Waste incineration power plant coupled waste incineration fly ash treatment system
By coupling a waste-to-energy plant with a waste-to-incineration fly ash treatment system, calcium carbonate precipitate is formed through the chemical reaction of leachate and washing filtrate, reducing reagent costs. Filter cake and evaporation condensate are recycled as desulfurizing agents, solving the problem of high reagent costs in waste-to-incineration fly ash disposal and achieving resource utilization and improved economic benefits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG JINGLAN ENVIRONMENTAL PROTECTION TECH CO LTD
- Filing Date
- 2025-07-24
- Publication Date
- 2026-06-26
AI Technical Summary
In the existing process of treating fly ash from waste incineration, the water washing process requires the addition of additional chemicals, resulting in high costs. Furthermore, the high alkalinity of leachate from waste incineration power plants makes it difficult to achieve effective coupling optimization.
The waste incineration fly ash treatment system is coupled with the waste incineration power plant. The fly ash is detoxified through a pyrolysis furnace. The mixture of leachate and washing filtrate forms calcium carbonate precipitate, reducing reagent costs. The filter cake from the rigid plate and frame filter cake is mixed with the evaporation condensate and recycled as a desulfurizing agent. Heat is recycled in combination with steam from the steam turbine.
Significantly reduce the cost of chemical use, realize resource utilization, save the operating costs of waste incineration power plants, and achieve an economically feasible low-carbon and environmentally friendly solution.
Smart Images
Figure CN224406042U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of waste incineration fly ash disposal technology, specifically relating to a waste incineration fly ash treatment system coupled with a waste incineration power plant. Background Technology
[0002] Current waste incineration fly ash disposal processes involve water washing, but the wash filtrate has high hardness, generally requiring the addition of chemicals for hardening, which increases both chemical and energy costs. Meanwhile, the leachate from waste-to-energy power plants has high alkalinity. Coupled with waste-to-energy power plant operations, waste incineration fly ash disposal could achieve synergistic optimization and reduce costs while increasing efficiency. Therefore, how to couple waste incineration fly ash disposal with waste-to-energy power plant operations is a pressing problem that needs to be solved. Utility Model Content
[0003] Based on the aforementioned shortcomings of the existing technology, the purpose of this utility model is to provide a waste incineration fly ash treatment system coupled to a waste incineration power plant.
[0004] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:
[0005] A waste-to-power incineration fly ash treatment system coupled with a waste-to-energy plant includes: a pyrolysis furnace, a washing tank, a washing filter press, a de-gravity dosing tank, a de-gravity flocculation tank, a de-gravity sedimentation tank, a heavy metal plate and frame filter press, a hardening reaction tank, a hardening sedimentation tank, and a hardening plate and frame filter press, and a slurry tank. Fly ash generated by the waste-to-energy plant is transported to the pyrolysis furnace for pyrolysis and detoxification. After detoxification, the fly ash enters the washing tank. The washed ash slurry output from the washing tank is filtered by the washing filter press. The filter cake is output to a building materials recycling facility. The filtrate sequentially passes through the de-gravity dosing tank, the de-gravity flocculation tank, and the de-gravity sedimentation tank for sedimentation. The sludge is treated as hazardous waste containing heavy metals and the filtrate from the plate and frame filter press enters the hardening reaction tank. The hardening reaction tank is connected to the leachate output pipeline of the waste-to-energy plant. The filtrate from the plate and frame filter press and the leachate from the waste-to-energy plant are mixed in the hardening reaction tank and then transported to the hardening sedimentation tank for sedimentation. The sediment enters the hardening plate and frame filter press, and the filtrate is connected to the hardening reaction tank through a reuse pipeline. The filter cake is transported to the slurry tank, which is connected to a water inlet pipeline. The filter cake and water are mixed in the slurry tank to obtain slurry, which is then transported to the desulfurization tower of the waste-to-energy plant as a desulfurizing agent.
[0006] As a preferred embodiment, the waste incineration fly ash treatment system also includes a microfiltration system, a neutralization tank, a first-stage nanofiltration system, a nanofiltration concentrate tank, a first-stage nanofiltration product tank, a reverse osmosis system, an evaporation feed tank, and an evaporation crystallizer. The supernatant from the hardening sedimentation tank enters the microfiltration system. The concentrate produced by the microfiltration system is transported to the hardening reaction tank through a return pipeline. The clarified liquid is transported to the neutralization tank, which is then pumped to the first-stage nanofiltration system. The nanofiltration concentrate enters the nanofiltration concentrate tank, and the clarified nanofiltration liquid enters the first-stage nanofiltration product tank. The clarified nanofiltration liquid from the first-stage nanofiltration product tank is pumped to the reverse osmosis system. The reverse osmosis concentrate enters the evaporation feed tank, and the clarified reverse osmosis liquid enters the washing tank. The reverse osmosis concentrate from the evaporation feed tank is pumped to the evaporation crystallizer. The evaporation crystallizer is connected to the steam pipe at the turbine outlet, utilizing the steam at the turbine outlet of the waste incineration power plant for evaporation and crystallization.
[0007] As a preferred embodiment, the nanofiltration concentrate from the nanofiltration concentrate tank is pumped to a two-stage nanofiltration system. The concentrate produced by the two-stage nanofiltration system is connected to the incinerator of the waste-to-energy plant via a return spray pipeline for concentrate return spraying. The clear liquid is transported to the leachate regulating tank, which is connected to the leachate biochemical system of the waste-to-energy plant. The leachate from the leachate biochemical system is treated by an ultrafiltration system and then connected to the leachate output pipeline.
[0008] As a preferred embodiment, the evaporation condensate outlet of the evaporator crystallizer is connected to the slurry tank via a water inlet pipe.
[0009] As a preferred embodiment, the washing tank and the washing filter press are divided into two stages. After detoxification, the fly ash enters the primary washing tank. The washed ash slurry output from the primary washing tank is filtered by the primary washing filter press. The filtrate enters the degravation and chemical addition tank, and the filter cake enters the secondary washing tank. The slurry output from the secondary washing tank is filtered by the secondary washing filter press. The filter cake is output to the building materials resource recovery center, and the filtrate returns to the primary washing tank.
[0010] As a preferred embodiment, the hardening reaction tank is divided into two stages: a primary hardening reaction tank and a secondary hardening reaction tank. The primary hardening reaction tank is connected to the plate and frame filtrate outlet of the heavy metal plate and frame and the leachate output pipeline of the waste incineration power plant, respectively. The secondary hardening reaction tank is used to add hardening agents to further harden the liquid output from the primary hardening reaction tank.
[0011] As a preferred embodiment, the flue gas from the waste heat boiler of the waste incineration power plant is treated by a desulfurization tower and then enters a bag filter for dust removal. After dust removal, the flue gas enters an SCR unit for desulfurization and denitrification. Then, a GGH heat exchanger is used to utilize the waste heat of the desulfurized and denitrified flue gas. Finally, acidic gases are removed by an alkaline scrubbing tower and then discharged into the atmosphere through a chimney.
[0012] As a preferred embodiment, the GGH heat exchanger is divided into a primary GGH heat exchanger and a secondary GGH heat exchanger. The primary GGH heat exchanger is used for primary heat exchange between the flue gas after dust removal and the flue gas after desulfurization and denitrification. The secondary GGH heat exchanger is used for heat exchange between the flue gas after desulfurization and denitrification after primary heat exchange and the flue gas discharged from the alkali washing tower. The flue gas pipeline between the primary GGH heat exchanger and the SCR unit is equipped with a flue gas heater.
[0013] As a preferred embodiment, the pyrolysis tail gas from the pyrolysis furnace is transported to the desulfurization tower via a tail gas pipeline.
[0014] As a preferred embodiment, the pyrolysis furnace is heated by electric heating, gas heating, or high-temperature flue gas heating, wherein the high-temperature flue gas heating is performed using the exhaust gas from the waste heat boiler of a waste incineration power plant.
[0015] As a preferred option, the fly ash generated by the bag filter dust collector is pneumatically conveyed to the pyrolysis furnace.
[0016] Compared with the prior art, the advantages of this utility model are:
[0017] (1) The waste incineration fly ash treatment system coupled to the waste incineration power plant of this utility model utilizes the mixture of alkalinity in the waste leachate and hardness in the water washing filtrate to form calcium carbonate precipitate through chemical reaction, which significantly reduces the cost of reagent use.
[0018] (2) The filter cake generated by the removal of the hard plate frame of this utility model is mixed with the evaporation condensate to form a slurry, which is then used as a desulfurizing agent and recycled to the desulfurization tower to realize the recycling of the product.
[0019] (3) This utility model utilizes steam from the turbine outlet for evaporation and crystallization to achieve the recycling of heat. Attached Figure Description
[0020] Figure 1 This is a flow diagram of a waste incineration fly ash treatment system coupled to a waste incineration power plant according to an embodiment of this utility model. Detailed Implementation
[0021] To more clearly illustrate the embodiments of this utility model, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.
[0022] This utility model discloses a waste incineration fly ash treatment system coupled with a waste incineration power plant. The exhaust gas generated from pyrolysis tail gas enters the waste incineration power plant exhaust gas treatment system and undergoes co-treatment before entering the desulfurization tower. The secondary water washing fly ash slurry, whose main component is quicklime, is used as a desulfurizing agent to spray back onto the desulfurization tower, and the desulfurization adopts a semi-dry method. Taking advantage of the high alkalinity of the leachate from the waste incineration power plant and the high hardness of the fly ash filtrate, the two streams of water are mixed to form calcium carbonate precipitate. To prevent either the hardness or alkalinity of the two streams from being excessive, sodium carbonate and sodium hydroxide are used to balance the mixture. The evaporation system uses steam from the turbine outlet to evaporate and crystallize salt.
[0023] The equipment in the fly ash treatment system of this utility model is all skid-mounted integrated equipment. The core equipment, the low-temperature pyrolysis furnace (hereinafter referred to as "pyrolysis furnace"), has multiple heating methods, including electric heating, gas heating, and high-temperature flue gas heating. Among them, the high-temperature flue gas heating uses the flue gas from the outlet of the waste heat boiler of the waste incineration power plant to realize the utilization of the waste heat of the outlet flue gas of the waste heat boiler.
[0024] This utility model adopts a waste incineration fly ash treatment system coupled with the waste incineration power plant, which can not only solve the problems of high initial construction costs, high reagent and operating costs of traditional fly ash resource utilization enterprises, but also save the overall operating costs of waste incineration power plants. It is low-carbon, environmentally friendly and economically feasible.
[0025] Specifically, such as Figure 1 As shown, the waste incineration fly ash treatment system coupled to the waste incineration power plant in this embodiment of the present invention includes a pyrolysis furnace 1, a primary water washing tank 2, a primary water washing filter press 3, a secondary water washing tank 4, a secondary water washing filter press 5, a heavy metal removal chemical dosing tank 6, a heavy metal removal flocculation tank 7, a heavy metal removal sedimentation tank 8, a heavy metal plate and frame 9, a primary hardening reaction tank 10, a secondary hardening reaction tank 11, a hardening sedimentation tank 12, a hardening plate and frame 13, a slurry tank 14, a microfiltration system 15, a neutralization water tank 16, a primary nanofiltration system 17, a nanofiltration concentrate tank 18, a secondary nanofiltration system 19, a primary nanofiltration product water tank 20, a reverse osmosis system 21, an evaporation feed water tank 22, and an evaporation crystallizer 23.
[0026] The flow path of the waste-to-energy power plant section in this embodiment of the utility model is the existing flow path: the flue gas from the outlet of the waste heat boiler A of the waste-to-energy power plant is treated by the desulfurization tower B and then enters the bag filter C for dust removal. After dust removal, the flue gas enters the SCR unit G for desulfurization and denitrification. Then, the waste heat of the desulfurized and denitrified flue gas is utilized by the GGH heat exchanger. Finally, acidic gases are removed by the alkaline scrubbing tower J and then discharged into the atmosphere through the chimney K. Specifically, the GGH heat exchanger is divided into a primary GGH heat exchanger E and a secondary GGH heat exchanger H. The primary GGH heat exchanger G is used for primary heat exchange between the dust-removed flue gas and the desulfurized and denitrified flue gas. The secondary GGH heat exchanger H is used for heat exchange between the desulfurized and denitrified flue gas after the primary heat exchange and the flue gas discharged from the alkaline scrubbing tower J. Among them, the flue gas pipeline between the primary GGH heat exchanger E and the SCR unit G is equipped with a flue gas heater F, which heats the flue gas to meet the denitrification temperature requirements. In addition, waste incineration power plants also include a leachate biochemical system L and an ultrafiltration system M, which can be referred to in existing technologies and will not be elaborated here.
[0027] The fly ash generated by the bag filter C is pneumatically conveyed to the buffer bin 0 via the pneumatic conveying equipment D. The fly ash is then fed into the pyrolysis furnace 1. The pyrolysis furnace 1 has multiple heating methods, including electric heating, gas heating, and high-temperature flue gas heating. The fly ash is detoxified by low-temperature pyrolysis of dioxins in the fly ash at a temperature of 350-400℃ and in an oxygen-free atmosphere. After detoxification, the fly ash enters the primary washing tank 2. The slurry from the primary washing tank 2 is filtered by the primary washing filter press 3. The filtrate enters the de-gravity addition tank 6, and the filter cake enters the secondary washing tank 4. The slurry from the secondary washing tank 4 is filtered by the secondary washing filter press 5. The filter cake 50 is output to the building materials resource utilization, and the filtrate returns to the primary washing tank 2.
[0028] In the heavy metal dosing tank 6, PAM / PAC / sodium sulfide is added for reaction, and then the mixture enters the heavy metal flocculation tank 7 for flocculation. It then passes through the heavy metal sedimentation tank 8 for sedimentation, and the sediment enters the heavy metal plate and frame sludge tank 9. The resulting sludge 90 is treated as hazardous heavy metal waste. The filtrate from the plate and frame sludge tank enters the primary hardening reaction tank 10, which is connected to the leachate output pipeline U of the waste-to-energy incineration plant. The filtrate from the plate and frame sludge tank and the leachate from the waste-to-energy incineration plant are mixed in the primary hardening reaction tank 10 for hardening reaction.
[0029] Ca(OH)2+Ca(HCO3)2=2CaCO3↓+2H2O;
[0030] Then it is transported to the secondary hardening reaction tank 11, where sodium carbonate and sodium hydroxide Q are added to remove the remaining hardness and alkalinity in the water; next, it is transported to the hardening sedimentation tank 12 for sedimentation, and the sediment enters the hardening plate and frame 13. The filtrate produced by the hardening plate and frame 13 is connected to the primary hardening reaction tank 10 through the reuse pipeline. The filter cake produced by the hardening plate and frame 13 is transported to the slurry tank 14. The slurry tank 14 is connected to the water inlet pipeline Z. The filter cake and water are mixed in the slurry tank 14 to obtain slurry. The slurry is used as desulfurizing agent R and transported to the desulfurization tower B of the waste incineration power plant.
[0031] The supernatant from the aforementioned hardening sedimentation tank 12 enters the microfiltration system 15. The concentrated liquid produced by the microfiltration system 15 is transported to the primary hardening reaction tank 10 through the return liquid pipeline. The clarified liquid is transported to the neutralization tank 16. The neutralization tank 16 is pumped to the first-stage nanofiltration system 17. The concentrated liquid produced by nanofiltration enters the nanofiltration concentrate tank 18. The clarified liquid produced by nanofiltration enters the first-stage nanofiltration product tank 20. The clarified liquid from the first-stage nanofiltration product tank 20 is pumped to the reverse osmosis system 21. The concentrated liquid produced by reverse osmosis enters the evaporation feed tank 22. The clarified liquid S produced by reverse osmosis enters the primary water washing tank 2 and the secondary water washing tank 4. The concentrated liquid from the evaporation feed tank 22 is pumped to the evaporator crystallizer 23. The evaporator crystallizer 23 is connected to the turbine outlet steam pipeline N. Evaporation crystallization is carried out using the turbine outlet steam of the waste incineration power plant. The resulting product salt V is transported off-site.
[0032] The concentrate from the nanofiltration concentrate tank 18 is pumped to the second-stage nanofiltration system 19. The concentrate W produced by the second-stage nanofiltration system 19 is connected to the incinerator of the waste-to-energy plant via a return spray pipeline for concentrate return spraying. The clear liquid T produced by the second-stage nanofiltration system 19 is transported to the leachate equalization tank 24. The leachate equalization tank 24 is connected to the leachate biochemical system L of the waste-to-energy plant. The leachate from the leachate biochemical system is treated by the ultrafiltration system M and then connected to the leachate output pipeline U.
[0033] The evaporation condensate outlet Z of the aforementioned evaporator crystallizer 23 is connected to the slurry tank 14 via a water inlet pipe.
[0034] In addition, the pyrolysis tail gas from pyrolysis furnace 1 is transported to desulfurization tower B through tail gas pipeline X, meaning that the pyrolysis tail gas undergoes co-treatment before entering the desulfurization tower in the waste incineration power plant exhaust gas treatment system.
[0035] The above description is only a detailed explanation of the preferred embodiments and principles of this utility model. For those skilled in the art, there may be changes in the specific implementation methods based on the ideas provided by this utility model, and these changes should also be considered within the protection scope of this utility model.
Claims
1. A waste incineration fly ash treatment system coupled to a waste incineration power plant, characterized in that, include: The system includes a pyrolysis furnace, washing tank, washing filter press, degreasing agent dosing tank, degreasing flocculation tank, degreasing sedimentation tank, heavy metal plate and frame filter press, hardening reaction tank, hardening sedimentation tank, hardening plate and frame filter press, and slurry tank. Fly ash from the waste-to-energy incineration plant is transported to the pyrolysis furnace for degreasing and detoxification. After detoxification, the fly ash enters the washing tank. The washed ash slurry output from the washing tank is filtered by the washing filter press. The filter cake is output to the building materials recycling center. The filtrate sequentially passes through the degreasing agent dosing tank, the degreasing flocculation tank, and the degreasing sedimentation tank for sedimentation. The sediment then enters the heavy metal plate and frame filter press. Sludge is treated as hazardous waste containing heavy metals. The filtrate from the plate and frame filter press enters the hardening reaction tank, which is connected to the leachate output pipeline of the waste-to-energy power plant. The filtrate from the plate and frame filter press and the leachate from the waste-to-energy power plant are mixed in the hardening reaction tank and then transported to the hardening sedimentation tank for sedimentation. The sediment enters the hardening plate and frame filter press, and the filtrate is connected to the hardening reaction tank through a reuse pipeline. The filter cake is transported to the slurry tank, which is connected to a water inlet pipeline. The filter cake and water are mixed in the slurry tank to obtain slurry, which is then transported to the desulfurization tower of the waste-to-energy power plant as a desulfurizing agent.
2. The waste incineration fly ash treatment system according to claim 1, characterized in that, It also includes a microfiltration system, a neutralization tank, a first-stage nanofiltration system, a nanofiltration concentrate tank, a first-stage nanofiltration permeate tank, a reverse osmosis system, an evaporation feed tank, and an evaporation crystallizer. The supernatant from the hardening sedimentation tank enters the microfiltration system. The concentrate produced by the microfiltration system is transported to the hardening reaction tank through a return pipeline. The supernatant is transported to the neutralization tank. The neutralization tank is pumped to the first-stage nanofiltration system. The nanofiltration concentrate enters the nanofiltration concentrate tank. The nanofiltration supernatant enters the first-stage nanofiltration permeate tank. The nanofiltration supernatant from the first-stage nanofiltration permeate tank is pumped to the reverse osmosis system. The reverse osmosis concentrate enters the evaporation feed tank. The reverse osmosis supernatant enters the water washing tank. The reverse osmosis concentrate from the evaporation feed tank is pumped to the evaporation crystallizer. The evaporation crystallizer is connected to the steam pipe at the turbine outlet and uses the steam at the turbine outlet of the waste incineration power plant for evaporation and crystallization.
3. The waste incineration fly ash treatment system according to claim 2, characterized in that, The nanofiltration concentrate from the nanofiltration concentrate tank is pumped to the second-stage nanofiltration system. The concentrate produced by the second-stage nanofiltration system is connected to the incinerator of the waste-to-energy plant via a return spray pipeline for concentrate return spraying. The clear liquid is transported to the leachate equalization tank, which is connected to the leachate biochemical system of the waste-to-energy plant. The leachate from the leachate biochemical system is treated by the ultrafiltration system and then connected to the leachate output pipeline.
4. The waste incineration fly ash treatment system according to claim 2, characterized in that, The evaporation condensate outlet of the evaporator crystallizer is connected to the slurry tank via a water inlet pipe.
5. The waste incineration fly ash treatment system according to any one of claims 1-4, characterized in that, The washing tank and the washing filter press are divided into two stages. After detoxification, the fly ash enters the first-stage washing tank. The washed ash slurry output from the first-stage washing tank is filtered by the first-stage washing filter press. The filtrate enters the degravation and chemical addition tank, and the filter cake enters the second-stage washing tank. The slurry output from the second-stage washing tank is filtered by the second-stage washing filter press. The filter cake is output to the building materials resource recovery center, and the filtrate returns to the first-stage washing tank.
6. The waste incineration fly ash treatment system according to any one of claims 1-4, characterized in that, The hardening reaction tank is divided into two stages: a primary hardening reaction tank and a secondary hardening reaction tank. The primary hardening reaction tank is connected to the plate and frame filtrate outlet of the heavy metal plate and frame and the leachate output pipeline of the waste incineration power plant, respectively. The secondary hardening reaction tank is used to add hardening agents to further harden the liquid output from the primary hardening reaction tank.
7. The waste incineration fly ash treatment system according to any one of claims 1-4, characterized in that, The flue gas from the waste heat boiler of the waste incineration power plant is treated by a desulfurization tower and then enters a bag filter for dust removal. After dust removal, the flue gas enters an SCR unit for desulfurization and denitrification. Then, a GGH heat exchanger is used to utilize the waste heat of the desulfurized and denitrified flue gas. Finally, acidic gases are removed by an alkaline scrubbing tower and then discharged into the atmosphere through a chimney.
8. The waste incineration fly ash treatment system according to claim 7, characterized in that, The GGH heat exchanger is divided into a primary GGH heat exchanger and a secondary GGH heat exchanger. The primary GGH heat exchanger is used for heat exchange between the flue gas after dust removal and the flue gas after desulfurization and denitrification. The secondary GGH heat exchanger is used for heat exchange between the flue gas after desulfurization and denitrification after the primary heat exchange and the flue gas discharged from the alkali washing tower. The flue gas pipeline between the primary GGH heat exchanger and the SCR unit is equipped with a flue gas heater.
9. The waste incineration fly ash treatment system according to claim 7, characterized in that, The pyrolysis tail gas from the pyrolysis furnace is transported to the desulfurization tower via a tail gas pipeline.
10. The waste incineration fly ash treatment system according to claim 7, characterized in that, The pyrolysis furnace is heated by electricity, gas, or high-temperature flue gas. The high-temperature flue gas heating method uses the exhaust gas from the waste heat boiler of the waste incineration power plant.