JPS592846Y2 - electrostatic precipitator - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of an electrostatic precipitator that uses spray fluid to clean the dust attached to the dust collecting electrode plate. By cleaning the dust collecting plate at the same time as the dust collecting electrode plate, the insulation resistance of the insulator is prevented from decreasing.

Electrostatic precipitators are used to remove mist from various exhaust gases.

This exhaust gas includes some that contain oil and tar, and some that does not.

For electrostatic precipitators that handle exhaust gas that does not contain oil or tar, it is only necessary to wash the dust collector plate with pure water, but for electric precipitators that handle exhaust gas that contains oil or tar, it is sufficient to wash the dust collecting plate with pure water. Dusters need to be cleaned with an alkaline solution such as a caustic soda solution.

Although cleaning with an alkaline solution improves the cleaning effect, it also brings with it some disadvantages.

Among electrostatic precipitators, for example, in an electrostatic precipitator that collects tar mist such as smoke exhaust gas from ham, sausage, etc., highly viscous tar adheres to the dust collecting electrode plate.

The exhaust gas in this case is usually produced by smoking wood chips, so its main component is a tar mist, and some of it contains steam added to smoke the meat. ing.

Therefore, water droplets with low viscosity and tar-like dust with high viscosity are collected on the dust collecting electrode plate.

Water droplets with low viscosity flow and fall on the dust collecting electrode plate, but tar particles with high viscosity adhere to the dust collecting electrode plate.

An alkaline solution such as a 1% caustic soda solution is suitable for cleaning the attached tar.

FIG. 1 shows an example of an electrostatic precipitator for collecting such tar mist.

To explain this, 1 is a main body, and a suction port 2 is provided at the bottom of the main body, and an exhaust port 3 is provided at the top.

A charging section unit 4 and a dust collecting section unit 5 are housed in a stacked state approximately in the center inside the main body 1, and a fan 6 is provided in the -1 part.

As a result, the exhaust gas that has entered the interior of the main body 1 through the suction port 2 passes through the charging unit 4 and the dust collection unit 5 due to the suction force of the fan 6, and is discharged to the outside through the exhaust port 3.

During this process, the dust is charged by the charging unit 4, and part of the dust is collected there, and the rest is collected by the dust collecting unit 5.

A dust collecting electrode plate cleaning nozzle 7.8 is provided at the bottom of the charging unit 4 and at the top of the dust collecting unit 5, and sprays a cleaning liquid onto the charging unit 4 and the dust collecting unit 5. It looks like this.

This spraying is performed when a certain amount of dust is collected and deposited on the dust collection electrode plates of the charging unit units 1 to 4 and the dust collection unit 5, and then an alkaline solution is first injected to dissolve the tar on the dust collection electrode plates. , followed by water spraying and cleaning.

FIG. 2 shows the charging section unit 4, and FIG. 3 shows the dust collecting section unit 5.

To explain this, the charging section unit 4 has a plurality of ground electrode plates 10 between the insulator chambers 9, 9 provided oppositely.
It is attached by a ground stud 11.

Purge holes 12.13 are provided in the insulator chamber 9 and the ground electrode plate 10, through which a high-voltage stud 15 supported by a high-pressure channel 14 passes.

There is an air gap between the high pressure studs 15 and 15 provided oppositely.
Electric wire 16 is stretched.

The high voltage channel 14 is insulated by an insulator 17,
It is attached to the insulator chamber 9.

The dust collecting section unit 5 has almost the same structure, but in this case it is larger than the charging section unit 4, and a high voltage electrode plate 18 is provided between the insulator chamber 9 and the ground electrode plate 10. are different.

When both the charging section unit 4 and the dust collecting section unit 5 are in use, a high voltage is applied to each discharge wire 16 and high voltage plate 18 via the high voltage channel 14 and the high voltage stud 15.

For this reason, a purge hole 12 is essential in the insulator chamber 9.

Conventional electrostatic precipitators with this type of structure, during dust collection operation,
Particles of exhaust gas flowing inside the main body 1, mist water droplets, alkaline solution, etc. during cleaning work flow from the purge hole 12 to the insulator chamber 9.
There is a problem in that the particles get inside the insulator 17, staining it, and lowering the insulation resistance of the insulator 17.

Conventionally, therefore, outside air is blown into the interior of the main body 1 to create an air current (purge air) that always flows inward through the purge holes 12 to prevent exhaust gas particles and droplets from entering the insulator chamber 9. was carried out.

FIG. 4 shows an example of such a device.

To explain this, in this case, the outside air intake port 19 of the main body 1
is provided, and outside air is sucked into the main body 1 through a filter 20 attached thereto.

A purge nozzle 22 is provided on the lid 21 of the insulator chamber 9 so that outside air enters the insulator chamber 9 and flows from the purge hole 12 toward the charging section unit 4 and the dust collecting section unit 5.

This airflow prevents exhaust gas particles and droplets from entering the insulator chamber 9.

Although this prevented exhaust gas particles from entering the insulator chamber 9 during steady operation, the internal pressure of the charging section unit 4 and the dust collecting section unit 5 increased when spraying was performed to clean the dust collecting electrode plate. However, this weakens the purge air, causing the alkaline solution to enter the insulator chamber 9 or causing the alkali solution leaking to the front of the insulator chamber 9 to be stirred up in the form of mist, thereby preventing alkali contamination of the insulator 17. There was a problem that could not be completely prevented.

When the insulator 17 is contaminated with alkali, since alkali is a hygroscopic substance, it adsorbs moisture in the atmosphere and becomes an electrolyte, lowering the insulation resistance of the insulator 17 and preventing it from being applied to the discharge wire 16 or high-voltage plate 18. There is a problem in that this prevents the application of high pressure and eventually stops the dust collection function.

This idea was made in view of this point, and water is sprayed into the insulator chamber 9 at the same time when cleaning the dust collecting electrode plate, thereby eliminating the internal pressure difference between the insulator chamber 9, the charging section unit 4, and the dust collecting section unit 5. In this way, the amount of alkaline solution entering the insulator chamber 9 is reduced as much as possible, and even if the alkaline solution enters the insulator chamber 9 and adheres to the insulator 17, it is removed by the sprayed water. It was also designed to be washed away.

An embodiment of this invention will be explained with reference to FIG. 5. In this case, when a certain amount of dust is collected and deposited on the dust collecting electrode plates of the charging unit 4 and the dust collecting unit 5, an alkaline solution is injected. The insulator chamber cleaning nozzle 23 operates simultaneously with the dust collecting electrode plate cleaning nozzle 7 and 8 which dissolves tar on the dust collecting electrode plate and subsequently sprays water into the insulator chamber 9.
is arranged between the charging section unit 4 and the dust collecting section unit 5.

As a result, when the charging section unit 4 and the dust collecting section unit 5 are injecting alkaline solution and water from the dust collecting electrode plate cleaning nozzle 7.8, the insulator chamber 9 is simultaneously cleaned by the insulator chamber cleaning nozzle 23. ing.

FIG. 6 shows another embodiment of this invention.

In this case, a dust collecting electrode plate cleaning nozzle 7 that sprays alkaline solution and water onto the charging unit 4 and the dust collecting unit 5 is used.
．． An insulator chamber cleaning nozzle 23 that operates at the same time as 8 and only sprays water into the insulator chamber 9 is disposed further outside the insulator chamber 9 provided outside the charging section unit 4 and the dust collecting section unit 5. The dust collecting unit 4 and the dust collecting unit 5 are cleaned through the insulator chamber 9.

In both of these embodiments, water is sprayed into the insulator chamber 9 at the same time as the alkaline solution spray and water spray from the charging section unit 4 and the dust collecting section unit 5. There is no pressure difference between the two, and no alkaline solution enters the insulator chamber 9.

Even if the alkaline solution adheres to the surface of the insulator 17, the spray water will wash it away.

FIG. 7 shows the drying characteristics of the insulator due to Joule heat.

This is a comparison diagram using three types of insulators.

Of these, A is one that has been pickled in tap water, B is one that has been mashed in 1% caustic soda solution, and C is one that has been soaked in 1% caustic soda solution and then taken out and washed with tap water. .

These insulators are placed in a box filled with mist, and the recovery characteristics of the insulation resistance on the surface of the insulators are shown when a DC high voltage of 12 KV is continuously applied.

The following can be seen from this figure.

In other words, the insulator A has a low resistance value immediately after voltage application because it is only wet with water, but the insulation is restored in a short time by Joule heating caused by the leakage current. is attached to the insulator surface, so even if it is dried by Joule heat, the alkaline content on the insulator surface will absorb moisture again, and the surface resistance recovery characteristics will tend to become saturated.

In the insulator C, most of the alkaline solution was washed away with water, so the insulator surface resistance gradually recovered.

From these facts, it can be seen that even if an alkaline solution gets on the surface of an insulator, if it is immediately washed away with water, a decrease in the surface resistance of the insulator can be prevented.

For this reason, this invention has the advantage of being able to prevent the insulation resistance of the insulator from decreasing.

In addition, this device has the advantage that it can exhibit the same effect even when the insulator is contaminated with acid due to causes other than alkaline solutions, such as when cleaning dust containing sulfuric acid mist with water spray. be.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view schematically showing an example of a conventional electrostatic precipitator;
FIG. 2 is a perspective view showing the charging unit of FIG. 1;
Figure 3 is a perspective view showing the dust collection unit of Figure 1;
Fig. 4 is a partially cutaway view schematically showing another example of a conventional electrostatic precipitator, Fig. 5 is a sectional view schematically showing an embodiment of this invention, and Fig. 6 is another embodiment of this invention. A cross-sectional diagram schematically showing an example,
FIG. 7 is a graph showing the drying characteristics of an insulator due to Joule heat. 1: Main body, 2: Suction port, 3: Exhaust port, 4: Charging section unit, 5: Dust collection section unit, 6: Fan, 7, 8, 23
: Dust collection electrode plate cleaning nozzle, 9: Insulator chamber, 23: Insulator chamber cleaning nozzle.

Claims (3)

[Scope of utility model registration request] (1) A dust collecting electrode plate cleaning nozzle that cleans the collecting electrode plate by spraying an alkaline solution and water in an electric precipitator capable of cleaning tar dust attached to the collecting electrode plate by spraying an alkaline solution. is arranged near the dust collecting electrode plate, an insulator chamber cleaning nozzle for cleaning the hardness chamber by jetting water is arranged near the insulator chamber, and both cleaning nozzles are operated simultaneously. Electric precipitator. (2) Utility Model Registration The electrostatic precipitator according to claim 1, characterized in that an insulator chamber cleaning nozzle is disposed between a charging unit and a dust collecting unit. (3) Scope of Utility Model Registration In the electrostatic precipitator described in claim 1, the insulator chamber cleaning nozzle is disposed further outside the insulator chambers provided outside each of the charging section unit and the dust collecting section unit. An electric precipitator featuring: