KR19990041595A - Plasma reactor - Google Patents

Abstract

The present invention relates to a plasma reactor for removing contaminants in wastewater or contaminated air by plasma, and includes a housing acting as a main body and upper and lower portions of a conductor installed inside the housing to which power is applied. A ring and an intermediate ring, an insulator installed between the housing and the ring to insulate them, a power supply electrode fixed to each ring, and a steel ball fixed at both ends thereof perpendicularly to the power supply electrode of the intermediate ring. A plurality of first electrodes and a plurality of second and third electrodes fixed vertically to the power supply electrodes of the upper and lower rings, respectively, positioned between the first electrodes and having steel balls fixed at one end thereof. Eliminates losses, difficulty in large-scaled, and incomplete pollution treatment.

Description

Plasma reactor

The present invention relates to a plasma reactor for removing contaminants in wastewater or contaminated air by plasma, and more particularly, to a plasma reactor in which corona discharge occurs as a pulse generated from a generator is supplied.

Today, interest in the living environment is increasing day by day, and efforts are being made to keep clean air and clean water.

The environmental industry is divided into four categories: air pollution prevention, water pollution prevention, waste treatment, and clean technology.

In the air and water pollution prevention field, a process applied to the treatment of pollutants contained in air or wastewater or the production of tap water has been researched and developed by many scholars.

However, the development of efficient and economical processes and equipment is still not made in many areas.

In general, we lowered the BOD by removing organic substances (mainly hydrocarbons) contained in the wastewater, and discharged the treated wastewater to the river in consideration of the completion of the wastewater treatment.

However, due to the development of industry and the urban concentration of the population, pollutants of various characteristics are released which were not predicted before, but the toxicity and environmental impact of these pollutants are not properly evaluated and the polluted air and wastewater are treated. .

For example, chlorine, which we often use for water disinfection, has recently been known to form a carcinogen, TMS, which is confirmed by epidemiological investigations of residents who consumed chlorinated tap water for long periods of time. It became.

In addition, the increase of domestic sewage due to population concentration has a large amount of nitrogen (N) and phosphorus (P) components in discharged sewage, which acts as a direct cause of eutrophication of rivers, lakes, and estuaries. Red tide phenomenon appeared.

As the water quality is eutrophic, the breeding of algae, which eats nutrients, increases rapidly, and the rivers and lakes, etc., completely destroy ecosystems due to oxygen depletion.

Therefore, contaminated air or wastewater has to be purified by various methods.

Among the above methods, wastewater treatment methods include physicochemical treatment, biological treatment, flocculation treatment, Fenton oxidation method, ozone treatment, electron beam treatment, activated carbon adsorption treatment, membrane separation treatment and full plasma treatment. Known.

In recent years, various types of contaminants contained in wastewater or polluted air are removed by using plasma capable of simultaneously treating sulfur dioxide and nitrogen dioxide in exhaust gas, which is a major cause of hardly degradable wastewater or air pollution.

1A and 1B are principal parts perspective views and longitudinal cross-sectional views showing a plasma reactor of the prior art, and FIGS. 2A and 2B are views showing a state where corona discharge occurs in a conventional plasma reactor.

The technology for treating contaminants contained in contaminated air and wastewater using the plasma is largely generated by a generator (not shown), which is a power supply that generates pulses and supplies them to the reactor, and generates a corona discharge to react with the contaminants. It is composed of a reactor (1) to raise the contaminants.

The reactor 1 is composed of a box-shaped housing 2 as shown in FIG. 1A and an electrode 3 mounted in a wire form in the box-shaped housing 2, or as shown in FIG. 1B. (4) and a needle-shaped electrode (5) mounted inside the cylindrical housing (4).

The generator (not shown) generates a pulse having a width of several hundred nanoseconds in a high voltage and high current state, and serves to supply the electrodes 3 and 5 in the housing 2 and 4.

Accordingly, when corona discharge occurs in the electrodes 3 and 5 located in the housing 2 and 4 as shown in FIGS. 2A and 2B, air particles located around the streamer caused by the corona discharge are ionized. The plasma state is changed.

In the plasma state, since gaseous substances easily cause chemical changes, various contaminants harmful to the human body are converted into harmless substances through chemical reactions.

Plasma equipment that removes contaminants by this structure and principle is also important for generator performance, but plasma generation efficiency and contamination depending on the shape and arrangement of electrodes 3 and 5 located in reactor 1 and causing corona discharge. Since the material removal efficiency is greatly left and right, the shape and arrangement of the electrodes are also very important.

The electrode for plasma generation according to the prior art includes a wire-shaped electrode 3 as shown in FIG. 1A, a needle-like electrode 5 as shown in FIG. 1B, or an electrode having a square rod bent in shape. The end 3a of the wire electrode 3 to which the pulse is applied is not located in the housing 2 in which the actual plasma reaction takes place, as shown in FIG. 2A, but is located outside.

In addition, the electrodes 3 installed in the housing 2 are simply arranged in the form of a wire-plate or a wire-cylinder as shown in FIG. 1A to add a positive (+) to the wire-shaped electrode 3 and to form a plate or cylinder. A negative (-) power is applied to the housing (2) or the power of the opposite pole is applied to induce the generation of plasma.

The plasma reactor 1 configured as described above removes contaminants by using a plasma formed in air or in water because a streamer corona is advanced from the electrode by a potential difference between the electrodes 3 and 5 and a plane. Done.

In this case, when the needle type electrode 5 as shown in FIG. 1B is used, the streamer corona is concentrated on the raised portion of the needle electrode 5, thereby effectively generating plasma.

Accordingly, the contaminants passing through the plasma generating region are chemically reacted by the active species formed by the plasma, and thus are converted into harmless materials or converted into materials that are easy to process and are removed.

However, such a conventional plasma reactor has the following problems.

First, when the wire-type electrode is used, the streamer corona is unevenly distributed between the electrode and the housing, so that the contaminants passing through the area cannot be completely treated.

Second, in the case of using a needle-type electrode for the concentration of the electric field, the treatment efficiency of the contaminants is increased while the cost of manufacturing the electrode is high, thus increasing the equipment cost.

Third, the spacing between the housing and the electrode is determined by the voltage applied, but its dimensions are limited (usually no more than 5 cm), so that multiple cells can be used to purify large amounts of contaminated air and wastewater. It was not easy to manufacture because it was necessary to manufacture reactors in the form of honey comb by connecting them in parallel and it is uneconomical because there are many problems in the insulation between cells.

Fourth, since the electrode end of the wire form is located outside the housing, a lot of power loss occurred.

That is, when the polarity of the pulse applied to the electrode is positive (+), the corona proceeds from the electrode toward the housing, but when the polarity is negative (-), the corona does not proceed toward the electrode from the wide side of the housing. Half of the applied power was not used properly.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to construct a large-capacity reactor using a combination of electrodes in the form of wires in a housing to facilitate plasma generation and to suppress generation of arcs during plasma generation.

1A and 1B are main parts perspective and longitudinal cross-sectional views showing a conventional plasma reactor.

2A and 2B are diagrams illustrating a state where corona discharge occurs in a conventional plasma reactor.

3 is a perspective view showing an embodiment of the present invention

Figure 4 is a detailed view showing the electrode applied to the present invention

5 is a plan view and a longitudinal sectional view showing another embodiment of the present invention.

6a to 6b is a distribution diagram of the streamer corona according to the change of polarity

Explanation of symbols for main parts of the drawings

6: housing 7a: upper ring

7b: lower ring 8: middle ring

10a, 10b: power supply electrode 11: steel ball

12: first electrode 13: second electrode

14: third electrode

Plasma reactor according to the present invention, the upper and lower rings and the intermediate ring of the housing that serves as the main body, the conductor is installed inside the housing to which the power is applied, and is installed between the housing and the ring and insulated between them An insulator, a power supply electrode fixed to each of the rings, a plurality of first electrodes fixed perpendicularly to the power supply electrode of the middle ring, and steel balls fixed at both ends thereof, and power supply electrodes of the upper and lower rings. Each of them is vertically fixed and positioned between the first electrodes, and consists of a plurality of second and third electrodes having steel balls fixed at one end thereof.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 3 to 6B, which illustrate one embodiment.

3 is a perspective view showing an embodiment of the present invention, Figure 4 is a detailed view showing the electrode applied to the present invention and Figures 6a to 6b is a distribution diagram of the streamer corona according to the change in polarity.

According to the present invention, the upper and lower rings 7a and 7b and the intermediate ring 8 of the conductor to which the power is applied are provided in the housing 6 by the insulator 9. It is installed to be insulated from each other.

In an embodiment of the present invention, the housing 6 is illustrated in a cylindrical shape, but the present invention is not necessarily limited to this, since the housing 6 may be applied in a box shape.

Power supply electrodes 10a and 10b are fixed to the upper and lower rings 7a and 7b and the intermediate ring 8, respectively, and steel balls are provided at both ends of the power supply electrode 10b of the intermediate ring 8, respectively. The plurality of first electrodes 12 having the ball 11 fixed thereto are fixed at right intervals at a predetermined interval, and at one end of the power applying electrode 10a of the upper and lower rings 7a and 7b. A plurality of second and third electrodes 13 and 14 having 11 fixed thereto are fixed to be positioned between the first electrodes 12.

The reason why the steel balls 11 are fixed to both ends of the first electrode 12 and one end of the second and third electrodes 13 and 14 is that when the end of the electrode is positioned inside the housing 6, the end of the electrode This is to prevent the plasma generated in the easy to proceed to the far arc than the plasma generated in the other part because it inhibits the plasma generation of other parts in advance.

More preferably, a plurality of power supply electrodes 10a and 10b fixed to the upper and lower rings 7a and 7b and the middle ring 8 are fixed in parallel.

This is because the positions of the first, second, and third electrodes 12, 13, and 14 that are fixed perpendicularly to the power applying electrodes 10a, 10b are more firmly fixed. This is to prevent the occurrence of short.

In addition, it is more preferable to form the outer circumferential surfaces of the first, second and third electrodes 12, 13 and 14 in the form of screws because the streamer corona in the housing is uniformly distributed than in the form of wires.

That is, when the outer circumferential surfaces of the first, second and third electrodes 12, 13 and 14 are in the form of screws, as shown in FIG. 4, streamer corona is formed at each end of the screw form, which is the entire region of the electrode. to be.

The first electrode 12 and the second and third electrodes 13 and 14 are fixed to the upper and lower rings 7a, 7b and the intermediate ring 8 so as to be arranged in a zigzag pattern.

This is to further increase the generation area of the streamer corona by sufficiently securing a gap with each electrode as shown in FIGS. 6A and 6B.

If each electrode is arranged in an in-line shape, there is a possibility that the space between them is insufficient, resulting in a reduction in the streamer generation area.

The arrangement interval of each electrode is determined by the intensity of the voltage supplied, and the length of each electrode is determined in proportion to the residence time of the contaminants in the housing.

In other words, if the applied voltage is strong, the distance between the electrodes should be set wide and, on the contrary, if the distance is set narrow, the same effect is obtained.If the time for which the contaminants stay in the housing 6 is short, the length of the electrode is set longer and vice versa. If the residence time is long, it may be set short.

As shown in FIG. 3, negative (−) power is connected to the upper and lower rings 7a and 7b to which the housing 6 is insulated by the insulator 9 and to which power is applied, and an intermediate ring ( 8) a positive power supply is connected.

However, as shown in FIGS. 6A and 6B, the positive and negative power are connected to the upper and lower rings 7a and 7b, and the negative and negative power are connected to the middle ring 8. The same effect occurs, so there is no need to limit the power applied to each ring.

On the other hand, when the reactor 1 of a large size is to be comprised, the number of electrodes installed in the housing 6 may be increased.

That is, as shown in FIG. 5 as another embodiment, a plurality of power applying electrodes 10a and 10b to which power is applied to each of the upper and lower rings 7a and 7b and the middle ring 8 are parallel and fixed in parallel. The first, second, and third electrodes 12, 13, and 14 are fixed to the power supply electrode in a vertical zigzag fashion as in the exemplary embodiment, whereby a large-capacity reactor can be configured.

Of course, steel balls 11 are fixed to both ends and one end of the first, second, and third electrodes 12, 13, and 14 fixed to the power applying electrodes 10a, 10b, respectively. The outer circumferential surfaces of the electrodes 12, 13 and 14 are made in the form of screws.

Referring to the operation of the present invention configured as described above is as follows.

When the pulse generated by the generator is applied to the power supply electrodes 10a and 10b fixed to the upper and lower rings 7a and 7b and the intermediate ring 8, respectively, the first, screwed, The electric field is concentrated over the entire outer circumferential surface of the 2, 3 electrodes 12, 13, 14, which generates a much better and more uniform plasma than the conventional one.

As such, when the electric field is concentrated on the outer circumferential surface of each electrode, the steel balls 11 fixed to both ends of the first electrode 12 and one end of the second and third electrodes 13 and 14 generate better plasma than other parts. It will increase the removal efficiency of the pollutant.

6A to 6B are diagrams showing the distribution of streamer corona generated around the electrode whenever the polarity of the pulse power source is changed, and a positive or negative polarity is applied to the intermediate ring 8. -) Even if the polarity is applied, the inside of the housing 6 is always filled with the streamer corona, which means that the air in the reactor is in a sufficient plasma state.

Therefore, it is understood that contaminants passing through the reactor are treated by a plasma that is uniformly distributed throughout.

As described above, the present invention has the following advantages.

First, since the same effect as when using a needle-type electrode using a wire-type electrode is reduced the cost according to the manufacturing of the reactor.

Second, since the same corona is possible regardless of the polarity of the power applied to the power applying electrode, the applied polarity is changed, thereby preventing the loss of input power.

Third, when constructing a large-capacity reactor, a large-capacity reactor can be configured by zigzag arrangement of a plurality of electrodes in a single housing without combining multiple cells as in the prior art, thereby reducing the cost of manufacturing.

Claims (10)

A housing acting as a main body, upper and lower rings and an intermediate ring of a conductor installed inside the housing to which power is applied, an insulator provided between the housing and the ring to insulate them from each other, A fixed power supply electrode, a plurality of first electrodes fixed perpendicularly to the power supply electrode of the intermediate ring and having steel balls fixed at both ends thereof, and vertically fixed to the power supply electrodes of the upper and lower rings, respectively; Plasma reactor which is located between, and composed of a plurality of second, third electrodes steel balls are fixed to one end thereof. The method of claim 1, A plasma reactor having an outer circumferential surface of the first, second and third electrodes having a screw shape. The method of claim 1, And the first electrode and the second and third electrodes are arranged in a zigzag pattern. The method of claim 1, And a plurality of power supply electrodes fixed to each ring. The method of claim 1, A negative (-) power is applied to the upper and lower rings, and a positive (+) power is applied to the middle ring. The method of claim 1, A positive (+) power is applied to the upper and lower rings, and a negative (-) power is applied to the middle ring. The method of claim 1, And a plurality of power applying electrodes fixed in parallel to the respective rings, and fixing the first, second and third electrodes to the power applying electrodes, respectively, so that the first, second and third electrodes are uniformly distributed in the housing. The method of claim 7, wherein A plasma reactor having an outer circumferential surface of the first, second and third electrodes having a screw shape. The method of claim 1, The arrangement interval of each electrode is determined according to the intensity of the voltage applied. The method of claim 1, Wherein the length of each electrode is determined in proportion to the residence time of the contaminants in the housing.