A method and apparatus for purifying waste incineration flue gas

Abstract

The application discloses a waste incineration flue gas purification method and equipment. The method comprises the following steps: receiving flue gas, spraying water for rapid cooling, and flowing the generated liquid mixture into a sedimentation tank; adding oxidizing gas to the flue gas, spraying water into the flue gas, and flowing the generated liquid mixture into the sedimentation tank; performing electrostatic dust and mist removal on the flue gas, flowing the collected liquid mixture into the sedimentation tank, and discharging the gas into the atmosphere; performing solid-liquid separation treatment on the liquid mixture in the sedimentation tank to obtain circulating water and solid precipitate, and recycling the circulating water; when the acid content of the circulating water exceeds a preset value, outputting the circulating water for post-treatment to prepare industrial mixed acid or / and industrial salt. The equipment comprises an air induction device, a rapid cooling tower, an absorption tower, an oxidizing gas generator, an electrostatic dust and mist remover, a sedimentation tank, a solid-liquid separation treatment device, a circulating device and a water treatment device which are connected through pipelines. The method has the characteristics of high efficiency, low cost, high benefit, energy saving and environmental protection, and the equipment has the characteristics of simple structure and low construction and operation cost.

Description

Technical Field

[0001] This invention belongs to the field of industrial flue gas treatment, and in particular relates to a method and equipment for purifying flue gas from waste incineration. Background Technology

[0002] The flue gas produced during waste incineration power generation contains a large amount of particulate matter (dust), heavy metals, and acidic gases (HCl, SO₂). x Pollutants such as NO2, HF, NO, and highly toxic organic pollutants (dioxins, furans, etc.) pose a serious threat to the atmospheric environment if they are not treated in a timely manner.

[0003] For environmental safety, the flue gas from waste incineration must meet certain purification requirements before it can be discharged. Many relevant standards, such as the Chinese national standard GB18485-2014 and the European Union standard 2000 / 76 / EC, have clearly stipulated the requirements for the discharged gases, such as the content of particulate matter, HCl, SO2, and NO. X The content of heavy metals and dioxins, etc.

[0004] The flue gas from waste incineration contains excessive amounts of acidic gases such as HCl and SO2. x To absorb and treat acidic components such as NO2, many mature flue gas treatment methods are available on the market, such as the dual-alkali method, wet ammonia method, dry / semi-dry method, SCR, etc. These methods all require the use of alkaline substances for neutralization. Most methods use milky or powdered lime, i.e., Ca(OH)2 or Mg(OH)2, or other alkaline powders or solutions to absorb the acidic components, thereby neutralizing them to form salts, which are then disposed of as fly ash. Fly ash also requires chelation and specialized landfill processes, which greatly increases treatment costs. Furthermore, when using lime treatment, the resulting calcium salts easily crystallize and precipitate, clogging pipes and equipment and causing equipment malfunctions.

[0005] Waste incineration plants typically employ a combined process of "SNCR + semi-dry + dry + activated carbon + bag filter". To meet increasingly stringent emission standards, higher-efficiency low-temperature SCR and wet denitrification processes are added on top of this. However, the operating temperature window of most developed low-temperature SCR catalysts is above 180℃. To match the catalyst's operating temperature, additional preheating / heat exchange devices are often required, which increases the operating cost of denitrification. Furthermore, SCR denitrification units have a large footprint and are complex systems, which further increases construction costs and system resistance, leading to a decrease in production safety. They are also unsuitable for retrofitting existing plants with compact layouts.

[0006] The current national standard for nitrogen oxide emissions is 250 mg / m³ per day. 3Given that many regions have set stricter emission standards for nitrogen oxides, the increase in emission standards will further increase the operating costs of waste incineration plants, putting enterprises under greater operational pressure.

[0007] In addition, dioxins and heavy metals in flue gas are difficult to remove efficiently in a very short time in the flue, and the treatment equipment is expensive. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a method for purifying flue gas from waste incineration that is highly efficient, low-cost, high-yield, energy-saving and environmentally friendly.

[0009] The further technical problem to be solved by the present invention is to provide a waste incineration wet flue gas purification device with simple structure, high degree of integration, and low construction and operation costs.

[0010] The technical invention adopted by this invention to solve its technical problem is: constructing a method for purifying flue gas from waste incineration, comprising the following steps:

[0011] S1. Receive flue gas from the waste incineration boiler;

[0012] S2. The flue gas is injected with water to rapidly cool it down, forming droplets. The liquid mixture generated by the rapid cooling is collected and flows into a sedimentation tank.

[0013] S3. Add oxidizing gas to the flue gas to oxidize the oxidizable components in the flue gas into water-soluble acidic components;

[0014] S4. After the oxidizing gas acts, water is sprayed into the flue gas to absorb or adsorb the acidic components and solid particles in the flue gas. The liquid mixture generated by absorption or adsorption is collected and flows into the sedimentation tank.

[0015] S5. Electrostatic dust removal and demisting are performed on the sprayed flue gas, and the liquid mixture formed by the adsorption of mist droplets flows into the sedimentation tank, while the gas is discharged into the atmosphere.

[0016] S6. After solid-liquid separation treatment of the liquid mixture collected in the sedimentation tank, circulating water and solid precipitate are obtained. The circulating water replaces the water in steps S2 and S4 for recycling.

[0017] S7. When the acid content in the circulating water in the sedimentation tank exceeds a preset value, at least a portion of the circulating water is output for post-treatment to produce industrial mixed acid and / or industrial salt, and water is added in at least one of steps S2, S4 and S6 to restore the absorption capacity of the circulating water.

[0018] Furthermore, in the waste incineration flue gas purification method, preferably in step S3, the oxidizing gas is at least chlorine dioxide, and the oxidizable components in the flue gas include at least sulfur dioxide and nitric oxide.

[0019] Furthermore, in the waste incineration flue gas purification method, preferably in step S2, the water injection rate per unit time is such that it rapidly cools the flue gas to 65-80°C within 4-9 seconds.

[0020] Furthermore, in the waste incineration flue gas purification method, preferably in step S4, the flue gas travels from bottom to top, the water is sprayed from top to bottom, and the liquid mixture obtained after spraying flows downward into the sedimentation tank.

[0021] Furthermore, in the aforementioned waste incineration flue gas purification method, preferably in step S4, a packing layer is provided in the flue gas travel direction. The packing layer is composed of stacked spherical packing with porous surfaces, wherein the porosity of the spherical packing is 80-92% and the specific surface area is 450-520 m². 2 / m 3 .

[0022] Furthermore, in the waste incineration flue gas purification method, it is preferable that in step S5, the electrostatic dust removal and demisting of the flue gas is performed using wet electrostatic dust removal.

[0023] Furthermore, in the waste incineration flue gas purification method, preferably in step S7, the acid content is calculated as hydrochloric acid, and the preset value is that the mass percentage concentration of hydrochloric acid in the circulating water reaches 5% to 20%.

[0024] Furthermore, in the waste incineration flue gas purification method, preferably in step S6, the solid-liquid separation treatment includes at least the steps of sedimentation, acid washing, and pressure filtration.

[0025] Furthermore, in the waste incineration flue gas purification method, preferably in step S7, the post-treatment includes membrane separation treatment, or / and the post-treatment includes neutralization precipitation, adsorption and / or filtration, evaporation treatment.

[0026] A waste incineration flue gas purification device includes the following components connected together via pipes:

[0027] An exhaust fan is used to propel the flue gas through the equipment;

[0028] A quench tower is used to receive flue gas and spray water into the flue gas to cool it down rapidly.

[0029] An oxidizing gas generator is used to generate oxidizing gases.

[0030] An absorption tower is provided with an air inlet for receiving flue gas and an inlet for receiving oxidizing gas on its lower side wall, and a spray nozzle for spraying water into the flue gas and an air outlet on its upper side wall or top surface, respectively.

[0031] Electrostatic precipitators and demisters are used to electrostatically remove dust and mist from the sprayed flue gas.

[0032] Sedimentation tanks are used to receive liquid mixtures flowing out of quench towers, absorption towers, and electrostatic precipitators and demisters.

[0033] A solid-liquid separation treatment device is used to separate liquid mixtures in a sedimentation tank to obtain circulating water;

[0034] A circulation device is used to send the circulating water in the sedimentation tank into the quench tower and the absorption tower for recycling;

[0035] A water treatment device that, when the acid content in the circulating water in the sedimentation tank exceeds a preset value, outputs at least a portion of the circulating water to be treated by the water treatment device to produce industrial mixed acid and / or industrial salt.

[0036] Furthermore, in the waste incineration flue gas purification equipment, the oxidizing gas generator is a composite chlorine dioxide gas generator, a high-purity chlorine dioxide gas generator, or an ozone generator, preferably a composite chlorine dioxide gas generator. The composite chlorine dioxide gas generator generates oxidizing gases ClO2 and Cl2, the high-purity chlorine dioxide gas generator generates oxidizing gas ClO2, and the ozone generator generates ozone.

[0037] Furthermore, in the waste incineration flue gas purification equipment, preferably, the middle part of the absorption tower is filled with a packing layer, the side wall below the packing layer is provided with an air inlet for receiving flue gas and an inlet for receiving oxidizing gas, and the side wall or top surface above the packing layer is respectively provided with a spray port for spraying water into the flue gas and an air outlet.

[0038] Furthermore, in the waste incineration flue gas purification equipment, the solid-liquid separation treatment device preferably includes at least a sedimentation tank, an acid washing tank, and a filter press.

[0039] Furthermore, in the waste incineration flue gas purification equipment, the water treatment device preferably includes a membrane separator; or / and the water treatment device includes a neutralization reaction sedimentation tank, an activated carbon adsorption tank, and an evaporator.

[0040] The implementation of this invention has the following beneficial effects:

[0041] The fundamental difference between this invention and traditional waste incineration flue gas purification methods is that traditional methods attempt to remove pollutants from flue gas within a few seconds in the flue, which is extremely difficult and requires a large amount of high-efficiency environmental protection consumables, resulting in high operating costs. This invention transfers pollutants in the flue gas to a liquid first, and then treats inorganic pollutants outside the flue without time constraints, which greatly improves the flue gas purification effect and saves a lot of flue gas purification costs.

[0042] 1. This invention only requires the simple use of low-cost water or recycled water in multiple steps to fully extract and transfer the acidic components in the flue gas into the water. In the entire flue gas treatment process, neither acid nor alkali needs to be added. The acidic components in the flue gas are directly absorbed and transformed, and the treated product is industrial mixed acid or industrial salt. This not only turns waste into treasure, but also has significant commercial value.

[0043] 2. Multiple treatment steps are in an acidic environment, which can be directly used to pickle solid particles in flue gas. The large amount of acidic liquid comes into full contact with the solid particles, making it easier to wash heavy metals and dioxins off the dispersed inorganic particles. The cleaning is more thorough. Compared with the existing technology of water washing fly ash (solid particles), it greatly improves the washing rate of heavy metals and dioxins in fly ash. The treatment method is simpler and more reliable, consumes less energy, and the post-treatment is very simple to achieve the harmless requirements.

[0044] 3. In this invention, solid-liquid separation is performed on the recovered liquid mixture at a relatively low cost, and heavy metals and toxic and harmful impurities are removed to obtain industrial mixed acid or industrial salt, thereby realizing the resource utilization of waste.

[0045] 4. Compared with traditional SCR, this invention has higher denitrification efficiency, lower operating temperature, lower construction cost, smaller footprint, does not increase system resistance, and is more flexible in layout, making it more suitable for the renovation of old plants.

[0046] 5. No alkaline substances are used as deacidifying agents throughout the entire flue gas purification process, saving operating costs.

[0047] 6. The entire flue gas purification process is energy-efficient, generates no pollutants again, and discharges no wastewater, making it energy-saving and environmentally friendly. Attached Figure Description

[0048] To more clearly illustrate the technical invention of this invention, the following description will be provided in conjunction with the accompanying drawings and embodiments. It should be understood that the following drawings only show certain embodiments of the invention and should not be considered as limiting the scope. Those skilled in the art can obtain other related drawings based on these drawings without any creative effort. In the drawings:

[0049] Figure 1This is a process flow diagram of the waste incineration flue gas purification method according to Embodiment 1 of the present invention;

[0050] Figure 2 This is a schematic diagram of the structure of the waste incineration flue gas purification device according to Embodiment 2 of the present invention;

[0051] Figure 3 This is a schematic diagram of the quench tower in Embodiment 2 of the present invention;

[0052] Figure 4 This is a schematic diagram of the absorption tower in Embodiment 2 of the present invention;

[0053] Figure 5 This is a process flow diagram of the production of industrial mixed acid using circulating water in Embodiment 2 of the present invention;

[0054] Figure 6 This is a process flow diagram of industrial salt production using circulating water in Embodiment 2 of the present invention.

[0055] The diagram shows the names corresponding to each label in Example 2:

[0056] 1. Quenching tower, 1-1 air inlet, 1-2 quenching nozzle, 1-3 air outlet, 1-4 liquid mixture discharge outlet, 2. Oxidizing gas generator, 13. Chlorine dioxide blower, 3. Absorption tower, 3-1 liquid mixture discharge outlet, 3-2 air inlet, 3-3 oxidizing gas inlet, 3-4 packing layer, 3-5 spray head, 3-6 air outlet, 4. Electrostatic dust collector and demister, 5. Exhaust fan, 6. Chimney, 7. Circulation device, 9. Solid-liquid separation treatment device, 9-1 sedimentation tank, 9-2 pickling tank, 9-3 plate and frame filter press, 10. Water treatment device, 10-1 membrane separator, 10-2 impurities, 10-3 industrial mixed acid, 10-4 neutralization sedimentation tank, 10-5 heavy metals, 10-6 activated carbon adsorption tank, 10-7 dioxins, 10-8 evaporator, 10-9 industrial salt, 10-10 cooling water. Detailed Implementation

[0057] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the invention will now be described in detail with reference to the accompanying drawings. In the following description, it should be understood that the orientations or positional relationships indicated by terms such as "front," "rear," "upper," "lower," "left," "right," "longitudinal," "horizontal," "vertical," "horizontal," "top," "bottom," "inner," "outer," "head," and "tail" are based on the orientations or positional relationships shown in the accompanying drawings, and are constructed and operated in a specific orientation. They are only for the convenience of describing the present invention and do not indicate that the device or element referred to must have a specific orientation; therefore, they should not be construed as limitations on the present invention.

[0058] It should also be noted that, unless otherwise explicitly specified and limited, terms such as "installation," "connection," "linking," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. When an component is referred to as being "on" or "below" another component, the component can be located "directly" or "indirectly" on the other component, or there may be one or more intermediary components. The terms "first," "second," "third," etc., are used only for the convenience of describing the present invention and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," etc., may explicitly or implicitly include one or more of that feature. For those skilled in the art, the specific meaning of the above terms in the present invention can be understood according to the specific circumstances.

[0059] Example 1, as Figure 1 As shown, a method for purifying flue gas from waste incineration includes the following steps:

[0060] S1. Receive flue gas from the waste incineration boiler. The received flue gas typically originates from the economizer outlet of the waste incineration boiler. The flue gas generated during waste-to-energy incineration contains a large amount of particulate matter (99% of which is non-combustible silicon-containing inorganic dust), heavy metals, acidic gases (HCl, NO2, SO2, HF, etc.), NO, and highly toxic organic pollutants (dioxins, furans, etc.). This flue gas cannot be directly discharged into the atmosphere and requires purification treatment before release. The flue gas temperature at waste incineration plants reaches 180–230℃, placing high demands on the performance of subsequent purification equipment. Therefore, the received flue gas needs to undergo a rapid cooling process.

[0061] S2. The flue gas is rapidly cooled by injecting water to form droplets. The liquid mixture generated by the rapid cooling is collected and flows into a sedimentation tank. Rapid cooling refers to cooling the flue gas flowing through the equipment in a short period of time. In this invention, atomized injection is used, where water directly forms droplets. This increases the contact area with the flue gas, promoting rapid cooling. Furthermore, rapid cooling also provides a preliminary treatment of the flue gas. Since the pollutants in the flue gas include high-temperature gases and solid particles, large-diameter solid particles (e.g., >5μm) are washed away by water and carried downstream by gravity. There are also a large number of solid particles with diameters in the range of 0.1–5μm. These solid particles can act as condensation nuclei. Under the condition of relative humidity supersaturation creating microspaces on the surface of the condensation nuclei, the sprayed droplets can spontaneously condense on them, generating dense water droplets with a certain particle size and suitable distribution. Simultaneously, easily soluble gases in the flue gas (such as SO2, NO2, HF, etc.) are encapsulated and dissolved by the droplets. After repeated collisions, the droplets containing the pollutants increase in surface area and gravity. Larger droplets containing pollutants fall under the influence of gravity, aggregate to form a liquid mixture, and are collected and flow into the sedimentation tank. Smaller droplets are carried away and flow with the flue gas to the next step of treatment.

[0062] In this step, water is used initially; it can be tap water, reclaimed water, or industrial water. Water-soluble substances in the flue gas include water-soluble solid particles and water-soluble gases, which can dissolve in the mist droplets. Subsequently, to save energy and reduce costs, treated circulating water from a sedimentation tank can be used for spray treatment of the flue gas.

[0063] In this step, the spray droplets absorb or adsorb existing water-soluble acidic components (water-soluble gases) and solid particulate matter in the flue gas. The removal rate of SO2 from the flue gas exceeds 80%, and the removal rate of HCl exceeds 95%, thus completing preliminary desulfurization and dechlorination. It also achieves preliminary dust removal, eliminating large dust particles. Furthermore, the spray and acidic environment cause at least some dioxins adsorbed on inorganic solid particles to be eluted from the inorganic solid particles and enter the liquid mixture. At least some heavy metals also react with the strong acid in the droplets to become heavy metal ions, dissolving in the liquid and flowing into the sedimentation tank.

[0064] In this step, the preferred water injection rate per unit time is sufficient to rapidly cool the flue gas, reducing its temperature to 65-80°C within 4-9 seconds. This amount ensures the flue gas is cooled as it passes through the quenching device, without requiring prolonged residence time, thus improving processing efficiency. Simultaneously, without affecting the flue gas flow rate and while meeting cooling requirements, it also maximizes the satisfaction of preliminary dust removal and dissolution of soluble gases in the flue gas. The specific location and number of water spray devices are designed according to actual needs and are not limited in this invention. Specific time requirements can be 4, 5, 6, 7, 8, or 9 seconds, and temperatures can be reduced to 65°C, 68°C, 70°C, 72°C, 75°C, 77°C, or 80°C, etc. All temperatures within this range are suitable for this invention.

[0065] Since rapid cooling requires reducing the temperature to below 100°C within a few seconds, in order to meet the rapid cooling speed requirements, the flue gas can be pre-cooled before water is injected for rapid cooling. This pre-cooling process can reduce the temperature from around 200°C to below 150°C, or even below 120°C or 100°C. The pre-cooling process can be performed using a heat exchanger. This pre-cooling process is not a necessary step. If water injection can meet the rapid cooling requirements, the pre-cooling process can be omitted.

[0066] Even after cooling, the flue gas still contains small-diameter solid particles and oxidizable pollutant gases, requiring further treatment.

[0067] S3. An oxidizing gas is added to the flue gas to oxidize the oxidizable components in the flue gas into water-soluble acidic components. Preferably, the oxidizing gas is at least chlorine dioxide, and the oxidizable components in the flue gas include at least sulfur dioxide and nitric oxide. The oxidizing gas most preferably used in this invention is ClO2 gas, but it may also contain Cl2, i.e., a mixture of ClO2 and Cl2.

[0068] The flue gas from waste incineration contains a large amount of NO, which is converted into NO2 under the action of oxidizing gases. NO2 then reacts with water to form nitric acid. The SO2 that was not treated in step S2 also reacts with water under the action of oxidizing gases to form sulfuric acid that is soluble in water.

[0069] S4. After the oxidizing gas acts, water is sprayed into the flue gas to absorb or adsorb the acidic components and solid particles in the flue gas. The liquid mixture generated by absorption or adsorption is collected and flows into the sedimentation tank.

[0070] Specifically, water can be used initially, such as tap water, reclaimed water, or industrial water. Subsequently, to save energy and reduce costs, treated circulating water from a sedimentation tank can be used to treat the flue gas. The acidic components resulting from the oxidation of the gases can be absorbed or adsorbed upon contact with water.

[0071] To ensure that the acidic components in the flue gas are absorbed and dissolved by water as much as possible, and that solid particles are carried away by the water, the flue gas travels from bottom to top, while water is sprayed from top to bottom. The resulting liquid mixture flows downward into a sedimentation tank. More preferably, a packing layer is provided along the flue gas travel direction. This packing layer is composed of stacked spherical packing material with porous surfaces, and gaps exist between the spherical packing materials. The porosity of the spherical packing material is 80–92%, and its specific surface area is 450–520 m² / m³. 3 The porosity can be selected from 80%, 82%, 85%, 87%, 90%, and 92%, and the specific surface area can be selected from 450 m² / m². 3 470㎡ / m 3 485㎡ / m 3 495㎡ / m 3 500㎡ / m 3 507㎡ / m 3 510㎡ / m 3 515㎡ / m 3 520㎡ / m 3 Within the aforementioned scope, the present invention is not limited. Water flows from top to bottom onto the surface of the spherical packing material, forming a water film. When flue gas passes through the packing layer from bottom to top, the acidic components formed by the oxidation reaction are easily soluble in water. The water-soluble acidic components contained in the gas and those generated by the reaction are absorbed into the water upon contact with the water film, forming an acidic liquid. This acidic liquid flows down and continuously washes the surface of the spherical packing material below. It can also carry pollutants (solid particles) from the flue gas and adsorbed on the surface of the spherical packing material away from the packing layer. Finally, the acidic liquid carrying the solid particles forms a liquid mixture, which is collected and flows into a sedimentation tank, thereby purifying the flue gas. The packing layer is not mandatory.

[0072] During the process of flue gas reacting with oxidizing gases and then being sprayed with water to form an aqueous solution, various oxidation reactions occur. Specifically, possible oxidation reactions include:

[0073] 2ClO2 + 5NO + H2O = 2HCl + 5NO2

[0074] 3NO2 + H2O = 2HNO3 + NO

[0075] 5SO₂ + 2ClO₂ + 6H₂O = 5H₂SO₄ + 2HCl

[0076] Cl₂ + NO + H₂O = NO₂ + 2HCl

[0077] As can be seen from the above, the acidic components in the products, such as HCl, HNO3, and H2SO4, are highly soluble in water. Once formed, they are quickly absorbed by the sprayed water and then flow away. The NO produced in the reaction will continue to be oxidized, eventually forming the corresponding acidic component (nitric acid), which is then absorbed by the water and carried away.

[0078] Flue gas contains not only gases, but also solid particles such as inorganic dust, and may also include liquids such as droplets or other chemical droplets. After being washed with water, some of these components will also flow into the liquid, becoming part of the liquid mixture.

[0079] S5. Electrostatic dust removal and demisting are performed on the flue gas after spraying. The liquid mixture formed by the adsorption of the mist droplets generated by spraying flows into the sedimentation tank, while the gas is discharged into the atmosphere.

[0080] The preceding steps have already intercepted most of the solid particulate matter, liquid, and gaseous pollutants into the liquid mixture and collected them in the sedimentation tank. The remaining small droplets and small-diameter solid particles adsorbed by the droplets are dealt with by electrostatic dust removal and demisting.

[0081] This step of electrostatic dust removal and demisting preferably uses a wet electrostatic dust removal method to remove the last small droplets and small-diameter solid particles. The electrostatic dust removal and demisting process causes the remaining droplets (containing acidic liquid and solid particles) to be adsorbed and form a liquid mixture that flows into the sedimentation tank.

[0082] After the above three steps of flue gas interception and treatment, the solid particulate matter, acidic gases and toxic and harmful substances in the flue gas can be basically transferred to water, and the flue gas can be discharged in a harmless manner.

[0083] The liquid mixture formed by the transfer to water contains strong acids, inorganic solid particles, dioxin particles, and heavy metal ions, which can be treated gradually, thoroughly, and at low cost, without being limited by time.

[0084] S6. After solid-liquid separation treatment of the liquid mixture collected in the sedimentation tank, circulating water and solid precipitate are obtained. The circulating water replaces the water in steps S2 and S4 for recycling. Specifically, the liquid mixture entering the sedimentation tank undergoes solid-liquid separation treatment, which includes at least sedimentation, acid washing, and pressure filtration steps. First, solid particles such as mud and dust are initially separated by sedimentation, and most of the liquid is separated out. The remaining liquid mixture then enters the acid washing step. The liquid mixture contains a small amount of liquid and solid particles (precipitate). Circulating water is added and stirred. In the previous steps, the liquid mixture is acidic, and the solid particles are essentially acid washed to remove impurities such as chlorides (including soluble chlorides and dioxins), heavy metals, and soluble salts. After acid washing with circulating water, the precipitate (fly ash) is further treated to remove harmful substances and dehydrated by pressure filtration to make mud cakes, which can be landfilled in sanitary landfills or further processed for resource utilization as building materials. The treated upper layer liquid can be used as circulating water for recycling.

[0085] S7. When the acid content in the circulating water in the sedimentation tank exceeds a preset value, at least a portion of the circulating water in the sedimentation tank is output after treatment to produce industrial mixed acid and / or industrial salt. The acid content is calculated as hydrochloric acid, and the preset value is a mass percentage concentration of hydrochloric acid in the circulating water of 5% to 20%.

[0086] When circulating water is used repeatedly a certain number of times and absorbs a certain amount of acidic substances, it gradually transforms from initial water into water with a certain concentration of acid, and its ability to absorb acid gradually decreases. When the acid content of the circulating water exceeds a preset value, the circulating water can no longer be used. A portion of the circulating water in the sedimentation tank needs to be discharged for treatment, and the remaining circulating water can be reduced in concentration before it can continue to be used as circulating water.

[0087] Since it is necessary to reduce the concentration of the circulating water in the sedimentation tank to restore its absorption capacity and to maintain sufficient circulating water in the sedimentation tank for use in steps S2 and S4, it is necessary to replenish the circulating water in the sedimentation tank. This replenishment can be done in at least one of steps S2, S4, and S6, with the goal of replenishing enough water for recycling.

[0088] For convenience, a preset value can be determined by selecting one acid, such as HCl, calculated as hydrochloric acid. The preset value is that the mass percentage concentration of hydrochloric acid in the circulating water reaches 5% to 20%. When the mass percentage concentration of HCl in the circulating water of the sedimentation tank reaches 5%, 8%, 10%, 12%, 15%, 17%, 19%, 20%, etc., at least a portion of the circulating water is discharged for treatment. In addition to hydrochloric acid, the total acid content, sulfuric acid, or nitric acid can also be used as the preset value; all are applicable to this invention.

[0089] In this step, one method of treating circulating water is membrane separation. By using membrane separation, heavy metal ions, dioxins, and other substances in the circulating water can be further separated to obtain industrial mixed acid. There are various specific methods of membrane separation, and existing membrane separation technologies can be used, which will not be elaborated here.

[0090] Another treatment method involves neutralizing, precipitating, adsorbing, and evaporating the discharged circulating water to obtain industrial salt. First, alkali is added for neutralization to create a salt solution. Then, coagulants and flocculants are added to precipitate heavy metals. Next, activated carbon is used to adsorb dioxins. Finally, the water is evaporated to obtain industrial salt. The evaporated water is cooled and used as makeup water in a sedimentation tank. Neutralization, precipitation, adsorption, and evaporation can be performed using existing technologies, which will not be elaborated upon here.

[0091] Example 2, as Figure 2 As shown, a waste incineration flue gas purification device includes the following devices connected together by pipes:

[0092] The exhaust fan 5 is used to drive the flue gas to flow in the equipment;

[0093] Quenching tower 1 is used to receive flue gas and spray water into the flue gas to rapidly cool it down.

[0094] Oxidizing gas generator 2 is used to generate oxidizing gas;

[0095] The absorption tower 3 has an air inlet for receiving flue gas and an inlet for receiving oxidizing gas on the lower side wall, and a spray head for spraying water into the flue gas and an air outlet on the upper side wall and / or top surface, respectively.

[0096] Electrostatic precipitator 4 is used to perform electrostatic dust removal and demisting on the sprayed flue gas.

[0097] Solid-liquid separation treatment device 9 is used to separate the liquid mixture in sedimentation tank 9-1 to obtain circulating water;

[0098] Sedimentation tank 9-1 is used to receive the liquid mixture flowing out of quench tower 1, absorption tower 3, and electrostatic precipitator demister 4;

[0099] The circulation device 7 is used to send the circulating water into the quench tower 1 and the absorption tower 3 for recycling.

[0100] The water treatment device 10, when the acid content in the circulating water in the sedimentation tank 9-1 exceeds a preset value, outputs at least a portion of the circulating water to be treated by the water treatment device to produce industrial mixed acid and / or industrial salt.

[0101] All of the above-mentioned components are connected by pipes. The exhaust fan 5 is located at the rear of the entire equipment and is connected to the chimney 6 that is discharged into the atmosphere. The exhaust fan 5 is an exhaust fan installed on the pipe.

[0102] like Figure 2 , 3 As shown, the quench tower 1 is a cylindrical structure with an air inlet 1-1 at its upper or top, connected to the economizer outlet of the waste incineration boiler via a pipe to receive flue gas from the economizer outlet. The bottom or lower side wall of the quench tower 1 has a flue gas outlet 1-3, which is connected to the absorption tower 3 via a pipe. Furthermore, the top of the quench tower 1 is equipped with a water spray device with quench nozzles 1-2. Multiple quench nozzles 1-2 are evenly arranged in various patterns, such as rings or meshes, to cover all parts of the quench tower 1, ensuring that the incoming flue gas is cooled by water spray. The multiple quench nozzles 1-2 are connected via pipes for unified control.

[0103] Water is sprayed from the quench nozzles 1-2, forming liquid droplets. As the flue gas flows from top to bottom and the water is sprayed from top to bottom, the flue gas is cooled. The bottom of the quench tower 1 has a conical structure, and the liquid mixture outlet 1-4 is located at the tip of the cone, which facilitates the discharge of all liquid mixture in the quench tower 1. The liquid mixture flows into the sedimentation tank 9-1 through a pipe.

[0104] The initial spray uses water, such as tap water, reclaimed water, or industrial water. The liquid mixture flows into sedimentation tank 9-1, where it undergoes solid-liquid separation. The liquid then becomes circulating water and is sent back to quench tower 1 for spray cooling. The water used subsequently can be tap water, reclaimed water, or industrial water, which is then recycled and reused.

[0105] The quench tower 1 sprays water through quench nozzles 1-2, forming a large number of droplets. In addition to its rapid cooling function, it also absorbs water-soluble components, especially easily soluble gases (such as HCl, SO2, NO2, HF, etc.) and removes dust. When the flue gas enters from the top or upper part of the tower, it comes into contact with the droplets sprayed from the quench tower 1. After contact, easily soluble gases, solid particles, and other pollutants in the flue gas are encapsulated or washed away by the droplets. The droplets encapsulating pollutants increase in surface area and gravity after further collisions. Larger droplets encapsulating pollutants fall to the bottom of the quench tower 1 under the influence of gravity, forming a liquid mixture. Large solid particles also fall to the bottom of the quench tower 1 under the washing of the droplets; smaller droplets are carried away and flow with the flue gas.

[0106] The quench tower 1 simulates the natural fog formation mechanism, using solid particles in the flue gas as condensation nuclei. The quench tower uses physicochemical effects to create a relative humidity supersaturation condition in the microspace on the surface of the condensation nuclei, causing the droplets sprayed from the nozzle to spontaneously condense on them, generating dense water droplets with a certain particle size and appropriate distribution.

[0107] The cooled flue gas will enter absorption tower 3, where it will undergo two treatment processes:

[0108] First, it reacts with the introduced oxidizing gas to oxidize the oxidizable components in the flue gas that can react with the oxidizing gas into soluble acidic components; second, it sprays water into the flue gas to absorb the soluble acidic components and solid particulate matter in the flue gas.

[0109] like Figure 2 , 4 As shown, the absorption tower 3 is also a cylindrical structure. Its lower sidewall has an inlet 3-2 and an oxidizing gas inlet 3-3 for receiving oxidizing gases. The inlet 3-2 is connected to the flue gas outlet 1-3 of the quench tower 1 via a pipe, receiving flue gas from the quench tower 1. The oxidizing gas inlet 3-3 is connected to the oxidizing gas generator 2 via a pipe. The flue gas inside the absorption tower 3 flows upwards and is discharged from the outlet 3-6 on the top sidewall through a pipe to the electrostatic precipitator and demister 4. The inlet 3-2 and the oxidizing gas inlet 3-3 can be arranged side-by-side, or the oxidizing gas inlet 3-3 can be located within or connected to the inlet 3-2, allowing the flue gas and oxidizing gas to mix and react.

[0110] The oxidizing gas generator 2 can be a composite chlorine dioxide gas generator, a high-purity chlorine dioxide gas generator, or an ozone generator. The composite chlorine dioxide gas generator produces oxidizing gases ClO2 and Cl2, the high-purity chlorine dioxide gas generator produces oxidizing gas ClO2, and the ozone generator produces ozone. Since the production cost of high-purity chlorine dioxide gas generators and ozone generators is relatively high, the present invention preferably uses a composite chlorine dioxide gas generator.

[0111] Specifically, ClO2 and Cl2 generated by the composite chlorine dioxide gas generator are blown into the oxidizing gas inlet 3-3 by the chlorine dioxide blower 13. They mix with the rapidly cooled flue gas entering through the inlet 3-2, undergoing an oxidation reaction. The resulting mixture enters the absorption tower 3 through the inlet 3-2 on the bottom side wall. Simultaneously, the top of the absorption tower 3 is equipped with spray heads 3-5, from which water is sprayed downwards. Water is used initially, and subsequently, recycled water can be used. The spraying further lowers the temperature of the flue gas. After the water is sprayed down, the acidic components formed after the oxidation reaction are easily soluble in water and are absorbed. Additionally, water-soluble components in the flue gas that were not absorbed by water in the quench tower 1 are further absorbed by water in the absorption tower 3. The oxidation reaction also produces some water-soluble components (such as NO2), which are also absorbed by water. Of course, these acidic components are all water-soluble. However, some products or components in the flue gas may be neutral, such as inorganic solid particles, which can be removed from the flue gas by washing or adsorption with water, thus purifying the flue gas. The liquid mixture containing these components flows from top to bottom through the absorption tower 3, exiting from the liquid mixture outlet 3-1, and then enters the sedimentation tank 9-1 through a pipe. The lower part of the absorption tower 3 also has a conical structure, with the liquid mixture outlet 3-1 located at the apex of the cone.

[0112] The acidic components in the above products, such as HCl, HNO3, and H2SO4, are highly soluble in water. Once formed, they are quickly absorbed by the sprayed water and then flow away. The NO produced in the reaction will continue to be oxidized, generating corresponding acidic components which are then absorbed by the water and carried away, and ultimately, the vast majority of them are consumed.

[0113] To ensure that the flue gas is fully absorbed and dissolved by water and oxidizing gases within absorption tower 3, such as... Figure 4 As shown, the absorber tower 3 of the present invention is preferably filled with a thick packing layer 3-4, with a total height of 2.5 to 4 meters. The packing layer 3-4 is composed of stacked spherical packing. There are gaps between the spherical packing. Water or circulating water flows from top to bottom onto the surface of the spherical packing to form a water film. Flue gas and oxidizing gas enter from the lower air inlet 3-2 and oxidizing gas inlet 3-3 of the absorber tower 3, respectively. When passing through the packing layer 3-4 from bottom to top, the acidic components contained therein and generated by the reaction are absorbed into the water when in contact with the water film. The water flows down and continuously washes the surface of the spherical packing. It can also carry away pollutants such as solid particles adsorbed on the surface of the spherical packing from the packing layer 3-4 and flow into the liquid mixture outlet 3-1 for discharge.

[0114] The spherical packing in packing layers 3-4 can be made of materials such as PP and PVDF, with a multi-faceted hollow sphere structure being preferred. This offers advantages such as high gas velocity, numerous blades, low resistance, large specific surface area, effective gas-liquid exchange, and high operational flexibility. The preferred porosity of the spherical packing is 80–92%, and the specific surface area is 450–520 m² / m². 3 The present invention is applicable to spherical fillers within the above-mentioned porosity and specific surface area ranges, and any filler within the above range can be selected.

[0115] In this embodiment, both oxidation and absorption steps are carried out in absorption tower 3. However, these two steps can obviously be carried out in two separate devices. For example, the cooled flue gas can first pass through an oxidation device, causing the oxidizable components to react with oxidizing gases, and then enter absorption tower 3 together, where the effective components are absorbed by water. That is, the present invention can simultaneously set up an oxidation device and an absorption tower, which are connected by pipelines.

[0116] In addition, the flue gas contains not only gases, but also solid particles such as dust, and may also contain liquids such as droplets or other chemical droplets. After being washed by the droplets in quench tower 1 and absorption tower 3, a large portion of these components will also flow into the liquid mixture.

[0117] After being sprayed and absorbed by the absorption tower 3, the flue gas is transported through the pipeline to the electrostatic precipitator 4. After being precipitated and demisted by the electrostatic precipitator 4, it is drawn into the chimney 6 through the induced draft device 5 and discharged into the atmosphere. The electrostatic precipitator process causes the mist droplets to be adsorbed and form a liquid mixture that flows into the sedimentation tank 9-1 through the pipeline.

[0118] The liquid mixture undergoes solid-liquid separation treatment via solid-liquid separation device 9. This separation process includes at least sedimentation, acid washing, and pressure filtration to separate solid particles such as mud and dust. The separated liquid is then reused as circulating water via circulation device 7. Circulation device 7 consists of two circulation pumps, each installed on a separate pipeline. The circulating water then re-enters the quench tower 1 and absorption tower 3 for reuse.

[0119] Specifically, the solid-liquid separation device 9 includes a sedimentation tank 9-1, an acid washing tank 9-2, a plate and frame filter press 9-3, etc.

[0120] First, sedimentation tank 9-1 can be a horizontal flow sedimentation tank, where the liquid mixture first passes through sedimentation tank 9-1 to deposit solid particles such as mud and dust. Of course, other types of sedimentation tanks can also be used, and this invention does not impose any restrictions.

[0121] After passing through sedimentation tank 9-1, the liquid mixture will enter acid washing tank 9-2, where it will be acid washed with circulating water containing acidic components. Then, it will be separated from the sludge containing impurities by plate and frame filter press 9-3 to form sludge cakes, and the liquid will return to sedimentation tank 9-1.

[0122] After the above treatment, the solid particles in the liquid mixture are separated out, forming mud cakes. After further processing, these mud cakes can meet the standards for building material applications, thus enabling waste recycling.

[0123] The water treatment device 10 includes a membrane separator 10-1; or / and the water treatment device 10 includes a neutralization reaction sedimentation tank 10-4, an adsorption tank 10-6, and an evaporator 10-8, wherein the membrane separator is used to prepare industrial mixed acid, and the neutralization reaction sedimentation tank, adsorption tank, and evaporator are used to prepare industrial salt. Either one can be selected, or both can be installed simultaneously.

[0124] like Figure 5 As shown, in one embodiment of the water treatment device 10, the discharged circulating water passes through a membrane separator 10-1, thereby filtering out impurities 10-2, such as dioxins and heavy metal ions, to obtain an industrial mixed acid 10-3. The membrane separator 10-1 can be a diffusion dialysis unit or other membrane separators capable of separating dioxins and heavy metal ions, and is not limited here.

[0125] In another embodiment of the water treatment device 10, such as Figure 6 As shown, the discharged circulating water is treated by water treatment device 10. First, it passes through neutralization sedimentation tank 10-4 to precipitate heavy metals 10-5 (first neutralization with alkali, then addition of coagulant and flocculant to precipitate heavy metals). Then, it passes through adsorption tank 10-6 to adsorb dioxins 10-7. Adsorption tank 10-6 is preferably an activated carbon adsorption tank, but other adsorption tanks can also be used. Then, it passes through evaporator 10-8 to obtain industrial salt 10-9 that meets the requirements. The evaporated water is cooled to form cooling water 10-10, which can be recycled back into sedimentation tank 9-1, quench tower 1, and / or absorption tower 3. Therefore, this system has no wastewater discharge and is very environmentally friendly.

[0126] The following practical case illustrates the practical significance of this invention. As is well known, the flue gas purification process in waste-to-energy plants has significant flaws. Existing technologies attempt to directly clean flue gas within a short 50-meter flue in a matter of seconds, which is extremely difficult and costly. This invention, however, transfers pollutants from the flue gas to water at low cost. Using a simple water treatment technology with minimal and inexpensive consumables, the treatment cost is reduced by approximately 60% in just a few hours. Furthermore, this invention comprehensively treats particulate matter, heavy metals, dioxins, acidic components, and nitrogen oxides. Due to its low operating resistance and low energy consumption, this method has achieved a significant increase in power generation of approximately 10% in actual operation of waste-to-energy plants.

[0127] We can intuitively compare the present invention with traditional processes through data, which shows the significant cost advantages and purification capabilities of the present invention.

[0128] In a pilot project, the flue gas purification equipment of this invention, after operation, reduced treatment costs by 60% compared to traditional alkali neutralization methods, increased power generation by 10%, and reduced fly ash to 0.03% of the original amount. In particular, the flue gas emissions after implementing this invention are significantly lower than EU standards by 1-2 orders of magnitude, especially the dioxin emission value (0.006 ng TEQ / Nm³). 3 The concentration of nitrogen oxides is already close to the detection limit of existing testing instruments. Secondly, the concentration of nitrogen oxide emissions is far below the national ultra-low emission standards; under controlled operating costs, it is entirely possible to control it to 10 mg / m³. 3 Within this range. The high standards of this invention can help waste incineration companies effectively avoid legal and corresponding financial risks. See the table below for details:

[0129]

[0130] The use of this invention and equipment to purify flue gas and obtain industrial mixed acid offers a cost advantage far exceeding that of traditional flue gas purification methods. This is exemplified by a single unit with a daily waste processing capacity of 600 tons and a flue gas emission flow rate of 120,000 Nm³. 3 Taking / h (the mainstream furnace type in the market) as an example, the cost comparison is shown in the table below:

[0131]

[0132]

[0133] The comparison results in the table above show that, compared to existing processes, the operating cost of this invention is reduced by approximately RMB 11.97 million, a decrease of about 61%. Considering the combined effect of increased power generation and reduced waste disposal fees, the overall net cost reduction is approximately RMB 18.67 million, a decrease of about 95%. Note the cost savings and significant social value brought about by the reduction in fly ash shown in the table. Regarding power generation, because the method and equipment of this invention have system operating resistance that is only 2 / 5 of that of existing processes, the power consumption of the induced draft fan can be reduced by about 10%, and the power generation from waste incineration can be increased by 10%. The increased revenue for incineration companies is essentially profit.

[0134] In summary, by employing this invention, from the moment the flue gas from the economizer outlet of the waste incineration boiler is received until it is finally discharged into the atmosphere, and throughout the entire gas path, including the cooling and spraying processes, no acids such as hydrochloric acid or nitric acid are added to the equipment, nor are alkaline substances such as calcium hydroxide, alkali, or limestone added. The entire process relies solely on the strong oxidation of oxidizing gases and the absorption by water spraying to convert oxidizable gases in the flue gas into water-soluble acidic components, which then leave the flue gas and enter the water body. Finally, through solid-liquid separation to remove impurities, industrial-grade mixed acid is obtained, thus achieving waste resource recovery. Therefore, the entire flue gas purification process is virtually ash-free, offering a significant cost advantage compared to currently popular flue gas purification technologies both internationally and domestically. Meanwhile, as a byproduct of flue gas purification, flue gas treatment manufacturers can produce this industrial mixed acid and industrial salt with only a small amount of additional cost. Therefore, the industrial mixed acid can be sold or transferred to some enterprises such as steel mills, sewage treatment plants, and textile printing and dyeing plants at low cost or even no cost as raw materials or consumables for pickling or pH neutralization. Furthermore, the industrial salt can also be utilized in industry, thus turning waste into treasure, achieving mutual benefit and win-win results, and jointly contributing to environmental protection.

[0135] It is understood that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. Therefore, all equivalent transformations and modifications made with respect to the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for purifying flue gas from waste incineration, characterized in that, Includes the following steps: S1. Receive flue gas from the waste incineration boiler; S2. The flue gas is injected with water to rapidly cool it down, forming droplets. The liquid mixture generated by the rapid cooling is collected and flows into a sedimentation tank. S3. Add an oxidizing gas to the flue gas to oxidize the oxidizable components in the flue gas into water-soluble acidic components; the oxidizing gas is at least chlorine dioxide, and the oxidizable components in the flue gas include at least sulfur dioxide and nitric oxide; S4. After the oxidizing gas acts, water is sprayed into the flue gas to absorb or adsorb the acidic components and solid particles in the flue gas. The liquid mixture generated by absorption or adsorption is collected and flows into the sedimentation tank. S5. Electrostatic dust removal and demisting are performed on the sprayed flue gas, and the liquid mixture formed by the adsorption of mist droplets flows into the sedimentation tank, while the gas is discharged into the atmosphere. S6. After solid-liquid separation treatment of the liquid mixture collected in the sedimentation tank, circulating water and solid precipitate are obtained. The circulating water replaces the water in steps S2 and S4 for recycling. S7. When the acid content in the circulating water in the sedimentation tank exceeds a preset value, at least a portion of the circulating water is output for post-treatment to produce industrial mixed acid and / or industrial salt, and water is added in at least one of steps S2, S4 and S6 to restore the absorption capacity of the circulating water.

2. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S2, before injecting water into the flue gas for rapid cooling, the flue gas is first pre-cooled.

3. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S2, the water injection rate per unit time is sufficient to rapidly cool the flue gas, reducing its temperature to 65-80°C within 4-9 seconds.

4. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S4, the flue gas moves from bottom to top, and the water is sprayed from top to bottom. The resulting liquid mixture flows downward into the sedimentation tank.

5. The method for purifying flue gas from waste incineration according to claim 4, characterized in that, In step S4, a packing layer is provided in the flue gas travel direction. The packing layer is composed of stacked spherical packing with porous surfaces. The porosity of the spherical packing is 80-92%, and the specific surface area is 450-520 m². 2 / m³.

6. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S5, the electrostatic dust removal and demisting of the flue gas are performed using wet electrostatic dust removal.

7. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S7, the acid content is calculated as hydrochloric acid, and the preset value is that the mass percentage concentration of hydrochloric acid in the circulating water reaches 5% to 20%.

8. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S6, the solid-liquid separation process includes at least precipitation, acid washing, and pressure filtration steps.

9. The method for purifying flue gas from waste incineration according to claim 1, characterized in that, In step S7, the post-processing includes membrane separation, or / and the post-processing includes neutralization precipitation, adsorption and / or filtration, evaporation.

10. A waste incineration flue gas purification device, applied to the waste incineration flue gas purification method according to any one of claims 1-9, characterized in that, This includes the following devices connected together by pipes: An exhaust fan is used to propel the flue gas through the equipment; A quench tower is used to receive flue gas and spray water into the flue gas to cool it down rapidly. An oxidizing gas generator is used to generate oxidizing gases. An absorption tower is provided with an air inlet for receiving flue gas and an inlet for receiving oxidizing gas on its lower side wall, and a spray nozzle for spraying water into the flue gas and an air outlet on its upper side wall and / or top surface, respectively. Electrostatic precipitators and demisters are used to electrostatically remove dust and mist from the sprayed flue gas. Sedimentation tanks are used to receive liquid mixtures flowing out of quench towers, absorption towers, and electrostatic precipitators and demisters. A solid-liquid separation treatment device is used to separate liquid mixtures in a sedimentation tank to obtain circulating water; A circulation device is used to send the circulating water in the sedimentation tank into the quench tower and the absorption tower for recycling; A water treatment device that, when the acid content in the circulating water in the sedimentation tank exceeds a preset value, outputs at least a portion of the circulating water for post-treatment to produce industrial mixed acid and / or industrial salt.

11. The waste incineration flue gas purification equipment according to claim 10, characterized in that, The oxidizing gas generator is a composite chlorine dioxide gas generator, a high-purity chlorine dioxide gas generator, or an ozone generator. The composite chlorine dioxide gas generator produces oxidizing gases ClO2 and Cl2, the high-purity chlorine dioxide gas generator produces oxidizing gas ClO2, and the ozone generator produces ozone.

12. The waste incineration flue gas purification equipment according to claim 10, characterized in that, The absorption tower is filled with a packing layer in the middle. The side wall below the packing layer is provided with an air inlet for receiving flue gas and an inlet for receiving oxidizing gas. The side wall and / or top surface above the packing layer are respectively provided with a spray nozzle for spraying water into the flue gas and an air outlet.

13. The waste incineration flue gas purification equipment according to claim 10, characterized in that, The solid-liquid separation treatment device includes at least a sedimentation tank, an acid washing tank, and a filter press.

14. The waste incineration flue gas purification equipment according to claim 10, characterized in that, The water treatment device includes a membrane separator; or / and the water treatment device includes a neutralization reaction sedimentation tank, an adsorption tank, and an evaporator.

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