WO2007063666A1

WO2007063666A1 - Dust collecting electrode plate of electrical dust collector

Info

Publication number: WO2007063666A1
Application number: PCT/JP2006/321663
Authority: WO
Inventors: Keigo Orita; Yoshihiko Mochizuki; Takeo Arimitsu
Original assignee: Hitachi Plant Technologies, Ltd.
Priority date: 2005-12-02
Filing date: 2006-10-30
Publication date: 2007-06-07
Also published as: JP2007152206A; JP4753158B2

Abstract

There is provided a dust collecting electrode plate of an electrical dust collector capable of reducing an element amplitude at a high flow rate, making hammer acceleration propagate over the entire element, and preventing a dust accumulating and fixing apparatus from falling. The dust collecting electrode plate (20) of the electrical dust collector (12) has a plurality of element members (40) formed in a longitudinally extending stripe shape and arranged in the same plane at constant intervals. The upper sides of these element members are linked with each other by an upper edge beam member (42), and the lower sides of these element members are linked with each other by a lower edge beam member (44). In this dust collecting electrode plate, a fastening piece (46) is provided for linking and fastening the adjacent side edges of the element members (40) having intervals in between, at at least one point between the upper edge beam member (42) and the lower edge beam member (44). In addition, the fastening piece (46) sandwiches the adjacent side edges by a pair of attaching plates (48, 49) and fastening parts (53, 54) for fastening the attaching plates, wherein at least one of the attaching plates is formed in a shape having a spring effect using a elastic deformation.

Description

Specification

Dust collector plate of electric dust collector

Technical field

TECHNICAL FIELD [0001] The present invention relates to a dust collecting electrode plate of an electric dust collecting device, and more particularly to a dust collecting electrode plate of a dry electric dust collecting device in which dust deposited and deposited on the dust collecting electrode plate is peeled and removed by a striking device.

Background art

In an electrostatic precipitator, dust collecting plates and discharge electrodes are alternately arranged in a dust collection chamber, and a high voltage is applied to the discharge electrodes to collect dust in a charged gas to be treated. Separated and collected by a plate. In addition, the dry electrostatic precipitator is provided with a hammering device, and the dust collector electrode is periodically beaten with a hammer of the hammering device, and deposited on the surface of the dust collector electrode plate. Dust is removed and removed.

[0003] The dust peeling and removal mechanism using a hammering device propagates vibration generated by hitting a hammering piece with a hammer to the element, and shears the dust adhering to the element by vibrating the element. It is to provide dust peeling force such as force and inertial force.

[0004] However, in this case, the portion where the acceleration of vibration propagating to the element is large, that is, the hammer hammer force is the closest element, and stress due to the strike is concentrated near the fixed portion with the strike beam, and the element cracks. Could occur.

[0005] In addition, in order to equalize the flow velocity of the gas flowing through the electrostatic precipitator, the force provided with the gas rectifying distribution plate at the inlet of the precipitator is still locally high at a flow velocity of about 3.5 mZ seconds. There is a certain point, and the amplitude of the element in the vicinity increases. For this reason, the separation distance between the dust collecting electrode plate and the discharge electrode cannot be maintained, and sparks are generated, resulting in poor charging, or high repeated stress is generated in the upper end fixing portion of the element, causing the element to fatigue. Dangerous.

[0006] In order to solve the above problem, the applicant of the present application has proposed a dust collection electrode plate in which the middle part of a plurality of elements is fixed by a single band member (for example, JP 2004-26 7957 A). Issue gazette). This is sandwiched between two flat bars via a round spacer and a square spacer, and a hole is made in the element and fixed with a bolt and nut. Fixing the band member Thus, the rigidity of the element member is increased and the striking force (strike acceleration) transmitted to the element is averaged, so that the element member is not cracked, and the element can be prevented from being damaged by the striking.

[0007] On the other hand, in a wet electrostatic precipitator, adjacent elements are fixed by a number of fixing devices to reduce vibration due to high-speed flow and to maintain a constant electrode pitch with the discharge electrode. Dust electrode plates have also been proposed (for example, JP-A-8-243433, JP-A-2001-232232).

Disclosure of the invention

Problems to be solved by the invention

[0008] However, when the element halfway portion is fixed with a single band member proposed in Japanese Patent Application Laid-Open No. 2004-267957, the amplitude is reduced, so that the occurrence of sparks and the repeated stress generated in the element fixing portion are reduced. Since the entire element is sandwiched by a single band member, dust could accumulate in the gap between the band member and the fixed part of the element.

[0009] Further, the fixing device for the dust collecting plate of the wet electrostatic precipitator proposed in Japanese Patent Application Laid-Open No. 8-243433 and Japanese Patent Application Laid-Open No. 2001-232238 is similar to each other in that the width of the fixing device is short. Adhesion with the element is weak because it is sandwiched between the bent parts at the tip of the element. For this reason

When this fixing device is applied to a dry electrostatic precipitator, the vibration caused by the strike required for the dry electrostatic precipitator is reduced near the fixing device, and the strike acceleration is not propagated throughout the element. In addition, since the adhesive force is weak, there is a risk that the fixing device may fall due to striking vibration.

[0010] The present invention has been made in view of such circumstances, and reduces the element amplitude at a high flow velocity, propagates the hitting acceleration throughout the element, and further collects dust and drops the fixing device. Means for Solving the Problems Aimed at Providing a Dust Collection Electrode Plate for an Electric Dust Collector

In the first aspect of the present invention, in order to achieve the above object, dust attached to the dust collecting electrode plate by striking the dust collecting electrode plate provided in the electric dust collector with a striking device. Peeling off In the electrostatic precipitator, the dust collecting electrode plate includes a plurality of element members formed in a vertically long strip shape arranged in parallel in the same plane with a certain gap therebetween. Adjacent to the dust collector electrode plate of the electrostatic precipitator in which the upper and lower sides of the member are connected by the upper end beam member and the lower end beam member, respectively, with the gap between the plurality of element members interposed therebetween. A fixed piece is provided to connect and fix the matching side portions at at least one place between the upper end beam member and the lower end beam member, and at least one of the fixed pieces uses a panel effect utilizing elastic deformation. It is the structure which pinches | interposes the said adjacent side part by the fastener which fastens a board | plate correspondingly with a pair of contact plate formed in the shape which has this, It is characterized by the above-mentioned.

[0012] The applicant of the present application has disclosed an electrostatic precipitator capable of reducing element amplitude at high flow velocity, propagating the strike acceleration to the entire element member, and preventing dust accumulation and dropping of the fixing device. Intensive research on dust collecting electrode plates. As a result, it was found that it is effective to connect element members in order to reduce the element amplitude and propagate the hitting acceleration throughout the element. Also, since dust accumulates in the gaps between the connecting members that connect the element members, using a fixed piece to connect adjacent element members with a minimum fixed area suppresses dust accumulation. I found out that I can do it. Furthermore, in order to prevent the fixing member from dropping, the element members are connected by a fixing piece having a structure in which the element member is sandwiched by a panel effect using elastic deformation when the fixing piece is bolted. It was found to be effective in preventing the fall of

[0013] Therefore, according to the first aspect of the present invention, the plurality of element members of the dust collecting electrode plate are arranged so that the side portions adjacent to each other with the gap between the plurality of element members sandwiched between the upper end beam members. A fixed piece that is connected and fixed at at least one point between the beam member and the lower end beam member, and at least one of the fixed pieces corresponds to a pair of contact plates formed in a shape having a panel effect using elastic deformation. This is a fastener that fastens the plates together so that adjacent sides are sandwiched between each other, reducing the element amplitude at high flow velocity, propagating the striking acceleration throughout the element, and further collecting dust. And it is possible to prevent the fixing member from falling [0014] A second aspect of the present invention is the first aspect of the invention according to the first aspect, wherein the fixed piece is a plate-shaped first contact plate applied to one surface of the side portions with the gap interposed therebetween, A second contact plate that is applied to the other surfaces of the side portions across the gap and has a vertical cross-sectional shape, and the first contact plate and the second contact plate through the clearance. And a fastening bolt for fastening together.

[0015] According to the second aspect, with such a structure, the element member can be sandwiched by a panel effect using elastic deformation when the fixing piece is bolted, so that the fixing member can be effectively dropped. Can be prevented.

The invention's effect

[0016] As described above, according to the electric dust collector of the present invention, the middle part of the plurality of element members constituting the dust collecting electrode plate excluding the upper and lower short sides thereof is formed by a single band member. Since they are connected, the rigidity of the element member can be increased without increasing the thickness of the element member, and this causes the striking force transmitted to the element member to be averaged, so that cracks occur in the element member. Without damage, it is possible to prevent the dust collecting electrode plate from being damaged by the hammering device. Brief Description of Drawings

[0017] FIG. 1 is an explanatory diagram of a coal combustion ash treatment facility provided with the electric dust collector of the present invention.

FIG. 2 is a front view showing the dust collecting electrode plate structure of the electric dust collector of the present invention.

[Fig.3] Cross section of dust collecting electrode plate

[Figure 4] Enlarged cross-sectional view of the main part showing when the fixed piece is installed

[Fig.5] (a) Cross-sectional view of the fixed piece when the fixed piece is installed before tightening the bolt and (b) after tightening the bolt

[Figure 6] Graph showing the relationship between flow velocity and element amplitude

[Figure 7] Table showing the effect of fixed piece installation

[Fig.8] Front view explaining acceleration measurement points on dust collection electrode plate

[Fig. 9] Graph showing striking acceleration propagating from the striking side to the (a) 1st sheet, (b) 5th sheet, and (c) 9th element when the fixed piece is installed

Explanation of symbols

[0018] 10 · · · Coal-fired boiler, 12… Electric dust collector, 18 · · Discharge electrode, 20… Dust collector plate, 26 · · · tJ ^, 27 · · · Noma, 28 · · · Hono, 40 · · · Element, 42 · · · Suspension, hum, 44, ΫΪ Beam, 46 ... Fixing piece (fastening member), 48 ... Hat-shaped member (second pad), 49 ... Plate-shaped member (first pad), 53 ... Bolt, 54 ... · Nut, 57 ··· Folded portion of element end BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the electrostatic precipitator according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an electric dust collector 12 that removes combustion ash (hereinafter referred to as dust) in combustion gas generated from a coal combustion boiler 10 of a thermal power plant.

The gas containing dust generated from the coal combustion boiler 10 is heat-exchanged by the air heater 14 and the gas-gas heater 16a, and then flows into the electrostatic precipitator 12.

The gas taken into the dust collection chamber of the electric dust collector 12 passes between the discharge electrode 18 and the dust collection electrode plate 20. A DC voltage is applied between the discharge electrode 18 and the dust collecting electrode plate 20 from the power supply device 23, and dust in the gas is charged by the corona discharge generated at that time, and adheres to and collects on the dust collecting electrode plate 20. Is done.

[0023] The clean gas from which dust has been removed is supplied from the electrostatic precipitator 12 to the desulfurizer 22, where sulfur oxides are removed, and then heated by the gas gas heater reheating unit 16b, and then the chimney. 24 Force Released into the atmosphere.

[0024] In the electrostatic precipitator 12, the dust adhering to the dust collecting electrode plate 20 is peeled and removed from the dust collecting electrode plate 20 by the striking operation of the hammer 27 shown in FIG. The electric dust collector 1 falls to a hopper 28 provided at the bottom of the electric dust collector 12. The dust that has fallen and accumulated on the hopper 28 is discharged from the hopper 28 by opening the rotary valve 30, and the discharged dust is conveyed to the ash treatment device 34 by the screw compressor 32.

As shown in FIG. 2, the dust collecting electrode plate 20 includes nine elements 40, 40..., A suspended beam (upper beam member) 42, a striking beam (lower beam member) 44, and Fixed piece (piece member) 46, 46… Established.

[0026] The element 40 is a vertically long strip having a length of 15 m, a width of 60 cm, and a thickness of 1.2 mm, with a cross-section as shown in Fig. 3 (cross-sectional view taken along line I-I in Fig. 2). These 9 elements are made of sheet steel, and the long sides on the left and right sides are juxtaposed on the same plane with the sides of the elements 40 and 40 adjacent to the left and right. 40, 40 ... the upper short side is hung In addition to being fixed by the beam 42, the lower short sides of the nine elements 40, 40... Are fixed by the striking beam 44.

[0027] The suspended beam 42 is composed of a pair of beam members, and the upper short sides of the elements 40, 40... Are sandwiched between these beam members, and both are fixed by screws 50, 50.ヽ. The suspended beam material 42 is provided with a suspended Bonoleto 52, 52 force S, and the suspended Bonoleto 52, 52 force ^ is fastened to the ceiling of the dust collection chamber to suspend the dust collection electrode 20 from the dust collection chamber. Favored

[0028] The striking beam 44 is also composed of a pair of beam materials, and the elements 40, 40 ... lower short side portions are sandwiched by these beam materials and both are fixed by screws 56, 56 ... ing. Further, a striking piece 58 projects from one end of the striking beam 44. When the strike piece 58 is beaten by the hammer 27, the vibration generated thereby propagates to the elements 40, 40, and the element 40, 40-vibrates. As a result, a dust peeling force such as a shearing force is applied to the element 40, 40 • · −, and the dust is peeled and removed from the element 40, 40 • · −. In this case, it is known that the stress due to the hammer 27 is concentrated at a site where the acceleration of vibration propagating to the element 40 is large.

FIG. 4 is an enlarged front view of the installation part of the fixed piece 46, and FIGS. 5 (a) and 5 (b) are cross-sectional views showing a cross section taken along line II-II of FIG. The fixed piece 46 is formed by a cap-shaped member (second patch plate) 48 and a plate-shaped member (first patch plate) 49, two sets of fasteners, a bolt 53 and a nut 54. The shaped member 49 is sandwiched between adjacent element ends from both sides, and is fixed to the gap between the elements through two bolts 53 and 53. Here, the cap-shaped member 48 is adapted to fit into the folded-back portions 57 of the two adjacent element ends, but as shown in FIG.5 (b), the fixing piece 46 after tightening the bolt 53 also has a sectional force. As seen, the cap-like member 48 and the plate-like member 49 are elastically deformed by the tightening force. In this way, the cap-shaped member 48 and the plate-shaped member 49 are elastically deformed, so that a panel effect is generated, and the fixing piece 46 and the element 40 can be firmly adhered and fixed.

[0030] In the dust collecting electrode plate of the electric dust collecting electrode having such a configuration, the elements 40, 40, ... are connected by connecting the fixed pieces 46, 46, ..., elements 40, 40, ... As well as reducing the amplitude of dust, it is possible to reduce the accumulation of dust that occurs in the gap between the fastening member 46 and the fixed part of the element. wear. Further, when the fixing piece 46 is tightened, it is possible to firmly fix the element 40 with the element 40 by utilizing the panel effect due to the elastic deformation of the cap-like member 48 and the plate-like member 49. Thereby, it is possible to propagate the hitting acceleration throughout the element and to prevent the fixed piece 46 from dropping due to hitting vibration.

FIG. 6 shows the effect when the fixed piece 46 according to the present invention is attached to the dust collecting electrode plate in relation to the wind speed and the element amplitude. In the actual electrostatic precipitator 12, there is a local area where the flow velocity is as high as about 3.5mZ seconds, but as can be seen from Fig. 6, by installing the fixed piece, the amplitude of the fixed piece It can be reduced to about one-third compared to the one without it. By reducing the amplitude of the element, as shown in Table 1 in Fig. 7, the minimum separation distance from the discharge line is expanded to about 115 m, and the maximum repetitive stress generated at the upper end of the element is increased from about 140 MPa. It can be reduced to 50MPa. Further, by using the fixed piece 46 according to the present invention, it is possible to reduce dust accumulated on the fixed portion with the element.

[0032] FIG. 8 shows the effect of mounting the fixed piece 46 according to the present invention on the dust collecting electrode plate in order to show the relationship between the distance of the element lower end force and the striking acceleration of the elements 40, 40,. It is a front view of a dust collection electrode plate showing acceleration measurement points.

FIG. 9 shows the relationship between the distance of the element lower end force and the hitting acceleration as an effect when the fixed piece 46 according to the present invention is attached to the dust collecting electrode plate. The fixed piece 46 has a structure that can be fixed by elastically deforming the fixed piece 46 at the time of bolt tightening and firmly adhering to the element by its panel effect, as shown in FIG. The batting acceleration (1200mZsec ² or more) can be propagated throughout the element. In addition, in FIG. 9, only the first, fifth, and ninth elements from the strike side are displayed. All other elements similarly satisfy the above-described strike speed. Furthermore, since the adhesive strength with the element is strong, it is possible to prevent the fixed piece from dropping due to striking vibration.

Claims

The scope of the claims

[1] An electric dust collector that peels and removes dust adhering to the dust collector electrode plate by striking the dust collector electrode plate provided in the electric dust collector device with a hammering device, the dust collector electrode plate A plurality of element members formed in a vertically long strip shape are arranged in parallel in the same plane with a certain gap, and the upper and lower sides of the plurality of element members are upper end beams. In the dust collector electrode plate of the electrostatic precipitator connected by the member and the bottom beam member,

A fixing piece is provided for connecting and fixing side portions adjacent to each other across the gap of the plurality of element members at at least one place between the upper beam member and the lower beam member, and the fixing piece is And a structure in which at least one of the side plates adjacent to each other is sandwiched between a pair of contact plates formed in a shape having a panel effect utilizing elastic deformation and a corresponding fastener for fastening the plates together. Dust collector electrode plate for electric dust collector.

[2] The fixed piece is

A plate-like first contact plate that is applied to one surface of the side portions with the gap interposed therebetween, and a vertical cross section that is applied to the other surface of the side portions with the gap interposed therebetween. A second cauld plate with

A fastening bolt for fastening the first and second contact plates through the gap;

The dust collection electrode plate of the electrostatic precipitator according to claim 1, further comprising: