CN103073094A - Liquid layer resistor blocking discharge device and water treatment method thereof - Google Patents

Abstract

The invention relates to a liquid layer resistance blocking discharge device and a water treatment method thereof. Including water storage tank and discharge device, the water storage tank is connected with the discharge device, the discharge device is divided into upper and lower layers, the upper layer is the activated carbon fiber high voltage electrode, the plexiglass insulating layer, the activated carbon fiber ground electrode in sequence from the liquid inlet to the liquid outlet direction, and the lower layer of the discharge device It is a deflector, and the upper and lower layers form a box structure. A water pump and a flow meter are sequentially arranged between the water storage tank and the discharge device. After the discharge device enters the liquid, a liquid layer is formed on the guide plate. The activated carbon fiber high-voltage electrode and the activated carbon fiber ground electrode are placed on the liquid layer, and the high-pressure gas phase discharge reacts with the pollutants in the liquid layer, thereby removing the pollutants or pollutants in the liquid layer. Reduce the concentration of pollutants. In the present invention, the liquid layer separates the discharge space, and the discharge of the high-voltage pole area and the ground pole area occurs independently, thereby improving the breakdown voltage of the spark discharge; the contact area between the gas phase plasma and the liquid surface is doubled, thereby improving the energy of water treatment efficiency.

Description

Liquid layer resistive barrier discharge device and method for water treatment thereof

technical field

The invention relates to a method and device for high-voltage discharge water treatment.

Background technique

Liquid surface discharge water treatment is more energy efficient than submerged discharge. Due to the isolation effect of the air layer between the discharge electrode and the liquid surface, the leakage conduction current and the Joule heating effect are significantly reduced. However, the choice of electrode spacing for liquid surface discharge is limited by a pair of contradictory issues: the chemical effect of the discharge increases with the decrease of the electrode spacing, while the breakdown voltage of the spark discharge decreases with the decrease of the electrode spacing. In water treatment, it is desirable to have a discharge reactor with both high chemical effect and high spark breakdown voltage. To achieve this purpose, both the high-voltage electrode and the ground electrode are placed on the liquid surface to form a liquid layer resistance barrier discharge reactor.

Contents of the invention

The object of the present invention is to provide a brand-new liquid surface discharge reactor to improve the breakdown voltage of spark discharge and the energy efficiency of water treatment.

A liquid layer resistance blocking discharge device, including a water storage tank and a discharge device, the water storage tank is connected to the discharge device, the discharge device is divided into upper and lower layers, and the upper layer is an activated carbon fiber high-voltage electrode and a plexiglass insulating layer in sequence from the liquid inlet to the liquid outlet , Activated carbon fiber ground electrode, the lower layer of the discharge device is a deflector, and the upper and lower layers form a box structure. A water pump and a flow meter are sequentially arranged between the water storage tank and the discharge device.

A method for water treatment of the high-voltage discharge plasma generating device. After the discharge device enters the liquid, a liquid layer is formed on the guide plate with a thickness of 1-10 mm. The activated carbon fiber high voltage electrode and the activated carbon fiber ground electrode are placed in the liquid layer. Above, the distance from the liquid surface is 3-20 mm, 10-50 kV high-voltage gas-phase discharge, the activated carbon fiber high-voltage electrode and the activated carbon fiber ground electrode form a large-area and uniform plasma in the air layer, and the active substances in the plasma include Ozone, hydroxyl radicals, single oxygen radicals, and active oxygen molecules are absorbed into the liquid layer by the liquid surface, and react with pollutants in the liquid layer, thereby removing pollutants in the liquid layer or reducing the concentration of pollutants, and the treated liquid layer Return to the water storage tank to continue the circulation process.

A method for water treatment of a high-voltage discharge plasma generating device, in which 2-10 liquid layer resistance barrier discharge devices are connected in series, and the liquid to be treated flows through each liquid layer resistance barrier discharge device in sequence, forming a Liquid layer, the thickness is 1-10 mm, the activated carbon fiber high voltage electrode and the activated carbon fiber ground electrode are placed on the liquid layer, the distance from the liquid surface is 3-20 mm, 10-50 kV high voltage gas phase discharge, the activated carbon fiber high voltage electrode and the activated carbon The fiber ground electrode forms a large-area and uniform plasma in the air layer. The active substances in the plasma include ozone, hydroxyl radicals, single oxygen radicals, and active oxygen molecules are absorbed by the liquid surface into the liquid layer and polluted with the liquid layer. The substances react to remove pollutants in the liquid layer or reduce the concentration of pollutants. The treated liquid layer is discharged directly without circulation.

Beneficial effects of the present invention: the liquid layer in the present invention separates the discharge space into a high-voltage pole area and an earth pole area, and the discharge channel cannot develop continuously in the entire discharge space. Therefore, the discharge of the high-voltage pole region and the ground pole region occurs independently, thereby increasing the breakdown voltage of the spark discharge. On the other hand, also due to the separation effect of the liquid layer on the discharge space, the contact area between the gas phase plasma and the liquid surface is multiplied, thereby improving the energy efficiency of water treatment.

Description of drawings

Fig. 1 is a schematic structural diagram of a liquid layer resistive barrier discharge device.

Fig. 2 is another structural schematic diagram of the liquid layer resistive barrier discharge device.

Fig. 3 is a schematic diagram of a water treatment method of a high-voltage discharge plasma generating device.

Fig. 4 is a schematic diagram of another water treatment method of the high-voltage discharge plasma generating device.

Figure 5 is a comparison diagram of the voltage-current relationship between the resistance barrier discharge of the liquid layer and the traditional liquid surface discharge.

Fig. 6 is a comparison chart of the tetravalent sulfur oxidation rate between the liquid layer resistance barrier discharge and the traditional liquid surface discharge.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, a liquid layer resistance barrier discharge device includes a water storage tank 5 and a discharge device. The water storage tank 5 is connected to the discharge device. The discharge device is divided into upper and lower layers. Fiber high-voltage electrode 1, plexiglass insulating layer 2, activated carbon fiber ground electrode 3, the lower layer of the discharge device is a deflector 4, and the upper and lower layers form a box structure. As shown in FIG. 2 , a water pump 6 and a flow meter 7 are sequentially arranged between the water storage tank 5 of the liquid layer resistance barrier discharge device and the discharge device.

As shown in Figure 3, a kind of method of described high-voltage discharge plasma water treatment, discharge device forms liquid layer on deflector 4 after entering liquid, and thickness is 1-10 millimeter, and activated carbon fiber high voltage pole 1 and activated carbon fiber The ground electrode 3 is placed on the liquid layer, the distance from the liquid surface is 3-20 mm, and the high-voltage gas phase discharge is 10-50 kV. The activated carbon fiber high-voltage electrode 1 and the activated carbon fiber ground electrode 3 form a large area and uniform plasma in the air layer. The active substances in the plasma include ozone, hydroxyl radicals, single oxygen radicals, active oxygen molecules are absorbed by the liquid surface into the liquid layer, and react with pollutants in the liquid layer, thereby removing pollutants in the liquid layer or reducing pollution concentration of the substance, the treated liquid layer is returned to the water storage tank 5 to continue circulating treatment or directly discharged.

As shown in Fig. 4, a kind of method of described high-voltage discharge plasma water treatment is characterized in that, 2-10 discharge devices are connected in series, and the liquid to be treated flows through each liquid layer resistance blocking discharge device in sequence, A liquid layer is formed on the flow plate 4 with a thickness of 1-10 mm. The activated carbon fiber high-voltage electrode 1 and the activated carbon fiber ground electrode 3 are placed on the liquid layer with a distance of 3-20 mm from the liquid surface. 10-50 kV high-voltage gas phase discharge , the activated carbon fiber high-voltage electrode 1 and the activated carbon fiber ground electrode 3 form a large-area and uniform plasma in the air layer, and the active substances in the plasma include ozone, hydroxyl radicals, single oxygen radicals, and active oxygen molecules are absorbed by the liquid surface It enters the liquid layer and reacts with the pollutants in the liquid layer, thereby removing the pollutants in the liquid layer or reducing the concentration of pollutants. The treated liquid layer is directly discharged without circulation.

Example

Using the liquid layer resistance barrier discharge technology of the present invention to oxidize tetravalent sulfur in aqueous solution, the conductivity of the solution is 20 mS.cm ^-1 , the initial pH of the solution is 3, the initial concentration of tetravalent sulfur is 2 mmol/L, and the activated carbon fiber high voltage electrode The length and width of the activated carbon electrode are both 17.5cm, the thickness of the liquid layer on the guide plate is 7mm, and the volume of the treated solution is 2 L. The single pulse energy used is 25 mJ, the voltage is 37 kV, and the pulse frequency is 100 pulses per second.

Figure 5 shows the comparison of the voltage-current relationship between the liquid layer resistive barrier discharge and the traditional liquid surface discharge. It can be seen that the current of the liquid layer resistance blocking discharge is significantly lower than that of the traditional liquid surface discharge, which proves that the liquid layer resistance discharge can limit the current from rising too fast, thereby increasing the breakdown voltage of the spark discharge.

Figure 6 shows the comparison of the tetravalent sulfur oxidation rate between the liquid layer resistance barrier discharge and the traditional liquid surface discharge. It can be seen that under the same single pulse energy, the oxidation rate of tetravalent sulfur oxidized by liquid layer resistance barrier discharge is significantly higher than that of traditional liquid surface discharge, which proves that liquid layer resistance barrier discharge can improve the rate and energy of high voltage discharge plasma water treatment efficiency.

When the amount of water to be treated is small, the discharge device of the present invention can be used independently to circulate the water to be treated. When the treatment flux is large, the discharge device of the present invention can be used as a discharge unit of a large flux continuous flow treatment system.

Claims (4)

1. liquid layer resistance discharge-blocking device, it is characterized in that, it comprises two-layer up and down, the upper strata is followed successively by activated carbon fiber high-pressure stage (1), synthetic glass insulation layer (2), activated carbon fiber ground electrode (3) from feed liquor to the fluid direction, electric discharge device lower floor is flow deflector (4), up and down two-layer composition body structure.

2. high-voltage discharge plasma water treatment device according to claim 1 is characterized in that, is provided with successively water pump (6) and under meter (7) between aqua storage tank (5) and the electric discharge device.

3. the method for a high-voltage discharge plasma water treatment according to claim 1 and 2, it is characterized in that, form liquid layer at flow deflector (4) behind the electric discharge device feed liquor, thickness is the 1-10 millimeter, activated carbon fiber high-pressure stage (1) places on the liquid layer with activated carbon fiber ground electrode (3), with the liquid level spacing be the 3-20 millimeter, the discharge of 10-50 kilovolt high pressure vapor, activated carbon fiber high-pressure stage (1) forms big area and uniform plasma body with activated carbon fiber ground electrode (3) in gas cloud, active substance in the plasma body comprises ozone, hydroxyl radical free radical, single oxyradical, active oxygen species is absorbed by liquid level and enters liquid layer, react with pollutent in the liquid layer, thereby the concentration of pollutent or reduction pollutent in the removal liquid layer, treated liquid layer is back to aqua storage tank (4) and continues circular treatment.

4. the method for a high-voltage discharge plasma water treatment according to claim 1 and 2, it is characterized in that, with 2-10 electric discharge device series connection, pending liquid flows through each liquid layer resistance discharge-blocking device successively, form liquid layer at flow deflector (4), thickness is the 1-10 millimeter, activated carbon fiber high-pressure stage (1) places on the liquid layer with activated carbon fiber ground electrode (3), with the liquid level spacing be the 3-20 millimeter, 10-50 kilovolt high pressure vapor parallel discharge, activated carbon fiber high-pressure stage (1) forms big area and uniform plasma body with activated carbon fiber ground electrode (3) in gas cloud, active substance in the plasma body comprises ozone, hydroxyl radical free radical, single oxyradical, active oxygen species is absorbed by liquid level and enters liquid layer, react with pollutent in the liquid layer, thereby remove pollutent in the liquid layer or reduce the concentration of pollutent; Liquid layer after treatment directly discharges.

Images