WO2008068822A1

WO2008068822A1 - Moving electrode of electrostatic precipitator

Info

Publication number: WO2008068822A1
Application number: PCT/JP2006/324096
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

A moving electrode of an electrostatic precipitator having endless ropes for supporting dust collecting electrode plates which do not cause elongation due to wear and have a prolonged life. The moving electrode (18) comprises a pair of endless ropes which are respectively rotatably supported by a pair of driving wheels (20) and dust collecting electrode plates (26) supported by the pair of endless ropes. The dust collecting electrode plates (26) revolve in a specified direction around a discharging electrode. The moving electrode is characterized in that flexible endless wires (24) are used as the endless ropes. It is desirable that engaging step parts are formed with a pitch on the outer circumference of the driving wheels (20), and engageable blocks which are engageable with the engaging step parts are attached to the endless wires (24) with a pitch.

Description

Specification

Moving electrode of electric dust collector

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 suspended on 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. 8 is a perspective view showing a schematic structure of a moving electrode used in this type of moving electrode type electrostatic precipitator. Between the pair of drive sprocket wheels 1 arranged at the upper part and the pair of driven rollers 2 arranged at the lower part, a pair of endless chains 3 and 3 are stretched so as to be rotatable as endless cords. . Between the pair of endless chains 3 and 3, a rectangular dust collecting electrode plate 4 is attached by being connected at the middle portion 5 of the side edge, and a plurality of dust collecting electrode plates 4, 4, and 4 are installed along the circumferential direction of the chain. ... are attached so that they are arranged. 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 meshing 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. 9 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

By the way, in the moving electrode 10 described above, a conductive material is used for the endless chain 3, and the current from each dust collecting electrode plate 4 is grounded from the endless chain 3 via the drive sprocket wheel 1 and the driven roller 2. Entangled. For this reason, dust adheres to the endless chain 3 in the same manner as each dust collecting electrode plate 4. The dust adhering to the endless chain 3 constitutes the endless chain 3 shown in FIG. 10, and enters the contact portion 3c between the horizontal link 3a and the vertical link 3b. When the endless chain 3 passes through the drive sprocket wheel 1 and the driven roller 2, the contact portion 3c slides, so the contact surfaces of the horizontal link 3a and the vertical link 3b are affected by the dust that has entered the contact portion 3c. Wear quickly. If the wear continues for a long period of time, the endless chain 3 gradually grows and the pitch P increases. The elongation of the endless chain 3 is directly linked to shortening the chain life. In addition, the increase in the pitch p has a drawback in that the endless chain 3 and the drive sprocket wheel 1 are not properly matched, resulting in unstable operation.

[0007] An object of the present invention is to suspend a plurality of dust collecting electrode plates, eliminating the drawbacks of the prior art. It is intended to provide a moving electrode for an electrostatic precipitator that prevents elongation due to wear of the endless cable body, maintains the life of the endless cable body, and does not cause unstable operation. Means for solving the problem

[0008] In order to achieve the above object, the moving electrode of the electrostatic precipitator according to the present invention is supported by an endless strip supported rotatably by a drive wheel, and suspended from the endless strip. A plurality of dust collecting electrode plates, and the plurality of dust collecting electrode plates are arranged to move around the discharge electrode in a certain direction and move to a moving electrode of the electrostatic precipitator. It is characterized in that the endless ridge body on which the dust collecting electrode plate is suspended is formed of a flexible endless wire.

[0009] A plurality of engagement step portions are formed at an equal pitch on the outer periphery of the drive wheel, and an engagement block to be pulled by engaging the engagement step portion is arranged at an equal pitch on the endless wire. It is desirable to have an installed configuration. In the moving electrode configured as described above, it is preferable that a suspension member for suspending the dust collecting electrode plate on the endless wire also serves as an engagement block provided on the endless wire. Further, the drive wheel may be a claw wheel, and the endless wire engagement block engaged with the engagement claw of the claw wheel may be a cylindrical body, or the engagement block may be a spherical body. The stepped portion may be formed by a hemispherical concave portion. In addition, if the endless wire is a twisted wire rope, the engagement block may be welded to the endless wire.

The invention's effect

[0010] According to the moving electrode of the electrostatic precipitator according to the present invention, since the endless cable body is a flexible endless cable, elongation due to wear can be prevented and the endless cable body can be used as an endless cable body. Long life can be maintained. In addition, a plurality of engagement step portions are formed on the outer periphery of the drive wheel at an equal pitch, and an engagement block that engages with the engagement step portion is attached to the endless wire at an equal pitch according to the engagement step portion. I made it. According to this configuration, the engaging stepped portion and the engaging block are engaged with each other, whereby the rotational force of the drive wheel is reliably transmitted to the piece member via the engaging block and reliably pulled. For this reason, the dust collecting electrode plate suspended on the endless wire can be moved around in a stable and reliable manner. Further, even if the engagement blocks are worn due to long-term operation, the pitch between the engagement blocks does not change, so that stable operation can be continued. Brief Description of Drawings

FIG. 1 is a perspective view showing an embodiment of a moving electrode of an electrostatic precipitator according to the present invention.

FIG. 2 is a front view showing a main configuration of a moving electrode type electrostatic precipitator.

FIG. 3 is a front view showing a detailed structure of the drive wheel 20 and the endless wire 24. FIG.

FIG. 4 is a view showing an attachment state of the engagement block 38, (1) is a perspective view, and (2) is a cross-sectional view.

[FIG. 5] FIG. 5 is a view showing a mounting state of the suspension member 28, (1) is a perspective view, and (2) is a sectional view.

FIG. 6 is a front view showing an operating state in the vicinity of the driven roller 22.

[FIG. 7] FIG. 7 is a graph comparing the predicted elongation rate of endless striatum.

FIG. 8 is a perspective view showing a schematic structure of a moving electrode according to the prior art.

FIG. 9 is a layout diagram of a lower part of a moving electrode according to the prior art.

FIG. 10 is an explanatory diagram showing the main configuration of an endless chain.

Explanation of symbols

[0012] 18 moving electrode, 20 drive wheel, 22 driven roller, 24 endless wire, 26 dust collecting electrode plate, 28 suspension member, 32 discharge electrode, 34 rotating brush, 36 protrusion, 38 piece member.

BEST MODE FOR CARRYING OUT THE INVENTION

A pair of flexible endless wires 24, 24 are rotatably stretched between a pair of driving wheels 20 arranged at the upper part and a pair of driven rollers 22 arranged at the lower part. The endless wire 24 may be a single wire or a plurality of wire wires, but a wire rope structure with a twist is desirable from the viewpoint of strength. A plurality of dust collecting electrode plates 26, 26,... Are suspended on the pair of endless wires 24, 24 by being locked to the suspension member 28 at intermediate positions in the width direction. The shaft 30 of the drive wheel 20 is rotated by a drive mechanism (not shown), and the rotation of the drive wheel 20 associated with the rotation of the shaft 30 is transmitted to the pair of endless gears 24, 24, thereby forming a loop as a whole. Single dust collection electrode 26, 26 ,... Move around a discharge electrode (not shown).

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 configuration. In the dust collection space, a plurality of discharge electrodes 32 are arranged in parallel at predetermined intervals, and a plurality of moving electrodes 18 are arranged so as to surround every other discharge electrode 32. The dust collecting electrode plate 26 suspended and lowered by the endless wire 24 makes a U-turn at the position of the driven roller 22 and starts to rise. A rotating brush 34 is arranged for each lane of the moving electrode 18 at a position sandwiching the dust collecting electrode plate 26 immediately after the ascent.

A gas to be treated containing high-resistance dust flows in a direction perpendicular to the paper surface of FIG. While the dust collecting plates 26 and 26 move up and down the discharge electrode 32 in the dust collection space above the rotating brush 34, the corona discharge from the discharge electrode 32 charges the dust being processed. And 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 34 is disposed, the dust adhering to the surface of the dust collecting electrode plate 26 is peeled off and removed by the rotating brush 34.

That is, in this type of moving electrode type electrostatic precipitator, while each dust collecting electrode plate 26 moves in the upper dust collecting space where the discharge electrode 32 exists, the surface of each dust collecting electrode plate 26 is moved. Dust is collected, the dust collecting electrode plate 26 descends, makes a U-turn at the position of the driven roller 22, and when it starts to rise, the dust attached to the surface of the dust collecting electrode plate 26 is peeled off by the rotating brush 34. Repeat the removal.

FIG. 3 is a front view showing a detailed structure of the drive wheel 20 and the endless wire 24. This drive wheel 20 is constituted by a claw wheel, and has a claw structure capable of transmitting rotation in one direction. That is, protrusions 36 having eight claw-like engagement step portions 36 a are formed at an equal pitch P on the outer periphery of the drive wheel 20. The endless wire 24 is also connected to the engaging step 36.

0

Engagement block 38 that engages a is attached at an equal pitch P to align with protrusion 36.

0

The 4 is a view showing a state where the engagement block 38 is attached to the endless wire 24. FIG. 4 (1) is a perspective view, and FIG. 4 (2) is a cross-sectional view. The engagement block 38 includes half-cylindrical half members 38a and 38b. The endless wire 24 is sandwiched between these half members 38a and 38b and welded together, and the top and bottom of the half members 38a and 38b are welded to the endless wire 24 as shown in Fig. 4 (2). is there. [0018] FIG. 5 is a view showing a mounting state of the suspension member 28 for suspending the dust collecting electrode plate 26 on the endless wire 24. FIG. 5 (1) is a perspective view, and FIG. 5 (2) is a sectional view. It is. The suspension member 28 includes a semicircular columnar half member 28a and a rectangular parallelepiped half member 28b. The endless wire 24 is sandwiched between these half members 28a and 28b and welded together, and the top and bottom of the half members 28a and 28b are welded to the endless wire 24 as shown in Fig. 5 (2). It is. A surface of the half member 28b opposite to the endless wire 24 side is a mounting surface 28c of the dust collecting electrode plate 26. The dust collecting electrode plate 26 is suspended from the endless wire 24 by welding the intermediate portion in the width direction of the dust collecting electrode plate 26 to the mounting surface 28c. The distance between the suspension member 28 and the front and rear engaging blocks 38 is the pitch P.

The suspension member 28 also serves as the engagement block 38.

In the state shown in FIG. 3, when the drive wheel 20 rotates counterclockwise as indicated by the arrow Y, the engagement step portion 36a located on the upper surface of the projection 36 formed on the drive wheel 20 and the engagement block 3 8 The lower surface of the surface rubs. For this reason, the rotational force of the drive wheel 20 is reliably transmitted to the engagement block 38 via the projection 36 having the engagement step 36a, and the endless wire 24 with the dust collecting electrode plate 26 suspended is reliably 1 pitch P at a time. To be raised.

0

[0020] A conductive material is used for the endless wire 24, and the current from each dust collecting electrode plate 26 is also grounded via the drive wheel 20, the driven roller 22 and the like! /, The Therefore, dust adheres to the endless wire 24 in the same manner as the dust collecting electrode plate 26. However, when the endless wire 24 passes through the drive wheel 20 while the force is applied, the engagement block 38 and the suspension member 28 are interposed between the endless wire 24 and the drive wheel 20 as shown in FIG. Therefore, endless wire 24 and drive wheel 20 are almost in contact with each other. Even when the endless wire 24 passes through the driven roller 22, the engagement block 38 and the suspension member 28 are interposed between the endless wire 24 and the driven roller 22 as shown in FIG. Little contact with roller 22. Therefore, there is a low possibility that the endless wire 24 is quickly worn out by dust adhering to the endless wire 24.

[0021] FIG. 7 is a graph comparing the expected elongation rate of endless cords. In the figure, curve a shows the case of endless wire 24 of the present embodiment, and curve b shows the case of an endless chain according to the prior art. With the endless wire 24 of the curve a, there is a tendency that the wire tends to stretch slightly in the initial stage of operation. On the other hand, in the endless chain according to the prior art of curve b, Elongation progresses almost in proportion to the rolling time, and when the operation time is 100,000 hours, the elongation reaches 2%.

[0022] Note that the engagement block 38 and the suspension member 28 are made of carbon steel-based conductive material from the viewpoint of strength and economy, and dust adheres to these members. When the endless wire 24 passes through the driving wheel 20 and the driven roller 22, these members come into contact with the driving wheel 20 and the driven roller 22, and the adhering dust wears the engagement block 38 and the suspension member 28. Speed up. However, even if the engagement block 38 and the suspension member 28 are worn to some extent, the pitch P between the engagement blocks 38 shown in FIG. 3 does not change, so that stable operation can be continued.

0

[0023] As described above, according to the moving electrode of the electrostatic precipitator of this embodiment, since the endless cord body is made of the flexible endless wire 24, elongation due to wear can be prevented, and the endless cord can be prevented. Long life as a body can be maintained. Further, a protrusion 36 having a plurality of engagement step portions 36a is formed on the outer periphery of the drive wheel 20 at an equal pitch, and an engagement block 38 that engages with the engagement step portion 36a is formed on the endless wire 24. Installed at equal pitch according to 36. According to this configuration, the protrusion 36 having the engagement step 36a and the engagement block 38 are engaged with each other, so that the rotational force of the drive wheel 20 is reliably applied to the engagement block 38 via the engagement step 36a. Is transmitted to. For this reason, the dust collecting electrode plate 26 suspended from the endless wire 24 can be moved around in a stable and reliable manner. In addition, even if the engagement block 38 is worn due to long-term operation, the pitch P between the engagement blocks 38 does not change, so that stable operation can be continued.

0

wear.

[0024] In the above embodiment, a case has been described in which the number of engagement step portions formed on the drive wheel is eight. However, the number of engagement step portions formed on the drive wheel according to the present invention is not particularly limited as long as it is plural. In practice, it is desirable to select the protrusions with the engaging step within the range of 6-16. Further, the means for fixing the frame member or the suspension member to the endless wire can be replaced with welding and tightened with bolts.

[0025] Furthermore, in the above-described embodiment, the drive wheel is constituted by a ratchet wheel. However, an engaging step portion having a uniform hemispherical concave force is formed on the outer peripheral surface of the wheel, while the endless wheel is endless. It can also be set as the structure which attaches a spherical block at equal pitch to the wire side.

Claims

The scope of the claims

[1] It has an endless strip rotatably supported by a drive wheel, and a plurality of dust collecting plates suspended on the endless strip, and the plurality of dust collecting plates are released. A moving electrode of an electrostatic precipitator that moves around the electrode in a fixed direction! The moving electrode of the electrostatic precipitator is characterized in that the endless cable body for suspending the dust collecting electrode plate is formed of a flexible endless wire.

[2] A plurality of engagement step portions are formed at an equal pitch on the outer periphery of the drive wheel, and an engagement block to be pulled by being engaged with the engagement step portion is arranged at an equal pitch on the endless wire. The moving electrode of the electrostatic precipitator according to claim 1, wherein the moving electrode is attached.

[3] The movement of the electrostatic precipitator according to claim 2, wherein a suspension member for suspending the dust collection electrode plate on the endless wire also serves as an engagement block provided on the endless wire. electrode.

4. The electrostatic precipitator according to claim 1, wherein the driving wheel is a claw wheel, and an engagement block of an endless wire engaged with an engagement claw of the claw wheel is a cylindrical body. Moving electrode.

5. The moving electrode for an electrostatic precipitator according to claim 1, wherein the engaging block is a sphere, and the engaging step portion is formed by a hemispherical concave portion.

6. The moving electrode for an electric dust collector according to claim 1, wherein the endless wire is a twisted wire rope.

7. The moving electrode of the electrostatic precipitator according to claim 1, wherein the engagement block is welded to an endless wire.