KR101105306B1 - System for Maintenance of Uniform Water-Film on Wet Electrostatic Precipitator - Google Patents

Abstract

The present invention relates to a technique for maintaining a uniform washing water film on the surface of the dust collecting plate of the wet dust collector. The present invention includes a washing water amount adjusting device and a washing water film thickness adjusting device, and the washing water amount adjusting device further includes an electric field generating device for generating an electric field in the washing water flowing between the plate-shaped control panel and the dust collecting plate. The thickness adjusting device includes a current supply device for flowing a DC current to the washing water supplied from the washing water supply unit, and further includes an acid coating agent supply unit for supplying the acid resistant coating agent when the washing water is supplied.

Therefore, as well as maintaining a uniform water film on the surface of the dust collecting plate, by freely adjusting the thickness of the water film as necessary, the efficiency of the wet electrostatic precipitator can be increased, and generation of dry spots and blue haze can be suppressed.

Description

System for Maintenance of Uniform Water-Film on Wet Electrostatic Precipitator}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the maintenance of a uniform water film of a dust collecting plate of a wet electrostatic precipitator, and more particularly, to a technique of maintaining a uniform water film on the surface of a dust collecting plate using the principle of electrodeposition coating.

Electrostatic precipitators have been widely used as a device for removing particulate contaminants generated in industrial sites, and researches on general single particle contaminants have been conducted by many researchers. However, in recent years, the concentration of ultrafine dust particles and new trace harmful air pollutants, such as heavy metals and white lead, has become stronger. New dust collection and harmful gas removal technologies for complex pollutants are required.

Currently, Korea's annual standard for fine dust is expected to be strengthened from 70 to 50μg / m ³ , but this is still higher than 20μg / m ³ , which is the California standard in the US. In the United States, the United States announced that in December 2005, the regulation on the fine particles of Particulate Matter (PM) 2.5 will be further strengthened since December 2005. The focus is on the most important issues.

In 2010, Korea's emissions allowance standards for power plants and incinerators have been greatly strengthened, and emission charges have been reorganized, and emission allowance standards for new high-tech industrial facilities such as semiconductor manufacturing facilities and liquid crystal displays (LCDs) have been strengthened.

Even in processes using various hazardous chemicals such as semiconductor processes, fine dust, mist and various harmful chemicals, which are difficult to remove in existing dust collectors, are emitted as exhaust gases. Wet scrubbers and the like are used for the purification of such harmful exhaust gases, but reduction techniques using an effective wet electrostatic precipitator have been developed and applied due to limitations in their processing efficiency and structural problems.

The wet electrostatic precipitator (WESP) is composed of a discharge water, a dust collecting plate, and a high voltage applying device in addition to a washing water supply device and a circulation device. In order to remove the contaminants attached to the dust collecting plate in the dry electrostatic precipitator, instead of the rapping process, the wet electrostatic precipitator supplies the washing water to the dust collecting plate to remove the attached contaminants.

Wet electrostatic precipitators show excellent performance in controlling emissions of sub-micron microparticles, heavy metal particles, mist, fume, dioxin and furan, and gaseous contaminants. Dust collection efficiencies such as fiber filter or dry electrostatic precipitator are sensitive to the physical and chemical properties of the particles to be removed, while wet electrostatic precipitators can be applied to various anti-pollution facilities. It is effective for removing submicron particles regardless of their physical and chemical properties.

However, a general metal plate type wet electrostatic precipitator tends to be washed in the form of beads due to the initial imperfection of the installation of the dust collecting plate and the surface tension of the washing water and the dust collecting plate, thereby causing a dry spot in which the cleaning plate does not exist. This presence causes build up of the particles and reduces the current, which in turn is the main cause of impaired overall efficiency.

In order to remove such dry spots, the method of spraying the washing water onto the dust collecting plate generates a mist caused by the washing water spray, which acts as a conductor between the discharge electrode and the dust collecting electrode, causing a spark-over phenomenon that destroys the electric field. do. When the wet electrostatic precipitator is operated, a sparkover phenomenon may cause a reduction in dust collection efficiency, and thus, blue haze may be generated during the discharge of the rear end of the pollution prevention facility. In order to prevent such a sparkover phenomenon it is necessary to reduce the applied voltage or stop the application of high voltage during the spraying of the cleaning water, which causes a problem of lowering the efficiency of the wet electrostatic precipitator and guaranteeing continuous operation. In addition, the problem of the corrosion of the dust collector plate due to the attachment of acidic particles in the wet electrostatic precipitator is an important disadvantage in the general wet electrostatic precipitator with discontinuous operation.

An object of the present invention was devised to solve the above problems, and an object of the present invention is to provide a wet precipitator dust collecting plate uniform water film maintenance technology that can control the water supply amount and adjust the thickness of the cleaning water film.

In order to achieve the above object, the present invention includes a washing water amount adjusting device and a washing water film thickness adjusting device, the washing water amount adjusting device includes a control panel, and further comprises an electric field generating device for generating an electric field in the washing water flowing between the control panel and the dust collecting plate. Include. The washing water film thickness adjusting apparatus includes a current supply device for flowing a DC current to the washing water supplied from the washing water supply unit. The apparatus may further include an acid coating agent supply unit for supplying the acid coating agent together with the supply of the washing water.

According to the uniform water film maintenance technology of the wet electrostatic precipitator including the cleaning water amount adjusting device and the cleaning water film thickness adjusting device according to the present invention,

As well as maintaining a uniform water film, the thickness of the water film can be freely adjusted as necessary to increase the efficiency of the wet electrostatic precipitator and to suppress the occurrence of dry spots and blue haze. In addition, it is economical because it can produce a relatively low-cost wet electrostatic precipitator without using a high-cost corrosion-resistant material.

Hereinafter, the same reference numerals will be described in detail with reference to the accompanying drawings with reference to the same components preferred embodiments of the present invention. The terms or words used in the specification and claims are not to be construed as being limited to conventional or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical matters of the present invention.

1 is a conceptual diagram showing the configuration of the internal structure of a wet electrostatic precipitator according to an embodiment of the present invention. Referring to FIG. 1, a unit dust collecting unit includes a plurality of unit dust collecting units including a dust collecting plate 100 and a washing water supply unit 300, and a plurality of discharge plates 200. The dust is attached to the dust collecting plate 100 by an electric field formed between the discharge plate 200 and the dust collecting plate 100, and the dust collected on the dust collecting plate 100 is cleaned by the washing water supply unit 300. Is removed by numbers. 1 shows a wet electrostatic precipitator having three unit dust collectors as an embodiment of the present invention.

2 is a conceptual diagram illustrating a configuration of a unit dust collector of a wet electrostatic precipitator according to an embodiment of the present invention. 2, the unit dust collecting unit includes a washing water supply unit 300, a washing water amount adjusting device 310, a dust collecting plate 100, and a washing water film thickness adjusting device 120.

The washing water supply unit 300 generates a smooth washing water film at the start of the dust collector and stores and supplies a predetermined amount of the washing water in preparation for the change of the washing water quantity.

The washing water amount adjusting device 310 includes a control panel 320 capable of adjusting the opening degree between the dust collecting plate 100 and the washing water supplying part 300.

The control blade 320 is installed at intervals on both sides of the dust collecting plate 100 at the bottom of the washing water supply unit 300. When the washing water filled in the washing water supply unit 300 is adjusted to the thickness of the washing water when it is spread to the dust collecting plate 100, an appropriate amount of washing water is supplied to the surface of the dust collecting plate 100. Control panel 320 may include a cylinder type actuator (Cylinder Type Actuator) 325 and the cylindrical actuator 325 may be configured to automatically adjust the opening degree according to the amount of contaminants.

In addition, the control panel 320 may include an electric field generating device 330, which is scattered between the control panel 320 and the dust collecting plate when the amount of the washing water is adjusted by adjusting the surface tension of the washing water by the electric field. It can prevent possible droplets and allow the quantity to be adjusted. The electric field generator 330 is interlocked with the control panel 320. When the control panel 320 is automatically opened due to a large amount of pollutants, the electric field generator 330 may be configured to operate accordingly.

The washing water supply unit 300 may include a partition wall 340 provided in a zigzag form. The partition wall 340 allows the washing water to absorb the external shock or the shock caused by the rapid change in the quantity of water, thereby controlling the desired quantity of water. The configuration of the partition wall 340 is shown in detail in FIG. 4.

The washing film thickness control device 120 is composed of a current supply device. By controlling the thickness of the washing water film using the principle of electrodeposition coating, the washing water is uniformly flowed to the surface of the dust collecting plate 100 through the washing water supply unit 300 located on the upper surface of the dust collecting plate 100 and then the dust collecting plate 100 and When a DC current flows through the washing water film thickness adjusting device 120 between the discharge plate (not shown), the following four phenomena occur simultaneously, and the entire surface of the dust collecting plate 100 is uniform. A water film is formed. At this time, it is possible to easily adjust the water film thickness of the washing water by adjusting the amount of current applied.

(1) Electrolysis

When a direct current flows in the washing water solution spread on the surface of the dust collecting plate 100, chemical decomposition occurs by discharging between the positive electrode and the negative electrode, respectively, and release ions from the positive electrode and the negative electrode, respectively.

(2) Electrophoresis

When the electric field is applied to the washing water particles dispersed in the colloidal state in the washing water solution, the washing water particles in the colloidal state have a charge by dissociation of the dispersoid, adsorption of hot, and so on, and move toward the electrode having the opposite charge.

(3) Electro-deposition

The washing water particles moved to the positive electrode and the negative electrode react with each other to precipitate in a molecular state on the surface of the dust collecting plate 100 to form an electrodeposited water film.

(4) Electro-osmosis

The deposited electrodeposited membrane acts as a porous plate to separate the water. When the electrode is provided on both sides of the separated electrodeposited membrane to give a potential difference, the water moves through the electrodeposited membrane by the potential difference. Therefore, the height between the two liquid levels is different. The cation is more easily passed through the porous plate than the anion. Dehydration occurs due to electroinfiltration of water through the electrodeposition membrane.

Among the above four phenomena, electrolysis and electrophoresis are mainly related to the movement of the washing water particles in the vicinity of the electrode, and electroprecipitation and electropenetration are mainly related to adhesion on the surface of the dust collecting plate 100.

3 is a conceptual diagram showing an acid resistant film supply unit according to an embodiment of the present invention. Referring to FIG. 3, the washing water supply unit 300 further includes an acid coating agent supply unit 30. Corrosion problem of the dust collecting plate 100 due to the attachment of acidic particles in the wet electrostatic precipitator is another important disadvantage in the general wet electrostatic precipitator with discontinuous operation. In order to overcome this problem, the acid-resistant coating part 30 is periodically supplied to the washing water supply part 300 of the washing water amount adjusting device, and thus the acid-resistant coating is periodically performed.

The acid resistant film supply unit 30 includes an acid resistant storage and stirring device 32 and the supply pipe 31. Regarding the acid resistant film supplied by the acid resistant film supply unit 30, the principle of electrodeposition coating may be used in which the cleaning film thickness adjusting device spreads the washing water evenly on the surface of the dust collecting plate 100.

While the preferred embodiments of the present invention have been shown and described, it is not limited to the specific embodiments described above, and it is common in the art to which the present invention pertains without departing from the spirit of the invention as claimed in the claims. Many modifications are possible to those skilled in the art. In addition, matters that can be easily inferred from the accompanying drawings are to be regarded as included in the contents of the present invention even if they are not described in the detailed description, and various modifications may be separately understood from the technical spirit or the prospect of the present invention. Will not be.

1 is a conceptual view showing the configuration of the internal configuration of a wet electrostatic precipitator according to an embodiment of the present invention,

2 is a conceptual view showing the configuration of a unit dust collector of the wet electrostatic precipitator according to an embodiment of the present invention;

3 is a conceptual view showing an acid resistant film supply unit according to an embodiment of the present invention, and

4 is a conceptual diagram illustrating a configuration of a partition wall according to an embodiment of the present invention.

Claims (7)

In the wet electrostatic precipitator including a dust collecting plate, a discharge plate, and a washing water supply unit, A washing water amount adjusting device for adjusting a water supply amount of washing water supplied to the dust collecting plate; And And a washing water film thickness adjusting device for adjusting the thickness of the washing water film formed by the washing water supplied to the dust collecting plate. The washing film thickness control device is a wet electrostatic precipitator dust collecting plate uniform water film holding system, characterized in that it comprises a current supply device for flowing a direct current to the cleaning water supplied to the dust collecting plate. According to claim 1, wherein the amount of washing water control device includes a control panel installed in parallel with the dust collecting plate at the bottom of the washing water supply unit, the control panel is installed so as to be movable to adjust the gap with the dust collecting plate Wet Electrostatic Precipitator Dust Collector Uniform Water Retaining System. 3. The wet electrostatic precipitator dust collecting plate uniform water film maintaining system according to claim 2, wherein the control panel automatically adjusts a distance from the dust collecting plate according to the accumulation amount of pollutants. The wet electrostatic precipitator dust collecting plate uniform water film holding system of claim 2, wherein the washing water amount adjusting device further comprises an electric field generating device connected to the control panel to form an electric field in the washing water flowing between the control panel and the dust collecting plate. . delete The wet electrostatic precipitator dust collecting plate uniform water film holding system according to claim 1, wherein the washing water supply unit installs a partition wall in a zigzag form. The wet electrostatic precipitator dust collector plate as claimed in any one of claims 1 to 4 and 6, wherein the washing water supply unit further includes an acid coating agent supply unit for supplying the acid resistant coating agent together with the supply of the washing water. Water film maintenance system.

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