Waste cracking tail gas treatment device

Abstract

The utility model provides a waste cracking tail gas treatment device. The waste cracking tail gas treatment device comprises a bag-type dust collector, a washing tower, a desulfurizing tower, a dry filter and an activated carbon device, the waste cracking tail gas enters the bag-type dust collector from a gas inlet of the bag-type dust collector, a gas outlet of the bag-type dust collector is communicated with a gas inlet of the washing tower, a gas outlet of the washing tower is communicated with a gas inlet of the desulfurizing tower, a gas outlet of the desulfurizing tower is communicated with a gas inlet of the dry filter, and a gas outlet of the dry filter is communicated with a gas inlet of the activated carbon device. Heavy metal substances such as mercury in the tail gas are removed through the washing tower and the activated carbon device, so that the problem that the mercury content of the tail gas discharged into the atmosphere exceeds the standard is solved; intercepting particulate matters in the tail gas through filtering equipment such as a bag-type dust collector and a dry filter; pollutants such as acidic substances, nitrogen oxides and carbon monoxide in the tail gas are removed through the desulfurization tower, the carbon monoxide removal device and the oxynitride treatment device, and finally the tail gas reaches the standard and is discharged.

Description

Technical Field

[0001] This utility model relates to the field of solid waste treatment technology, specifically to a waste pyrolysis tail gas treatment device. Background Technology

[0002] Direct combustion of solid waste produces large amounts of toxic and harmful gases such as sulfides, nitrogen oxides, dioxins, and dust, severely polluting the environment. Pyrolysis technology can remove dioxins from fly ash. The pyrolysis process also generates complex exhaust gases, mainly containing sulfides, nitrogen oxides, particulate matter, acidic substances, heavy metals such as mercury, and other heavy metals.

[0003] A Chinese patent with publication number CN111943623A discloses a method for low-temperature pyrolysis and resource utilization of fly ash from municipal solid waste incineration. The method includes: unloading fly ash from a storage tank and sending it to a pyrolysis furnace for low-temperature pyrolysis; then discharging it from the pyrolysis furnace, detecting the total residual amount of dioxins in the fly ash pyrolysis products, sending fly ash pyrolysis products with a residual amount exceeding 50 ng-TEQ / kg back to the pyrolysis furnace for further pyrolysis, and preparing qualified fly ash pyrolysis products with a residual amount not exceeding 50 ng-TEQ / kg into mine filler; the mine filler is prepared by mixing a binder, aggregate, water, and additives, the binder being prepared by homogenizing qualified fly ash pyrolysis products, slag, furnace slag, and industrial by-product gypsum; the flue gas generated in the pyrolysis furnace sequentially enters a secondary combustion chamber, a waste heat recovery system, a deacidification system, and a dust removal system until the air pollutants in the flue gas meet national emission standards before being discharged.

[0004] Existing exhaust gas treatment devices do not remove heavy metals such as mercury from the exhaust gas, and the pollutants still present after exhaust gas treatment may not meet national environmental emission standards. Utility Model Content

[0005] In view of the deficiencies in the existing technology, the purpose of this utility model is to provide a waste pyrolysis tail gas treatment device.

[0006] According to the present invention, a waste pyrolysis tail gas treatment device includes a bag filter, a scrubbing tower, a desulfurization tower, a dry filter, and an activated carbon device.

[0007] The waste pyrolysis tail gas enters the bag filter from the inlet of the bag filter. The outlet of the bag filter is connected to the inlet of the scrubbing tower. The outlet of the scrubbing tower is connected to the inlet of the desulfurization tower. The outlet of the desulfurization tower is connected to the inlet of the dry filter. The outlet of the dry filter is connected to the inlet of the activated carbon device.

[0008] Preferably, it also includes an electric heater, a carbon monoxide removal device, and a nitrogen oxide removal device;

[0009] The outlet of the activated carbon device is connected to the inlet of the electric heater, the outlet of the electric heater is connected to the inlet of the carbon monoxide removal device, and the outlet of the carbon monoxide removal device is connected to the inlet of the nitrogen oxide removal device.

[0010] Preferably, the electric heater, carbon monoxide removal device, and nitrogen oxide removal device are integrated together to form an integrated device.

[0011] Preferably, the device further includes a fan and an exhaust stack. The fan is disposed between the nitrogen oxide removal device and the exhaust stack. The fan inlet is connected to the nitrogen oxide removal device, and the fan outlet is connected to the exhaust stack.

[0012] Preferably, the washing tower is provided with a primary mercury removal layer, a secondary mercury removal layer and a tertiary mercury removal layer from bottom to top, the air inlet of the washing tower is located below the primary mercury removal layer and the air outlet of the washing tower is located above the tertiary mercury removal layer;

[0013] The scrubbing tower is also equipped with a heavy metal oxidant inlet, which is located below the air inlet of the scrubbing tower.

[0014] Preferably, the desulfurization tower is provided with a primary deacidification layer, a secondary deacidification layer and a tertiary deacidification layer from bottom to top, the desulfurization tower inlet is located below the primary deacidification layer and the desulfurization tower outlet is located above the tertiary deacidification layer.

[0015] The desulfurization tower is also equipped with an alkaline solution inlet, which is connected to the primary deacidification layer.

[0016] Preferably, a sampling point is provided between the dry filter and the activated carbon device.

[0017] Preferably, a urea injection mixing pipe is provided between the carbon monoxide removal device and the nitrogen oxide removal device, with the inlet of the urea injection mixing pipe connected to the carbon monoxide removal device and the outlet of the urea injection mixing pipe connected to the nitrogen oxide removal device.

[0018] Preferably, the urea injection mixing pipe is connected in sequence to the urea injection cabinet, filter, compressed air storage tank and air compressor via the urea injection gun pipe.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. This utility model removes heavy metals such as mercury from exhaust gas through a scrubbing tower and activated carbon device, which helps to solve the problem of excessive mercury content in exhaust gas emitted into the atmosphere.

[0021] 2. This utility model uses filtration equipment such as bag filters and dry filters to intercept particulate matter in exhaust gas;

[0022] 3. This utility model removes acidic substances, nitrogen oxides, carbon monoxide and other pollutants from the exhaust gas through a desulfurization tower, a carbon monoxide removal device and a nitrogen oxide treatment device, and finally achieves emission standards. Attached Figure Description

[0023] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the structure of the exhaust gas treatment device that is the main feature of this utility model.

[0025] In the picture:

[0026] Baghouse dust collector 1, Fan 9

[0027] Scrubber 2, Exhaust pipe 10

[0028] Desulfurization tower 3, urea injection mixing pipe 11

[0029] Dry filter 4, urea spray gun pipe 12

[0030] Activated carbon device 5, filter 13

[0031] 6 electric heaters, 14 compressed air storage tanks

[0032] Carbon monoxide removal device 7; Air compressor 15

[0033] Nitrogen oxide removal device 8 Detailed Implementation

[0034] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0035] like Figure 1As shown, a waste pyrolysis tail gas treatment device provided by this utility model includes a bag filter 1, a scrubbing tower 2, a desulfurization tower 3, a dry filter 4, an activated carbon device 5, an electric heater 6, a carbon monoxide removal device 7, a nitrogen oxide removal device 8, a fan 9, and an exhaust stack 10. Waste pyrolysis tail gas enters bag filter 1 through the inlet. The outlet of bag filter 1 is connected to the inlet of scrubbing tower 2. The outlet of scrubbing tower 2 is connected to the inlet of desulfurization tower 3. The outlet of desulfurization tower 3 is connected to the inlet of dry filter 4. The outlet of dry filter 4 is connected to the inlet of activated carbon device 5. The outlet of activated carbon device 5 is connected to the inlet of electric heater 6. The outlet of electric heater 6 is connected to the inlet of carbon monoxide removal device 7. The outlet of carbon monoxide removal device 7 is connected to the inlet of nitrogen oxide removal device 8. Fan 9 is installed between nitrogen oxide removal device 8 and exhaust stack 10. The inlet of fan 9 is connected to nitrogen oxide removal device 8, and the outlet of fan 9 is connected to exhaust stack 10. After collection and treatment, the tail gas meets the national emission standards and is discharged from exhaust stack 10.

[0036] This invention removes heavy metals such as mercury from the exhaust gas through a scrubbing tower 2 and an activated carbon device 5, solving the problem of excessive mercury content in exhaust gas emitted into the atmosphere; it also uses a bag filter 1, a dry filter 144, and other filtration equipment to trap particulate matter in the exhaust gas; and it removes acidic substances, nitrogen oxides, carbon monoxide, and other pollutants from the exhaust gas through a desulfurization tower 3, a carbon monoxide removal device 7, and a nitrogen oxide treatment device, ultimately achieving emission standards.

[0037] Specifically, the electric heater 6, the carbon monoxide removal device 7, and the nitrogen oxide removal device 8 are integrated into a single unit. The electric heater 6 can heat the gas to a temperature of up to 400 degrees Celsius, providing a suitable temperature for the chemical reaction to occur in the carbon monoxide removal device 7 and the nitrogen oxide removal device 8. A urea injection mixing pipe 11 is installed between the carbon monoxide removal device 7 and the nitrogen oxide removal device 8. The inlet of the urea injection mixing pipe 11 is connected to the carbon monoxide removal device 7, and the outlet of the urea injection mixing pipe 11 is connected to the nitrogen oxide removal device 8. The urea injection mixing pipe 11 is connected in sequence to the urea injection cabinet 13, the filter 14, the compressed air storage tank 15, and the air compressor 16 via the urea spray gun pipe 12. The air compressor 16, the compressed air storage tank 15, the filter 14, and the urea injection cabinet 13 provide the equipment foundation for urea injection.

[0038] Specifically, the scrubbing tower 2 is equipped with a primary mercury removal layer, a secondary mercury removal layer, and a tertiary mercury removal layer arranged sequentially from bottom to top. The air inlet of the scrubbing tower 2 is located below the primary mercury removal layer, and the air outlet of the scrubbing tower 2 is located above the tertiary mercury removal layer. The scrubbing tower 2 is also equipped with a heavy metal oxidant inlet, which is located below the air inlet of the scrubbing tower 2. The heavy metal oxidant can be in gaseous form. After entering the scrubbing tower 2, the gaseous heavy metal oxidant flows from bottom to top into the air inlet of the scrubbing tower 2, the primary mercury removal layer, the secondary mercury removal layer, and the tertiary mercury removal layer, which can better carry out the mercury removal reaction and remove heavy metal mercury from the exhaust gas. The mercury removal rate can reach 99% or higher.

[0039] Specifically, the desulfurization tower 3 is equipped with a primary deacidification layer, a secondary deacidification layer, and a tertiary deacidification layer arranged sequentially from bottom to top. The air inlet of the desulfurization tower 3 is located below the primary deacidification layer, and the air outlet of the desulfurization tower 3 is located above the tertiary deacidification layer. The desulfurization tower 3 also has an alkaline solution inlet, which is connected to the primary deacidification layer. The alkaline solution inlet is located above the air inlet of the desulfurization tower 3. After the exhaust gas enters the desulfurization tower 3, it passes through the alkaline solution, which neutralizes the acidic substances in the exhaust gas, thus removing them.

[0040] Specifically, a sampling point is provided between the dry filter 4 and the activated carbon device 5. Exhaust gas can be collected at this sampling point to detect the content of various harmful substances in the exhaust gas.

[0041] Dioxins in municipal solid waste incineration fly ash are removed using pyrolysis technology. The exhaust gas produced during pyrolysis reaches a temperature of 100–150°C. After filtration by baghouse dust collector 1, most particulate matter in the exhaust gas is retained. The exhaust gas, after filtration by baghouse dust collector 1, undergoes a mercury removal reaction in scrubbing tower 2 (using heavy metal mercury oxidants, etc.) to remove heavy metal mercury, achieving a removal rate of 99% or higher. After removing heavy metal mercury, the exhaust gas enters desulfurization tower 3 to remove acidic substances. After scrubbing in scrubbing tower 2 and desulfurization tower 3, the exhaust gas temperature is reduced to 20–30°C, and a small amount of... Moisture in the exhaust gas is removed by the dry filter 4, along with a small amount of particulate matter that was not removed in the bag filter 1. After passing through the dry filter 4, the exhaust gas then passes through the activated carbon device 5 (filled with proprietary activated carbon) to further remove heavy metals such as mercury. Mercury and its compounds (calculated as Hg) are ≤0.05mg / m3. After passing through the activated carbon device 5, the exhaust gas then passes through an integrated device (electric heater 6, carbon monoxide removal device 7, urea injection mixing pipe 11, and nitrogen oxide removal device 8) to remove pollutants such as nitrogen oxides and carbon monoxide from the exhaust gas, finally achieving emission standards.

[0042] The dioxins in fly ash are removed by pyrolysis technology. The exhaust gas treatment device of this invention removes other complex components from the exhaust gas. The exhaust gas produced during the pyrolysis process is relatively complex, mainly containing pollutants such as sulfides, nitrogen oxides, particulate matter, acidic substances, heavy metal mercury and other heavy metals. After being collected and treated by the exhaust gas treatment device of this invention, the exhaust gas is discharged after meeting the national emission standards.

[0043] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0044] The specific embodiments of this utility model have been described above. It should be understood that this utility model is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the substantive content of this utility model. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A waste pyrolysis off-gas treatment apparatus, characterized by, Includes bag filter (1), scrubbing tower (2), desulfurization tower (3), dry filter (4), and activated carbon device (5); The waste pyrolysis tail gas enters the bag filter (1) through the inlet of the bag filter (1). The outlet of the bag filter (1) is connected to the inlet of the scrubbing tower (2). The outlet of the scrubbing tower (2) is connected to the inlet of the desulfurization tower (3). The outlet of the desulfurization tower (3) is connected to the inlet of the dry filter (4). The outlet of the dry filter (4) is connected to the inlet of the activated carbon device (5).

2. The waste pyrolysis off-gas treatment device of claim 1, wherein, It also includes an electric heater (6), a carbon monoxide removal device (7), and a nitrogen oxide removal device (8); The outlet of the activated carbon device (5) is connected to the inlet of the electric heater (6), the outlet of the electric heater (6) is connected to the inlet of the carbon monoxide removal device (7), and the outlet of the carbon monoxide removal device (7) is connected to the inlet of the nitrogen oxide removal device (8).

3. The waste pyrolysis off-gas treatment device of claim 2, wherein, The electric heater (6), carbon monoxide removal device (7), and nitrogen oxide removal device (8) are integrated together to form an integrated device.

4. The waste pyrolysis off-gas treatment device of claim 2, wherein, It also includes a fan (9) and an exhaust stack (10). The fan (9) is located between the nitrogen oxide removal device (8) and the exhaust stack (10). The air inlet of the fan (9) is connected to the nitrogen oxide removal device (8), and the air outlet of the fan (9) is connected to the exhaust stack (10).

5. The waste pyrolysis off-gas treatment device of claim 1, wherein, The washing tower (2) is provided with a first-stage mercury removal layer, a second-stage mercury removal layer and a third-stage mercury removal layer from bottom to top. The air inlet of the washing tower (2) is located below the first-stage mercury removal layer and the air outlet of the washing tower (2) is located above the third-stage mercury removal layer. The scrubbing tower (2) is also provided with a heavy metal oxidant inlet, which is located below the air inlet of the scrubbing tower (2).

6. The waste pyrolysis off-gas treatment device of claim 1, wherein, The desulfurization tower (3) is provided with a first-stage desulfurization layer, a second-stage desulfurization layer and a third-stage desulfurization layer from bottom to top. The air inlet of the desulfurization tower (3) is located below the first-stage desulfurization layer and the air outlet of the desulfurization tower (3) is located above the third-stage desulfurization layer. The desulfurization tower (3) is also provided with an alkaline solution inlet, which is connected to the primary deacidification layer.

7. The waste pyrolysis off-gas treatment device of claim 1, wherein, A sampling point is provided between the dry filter (4) and the activated carbon device (5).

8. The waste pyrolysis off-gas treatment device of claim 2, wherein, A urea injection mixing pipe (11) is provided between the carbon monoxide removal device (7) and the nitrogen oxide removal device (8). The inlet of the urea injection mixing pipe (11) is connected to the carbon monoxide removal device (7), and the outlet of the urea injection mixing pipe (11) is connected to the nitrogen oxide removal device (8).

9. The waste pyrolysis off-gas treatment device of claim 8, wherein, The urea injection mixing pipe (11) is connected in sequence to the urea injection cabinet (13), filter (14), compressed air storage tank (15) and air compressor (16) through the urea spray gun pipe (12).

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