CN115259308A - Device and method for treating wastewater by atomizing plasma - Google Patents

Abstract

The invention discloses a device and a method for treating wastewater by atomized plasma, wherein the wastewater to be treated is atomized into uniform liquid drops by an atomization system on the upper part of the device and sprayed to a discharge plasma area on the lower part of the device; the atomized wastewater passes through a discharge plasma region and is directly contacted with plasma for treatment; the treated wastewater automatically enters a collecting device to be circularly treated. The invention adopts the method for treating the wastewater by the atomized plasma to separate the atomized area from the plasma area, the plasma characteristic is not influenced by the wastewater, and the method is suitable for treating the industrial wastewater with different components. The removal rate of COD of the industrial wastewater with different high concentrations after being treated by the method is higher than 99 percent.

Description

Device and method for treating wastewater with atomized plasma

technical field

The invention relates to the field of plasma technology for treating wastewater, in particular to a device and method for treating wastewater with atomized plasma.

Background technique

Water pollution has become an urgent problem in the world today. With the continuous development of my country's chemical, textile, printing and dyeing and pharmaceutical industries, the composition of wastewater is becoming more and more complex, and the amount of wastewater discharge is increasing, which has a serious impact on ecological balance and human health. Traditional biological treatment methods and physical and chemical treatment methods have been unable to solve the complex components in wastewater, and it is difficult to meet the purification and discharge standards of wastewater. Faced with this situation, plasma technology emerged as a zero-pollution, low-emission, environmentally friendly advanced oxidation technology. This technology uses high-voltage discharge to generate strong oxidizing free radicals, high-energy electrons, and atoms in an excited state. Molecules and other highly active particles can react with complex components in wastewater to crack macromolecular pollutants into small molecular safe substances. At the same time, the photothermal characteristics of plasma technology will promote the degradation of pollutants. carried out.

At present, different forms of discharge plasma technology have been applied to wastewater treatment, but there are problems such as small effective contact area between plasma and wastewater, low treatment efficiency, and limited types of applicable wastewater. "A Low-Temperature Plasma Water Treatment Device" disclosed in the domestic application number 201110191165.8 proposes to use the plasma generated by dielectric barrier discharge to treat wastewater with a depth of 5.0-10.0cm to reduce the concentration of pollutants contained in wastewater. However, the discharge The plasma area cannot completely cover the wastewater at a depth of 5.0-10.0cm, and the effect of the discharge plasma generated in this form to treat wastewater is limited by the conductivity of the wastewater.

Domestic application number 201610324278.3 discloses "an underwater pulse rotating sliding arc low-temperature plasma sewage treatment device" which proposes to use underwater sliding arc discharge plasma for sewage treatment. This method also has the characteristics of discharge plasma affected by the conductivity of wastewater. , applicable to limited types of wastewater. Therefore, it is imperative to develop a method that can efficiently treat multiple types of wastewater in large quantities.

Contents of the invention

The object of the present invention is to provide a device and method for treating wastewater with atomized plasma, which uses a power supply with high power output to stimulate plasma with high energy density, so that the atomized wastewater can pass through the discharge plasma area, improving The effective contact area between plasma and wastewater and the wastewater treatment capacity can meet the needs of different types of wastewater treatment and large-scale industrial applications.

In order to achieve the above purpose, the technical scheme adopted is as follows:

The specific method is:

A device for treating wastewater with atomized plasma, including an atomizing system, a device housing, and at least one set of sliding arc electrodes;

The atomization system includes an atomization nozzle and a nozzle fixing plate, the atomization nozzle is fixed on the nozzle fixing plate, and the nozzle fixing plate is located above the device housing;

From top to bottom in the device housing, there are atomization area and plasma area;

Each set of sliding arc electrodes includes two blades and an arc blowing pipe. The two blades are fixed on the fixed plate on the electrode side. There is a distance between the two blades, the distance is 1mm; connected to ground;

The arc blowing pipe is located between the two blades and installed at the center of the fixed plate on the electrode side. The front end of the arc blowing pipe is shorter than the bottom end of the blade, and the distance between the front end of the arc blowing pipe and the bottom end of the blade is 0.5mm;

Install the sliding arc electrodes respectively at the branch openings on the side of the plasma area of the device housing;

A water outlet is provided at the bottom of the device housing, and a collecting device is provided at the water outlet.

The fulcrum of the device housing is cylindrical and inclined, and the angle between the central axis and the vertical direction is 30-60°

The blade of the sliding arc electrode is a sliding arc blade, with a threaded rod at the end, which is installed on the fixed plate on the electrode side through threads;

There are multiple sets of threaded holes with different pitches on the fixed plate on the electrode side for installing threaded rods.

The method of treating wastewater with atomized plasma, the wastewater to be treated is atomized into uniform droplets through the atomization system on the upper part of the device, and sprayed to the plasma area at the lower part of the device; the atomized wastewater will all pass through the plasma area and directly contact with the plasma Contact for treatment; the treated wastewater automatically enters the collection device for recycling.

The flow rate of the atomized wastewater is not greater than 10L/min, the spraying distance is less than 1m, the spraying angle is not greater than 100°, and the diameter of the atomized droplets is less than 50μm.

The plasma region is generated by the sliding arc electrode (4), and the sliding arc electrode (4) is driven by a high-voltage AC power supply, the output voltage is not greater than 40kV, and the frequency is not higher than 25kHz.

Air, oxygen, nitrogen or their mixed gas with a flow rate of 1-10L/min is passed into the arc blowing pipe.

Compared with the prior art, the wastewater treatment method and device of the present invention have the following advantages:

The method and device for treating wastewater with atomized plasma provided by the present invention separate the atomizing system from the plasma area, and the characteristics of the plasma are not affected by the wastewater, and can be applied to the treatment of wastewater with different components;

The method and device for treating wastewater with atomized plasma provided by the present invention atomize the sewage and then pass through the plasma area for treatment. The sliding arc electrode is located directly under the atomizing nozzle, and all atomized wastewater can pass through the plasma area, effectively The contact area between sewage and plasma is greatly improved, and the treatment efficiency of sewage is improved.

The method and device for treating wastewater with atomized plasma provided by the invention are easy to operate, low in cost, and have a large amount of treated sewage, which can meet industrial needs.

The method and device for treating wastewater with atomized plasma provided by the present invention do not need to add chemical reagents and catalysts in the process of treating wastewater, do not generate secondary pollution, and are beneficial to environmental protection.

Description of drawings

Fig. 1 is a schematic structural diagram of a device for treating wastewater with atomized plasma according to the present invention.

In the figure: 1-atomizing nozzle, 2-nozzle fixing plate, 3-device shell, 4-sliding arc electrode, 5-arc blowing pipe, 6-electrode side fixing plate, 7-water outlet, 8-high voltage power supply , 9-branch, 10-collection device.

Detailed ways

Embodiments of the present invention will be specifically described below in conjunction with the accompanying drawings.

As shown in Figure 1, the device for treating wastewater with atomized plasma includes an atomizing system, a device housing 3, and at least one set of sliding arc electrodes 4;

The atomization system includes an atomization nozzle 1 and a nozzle fixing plate 2, the atomization nozzle 1 is fixed on the nozzle fixing plate 2, and the nozzle fixing plate 2 is located above the device housing 3;

Inside the device housing 3, from top to bottom, there are atomization area and plasma area;

The device casing 3 is a sealed plexiglass casing, and the device casing 3 is a cube with a length of 300-500mm. The front, back, left side, and right side of the plasma area of the device housing 3 are respectively provided with branch openings 9 at the central positions. The branch openings 9 are cylindrical, and the angle between the central axis and the vertical direction is 30- 60 °, the length of the branch port 9 is 50-250mm.

Each group of sliding arc electrodes 4 includes two blades and an arc blowing pipe 5, and the two blades are fixed on the electrode side fixing plate 6, leaving a distance of 1mm between the two blades; the two blades are respectively connected to the AC High-voltage power supply 8, connected to the ground wire;

The arcing air blowing pipe 5 is located between the two blades and is installed at the center of the electrode side fixing plate 6. The front end of the arcing air blowing pipe 5 is shorter than the bottom end of the blade, and the distance between the front end of the arcing air blowing pipe 5 and the bottom end of the blade is 0.5mm;

The sliding arc electrodes 4 are respectively installed at the branch 9 on the side of the plasma area of the device housing 3;

A water outlet 7 is provided at the bottom of the device housing 3, and a collecting device 10 is provided at the water outlet 7. The collection device 10 is a sealed insulating box with a volume of not less than 375L.

The branch 9 of the device housing 3 is cylindrical and inclined, and the angle between its central axis and the vertical direction is 30-60°.

The blade of the sliding arc electrode 4 is a sliding arc blade, and the tail end is provided with a threaded rod, which is installed on the electrode side fixing plate 6 through threads;

The fixed plate 6 on the electrode side is provided with multiple sets of threaded holes with different pitches for installing threaded rods.

Specifically: the blade material of the sliding arc electrode 4 is 304 white steel, the length is 100-120 mm, and the length of the threaded rod is 100-200 mm. By changing the length of the threaded rod, the distance between the atomization system and the plasma area can be changed.

There is a round hole with a diameter of 4-6mm in the center of the electrode side fixing plate 6 for fixing the arc blowing pipe 5; the electrode side fixing plate 6 is centered with 5 pairs of round holes symmetrical to the center for fixing the sliding arc electrode 4 The diameter of the round hole is the same as that of the threaded rod, and the distances between the centers of the five pairs of round holes are different. By selecting different round holes for fixing the blades, the distance between the two blades in a set of sliding arc electrodes 4 can be changed. The distance is adjustable from 1-5mm.

The method of treating wastewater with atomized plasma, the wastewater to be treated is atomized into uniform droplets through the atomization system on the upper part of the device, and sprayed to the plasma area at the lower part of the device; the atomized wastewater will all pass through the plasma area and directly contact with the plasma contact for treatment; the treated waste water automatically enters the collection device 10 to be circulated.

The flow rate of the atomized wastewater is 0-10L/min, the spraying distance is 0-1m, the spraying angle is 0-100°, and the atomized droplet size is 0-50μm.

The plasma area is generated by the sliding arc electrode 4, and the sliding arc electrode 4 is driven by a high-voltage AC power supply with an output voltage of 0-40kV and a frequency of 0-25kHz.

Air, oxygen, nitrogen or a mixture thereof with a flow rate of 1-10 L/min is fed into the arc blowing pipe 5 .

Example 1:

Waste water used in the experiment: industrial waste water.

Experimental conditions: voltage 9kV, frequency 10kHz, 5L/min of air is passed into the arc blowing pipe 5, the flow rate of the atomized wastewater is 400mL/min, the spraying distance is 0.1m, and the spraying angle is 30°. The treatment results are as follows As shown in the table:

Test items Before treatment (mg/L) After treatment ((mg/L)) COD 125000 91

Test method: potassium dichromate method (chromium method)

Example 2:

Waste water used in the experiment: industrial waste water.

Experimental conditions: voltage 10kV, frequency 12kHz, 6L/min of air is introduced into the arc blowing pipe, the flow rate of the atomized wastewater is 600mL/min, the spraying distance is 0.2m, and the spraying angle is 20°. The treatment results are shown in the table below :

Test items Before treatment (mg/L) After treatment ((mg/L)) COD 15400 twenty three

Measuring method: potassium dichromate method (chromium method)

Experimental results show that the method and device for treating wastewater with atomized plasma provided by the present invention can effectively treat industrial wastewater.

Claims (8)

1. The device for treating the wastewater by the atomized plasma is characterized by comprising an atomization system, a device shell (3) and at least one group of sliding arc electrodes (4);

the atomizing system comprises an atomizing nozzle (1) and a nozzle fixing plate (2), wherein the atomizing nozzle (1) is fixed on the nozzle fixing plate (2), and the nozzle fixing plate (2) is positioned above the device shell (3);

an atomization area and a plasma area are sequentially arranged in the device shell (3) from top to bottom;

each group of sliding arc electrodes (4) comprises two blades and an arc-starting gas blowing pipe (5), wherein the two blades are fixed on an electrode side fixing plate (6), a distance is reserved between the two blades, and the two blades are respectively connected with an alternating-current high-voltage power supply (8) and a ground wire;

the arc-starting air blowing pipe (5) is positioned between the two blades and is arranged at the circle center of the electrode side fixing plate (6), and the front end of the arc-starting air blowing pipe (5) is shorter than the bottom ends of the blades;

respectively installing sliding arc electrodes (4) at branch ports (9) on the side edge of a plasma region of a device shell (3);

a water outlet (7) is arranged at the bottom of the device shell (3), and a collecting device (10) is arranged at the water outlet (7).

2. An atomized plasma wastewater treatment plant according to claim 1, characterized in that the branch mouth (9) of the plant housing (3) is cylindrical and is arranged obliquely.

3. An atomized plasma wastewater treatment device according to claim 1, characterized in that the sliding arc electrode (4) has a sliding arc blade and a threaded rod at the end, and is mounted on the electrode side fixing plate (6) by a thread.

4. An atomized plasma wastewater treatment plant as set forth in claim 3, characterized in that the electrode-side fixing plate (6) is provided with a plurality of sets of threaded holes with different pitches for mounting threaded rods.

5. A method for treating wastewater by using atomized plasma, characterized in that the apparatus for treating wastewater by using atomized plasma according to any one of claims 1 to 4 comprises the steps of:

atomizing the wastewater to be treated into uniform liquid drops through an atomizing system on the upper part of the device, and spraying the uniform liquid drops to a plasma region on the lower part of the device;

the atomized wastewater completely passes through a plasma region and is directly contacted with plasma for treatment;

the treated wastewater automatically enters a collecting device (10) to be circularly treated.

6. A method for treating waste water with atomized plasma according to claim 5, wherein the atomized waste water has a flow rate of not more than 10L/min, a spraying distance of less than 1m, a spraying angle of not more than 100 °, and an atomized droplet diameter of less than 50 μm.

7. A method for treating wastewater according to claim 5, characterized in that said plasma region is generated by a sliding arc electrode (4), said sliding arc electrode (4) being driven by a high voltage AC power supply, the output voltage being not more than 40kV and the frequency being not more than 25kHz.

8. The method for treating wastewater by using atomized plasma as claimed in claim 5, wherein air, oxygen, nitrogen or mixed gas thereof in different proportions is introduced into the arc-starting gas blowing pipe (5) at a flow rate of 1-10L/min.

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