CN104801135B - A kind of filter net type Wet type electric dust-removing device and method - Google Patents

Abstract

The invention discloses a filter net type wet electrostatic precipitator, which comprises a flue gas inlet device, a flue gas treatment device and a flue gas discharge device, and the flue gas inlet device, the flue gas treatment device and the flue gas discharge device are closely connected in sequence to form an integrated A semi-closed device with openings at both ends; the flue gas treatment device is equipped with a number of parallel anode plates and cathode lines between the anode plates, and the end of the anode plate is equipped with a dust collection device to capture the end of the anode escaping dust. The invention is highly efficient and intelligent, and effectively collects the dust escaping along the surface of the dust collection anode plate; increases the dust collection area of each electric field of the dust collector, improves the dust collection efficiency; avoids secondary dust pollution, and reduces the dust temperature during the wet dust cleaning process. Increase dust humidity, reduce dust specific resistance, and improve dust removal efficiency. While removing harmful substances in the atmosphere, the effective components in the pollutants are extracted and transformed into useful fertilizers, which is low-carbon and environmentally friendly, and beneficial to the sustainable development of enterprises.

Description

A filter-type wet electrostatic precipitator and method

technical field

The invention relates to electric dust removal technology, in particular to a filter-screen wet electric dust removal device and method.

Background technique

In January 2013, central and eastern my country continued to suffer from haze weather. Among them, Beijing, Hebei and other places are particularly serious, and the visibility in some areas is less than 200m. The formation of smog is inseparable from the content of fine particulate matter such as PM _2.5 in the air. Naturally, thermal power plants, which are large polluters of air, have attracted much attention. For this reason, the State Electricity Regulatory Commission urgently deployed coal-fired power plants, especially coal-fired power plants in North China, to do their utmost to reduce pollutant emissions on the basis of meeting pollution standards.

In 2013, the state successively issued a number of documents. The latest "Emission Standards of Air Pollutants for Thermal Power Plants" (GB13223-2011) lowered the smoke and dust emission limit of thermal power plants to 30mg/m ³ , and 20mg/m ³ in key areas. The "Notice on the Implementation of Ambient Air Quality Standards (GB3095-2012)" also added fine particulate matter PM _2.5 monitoring indicators for the first time, and the annual and 24-hour average concentration limits of PM _2.5 secondary standards are 35 μg/m ³ and 75 μg/m ³ respectively . The Twelfth Five-Year Plan for the Prevention and Control of Air Pollution in Key Areas proposes that 30 mg/m ³ should be used for general control areas and 20 mg/m ³ for key control areas, and coal-fired units whose smoke and dust emission concentration cannot be stably reached the standard should be retrofitted with high-efficiency dust removal. By 2015, industrial smoke and dust emissions in key areas will be reduced by 10%; 13 key areas for air pollution prevention and control will be delineated, referred to as "three districts and ten groups", and the annual average concentration of PM _2.5 will be reduced by 10%, 10%, 10%, respectively. 7%, 5%. "

At present, the control of complex pollutants has attracted great attention in the international community. For coal-fired power plants and other industrial furnaces fine particulate matter (including PM _2.5 dust, SO ₃ mist, aerosol, etc.), heavy metals (Hg, As, Se, Pb, Cr, etc.), organic compound pollutants (polycyclic aromatic hydrocarbons, The increasing attention to the discharge of compound pollutants such as dioxin, etc., makes the wet electrostatic precipitator emerge as the times require. The principle of wet electrostatic precipitator is similar to that of dry electrostatic precipitator, which needs to go through three processes of charging, dust collection and dust cleaning. But in the wet electrostatic precipitator, the water mist makes the dust condense and is collected together after charging. The water droplets collected on the plate form a water film, which can keep the plate clean. Its performance is not affected by the properties of coal ash, there is no secondary dust, no moving parts, so the operation is stable and reliable, and the dust removal efficiency is high. In addition, the wet electrostatic precipitator has a good removal effect on SO ₃ , PM _2.5 and other fine particles, which can solve the pollution problems such as gypsum rain and blue smoke acid fog caused by wet desulfurization, and can also alleviate the impact on the downstream flue, Corrosion of the chimney, reducing the cost of anti-corrosion.

With the increasingly prominent problems of the atmospheric environment and the successive promulgation of relevant environmental protection regulations such as the "Emission Standard of Air Pollutants for Thermal Power Plants" (GB13223-2011), electric dust collectors in my country's thermal power, steel, petrochemical, cement, non-ferrous, chemical and other industries have reached Less than the emission requirements of the new emission standards, the upgrading and transformation of old dust collectors have been included in the agenda of various enterprises that urgently need to solve problems. At present, in the actual transformation process, the electrostatic precipitator is changed to a bag type dust collector, the electric dust collector is changed to an electric-bag compound dust collector, the electric dust collector is changed to a rotating plate type electrostatic precipitator, and the electric dust collector is changed to a wet electrostatic precipitator. is widely used. However, in the actual transformation process, these technologies have more or less shortcomings: although the bag filter can meet the current environmental protection standards, its service life is limited, and the cost of the entire transformation project is high; the main technical advantages of the rotating plate type electrostatic precipitator It is high-efficiency, energy-saving, and widely adaptable. The main disadvantage is that it has high requirements for equipment design, manufacturing, and installation technology, and there are rotating parts, which increases the probability of failure; the existing wet electrostatic precipitator WESP uses water spray or overflow water A layer of water film is formed on the surface of the dust collecting electrode by other methods, and the dust deposited on the electrode plate is washed away by the electrostatic precipitator. No rapping device, reliable operation, high dust removal efficiency, small pressure loss, simple operation, low energy consumption, no moving parts, no secondary dust, low maintenance costs, short production downtime, and can work in flue gas The dew point temperature is lower, the compact structure can be combined with other flue gas treatment equipment, and the design forms are diversified; however, the investment cost is also relatively large, and there are still technical problems of dust escape on the surface of the dust collecting plate, which seriously affects the Dust collection efficiency. Therefore, it is imminent to seek a new type of dust removal device that is efficient, new and suitable for practical applications!

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a filter-type wet electrostatic precipitator, which can effectively solve the technical problem of dust escaping from the surface of the dust collecting plate and effectively improve the dust collection efficiency.

Technical scheme: in order to achieve the above object, the technical scheme of the present invention is as follows:

A filter-screen wet electrostatic precipitator, comprising a flue gas inlet device, a flue gas treatment device and a flue gas discharge device, the flue gas inlet device, the flue gas treatment device and the flue gas discharge device are closely connected in sequence to form an integrated two A semi-closed device with an open end; the flue gas treatment device is equipped with a number of anode plates arranged in parallel and cathode lines arranged between the anode plates, and a dust collection device is provided at the end of the anode plates to collect Dust escapes from the end of the anode plate.

Further, in the present invention, the dust collection device includes two pole plates on both sides arranged in parallel with the anode plate, that is, an upper pole plate and a lower pole plate, and the plane where the anode plate is located is located on the two sides Between the planes where the pole plates are located; a filter screen is connected to the ends of the two side plates, the filter screen and the two side plates form a groove, and the open end faces the end of the anode plate.

Further, in the present invention, the ends of the polar plates on both sides are connected with square slots, the square slots are closed on three sides and open on one side, and the opening plane is located on the same plane as the polar plates on both sides, respectively The openings of the square slots connecting the upper and lower plates face each other, and the filter screen is inserted into and out of the square slots.

Further, in the present invention, the filter screen is made of stainless steel, the aperture of the filter screen is 5-20mm, the width of the filter screen is 250-300mm, and the thickness is 2-10mm; the two sides The pole plates are made of stainless steel, and the included angle between the pole plates on both sides and the filter screen is 90°-120°.

Further, in the present invention, the filter screen is provided with a mud scraper device along one side or both sides connected to the two side plates, and the mud scraper device includes a fixed end connected to each other and a scraper plate, the fixed end is connected to one side or two sides of the filter screen; the scraper is a flat plate arranged parallel to the filter screen, and the length of the scraper is less than the width of the filter screen; The fixed end is connected with a controller to control the fixed end to move, and the fixed end drives the scraper to move.

Further, in the present invention, there are three ways in which the fixed end drives the scraper to move:

1) The fixed end drives the scraper to move up and down along the plane of the filter screen;

2) The fixed end is fixed, and the scraper is driven to rotate in a circle on the plane of the filter screen with the fixed end as the rotating shaft, and the rotation angle is 0-180°;

3) The fixed end drives the scraper to move up and down along the plane of the filter screen, and at the same time, the scraper uses the fixed end as a rotating shaft to rotate in a circle on the plane of the filter screen, and the rotation angle is 0～180°.

Further, in the present invention, the dust collection device is provided with an ultrasonic fouling detection device and a wet cleaning device, and the ultrasonic fouling detection device includes an interconnected ultrasonic fouling detector and a signal conversion and transmission device, The ultrasonic fouling detector includes a probe, the probe is selected according to the nature of the dust, and the working temperature range of the probe is -20°C to 500°C; the wet cleaning device consists of a main pipe and the end of the main pipe The connected spray device is composed of; the ultrasonic fouling detection device and the wet cleaning device are connected through a screw drive device, and the screw drive device is a stretchable elastic power device, which is fixedly connected with the beginning of the main pipeline.

Further, in the present invention, the end of the main pipeline is connected with three spraying devices, and the angle between adjacent spraying devices is 90°-120°; the spraying device includes a helical tubular A branch water pipe, the outlet of the branch water pipe is connected with a nozzle, and the nozzle is a flat rectangular bar, or a perforated plate provided with a number of holes, and the diameter of the holes is 0.2mm-2mm.

Further, in the present invention, the flue gas treatment device adopts water spray wet dust cleaning method to remove the collected dust, and an independent sewage treatment circulation device is also installed at the bottom of the flue gas treatment device, the A membrane treatment system is provided at the inlet of the sewage treatment circulation device, and a pressure sensor and a reagent storage are arranged inside the sewage treatment circulation device, and a control switch at the outlet of the reagent storage is connected to the pressure sensor, and the The sewage treatment cycle device collects the waste water generated by the flue gas treatment device through wet dust removal into the sewage treatment cycle device. When the weight of the waste water reaches the critical point of the pressure sensor, the control switch of the outlet of the reagent storage is In the open state, the ammonium salt reagent stored inside is released, and the waste water is treated, and the main components in the waste water, namely sodium sulfate and sodium nitrate, are removed by precipitation, and the obtained filtrate enters the circulation process for wet dust removal.

A method for a filter screen type wet electrostatic precipitator, comprising the following steps:

1) Dust-laden flue gas enters the flue gas treatment device, and the anode plate and dust collection device trap dust;

2) Start the mud scraper device through the controller, control the fixed end to move, and the fixed end drives the scraper to move, and the scraper removes the contact between the filter screen surface and the scraper in the moving state dust;

3) The ultrasonic fouling detection system detects the dust fouling on the inner surface of the dust collection device in real time through the ultrasonic fouling detector, and then converts and transmits the corresponding signal to the The screw drive device at the bottom of the dust collection device controls the pop-up of the screw drive device and drives the wet dust cleaning device to rise into the dust collection device, and the spray device controls the dust collection device The dust scaling on the inner surface is cleaned by water spraying; after the ultrasonic scaling detector detects in real time that the dust scaling on the inner surface of the dust collection device has been removed, then the signal conversion and transmission device will be used to The signal is converted and transmitted to the screw drive device to control the tightening of the screw drive device;

4) After the water spray wet cleaning process is finished, the waste water produced enters the sewage treatment circulation device, and firstly removes mercury by membrane filtration through the membrane treatment system; when the weight of the waste water reaches the pressure sensor At the critical point, the control switch of the outlet of the reagent storage is turned on, and the ammonium salt reagent stored in the interior is released to treat the waste water, and the main components in the waste water, i.e. sodium sulfate and sodium nitrate, are removed by precipitation. Drying, evaporation and crystallization process to make mercury-free ammonium sulfate and ammonium nitrate fertilizer; the obtained filtrate is reused as the water source of the wet ash cleaning device, and enters the circulation process for wet dust removal; the dusty flue gas passes through the flue gas treatment device After dust removal, the obtained clean flue gas is discharged from the flue gas discharge device.

Beneficial effects: Compared with the prior art, the present invention has the advantages of: it can effectively supplement the dust escaping along the surface of the anode plate for dust collection; on the basis of not changing and affecting the structure of the electric field plate line of the original dust collector, it can increase The dust collection area of each electric field of the dust collector is about 30% to 40%, effectively improving the dust collection efficiency; the overall resistance of the dust collector before and after the transformation is basically unchanged, and at the same time it can also promote the uniform distribution of the airflow of each electric field; the unique ultrasonic scaling detection and The wet dust cleaning system can not only timely and effectively remove the dust collected on the filter screen and the plates on both sides, avoid secondary dust pollution, but also reduce the dust temperature, increase the dust humidity, and reduce the dust specific resistance during the wet dust cleaning process , Improve dust removal efficiency. In addition, the unique recycling system of the dust removal system turns waste into treasure through a series of physical and chemical processes. While removing harmful substances in the atmosphere, it extracts and transforms effective components in pollutants into useful fertilizers. It is low-carbon and environmentally friendly, and beneficial to enterprises of sustainable development.

Description of drawings

Accompanying drawing 1 is the structural representation of screen type wet electrostatic precipitator of the present invention;

Accompanying drawing 2 is the structural representation of filter screen of the present invention and polar plate on both sides;

Accompanying drawing 3 is the structure diagram of the wet type ash cleaning device of the present invention.

detailed description

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

As shown in Figure 1, it is a filter-type wet electrostatic precipitator, including a flue gas inlet device, a flue gas treatment device and a flue gas discharge device, and the flue gas inlet device, flue gas treatment device and flue gas discharge device are closely connected in sequence It is an integrated semi-closed device with openings at both ends; inside the flue gas treatment device, there are a number of parallel anode plates 2 and cathode wires 4 arranged between the anode plates 2, and the end of the anode plate 2 is equipped with a dust collection device , to capture the dust escaping from the end of the anode plate 2. The dust collection device includes two pole plates 3 on both sides arranged in parallel with the anode plate 2, that is, the upper pole plate 3-1 and the lower pole plate 3-2, and the plane where the anode plate 2 is located is located between the planes where the two side pole plates 3 are located ; A filter screen 5 is connected to the ends of the pole plates 3 on both sides, and the filter screen 5 and the pole plates 3 on both sides form a groove, and the open end faces the end of the anode plate 2 .

The filter screen 5 is made of stainless steel. The aperture of the filter screen 5 is 5-20mm. The specific aperture size depends on the nature of the dust. The width of the filter screen 5 is 250-300mm and the thickness is 2-10mm. The specific thickness is determined by the designed sprayer. The strength of the shower device depends on the strength of the shower device; the plates 3 on both sides are made of 316L stainless steel, which is charged like the anode dust collecting plate, and can also collect dust; the angle between the plates 3 on both sides and the filter screen 5 is 90°～120° °, on the one hand, it is beneficial to expand the opening of the groove, which is convenient for collecting dusty smoke; , falls and collects by itself due to the action of gravity, no need to clean the water film, saving operation steps. Stainless steel material has good air permeability, corrosion resistance, high temperature resistance and mechanical strength.

As shown in Figure 2, the ends of the pole plates 3 on both sides are connected with square slots, the square slots are closed on three sides and open on one side. The opening of the square slot connected to the lower pole plate 3-2 is arranged oppositely, and the filter screen 5 is inserted into and out of the square slot.

The filter screen 5 is provided with a mud scraper device along one side or both sides connected to the pole plates 3 on both sides. The mud scraper device includes a fixed end and a scraper connected to each other, and the fixed end is connected to the single side of the filter screen 5. Or both sides are connected; the scraper is a flat plate arranged parallel to the filter screen 5, the length of the scraper is smaller than the width of the filter screen 5, and several brushes with a diameter of 0.2 to 1 mm are fixed on the plane facing the filter screen 5. The end of the brush bar is 55-20mm away from the filter screen; the fixed end is connected to a controller to control the movement of the fixed end, the fixed end drives the scraper to move, and the fixed end drives the scraper to move. There are three ways:

1) The fixed end drives the scraper to move up and down along the plane of the filter screen 5;

2) The fixed end is fixed, and the scraper is driven to make a circular rotation on the plane of the filter screen 5 with the fixed end as the rotating shaft, and the rotation angle is 0-180°, which is in the shape of a semi-circle;

3) The fixed end drives the scraper to move up and down along the plane of the filter screen 5. At the same time, the scraper rotates in a circle on the plane of the filter screen 5 with the fixed end as the rotating shaft, and the rotation angle is 0-180°.

The dust collection device is provided with an ultrasonic fouling detection device and a wet cleaning device 6. The ultrasonic fouling detection device includes an interconnected ultrasonic fouling detector and a signal conversion and transmission device. The ultrasonic fouling detector includes a probe. Dust properties are selected under working conditions, and the working temperature range of the probe is -20°C to 500°C; the wet dust cleaning device 6 is composed of the main pipe and the spray device connected to the end of the main pipe; the ultrasonic fouling detection device and wet dust cleaning The device 6 is connected by a screw drive device, which is a flexible elastic power device and is fixedly connected with the beginning of the main pipeline. When the ultrasonic fouling detector detects fouling on the filter screen and the polar plates on both sides, the spray device will use pressurized water to wash the fouled part to prevent dust fouling and blockage. The optional elastic power device of the screw drive device, such as a helical spring or an elastic coupling, is preferably made of stainless steel, which has corrosion resistance, high temperature resistance and mechanical strength; the elastic coupling can choose a spiral groove type elastic coupling The middle part of the elastic coupling is an integral sleeve with several damping grooves evenly arranged in the axial direction. The damping grooves are straight grooves for absorbing vibration and reducing vibration. error, so that the transmission movement remains accurate; the inner wall surface of the integral sleeve is covered with a layer of wear-resistant layer materials, such as wear-resistant steel junction materials and wear-resistant casting composite materials, etc., to reduce the impact of friction on the elastic coupling, and in the wear-resistant A vacuum layer is set between the grinding layer and the inner wall of the integral sleeve to further absorb and disperse the impact of vibration.

As shown in Figure 3, the end of the main pipeline is connected with three spray devices, and the angle between the adjacent spray devices is 90°～120°, which can face the filter screen 5, the upper plate 3-1 and the lower plate at the same time. Plates 3-2 are sprayed in three directions at the same time with precise alignment to improve the spraying efficiency; the spraying device includes a short pipe connected to the main pipe for transition and storage of water, and also includes a spigot tightly connected to the other end of the short pipe. The spiral tubular branch water pipe uses the effective space to extend the effective actual length of the branch water pipe to increase the water storage capacity; preferably, a buffer with a larger volume is set between the short pipe and the main pipe to store more water. For the amount of water, the buffer is provided with two or more outlets, which are respectively connected with short pipes to improve the water spraying efficiency; the outlets of the branch pipes are connected with nozzles, which are flat rectangular strips, similar to duckbills, or with several holes The perforated plate has a hole diameter of 0.2 mm to 2 mm. The water suddenly changes from a circular water pipe to a flat outlet or a perforated plate. The effects of the two methods are to make the area of the water outlet smaller, the flow speed increases, the water pressure increases, the water spray force is large, and the flushing efficiency is high.

The flue gas treatment device of the present invention removes the collected dust by means of water spraying and wet dust cleaning, and an independent sewage treatment circulation device is installed at the bottom of the flue gas treatment device, and a membrane treatment is provided at the entrance of the sewage treatment circulation device. system, there is a reagent storage inside the sewage treatment circulation device, and a pressure sensor is provided at the bottom of the sewage treatment circulation device, and the control switch at the outlet of the reagent storage is connected to the pressure sensor. When the wet ash cleaning is running, the wastewater treatment circulation device collects the waste water generated by the flue gas treatment device through wet dust removal and enters the sewage treatment circulation device. When the weight of the wastewater reaches the critical point of the pressure sensor, the control switch of the outlet of the reagent storage is turned on. state, release the internally stored ammonium salt reagent such as ammonium bicarbonate, and carry out wastewater treatment. The main components in the wastewater, namely sodium sulfate and sodium nitrate, are precipitated and removed. The obtained filtrate enters the circulation process and is used for wet dust removal; When the ash is over, the weight of the wastewater is lower than the critical point of the pressure sensor, the control switch returns to the closed state, and the release of the ammonium salt reagent is stopped.

Example

A method for a filter screen type wet electrostatic precipitator, comprising the following steps:

1) The dust-laden flue gas mainly contains SO ₂ , SO ₃ , NO _X , mercury and other pollutants. The dust-laden flue gas enters the filter-screen wet electrostatic precipitator of the present invention through the flue gas inlet device, and first passes through the equalizing orifice plate 1. Evenly disperse the dust-laden flue gas into the flue gas treatment device for dust removal; connect the cathode line 4 to the high-voltage rectifier transformer, and form a high-voltage charged electric field area together with the anode plate 2 in the flue gas treatment device; when the dust-laden smoke The gas enters the electric field area of the dust collector, passes through the electric field formed between the cathode and anode, and the high-voltage corona discharge charges the dust particles in the dusty flue gas, and the charged dust particles are adsorbed on the anode plate 2 under the action of the electric field force Although most of the dust is close to the anode plate 2, some dust particles cannot be completely captured by the anode plate 2 due to the mutual repulsion of the charged dust particles and the insufficient charge of the dust particles, and they will flow along with the airflow. The surface of the anode plate 2 escapes from the electric field region;

This part of the escaping dust is collected and adsorbed by the filter screen 5 at the end of the anode plate 2 and the grooves formed by the two side plates 3, that is, the dust collection device; Set up a row of dust collection devices as the final dust collection barrier to prevent dust from escaping and improve the cleaning efficiency of flue gas.

2) Start the mud scraper device through the operation of the controller terminal, control the fixed end to move, the fixed end drives the scraper to move, and the brush strip on the scraper preliminarily removes the excess dust on the surface of the filter screen 5 in contact with the brush strip in the moving state. Dust, saving water; the controller can be manually controlled to start and stop, and can also be connected to the ultrasonic scaling detection system. When the ultrasonic scaling detector detects the dust scaling on the inner surface of the dust collection device in real time, the signal is converted and transmitted The device converts and feeds back the corresponding signal to the controller. If the dust scaling reaches the set value, the controller terminal operates the control to start the mud scraper device.

3) When the ultrasonic fouling detection system detects that a large amount of dust is enriched in the grooves of the filter screen 5 and the plates 3 on both sides, the ultrasonic fouling detection system detects the dust on the inner surface of the dust collection device in real time through the ultrasonic fouling detector In case of fouling, the corresponding signal is converted and transmitted to the screw drive device at the bottom of the dust collection device through the signal conversion and transmission device, which controls the ejection of the screw drive device and drives the wet cleaning device at the bottom of the dust collection device 6 Automatically and quickly move up to the dust collection device, the dust removal starts, and the spray device performs water spray wet cleaning on the dust scaling on the inner surface of the dust collection device; during the cleaning process, the wet dust cleaning device 6 is in the dust collection device The filter screen 5 and the pole plates 3 on both sides are sprayed and cleaned from top to bottom in the groove, so that the dust in the groove can be removed with the flow of the flushing liquid. After the ultrasonic fouling detector detects in real time that the dust scaling on the inner surface of the dust collection device has been removed, the corresponding signal is converted and transmitted to the screw drive device through the signal conversion and transmission device to control the tightening of the screw drive device, and the wet dust cleaning device 6 Return to the bottom of the dust collection device; the whole process hardly affects the resistance of the whole device, and makes the inner surface of the groove rich in a continuous water film, remove the water film to continue the next round of dust removal, no secondary pollution, Convenient and easy to operate;

4) After the water spray wet cleaning process is completed, the waste water generated enters the sewage treatment circulation device, and firstly removes mercury by membrane filtration through the membrane treatment system; when the weight of the waste water reaches the critical point of the pressure sensor, the outlet of the reagent storage The control switch is turned on to release the internally stored ammonium salt reagents such as ammonium bicarbonate, and carry out the treatment of the wastewater chemical purification process. The main components in the wastewater, namely sodium sulfate and sodium nitrate, are precipitated and removed, and the precipitate is processed by drying, evaporation and crystallization. , to make high-quality mercury-free ammonium sulfate and ammonium nitrate fertilizers; the obtained filtrate is reused as the water source spraying of the wet ash cleaning device 6, and enters the recycling process for wet dust removal to realize recycling and resource reuse; After the flue gas is cleaned of dust and dust by the flue gas treatment device, the clean flue gas from which most of SO ₂ , SO ₃ , NO _X , mercury and other pollutants are removed is discharged from the flue gas discharge device.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (6)

1. A filter screen type wet electrostatic precipitator, characterized in that: it comprises a flue gas inlet device, a flue gas treatment device and a flue gas discharge device, and the flue gas inlet device, the flue gas treatment device and the flue gas discharge device are closely connected successively A semi-closed device connected to form an integrated semi-closed device with both ends open; the inside of the flue gas treatment device is provided with a number of parallel anode plates (2) and cathode wires (4) arranged between the anode plates (2) , the end of the anode plate (2) is provided with a dust collection device to capture the dust escaping from the end of the anode plate (2); The dust collection device comprises two pole plates (3) on both sides arranged in parallel with the anode plate (2), that is, an upper pole plate (3-1) and a lower pole plate (3-2), and the anode plate ( 2) The plane is located between the planes where the two side plates (3) are located; a filter screen (5) is connected to the ends of the two side plates (3), and the filter screen (5) and the The pole plates (3) on both sides form grooves, and the open end faces the end of the anode plate (2); The ends of the pole plates (3) on both sides are connected with square slots, the square slots are closed on three sides and open on one side, the opening plane is located on the same plane as the pole plates (3) on both sides, and is respectively connected to the upper The openings of the square slots connected to the pole plate (3-1) and the lower pole plate (3-2) are arranged facing each other, and the filter screen (5) is inserted into and out of the square slot; The dust collecting device is provided with an ultrasonic fouling detection device and a wet cleaning device (6), and the ultrasonic fouling detection device includes an interconnected ultrasonic fouling detector and a signal conversion and transmission device, and the ultrasonic fouling The detector includes a probe, and the probe is selected according to the nature of the dust, and the working temperature range of the probe is -20°C to 500°C; the wet cleaning device (6) consists of a main pipeline and a pipe connected to the end of the main pipeline. The spraying device is composed of; the ultrasonic fouling detection device and the wet cleaning device (6) are connected through a screw drive device, and the screw drive device is a scalable elastic power device, which is fixedly connected with the beginning of the main pipeline The end of the main pipeline is connected with three spraying devices, and the angle between adjacent spraying devices is 90°～120°; the spraying device includes a spiral-shaped branch water pipe, and the branch water pipe The outlet of the nozzle is connected with a nozzle, and the nozzle is a flat rectangular strip, or a perforated plate provided with several holes, and the diameter of the holes is 0.2 mm to 2 mm. 2. The filter screen type wet electrostatic precipitator according to claim 1, characterized in that: the filter screen (5) is made of stainless steel, the aperture of the filter screen (5) is 5-20mm, and the The filter screen (5) has a width of 250-300 mm and a thickness of 2-10 mm; the two-side pole plates (3) are made of stainless steel, and the gap between the two-side pole plates (3) and the filter screen (5) is The forming angle is 90°～120°. 3. The filter-screen wet electrostatic precipitator according to claim 1, characterized in that: the filter screen (5) is provided with A mud scraper device, the mud scraper device includes a fixed end connected to each other and a scraper, the fixed end is connected to one side or both sides of the filter screen (5); the scraper is arranged in parallel On the flat plate of the filter screen (5), the length of the scraper is smaller than the width of the filter screen (5); the fixed end is connected with a controller to control the movement of the fixed end, and the fixed end drives the scraper sports. 4. The filter-screen wet electrostatic precipitator according to claim 3, characterized in that: the fixed end drives the scraper to move in three ways: 1) The fixed end drives the scraper to move up and down along the plane of the filter screen (5); 2) The fixed end is fixed, and the scraper is driven to rotate in a circle on the plane of the filter screen (5) with the fixed end as the rotating shaft, and the rotation angle is 0-180°; 3) The fixed end drives the scraper to move up and down along the plane of the filter screen (5), and at the same time, the scraper uses the fixed end as a rotating shaft to work on the plane of the filter screen (5). Circular rotation, the rotation angle is 0-180°. 5. The filter-screen wet electrostatic precipitator according to claim 3, characterized in that: the flue gas treatment device adopts water spraying wet dust cleaning method to remove the collected dust, and the flue gas treatment device The bottom is also provided with an independent sewage treatment circulation device, the inlet of the sewage treatment circulation device is provided with a membrane treatment system, the inside of the sewage treatment circulation device is provided with a pressure sensor and a reagent storage, and the outlet of the reagent storage is The control switch is connected to the pressure sensor, and the sewage treatment circulation device collects the waste water generated by the flue gas treatment device through wet dust removal and enters the sewage treatment circulation device. When the weight of the waste water reaches the critical point of the pressure sensor At this time, the control switch of the outlet of the reagent storage is in the open state, the ammonium salt reagent stored in the interior is released, the waste water is treated, the main components in the waste water are removed by precipitation, i.e. sodium sulfate and sodium nitrate, and the obtained filtrate enters the circulation process , for wet dust removal. 6. The method for the filter screen type wet electrostatic precipitator according to claim 5, characterized in that: comprising the following steps: 1) The dusty flue gas enters the flue gas treatment device, and the anode plate (2) and the dust collection device trap dust; 2) Start the mud scraper device through the controller, control the fixed end to move, the fixed end drives the scraper to move, and the scraper removes the surface of the filter screen (5) and the Dust in contact with the scraper; 3) The ultrasonic fouling detection system detects the dust fouling on the inner surface of the dust collection device in real time through the ultrasonic fouling detector, and then converts and transmits the corresponding signal to the The screw drive device at the bottom of the dust collection device controls the ejection of the screw drive device, and drives the wet dust cleaning device (6) to rise into the dust collection device, and the spray device The dust scaling on the inner surface of the dust collection device is cleaned by water spraying; after the ultrasonic scaling detector detects in real time that the dust scaling on the inner surface of the dust collection device has been removed, then the signal conversion and transmission device , converting and transmitting the corresponding signal to the screw drive device to control the tightening of the screw drive device; 4) After the water spray wet cleaning process is finished, the waste water produced enters the sewage treatment circulation device, and firstly removes mercury by membrane filtration through the membrane treatment system; when the weight of the waste water reaches the pressure sensor At the critical point, the control switch of the outlet of the reagent storage is turned on, and the ammonium salt reagent stored in the interior is released to treat the waste water, and the main components in the waste water, i.e. sodium sulfate and sodium nitrate, are removed by precipitation. Drying, evaporative and crystallization processes to make mercury-free ammonium sulfate and ammonium nitrate fertilizers; the obtained filtrate is reused as the water source of the wet ash cleaning device (6), and enters the circulation process for wet dust removal; the dust-laden flue gas passes through the flue gas After the gas treatment device removes dust and dust, the obtained clean flue gas is discharged from the flue gas discharge device.