Online arsenic and selenium removal system and method for waste incineration power plant

Abstract

The invention relates to the technical field of environmental protection, in particular to an arsenic and selenium online removal system and method for a waste incineration power plant. In the working process, the system obtains fly ash on line from a dust remover of a waste incineration power plant, the fly ash is modified through the on-site chemical and ball-milling integrated modification device to prepare an efficient arsenic-selenium adsorbent, and then the efficient arsenic-selenium adsorbent is conveyed and sprayed into a flue to adsorb pollutants such as arsenic and selenium in flue gas. The adsorbent raw materials are obtained on site in the waste incineration power plant, online modification and further injection adsorption can reduce emission of pollutants such as arsenic and selenium to the atmosphere, the situation that the adsorbent raw materials are obtained from the outside of the waste incineration power plant is avoided, the pollutant control cost is reduced, and the automatic operation level is improved. Namely, the system can realize integrated operation of on-site feeding, modification, injection and adsorption, and can meet the requirement of adsorbing and removing discharged pollutants such as arsenic and selenium in flue gas of coal-fired power plants of units with different capacities.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection, and particularly relates to an online arsenic and selenium removal system and method for a waste incineration power plant. Background Art

[0002] As (i.e., arsenic) and Se (i.e., selenium) have strong volatility. During waste incineration, they will volatilize and vaporize and accumulate in fly ash. If the fly ash is not treated and allowed to be discharged with the flue gas, it will surely cause certain harm to the environment. Arsenic is a heavy metal that widely exists in nature. Exposure to arsenic is very harmful to human health. When waste is incinerated, arsenic will volatilize into a gaseous state and accumulate in fly ash, and will be discharged into the atmosphere with the tail flue gas, which will cause great harm to the environment and human production and life. Selenium is a non-metallic element that is widely used in production and life. It is usually used as a catalyst in the electrolytic manganese industry, photosensitive materials, etc. During waste incineration, selenium in sludge is basically released as SeO2 and accumulates in fly ash and is released into the environment, which not only harms the atmospheric environment, but also generates corresponding selenite and selenate when SeO2 dissolves in water. Due to the enrichment effect of soil and plants, the selenium content in soil and plants will be excessive. Therefore, there is an urgent need to provide an online arsenic and selenium removal system and method for a waste incineration power plant to reduce the emissions of arsenic and selenium pollutants from the waste incineration power plant. Summary of the Invention

[0003] The present invention provides an online arsenic and selenium removal system and method for a waste incineration power plant, which can reduce the emissions of arsenic and selenium pollutants from the waste incineration power plant.

[0004] In a first aspect, an embodiment of the present invention provides an online arsenic and selenium removal system for a waste incineration power plant, including a waste incinerator, an acid scrubber, a dust collector, and a chimney arranged in sequence along the flue gas flow direction, and further including an online arsenic and selenium removal device connected between the dust collector and the tail flue of the waste incinerator. The online arsenic and selenium removal device includes a raw material ash bin, a grinding bin, a cyclone separator, a modified ash bin, a spray tank, and a mixer arranged in sequence along the fly ash conveying direction. The online arsenic and selenium removal device further includes a gas-liquid atomizing nozzle respectively connected to the outlet of the raw material ash bin and the inlet of the grinding bin. The gas outlet of the cyclone separator is connected to the mixer. The mixer is further connected to a compressed air source. The outlet of the mixer is connected to the inlet of an ejector. The outlet of the ejector is located in the tail flue of the waste incinerator. The gas-liquid atomizing nozzle is used to spray a modified liquid, and the modified liquid is used to adsorb arsenic and selenium in the flue gas onto the fly ash.

[0005] In a second aspect, an embodiment of the present invention provides an online arsenic and selenium removal method for a waste incineration power plant, based on the system mentioned in the above embodiment, including:

[0006] Inject the modified liquid using the gas-liquid atomizing nozzle to achieve gas-solid mixing of the modified liquid and the fly ash in the raw material ash bin.

[0007] Grind the product of gas-solid mixing using the grinding bin.

[0008] Carry the ground product through the cyclone separator by the primary air so that the solid-phase product enters the modified ash bin for storage.

[0009] Under the action of the gas discharged from the cyclone separator and the compressed air source, mix with the modified ash in the modified ash bin in the mixer, and inject the modified ash into the tail flue of the waste incinerator through the injector to remove arsenic and selenium pollutants in the flue gas.

[0010] After adopting the above technical solution, the beneficial effects are as follows:

[0011] During the working process, the system obtains fly ash online from the dust collector of the waste incineration power plant, modifies it into an efficient arsenic and selenium adsorbent through an on-site chemical and ball milling integrated modification device, and then transports and injects it into the flue to adsorb arsenic, selenium and other pollutants in the flue gas. The present invention can reduce the emission of arsenic, selenium and other pollutants into the atmosphere by obtaining adsorbent raw materials on-site in the waste incineration power plant, online modification and further injection adsorption, avoiding obtaining adsorbent raw materials from outside the waste incineration power plant, reducing the pollutant control cost and improving the automatic operation level. That is, the system can realize the integrated operation of on-site feeding, modification, injection and adsorption, and can meet the adsorption and removal of arsenic, selenium and other pollutants in the flue gas of coal-fired power plants with different capacities. Description of the Drawings

[0012] Figure 1 It is a schematic diagram of the principle of the arsenic and selenium online removal system of the waste incineration power plant provided by the embodiment of the present invention;

[0013] Figure 2 is Figure 1 a schematic diagram of the structure of the arsenic and selenium online removal device in the arsenic and selenium online removal system shown;

[0014] Figure 3 is Figure 2 a schematic diagram of the structure of the gas-liquid atomizing nozzle in the arsenic and selenium online removal device shown.

[0015] Reference Numerals:

[0016] 1 - Waste incinerator; 2 - Deacidification tower; 3 - Dust collector; 4 - Chimney; 11 - Raw material ash bin; 12 - Grinding bin; 13 - Cyclone separator; 14 - Modified ash bin; 15 - Blowing tank; 16 - Mixer; 17 - Gas-liquid atomizing nozzle; 18 - Compressed air source; 19 - Injector; 21 - First grinding chamber; 22 - Second grinding chamber; 23 - First grinding balls; 24 - Second grinding balls; 25 - Partition; 31 - Gas-liquid inlet area; 32 - Eddy current formation area; 33 - Homogenization area; 34 - Outlet regulation area; 35 - Injection regulator; 41 - Gas inlet; 42 - Liquid inlet; 43 - Rotating blades; 44 - Spiral flow channel; 45 - Cleaning liquid distributor; 46 - Heater; 47 - Drain valve; 51 - Feed valve, 52 - Discharge valve; 53 - Level gauge; 61 - First CEMS detection component; 62 - Second CEMS detection component.

[0017] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments in line with the present invention, and are used together with the specification to explain the principles of the present invention. Detailed implementation manners

[0018] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in combination with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] In the description of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; unless otherwise specified or stated, the term "plural" means two or more; the terms "connection", "fixation", etc. should all be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In the description of this specification, it should be understood that the orientation terms such as "upper" and "lower" described in the embodiments of the present invention are described from the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected "above" or "below" another element, it can not only be directly connected "above" or "below" another element, but also be indirectly connected "above" or "below" another element through an intermediate element.

[0021] Such as Figure 1 and Figure 2As shown in the figure, an on-line arsenic and selenium removal system for a waste incineration power plant is provided in an embodiment of the present invention. The system includes a waste incinerator 1, a deacidification tower 2, a dust collector 3, and a chimney 4 arranged in sequence along the flue gas flow direction. It also includes an on-line arsenic and selenium removal device connected between the dust collector 3 and the tail flue of the waste incinerator 1. The on-line arsenic and selenium removal device includes a raw material ash bin 11, a grinding bin 12, a cyclone separator 13, a modified ash bin 14, a spray tank 15, and a mixer 16 arranged in sequence along the fly ash conveying direction. The on-line arsenic and selenium removal device also includes a gas-liquid atomizing nozzle 17 respectively connected to the outlet of the raw material ash bin 11 and the inlet of the grinding bin 12. The gas outlet of the cyclone separator 13 is connected to the mixer 16. The mixer 16 is also connected to a compressed air source 18. The outlet of the mixer 16 is connected to the inlet of an ejector 19. The outlet of the ejector 19 is located in the tail flue of the waste incinerator 1. The gas-liquid atomizing nozzle 17 is used to spray a modified liquid, and the modified liquid is used to adsorb arsenic and selenium in the flue gas onto the fly ash.

[0022] In this embodiment, during the working process, the system obtains fly ash online from the dust collector of the waste incineration power plant, prepares a high-efficiency arsenic and selenium adsorbent through on-site chemical and ball milling integrated modification, and then transports and sprays it into the flue to adsorb pollutants such as arsenic and selenium in the flue gas. The present invention can reduce the emission of pollutants such as arsenic and selenium into the atmosphere by obtaining adsorbent raw materials on-site in the waste incineration power plant, on-line modification, and further spraying and adsorption, avoiding obtaining adsorbent raw materials from outside the waste incineration power plant, reducing the pollutant control cost, and improving the automation operation level. That is, the system can realize the integrated operation of on-site feeding, modification, spraying, and adsorption, and can meet the adsorption and removal of pollutants such as arsenic and selenium in the flue gas of coal-fired power plants with different capacities.

[0023] In some embodiments, the cyclone separator 13 is used to separate the modified ash particles from the dust-containing gas flow from the mill. After separation, the gas is sent into the mixer 16 to assist in feeding, and the modified ash particles are sent into the modified ash bin 14 for storage.

[0024] In some embodiments, the spray tank 15 adopts a series tank or parallel tank arrangement method, which can realize continuous and stable spraying of the powder adsorbent. Logic control feeding is realized under the monitoring of the level gauge to ensure the continuity of spraying. At the same time, the spray tank itself has a pressure balancing device to avoid pressure fluctuations in the tank during the feeding and dosing processes and prevent pulsed flow during the adsorbent spraying process.

[0025] In some embodiments, the ejector 19 is composed of a spray main pipe, a multi-way distributor, and a spray gun. The internal structure of the multi-way distributor is optimized and designed through theoretical calculation, numerical analysis, and verification by an isometric model experiment. The discharge amount distribution accuracy of each branch pipe can reach ±5%.

[0026] In some embodiments, the modified high-efficiency fly ash adsorbent in the system can be injected into the flue before the economizer, and the adsorbent is evenly atomized and injected through multiple injection ports of the powder injector, improving the contact opportunity and mass transfer effect between the adsorbent and pollutants such as arsenic and selenium in the flue.

[0027] In an embodiment of the present invention, a primary grinding chamber 21 and a secondary grinding chamber 22 are sequentially arranged in the grinding bin 12 along the fly ash flow direction. A primary grinding ball 23 is arranged in the primary grinding chamber 21, and a secondary grinding ball 24 is arranged in the secondary grinding chamber 22. The diameter of the primary grinding ball 23 is larger than that of the secondary grinding ball 24. The primary grinding chamber 21 and the secondary grinding chamber 22 are separated by at least two partition plates 25, and each partition plate 25 is provided with a through hole.

[0028] In this embodiment, the primary grinding ball 23 in the primary grinding chamber 21 has a larger diameter and is used for grinding coarser ash particles. The finer ash particles are blown into the secondary grinding chamber 22 by the primary air flow. The secondary grinding ball 24 in the secondary grinding chamber 22 has a smaller diameter and is used for further grinding of the ash particles, while promoting the reaction between the modifier and the inside of the ash particles. The modified ash particles ground to the required fineness enter the cyclone separator 13 along with the primary air. The gap between the two partition plates 25 is a buffer area, so that the coarser ash particles and the finer ash particles can be separated, so that the grinding effect can be better realized, and it is not easy to be blocked in the partition plate 25.

[0029] As Figure 3 shown, in an embodiment of the present invention, the gas-liquid atomizing nozzle 17 includes a gas-liquid inlet area 31, a vortex formation area 32, a homogenization area 33, and an outlet adjustment area 34 arranged in sequence. The gas-liquid inlet area 31 is provided with a gas inlet 41 and a liquid inlet 42 that are perpendicular to each other. The gas inlet 41 is used to introduce the carrier gas, and the liquid inlet 42 is used to introduce the modifying liquid. The vortex formation area 32 is used to form a high-speed vortex gas-liquid fluid. The homogenization area 33 is used to make the gas-liquid fluid stable and uniform. The outlet adjustment area 34 is used to adjust the flow rate of the gas-liquid fluid. An injection regulator 35 is arranged outside the gas-liquid atomizing nozzle 17, and the injection regulator 35 is used to adjust the injection angle of the outlet adjustment area 34.

[0030] In this embodiment, the gas-liquid injection atomizing nozzle can introduce the carrier gas and the liquid into the cavity according to the type of the required modifying liquid, the amount of the modifying liquid, and the requirement of the carrier gas. The carrier gas flow carrying the large-particle modifying liquid enters the spiral flow channel through the rotating blades. For the carrier gas and the modifying liquid entering the spiral flow channel, the carrier gas and the liquid generate a high-speed vortex in the cavity, and the liquid is sheared into tiny liquid droplets and fully mixed in the carrier gas flow. After the vortex is formed, the mixed gas flow enters the homogenization area and passes through the flow channel with gradually decreasing aperture, making the gas-liquid flow more stable and the liquid droplet diameter uniform. Finally, the mixed gas-liquid fluid enters the atomizing nozzle part through an adjustable outlet.

[0031] In an embodiment of the present invention, a rotating blade 43 is provided at the inlet of the eddy current forming region 32. The rotating blade 43 is used to shear the modified liquid into liquid beads during rotation. A spiral flow channel 44 is provided inside the eddy current forming region 32 to form a gas-liquid fluid with a high-speed eddy current.

[0032] In an embodiment of the present invention, the rotating blade 43 is inclined and has an arc-shaped or spiral shape to facilitate the generation of a high-speed eddy current; a spoiler (not shown in the figure) is provided in the eddy current forming region 32 to further increase the mixing degree of the gas-liquid fluid before entering the homogenization region 33.

[0033] In this embodiment, the gas-liquid jet atomizing nozzle can mix the carrier gas with the liquid beads to form a uniform liquid bead gas flow, which is efficiently sprayed into the mill. Among them, the gas-liquid mixing chamber is the core component of the device. The design of the tapered spiral flow channel can ensure that the carrier gas and the liquid can be quickly and uniformly mixed after entering the chamber for subsequent atomizing spraying. At the same time, measures such as the tangential injection of the liquid injector, the rotating blade, the spoiler, the rotating component, and the tapered channel in the homogenization region are adopted to achieve the best gas-liquid mixing effect.

[0034] In an embodiment of the present invention, a cleaning liquid distributor 45 is provided at the inlet of the spiral flow channel 44. The cleaning liquid distributor 45 is used to connect to the outer surface of the housing of the eddy current forming region 32 with a heater 46. An auxiliary flow channel is provided on the spiral flow channel 44. A drain valve 47 is provided at the end of the eddy current forming region 32. The cleaning liquid distributor 45 is used to spray the cleaning liquid. The cleaning liquid is used to clean the impurities on the inner surface of the housing of the eddy current forming region 32. The cleaning liquid can flow along the spiral flow channel 44 and the auxiliary flow channel. The heater 46 is used to heat the housing of the eddy current forming region 32. The drain valve 47 is used to discharge the cleaning liquid after cleaning the impurities.

[0035] In this embodiment, the self-cleaning system of the gas-liquid jet atomizing nozzle is provided with a cleaning liquid supply device, an auxiliary flow channel, a cleaning liquid distributor containing a pressure pump, a drain valve, a drain pipe, and an automatic control system. The self-cleaning system of the gas-liquid jet atomizing nozzle is commanded by the automatic control system and starts to work when the volume of the modified ash in the modified ash storage bin level gauge exceeds. The independent container for storing the cleaning liquid can select a suitable cleaning liquid according to the usage situation, such as water, cleaning agent, or solvent with special components. A distributor is provided at the inlet of the auxiliary flow channel to evenly distribute the cleaning liquid to each flow channel and improve the cleaning efficiency. The auxiliary flow channel is connected to the spiral flow channel and assists in guiding the cleaning liquid to the surfaces of the blades and guide vanes during the cleaning process to wash away the attached impurities. After the cleaning is completed, the flowing cleaning liquid is discharged through the drain pipe and enters the recycling device or the waste liquid treatment device to ensure the environmental protection and economy of the cleaning.

[0036] In an embodiment of the present invention, a feed valve 51 is provided at the inlet of the raw material ash bin 11, and a discharge valve 52 is provided at the outlet. A level gauge 53 is provided in the modified ash bin 14. When the level gauge 53 detects that the height of the modified ash in the modified ash bin 14 exceeds the preset height, the feed valve 51, the discharge valve 52, the injection regulator 35, the gas-liquid atomizing nozzle 17 and the cyclone separator 13 are closed, and the cleaning liquid distributor 45, the heater 46 and the blowdown valve 47 are opened; when the level gauge 53 detects that the height of the modified ash in the modified ash bin 14 does not exceed the preset height, the feed valve 51, the discharge valve 52, the injection regulator 35, the gas-liquid atomizing nozzle 17 and the cyclone separator 13 are opened, and the cleaning liquid distributor 45, the heater 46 and the blowdown valve 47 are closed.

[0037] In this embodiment, the self-cleaning system of the gas-liquid injection atomizing nozzle is controlled by the level gauge of the modified ash bin. When the volume of the modified ash in the level gauge of the modified ash bin exceeds 3 / 4, the mill switch is turned on, the mill stops running, the feed valve 51, the discharge valve 52, the injection regulator 35, the gas-liquid atomizing nozzle 17 and the cyclone separator 13 are closed, and the primary air stops entering. The liquid injector of the gas-liquid device atomizing nozzle is closed, the carrier gas stops entering, the cleaning liquid distributor containing a pressure pump is opened, the blowdown valve is opened, the cleaning liquid starts to clean along the spiral flow path and the auxiliary flow path, and the cleaning waste liquid is discharged from the blowdown port. After the cleaning is completed, the electric heater is turned on to evaporate the moisture inside the nozzle; when the volume of the modified ash in the level gauge of the modified ash bin is lower than 1 / 4, the self-cleaning system of the gas-liquid injection atomizing nozzle is closed, and the ball milling modification system is restarted. The whole process is monitored by an automatic control system to ensure that it automatically resumes the normal working state after cleaning is completed.

[0038] In an embodiment of the present invention, a first CEMS detection component 61 is provided in the flue upstream of the injector 19, and a second CEMS detection component 62 is provided in the flue downstream of the dust collector 3. The injection amounts of the modification liquid and the modified ash are determined based on the arsenic and selenium pollutant concentrations detected by the first CEMS detection component 61 and the second CEMS detection component 62.

[0039] In an embodiment of the present invention, the injection amounts of the modification liquid and the modified ash are determined by the following formula:

[0040] y1 = a1(C1 - C2) 3 + a2(C1 - C2) 2 + a3(C1 - C2)+ a4

[0041] y2 = (b2(y1 3 + y1 2 + y1 + b1)) / 1000

[0042] Wherein, y1 is the injection amount of the modification liquid, in g / h; y2 is the injection amount of the modified ash, in kg / h; a1, a2, a3, a4, b1, and b2 are all dimensionless preset coefficients; C1 is the concentration of arsenic and selenium pollutants detected by the first CEMS detection component 61, in ppm; C2 is the concentration of arsenic and selenium pollutants detected by the second CEMS detection component 62, in ppm.

[0043] During the working process, the controller is connected to each sensor to read parameters, combines the operation load and raw material quantity of the waste incineration power plant, and transmits them to the industrial control computer. According to the control requirements of arsenic and selenium pollutants and the actual operation conditions, the optimal injection amounts of the modification liquid, air volume, and fly ash adsorbent injection for arsenic and selenium removal process are obtained, and then fed back to the controller, thereby performing real-time adjustment on each actuator. Through the operation of the control system, automatic loading and unloading of the raw material ash bin, continuous feeding of the injection tank in the pneumatic injection system, real-time adjustable injection amount of the adsorbent, and timed self-cleaning of the self-cleaning system of the gas-liquid injection atomizing nozzle can be achieved.

[0044] In addition, the embodiment of the present invention also provides an on-line arsenic and selenium removal method for a waste incineration power plant, based on the system mentioned in any one of the above embodiments, including:

[0045] Using the gas-liquid atomizing nozzle 17 to inject the modification liquid to enable gas-solid mixing of the modification liquid and the fly ash in the raw material ash bin 11;

[0046] Using the grinding bin 12 to grind the product of the gas-solid mixing;

[0047] Carrying the ground product through the cyclone separator 13 by the primary air to enable the solid-phase product to enter the modified ash bin 14 for storage;

[0048] Under the action of the gas discharged from the cyclone separator 13 and the compressed air source 18, mixing with the modified ash in the modified ash bin 14 in the mixer 16, and injecting the modified ash into the tail flue of the waste incinerator 1 through the injector 19 to remove arsenic and selenium pollutants in the flue gas.

[0049] It can be understood that the method embodiment and the system embodiment provided by the present invention are based on the same inventive concept, and both have the same beneficial effects. Therefore, the beneficial effects of the method embodiment will not be elaborated herein.

[0050] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An online arsenic and selenium removal system for a waste incineration power plant, characterized in that: The invention comprises a waste incinerator (1), a deacidification tower (2), a dust collector (3) and a chimney (4) which are sequentially arranged along the flue gas flow direction, and also comprises an arsenic-selenium online removal device connected between the dust collector (3) and the tail flue of the waste incinerator (1), wherein the arsenic-selenium online removal device comprises a raw ash bin (11), a grinding bin (12), a cyclone separator (13), a modified ash bin (14), a blowing tank (15) and a mixer (16) which are sequentially arranged along the fly ash conveying direction, and the arsenic-selenium online removal device also comprises a raw ash bin (11), a grinding bin (12), a cyclone separator (13), a modified ash bin (14), a blowing tank (15) and a mixer (16) which are respectively connected to the raw ash bin ( The gas-liquid atomizing nozzle (17) is connected to the outlet of the cyclone separator (11) and the inlet of the grinding chamber (12), the gas outlet of the cyclone separator (13) is connected to the mixer (16), the mixer (16) is also connected to a compressed air source (18), the outlet of the mixer (16) is connected to the inlet of an injector (19), the outlet of the injector (19) is located in the tail flue of the waste incinerator (1), the gas-liquid atomizing nozzle (17) is used to inject a modifying liquid, and the modifying liquid is used to adsorb arsenic and selenium in the flue gas onto fly ash.

2. The system according to claim 1, characterized in that A primary grinding chamber (21) and a secondary grinding chamber (22) are sequentially arranged in the grinding bin (12) along the flow direction of fly ash; a primary grinding ball (23) is arranged in the primary grinding chamber (21); a secondary grinding ball (24) is arranged in the secondary grinding chamber (22); the diameter of the primary grinding ball (23) is greater than the diameter of the secondary grinding ball (24); the primary grinding chamber (21) and the secondary grinding chamber (22) are separated by at least two partitions (25); each of the partitions (25) is provided with a through hole.

3. The system according to claim 1, characterized in that The gas-liquid atomizing nozzle (17) comprises a gas-liquid inlet area (31), a vortex forming area (32), a homogenizing area (33) and an outlet regulating area (34) which are arranged in sequence. The gas-liquid inlet area (31) is provided with a gas inlet (41) and a liquid inlet (42) which are perpendicular to each other. The gas inlet (41) is used to introduce a carrier gas, and the liquid inlet (42) is used to introduce a modified liquid. The vortex forming area (32) is used to form a gas-liquid fluid with a high-speed vortex. The homogenizing area (33) is used to make the gas-liquid fluid stable and uniform. The outlet regulating area (34) is used to adjust the flow rate of the gas-liquid fluid. An injection regulator (35) is arranged outside the gas-liquid atomizing nozzle (17), and the injection regulator (35) is used to adjust the injection angle of the outlet regulating area (34).

4. The system according to claim 3, characterized in that A rotating blade (43) is provided at the entrance of the vortex forming zone (32), and the rotating blade (43) is used to shear the modified liquid into liquid droplets during the rotation process. A spiral flow channel (44) is provided inside the vortex forming zone (32) to form a high-speed vortex gas-liquid fluid.

5. The system according to claim 4, characterized in that The rotating blades (43) are inclined and have an arc or spiral shape to facilitate the generation of high-speed vortices; spoilers are provided in the vortex forming area (32) to further increase the degree of mixing of the gas and liquid fluids before entering the homogenizing area (33).

6. The system according to claim 4, characterized in that A cleaning liquid distributor (45) is provided at the entrance of the spiral flow channel (44), and the cleaning liquid distributor (45) is connected to a heater (46) on the outer surface of the shell of the vortex forming area (32). An auxiliary flow channel is provided on the spiral flow channel (44), and a drain valve (47) is provided at the end of the vortex forming area (32). The cleaning liquid distributor (45) is used to spray cleaning liquid, and the cleaning liquid is used to clean impurities on the inner surface of the shell of the vortex forming area (32). The cleaning liquid can flow along the spiral flow channel (44) and the auxiliary flow channel. The heater (46) is used to heat the shell of the vortex forming area (32), and the drain valve (47) is used to discharge the cleaning liquid after cleaning the impurities.

7. The system according to claim 6, characterized in that The inlet of the raw ash bin (11) is provided with a feed valve (51), the outlet is provided with a discharge valve (52), and the modified ash bin (14) is provided with a level meter (53). When the level meter (53) detects that the height of the modified ash in the modified ash bin (14) exceeds a preset height, the feed valve (51), the discharge valve (52), the injection regulator (35), the gas-liquid atomizing nozzle (17) and the cyclone separator (13) are closed, and the cleaning liquid The distributor (45), the heater (46) and the drain valve (47) are opened; when the material level meter (53) detects that the height of the modified ash in the modified ash bin (14) does not exceed the preset height, the feed valve (51), the discharge valve (52), the injection regulator (35), the gas-liquid atomizing nozzle (17) and the cyclone separator (13) are opened, and the cleaning liquid distributor (45), the heater (46) and the drain valve (47) are closed.

8. The system according to any one of claims 1 to 7, characterized in that: A first CEMS detection component (61) is provided in the flue upstream of the injector (19), and a second CEMS detection component (62) is provided in the flue downstream of the dust collector (3). The injection amount of the modified liquid and the injection amount of the modified ash are determined based on the concentrations of arsenic and selenium pollutants detected by the first CEMS detection component (61) and the second CEMS detection component (62).

9. The system according to claim 8, characterized in that The injection amount of the modified liquid and the injection amount of the modified ash are determined by the following formula: <h2 style=";text-align:left;direction:ltr">y1 = a1(C1-C2)<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +a2(C1-C2)<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +a3(C1-C2)+a4 <h2 style=";text-align:left;direction:ltr">y2 = (b2) (y1)<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +y1<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +y1+b1)) / 1000 In the formula, y1 is the injection amount of the modified liquid, g / h; y2 is the injection amount of the modified ash, kg / h; a1, a2, a3, a4, b1 and b2 are all dimensionless preset coefficients; C1 is the concentration of arsenic and selenium pollutants detected by the first CEMS detection component (61), ppm; C2 is the concentration of arsenic and selenium pollutants detected by the second CEMS detection component (62), ppm.

10. A method for online removal of arsenic and selenium in a waste incineration power plant, characterized in that: A system according to any one of claims 1 to 9, comprising: The modified liquid is sprayed by the gas-liquid atomizing nozzle (17) so as to mix the modified liquid with the fly ash in the raw ash bin (11) in a gas-solid manner; The gas-solid mixed product is ground using the grinding chamber (12); The ground product is passed through the cyclone separator (13) under the influence of primary air, so that the solid phase product enters the modified ash bin (14) for storage; Under the action of the gas discharged from the cyclone separator (13) and the compressed air source (18), the gas is mixed with the modified ash in the modified ash bin (14) in the mixer (16), and the modified ash is injected into the tail flue of the waste incinerator (1) through the injector (19) to remove arsenic and selenium pollutants in the flue gas.

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