Online fly ash hydrothermal degradation and resource treatment system for waste incineration power plant

Abstract

The utility model belongs to the field of chemical engineering and environmental protection, and particularly relates to an online fly ash hydrothermal degradation and recycling treatment system for a waste incineration power plant, which comprises a hydrothermal degradation device, a washing device, an adjusting device and an evaporative crystallization device, an outlet of the hydrothermal degradation device is connected with an inlet of the washing device, a washing liquid outlet and a wet ash outlet are formed in the washing device, the washing liquid outlet is connected with the adjusting device, and an outlet of the adjusting device is connected with the evaporative crystallization device; and the hydrothermal degradation device and the evaporative crystallization device are both connected with a waste heat boiler or a waste heat power generation system in the waste incineration power plant. According to the fly ash harmless treatment system, surplus heat energy and electric energy in the waste incineration power plant can be fully utilized, all fly ash harmless treatment procedures can be completed in the household waste incineration power plant, meanwhile, industrial chlorine salt and building material resources can be produced by utilizing soluble salt in fly ash, and the effects of reducing cost and improving benefits on the whole are achieved.

Description

Technical Field

[0001] The utility model belongs to the fields of chemical engineering and environmental protection, and particularly relates to an on-line hydrothermal degradation and resource utilization system for fly ash in a waste incineration power plant. Background Art

[0002] The fly ash generated by incinerating domestic waste accounts for about 3% - 5% of the total incineration volume, which is enriched with highly concentrated heavy metals, dioxins, chlorine elements, sulfur elements and other toxic and harmful substances.

[0003] In the past, domestic waste incineration power plants mainly adopted the disposal method of stabilizing and then landfilling, often requiring the addition of a large amount of agents such as cement, increasing the storage capacity pressure of the landfill. Moreover, the entire disposal process requires multiple cumbersome management procedures for incoming and outgoing bills, with high disposal costs and unable to achieve the complete harmless disposal and resource utilization of fly ash. Moreover, affected by policy guidance, this fly ash treatment method of stabilizing and then landfilling has been gradually abandoned.

[0004] The method for hydrothermally harmlessly treating waste incineration fly ash disclosed in the Chinese patent with the authorization announcement number CN111672876B uses an atmospheric pressure hydrothermal reaction to stabilize heavy metals in fly ash, and uses a microwave high-pressure hydrothermal reaction to further stabilize heavy metals in fly ash and degrade polycyclic aromatic hydrocarbons, with significant advantages such as high efficiency and environmental protection. Under hydrothermal conditions, the solvent in the subcritical or critical state has extremely strong oxidizing properties, can quickly fuse with organic substances such as dioxins, and greatly increases the solubility of dioxins in water under high temperature and high pressure, improving the reaction activity, thereby effectively promoting the decomposition of dioxins. After hydrothermal treatment, the fly ash not only has a significantly reduced dioxin concentration, but also the heavy metals in the fly ash exist as salts with a stable structure, reducing the leaching toxicity of heavy metals and contributing to the solidification of heavy metals in fly ash.

[0005] The hydrothermal degradation of fly ash needs to be carried out under high temperature and high pressure. At the same time, there is a large amount of surplus heat energy and electric energy in the waste incineration power plant. However, in the above patent, an additional heater is used as the heating source, and the surplus heat energy and electric energy in the waste incineration power plant are not utilized, which is a waste of existing energy and there is room for improvement.

[0006] Moreover, fly ash is enriched with toxic and harmful substances such as dioxins, heavy metals, sulfur elements and chlorine elements. Dioxins are carcinogenic substances, the content of heavy metals in fly ash is relatively high, and sulfur elements and chlorine elements are easily soluble in water to cause acid rain. These harmful substances will seriously endanger the natural environment and human health. However, the above patent only treats heavy metals and polycyclic aromatic hydrocarbons in fly ash, and cannot completely complete the harmless disposal of fly ash in the waste incineration power plant, nor does it treat and utilize the resources such as silicon, calcium, aluminum, magnesium, etc. contained in fly ash that can be used as raw materials for building materials production. Content of the Utility Model

[0007] The utility model provides an on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant, so as to solve the technical problems of insufficient energy and resource utilization and energy and resource waste existing in the existing fly ash treatment technologies.

[0008] To solve the above problems, the on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant provided by the utility model adopts the following technical solutions:

[0009] The on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant includes a hydrothermal degradation device, a water washing device, an adjusting device and an evaporation and crystallization device; the outlet of the hydrothermal degradation device is connected to the inlet of the water washing device, and the hydrothermal degradation device is used to be connected to a waste heat boiler or a waste heat power generation system in the waste incineration power plant to degrade dioxins in the fly ash and solidify heavy metals in the fly ash; the water washing device is used to extract soluble salts in the fly ash, further solidify calcium ions and heavy metals in the fly ash, and separate out washing liquid and wet ash, and the water washing device is provided with a washing liquid outlet and a wet ash outlet; the washing liquid outlet is connected to the adjusting device; the adjusting device is used to adjust the pH value of the washing liquid and further precipitate and filter suspended substances in the washing liquid, and the outlet of the adjusting device is connected to the evaporation and crystallization device; the evaporation and crystallization device is connected to the waste heat boiler or the waste heat power generation system, and is used to evaporate and crystallize the washing liquid with the adjusted pH value and separate out sodium chloride and potassium chloride.

[0010] Further, the water washing device includes a solid-liquid separation unit, and the solid-liquid separation unit adopts one of a pressure filtration separation device, a vertical centrifugal separation device and a horizontal screw centrifugal separation device.

[0011] Further, the water washing device is provided with multiple stages, and each stage of the water washing device is also provided with a washing liquid inlet. The washing liquid outlet of the lower-stage water washing device is connected to the washing liquid inlet of the upper-stage water washing device, the wet ash outlet of the upper-stage water washing device is connected to the inlet of the lower-stage water washing device, the washing liquid outlet of the first-stage water washing device is connected to the adjusting device, and the wet ash outlet of the last-stage water washing device is used to be connected to a device for resource utilization of the wet ash.

[0012] Further, the evaporation and crystallization device is provided with a condensed water outlet, and a first condensed water pipeline for introducing condensed water into the hydrothermal degradation device is connected between the condensed water outlet and the hydrothermal degradation device.

[0013] Further, a second condensed water pipeline for introducing condensed water into the last-stage water washing device is connected between the condensed water outlet and the last-stage water washing device.

[0014] Furthermore, the hydrothermal degradation device is connected with a first chemical agent adding device, which is used to add an alkaline solution, hydrogen peroxide and an iron ion solution into the hydrothermal degradation device. The alkaline solution is one or a combination of sodium hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate solutions.

[0015] Furthermore, the water washing device is connected with a second chemical agent adding device, which is used to add one or a combination of sodium carbonate, sodium phosphate, and sodium sulfate solutions into the water washing device.

[0016] Furthermore, the evaporation and crystallization device is one of a multi-effect evaporator and an MVR evaporator.

[0017] The beneficial effects of the present utility model are as follows:

[0018] 1. The surplus heat energy of the domestic waste incineration power plant is fully utilized to provide heat energy for the hydrothermal degradation device and the evaporation and crystallization device, without using an additional heater as the heating source, saving energy and avoiding energy waste. At the same time, the condensed water generated by the evaporation and crystallization device enters the hydrothermal degradation device and the water washing device respectively through the first condensed water pipeline and the second condensed water pipeline, realizing the repeated recycling of water resources within the system and improving the utilization rate of water resources.

[0019] 2. The fly ash can complete all the harmless treatment processes in the domestic waste incineration power plant. Dioxins in the fly ash are degraded under the strong oxidizing conditions in the hydrothermal degradation device, and heavy metals are solidified under the alkaline conditions in the hydrothermal degradation device. Resources such as silicon, calcium, aluminum, and magnesium that can be used as raw materials for building materials production are separated into wet ash through the water washing device, and chlorine elements are separated into the washing liquid through the water washing device and further obtain sodium chloride and potassium chloride through the evaporation and crystallization device. There is no need to go through cumbersome factory procedures and then carry out subsequent treatment procedures outside the factory, reducing the time cost, operation cost, and transportation cost of fly ash disposal. Moreover, the by-products obtained after treatment can be sold, improving the operating efficiency of the domestic waste incineration power plant.

[0020] 3. The water washing device has multiple stages, which are used to extract the soluble salts in the fly ash, further solidify the calcium ions and heavy metals in the fly ash, and separate the washing liquid and the wet ash. The separated wet ash enters the next-stage water washing device, which can fully dissolve the chlorine ions in the fly ash, facilitating the next-step resource treatment of the wet ash and avoiding the high chlorine element content in the building materials resources made from the wet ash, which is corrosive and not durable. Moreover, the cascade utilization of the washing liquid can effectively save the water consumption during the fly ash water washing process. Description of the Drawings

[0021] By reading the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present utility model will become readily understandable. In the drawings, several embodiments of the present utility model are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0022] Figure 1 is a flowchart of an on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant;

[0023] Figure 2 is a schematic connection diagram of a water washing device, a hydrothermal degradation device, and an adjustment device.

[0024] Description of reference numerals:

[0025] 1. Hydrothermal degradation device; 2. Water washing device; 3. Adjustment device; 4. Evaporation and crystallization device; 5. First-stage water washing device; 6. Second-stage water washing device; 7. Third-stage water washing device; 8. First condensate pipeline; 9. Second condensate pipeline. Detailed implementation manners

[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Those skilled in the art should know that the embodiments described below are a part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present utility model.

[0027] Embodiment 1 of the on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant provided by the present utility model:

[0028] As Figure 1 shown, the on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant includes a hydrothermal degradation device 1, a water washing device 2, an adjustment device 3, and an evaporation and crystallization device 4.

[0029] The hydrothermal degradation device 1 is connected to a first chemical agent adding device and is connected to a waste heat boiler or a waste heat power generation system in the waste incineration power plant. The first chemical agent adding device is used to add a first chemical agent into the hydrothermal degradation device 1, and the first chemical agent is a sodium hydroxide solution, hydrogen peroxide, and a ferric chloride solution. Of course, in other embodiments, the sodium hydroxide solution in the first chemical agent can be replaced by one or a combination of alkaline solutions such as a calcium hydroxide solution, a potassium hydroxide solution, a sodium carbonate solution, and a potassium carbonate solution.

[0030] The waste heat or the electricity that has not been fed into the grid in the waste incineration power plant heats the hydrothermal degradation device 1, keeping the temperature of the fly ash slurry in the hydrothermal degradation device 1 at 200 °C, and being in a subcritical or critical state under high temperature and high pressure conditions, with extremely strong oxidizing properties. After the fly ash is mixed with the condensed water conveyed by the first condensed water pipeline 8, a fly ash slurry with a water-to-ash ratio of 2:1 is formed. After entering the hydrothermal degradation device 1, it stays at 200 °C for 2 h. The heavy metals in the fly ash slurry are solidified under alkaline conditions, and organic substances such as dioxins in the fly ash slurry are rapidly degraded under strong oxidizing conditions.

[0031] As Figure 2 shown, the water washing device 2 in this embodiment is a three-stage water washing device 2, including a first-stage water washing device 5, a second-stage water washing device 6, and a third-stage water washing device 7. The first-stage water washing device 5 is connected to the second reagent adding device, and each stage of the water washing device 2 is provided with an inlet, a washing liquid inlet, a washing liquid outlet, and a wet ash outlet. A solid-liquid separation unit is also configured in each stage of the water washing device 2. The solid-liquid separation unit is a plate and frame filter press, and the washing liquid and the wet ash are separated by means of plate and frame filtration. In this embodiment, the second reagent is a sodium carbonate solution. Of course, in other embodiments, the second reagent can also be one or a combination of sodium phosphate and sodium sulfate solutions.

[0032] The inlet of the first-stage water washing device 5 is connected to the outlet of the hydrothermal degradation device 1, the wet ash outlet of the first-stage water washing device 5 is connected to the inlet of the second-stage water washing device 6, and the washing liquid outlet of the first-stage water washing device 5 is connected to the inlet of the regulating device 3; the wet ash outlet of the second-stage water washing device 6 is connected to the inlet of the third-stage water washing device 7, and the washing liquid outlet of the second-stage water washing device 6 is connected to the washing liquid inlet of the first-stage 5 washing liquid; the washing liquid outlet of the third-stage water washing device 7 is connected to the washing liquid inlet of the second-stage 6 washing liquid, the washing liquid inlet of the third-stage water washing device 7 is connected to the second condensed water pipeline 9, and the wet ash outlet of the third-stage water washing device 7 is connected to the device for resource utilization of wet ash, and this device is used to make bricks, pottery, and cement admixtures from the wet ash discharged from the wet ash outlet.

[0033] The fly ash slurry after hydrothermal degradation enters the water washing device 2 from the outlet of the hydrothermal degradation device 1 for three-stage water washing. The fly ash slurry enters the first-stage water washing device 5 from the inlet of the first-stage water washing device 5 for the first water washing. During the water washing process, the water-to-ash ratio is adjusted to 3:1, the chloride ions in the fly ash slurry are dissolved out, and calcium and magnesium ions in the fly ash slurry form precipitates under the action of the second medicament. The fly ash slurry after precipitation is subjected to solid-liquid separation by the solid-liquid separation unit, separated into washing liquid and wet ash. The wet ash separated by the first-stage water washing device 5 enters the second-stage water washing device 6 from the inlet of the second-stage water washing device 6. After the second water washing and solid-liquid separation, the chloride ions in the wet ash are further dissolved into the washing liquid, and calcium and magnesium ions precipitate in the wet ash, separated into washing liquid and wet ash. The washing liquid separated by the second-stage water washing device 6 is transported back to the first-stage water washing device 5, and the separated wet ash enters the third-stage water washing device 7 for the third water washing and solid-liquid separation, dissolving the chloride ions in the wet ash into the washing liquid, and calcium and magnesium ions precipitate in the wet ash, separating the washing liquid and wet ash again. The washing liquid separated by the third-stage water washing device 7 is transported back to the second-stage water washing device 6, and the separated wet ash is discharged out of the system for resource treatment and used to manufacture building materials resources. Due to three-stage water washing, chloride ions are dissolved out multiple times and completely enter the washing liquid, reducing the chlorine content in the wet ash separated by the third-stage water washing device 7 and avoiding the corrosion and poor durability of the building materials resources made from the wet ash due to high chlorine content.

[0034] The adjusting device 3 adopts an adjusting tank, connected with a third medicament adding device. The third medicament is hydrochloric acid, used to adjust the pH value of the washing liquid, and the outlet of the adjusting device 3 is connected with the evaporation crystallization device 4. The washing liquid separated by the first-stage water washing device 5 enters the adjusting device 3 from the inlet of the adjusting device 3, the pH is adjusted to 7, and after further precipitation and filtration, it enters the evaporation crystallization device 4.

[0035] The evaporation crystallization device 4 adopts a multi-effect evaporator, connected with the waste heat boiler or waste heat power generation system in the waste incineration power plant, and a first condensate pipeline 8 connected with the hydrothermal degradation device 1 and a second condensate pipeline 9 connected with the third-stage water washing device 7 are arranged on the evaporation crystallization device 4. The surplus steam in the waste incineration power plant is used as the heating medium to indirectly heat the evaporation crystallization device 4.

[0036] The evaporation crystallization device 4 utilizes the difference in the solubility of sodium chloride and potassium chloride with the change of temperature. First, the washing liquid is evaporated and crystallized to obtain sodium chloride crystal salt. After separating the sodium chloride crystal salt, the mother liquor is cooled to obtain potassium chloride crystal salt. The condensate water during the evaporation process returns to the hydrothermal degradation device 1 and the water washing device 2 through the first condensate pipeline 8 and the second condensate pipeline 9, realizing the recycling of water resources in the system and saving water resources.

[0037] The utility model can utilize the surplus heat energy and the unconnected-to-grid electric energy in a waste incineration power plant as the heat supply source, completely treat the harmful substances in fly ash, utilize the useful substances in fly ash, degrade dioxins, solidify heavy metals, resourcefully utilize building materials resources and evaporate and crystallize metal salts that can be sold, avoid the waste of energy and resources in the waste incineration power plant, reduce the fly ash treatment cost, and improve the operating efficiency.

[0038] Embodiment 2 of the on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant provided by the utility model:

[0039] As Figure 1 shown, the on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant includes a hydrothermal degradation device 1, a water washing device 2, an adjusting device 3 and an evaporation and crystallization device 4.

[0040] The hydrothermal degradation device 1 is connected with a first medicament adding device and is connected with a waste heat boiler or a waste heat power generation system in the waste incineration power plant. The first medicament adding device is used for adding a first medicament into the hydrothermal degradation device 1, and the first medicament is a sodium hydroxide solution, hydrogen peroxide and a ferric chloride solution. Of course, in other embodiments, the sodium hydroxide solution in the first medicament can be replaced by one or a combination of alkaline solutions such as a calcium hydroxide solution, a potassium hydroxide solution, a sodium carbonate solution, a potassium carbonate solution, etc.

[0041] The waste heat or the unconnected-to-grid electric energy in the waste incineration power plant heats the hydrothermal degradation device 1, so that the temperature of the fly ash slurry in the hydrothermal degradation device 1 is maintained at 250 °C and is in a subcritical or critical state under high temperature and high pressure conditions, with extremely strong oxidizing properties. After the fly ash is mixed with the condensed water conveyed by the first condensed water pipeline 8, a fly ash slurry with a water-to-ash ratio of 3:1 is formed and enters the hydrothermal degradation device 1 and stays for 1 h at 250 °C. The heavy metals in the fly ash slurry are solidified under alkaline conditions, and the organic substances such as dioxins in the fly ash slurry are rapidly degraded under strong oxidizing conditions.

[0042] As Figure 2 shown, the water washing device 2 in this embodiment is a three-stage water washing device 2, including a first-stage water washing device 5, a second-stage water washing device 6 and a third-stage water washing device 7. The first-stage water washing device 5 is connected with a second medicament adding device, and each stage of the water washing device 2 is provided with an inlet, a water washing liquid inlet, a water washing liquid outlet and a wet ash outlet. A solid-liquid separation unit is also configured in each stage of the water washing device 2, and the solid-liquid separation unit is a horizontal spiral centrifuge, and the water washing liquid and the wet ash are separated by the horizontal spiral centrifugation method. In this embodiment, the second medicament is a sodium carbonate solution. Of course, in other embodiments, the second medicament can also be one or a combination of sodium phosphate and sodium sulfate solutions.

[0043] The inlet of the first-stage water washing device 5 is connected to the outlet of the hydrothermal degradation device 1. The wet ash outlet of the first-stage water washing device 5 is connected to the inlet of the second-stage water washing device 6. The water washing liquid outlet of the first-stage water washing device 5 is connected to the inlet of the regulating device 3. The wet ash outlet of the second-stage water washing device 6 is connected to the inlet of the third-stage water washing device 7. The water washing liquid outlet of the second-stage water washing device 6 is connected to the water washing liquid inlet of the first-stage 5 water washing liquid. The water washing liquid outlet of the third-stage water washing device 7 is connected to the water washing liquid inlet of the second-stage 6 water washing liquid. The water washing liquid inlet of the third-stage water washing device 7 is connected to the second condensed water pipeline 9. The wet ash outlet of the third-stage water washing device 7 is connected to a device for resource utilization of wet ash, and this device is used to make bricks, pottery, and cement admixtures from the wet ash discharged from the wet ash outlet.

[0044] The fly ash slurry after hydrothermal degradation enters the water washing device 2 from the outlet of the hydrothermal degradation device 1 for three-stage water washing. The fly ash slurry enters the first-stage water washing device 5 from the inlet of the first-stage water washing device 5 for the first water washing. During the water washing process, the water-to-ash ratio is adjusted to 4:1, and the chloride ions in the fly ash slurry are dissolved out. Calcium and magnesium ions in the fly ash slurry form precipitates under the action of the second reagent. The precipitated fly ash slurry is subjected to solid-liquid separation by the solid-liquid separation unit, separated into water washing liquid and wet ash. The wet ash separated by the first-stage water washing device 5 enters the second-stage water washing device 6 from the inlet of the second-stage water washing device 6. After the second water washing and solid-liquid separation, the chloride ions in the wet ash are further dissolved into the water washing liquid, and calcium and magnesium ions precipitate in the wet ash, separated into water washing liquid and wet ash. The water washing liquid separated by the second-stage water washing device 6 is transported back to the first-stage water washing device 5. The separated wet ash enters the third-stage water washing device 7 for the third water washing and solid-liquid separation, dissolving the chloride ions in the wet ash into the water washing liquid, and calcium and magnesium ions precipitate in the wet ash, separating the water washing liquid and wet ash again. The water washing liquid separated by the third-stage water washing device 7 is transported back to the second-stage water washing device 6. The separated wet ash is discharged out of the system for resource treatment and used to manufacture building materials resources. Due to three-stage water washing, chloride ions are dissolved out multiple times and completely enter the water washing liquid, reducing the chlorine content in the wet ash separated by the third-stage water washing device 7 and avoiding the corrosion and short durability of the building materials resources made from wet ash due to high chlorine content.

[0045] The regulating device 3 adopts a regulating tank, connected with a third reagent adding device. The third reagent is hydrochloric acid, used to adjust the pH value of the water washing liquid. And the outlet of the regulating device 3 is connected to the evaporation crystallization device 4. The water washing liquid separated by the first-stage water washing device 5 enters the regulating device 3 from the inlet of the regulating device 3, the pH is adjusted to 7.5, and after further precipitation and filtration, it enters the evaporation crystallization device 4.

[0046] The evaporation crystallization device 4 adopts an MVR evaporator, which is connected to the waste heat boiler or waste heat power generation system in the waste incineration power plant. A first condensate pipeline 8 connected to the hydrothermal degradation device 1 and a second condensate pipeline 9 connected to the third-stage water washing device 7 are provided on the evaporation crystallization device 4. The surplus steam in the waste incineration power plant is used as the heating medium to indirectly heat the evaporation crystallization device 4.

[0047] The evaporation crystallization device 4 utilizes the difference in the solubility of sodium chloride and potassium chloride with the change of temperature. First, the washing liquid is evaporated and crystallized to obtain sodium chloride crystal salt. After separating the sodium chloride crystal salt, the mother liquor is cooled to obtain potassium chloride crystal salt. The condensate water during the evaporation process returns to the hydrothermal degradation device 1 and the water washing device 2 through the first condensate pipeline 8 and the second condensate pipeline 9, realizing the recycling of water resources in the system and saving water resources.

[0048] Certainly, in other embodiments, the temperature of the solvent in the hydrothermal degradation device 1 can be maintained at 200 - 250 °C. After the fly ash enters the hydrothermal degradation device 1, it can stay for 0.5 - 24 h to form a fly ash slurry with a water-to-ash ratio of 1:1 - 5:1. The water washing device 2 can be set to more than three stages, and the water-to-ash ratio can be adjusted to 3:1 during the water washing process. Hydrochloric acid can be added in the adjusting device 3 to adjust the pH of the washing liquid to 7 - 8.

[0049] In addition, in the description of this specification, the meaning of "a plurality of" is at least two, such as two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. An on-line hydrothermal degradation and resource utilization disposal system for fly ash in a waste incineration power plant, characterized in that, It includes a hydrothermal degradation device, a water washing device, an adjusting device, and an evaporation crystallization device; The outlet of the hydrothermal degradation device is connected to the inlet of the water washing device. The hydrothermal degradation device is used to be connected to the waste heat boiler or waste heat power generation system in a waste incineration power plant to degrade dioxins in fly ash and solidify heavy metals in fly ash; The water washing device is used to extract soluble salts in fly ash, further solidify calcium ions and heavy metals in fly ash, and separate out washing liquid and wet ash. The water washing device is provided with a washing liquid outlet and a wet ash outlet; the washing liquid outlet is connected to the adjusting device; The adjusting device is used to adjust the pH value of the washing liquid and further precipitate and filter suspended solids in the washing liquid. The outlet of the adjusting device is connected to the evaporation crystallization device; The evaporation crystallization device is connected to the waste heat boiler or the waste heat power generation system and is used to evaporate and crystallize the washing liquid with the adjusted pH value and separate out sodium chloride and potassium chloride.

2. An on-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to claim 1, characterized in that, The water washing device includes a solid-liquid separation unit, and the solid-liquid separation unit adopts one of a pressure filtration separation device, a vertical centrifugal separation device, and a horizontal screw centrifugal separation device.

3. An on-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to claim 2, characterized in that, The water washing device has multiple stages. Each stage of the water washing device is also provided with a washing liquid inlet. The washing liquid outlet of the lower-stage water washing device is connected to the washing liquid inlet of the upper-stage water washing device. The wet ash outlet of the upper-stage water washing device is connected to the inlet of the lower-stage water washing device. The washing liquid outlet of the first-stage water washing device is connected to the adjusting device. The wet ash outlet of the last-stage water washing device is used to connect to a device for resource utilization of wet ash.

4. An on-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to claim 3, characterized in that, The evaporation crystallization device is provided with a condensed water outlet. A first condensed water pipeline for introducing condensed water into the hydrothermal degradation device is connected between the condensed water outlet and the hydrothermal degradation device.

5. An on-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to claim 4, characterized in that, A second condensed water pipeline for introducing condensed water into the last-stage water washing device is connected between the condensed water outlet and the last-stage water washing device.

6. An on-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to any one of claims 1-5, characterized in that, The hydrothermal degradation device is connected to a first chemical agent adding device. The first chemical agent adding device is used to add an alkaline solution, hydrogen peroxide, and an iron ion solution into the hydrothermal degradation device. The alkaline solution is one or a combination of sodium hydroxide, calcium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate solutions.

7. An in-line fly ash hydrothermal degradation and resource utilization disposal system for a waste incineration power plant according to any one of claims 1-5, characterized in that, The water washing device is connected to a second chemical agent adding device. The second chemical agent adding device is used to add one or a combination of sodium carbonate, sodium phosphate, and sodium sulfate solutions into the water washing device.

8. An on-line hydrothermal degradation and resource utilization system for fly ash in a waste incineration power plant according to any one of claims 1-5, characterized in that, The evaporation crystallization device is one of a multi-effect evaporator and an MVR evaporator.

Images