KR20010047773A - Apparatus for purifying wastewater using plasma - Google Patents

Abstract

PURPOSE: Provided is a wastewater treatment apparatus using plasma to remove organics and inorganic matters. CONSTITUTION: The apparatus consists of a pipe type dielectric (21) having an inlet (21a) for inhaling outer air and an outlet (21b) for exhausting internal air, an outer electrode (23) plated on the outside of the dielectric (21), an internal electrode (25), a coil spring installed along the dielectric (21) in the longitudinal direction, a power supplying device (30) for applying high-frequency/low voltage power between inner electrode and outer electrode so that plasma is generated at the inside of dielectric (21), a horse for supplying plasma into the wastewater.

Description

Apparatus for purifying wastewater using plasma}

The present invention relates to a wastewater purification apparatus, and more particularly, to an apparatus for purifying wastewater by supplying low temperature plasma generated in the plasma generator to the wastewater.

In the atmosphere, nitrogen and oxygen exist in the form of molecules. When electrical arc is applied to this molecular material, the molecules are separated into their respective ionic states, plus and minus ions. The material in the state of being ionized with positive and negative ions as described above is called plasma.

The plasma is divided into a high temperature plasma and a low temperature plasma. The high temperature plasma has a high temperature of about 15,000 to 20,000 K. This high temperature plasma is used to melt and cut the iron plate. Typically copper or aluminum is not oxidized and thus cut using plasma. Low temperature plasma has a strong energy to forcibly break the molecular rings of organic or inorganic substances in water. By the way, although the high temperature plasma is applied as mentioned above, the low temperature plasma is not actually used industrially.

It is an object of the present invention to provide a wastewater purification apparatus for purifying wastewater using the properties of such low-temperature plasma.

1 is a schematic diagram of a plasma generator used in the wastewater purification apparatus according to the present invention,

2 is a block diagram of the power generator of FIG.

3 is a view showing a state of use of the waste water purification apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

20: discharge tube 21: dielectric

23: external electrode 25: internal electrode

30: power supply 40: hose

45: diffuser 50: wastewater

Waste water purification apparatus according to the present invention for achieving the above object, the pipe-shaped dielectric having an inlet opening for the outside air flows in and the outlet opening the air inside thereof; An external electrode plated on an outer surface of the dielectric; An internal electrode of a coil spring shape disposed in the dielectric along the longitudinal direction thereof; A power supply device for generating a plasma in the dielectric by applying a high frequency low voltage power source between the external electrode and the internal electrode; And a hose coupled to the outlet opening of the dielectric to supply plasma discharged through the outlet opening into the wastewater.

Here, the voltage generated by the power supply is preferably an effective value of about 3000 volts and a frequency of 20 to 50 kHz.

According to the present invention, since the wastewater is purified using plasma, a wastewater purification apparatus having a very simple structure is provided.

Preferably, an air dispersing means for dissipating the plasma supplied into the wastewater through the hose is provided at the end of the hose. According to this, the amount of wastewater in contact with the plasma is increased, and the purification efficiency of the wastewater is further increased.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

The wastewater purification apparatus according to the present invention comprises a plasma generator for generating plasma and a plasma supply device for purifying the wastewater by supplying the plasma to the wastewater.

As shown in FIG. 1, the plasma generator includes a discharge tube 20 and a power supply device 30. The discharge tube 20 is composed of a dielectric 21, an external electrode 23, and an internal electrode 25.

Dielectric 21 is made of fine ceramic finely refined and has a pipe shape. Fine ceramics are obtained by thoroughly degreasing purified alumina and kneading and firing sufficiently at 1500 degrees Celsius or more. Since the volume is reduced during firing, the size of the mold should be determined in consideration of this. Inflow openings 21a and outflow openings 21b are formed at both ends of the dielectric 21, respectively. The outside air flows into the dielectric 21 through the inlet opening 21a, and the air inside the dielectric 21 flows out through the outlet opening 21b.

The external electrode 23 is formed by plating a metal on the outer surface of the dielectric 21. Since the external electrode 23 is used to apply an electric charge to the dielectric 21, the material may be any conductor, but is preferably made of copper or silver.

The internal electrode 25 has the shape of a coil spring disposed in the dielectric 21 along its longitudinal direction. The internal electrode 25 preferably uses an oxidation resistant material such as zirconium or stainless steel. As will be described later, some of the plasma may be changed to ozone while the plasma passes through the dielectric 21, because the ozone oxidizes the internal electrode 25 and eventually the internal electrode 25 disappears.

The power supply device 30 supplies a high frequency low voltage current between the external electrode 23 and the internal electrode 25. When power is supplied by the power supply device 30 and air or oxygen, which is carrier gas, is introduced into the dielectric body 21 through the inlet opening 21a, air or oxygen passes through the dielectric body 21 while causing high frequency arcing. It turns into plasma by the energy of corona generated by

In detail, when the positive voltage is applied to the external electrode 23, the outer surface of the dielectric 21 is negatively charged and the inner surface of the dielectric 21 is positively charged. At this time, since a negative voltage is applied to the internal electrode 25, a strong corona arc is generated between the dielectric 21 and the internal electrode 25. The corona arc is evenly distributed on the outer circumferential surface of the inner coil 25 of the coil spring shape, and the carrier gas is converted into plasma by the corona arc. When air or oxygen, which is carrier gas, is supplied into the dielectric 21, the carrier gas turns into a vortex while rotating around the inner electrode 25, so that the plasma rotates along the inner wall surface of the dielectric 21 to discharge the outlet 21b. Through the outflow to the outside of the dielectric 21.

2 shows a detailed configuration of the power supply device 30 shown in FIG. The power supply device 30 increases the voltage of the current generated by the rectifier circuit 31, the oscillator circuit 33 for generating a high frequency current, and the oscillator circuit 33 for converting a 60 Hz commercial AC power into a direct current. It includes a high pressure transformer 37 for.

Between the rectifier circuit 31 and the oscillation circuit 33, a frequency comparison channel 32 is provided. The frequency comparison channel 32 stabilizes the oscillation frequency of the oscillation circuit 33 by the voltage difference by receiving a part of power of the high voltage transformer 37 and phase discriminating. In practice, the oscillation frequency tends to be disturbed when the carrier gas passes inside the discharge tube 20. When the oscillation frequency is changed, the current state of high voltage is changed, so the feedback circuit is adopted to prevent this, and this feedback circuit can get very good results when the television's AFC (Automatic Frequency Control) circuit is applied. Can be.

The voltage oscillated by the oscillation circuit 33 is supplied to the coupling transformer 35 via the amplification circuit 34. The high frequency induced in the secondary coil of the coupling transformer 35 is supplied to the high voltage transformer 37 via a switching circuit 36 composed of a FET device or a transistor device. The voltage generated from the secondary coil of the high voltage transformer 37 is supplied to the discharge tube 20.

The voltage generated by the power supply 30 preferably has an effective value of about 3000 volts and a frequency of 20 to 50 kHz. At these voltages and frequencies, plasma is most effectively generated. In addition, although the waveform of the voltage can use both a sine wave and a square wave, the use of the square wave is higher plasma generation efficiency. On the other hand, the power supply device 30 does not interfere with the operation of the plasma generating device as long as it is an inverter that generates a high frequency in addition to the device having the above configuration.

On the other hand, the most important thing in manufacturing a low temperature plasma generator is that the length of the dielectric 21 should be short. If the length of the dielectric 21 is long, ions of oxygen changed into plasma form tend to turn into ozone while passing through the long dielectric 21, so it is essential to select the length of the dielectric 21 that does not turn into ozone. The appropriate length of the dielectric 21 is determined experimentally, and greatly depends on the frequency of the power generated by the power generator 30 and the dielectric constant of the ceramic constituting the dielectric 21. On the other hand, since ozone generated in addition to the plasma is a strong oxidizing gas, it can perform a function of purifying waste water. However, since plasma is much more efficient at purifying wastewater than ozone, it is desirable to generate more plasma than ozone as described above.

Also, do not use a higher voltage than necessary to generate strong corona. This is because a heat sink (not shown) made of aluminum or the like is usually used to cool the external electrodes 23, so that a load required to radiate heat is increased when a high voltage is applied. Preferably, the energy of the high frequency power source is determined so that the temperature of the dielectric 21 does not exceed 50 degrees to 60 degrees Celsius when the plasma generator is operated.

The plasma supply device is composed of a hose 40 and an air diffuser 45. The hose 40 is coupled to the outlet opening 21b of the dielectric 21 as shown in FIG. The hose 40 is immersed in the wastewater 50, and thus the plasma flowing out through the outlet opening 21b is supplied into the wastewater 50. The plasma supplied to the wastewater 50 decomposes organic and inorganic substances in the wastewater 50 as described above, and thus the wastewater 50 is purified.

An air diffuser 45 is provided at the end of the hose 40. The air diffuser 45 diffuses the plasma supplied into the wastewater through the hose 40 to generate bubbles B. As a result, the plasma comes into contact with a larger amount of wastewater 50, and the purification efficiency of the wastewater 50 is further increased. As the diffuser device 45, an diffuser used in a general fish tank or the like may be used, and an aerator stone or an injector may be used.

On the other hand, in order to prevent foreign matter from entering the discharge tube 20, the carrier gas which moves and generates plasma should be very clean. Therefore, it must be pre-purified using a multistage air filter, and the specification of the filter used should be 0.01 micron or less. In addition, in order to prevent the penetration of moisture into the discharge tube 20, the carrier gas must be dehumidified by a cooling device.

As described above, according to the present invention, as the low-temperature plasma is supplied into the wastewater 50, the organic and inorganic substances in the wastewater 50 are decomposed to purify the wastewater 50. Accordingly, a wastewater purification apparatus capable of easily purifying wastewater 50 using a plasma generator having a simple structure is provided.

Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific preferred embodiments described above, and the present invention is not limited to the specific scope of the present invention as claimed in the claims. Anyone of ordinary skill in the art can make various modifications, as well as such modifications are within the scope of the claims.

Claims (3)

In the wastewater purification device, A pipe-shaped dielectric having an inlet opening through which outside air flows in and an outlet opening through which air inside thereof flows out; An external electrode plated on an outer surface of the dielectric; An internal electrode of a coil spring shape disposed in the dielectric along the longitudinal direction thereof; A power supply device for generating a plasma in the dielectric by applying a high frequency low voltage power source between the external electrode and the internal electrode; And And a hose coupled to the outlet opening of the dielectric and supplying plasma discharged through the outlet opening into the wastewater. The method of claim 1, The voltage generated by the power supply is wastewater purification apparatus, characterized in that the effective value is about 3000 volts and the frequency is 20 to 50kHz. The method of claim 1, And an air dispersing means installed at an end of the hose to diffuse the plasma supplied into the waste water through the hose.