DESCRIPTION
MOVING ELECTRODE OF ELECTROSTATIC PRECIPITATOR
Technical Field [0001]
The present invention relates to a moving electrode of an electrostatic precipitator, and more particularly to a moving electrode of an electrostatic precipitator arranged such that a plurality of dust collecting electrode plates coupled with endless rope members are caused to circularly move around discharge electrodes. Background Art [0002]
An electrode moving type electrostatic precipitator disclosed in Patent Document 1 may be used to remove dusts from exhaust gases of a boiler of a thermal power station and from exhaust gases of various types of furnaces. Fig. 6 is a perspective view showing a schematic structure of moving electrodes used in this kind of the electrode moving type electrostatic precipitator. A pair of endless chains 3, 3 are rotatably stretched between a pair of driving sprocket wheels 1 disposed in upper portions and a pair of driven rollers 2 disposed in a lower portion. A plurality of dust collecting electrode plates 4, 4, ... are coupled with the pair of endless chains 3, 3 therebetween in such a manner that the central portions of the side edges thereof are fixed to coupling
portions 5. A shaft 6 of the driving sprocket wheels 1 is rotated by a not shown drive mechanism, the rotation of the shaft 6 is transmitted to the pair of endless chains 3, 3 meshed with the driving sprocket wheels 1, thereby the plurality of dust collecting electrode plates 4, 4, ... which constitute a loop in their entirety circularly move around not shown discharge electrodes. [0003]
Fig. 7 is a layout of a lower portion of moving electrodes 10, wherein the dust collecting electrode plates 4, which move downward while being suspended by the endless chains 3, U-turn at the positions of the driven rollers 2 and change to an upward movement. Rotary brushes 7 are disposed to respective lanes of the moving electrodes 10 at the positions where the rotary brushes 7 sandwich the dust collecting electrode plates 4 just after they move upward. The discharge electrodes 8 are disposed above the rotary brushes 7 . While the dust collecting electrode plates 4, 4 move beside the discharge electrodes 8 in an up and down direction, the dusts in exhaust gases are charged by the corona discharge from the discharge electrodes 8 and captured on the surfaces of the respective dust collecting electrode plates 4. When the respective dust collecting electrode plates 4 pass through the positions where the rotary brushes 7 are disposed, the dusts deposited on the surfaces of the dust collecting electrode plates 4 are exfoliated and removed by the rotary brushes 7. [0004]
That is, in this kind of the electrode moving type electrostatic precipitator, dusts are captured on the surfaces of the respective dust collecting electrode plates 4 while they move in an upper dust collection space in which the discharge electrodes 8 exist, and the dusts deposited on the surfaces of the dust collecting electrode plates 4 are exfoliated and removed by the rotary brushes 7 when the dust collecting electrode plates 4 move downward, U-turns at the positions of the driven rollers 2, and moves upward, and these operations are performed repeatedly. According to the above arrangement, each time the dust collecting electrode plates 4 pass through the rotary brushes 7, since the dusts deposited on the surfaces of the dust collecting electrode plates 4 are securely removed, the degree of cleanness of the surfaces of the dust collecting electrode plates 4 can be restored. Therefore, the thickness of the layer of the dusts captured by and deposited on the surfaces of the dust collecting electrode plates 4 can be kept thin at all times. [0005]
The dust collecting performance of the electrostatic precipitator is greatly affected by the electric resistivity of captured dusts. In particular, when the thickness of a dust layer deposited on the surfaces of the dust collecting electrode plates becomes larger than a predetermined value at the time the electric resistivity of the dusts has a high value of 1012 Ω or more, since a back corona phenomenon occurs, the dust collecting performance is abruptly deteriorated. Since the
electrode moving type electrostatic precipitator can keep the thickness of the layer of the dusts captured by and deposited on the surfaces of the dust collecting electrode plates 4 thin at all times as described above, the back corona phenomenon is unlike to occur . Accordingly, this kind of the electrode moving type electrostatic precipitator is mainly used for exhaust gases containing high resistant dusts.
Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2001-246284 Disclosure of the Invention Problems to be Solved by the Invention [0006]
However, in the moving electrodes 10 arranged as described above, since the dust collecting electrode plates 4 are fixed to the endless chains 3 at the central portions of the side edges thereof through the coupling portions 5, the coupling portions 5 must have a strong and large-scale structure to withstand the load of the dust collecting electrode plates 4. [0007]
Further, in the electrode moving type electrostatic precipitator arranged as described above, the moving electrodes are disposed such that the dust collecting electrode plates 4 move while keeping the same distance to the discharge electrodes 8 which are disposed in parallel at a pitch D as shown in Fig. 8. Accordingly, the outside diameters of the driving sprocket wheels 1 and the driven rollers 2 that constitute the moving
electrodes 10 and the separation distance between the moving electrodes 10 are also set according to the pitch D. [0008]
In the layout as described above, when the dust collecting electrode plates 4 U-turn at the positions of the driving sprocket wheels 1 and the driven roller 2, both the ends of the dust collecting electrode plates 4 draw moving loci X shown by two-dot-and-dash-lines of Fig. 8. When the moving loci X of adjacent lanes intersect, there is a possibility that adjacent dust collecting electrode plates 4 collide with each other. Thus, the width W of the dust collecting electrode plates 4 is restricted and must be ordinarily suppressed to about v3 (1.73) D from the geometrical relation thereof. Accordingly, since the dimension of one dust collecting electrode plate 4 is reduced, the number of components is increased for that, by which is a cost is increased. [0009]
An object of the present invention is to improve the drawback of the related art and to provide moving electrodes of an electrostatic precipitator which can reduce the number of components by increasing the width of one dust collecting electrode plate as well as makes coupling portions that couple dust collecting electrode plates with endless rope members compact.
Means for Solving the Problems [0010]
To achieve the above object, in a moving electrode of an
electrostatic precipitator according to the present invention including a pair of upper rollers disposed to an upper portion, a pair of lower rollers disposed to a lower portion, a pair of endless rope members stretched to connect the respective upper rollers to the respective lower rollers, and a plurality of dust collecting electrode plates coupled with the pair of endless rope members and arranged to cause the plurality of dust collecting electrode plates to circularly move around discharge electrodes, the moving electrode is characterized in that the respective dust collecting electrode plates are rotatably couple with the endless rope members at positions higher than the centers of gravity thereof as well as the respective upper rollers are supported by cantilever shafts from the outside of the moving region of the dust collecting electrode plates . Note that the endless rope member is a wide concept including a continuous rope such as a wire rope formed in a loop shape by coupling the ends thereof in addition of an endless chain formed in a loop shape by coupling the ends thereof. [0011]
The moving electrode of the electrostatic precipitator according to the present invention is characterized by including an inclination sensor for detecting the inclinations of the respective dust collecting electrode plates and a control means for controlling the numbers of rotations of the respective cantilever shafts of the upper rollers in response to a detection performed by the inclination sensor.
Further, the moving electrode of the electrostatic
precipitator according to the present invention is characterized that drive mechanisms are provided so as to be coupled with the respective cantilever shafts of the upper rollers to rotate the respective cantilever shafts in the same direction at the same number of rotations. [0012]
The moving electrode of the electrostatic precipitator according to the present invention is characterized that a rotary shaft is disposed adjacent to the cantilever shafts, and the rotation of the rotary shaft is transmitted to the cantilever shafts through a transmission mechanism.
The moving electrode of the electrostatic precipitator according to the present invention is characterized that the lower rollers are coupled with each other through a single drive shaft and a rotation drive source is connected to the drive shaft.
Effects of the Invention [0013]
According to the moving electrode of the present invention, the plurality of dust collecting electrode plates are rotatably coupled with the endless rope member at the positions higher than the centers of gravity thereof. Further, the upper rollers are supported by the cantilever shafts from the outside of the moving region of the dust collecting electrode plates . Accordingly, the respective dust collecting electrode plates stably move at all times keeping a hanging state in a vertical direction due to the deadweight thereof.
[0014]
Accordingly, when the dust collecting electrode plates of adjacent lanes pass through the upper rollers and the lower rollers, there is not a possibility at all the dust collecting electrode plates collide with each other. Further, since the upper rollers are supported by the cantilever shafts from the outside of the moving region of the dust collecting electrode plates, when the respective hanging dust collecting electrode plates pass through the upper rollers, the cantilever shafts and the like do not interfere with the dust collecting electrode plates. Accordingly, the number of components can be reduced by increasing the width W of the dust collecting electrode plates. Since the coupling portions need not strongly fix the dust collecting electrode plates to the endless rope member and it is sufficient for them to simply couple the dust collecting electrode plates rotatably with the endless rope members, the coupling portions can be made to a compact structure. [0015]
When the inclination sensor for detecting the inclination of the respective dust collecting electrode plates and the control means for controlling the number of rotations of the respective cantilever shafts of the upper rollers in response to the detection performed by the inclination sensor are provided, there can be avoided a trouble in that the moving speeds of the endless rope members are made different from each other and thus the respective dust collecting electrode plates are inclined.
[0016]
When the drive mechanism is provided to rotate the respective cantilever shafts of the upper rollers in the same direction at the same number of rotations by coupling the cantilever shafts with each other, since the moving speeds of the pair of endless rope members can be caused to agree with each other, there can be avoided a trouble in that the respective dust collecting electrode plates are inclined. [0017]
When the rotary shaft is disposed adjacent to the cantilever shafts and the rotation of the rotary shaft is transmitted to the cantilever shafts through the transmission mechanism, the moving speeds of the pair of endless chains 24 can be caused to agree with each other. As a result, a trouble in that the respective dust collecting electrode plates 26 which are coupled with the endless chains 24 are greatly inclined and the moving electrode 18 becomes inoperable can be avoided.
Further, when the lower rollers are coupled with each other through the single drive shaft and the rotation drive source is connected to the drive shaft, the driving wheel can be directly coupled with each other by the rotary shaft, thereby a drive system can be simplified. Brief description of the Drawings [0018]
Fig. 1 is a schematic perspective view showing a first embodiment of a moving electrode according to the present invention.
Fig. 2 is an elevation view showing a main arrangement of an electrode moving type electrostatic precipitator having the moving electrode according to the present invention.
Fig. 3 is a schematic side elevational view showing a second embodiment of the moving electrode according to the present invention.
Fig. 4 is a schematic side elevational view showing a third embodiment of the moving electrode according to the present invention.
Fig. 5 is a schematic side elevational view showing a fourth embodiment of the moving electrode according to the present invention.
Fig. 6 is a perspective view showing an outline structure of a moving electrode according to a related art.
Fig. 7 is a layout of the lower portion of the moving electrode according to the related art.
Fig. 8 is a schematic side elevational view explaining a problem of the moving electrode according to the related art. Explanation of Reference Numerals [0019]
18 ... moving electrode, 20, 20A ... driving wheel, 22, 22A ... driven roller, 24 ... endless chain, 26 ... dust collecting electrode plate, 28 ... coupling portion, 30 ... cantilever shaft, 32 ... drive mechanism, 34 ... discharge electrode, 36 ... rotary brush, 38 ... inclination sensor, 40 ... controller, 42 ... number of rotation adjustment means, 44 ... cantilever shaft, 46 ... first sprocket, 48 ... second sprocket, 50 ... rotary shaft, 52 ... drive mechanism,
54 ... sprocket chain, 56 ... rotary shaft, 58 ... drive mechanism,
60 ... cantilever shaft.
Best Mode for Carrying Out the Invention
[0020]
Fig. 1 is a schematic perspective view showing a first embodiment of a moving electrode of an 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 disposed in an upper portion and a pair of driven rollers 22, 22 disposed in a lower portion. A plurality of rectangular dust collecting electrode plates 26, 26, ... are coupled with the pair of endless chains 24, 24 through coupling portions 28 at the upper end positions thereof so as to be freely rotated about a horizontal axes. Note that, in Fig. 1, illustration of some of the dust collecting electrode plates 26 are omitted for the purpose of convenience of explanation. [0021]
The respective driving wheels 20, 20 are supported by cantilever shafts 30, 30, respectively from the outside of the moving region of the dust collecting electrode plates 26, 26 and are driven in rotation by drive mechanisms 32, 32, respectively. The rotation of the driving wheels 20, 20 is transmitted to the pair of endless chains 24, 24, thereby the plurality of the dust collecting electrode plates 26, 26, ... which form a loop in their entirety circularly move around not shown discharge electrodes.
[0022]
Fig. 2 is an elevation view showing a main arrangement of the electrode moving type electrostatic precipitator having the moving electrode 18 arranged as described above. The plurality of discharge electrodes 34, 34, ... are disposed in parallel at predetermined intervals in a dust collection space, and a plurality of the moving electrode 18 are disposed so as to surround these discharge electrodes 34 alternately. The dust collecting electrode plates 26, which are coupled with the endless chains 24 and move downward, changes to an upward movement at the positions of the driven rollers 22 while keeping a vertically hanging state due to the deadweight thereof even at the positions. Rotary brushes 36 are disposed to respective lanes of the moving electrodes 18 at the positions where the rotary brushes 36 sandwich the dust collecting electrode plates 26 just after they move upward. [0023]
Gases to be processed that contain high resistant dusts flow in a vertical direction with respect to a sheet surface. While the dust collecting electrode plates 26, 26 move in an up and down direction beside the discharge electrodes 34 in the dust collection space above the rotary brushes 36, the dusts in the gases to be processed are charged by corona discharge from the discharge electrodes 34 and captured on the surfaces of the respective dust collecting electrode plates 26. When the respective dust collecting electrode plates 26 pass through the positions at which the rotary brushes 36 are disposed, the
dusts deposited on the surfaces of the dust collecting electrode plates 26 are exfoliated and removed by the rotary brushes 36. [0024]
More specifically, in this kind of the electrode moving type electrostatic precipitator, dusts are captured on the surfaces of the respective dust collecting electrode plates 26 while they move in the upper dust collection space, in which the discharge electrodes 34 exist, keeping a vertical state at all times, and the dusts deposited on the surfaces of them are exfoliated and removed by the rotary brushes 36 just after the dust collecting electrode plates 26 move downward and change to the upward movement from the positions of the driven rollers 22, and these operation are performed repeatedly. When the dust collecting electrode plates 26 move upward and pass through the driving wheels 20, they change to a downward movement keeping the hanging state thereof in the vertical direction due to the deadweight thereof. [0025]
As described above, according to the moving electrode 18 of the embodiment, the plurality of the dust collecting electrode plates 26, 26, ... are rotatably coupled with the endless chains 24, 24 as endless rope members at the upper end positions thereof through the coupling portions 28. Further, the driving wheels 20 as upper rollers are supported by the cantilever shafts 30 from the outside of the moving region of the dust collecting electrode plates 26. Accordingly, the respective dust collecting electrode plates 26 stably move
keeping the hanging state in the vertical direction at all times due to the deadweight thereof. [0026]
Therefore, there is not a possibility at all that the dust collecting electrode plates 26 collide with each other even when the dust collecting electrode plates 26 of adjacent lanes pass through the driving wheels 20 and the driven rollers 22. Further, since the driving wheels 20 are supported by the cantilever shafts 30 from the outside of the moving region of the dust collecting electrode plates 26, when the respective hanging dust collecting electrode plates 26 pass through the driving wheels 20, the cantilever shafts 30 and the like do not interfere with the dust collecting electrode plates 26. Accordingly, the number of components can be reduced by increasing the width W of the dust collecting electrode plates 26. Further, since the coupling portions 28 need not strongly fix the dust collecting electrode plates 26 to the endless chains 24, 24 and it is sufficient for them to simply couple the dust collecting electrode plates 26 rotatably with the endless chains 24, 24, the coupling portions 28 can be made to a compact structure. [0027]
Note that, in the moving electrode 18 arranged as described above, the pair of driving wheels 20 are driven in rotation by the individual drive mechanisms 32, respectively. Accordingly, there is a possibility that the rotation speeds of the pair of driving wheels 20 do not agree with each other
by slippage of shaft of motors that constitute the drive mechanism 32, and the like. When the rotation speeds of the pair of driving wheels 20 do not agree with each other, since the moving speeds of the pair of endless chains 24 driven by the rotation of the respective driving wheels 20 are made different from each other, the respective dust collecting electrode plates 26 coupled with the endless chains 24 are greatly inclined, from which the moving electrode 18 may become inoperable.
[0028]
Fig. 3 is an explanatory view showing an arrangement of a second embodiment for avoiding the above trouble. The moving electrode 18 has an inclination sensor 38 for detecting inclination of the dust collecting electrode plates 26 while they move, and a result of detection of the inclination sensor 38 is transmitted to a controller 40. The controller 40 controls at least one of number of rotation adjustment means
(for example, inverter) 42 provided with drive mechanisms 32, 32 to eliminate the inclination of the dust collecting electrode plates 26.
[0029]
Fig. 4 is a schematic side elevational view showing a third embodiment of the moving electrode of the electrostatic precipitator according to the present invention. In Fig. 4, since the components denoted by the same reference numerals as those of Fig. 1 have the same arrangement and the same function as the components explained in the first embodiment, the
explanation thereof is omitted. Cantilever shafts 44 according to the embodiment have first sprockets 4 6 in addition to the driving wheels 20. A rotary shaft 50 having a pair of second sprockets 48 is disposed above the driving wheels 20, and the rotary shaft 50 is driven in rotation by a drive mechanism 52. A mechanism for transmitting the rotation of the rotary shaft 50 is provided. That is, the respective first sprockets 46 are coupled with the respective second sprockets 48 by sprocket chains 54. Accordingly, since the driving force of the drive mechanism 52 is transmitted in a sequence of the rotary shaft 50, the second sprockets 48, the first sprockets 46, the cantilever shafts 44, and the driving wheels 20, the pair of driving wheels 20, 20 are rotated in the same direction at the same number of rotations . Accordingly, since the moving speeds of the pair of endless chains 24 can be caused to agree with each other, the countermeasure for avoiding a trouble as shown in Fig. 3 need not be employed. [0030]
Fig. 5 is a schematic side elevational view showing a fourth embodiment of the moving electrode of the electrostatic precipitator according to the present invention. In Fig. 5, since the components denoted by the same reference numerals as those of Fig. 1 have the same arrangement and the same function as the components explained in the first embodiment, the explanation thereof is omitted. In the embodiment, a pair of driven rollers 22A, 22A as lower rollers are coupled with each other by a single rotary drive shaft as well as a rotation drive
source is connected to the rotary drive shaft. That is, the pair of driving wheels 20A, 20A are disposed to a lower portion contrary to the first embodiment, and a pair of driven rollers 22A, 22A are disposed to a upper portion. The pair of driving wheels 20A, 20A are coupled with a rotary shaft 56, and the rotary shaft 56 is driven in rotation by a drive mechanism 58. [0031]
A pair of driven rollers 22A, 22A are supported by cantilever shafts 60, 60 from the outside of the moving region of the dust collecting electrode plates 26, respectively. The plurality of the dust collecting electrode plates 26, 26, ... are rotatably coupled with the pair of endless chains 24, 24 through the coupling portions 28 at intermediate positions higher than the centers of gravity thereof. [0032]
According to the moving electrode of the fourth embodiment, the driving wheels 20A, 20A are disposed to the lower portion. Accordingly, since the driving wheels 20A, 20A can be directly coupled with each other by the rotary shaft 56, a driving system can be simplified. Further, since the coupling portions 28 of the dust collecting electrode plates 26 are disposed at the positions that are located above the intermediate positions of the dust collecting electrode plates 2 6 and below the upper ends thereof, when the dust collecting electrode plates 26 have the same width W, the lower end height of the dust collecting electrode plates 26 can be increased when they pass through the driving wheels 20A and the driven roller
22A, which is useful to improve the space efficiency of the moving electrodes.

CLAIMS
1. A moving electrode of an electrostatic precipitator comprising a pair of upper rollers disposed to an upper portion, a pair of lower rollers disposed to a lower portion, a pair of endless rope members stretched to connect the respective upper rollers to the respective lower rollers, and a plurality of dust collecting electrode plates coupled with the pair of endless rope members and arranged to cause the plurality of dust collecting electrode plates to circularly move around discharge electrodes, characterized in that the respective dust collecting electrode plates are rotatably couple with the endless rope members at positions higher than the centers of gravity thereof as well as the respective upper rollers are supported by cantilever shafts from the outside of the moving region of the dust collecting electrode plates.
2. The moving electrode of the electrostatic precipitator according to claim 1, characterized by comprising an inclination sensor for detecting the inclinations of the respective dust collecting electrode plates and a control means for controlling the numbers of rotations of the respective cantilever shafts of the upper rollers in response to a detection performed by the inclination sensor.
3. The moving electrode of the electrostatic precipitator according to claim 1, characterized in that drive mechanisms are provided so as to be coupled with the respective cantilever shafts of the upper rollers to rotate the respective cantilever shafts in the same direction at the same number of
rotations.
4. The moving electrode of the electrostatic precipitator according to claim 1, characterized in that a rotary shaft is disposed adjacent to the cantilever shafts, and the rotation of the rotary shaft is transmitted to the cantilever shafts through a transmission mechanism.
5. The moving electrode of the electrostatic precipitator according to claim 1, characterized in that the lower rollers are coupled with each other through a single drive shaft and a rotation drive source is connected to the drive shaft.