CN104707732A - Device and method for eliminating haze using charged particles - Google Patents

Abstract

The invention provides a device and method for eliminating fog and haze by charged particles. The meteorological data station collects meteorological data in hazy areas in real time and transmits the obtained meteorological data to the operating room; the operating room analyzes the meteorological data and calculates the occurrence of charged particles. The operating power required by the device determines the output power of the energy supply system, and transmits the operation instructions to the control system; the control system adjusts the output power of the energy supply system according to the operation instructions; the energy supply system provides energy for the charged particle generator; The particle generating device receives energy, corona discharges, and releases charged particles; charged particles enter the haze area to eliminate fog and haze. The dust removal of the present invention is non-selective, and can remove various pollutant particles in the air. Particles of all sizes have a good dust removal effect and can effectively reduce fog and haze.

Description

A device and method for eliminating fog and haze by charged particles

technical field

The invention relates to a novel method and device for eliminating fog and haze, in particular to a method for eliminating fog and haze with charged particles and a related discharge device.

Background technique

In recent years, with the rapid development of society, more and more industrial, agricultural and domestic garbage are discharged. These pollutants include not only solid pollutants, but also a large number of air pollutants, such as the exhaust gas emitted by thermal power stations in steel factories. etc. These air pollutants have caused great harm to the environment. The main components of these air pollutants are polluting gases and polluting suspended particles, especially suspended particles, which not only affect the atmospheric environment, but also bring inconvenience to people's normal life, such as the recent smog problem in major cities. At present, the impact of smog has attracted the attention of all parties, so it is more and more important to find a method to remove particulate pollutants in the air.

At present, my country's dust removal technology has matured, and dust removal equipment can be divided into five categories according to the dust removal principle: (1) Mechanical dust removal equipment; (2) Washing dust removal equipment; (3) Filter dust removal equipment; (4) Electrostatic dust removal equipment ; (5) Magnetic dust removal equipment. Among them, the dust removal efficiency of mechanical dust removal equipment is low, and it can only separate larger particles (particle size greater than 10um); the washing type dust removal equipment has a large volume, low dust removal capacity, and high water consumption, and is mostly used to treat suspended particles. Flue gas with larger diameter and higher concentration. The treatment effect on gas containing fine suspended pollutants is poor; the operation and maintenance cost of filter dust removal equipment is high, and filter bags need to be replaced frequently; the operation of magnetic dust removal is relatively stable, but its disadvantage is that it can only remove specific types of dust.

The working principle of the electrostatic precipitator is that when the gas containing pollutant particles passes through the high-voltage electric field between the cathode line connected to the high-voltage DC power supply and the grounded anode plate, the cathode corona discharge causes the gas to be ionized, and the negatively charged gas ions Under the action of the electric field force, it moves towards the anode plate. During the movement, these negatively charged gas ions collide with the pollutant particles, making these particles negatively charged, and the suspended pollutants are charged under the action of the electric field force. The anode plate moves and finally deposits on the anode plate to achieve the purpose of purifying the gas. The purification efficiency of electrostatic dust removal equipment is high, but the equipment is more complicated, the installation and maintenance costs of the equipment are high, and the dust removal effect is greatly affected by the temperature and humidity of the gas.

As mentioned above, the existing atmospheric dust removal technologies have similar deficiencies: either the dust removal efficiency is not high, almost all pollutant particles cannot be eliminated, or high installation, operation and maintenance costs are required. These factors lead to the inability of the dust removal device to achieve high efficiency. simplify. low cost. Make the general popularization of dust removal equipment to be greatly restricted. The problem of atmospheric dust removal is becoming more and more serious, and it is urgent to find a new method of dust removal to solve this problem.

Contents of the invention

In view of the above-mentioned defects in the prior art, the object of the present invention is to provide a method for effectively removing pollutant particles in the air at a relatively low cost. It can solve the problems of low efficiency, high cost and difficult popularization of existing dust removal equipment.

The principle of charge elimination of fog and haze: the natural ionization phenomenon in the atmosphere is ubiquitous. Molecules in the air are dissociated into ion pairs due to radiation dissociation, which mainly comes from galactic cosmic rays, radon isotope radiation and gamma rays from the earth's surface. These ions rarely exist independently in the atmosphere, and most of them center on this ion and gather some water molecules around it.

The nucleation process is when two or more molecules, one of which is water, mix together to form a suspended particle. There is now evidence that the ionization effect of cosmic rays can lower the nucleation barrier, thereby aggregating to form tiny suspended matter. Some of these suspended matter become condensation nuclei in the cloud. The nucleation process theoretically has the following four mechanisms:

Bimolecular nucleation: A water molecule reacts with another molecule to nucleate. Such as ammonium ions, hydrochloric acid molecules, nitric acid molecules, etc.

Trimolecular nucleation: Water molecules react with two other molecules to nucleate, which can be organic molecules or inorganic molecules.

Ion-induced nucleation: A water molecule reacts with another organic or inorganic molecule and an ion.

Ion-mediated nucleation: The reaction of a water molecule with two or more other charged organic or inorganic molecules is called ion-mediated nucleation because these nucleated molecules are charged by ions prior to the reaction.

Once an aerosol is formed, it continues to grow through several processes:

Agglomeration: Liquid water molecules attach and gather on suspended particles so that the particles grow.

Condensation: Water molecules change from a gaseous state to a liquid state and condense on suspended particles, releasing heat. Suspended particles of water molecules condense and grow, both in diameter and quality. It is worth noting that charged aerosols are more likely to attract water molecules to condense than uncharged aerosols because polar molecules condense more easily on charged bodies. Simulation results show that the growth rate of condensation of charged particles is at least two orders of magnitude higher than that of uncharged particles.

Absorption: When water droplets in the cloud come into contact with suspended particles, the suspended particles are absorbed by the water droplets. If the suspended particles are charged, these charges will be transferred to the water droplets, and these charged water droplets will more easily attract charged aerosols.

Electrostatic attraction: When a droplet of water in a cloud touches the boundary between the cloud and the air, the droplet will generally evaporate, and the charge on the droplet will be transferred to the nucleus of the droplet and to the molecules that were previously absorbed by the droplet. These charges can cause image charges in other water droplets so that the charged nuclei will be more easily absorbed by the water droplets. Even if the charge carried by the water droplet is of the same polarity as the charge carried by the nucleus, the image charge will still greatly increase the probability of being absorbed. Although there is a certain repulsion between the charge and the long distance, the natural flow of the gas will push the small particles with a diameter between 0.1um-1um close to the water droplet, so that the charge carried by the particle is the same as it is in the water droplet The mutual attraction between the image charges on the surface will cause them to gather together.

Collision: This mechanism is suitable for large water droplets in the air. When these large water droplets fall to the ground, they will collide with some other water droplets. Large water droplets fall faster than small water droplets. Therefore, during the landing process of large water droplets, they will collide with small water droplets. But even if the small water droplet is on the landing path of the large water droplet, the air pressure caused by the landing of the large water droplet will still cause the small water droplet to bypass the large water droplet without collision. It's like most small insects will not hit a big truck. The air pressure created by the big truck pushing the air will push the small insects away, so that these small insects will not hit the truck. It is worth mentioning that if the suspended particles carry 50 basic charges, the collision efficiency between suspended particles and water droplets will increase by 30 times. This may be because when the suspended particles are charged enough, it will cause a mirror image charge on the falling water droplets, making it easier to collide.

Charged molecular clusters are more likely to attract surrounding air molecules and will grow to a certain size at a faster rate than neutral, uncharged molecular clusters. These charged molecular clusters originate from the evaporation and condensation of water molecules, and once nucleated, these charged molecular clusters will be more stable. Simulation results show that if the ionization rate is increased by 25%, the concentration of particles with a particle size in the range of 3-10 nm will increase by 7-9% after 8 hours of nucleation.

Therefore, the ionization of galactic cosmic rays can cause the following three effects: 1) increase the condensation rate of aerosols, 2) reduce the nucleation barrier of aerosols, and 3) absorb other particles by water droplets in clouds. Galactic cosmic rays lower the nucleation barrier, allowing ions to attach to clusters of small water molecules, forming "micro-ions," which promote the growth of charged particles. These charged particles have a high probability of growing to a size of 100nm, which exceeds the standard of cloud condensation nuclei. Studies have also shown that charged aerosols are more likely to be absorbed by water droplets in clouds, and the particles left behind by the evaporation of these water droplets will be more likely to become ice crystal condensation nuclei.

In addition, the positive and negative charges of ions produced by galactic cosmic rays are not equal, and the number of charged particles will be greatly reduced due to the re-gathering of positive and negative ions. The positive and negative ions produced by radioactive source ionization are balanced, and most The ions produced by this ionization are lost due to recombination between ions.

On the other hand, the ions generated by corona discharge are unipolar, so these ions will repel each other and will not combine. This makes these ions will all spread into the air, or nucleate to form aerosols, or Attach to the existing suspended particles to charge the particles.

Finally, corona-discharged ions have been shown to be hygroscopic, which further facilitates the formation of charged suspended particles between ions and water droplets.

In general, naturally occurring ionization processes can cause the following effects:

a. Lower the nucleation barrier and condense to form a large number of suspended particles.

b. Make suspended particles easier to grow. The mechanism is as described above.

c. Purify the air through the aggregation of suspended particles and water droplets.

Therefore, according to the above principles, the present invention provides a device for eliminating fog and haze by charged particles, including a meteorological data station, an operating room, a control system, an energy supply system and a charged particle generating device,

The operating room is connected to the control system through a transmission line, the control system is connected to the energy supply system through a transmission line, and the energy supply system is connected to the charged particle generator through a high-voltage cable.

The meteorological data station collects local meteorological data in real time, which can be directly obtained through the local weather station, or provided by a special satellite. The meteorological data includes the temperature and humidity of the local atmosphere, the concentration of particulate matter in the air, real-time Weather conditions, etc. The meteorological data station will transmit the obtained data to the operation room, and the operation room will have a special staff to analyze the obtained meteorological data internally, and thus calculate how to operate the charged particle generator under the atmospheric conditions. The device determines whether to use the function of the device and how to use it. If the atmospheric conditions are poor and the concentration of pollutant particles is high, the operating power of the charged particle generator can be increased to make it purify the air pollution more quickly. This part of the work can be automated and remotely controlled in the later stage to save labor costs.

The operating instructions analyzed by the operating room are transmitted to the control system. The task of the control system is to operate the device and its energy supply system according to the instruction, such as turning on or off the energy supply system, adjusting the output power, etc.;

The energy supply system is the part that provides high-voltage electric energy to the charged particle generator;

The charged particle generator is the part that accepts the energy provided by the energy supply system and releases the charged particles, and it is mainly corona discharge. This part of the function can be realized in many ways, such as high voltage direct current ionization method, electron beam method and so on.

Furthermore, the energy supply system is a high-voltage power supply system, which is continuously adjustable within 3kV-50kV, and has certain self-protection functions, such as current overcurrent protection, to ensure the continuous and stable operation of the device.

Furthermore, the charged particle generating device is composed of an insulating frame and a conductive emitter electrode, the emitter electrode is wound according to the frame, and the emitter electrode is connected to the energy supply system through a high-voltage cable.

Further, the frame for installing the electrodes can be circular or square, and the frame is provided with a small hole or a mounting ring, and the emitter electrode passes through the small hole or the mounting ring on the frame and is wrapped around the frame.

Further, the emitter electrode can be a steel wire, and the steel wire passes through the small hole on the frame or the installation ring and is wound in turn to be parallel to each other, the diameter of the steel wire is between 0.3mm and 1mm, and the distance between the steel wires is between 2.5cm and 20cm, which is Because the electric fields generated by the emitting electrodes will affect each other, the efficiency of the emitted charge will decrease; if the distance is too far, the power of the emitted charge per unit area will be reduced, resulting in a reduced device effect.

Furthermore, a fan can be used to blow the charged particles generated by the charged particle generator to the haze area, which can speed up the diffusion of the charged particles. The charged particle generating device can be mounted above the fan, and the fan blows air from the bottom of the charged particle generating device to blow the charged particles upward to the smog area.

In addition, the present invention also provides a method for eliminating fog and haze by charged particles, comprising the following steps:

Step 1: The meteorological data station collects the meteorological data in the haze area in real time, and transmits the obtained meteorological data to the operation room;

Step 2: The operating room analyzes the meteorological data, calculates the operating power required by the charged particle generating device, determines the output power of the energy supply system, and transmits the operating instructions to the control system;

Step 3: The control system adjusts the output power of the energy supply system according to the operation instruction;

Step 4: The energy supply system provides energy for the charged particle generator;

Step 5: The charged particle generating device receives energy, corona discharges, and releases charged particles;

Step 6: Charged particles press in the horizontal area Formula spread, press formula in vertical area $q(x,0,z)=\frac{2Q}{{\mathrm{\&pi;}}^{1/2}{C}_{z}u{x}^{1-1/2\mathrm{no}}}\exp [\frac{-z^2}{{c_z}^2{x}^{2-\mathrm{no}}}-\frac{\mathrm{\&lambda;}}{\mathrm{\&epsiv;}}t];$ Diffusion, wherein a coordinate system is established with the position of the charged particle generating device as the origin, q(x,0,z) represents the charge density at any point (x,0,z) in the coordinate system, and q(x,y,0 ) represents the charge density of (x, y, 0) in the coordinate system, C _z represents the diffusion coefficient in the vertical direction, σ _x , σ _y are the diffusion coefficients in the horizontal direction, Q is the charge release rate, u is the average wind speed, n is Variation index (0<n<1), u is the average wind speed;

Step 6: Charged particles enter the haze area to eliminate fog and haze.

The present invention generates corona discharge through a charged particle generating device, which can reduce the nucleation barrier, condense and form a large amount of suspended particles, make the suspended particles grow more easily, and achieve the purpose of purifying air through the aggregation of suspended particles and water droplets, and the corona discharge Ions have been shown to be hygroscopic, which will further promote the formation of charged suspended particles between ions and water droplets. Compared with the traditional dust removal method, the present invention has higher efficiency, because the dust removal of charged particles is not selective, it can remove all kinds of pollutant particles in the air, and has a good dust removal effect on particles of various particle sizes, and can Effectively reduce fog and remove haze, see the examples for detailed experimental data and effects.

Description of drawings

Fig. 1 is the schematic flow chart of charged particle haze removal of the present invention;

Fig. 2 is an embodiment of the charged particle haze removal device of the present invention;

Fig. 3 is the top view of charged particle generating device in the embodiment of the present invention;

Fig. 4 is an installation embodiment between the emitter electrode and the frame of the present invention;

Fig. 5 is another installation embodiment between the emitter electrode and the frame of the present invention;

Fig. 6 is an experimental effect diagram of an embodiment of the present invention.

In the accompanying drawings, 1 is the operating room; 2 is the working power supply; 3 is the high-voltage power supply system; 4 is the high-voltage cable; 5 is the charged particle generating device; 6 is the air duct; 7 is the fan; 8 is the bracket.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary only for explaining the present invention and should not be construed as limiting the present invention.

Although the embodiments of the present invention have been shown and described, those skilled in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the invention is defined by the claims and their equivalents.

As shown in Figure 2, when the haze removal operation is required, the meteorological data station collects the meteorological data in the haze area in real time (not listed, it can be provided by the local meteorological department), and transmits the obtained meteorological data to the operating room 1 , the operating room 1 accepts the meteorological data from the meteorological data station, and can be operated by the operator after receiving the meteorological data and analyzing it, and can also be equipped with an automatic analysis operating system; the high-voltage power supply system 3 includes a control system and a high-voltage power supply. 1 Calculate the operating power required by the charged particle generator, and after determining the output power of the high-voltage power supply, make an operation instruction and transmit it to the control system. After the control system receives the instruction from the console 1, the high-voltage power supply passes the high-voltage direct current through the high-voltage cable 4 Conducted to the charged particle generator 5, the charged particle generator 5 starts corona discharge, that is, releases charged particles to carry out the haze removal process.

The charged particle generator 5 is mounted on the outlet of the air duct 6 (made of insulating material), the lower end of the air duct 6 is a fan 7, and the effect of the fan 7 is to blow upwards, and the charged particles are diffused into the atmosphere through the air duct, The fan 7 is supported by a bracket 8 , and the fan 7 is powered by the working power supply 2 .

The high-voltage power supply system 3 should ensure that the voltage is continuously adjustable within 3kV-50kV. And it has certain self-protection functions, such as current over-current protection, etc., to ensure that the device can continue to operate stably, and the energy supply system can be powered by the mains.

The insulating part in the charged particle generating device 5 is a frame, and the frame structure can be circular or other shapes. This example takes the circular frame as an example, and the optional material of the frame is epoxy board or other materials with better insulating properties; the conductive part is The emitter electrode can be made of thin steel wire, the material of which is 304 steel, and the diameter of the steel wire is between 0.3mm-1mm. After the high-voltage direct current is passed through the steel wire, due to the corona effect, the atmosphere around the steel wire is ionized to generate charged particles. As shown in Figure 3, the steel wires are wound back and forth in parallel on the circular frame. After the assembly and fixing are completed, the distance between the steel wires is between 2.5-20cm, and they are all connected to each other. The high-voltage cable 4 is directly connected to the steel wires.

As shown in Figure 4, a fixed hole is drilled on the insulating frame, and the emitter electrode is assembled and fixed by passing through the fixed hole.

As shown in Figure 5, a fixed ring is installed on the insulating frame, and the emitter electrode is assembled and fixed by passing through the fixed ring.

As shown in Figure 6, use this device to work in a polluted environment for 30 minutes, and detect PM2.5 in the atmospheric environment around the device. It can be found that before the device is turned on, the atmospheric PM2.5 value is as high as nearly 400. After the device is turned on, PM2. .5 drops rapidly, and after 30 minutes, PM2.5 has dropped to about 100, which shows that this device has a very good dust removal effect.

Diffusion state of charged particles in air:

According to the Sutton diffusion model, calculate the range of a ground device in the vertical section. Taking charge recombination losses into account: The Sutton diffusion model correction formula is: $q(x,0,z)=\frac{2Q}{{\mathrm{\&pi;}}^{1/2}{C}_{z}u{x}^{1-1/2\mathrm{no}}}\exp [\frac{-z^2}{{c_z}^2{x}^{2-\mathrm{no}}}-\frac{\mathrm{\&lambda;}}{\mathrm{\&epsiv;}}t];$ Taking the position of the charged particle generator as the origin, establish a coordinate system, where q(x,0,z) represents the charge density at any point (x,0,z) in the coordinates, Cz represents the diffusion coefficient in the vertical direction, and the constant Q is the charge release rate, u is the average wind speed, and n is the variation index (0<n<1). Take a ground device with a rated discharge power of 10Kw and a vertical updraft of 0.1m/s. According to calculations, the charge density at 1km in the vertical direction of the ground device can reach 10 ⁵ /cm ³ , so the height of the ground device’s charge release exceeds 1km.

According to the Gaussian diffusion model, calculate the range of the horizontal section of the ground device, and calculate the charge recombination loss. The correction formula of the Gaussian diffusion model is: Taking the position of the charged particle generator as the origin, establish a coordinate system, where q(x,y,0) represents the charge density of (x,y,0) in the coordinates, Q is the charge release rate, and σ _x , σ _y are Diffusion coefficient, u is the average wind speed. The rated discharge power of a ground device is 10Kw, the horizontal average airflow is 3.7m/s, and the Briggs diffusion coefficient is used in the radial direction. After calculation, the charge density of the ground device can reach 10 ⁵ /cm ³ at 20km in the downwind direction, and the radial direction is 3.6km The charge density can reach 10 ⁵ /cm ³ , and the range of action is elliptical.

Claims (9)

1. a charged particle disperses fog except the device of haze, it is characterized in that, described device comprises meteorological data station, operating room, control system, energy supply system and charged particle generating means, described operating room is connected by transmission line with control system, described control system is connected by transmission line with described energy supply system, and described energy supply system is connected by high-tension cable with described charged particle generating means.

2. according to the device described in claim 1, it is characterized in that, described device also comprises blower fan, dispels to haze region for the charged particle produced by described charged particle generating means.

3. according to the device described in claim 1, it is characterized in that, described charged particle generating means frame is above described blower fan, and charged particle, from the air supply at the bottom of described charged particle generating means, is blown into haze district by described blower fan.

4. according to the device described in claim 1, it is characterized in that, described charged particle generating means is made up of the emission electrode of the framework insulated and conduction, and described emission electrode forms according to framework coiling.

5. according to the device described in claim 4, it is characterized in that, described framework is circular or square, and described framework is provided with aperture or mounting circular ring, and described emission electrode through the aperture on described framework or installing ring coiling on said frame.

6. according to the device described in claim 5, it is characterized in that, described emission electrode is steel wire, and described steel wire turns to shape parallel to each other successively through the aperture on described framework or installing ring.

7. according to the device described in claim 6, it is characterized in that, described steel wire diameter is between 0.3mm to 1mm, and described steel wire interval is between 2.5cm to 20cm.

8. according to the device described in claim 1, it is characterized in that, described energy supply system is high voltage power supply, continuously adjustabe in 3kV-50kV.

9. use device according to any one of claim 1 to 8 to carry out the method dispersed fog except haze, it is characterized in that, comprise the following steps:

Step 1: the meteorological data in real-time collecting haze area, meteorological data station, and the meteorological data obtained is transferred to operating room;

Step 2: meteorological data analyzed by operating room, calculates the operate power needed for charged particle generating means, determines the power output of energy supply system, make operational order and be conveyed to control system;

Step 3: control system regulates according to the power output of operational order to energy supply system;

Step 4: energy supply system provides energy for charged particle generating means;

Step 5: charged particle generating means accepts energy, corona discharge, and discharges charged particle;

Step 6: charged particle is pressed at horizontal zone $q(x,y,0)=\frac{Q}{{\mathrm{\&pi;u\&sigma;}}_y{\mathrm{\&sigma;}}_z}\exp (-\frac{y^2}{{2\mathrm{\&sigma;}}_y^2}-\frac{\mathrm{\&lambda;}}{\mathrm{\&epsiv;}}t)$ Formula spreads, and presses formula in vertical area $q(x,0,z)=\frac{2Q}{{\mathrm{\&pi;}}^{1/2}{C}_z{\mathrm{ux}}^{1-1/2n}}\exp [\frac{{-z}^2}{{c_z}^2{x}^{2-n}}-\frac{\mathrm{\&lambda;}}{\mathrm{\&epsiv;}}t]$ Diffusion, wherein with described charged particle generating means position for initial point sets up coordinate system, q (x, 0, z) represent any point (x in coordinate system, 0, charge density z), q (x, y, 0) charge density of (x, y, 0) in coordinate system is represented, C _zrepresent the diffusion coefficient of vertical direction, σ _x, σ _yfor the diffusion coefficient of horizontal direction, Q is electric charge rate of release, and u is mean wind speed, and n is variability index (0<n<1), u is mean wind speed;

Step 7: charged particle enters haze district, carries out fog dispersal except haze.