JPH0647310A - Electric dust collecting apparatus - Google Patents

Abstract

PURPOSE:To improve dust collecting efficiency of an electric dust collecting apparatus by effectively peeling and dropping powder dust sucked to and captured on the dust collecting surface and keeping the dust collecting surface clean constantly. CONSTITUTION:A dust collecting part 12 is composed of two porous plates 18, a first water storage tank 20 is installed in the upper end part, and a second water storage tank 34 is installed below while keeping a gap between them. Water is supplied to the first water storage tank 20 from the side face 26 and is sent to the second water storage tank 34 through a large number of holes 24 pierced in the bottom face of the first water storage tank 20. The water which overflows the second water storage tank 34 is led to flow downward on the porous plates 18 and to peel the powder dust, so that the surfaces of the porous plates 19 are kept clean and thus the dust collecting efficiency of an electric dust collecting apparatus can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic precipitator, and more particularly to a dust collecting section thereof.

[0002]

2. Description of the Related Art An electrostatic precipitator utilizing corona discharge is
By applying a high voltage between the discharge electrode and the dust collection electrode, which creates an unequal electric field in the air, a corona discharge is generated between the discharge electrode and the dust collection electrode to ionize the air in the strong electric field. By generating a charge band and flowing the process gas through the charge band generated between the discharge electrode and the dust collecting electrode, the particles such as dust and various bacteria contained in the process gas are charged and the charged particles are reversed. It is attached to the dust collecting electrode of the electric potential and collected.

FIG. 6 is a plan view of an essential part showing a conventional technique of a commonly used electrostatic precipitator. In the figure,
The dust collecting part 40 has plate-like dust collecting electrodes 42, 42 provided in parallel along the flow path of the processing gas, and the discharging part 44 has the dust collecting electrodes 42, 42.
Has a discharge electrode 52 formed by a flat plate 46 extending in the middle portion of the flat plate 46, and needle-like pieces 50, 50 fixed by stoppers 48, 48 on the gas inflow side and the gas outflow side of the flat plate 46, respectively. There is. And, the needle-like pieces 50, 50 are planted at a predetermined pitch along the respective ends of the flat plate 46 on the gas inflow side and the gas outflow side, and their tips are respectively on the gas inflow side and the gas outflow side. It has been extended.

In the electrostatic precipitator thus constructed, the discharge electrodes 52,52 are provided between the dust collecting electrodes 42,42 and the discharge electrodes 52,52.
When a high voltage is applied to make the negative electrode, a corona discharge as indicated by a dotted line is generated from the tips of the needle-shaped pieces 50, 50 toward the dust collecting electrodes 42, 42. On the other hand, when the processing gas containing dust flows as indicated by the arrow, most of the dust passing through the corona discharge area is negatively charged. Therefore, a portion where this corona discharge is occurring constitutes a charge zone, and the dust charged in this charge zone is generated between the dust collecting electrodes 42, 42 and the discharge electrodes 50, 50. The high electric field
The dust is attracted to the dust collecting electrodes 42, 42 and collected on the surface of the dust collecting electrodes 42, 42.

FIG. 8 shows that the inventor of the present invention has already invented
It is a principal part perspective view of the commercialized electrostatic precipitator. In this electrostatic precipitator, a discharge part 68 in which a discharge band 62 in which a needle-shaped piece 60 is implanted and a hollow metal rod 64 are alternately arranged, and a hollow metal rod 70 are arranged along the discharge part 68. It is constituted by the dust collecting unit 72 provided. Then, in the electrostatic precipitator configured as described above, strong corona discharge is generated from the tip of each needle-shaped piece 60 toward the dust collecting part 72, and dust is attracted to the surface of the hollow metal rod 70 of the dust collecting part 72. To be collected. It should be noted that since the dust collecting portion 72 is formed of the aggregate of the hollow metal rods 70, the surface area as a whole is increased, and thus the dust collecting efficiency can be improved.

[0006]

However, since the above-mentioned conventional electrostatic precipitator collects the charged dust by suction on the surface of the flat plate or the surface of the hollow metal rod, the electrostatic dust collector once collects the dust on the surface. It was difficult to remove the dust adhering to the. As a measure to solve this problem, impact the dust collection part with a hammer etc. to peel off the dust,
Measures such as collection were taken. However, even with such a method, it is impossible to completely remove dust,
Further, due to the impact, a part of the collected dust is scattered, and as a result, the dust collection efficiency is reduced.

The present invention has been made in view of the above problem, and the collected dust is completely separated and dropped without being impacted by a hammer or the like, and the dust is efficiently collected to improve the dust collection efficiency. That is the purpose.

[0008]

In order to achieve the above object, the constitution of the present invention is as follows. That is, in the electrostatic precipitator in which the dust collecting part and the discharging part are arranged to face each other with a predetermined distance therebetween, the dust collecting part is formed by a perforated plate, and liquid is placed on the perforated plate on the perforated plate. Flow it into a film,
A liquid storage part for washing away the dust collected on the perforated plate is provided. Further, the holes of the perforated plate are circular, elliptical, rhombic or triangular.

[0009]

With the above-described structure, the dust collected by suction on the plate surface of the perforated plate in the dust collecting portion is generated by the liquid flowing in the form of a film from the liquid storage portion provided above the perforated plate. , Together with the liquid, is flowed below the perforated plate. This ensures that the dust collecting portion is always kept clean. Further, by making the shape of the holes of the perforated plate circular, elliptical, rhombic, or triangular, the liquid easily flows down in the form of a film, and the flow of dust can be further promoted.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings. First, the schematic configuration of the electrostatic precipitator 10 will be described with reference to FIG. The electrostatic precipitator 10 is composed of a later-described dust collecting part 12 and two electrode parts 14 and 14 which are separated by a predetermined distance so as to sandwich the dust collecting part 12 and are installed in a duct 16. . Further, the dust collecting part 12 is provided with two perforated plates 18, 18 described later so as to face the electrode parts 14.

In the electrostatic precipitator thus constructed, when a high voltage is applied between the dust collecting part 12 and the electrode parts 14, 14 so that the dust collecting part 12 becomes the positive electrode and the electrode parts 14, 14 become the negative electrode. , Corona discharge is generated from the electrode parts 14, 14 toward the dust collecting part 12. On the other hand, when the processing gas containing dust flows in the duct 16 as shown by the arrow, most of the dust passing through the corona discharge area is negatively charged. Therefore, the part where this corona discharge is occurring constitutes a charge band, and the dust charged in this charge band is a high electric field generated between the dust collecting part 12 and the electrode parts 14, 14. As a result, the dust is sucked into the dust collecting part 12 and collected on the surfaces of the perforated plates 18, 18.

Next, referring to FIGS. 1 to 3, the dust collecting portion 12 having the features of the present invention will be described. Pipe members 20 and 22 having a rectangular cross section for connecting the two perforated plates 18 and 18 are arranged at the upper end and the lower end of the dust collecting unit 12, respectively. The rectangular pipe member 20 provided at the upper end is a first water tank, and a large number of holes 24 are formed in the lower surface thereof. In addition, on the side surface 26 facing the vertical surface of the duct 16, water from the outside is stored in the first water tank 20.
A water supply pipe 28 for leading to the above is connected via a water supply valve 30.

Below the first water tank 20, there is a predetermined gap 32, for example, a space of 10 mm, and in parallel to the first water tank 20, a second water tank 34 having a rectangular cross section as shown in FIG. Is provided. Further, both longitudinal ends thereof are closed.

By the way, the holes 36 of the perforated plate 18 are formed in a circular shape, and are arranged at a predetermined interval in the horizontal direction, and in the vertical direction, the positions of the adjacent holes are displaced left and right. ing. Thereby, as described later, the water flowing from above on the plate surface of the perforated plate 18 can flow downward while circling around the respective holes 36 and evenly spreading over the plate surface. The shape of the holes 36 of the perforated plate 18 is not limited to a circular shape, and the same effect can be obtained as long as it has a symmetrical shape with respect to the vertical axis, such as an oval shape, a rhombus shape, or a triangle having an apex at the top.

Next, an explanation will be given of the separating action of the dust collected in the above-structured electrostatic precipitator, especially in the dust collecting part thereof. The water, which has passed through the water supply valve 30 from the outside, is introduced into the first water storage tank 20 and drops into the second water storage tank 34 below from the hole 24 formed in the bottom surface thereof. After filling the second water tank 34, the water overflows to the outside, and as described above, flows evenly over the surface of the perforated plate 18 onto the film. The flow rate of water in this case is adjusted by adjusting the opening degree of the water supply valve 30, and the first water tank.
Control is performed by appropriately setting the total area of the holes 24 formed in the bottom surface of the 20. As a result, the dust collected on the surface of the perforated plate 18 is separated by water and flows downward, and is collected and transferred together with water to a predetermined treatment facility.
The water may be supplied continuously or intermittently depending on the amount of dust collected on the surface of the porous plate 18.

The electrostatic precipitator provided with the above-mentioned dust collector is used when it is required to collect 100% of the target dust and when it can be treated using water. For example, it is particularly effective when it is necessary to collect and collect the radioactive dust scattered during the cutting operation of nuclear fuel waste without leakage.

[0017]

As is apparent from the above description, the dust collecting portion is formed by the perforated plate, and the liquid storage portion for dropping the liquid in the form of a film on the surface of the perforated plate is provided above the perforated plate. As a result, the dust collected by suction on the surface of the perforated plate can be effectively separated and flowed downward together with the liquid, and the surface of the perforated plate can be constantly kept clean. The efficiency can be improved. Also, by forming the holes of the perforated plate in a circular, elliptical, rhombic or triangular shape,
The liquid that drops on the surface of the porous plate easily travels around the holes, and therefore can flow evenly on the surface of the porous plate, so that the dust collected by suction can be efficiently separated and dropped. Thereby, the dust collection efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view of a dust collecting portion showing an embodiment of the present invention.

2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a perspective view showing a second water storage tank.

4 is a schematic plan view of an electrostatic precipitator including the dust collector of FIG. 1. FIG.

FIG. 5 is a plan view showing a conventional technique.

FIG. 6 is a plan view showing another conventional technique.

[Explanation of symbols]

 10 Electrostatic precipitator 12 Dust collector 14 Discharge part 16 Duct 18 Perforated plate 20 First water storage tank 34 Second water storage tank 36 holes

Claims (2)

[Claims] 1. An electrostatic precipitator in which a dust collecting part and a discharging part are opposed to each other with a predetermined distance therebetween, and the dust collecting part is formed of a perforated plate, and the liquid is placed on the perforated plate above the perforated plate. An electrostatic precipitator provided with a liquid storage section for washing the dust collected on the perforated plate in a film shape on the surface. 2. The shape of the holes of the perforated plate is circular, oval,
The electrostatic precipitator according to claim 1, wherein the electrostatic precipitator is a rhombus or a triangle.