JP2686881B2 - Dust collecting electrode of wet electrostatic precipitator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dust collecting electrode of a wet electrostatic precipitator capable of forming a uniform liquid film on its surface.

[0002]

2. Description of the Related Art A wet electrostatic precipitator or a dry electrostatic precipitator is widely used to collect polishing dust, paint mist or other fine particles generated in a polishing factory, a painting factory or another factory. Has been. These electrostatic precipitators suck air containing dust and discharge the dust between the discharge electrode and the receiving electrode (dust collecting electrode) to corona-charge the dust and collect the charged dust. It is what is sucked into the dust pole.

The dry type dust collector is constructed so that the dust and the like adhering to the surface of the dust collecting electrode are dropped by hitting and vibrating the dust collecting electrode. In addition, the wet electrostatic precipitator
A fluid such as water is supplied to the surface of the dust collecting electrode to form a liquid film on the surface of the dust collecting electrode so that the liquid film flows down, and the dust film sucked by the dust collecting electrode is removed by the flowing down liquid film. It is configured.

In the above wet electrostatic precipitator, it is necessary to form a uniform liquid film on the surface of the precipitator. For this reason, a device is provided in which a weir is provided above the dust collecting electrode, and a fluid is supplied through the weir to form a uniform liquid film on the surface of the dust collecting electrode so that the liquid film flows down.

[0005]

However, even with the wet electrostatic precipitator as described above, it is difficult to form a uniform liquid film by the fluid supplied to the surface of the precipitator. For this reason, there is a problem that uneven discharge occurs and lumps of dust are attracted to the surface of the dust collecting electrode. Then, once the lumps are formed, the liquid film becomes more and more non-uniform, and there is a problem that the lumps grow and the suction ability decreases.

Further, as a known technique in which the tubular body is made of a material having water permeability as in the present invention, there is, for example, Japanese Patent Laid-Open No.
There are techniques disclosed in Japanese Patent Publication No. 8-058157, Japanese Utility Model Publication No. 43-012238, etc., but these techniques merely cause the fluid exuding the tubular body to flow down uniformly along the tubular body. There is a problem that it is difficult to completely remove dust such as dust adhering to the particles.

The object of the present invention is to always form a uniform liquid film on the surface and to reliably remove the dust adhering to the surface of the dust collecting electrode by the fluid leached with a stronger pressure than the wall surface of the cylindrical body. It is to provide a dust collecting electrode of a wet electrostatic precipitator.

[0008]

In order to solve the above problems, a first invention of a dust collecting electrode of a typical wet electrostatic precipitator according to the present invention is a cylinder whose lower part is closed by a material having water permeability. A dust collecting electrode for a wet electrostatic precipitator, which is characterized by forming a cylindrical body and supplying and filling a fluid having conductivity inside the cylindrical body. Further, the gist of the second invention of the dust collecting electrode of the present invention is that the cylindrical body is formed by coating the peripheral surface of a cylinder having a large number of holes on its peripheral surface with a material having water permeability. It is a dust collecting electrode of the wet type electrostatic precipitator of the first invention characterized.

[0009]

According to the dust collecting electrode of the wet electrostatic precipitator (hereinafter, simply referred to as "dust collecting electrode"), the fluid constantly leached from the inside of the cylindrical body to the outside on the surface of the dust collecting electrode with a strong pressure. It is possible to form a uniform liquid film.

That is, since the tubular body is formed by closing the lower part of the material having water permeability, when the fluid having the conductivity is supplied to the inside of the tubular body to fill it, the filled fluid is The fluid pressure of the fluid permeates the wall of the cylindrical body with a strong pressure and exudes to the surface. When the amount of the fluid leached on the surface of the tubular body exceeds a certain limit, the fluid flows down along the surface of the tubular body, forming a uniform liquid film on the surface of the tubular body. In this state, if an electric discharge is made between the discharge electrode and the dust collecting electrode (fluid supplied to the cylindrical body), the dust contained in the gas such as air, steam, and gas will be corona charged to the dust collecting electrode. It is sucked and further removed by the fluid flowing down the surface of the dust collecting electrode.

In particular, in the case of collecting mist consisting of chemicals, by using a chemical having conductivity as a fluid and capable of neutralizing the chemical components of the mist, it is possible to chemically collect mist at the same time as collecting mist. It is possible to easily carry out post-treatment by neutralizing to.

[0012]

EXAMPLES Examples of the dust collecting electrode will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the overall structure of a wet electrostatic precipitator, and FIG. 2 is a partially enlarged view for explaining the structure of a dust collector. The wet dust collector A according to this embodiment is a device for collecting dust and mist contained in air, dust, mist, and fine particles contained in air or steam or gas.
The dust collecting electrode B is constituted by a tubular body 1 whose lower part made of a water-permeable material is closed by a cup-shaped mounting member 11, and supplies a conductive fluid to the inside of the tubular body 1. The liquid is leached on the surface of the dust collecting electrode B to form a uniform liquid film and can flow down.

In the figure, a wet dust collector A is constructed by arranging a plurality of cylindrical bodies 1 serving as a discharge electrode 3 and a dust collecting electrode B inside a casing 2.

The casing 2 has watertightness and airtightness, and is formed with an inlet 2a and an outlet 2b for a gas such as air, steam or gas containing dust, mist, fine particles and the like.
A partition wall 4 is provided on the upper part of the casing 2, and a supply chamber 5 for supplying a conductive fluid to the inside of the cylindrical body 1 (see FIG. 2) is formed on the partition wall 4. A storage chamber 6 for storing the fluid flowing down from the tubular body 1 is formed in the lower portion of the casing 2. The supply chamber 5 and the storage chamber 6 are connected by a pipe 7 having a pump 7a,
A fluid supply source 8 is connected to the pipe 7. The storage chamber 6 is connected to the ground 9.

A plurality of nipple-shaped projections 4a for attaching the upper end of the tubular body 1 are formed at predetermined positions of the partition wall 4. Further, a plurality of supporting members 10 having both ends fixed to the casing 2 are arranged at a position below the fluid level of the storage chamber 6, and the cylindrical body 1 is provided at a position facing the protrusions 4 a provided on the partition wall 4 of the supporting members 10. A cup-shaped mounting member 11 capable of closing the lower end is arranged. The attachment member 11 attaches the lower end of the tubular body 1, and is attached to the support member 10 via a spring 12.

The discharge electrode 3 is arranged in the vertical direction so as to face the cylindrical body 1. The discharge electrode 3 has an electrically conductive arm 3a, which is supported by the casing 2 by fixing the arm 3a to the insulator 13 and can be discharged by being connected to the power supply 14. .

The cylindrical body 1 forming the dust collecting electrode B is formed by forming a material having water permeability into a cylindrical shape. Examples of the material having water permeability include a cloth-like material in which fibers are woven in the length and width, a felt-like material in which fibers are strained, and a sponge-like material. These materials are capable of retaining fluid between the fibers. The fluid also penetrates through the interstices between the fibers. In such a tubular body 1, it is possible to adjust the amount of fluid that can be held and the amount of permeation per unit time by appropriately setting the density of fibers.

In the experiments conducted by the inventor of the present invention, when natural fibers such as cotton, hemp, and silk and sponges are used as the material of the tubular body 1, the fluid can be retained in a good state. Even if the body 1 was lengthened, it was possible to form a uniform liquid film from the upper end to the lower end. However, when synthetic fibers such as nylon are used as the material of the tubular body 1, the holding power for fluid is inferior to that of natural fibers, and when the tubular body 1 is long, the liquid film is at the lower end side. Formed only on
When the length of the tubular body 1 was short, it was possible to form a uniform liquid film over the entire length. In the present embodiment, as the material for the tubular body 1, a zucks woven of hemp fibers is used.

One end (lower end) of the cylindrical body 1 is attached to a mounting member 11 provided on a supporting member 10, the outer periphery is fixed by a band 15, and the other end (upper end) is provided on a partition wall 4. The tubular body 1 can be attached to the casing 2 by inserting and folding back the protrusion 4a and fixing the outer periphery of the folded back portion with the band 15.
In FIG. 1, reference numeral 16 is a rectifying plate for rectifying the gas introduced into the casing 2.

In the wet dust collector A constructed as described above, when the valve 7b of the pipe 7 is opened and the pump 7a is operated, the fluid stored in the storage chamber 6 is supplied to the supply chamber 5. . When the fluid is supplied above the level of the protrusions 4a provided on the partition wall 4, the fluid overflows from the upper end of the tubular body 1 and is supplied into the tubular body 1 and gradually filled from the lower side to the upper side. When the level of the fluid filled in the tubular body 1 rises, the pressure of the liquid increases and gradually permeates the wall of the tubular body 1 and uniformly leaches to the outer surface with a strong pressure. . Further, when the cylindrical body 1 is expanded due to the weight of the fluid inside the cylindrical body 1, the expansion is absorbed by the elastic deformation of the spring 12.

The leaching level rises as the liquid level inside the cylindrical body 1 rises. The internal liquid level of the tubular body 1 is the partition wall 4
When reaching the protrusion 4a, the leaching level rises to near the maximum point, and the fluid inside leaches over the entire length of the tubular body 1 to the outside uniformly with strong pressure. The fluid leached on the surface of the tubular body 1 becomes a uniform liquid film with the increase of the leaching amount, flows down along the surface of the tubular body 1, and is stored in the storage chamber 6.

The amount of fluid that permeates the cylindrical body 1 and flows down is
It is determined according to the material of the material forming the tubular body 1, the density of the fibers, the inner diameter of the tubular body 1, the specific weight of the fluid, and the like. That is, when each of the above conditions is set, the flow rate of the fluid per unit time is set. Therefore, by operating the pump 7a to replenish the fluid in accordance with the flow rate, the fluid level in the supply chamber 5 is kept constant, whereby the cylindrical body 1 is supplied and filled with a constant amount of fluid. Is possible.

As described above, a uniform liquid film is formed on the surface of the cylindrical body 1, and a blower or the like (not shown) is operated while discharging from the discharge electrode 3 to suck a gas containing dust into the casing 2. Then, dust or the like between the discharge electrode 3 and the tubular body 1 is corona-charged and attracted to the surface of the tubular body 1. Then, dust and the like are removed from the surface together with the fluid flowing down along the surface of the tubular body 1 and stored in the storage chamber 6. Dust and the like adhering to the surface of the tubular body 1 can be completely removed by the pressure of the fluid leached from the inside of the tubular body 1 to the outside.

Therefore, a water treatment device (not shown) is connected to the pipe 7 according to the properties of dust or the like to be removed, and the pump 7a is connected.
Is driven to pass the fluid in the storage chamber 6 through the water treatment device to process the fluid according to the property of dust or the like and circulate the fluid in the supply chamber 5 to collect dust or the like from the sucked gas. In addition, it is possible to remove the collected dust and the like to the outside.

The tubular body 1 is preferably capable of withstanding permanent use. However, depending on the nature of dust or the like to be collected, there is a risk of deterioration over time of use. In such a case, replacement is performed by releasing the band 15 from the protrusions 4a of the tubular body 1 and the mounting member 11 and removing them, and attaching a new tubular body 1 to the protrusions 4a and the mounting member 11. It is possible to

FIG. 3 is a perspective view of another cylindrical body 21 that can be used as the dust collecting electrode B. The tubular body 21 has a large number of holes.
A peripheral surface of a cylinder 22 having 22a is covered with a cylinder 23 made of the same material as that of the cylindrical body 1 described above. Even when the cylindrical body 21 is attached to the wet dust collector A and a fluid is supplied into the cylinder 22, a uniform liquid film is formed on the surface of the cylindrical body 23 as in the case of the cylindrical body 1 described above and flows down. It is possible to

The cylinder 22 is not limited to one having a large number of holes 22a formed in its peripheral surface as shown in FIG.
For example, the cylinder 22 may be made of a mesh material. Further, the material of the cylinder 22 is not particularly limited, and a stainless steel pipe or a steel pipe having a large number of holes formed therein, or a net-shaped material made of stainless steel or steel formed into a pipe shape, etc. may be used. Is possible. When such a cylinder 22 is used, the cylinder 22 is attached to the mounting member 11 and fixed by the band 15 as shown in FIG.
To function as an electrode, whereby the dust collecting electrode B can be configured.

It is also possible to form a large number of holes in a synthetic resin pipe and use it as the cylinder 22. In this case,
By supplying a fluid having conductivity inside the tubular body 21, the entire tubular body 21 can be configured as the dust collecting electrode B.

[0029]

As described above in detail, the dust collecting electrode of the wet dust collecting apparatus according to the present invention is supplied and filled into the inside of a cylindrical body which is formed of a material having water permeability and whose lower portion is closed. The fluid permeates the tubular body with a strong pressure due to the fluid pressure and leaches to the surface, and the fluid flows down along the surface of the tubular body. Therefore, by continuing the flow-down state, it is possible to always form a uniform liquid film on the surface of the cylindrical body. Therefore, it is possible to remove the dust and the like adhering to the cylindrical body with the pressure for leaching the fluid, and there is no possibility that lumps of dust or the like will adhere to the surface of the dust collecting electrode, and good dust collecting performance is maintained. It has features such as being able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a wet electrostatic precipitator.

FIG. 2 is a partially enlarged view illustrating a structure of a dust collecting electrode.

FIG. 3 is a perspective view of a tubular body according to another embodiment.

FIG. 4 is a side view in which a tubular body according to another embodiment is attached to an attachment member.

[Explanation of symbols]

 A wet type dust collector B dust collector 1 tubular body 2 casing 3 discharge electrode 4 partition wall 4a projection 5 supply chamber 6 storage chamber 10 support member 11 mounting member 12 spring 14 power supply 15 band 21 tubular body 22 tubular 22a hole 23 tubular body

Claims (2)

(57) [Claims] 1. A wet electrostatic collector characterized in that a tubular body whose lower portion is closed by a material having water permeability is formed, and a fluid having conductivity is supplied to fill the inside of the tubular body. Dust collector electrode. 2. The wet electrostatic precipitator according to claim 1, wherein the cylindrical body is formed by covering the peripheral surface of a cylinder having a large number of holes on its peripheral surface with a material having water permeability. Device dust collection pole.