1. A dust collection plate of a moving electrode-type electrostatic precipitator that includes an endless chain rotatably supported by upper and lower sprocket wheels and a plurality of dust collection plates which are moved together with the endless chain around a discharge electrode in a predetermined direction, wherein, in the dust collection plate, two rectangular steel plates are welded at upper and lower end portions by spot welding, a square frame inserted into an intermediate portion between the two steel plates and the two steel plates are welded by spot welding, a side sealing plate that fills a substantially triangle gap formed in a side surface portion of the dust collection plate, and joint fittings for attaching the endless chain to both end portions of the frame are provided.

2. A method of manufacturing a dust collection plate of a moving electrode-type electrostatic precipitator that includes an endless chain rotatably supported by upper and lower sprocket wheels and a plurality of dust collection plates which are moved together with the endless chain around a discharge electrode in a predetermined direction, wherein the dust collection plate has a structure where two rectangular steel plates are placed on each other is placed on a flat surface, after upper and lower end portions are welded by spot welding, a space is formed between the two steel plates, after a square frame is inserted, in a longitudinal direction, into the space, the two steel plates and the frame are welded by spot welding, and after a side sealing plate that fills a substantially triangle gap formed in a side surface portion of the dust collection plate is provided, joint fittings for attaching the dust collection plate to the endless chain are joined to both end portions of the frame.

TECHNICAL FIELD

[0001] The present invention relates to the dust collection plate of a moving electrode-type electrostatic precipitator, and more particularly to the dust collection plate of a moving electrode-type electrostatic precipitator which is configured such that a plurality of dust collection plates coupled to an endless chain are moved around a discharge electrode.

BACKGROUND ART

[0002] As shown in Figs. 6 and 7, a moving electrode-type electrostatic precipitator 1 has a structure in which, while dust collection plates 10 constituting a duct collection electrode are moved around a discharge electrode 5 in a vertical direction, dust is charged by a high voltage applied between both electrodes, the dust is collected in the duct collection electrode and the dust is brushed down with a brush 6 provided in a lower portion of the duct collection electrode. As compared with a hammering method performed in a general fixed electrode-type electrostatic precipitator, it is unlikely that dust fails to be separated and is dispersed again over backward flow, and thus it is possible to achieve a high dust collection function. However, since the dust collection plates need to be rugged in structure because of the provision of a drive device for moving the dust collection plates 10 and the following reason, a simpler and inexpensive structure is required.

[0003] In the structure of the duct collection electrode, a plurality of dust collection plates 10 long in a horizontal direction are aligned in a vertical direction, are suspended with two endless chains 14 provided on both ends (left and right ends) in the horizontal direction and are moved around in the shape of a caterpillar. On its upper and lower ends, sprocket wheels 3, 18, 4 and 20 are provided, and the dust collection plates 10 are inversely operated along the circumference of the sprocket wheels. During the inversion, the dust collection plates 10 are brought into a horizontal position, and are bent and deformed by the weight of the dust collection plates 10 themselves and the weight of the dust adhered thereto.

[0004] Hence, in patent document 1, a dust collection plate that is reinforced in the shape of a frame with a hollow box cross section or a hollow strength member is adopted so that the dust collection plates 10 are prevented from being elastically bent and deformed and buckled. However, the production of this configuration disadvantageously requires time and efforts and increases the cost of the device.

Related Art Document Patent Document

[0005] Patent document 1: Japanese Unexamined Patent Application Publication No. HI0-230187

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

[0006] For example, one way to inexpensively produce the dust collection plate 10 having the hollow box structure described above is to reduce the thickness of a steel plate. Figs. 1A and 1(B) are respectively diagrams showing parts (contact parts between the frame and the steel plate) of the dust collection plates having a steel plate thickness of 0.8 mm and a steel plate thickness of 0.4 mm. When the thickness of the steel plate 11 is reduced, in its production, the steel plate 11 is bent or wrinkled even in a part where the frame 12 and the steel plate 11 are welded by the effect of bending in a place other than the frame 12 which is not supported by its weight, with the result that, as shown in Fig. IB, a gap 15 is disadvantageously produced between the frame 12 and the steel plate 11. When, as described above, the gap 15 is present in the dust collection plate 10, dust enters the dust collection plate 10 through the gap 15 and is stored within the dust collection plate 10, with the result that it is likely that the dust collection plate 10 is increased in weight and is deformed.

[0007] The increase in the weight of the dust collection plate 10 leads to an increase in the drive power of the duct collection electrode and an increase in the wear of sliding components such as the sprocket wheels 3, 18, 4 and 20 and the endless chains 14, and the deformation of the dust collection plate 10 induces the production of a spark caused by variations in the separation distance between the discharge electrode 5 and the duct collection electrode and reduces the dust collection function.

[0008] . Hence, an object of the present invention is to provide the structure of a dust collection plate that has even a thin steel plate and is prevented from being bent and a method of manufacturing it.

Means for Solving the Problem

[0009] To achieve the above object, in the structure of a dust collection plate 10 of a moving electrode-type electrostatic precipitator according to the present invention, the dust collection plate 10 has a structure where two rectangular steel plates 11 are placed on each other is placed on a flat surface, after upper and lower end portions are welded by spot welding, a space is formed between the two steel plates 11, after a square frame 12 is inserted, in a longitudinal direction, into the space, the two steel plates 11 and the frame 12 are welded by spot welding, and joint fittings 16 for attaching the dust collection plate 10 to the endless chain 14 are provided.

Effects of the Invention

[0010] In the structure of the dust collection plate of the moving electrode-type electrostatic precipitator having the feature described above, even the thin steel plates can be joined without being bent, with the result that it is possible to manufacture the light and inexpensive dust collection plate 10 without any gap being produced in the place where the two steel plates 11 are joined.

BRIEF DESCRIPTION OF DRAWINGS

[0011]

[Fig. 1A] A schematic diagram showing a problem in a dust collection plate formed with thin steel plates;

[Fig. IB] A schematic diagram showing a problem in a dust collection plate formed with thin steel plates;

[Fig. 2] A bird's eye view showing a dust collection plate of the present invention;

[Fig. 3] A side view showing the dust collection plate of the present invention;

[Fig. 4A] A schematic diagram showing the procedure of manufacturing the dust collection plate of the present invention;

[Fig. 4B] A schematic diagram showing the procedure of manufacturing the dust collection plate of the present invention;

[Fig. 4C] A schematic diagram showing the procedure of manufacturing the dust collection plate of the present invention;

[Fig. 5 A] A schematic diagram of an enlarged joint portion of the dust collection plate of the present invention;

[Fig. 5B] A schematic diagram of an enlarged joint portion of the dust collection plate of the present invention;

[Fig. 6] A conceptual diagram showing the internal structure of a moving electrode-type electrostatic precipitator; and

[Fig. 7] A conceptual diagram showing the details of the internal structure of the moving electrode-type electrostatic precipitator.

BEST MODE FOR CARRYING OUT THE INVENTION

[0012] Fig. 2 is a bird's eye view showing the outline of a dust collection plate 10 according to the present invention, and Fig. 3 is a side view showing the dust collection plate 10. In the structure of the dust collection plate 10, two steel plates 11 long in a horizontal direction are joined at their upper and lower end portions by spot welding 13, a frame 12 is inserted, in the longitudinal direction, into a gap formed in an intermediate portion of the two steel plates 11, the steel plates 11 and the frame 12 are joined by spot welding, side surface sealing plates 17 are joined by spot welding to the steel plates 11 in the substantially triangular gaps of both side surfaces of the dust collection plate 10 so as to fill the gaps and furthermore joint fittings 16 for joining to endless chains (not shown) are welded to both ends of the frame 12.

[0013] The dust collection plate 10 is configured as described above, as compared with the conventional configuration where the dust collection plate is reinforced in the shape of a frame with a strength member, it is possible to significantly reduce the amount of frame members and the weight of the steel plates to achieve a low cost and to prevent the following problem: dust is deposited on the frame in the upper portion of the dust collection plate, the deposited dust is scattered when the dust collection plate is reversed and is escaped out of a precipitator and thus a dust collection function is reduced.

[0014] The upper and lower end portions of the steel plates 11 are joined and are thereby increased in rigidity, and thus it is possible to maintain a mechanical strength to a degree comparable to the case where the frame is used, even in comparison with the case. Furthermore, as shown in Fig. 7, dust adhered to the dust collection plate 10 is treated by fitting the dust collection plate 10 between two rotating brushes, and since the upper and lower end portions of the dust collection plate 10 are formed to have an acute angle (see Fig. 3), it is possible to reduce a resistance when the dust collection plate 10 is fitted between the brushes 6 and to also prevent the wear and the broken bristles of the brush 6.

[0015] A method of manufacturing the dust collection plate 10 discussed above will be described in more detail. As shown in Fig. 4A, the surface of the thin steel plate 11 is placed on a flat plate stage 21 in the shape of a flat surface, and while the steel plate 11 and the flat plate stage 21 are displaced from each other to expose a welding portion, welding is performed with a spot welding machine 24.

[0016] Then, as shown in Fig. 4B, the intermediate portion of the two steel plates 11 that are spot-welded is widened, the frame 12 is inserted into the gap and the frame 12 and the steel plates 11 are welded by spot welding. Here, in the upper and lower end portions of the steel plates 11, from the state where the two steel plates are placed on each other as shown in Fig. 5A, as shown in Fig. 5B, a force is applied in a direction in which the upper and lower end portions (in the figure, the left end) of the steel plates 11 are closed, and thus the production of a gap in the joint portion of the steel plates 11 is prevented.

[0017] Thereafter, the side surface sealing plates 17 are inserted into the substantially triangular gaps formed in both side surfaces of the dust collection plate 10, and the joint surfaces of the side surface sealing plates 17 and the steel plates 11 are welded by spot welding.

[0018] Then, as shown in Fig. 4C, the endless chains and the joint fittings 16 are welded to both end surfaces of the frame 12.

[0019] Although in the above description, the joint fittings 16 having bolt holes for securing the endless chains 14 (Fig. 7) with bolts are shown, the present invention is not limited to this configuration, and the joint fittings 16 may be shaped to be directly welded to the endless chains 14 with no holes. Although Figs. 4B and 4C show the state where the dust collection plate 10 stands upright, as shown in Fig. 4A, the operation described above may be performed in the state (horizontal state) where the dust collection plate 10 is placed on the flat plate stage 21.

We Claim:

1. A dust collection plate of a moving electrode-type electrostatic precipitator that includes an endless chain rotatably supported by upper and lower sprocket wheels and a plurality of dust collection plates which are moved together with the endless chain around a discharge electrode in a predetermined direction, wherein, in the dust collection plate, two rectangular steel plates are welded at upper and lower end portions by spot welding, a square frame inserted into an intermediate portion between the two steel plates and the two steel plates are welded by spot welding, a side sealing plate that fills a substantially triangle gap formed in a side surface portion of the dust collection plate, and joint fittings for attaching the endless chain to both end portions of the frame are provided.

2. A method of manufacturing a dust collection plate of a moving electrode-type electrostatic precipitator that includes an endless chain rotatably supported by upper and lower sprocket wheels and a plurality of dust collection plates which are moved together with the endless chain around a discharge electrode in a predetermined direction, wherein the dust collection plate has a structure where two rectangular steel plates are placed on each other is placed on a flat surface, after upper and lower end portions are welded by spot welding, a space is formed between the two steel plates, after a square frame is inserted, in a longitudinal direction, into the space, the two steel plates and the frame are welded by spot welding, and after a side sealing plate that fills a substantially triangle gap formed in a side surface portion of the dust collection plate is provided, joint fittings for attaching the dust collection plate to the endless chain are joined to both end portions of the frame.