Treatment system for recycling waste incineration fly ash

Abstract

The utility model discloses a treatment system for recycling waste incineration fly ash. The treatment system comprises a raw ash bin, a washing system, a washed fly ash temporary storage bin, a paddle dryer, a low-temperature thermal decomposition furnace and a solid sample storage bin. The raw ash bin, the washing system, the washing fly ash temporary storage bin, the paddle dryer, the low-temperature thermal decomposition furnace and the solid sample storage bin are sequentially communicated with one another; the input end of the paddle dryer is communicated with an external hot steam supply unit; the treatment system further comprises a flue gas treatment system, and the gas outlet end of the paddle dryer and the gas outlet end of the low-temperature thermal decomposition furnace are both communicated with the flue gas treatment system through suction assemblies. According to the invention, a process of firstly washing and then cracking is adopted, and a drying technology is added before the cracking process, so that the energy consumption is saved, the cracking temperature can be reduced to 300-400 DEG C, and toxic and harmful substances such as dioxin can be effectively removed, thereby solving the problem of unstable curing after a long time.

Description

Technical Field

[0001] The present application relates to the technical field of solid waste treatment, and in particular to a treatment system for recycling fly ash from waste incineration. Background Art

[0002] At present, the disposal of fly ash from garbage incineration in my country is still mainly landfilled after solidification. Although the technology of fly ash solidification landfill is mature and the cost is low, there are still many disadvantages. First, the land in developed areas is very expensive, and it is difficult to select a landfill site. In addition, the capacity of garbage landfill sites across the country is close to saturation, and the landfill process needs to permanently occupy a large amount of land resources. Secondly, fly ash solidification landfill will cause a high risk to the environment. Salt and heavy metals are easily leached, and dioxins are not eliminated. The solidification is unstable after a long time. At the same time, fly ash solidification landfill also has problems such as the garbage treatment facilities are far away from the urban area and the transportation and treatment costs are high.

[0003] The patented technologies in the waste incineration fly ash resource utilization are mostly to first crack and then wash, or to crack at 300-800℃ in an anaerobic atmosphere after washing or acid washing. However, such treatment methods not only require high energy consumption, but also fail to eliminate toxic and harmful substances such as dioxins, and the solidification will become unstable after a long time. Utility Model Content

[0004] The purpose of the present application is to provide a treatment system for waste incineration fly ash resource utilization, so as to solve the problem that most of the patented technologies in the related art are first cracking and then washing, or after washing or acid washing, cracking at 300-800℃ in an anaerobic atmosphere. However, such treatment methods not only require large energy consumption, but also fail to eliminate toxic and harmful substances such as dioxins, and the problem of unstable solidification will occur after a long time.

[0005] The present application provides a waste incineration fly ash resource processing system using the following technical solutions:

[0006] A processing system for recycling fly ash from garbage incineration, comprising a raw ash bin, a water washing system, a water-washed fly ash buffer bin, a paddle dryer, a low-temperature thermal decomposition furnace, and a solid sample storage bin;

[0007] The raw ash bin, the water washing system, the water-washed fly ash buffer bin, the paddle dryer, the low-temperature thermal decomposition furnace and the solid sample storage bin are adjacent to each other in sequence;

[0008] The input end of the paddle dryer is in communication with an external hot steam supply unit;

[0009] The treatment system also includes a flue gas treatment system, and the gas outlet end of the paddle dryer and the gas outlet end of the low-temperature thermal decomposition furnace are respectively connected to the flue gas treatment system through a suction component.

[0010] Further, the flue gas treatment system includes a bag filter, a spray tower, an activated carbon adsorber, and an incinerator, and the bag filter, the spray tower, the activated carbon adsorber, and the incinerator are sequentially and mutually communicated adjacent to each other;

[0011] The air outlet ends of the paddle dryer and the low-temperature pyrolysis furnace are respectively connected to the input end of the bag filter through the suction assembly.

[0012] Further, the treatment system further includes a wastewater treatment system, and the wastewater treatment system is communicated with the water washing system to perform salt separation and purification treatment on the washing liquid generated during the water washing process.

[0013] Further, the input port of the water washing system is communicated with an external heavy metal medicament bin.

[0014] Further, the input port of the low-temperature pyrolysis furnace is communicated with an external dioxin detoxification chelating agent storage bin.

[0015] Further, a condensate water pipe is provided at the output end of the paddle dryer, and a condensate water valve is provided on the condensate water pipe.

[0016] Further, the suction assembly includes an induced draft fan, an absorption pipe and a discharge pipe are respectively connected to the absorption end and the discharge end of the induced draft fan, one end of the absorption pipe is connected with a tee pipe, and both ends of the tee pipe are respectively connected to the air outlet ends of the paddle dryer and the low-temperature pyrolysis furnace, and one end of the discharge pipe is connected to the input end of the bag filter.

[0017] Further, the bag filter is connected to the water washing fly ash buffer bin through a circulating dust conveying structure.

[0018] Compared with the prior art, the beneficial effects of the present application are as follows: By setting up a system in which the raw ash bin, the water washing system, the water washing fly ash buffer bin, the paddle dryer, the low-temperature pyrolysis furnace, and the solid sample storage bin cooperate with each other, the system adopts a process of first water washing and then cracking, and adds a drying technology before the cracking process. It not only saves energy consumption and can reduce the cracking temperature to 300-400 °C, but also can effectively remove toxic and harmful substances such as dioxin, thus being able to solve the problem of unstable solidification after a long time.

[0019] At the same time, through the setting of the flue gas purification system, the waste gas can be effectively purified, thus effectively reducing environmental pollution. Moreover, the finally obtained solid sample product is used for fly ash building material utilization, which can not only generate income but also avoid fly ash solidification and landfill, thus solving the industry problem of land waste and forming a circular utilization of resources. Brief Description of the Drawings

[0020] Figure 1 It is a flowchart of the treatment system for resource utilization of waste incineration fly ash in the embodiments of the present application.

[0021] Figure 2 It is a flowchart of the fly ash washing process in the embodiments of the present application. Specific Embodiments

[0022] The following further elaborates on the present application in conjunction with the attached Figure 1-2 drawings.

[0023] The embodiments of the present application disclose a treatment system for resource utilization of waste incineration fly ash. Referring to Figure 1 , in this embodiment, the treatment system includes a raw ash bin, a washing system, a washed fly ash buffer bin, a paddle dryer, a low-temperature pyrolysis furnace, and a solid sample storage bin. Among them, the raw ash bin is used to temporarily store waste incineration fly ash; the washing system cooperates with and is connected to the raw ash bin, and the washed fly ash buffer bin cooperates with and is connected to the washing system.

[0024] Specifically, referring to Figure 2 , in this embodiment, the washing system mainly consists of the following equipment: a washing tank, a plate and frame filter press, a conical bin, a low-temperature catalytic cracking system, a slurry transfer pump, a washed ash conveyor belt, and a filtrate storage tank. Among them, the washing tank is divided into washing tank A and washing tank B, and the plate and frame filter press is divided into plate and frame filter press 1, plate and frame filter press 2, plate and frame filter press 3, and plate and frame filter press 4.

[0025] More specifically, the washing system is divided into two-stage processes; among them, the first-stage process consists of washing tank A, plate and frame filter press 1, plate and frame filter press 2, the washed ash conveyor belt, and the slurry transfer pump; washing tank A is connected to and cooperates with the raw ash bin; plate and frame filter press 1 and plate and frame filter press 2 are respectively connected to washing tank A; the waste incineration fly ash in the raw ash bin is transported to washing tank A for thorough stirring and washing, and the washed fly ash slurry is transported into plate and frame filter press 1 or plate and frame filter press 2 for pressure filtration and dehydration. Preferably, plate and frame filter press 1 and plate and frame filter press 2 work in a staggered manner.

[0026] Moreover, the above-mentioned plate and frame filter press has the characteristics of large driving force, high solid content rate of the filter cake, clear filtrate, and high solid recovery rate. According to empirical data, the fly ash slurry can be pressure-filtered to a moisture content of less than 35% to obtain the eluted filter cake.

[0027] Preferably, in this embodiment, the processing system further includes a wastewater treatment system, which is simultaneously connected to the output ends of the plate-and-frame filter press 1 and the plate-and-frame filter press 2, so that the first filtrate obtained by dehydration in the plate-and-frame filter press 1 and the plate-and-frame filter press 2 is transported to the wastewater treatment system, which can effectively perform salt separation and purification treatment on the first filtrate, and the industrial salt by-products generated can be used for income generation. In addition, the wastewater treatment system also recycles the treated washing liquid and transports the washing liquid back to the washing system as makeup water for the washing process.

[0028] And the filter cake after pressure filtration is subjected to a second washing in the plate-and-frame filter press 1 or the plate-and-frame filter press 2, and the secondary filtrate after the secondary washing is re-transported back to the washing tank A for recycling, so that the filtrate can be subjected to cyclic elution treatment.

[0029] Meanwhile, the second-stage section consists of a washing tank B, a plate-and-frame filter press 3, a plate-and-frame filter press 4, a washing ash conveying belt, and a slurry conveying pump; the washing tank B is simultaneously connected to the plate-and-frame filter press 1 and the plate-and-frame filter press 2, and the washing ash conveying belt and the slurry conveying pump are installed between the washing tank B and the plate-and-frame filter press 1 and the plate-and-frame filter press 2 respectively. When the filter cake is dehydrated to about 35% moisture content, it is transported into the washing tank B under the action of the washing ash conveying belt and the slurry conveying pump for the second-stage washing. Specifically, the washing tank B adopts the same design parameters as the washing tank A.

[0030] Preferably, the washing tank B is connected to an external clear water tank, and a clear water conveying pump is installed between the washing tank B and the clear water tank. Under the action of the clear water conveying pump, the clear water in the clear water tank is transported into the washing tank B to supplement water for the filter cake in the washing tank B, so as to facilitate the second-stage elution process of the filter cake.

[0031] When the filter cake generated by the first-stage washing enters the washing tank B for the second-stage washing, the fly ash is washed three times in the washing tank B, and the slurry after the three-time washing enters the plate-and-frame filter press 3 or the plate-and-frame filter press 4 for secondary pressure filtration, and the plate-and-frame filter press 3 and the plate-and-frame filter press 4 work in a staggered manner; and the plate-and-frame filter press 3 and the plate-and-frame filter press 4 are also simultaneously connected to a storage tank, and the storage tank is also connected to the washing tank A through a circulating pump structure.

[0032] The filter cake after pressure filtration is subjected to a fourth washing in the plate-and-frame filter press 3 or the plate-and-frame filter press 4, the primary filtrate after pressure filtration enters the storage tank for storage, and then under the action of the circulating pump structure, the filtrate in the storage tank is cyclically supplied to the washing tank A for the first-stage use. And the secondary filtrate generated by pressure filtration in the plate-and-frame filter press 3 or the plate-and-frame filter press 4 is re-transported into the washing tank B for recycling.

[0033] The plate-and-frame filter press 3 and the plate-and-frame filter press 4 are simultaneously interconnected with the conical silo. The washed ash conveyor belt and the slurry pump are installed between the plate-and-frame filter press 3, the plate-and-frame filter press 4, and the conical silo. Moreover, the conical silo is interconnected with the low-temperature catalytic cracking system, and the low-temperature catalytic cracking system is interconnected with the washed fly ash buffer bin.

[0034] Under the action of the washed ash conveyor belt and the slurry pump, the filter cakes with a water content of about 35% after the discharge of the plate-and-frame filter press 3 and the plate-and-frame filter press 4 are conveyed into the conical silo for temporary storage, and then these filter cakes are conveyed into the low-temperature catalytic cracking system for further treatment in the low-temperature degradation section. Finally, the fly ash filter cakes after the low-temperature degradation treatment are conveyed into the washed fly ash buffer bin.

[0035] Therefore, after the fly ash is eluted as above, the soluble chlorides therein can be effectively removed, and the chlorine content in the fly ash can be reduced, so that the resynthesis of dioxins in the subsequent process can be effectively avoided in this link. More specifically, the chloride ion removal rate in the fly ash can reach more than 90%, and the alkali metal removal rate can reach more than 80%, meeting the requirements of the Technical Specification for Pollution Control of Municipal Solid Waste Incineration Fly Ash (HJ1134-2020).

[0036] Preferably, referring to Figure 1 , in this embodiment, the input port of the washing system is interconnected with the external heavy metal reagent bin. The heavy metal reagent bin is used to store heavy metal stabilizers. By adding a set proportion of heavy metal stabilizers into the three-stage washing system, the heavy metals contained in the municipal solid waste incineration fly ash can be treated, so that the leaching risk of heavy metals in the fly ash building material products can be reduced.

[0037] In addition, referring to Figure 1 , in this embodiment, the paddle dryer is cooperated with and interconnected with the washed fly ash buffer bin. The washed fly ash is conveyed from the washed fly ash buffer bin into the paddle dryer, and the input end of the paddle dryer is interconnected with the external hot steam supply unit. The external hot steam supply unit discharges steam into the paddle dryer.

[0038] By feeding the washed fly ash into the paddle dryer and drying the fly ash by indirect steam heating, the hot steam effectively dries the washed fly ash through the rotation and stirring of the paddle blades, so that the water content of the dried material reaches less than 5%. In addition, by drying in the paddle dryer first, the energy consumption in the subsequent thermal decomposition section can be saved.

[0039] Preferably, in this embodiment, a condensate water pipe is further installed at the bottom output end of the paddle dryer, and a condensate water valve is installed on the condensate water pipe. Through the cooperation of the condensate water pipe and the condensate water valve, the condensate water generated in the paddle dryer can be effectively drained away.

[0040] In addition, refer to Figure 1 In this embodiment, the low-temperature thermal decomposition furnace and the paddle dryer are connected to each other through a spiral conveying structure. Under the action of the spiral conveying structure, the material dried in the paddle dryer can be transported to the low-temperature thermal decomposition furnace.

[0041] Specifically, the input port of the low-temperature thermal decomposition furnace is interconnected with an external dioxin detoxification chelating agent storage bin, and the dioxin detoxification chelating agent storage bin is used to store the dioxin detoxification chelating agent; by adding a set proportion of dioxin detoxification chelating agent into the low-temperature thermal decomposition furnace, the dioxin detoxification chelating agent and the dioxins in the fly ash undergo a dechlorination and detoxification reaction, effectively reducing the toxicity of the dioxins, and at the same time, chelating different heavy metal ions in the fly ash to stabilize the heavy metal ions in the fly ash, providing good support for fly ash resource utilization, thereby achieving good removal effect on heavy metals, convenient operation, safety and environmental protection, and then the treated material is thermally decomposed at a temperature of 335-380°C and a time of 25-60min, thereby being able to effectively degrade and remove the dioxin content in the fly ash, and then obtaining a solid sample product.

[0042] Secondly, the solid sample storage bin and the low-temperature thermal decomposition furnace cooperate with each other and are interconnected, so that the solid sample products obtained after thermal decomposition can be discharged into the solid sample storage bin for cooling and temporary collection, so that the fly ash by-products of the solid sample products can be subsequently utilized as building materials. This not only increases income, but also avoids the solidification and landfill of fly ash, solves the industry problem of land waste, and thus forms a recycling of resources.

[0043] Better, refer to Figure 1 In this embodiment, the treatment system also includes a flue gas treatment system, which is interconnected with the air outlet end of the paddle dryer and the air outlet end of the low-temperature thermal decomposition furnace through a suction component, so as to achieve effective purification of the waste gas generated by the paddle dryer and the low-temperature thermal decomposition furnace, thereby effectively reducing environmental pollution.

[0044] Specifically, the flue gas treatment system includes a bag filter, a spray tower, an activated carbon adsorber and an incinerator. The bag filter, the spray tower, the activated carbon adsorber and the incinerator are connected to each other in sequence through a conveying pipeline. At the same time, the input end of the bag filter is connected to the air outlet end of the paddle dryer and the air outlet end of the low-temperature thermal decomposition furnace through a suction component, so that the exhaust gas passes through the bag filter, the spray tower, the activated carbon adsorber and the incinerator in sequence under the suction action of the suction component.

[0045] More specifically, the suction assembly includes an induced draft fan, an absorption pipe, a discharge pipe, and a tee. Among them, the induced draft fan is installed on one side of the bag filter; the absorption pipe and the discharge pipe are fixedly connected to the absorption end and the discharge end of the induced draft fan respectively; one end of the tee is fixedly connected to the end of the absorption pipe away from the induced draft fan, and the other two ends of the tee are respectively connected to the air outlet end of the paddle dryer and the air outlet end of the low-temperature pyrolysis furnace, and the end of the discharge pipe away from the induced draft fan is connected to the input end of the bag filter.

[0046] When the induced draft fan is started, the tee sucks the waste gases generated by the paddle dryer and the low-temperature pyrolysis furnace into the absorption pipe respectively, and then transports them along the discharge pipe to the bag filter. The bag filter is used to filter and remove the particulate matter in the waste gas, and then transports it along the conveying pipeline to the spray tower. The spray tower is used to remove the residual powder in the waste gas, and then transports it along the conveying pipeline to the activated carbon adsorber. The activated carbon adsorber is used to remove the dioxin pollutants in the waste gas to obtain the purified waste gas. Finally, the purified waste gas enters the incinerator for co-treatment through the conveying pipeline, so as to effectively reduce environmental pollution.

[0047] Preferably, in this embodiment, the bag filter and the washed fly ash buffer bin are also connected to each other through a circulating dust conveying structure. By setting the circulating dust conveying structure, the secondary fly ash filtered in the bag filter can be effectively circulated and conveyed, so as to convey the secondary fly ash into the washed fly ash buffer bin for circulating treatment, thereby further realizing the recycling of resources.

[0048] The implementation principle of the treatment system for waste incineration fly ash resource utilization in the embodiment of the present application is as follows:

[0049] First, the waste incineration fly ash is transported from the original ash bin to the washing system, and after three-stage washing, it enters the washed fly ash buffer bin for storage; at the same time, a heavy metal stabilizer is added to the washing system in a set proportion, and the washing liquid generated during the three-stage washing process is subjected to salt separation and purification treatment. Then, the fly ash after the washing process is transported to the paddle dryer, and the fly ash is dried by indirect steam heating. The hot steam effectively dries the washed fly ash through the rotation and stirring of the paddle; at the same time, the cooperation of the condensate pipe and the condensate valve is used to facilitate the discharge of the condensate generated in the paddle dryer.

[0050] Then, the dried material is conveyed into the low-temperature pyrolysis furnace through the spiral conveying structure and pyrolyzed at 335-380 °C for 25-60 minutes. At the same time, a dioxin detoxification chelating agent with a set ratio is added into the low-temperature pyrolysis furnace. Finally, the solid sample product obtained after pyrolysis is discharged into the solid sample storage bin for cooling and collection and temporary storage, so as to facilitate the subsequent utilization of the fly ash by-product of the solid sample product as building materials, which can not only generate income but also avoid the solidification and landfill of fly ash, solve the industry problem of land waste, and then form a circular utilization of resources.

[0051] In addition, the waste gases generated by the paddle dryer and the low-temperature pyrolysis furnace respectively are, under the action of the suction assembly, purified in sequence through "bag filter + spray tower + activated carbon adsorption" and then enter the incinerator for co-treatment, so as to effectively reduce environmental pollution. At the same time, the secondary fly ash filtered in the bag filter is circulated and conveyed through the circulating dust conveying structure to the washing fly ash buffer bin for circulating treatment.

[0052] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural or equivalent process transformations made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are similarly included in the patent protection scope of the present invention.

Claims

1. A waste incineration fly ash resource processing system, characterized by: It includes raw ash bin, water washing system, water-washed fly ash buffer bin, paddle dryer, low-temperature thermal decomposition furnace and solid sample storage bin; The raw ash bin, the water washing system, the water-washed fly ash buffer bin, the paddle dryer, the low-temperature thermal decomposition furnace and the solid sample storage bin are adjacent to each other in sequence; The input end of the paddle dryer is in communication with an external hot steam supply unit; The treatment system also includes a flue gas treatment system, and the gas outlet end of the paddle dryer and the gas outlet end of the low-temperature thermal decomposition furnace are respectively connected to the flue gas treatment system through a suction component.

2. A waste incineration fly ash resource processing system according to claim 1, characterized in that: The flue gas treatment system comprises a bag filter, a spray tower, an activated carbon adsorber and an incinerator, wherein the bag filter, the spray tower, the activated carbon adsorber and the incinerator are adjacent to each other in sequence; The air outlet end of the paddle dryer and the air outlet end of the low-temperature thermal decomposition furnace are respectively connected to the input end of the bag filter through the suction assembly.

3. A waste incineration fly ash resource processing system according to claim 1, characterized in that: The treatment system also includes a wastewater treatment system, which is connected to the water washing system to perform salt separation and purification treatment on the washing liquid generated during the water washing process.

4. A waste incineration fly ash resource processing system according to claim 1, characterized in that: The input port of the water washing system is connected to an external heavy metal agent bin.

5. A waste incineration fly ash resource processing system according to claim 1, characterized in that: The input port of the low-temperature thermal decomposition furnace is communicated with an external dioxin detoxification chelating agent storage bin.

6. A waste incineration fly ash resource processing system according to claim 1, characterized in that: The output end of the paddle dryer is provided with a condensation water pipe, and the condensation water pipe is provided with a condensation water valve.

7. A waste incineration fly ash resource processing system according to claim 2, characterized in that: The suction assembly includes an induced draft fan, the suction end and discharge end of the induced draft fan are respectively connected to an absorption pipe and a discharge pipe, one end of the absorption pipe is connected to a three-way pipe, the two ends of the three-way pipe are respectively interconnected with the air outlet end of the paddle dryer and the air outlet end of the low-temperature thermal decomposition furnace, and one end of the discharge pipe is connected to the input end of the bag filter.

8. A waste incineration fly ash resource processing system according to claim 7, characterized in that: The bag filter and the water-washed fly ash buffer bin are connected via a circulating dust conveying structure.

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