of endless chains 24, 24 by a connecting portion 28 at an intermediate position higher than the center of gravity.

[0032] According to the moving electrode of the fourth embodiment, the drive wheels 20A, 20A are arranged in the lower part. For this reason, the drive wheels 20A and 20A can be directly connected by the rotating shaft 56, and the drive system can be simplified. Further, since the connecting portion 28 of the dust collecting electrode plate 26 is provided at the upper part of the intermediate position and at the lower part of the upper end, the dust collecting electrode plate 26 can be used when the width W of the dust collecting electrode plate 26 is the same. The lower end height of the dust collection electrode plate 26 when passing through the drive wheel 20A and the driven roller 22A can be increased, which helps to improve the space efficiency of the moving electrode.

Claims

The scope of the claims

[1] A pair of upper rollers disposed above, a pair of lower rollers disposed below, and a pair of endless cords stretched so as to connect the upper rollers and the lower rollers. A plurality of dust collecting plates connected to the pair of endless cords, and the plurality of dust collecting plates are moved around the discharge electrode. In the moving electrode, each dust collecting electrode plate is rotatably connected to the endless cable body at a position higher than its center of gravity, and each upper roller is cantilevered in the moving region of the dust collecting electrode plate. A moving electrode of an electrostatic precipitator characterized by being supported by a shaft.

[2] An inclination detection sensor for detecting the inclination of each dust collecting electrode plate and a control means for controlling the number of rotations of each cantilever shaft of the upper roller according to the detection of the inclination detection sensor. The moving electrode of the electrostatic precipitator according to claim 1.

[3] The electric collector according to claim 1, further comprising a drive mechanism that is connected to each cantilever shaft of the upper roller and rotates each cantilever shaft in the same direction and at the same rotation speed. The moving electrode of the dust device.

4. The rotating shaft is provided adjacent to the cantilever shaft, and the rotation is transmitted by a transmission mechanism for transmitting the rotation of the rotating shaft to the cantilever shaft. The moving electrode of the electrostatic precipitator described.

5. The moving electrode of the electrostatic precipitator according to claim 1, wherein the lower roller is connected by a single drive shaft, and a rotational drive source is connected to the drive shaft.