Low-nox desulfurization waste liquid incinerator for improving sulfur conversion rate

Abstract

The utility model belongs to incinerator technical field, concretely relates to a low NOx desulfurization waste liquid incinerator of improving sulfur conversion rate, including the incinerator body of whole horizontal structure, the incinerator body is successively composed of furnace head end wall, cylinder hearth and furnace tail end wall, the cylinder hearth of incinerator body includes first dam and second dam, and separates into combustion chamber, oxygen -enriched combustion zone and intensifies the three reaction areas of supplementary combustion area in hearth, the furnace head end wall on the front part of incinerator body is provided with the uniformly distributed waste liquid lance, gas liquid sulfur dual fuel burner and air supply pipe group. The utility model discloses through the setting of gas liquid sulfur dual fuel burner, the synergistic effect with waste liquid lance and air supply pipe, the air quantity required for the medium reaction of furnace is reasonably controlled, ensures that the combustion process is more sufficient, stable, improves sulfur conversion rate, reduces S pollution emission, also significantly reduces the emission of NOx, realizes the dual goal of environmental protection and high efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of incinerator technology, specifically relating to a low-NOx desulfurization waste liquid incinerator that improves sulfur conversion rate. Background Technology

[0002] Desulfurization wastewater, generated in the desulfurization process of the coking industry, contains various harmful components such as ammonium thiocyanate (NH4SCN), ammonium thiosulfate (NH4)2S2O3, ammonium sulfate (NH4)2SO4, ammonium sulfite (NH4)2SO3, elemental sulfur (Sx), and water (H2O). Pretreatment, incineration, and decomposition of this wastewater to produce sulfuric acid is a newly developed environmentally friendly technology and process. Direct discharge of desulfurization wastewater not only causes serious environmental pollution but also wastes resources. Traditional desulfurization wastewater incinerators suffer from low sulfur conversion rates, resulting in insufficient conversion of sulfur into usable sulfides for recovery and utilization, leading to sulfur pollution emissions and the production of high concentrations of nitrogen oxides (NOx), further exacerbating air pollution. To address these issues, improve sulfur conversion rates, and reduce NOx emissions, the development of a new type of low-NOx desulfurization wastewater incinerator is essential. Utility Model Content

[0003] In response to the shortcomings and deficiencies of existing technologies, this invention achieves a significant increase in sulfur conversion rate and an effective reduction in NOx emissions by optimizing the furnace structure, improving the air supply distribution method of the combustion system, and enhancing the mixing of furnace gas disturbance.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A low-NOx desulfurization waste liquid incinerator for improving sulfur conversion rate includes an overall horizontal incinerator body. The incinerator body is composed of a furnace head end wall, a cylindrical furnace chamber, and a furnace tail end wall. The cylindrical furnace chamber of the incinerator body includes a first baffle wall and a second baffle wall, dividing the furnace chamber into three reaction zones: a combustion chamber, an oxygen supplementation combustion zone, and an enhanced combustion zone. The furnace head end wall at the front of the incinerator body is equipped with evenly distributed waste liquid spray guns, a gas-liquid-sulfur dual-fuel burner, and an air supply pipe assembly. The gas-liquid-sulfur dual-fuel burner is horizontally installed inside the furnace head end wall, and multiple gas spray guns are also installed at the central air duct located around the middle of the gas-liquid-sulfur dual-fuel burner. The waste liquid spray guns are horizontally installed inside the furnace head end wall and arranged around the upper periphery of the gas-liquid-sulfur dual-fuel burner.

[0005] The air supply duct assembly supplies air for combustion and decomposition to the gas-liquid-sulfur dual-fuel burner and the waste liquid spray gun. The air supply duct assembly is divided into four primary air ducts and one secondary air duct. The primary air ducts send air into the air inlets of the waste liquid spray gun and the gas-liquid-sulfur dual-fuel burner, and the amount of air supplied is regulated by the air regulating butterfly valve. The secondary air ducts send air to the first baffle wall, and the air is distributed to several secondary air spray pipes through the header on the outer wall of the cylindrical furnace. The secondary air spray pipes pass through the inside of the first baffle wall and spray out into the furnace gas at the bottom.

[0006] The waste liquid spray gun atomizes and sprays the desulfurization waste liquid into the air flow sent through the air regulating butterfly valve. The waste liquid mixes with the air and enters the combustion chamber to form a liquid mist zone, where it undergoes a decomposition reaction, converting the element S in the waste liquid into SO2.

[0007] The gas-liquid sulfur dual-fuel burner is equipped with a gas inlet at the top, which distributes the gas into multiple gas spray guns arranged around the central air duct. The central air duct is equipped with liquid sulfur spray guns.

[0008] The liquid sulfur spray gun is equipped with a liquid sulfur inlet at its inlet end, and a steam insulation jacket is also provided outside the liquid sulfur spray gun.

[0009] The gas injection gun and liquid sulfur injection gun inject gas and liquid sulfur into the airflow supplied by the air regulating butterfly valve through the gas inlet and liquid sulfur inlet respectively. After mixing, they are injected into the flame zone in the lower part of the combustion chamber for combustion reaction. The element S in the liquid sulfur is burned to form SO2.

[0010] The reaction products of the liquid mist zone and the flame zone mix in the rear of the combustion chamber to form furnace gas, which contains a large amount of SO2.

[0011] The steam insulation jacket is equipped with a metal expansion joint.

[0012] The first baffle wall has a first baffle wall channel at its lower part, and the flow area of ​​the first baffle wall channel is smaller than the cross-sectional area of ​​the furnace.

[0013] The second retaining wall has four narrow second retaining wall channels around its outer edge, and the sum of the areas of the four second retaining wall channels is less than the cross-sectional area of ​​the furnace.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention, through the installation of a dual-fuel burner for gas and liquid sulfur, can flexibly adjust the injection ratio of gas and liquid sulfur according to actual needs. Working in conjunction with the waste liquid spray gun and air supply pipe, it rationally controls the amount of air required for the reaction of the fuel medium, ensuring a more complete and stable combustion process, thereby effectively improving sulfur conversion efficiency. Simultaneously, through the optimization of the baffle structure inside the incinerator, a unique channel design allows the furnace gas to undergo a complex flow process of contraction, acceleration, and expansion as it passes through. This change in flow state greatly enhances the disturbance and mixing of various components in the furnace gas, providing more contact and reaction opportunities for incompletely reacted components. Thus, while improving sulfur conversion rate and reducing sulfur pollution emissions, it also significantly reduces NOx emissions, achieving the dual goals of environmental protection and high efficiency. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Figure 2 This is a schematic diagram of the end of the furnace head of this utility model.

[0017] Figure 3 This is a schematic diagram of the first retaining wall structure of this utility model.

[0018] Figure 4 This is a schematic diagram of the second retaining wall structure of this utility model.

[0019] Figure 5 This is a schematic diagram of the structure of the gas-liquid-sulfur dual-fuel burner of this utility model.

[0020] In the diagram: 1. Furnace head end wall, 2. Cylindrical furnace, 3. Combustion chamber, 4. First baffle wall, 5. Header, 6. Secondary air nozzle, 7. Oxygen supplementation combustion zone, 8. Second baffle wall, 9. Enhanced combustion zone, 10. Furnace tail end wall, 11. Furnace gas outlet, 12. Air inlet, 13. Air supply duct assembly, 14. Secondary air duct, 15. Primary air duct, 16. Air regulating butterfly valve, 17. Waste liquid spray gun, 18. Gas-liquid sulfur dual-fuel burner, 19. Waste liquid inlet, 20. Liquid mist zone, 21. Gas inlet, 22. Liquid sulfur inlet, 23. Liquid sulfur spray gun, 24. Gas spray gun, 25. Steam insulation jacket, 26. Metal expansion joint, 27. Flame zone, 28. Central air duct, 29. Furnace gas, 30. First baffle wall passage, 31. Second baffle wall passage. Detailed Implementation

[0021] The present invention will be described in conjunction with the accompanying drawings.

[0022] like Figure 1-5The diagram illustrates a low-NOx desulfurization waste liquid incinerator for improving sulfur conversion rate, comprising an overall horizontal incinerator body. The incinerator body is sequentially composed of a furnace head end wall 1, a cylindrical furnace chamber 2, and a furnace tail end wall 10. The cylindrical furnace chamber 2 includes a first baffle wall 4 and a second baffle wall 8, dividing the furnace chamber into three reaction zones: a combustion chamber 3, an oxygen-supplemented combustion zone 7, and an enhanced combustion zone 9. The furnace head end wall 1 at the front of the incinerator body is equipped with evenly distributed waste liquid spray guns 17, a gas-liquid-sulfur dual-fuel burner 18, and an air supply duct assembly 13. The gas-liquid-sulfur dual-fuel burner 18 is horizontally inserted into the furnace head end wall 1, and multiple gas spray guns 24 are also arranged around a central air duct 28 located in the middle of the gas-liquid-sulfur dual-fuel burner 18. The waste liquid spray guns 17 are horizontally inserted into the furnace head end wall 1 and arranged around the upper periphery of the gas-liquid-sulfur dual-fuel burner 18. The waste liquid spray gun 17 is located around the upper part of the dual-fuel burner 18. It uses internal or external mixing air atomization to atomize the waste liquid into extremely fine liquid mist, which is conducive to the timely vaporization and mixing of the waste liquid with air, and promotes the decomposition of the waste liquid. The air supply pipe group 13 supplies the air required for combustion and decomposition to the gas-liquid-sulfur dual-fuel burner and the waste liquid spray gun 17. The air supply pipe group 13 is divided into four primary air pipes 15 and one secondary air pipe 14. The primary air pipe 15 sends air into the air inlet 12 of the waste liquid spray gun 17 and the gas-liquid-sulfur dual-fuel burner 18 respectively. The amount of air supplied is adjusted by the air regulating butterfly valve 16. The secondary air pipe 14 is sent to the first baffle wall 4. The air is distributed to several secondary air nozzles 6 through the header 5 on the outer wall of the cylindrical furnace 2. The secondary air nozzles 6 pass through the interior of the first baffle wall 4 and spray out into the furnace gas 29 at the bottom.

[0023] The waste liquid spray gun 17 injects desulfurization waste liquid through its waste liquid inlet 19 at the end, and atomizes it into the airflow supplied via the air regulating butterfly valve 16. The waste liquid mixes with the air and enters the combustion chamber 3 to form a liquid mist zone 20, where a decomposition reaction occurs, converting element S in the waste liquid into SO2. The specific structure of the waste liquid spray gun 17 is the same as that in the applicant's authorized utility model patent application number 202320924077.2, entitled "A Waste Liquid Spray Gun for Combustion-Based Acid Production Process". By using the applicant's authorized waste liquid spray gun 17 in conjunction with the incinerator body and air supply pipe assembly 13 in this application, the atomization effect of the waste liquid can be significantly improved, allowing the waste liquid to mix fully with the air, thereby increasing the decomposition reaction rate and ensuring that element S in the waste liquid is fully converted into SO2, providing favorable conditions for subsequent conversion and acid production processes. At the same time, this combined use also helps to reduce NOx generation, achieving the goal of low NOx emissions and meeting environmental protection requirements.

[0024] The gas-liquid sulfur dual-fuel burner 18 has a gas inlet 21 at its top, which distributes the gas into multiple gas nozzles 24 arranged around a central air duct 28. A liquid sulfur nozzle 23 is installed in the central air duct 28. The liquid sulfur nozzle 23 has a liquid sulfur inlet 22 at its inlet end, and a steam insulation jacket 25 is provided outside the liquid sulfur nozzle 23 to keep the liquid sulfur within a suitable temperature range and maintain a low viscosity to achieve good atomization. The gas nozzles 24 and liquid sulfur nozzles 23 are connected through the gas inlet 21. The gas and liquid sulfur are injected together into the airflow supplied by the air regulating butterfly valve 16, and then mixed and injected into the flame zone 27 in the lower part of the combustion chamber 3 for combustion reaction. The element S in the liquid sulfur is burned to form SO2. The liquid sulfur spray gun 23 is directly installed on the central axis of the gas and liquid sulfur dual-fuel burner 18. It can replace the gas to supplement heat and maintain the furnace temperature. After the liquid sulfur is sprayed out from the spray gun 23, it is immediately in the surrounding airflow and enters the combustion state, shortening the reaction time and improving the combustion efficiency.

[0025] The reaction products of the liquid mist zone 20 and the flame zone 27 are mixed in the rear of the combustion chamber 3 to form furnace gas 29, which contains a large amount of SO2; the steam insulation jacket 25 is equipped with a metal expansion joint 26 to adapt to the uneven expansion of the inner and outer tubes during the alternation of hot and cold; the liquid sulfur spray gun 23 is equipped with a steam insulation jacket to keep the liquid sulfur in an appropriate temperature range and always at a low viscosity to obtain a better atomization effect; the steam insulation jacket 25 can heat and melt the residual sulfur deposited and solidified in the spray gun when the spray gun is restarted; the steam insulation jacket 25 is equipped with a metal expansion joint 26 to adapt to the uneven expansion of the inner and outer tubes during the alternation of hot and cold.

[0026] The first baffle wall 4 has a first baffle wall channel 30 at its lower part, and the flow area of ​​the first baffle wall channel 30 is smaller than the cross-sectional area of ​​the furnace. When the furnace gas 29 passes through, it undergoes a process of contraction, acceleration, and expansion, and is squeezed and disturbed, so that the furnace gas 29 can be uniformly mixed in terms of temperature and composition after entering the oxygen supplementation combustion zone 7. The second baffle wall 8 has four narrow second baffle wall channels 31 around its outer edge, and the sum of the areas of the four second baffle wall channels 31 is smaller than the cross-sectional area of ​​the furnace. When the furnace gas 29 passes through, it also undergoes a process of contraction, acceleration, and expansion, and is squeezed and disturbed, so that the furnace gas 29 can be uniformly mixed in terms of temperature and composition after entering the enhanced combustion zone 9.

[0027] In use, the dual-fuel burner injects air, fuel gas, and / or liquid sulfur into the flame zone of the combustion chamber, while the waste liquid spray gun injects air and waste liquid into the liquid mist zone of the combustion chamber. The fuel gas, liquid sulfur, and waste liquid undergo combustion or decomposition reactions in their respective zones. The primary air volume supplied to the combustion chamber 3 is less than the chemical equivalent air volume theoretically required for complete reaction of all media, resulting in an overall oxygen-deficient reaction state. The SO2-containing furnace gas in the combustion chamber 3 enters the oxygen-supplemented combustion zone 7 through the narrow channel 30 at the bottom of the first baffle wall 4. The flow area of ​​channel 30 is much smaller than the cross-sectional area of ​​the furnace. The reaction products of liquid mist zone 20 and flame zone 27 first flow downstream in layers. When flowing through channel 30 below the first baffle wall 4, they undergo a contraction, acceleration, and expansion process, being squeezed and disturbed, so that the furnace gas 29 after entering the oxygen-supplemented combustion zone 7 can be mixed evenly in terms of temperature and material composition. Then, the supplemented secondary air passes through the secondary air nozzles 6 arranged inside the first baffle wall and is sprayed into the furnace gas 29 at the bottom, which replenishes the insufficient oxygen supply in the combustion chamber 3 and promotes the continued reaction of the unburned and undecomposed media components. After the addition of secondary air, the combustion and decomposition reaction in the entire incinerator is generally in a state of oxygen excess, ensuring that the reaction of the media entering the furnace can be completed. After a certain distance of reaction and flow, the flow of furnace gas 29 will gradually become slower, and it will be difficult for the unreacted media components to mix with the increasingly thin oxygen. The overall reaction will gradually weaken. In order to further promote the reaction, a second baffle wall 8 is set at the end of this zone to stir and mix the furnace gas 29 again. The furnace gas reacts and flows within the oxygen-supplemented combustion zone 7, then gradually slows down, reducing the reaction rate. It then passes through several narrow channels 31 around the second baffle wall 8 before entering the enhanced combustion zone 9, where it is agitated and mixed again. Unreacted components in this zone react with oxygen again, ensuring complete reaction and the conversion of all sulfur (S) into SO2. Finally, the fully reacted furnace gas exits from the furnace gas outlet 11 at the furnace tail end wall 10 and is transferred to subsequent processing units for further processing of SO2 into concentrated sulfuric acid.

[0028] This incinerator design not only effectively improves the sulfur conversion rate, maximizing the conversion of sulfur (S) into SO2 and providing ample raw materials for subsequent concentrated sulfuric acid production, but also achieves low NOx emissions through its rational structural design. In the combustion chamber, the air supply to both the dual-fuel burner and the waste liquid spray gun is less than the stoichiometric amount of air theoretically required for complete reaction of all media. This oxygen-deficient reaction state reduces the chance of nitrogen reacting with oxygen, thereby inhibiting NOx formation. Simultaneously, the installation of the first and second baffle walls, along with the supplementation of secondary air, not only promotes the full reaction of the media but also ensures thorough agitation and mixing of the furnace gas within the incinerator, further improving the reaction efficiency of sulfur and reducing sulfur pollution emissions. Therefore, this low-NOx desulfurization waste liquid incinerator demonstrates excellent performance in both environmental protection and economic benefits.

[0029] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate, comprising an incinerator body with an integral horizontal structure; characterized in that: The incinerator body is composed of a furnace head end wall (1), a cylindrical furnace chamber (2), and a furnace tail end wall (10) in sequence. The cylindrical furnace chamber (2) of the incinerator body includes a first baffle wall (4) and a second baffle wall (8), which divides the furnace chamber into three reaction zones: a combustion chamber (3), an oxygen supplementation combustion zone (7), and an enhanced supplementation combustion zone (9). The furnace head end wall (1) at the front of the incinerator body is provided with evenly distributed waste liquid spray guns (17), a gas-liquid-sulfur dual-fuel burner (18), and an air supply pipe assembly (13). The gas-liquid-sulfur dual-fuel burner (18) is horizontally installed inside the furnace head end wall (1), and multiple gas spray guns (24) are also provided at the central air duct (28) set around the middle of the gas-liquid-sulfur dual-fuel burner (18). The waste liquid spray guns (17) are horizontally installed inside the furnace head end wall (1) and arranged on the upper periphery of the gas-liquid-sulfur dual-fuel burner (18).

2. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 1, characterized in that: The air supply pipe group (13) supplies air for combustion and decomposition to the gas-liquid-sulfur dual-fuel burner (18) and the waste liquid spray gun (17). The air supply pipe group (13) is divided into four primary air pipes (15) and one secondary air pipe (14). The primary air pipe (15) supplies air to the air inlet (12) of the waste liquid spray gun (17) and the gas-liquid-sulfur dual-fuel burner (18), and the amount of air supplied is adjusted by the air regulating butterfly valve (16). The secondary air pipe (14) is sent to the first baffle wall (4), and the air is distributed to several secondary air spray pipes (6) through the header (5) on the outer wall of the cylindrical furnace (2). The secondary air spray pipes (6) pass through the interior of the first baffle wall (4) and spray out into the furnace gas (29) at the bottom.

3. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 2, characterized in that: The waste liquid spray gun (17) atomizes and sprays the desulfurization waste liquid into the air flow sent through the air regulating butterfly valve (16). The waste liquid mixes with the air and enters the combustion chamber (3) to form a liquid mist zone (20) and undergoes a decomposition reaction, converting the element S in the waste liquid into SO2.

4. The low-NOx desulfurization waste liquid incinerator for improving sulfur conversion rate according to claim 2, characterized in that: The gas-liquid sulfur dual-fuel burner (18) is provided with a gas inlet (21) at the top, which distributes the gas into multiple gas spray guns (24) arranged around the central air duct (28), and a liquid sulfur spray gun (23) is installed in its central air duct (28).

5. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 4, characterized in that: The liquid sulfur spray gun (23) is provided with a liquid sulfur inlet (22) at the inlet end, and a steam insulation jacket (25) is also provided outside the liquid sulfur spray gun (23).

6. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 4, characterized in that: The gas spray gun (24) and liquid sulfur spray gun (23) inject gas and liquid sulfur into the air flow sent by the air regulating butterfly valve (16) through the gas inlet (21) and liquid sulfur inlet (22) respectively. After mixing, they are injected into the flame zone (27) in the lower part of the combustion chamber (3) for combustion reaction. The element S in the liquid sulfur is burned to form SO2.

7. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 5, characterized in that: The steam insulation jacket (25) is equipped with a metal expansion joint (26).

8. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 2, characterized in that: The first baffle (4) has a first baffle channel (30) at its lower part, and the flow area of ​​the first baffle channel (30) is smaller than the cross-sectional area of ​​the furnace.

9. The low-NOx desulfurization wastewater incinerator for improving sulfur conversion rate according to claim 1, characterized in that: The second baffle (8) has four narrow second baffle channels (31) around its outer edge, and the sum of the areas of the four second baffle channels (31) is less than the cross-sectional area of ​​the furnace.

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