Device system for synergistically treating multiple pollutants in waste incineration flue gas

Abstract

The utility model provides a device system for synergistically treating multiple pollutants in waste incineration flue gas. The device system comprises a boiler, a desulfurizing tower, a settling chamber and a multi-pollutant integrated treatment device which are connected in sequence, the multi-pollutant integrated treatment device comprises a first ash hopper, a dust removal chamber and a gas purification chamber which are sequentially arranged from bottom to top; a flue gas inlet is formed in one side of the dust removal chamber; a composite filter cartridge is arranged in the dust removal chamber; a flue gas outlet is formed in one side of the gas purification chamber; the composite filter cartridge is made of ceramic fibers internally coated with a catalyst; and an ash removal device is further arranged on the outer side of the air purification chamber. According to the device system, dry desulfurization is coupled with the composite filter cartridge for filtration, so that integrated cooperative treatment of pollutants such as dust, heavy metal, nitric oxide and dioxin in waste incineration flue gas is realized, the investment and operation cost of a waste incineration flue gas treatment system can be reduced, and the device system is suitable for large-scale popularization and application.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas treatment, in particular to a device system for synergistic treatment of multiple pollutants in waste incineration flue gas. Background Technique

[0002] The current waste incineration flue gas treatment system mainly consists of "selective non-catalytic reduction denitrification (SNCR)+semi-dry desulfurization+activated carbon injection+bag dust removal". The treatment system adopts a series-integrated combination method of single-function equipment. The treatment process of this system is that the flue gas fully contacts and reacts with the denitrification reducing agent in the high-temperature environment of the boiler to achieve selective non-catalytic reduction denitrification. Then the flue gas enters the desulfurization tower and contacts and reacts with the desulfurizing agent to achieve desulfurization (acid). Next, the flue gas contacts and reacts with the injected fluidized activated carbon powder when passing through the flue to achieve dioxin adsorption. Finally, the flue gas mixed with various dusts realizes the removal of dust under the interception and filtration of the filter bag, so as to achieve dust removal, desulfurization, denitrification and dioxin removal. The fly ash intercepted and filtered by the bag (containing dioxin, activated carbon powder, desulfurization by-products, heavy metals, etc.) is collected by the ash conveying system and sent to the hazardous waste treatment center to be mixed with the chelating agent. Through chelating treatment, heavy metals and toxic and harmful pollutants are fixed and stabilized, and then transported to the fly ash temporary storage room. After passing the inspection of various indicators, it is sent to the landfill for safe landfill.

[0003] The current method of treating waste incineration flue gas uses a series connection of single-function devices. Its system is huge and complex, occupying a large area. Simply modifying the original equipment can no longer meet the increasing demand for flue gas treatment. Generally, an SCR denitration device needs to be added after bag dust removal, and in some projects, a wet acid removal tower is also added in series for desulfurization (acid). Taking the third-phase project of the Haikou Municipal Solid Waste Incineration Power Plant as an example, its waste incineration production line is equipped with a combined flue gas purification process of "semi-dry desulfurization + dry desulfurization + activated carbon adsorption + bag dust removal + wet acid removal + SCR denitration". Such modifications can meet more stringent flue gas pollutant emission requirements, but generally have the following problems: ① The floor area, construction cost, and operating cost increase sharply. The system is huge and redundant, with a very large amount of operation and maintenance, and low economy and competitiveness; ② In order to meet the reaction temperature windows of SCR denitration and wet acid removal, the flue gas needs to be heated and cooled through heat exchange equipment, resulting in a large equipment investment and maintenance workload, and high heat energy loss of the flue gas; ③ The wet acid removal process is complex and has many supporting devices. The wastewater contains high-concentration inorganic chlorides and heavy metals, with high operation and maintenance and treatment costs; ④ The "activated carbon adsorption + bag interception" dioxin technology only adsorbs and transfers gaseous dioxins in solid form to the activated carbon and then intercepts them through the filter bag, without achieving the complete degradation of dioxins. The fly ash containing dioxins captured needs to be strictly disposed of as hazardous waste, with high treatment costs; ⑤ Due to the relatively low operating temperature range of the bag system, the activated carbon will provide a carbon source for the low-temperature catalytic synthesis of dioxins, causing the desorption of dioxins from the residual carbon at the ash accumulation sites such as the flue duct wall, increasing the total amount of dioxin emissions; ⑥ After the activated carbon is sprayed into the flue duct, it is mixed with fly ash and desulfurization (acid) by-products. The proportion of activated carbon powder in the mixture is very small (about 5% or so). In fact, the contact and adsorption opportunities between gaseous dioxins in the flue gas and the activated carbon powder are few, and even some micropores of the activated carbon will be blocked by substances such as fly ash. Moreover, due to the high concentrations of fly ash and desulfurization (acid) by-products, the ash cleaning cycle of the bag filter is short, resulting in a short residence time of the activated carbon powder on the filter bag surface, reducing the utilization rate of the activated carbon and increasing the operating cost of dioxin adsorption. ⑦ Core components such as bags and SCR catalysts are prone to a series of problems such as bag rupture, corrosion, and catalyst poisoning under the complex conditions of waste incineration, with a short service life. Generally, after 2 - 3 years of basic service life, the core components need to be replaced, and the operation and maintenance costs are high.

[0004] Therefore, it is of great significance to develop a flue gas treatment device system that can achieve efficient purification of flue gas, has a small floor area, and low treatment costs. Utility Model Content

[0005] In view of the problems existing in the prior art, the present utility model provides a device system for the collaborative treatment of multiple pollutants in waste incineration flue gas. By coupling dry desulfurization with composite filter cartridge filtration, it realizes the integrated collaborative treatment of pollutants such as dust, heavy metals, nitrogen oxides, and dioxins in waste incineration flue gas, can reduce the investment and operating costs of the flue gas treatment system, and is suitable for large-scale popularization and application.

[0006] To achieve this purpose, the present utility model adopts the following technical solutions:

[0007] The present utility model provides a device system for the collaborative treatment of multiple pollutants in waste incineration flue gas. The device system includes a boiler, a desulfurization tower, a sedimentation chamber, and a multi-pollutant integrated treatment device connected in sequence;

[0008] The multi-pollutant integrated treatment device includes a first ash hopper, a first dust removal chamber, and a clean gas chamber arranged in sequence from bottom to top; a flue gas inlet is arranged on one side of the first dust removal chamber; a composite filter cartridge is arranged in the first dust removal chamber; a flue gas outlet is arranged on one side of the clean gas chamber; the composite filter cartridge is a ceramic fiber coated with a catalyst inside; a first ash cleaning device is further arranged outside the clean gas chamber.

[0009] After the waste is incinerated in the boiler in the device system for the collaborative treatment of multiple pollutants in waste incineration flue gas of the present utility model, it enters the desulfurization tower for desulfurization, then enters the sedimentation chamber to remove large particles in the flue gas, and finally enters the composite filter cartridge to filter out solid pollutants such as dust, heavy metals, and desulfurization by-products. The solid pollutants are efficiently filtered and intercepted by the surface layer of the composite filter cartridge. Subsequently, the flue gas slowly passes through the filter cartridge wall, and nitrogen oxides come into full contact with the catalyst and react quickly and efficiently with the denitration agent to generate nitrogen and water. At the same time, gaseous dioxins are destructed by oxygen under the action of the catalyst, undergo a structural transformation, and are oxidized and cracked into H 2 O, HCl, and CO 2 , without the need to add additional adsorbents, truly realizing the efficient decomposition and removal of dioxins. The composite filter cartridge effectively avoids the erosion, abrasion of the catalyst by dust, and the poisoning of the catalyst by heavy metals, and prolongs the service life of the catalyst.

[0010] The catalyst used in the composite filter cartridge of the present utility model is an existing catalyst that can achieve efficient denitration and dioxin removal. Utilizing the synergistic promotion mechanism of nitrogen oxide reduction and dioxin oxidation can promote the cleavage of the C-CL bond of dioxins, thereby improving the oxidation decomposition efficiency of dioxins, realizing the efficient oxidation decomposition of dioxins, without the need to add additional dioxin adsorbents, with high system integration and strong economy. The composite filter cartridge selects an existing filter cartridge with a wide applicable window temperature, high temperature resistance, high strength, acid and alkali corrosion resistance, and a long service life. Therefore, there is no need to frequently stop the machine to replace the core components, reducing the operation and maintenance volume and cost of the device system.

[0011] The desulfurization tower, settling chamber and multi-pollutant integrated treatment device described in the utility model can directly treat the flue gas discharged from the economizer section of the boiler without the need for repeated heating and cooling through heat exchange equipment. Compared with the prior art, the system flow of the device is streamlined, the resistance is low, and the loss to the induced draft fan is small.

[0012] Preferably, the boiler comprises a combustion chamber, a superheater and an economizer which are sequentially arranged along the flue gas flow direction.

[0013] Preferably, the superheater is connected to the steam generator via a hot steam pipeline.

[0014] Preferably, the desulfurization tower comprises a horizontal flue gas conveying pipeline, a venturi section and a reaction zone which are arranged in sequence from bottom to top.

[0015] Preferably, an ammonia spraying device and a high-efficiency mixer are sequentially arranged in the horizontal flue gas conveying pipeline.

[0016] In the utility model, the waste incineration flue gas enters the desulfurization tower, contacts and reacts with the desulfurizer introduced in a fluidized manner above the venturi section to achieve desulfurization, and then the flue gas is mixed with ammonia formed by an ammonia injection device in the flue under the action of a high-efficiency mixer.

[0017] Preferably, the Venturi section consists of a contraction section, a Venturi throat and a diffusion section which are arranged in sequence from bottom to top.

[0018] Preferably, the venturi throat is connected to a desulfurizer feeding device, and the desulfurizer is fed into the venturi throat through the desulfurizer feeding device. A fluidized bed is formed in the reaction zone under the action of the venturi effect, and the flue gas and the desulfurizer are fully mixed in the reaction zone, while the reaction time is also increased.

[0019] The desulfurizer used in the utility model can select the existing calcium-based desulfurizer, sodium-based desulfurizer, high-activity desulfurizer or a mixture of multiple desulfurizers according to the temperature window and the desulfurization efficiency requirements.

[0020] Preferably, the desulfurizing agent feeding device consists of an ash storage bin, a spiral feeder and a fluidizing trough which are arranged in sequence from top to bottom.

[0021] The desulfurization tower of the utility model can improve the desulfurization efficiency, reduce material consumption, and finally achieve SO 2 Ultra-low emission standards.

[0022] Preferably, the settling chamber includes a guide device, a second dust removal chamber and an ash blocking device which are arranged in sequence along the flue gas flow direction, wherein the guide device is used to change the direction of the garbage incineration flue gas and distribute the flue gas evenly; the ash blocking device can effectively prevent the fallen dust from being re-carried by the flue gas.

[0023] Preferably, the second dust removal chamber is composed of a dust collection device and a second dust cleaning device. The function of the dust collection device is to separate large particulate dust in the flue gas; the second dust cleaning device cleans the dust into the second ash hopper.

[0024] Preferably, a second ash hopper is arranged below the second dust removal chamber for collecting solid pollutants such as filtered dust.

[0025] Through the above-mentioned combination of devices and equipment, the sedimentation chamber of the present utility model can greatly reduce the dust concentration in the flue gas and improve the service life of subsequent equipment.

[0026] Preferably, a perforated plate is arranged between the clean gas chamber and the first dust removal chamber.

[0027] Preferably, a pressing plate and a shoulder bolt are placed on the perforated plate.

[0028] Preferably, sealing fasteners are arranged around the perforated plate.

[0029] The perforated plate, pressing plate, shoulder bolt and sealing fastener of the present utility model can well fix the composite filter cartridge, so that the waste incineration flue gas can only enter the clean gas chamber after passing through the composite filter cartridge. By virtue of the good sieving and intercepting functions of the composite filter cartridge and the action of the catalyst, the pollutants such as dust, heavy metals, nitrogen oxides and dioxins in the waste incineration flue gas can reach the ultra-low emission index of the waste incineration flue gas.

[0030] Preferably, the first dust cleaning device is composed of an air bag, a pulse valve and a blowpipe. The first dust cleaning device sprays compressed gas for dust cleaning during dust cleaning.

[0031] The solid pollutants such as dust collected by the first ash hopper and the second ash hopper of the present utility model are sent to the harmless treatment device through the ash conveying system at the bottom of the ash hopper.

[0032] The operation method of the device system for synergistic treatment of multiple pollutants in the waste incineration flue gas of the present utility model includes:

[0033] The waste is incinerated in the boiler to generate waste incineration flue gas at about 200°C - 250°C, which enters the desulfurization tower and is mixed and reacted with the added desulfurizing agent. Acidic substances such as SO 2 , HCl in the flue gas are removed; then the flue gas enters the sedimentation chamber to remove large particles in the flue gas, and finally enters the composite filter cartridge for filtration to remove solid pollutants such as dust, heavy metals and desulfurization by-products in it. The flue gas slowly passes through the filter cartridge wall, and nitrogen oxides and dioxins in the flue gas are catalytically removed under the action of the catalyst.

[0034] Compared with the prior art, the present utility model has at least the following beneficial effects:

[0035] The device system for collaborative treatment of multiple pollutants in waste incineration flue gas provided by the present utility model realizes the collaborative treatment of multiple pollutants such as dust removal, heavy metal removal, desulfurization, denitrification and dioxin removal in waste incineration flue gas, simplifies the system process, reduces the system maintenance workload, effectively reduces the system floor area, reduces the system pressure loss, and saves the investment cost of process equipment; the treated flue gas does not need to be subjected to secondary environmental protection treatment, meeting the development trend of ultra-low emission of waste incineration flue gas in the future. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the device system for collaborative treatment of multiple pollutants in waste incineration flue gas in the specific embodiment of the present utility model.

[0037] Figure 2 It is a schematic diagram of the boiler structure.

[0038] Figure 3 It is a schematic diagram of the desulfurization tower structure.

[0039] Figure 4 It is a schematic diagram of the sedimentation chamber structure.

[0040] Figure 5 It is a schematic diagram of the structure of the multi-pollutant integrated device.

[0041] Figure 6 It is a schematic top view of the structure at the composite filter cartridge perforated plate.

[0042] Figure 7 It is a schematic side view of the structure at the composite filter cartridge perforated plate.

[0043] In the figure: 1 - boiler; 11 - incineration chamber; 12 - superheater; 13 - economizer; 14 - steam generator;

[0044] 2 - desulfurization tower; 21 - ammonia injection device; 22 - high-efficiency mixer; 23 - Venturi section; 231 - contraction section; 232 - Venturi throat; 233 - diffusion section; 24 - reaction zone; 25 - desulfurizer feeding device; 251 - ash storage bin; 252 - spiral feeder; 253 - fluidized bed;

[0045] 3 - sedimentation chamber; 31 - guiding device; 32 - second dust removal chamber; 321 - ash collection device; 322 - second ash cleaning device; 33 - ash blocking device; 34 - second ash hopper;

[0046] 4 - multi-pollutant integrated device; 41 - composite filter cartridge; 42 - clean gas chamber; 43 - first dust removal chamber; 44 - perforated plate; 441 - pressing plate; 442 - shoulder bolt; 443 - sealing fastener; 45 - first ash cleaning device; 451 - air bag; 452 - pulse valve and blowpipe; 46 - first ash hopper;

[0047] 5 - flue. Detailed implementation manners

[0048] The technical solution of the present utility model will be further described below in conjunction with the accompanying drawings and through specific implementation manners.

[0049] The present utility model will be further described in detail below. However, the following examples are only simple examples of the present utility model and do not represent or limit the scope of the protection of the present utility model. The scope of protection of the present utility model shall be subject to the claims.

[0050] It should be understood that in the description of the present utility model, the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0051] It should be noted that in the description of the present utility model, unless otherwise clearly defined and limited, the terms "set", "connected", "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood through specific situations.

[0052] As a specific implementation manner of the present utility model, a device system for co-governing multiple pollutants in waste incineration flue gas is provided, and its schematic diagram is as Figure 1 shown.

[0053] The device system includes a boiler 1, a desulfurization tower 2, a sedimentation chamber 3, and a multi-pollutant integrated treatment device 4 that are connected in sequence; each device is connected by a flue 5.

[0054] The structural schematic diagram of the boiler 1 is as Figure 2 shown.

[0055] The boiler 1 includes an incineration chamber 11, a superheater 12, and an economizer 13 that are sequentially arranged along the flue gas flow direction; the superheater 12 is connected to a steam generator 14 through a superheated steam pipeline.

[0056] The structural schematic diagram of the desulfurization tower 2 is as Figure 3 shown.

[0057] The desulfurization tower 2 includes a horizontal flue gas conveying pipeline, a Venturi section 23, and a reaction zone 24 that are sequentially arranged from bottom to top. An ammonia injection device 21 and an efficient mixer 22 are sequentially arranged in the horizontal flue gas conveying pipeline.

[0058] The Venturi section 23 is composed of a contraction section 231, a Venturi throat 232, and a diffusion section 233 that are sequentially arranged from bottom to top; the Venturi throat 232 is connected to a desulfurizing agent feeding device 25.

[0059] The desulfurizing agent feeding device 25 is composed of an ash storage bin 251, a spiral feeder 252, and a fluidized bed 253 that are sequentially arranged from top to bottom.

[0060] The structural schematic diagram of the sedimentation chamber 3 is as Figure 4 shown.

[0061] The sedimentation chamber 3 includes a guiding device 31, a second dust removal chamber 32, and an ash blocking device 33 that are sequentially arranged along the flue gas flow direction.

[0062] The second dust removal chamber 32 is composed of an ash collection device 321 and a second ash cleaning device 322; a second ash hopper 34 is arranged below the second dust removal chamber 32.

[0063] The structural schematic diagram of the multi-pollutant integrated treatment device 4 is as Figure 5 shown.

[0064] The multi-pollutant integrated treatment device 4 includes a first ash hopper 46, a first dust removal chamber 43, and a clean gas chamber 42 that are sequentially arranged from bottom to top; a flue gas inlet is arranged on one side of the first dust removal chamber 43; a composite filter cartridge 41 is arranged in the first dust removal chamber 43; a flue gas outlet is arranged on one side of the clean gas chamber 42; the composite filter cartridge 41 is a ceramic fiber internally coated with a catalyst; a first ash cleaning device 45 is also arranged outside the clean gas chamber 42.

[0065] The structural schematic top view of the composite filter cartridge 41 at the flower plate 44 is as Figure 6 shown, and the side view is as Figure 7 shown.

[0066] A flower plate 44 is arranged between the clean gas chamber 42 and the first dust removal chamber 43; a pressing plate 441 and a shoulder bolt 442 are placed on the flower plate 44; a sealing fastener 443 is arranged around the flower plate 44.

[0067] The first dust cleaning device 45 is composed of an air bag 451, a pulse valve, and a blowpipe 452.

[0068] The flue gas outlet of the clean gas chamber 42 is connected to the economizer 13 and the chimney in sequence through a flue.

[0069] The device system for collaborative treatment of multiple pollutants in waste incineration flue gas described in the present utility model has a high treatment efficiency for pollutants in waste incineration flue gas. The clean flue gas discharged does not need secondary environmental protection treatment and can meet the national ultra-low emission requirements, having a broad prospect for large-scale popularization and application.

[0070] The applicant declares that the present utility model uses the above embodiments to illustrate the detailed structural features of the present utility model. However, the present utility model is not limited to the above detailed structural features, that is, it does not mean that the present utility model must rely on the above detailed structural features to be implemented. Those skilled in the art should understand that any improvement to the present utility model, the equivalent replacement of the components selected by the present utility model, the addition of auxiliary components, and the selection of specific methods, etc., all fall within the protection scope and the disclosure scope of the present utility model.

[0071] The preferred embodiments of the present utility model have been described in detail above. However, the present utility model is not limited to the specific details in the above embodiments. Within the technical concept scope of the present utility model, various simple modifications can be made to the technical solution of the present utility model, and these simple modifications all belong to the protection scope of the present utility model.

Claims

1. A device system for collaboratively treating multiple pollutants in waste incineration flue gas, characterized in that: The device system comprises a boiler (1), a desulfurization tower (2), a settling chamber (3) and a multi-pollutant integrated treatment device (4) which are connected in sequence; The multi-pollutant integrated treatment device (4) comprises a first ash hopper (46), a first dust removal chamber (43) and a clean air chamber (42) which are arranged in sequence from bottom to top; a smoke inlet is arranged on one side of the first dust removal chamber (43); a composite filter cartridge (41) is arranged in the first dust removal chamber (43); a smoke outlet is arranged on one side of the clean air chamber (42); the composite filter cartridge (41) is a ceramic fiber with a catalyst coated inside; and a first ash cleaning device (45) is also arranged on the outside of the clean air chamber (42).

2. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 1 is characterized in that: The boiler (1) comprises a combustion chamber (11), a superheater (12) and an economizer (13) which are arranged in sequence along the flow direction of the flue gas; The superheater (12) is connected to a steam generator (14) via a hot steam pipeline.

3. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 1 is characterized in that: The desulfurization tower (2) comprises a horizontal flue gas conveying pipeline, a venturi section (23) and a reaction zone (24) which are arranged in sequence from bottom to top.

4. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 3 is characterized in that: An ammonia spraying device (21) and a high-efficiency mixer (22) are sequentially arranged in the horizontal flue gas conveying pipeline.

5. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 3 is characterized in that: The Venturi section (23) is composed of a contraction section (231), a Venturi throat (232) and a diffusion section (233) which are arranged in sequence from bottom to top; The venturi throat (232) is connected to the desulfurizing agent feeding device (25).

6. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 5 is characterized in that: The desulfurizing agent feeding device (25) is composed of an ash storage bin (251), a spiral feeder (252) and a fluidizing trough (253) which are arranged in sequence from top to bottom.

7. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 1 is characterized in that: The settling chamber (3) comprises a flow guide device (31), a second dust removal chamber (32) and an ash blocking device (33) which are sequentially arranged along the flow direction of the smoke.

8. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 7 is characterized in that: The second dust removal chamber (32) is composed of a dust collecting device (321) and a second dust cleaning device (322); A second ash hopper (34) is provided below the second dust removal chamber (32).

9. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 1 is characterized in that: A flower plate (44) is provided between the clean air chamber (42) and the first dust removal chamber (43); A pressure plate (441) and a shoulder bolt (442) are placed on the flower plate (44); The flower plate (44) is provided with sealing and restraining parts (443) around its periphery; The first dust cleaning device (45) is composed of an air bag (451), a pulse valve and a spray pipe (452).

10. The device system for coordinated treatment of multiple pollutants in waste incineration flue gas according to claim 1 is characterized in that: The flue gas outlet of the clean air chamber (42) is connected to the economizer (13) and the chimney in sequence through the flue (5).

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