Energy-saving activated carbon desulfurization and denitrification acid-making wastewater treatment system

Abstract

According to the energy-saving activated carbon desulfurization and denitrification acid-making wastewater treatment system disclosed by the utility model, the regeneration reactor is used for desorbing activated carbon adsorbed with SO2 gas from the activated carbon purification tower through hot air provided by the hot air furnace, and desorbed gas enters an acid-making purification section for cooling and dust removal and then enters a subsequent device for preparing sulfuric acid; the wastewater generated in the acid-making purification section is the acid-making wastewater. Acid-making wastewater is filtered by an acid liquor filter, the flow of supernate is adjusted by an acid liquor adjusting valve, then the supernate enters a vaporizer, high-temperature diffused flue gas discharged by a hot air diffusing valve is introduced into the lower part of the vaporizer by opening a hot smoke inlet gate valve, and the high-temperature diffused flue gas and the acid-making wastewater are mixed and evaporated; gas at the top of the vaporizer is mixed with sintering flue gas through a vaporized gas outlet valve for temperature equalization and then enters the activated carbon purification tower again, mixed gas is adsorbed by the activated carbon purification tower and then enters the regeneration reactor again for desorption, and desorbed gas enters an acid-making purification section for circulation, so that resource recycling of sulfur in the acid-making wastewater can be realized.

Description

Technical Field

[0001] The utility model belongs to the field of activated carbon desulfurization and denitration flue gas purification, relates to acid-making wastewater treatment technology, and specifically is an energy-saving activated carbon desulfurization and denitration acid-making wastewater treatment system. Background Art

[0002] my country's energy structure is mainly coal, and coal is widely used as a fuel in power generation, boiler heating, metallurgy and other technical fields. When coal is burned, the flue gas contains a large amount of pollutants such as SO2 and NOX. The emission has been high, causing serious pollution to the environment. The country has included air pollution control in the key prevention and control targets, especially sulfur and nitrogen oxide indicators are the top priority in air pollution control. Therefore, controlling the emission of pollutants such as SO2 and NOX and actively researching and developing flue gas desulfurization and denitrification technologies are important ways to control environmental pollution.

[0003] The activated carbon flue gas desulfurization and denitrification process is aimed at industrial flue gas, which can remove pollutants such as sulfur dioxide, nitrogen oxides, dust, dioxins, etc. at the same time, and can realize the resource utilization of sulfur dioxide. Based on the above advantages, this process has been fully promoted in my country and widely used in steel, coking and other industries.

[0004] The activated carbon desulfurization and denitrification process currently widely used in sintering flue gas purification uses the principle of porous adsorption characteristics of activated carbon to absorb and enrich SO2 gas in sintering flue gas for the production of concentrated sulfuric acid. In the production process of concentrated sulfuric acid using enriched high-temperature (about 360°C) and high-dust SO2 gas, acidic wastewater is generated during the cooling and washing of the acid purification section. The acidic wastewater not only has high content of ammonia nitrogen, sulfur, and carbon powder, but also contains harmful substances that inhibit bacteria. It is the only secondary pollution in the activated carbon desulfurization and denitrification process.

[0005] Chinese patent CN214735046U discloses an acid-making wastewater treatment and recovery system applied to an activated carbon dry flue gas treatment device, which mainly includes a regulating tank, a reaction tank, and a reuse water tank. The regulating tank is connected to a wastewater inlet pipe and is used to collect and store acid-containing and ammonia-containing wastewater. The regulating tank is connected to the reaction tank through a pipeline. The reaction tank is connected to the reuse water tank, a lime powder automatic feeder, a deammonification agent dosing device, a blower, and an induced draft fan through pipelines. This method can realize the reuse of part of the wastewater and waste ammonia, but most of the sulfur in the acid-making waste liquid is neutralized and turned into solid waste, and the resource utilization of sulfur is not realized.

[0006] Chinese patent application CN116835827A discloses a method for zero-discharge treatment of sintering acid wastewater, including the following steps: chemical pretreatment, used to pretreat the wastewater to reduce the ions in the sintering acid wastewater; deammoniation treatment, used to remove ammonia nitrogen in the wastewater; evaporation and crystallization treatment, the wastewater is subjected to membrane separation treatment to obtain industrial new water and concentrated water, and the concentrated water is evaporated and crystallized to obtain industrial salt. The above process basically realizes the reuse of acid wastewater, but its process flow is long and the investment is high. It also involves an evaporation process, which requires the introduction of an external heat source, has high energy consumption, and has a high operating cost. Utility Model Content

[0007] In order to overcome the deficiencies in the prior art, the utility model provides an energy-saving activated carbon desulfurization and denitrification acid-making wastewater treatment system, which can realize the resource recycling of sulfur in the acid-making wastewater and reduce the operating cost.

[0008] The technical solution adopted by the utility model to solve its technical problems is:

[0009] An energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system, comprising at least:

[0010] Hot air furnace, used to provide high-temperature hot air;

[0011] A regeneration reactor is connected to the hot blast furnace and the activated carbon purification tower, and is used to desorb the activated carbon adsorbed with SO2 gas from the activated carbon purification tower through hot blast provided by the hot blast furnace;

[0012] The acid purification section is connected to the regeneration reactor and is used to receive and process the desorbed gas from the regeneration reactor;

[0013] Acid filter, connected to the acid purification section, used to filter the acid wastewater generated in the acid purification section;

[0014] The vaporizer is connected to the acid filter and is used to receive the supernatant produced by the acid filter in filtering the acid-making wastewater; the vaporizer is connected to the hot air discharging pipe of the hot blast furnace through the hot smoke inlet gate valve, and is used to introduce the high-temperature discharging flue gas discharged by the hot air discharging valve to mix with the supernatant to evaporate and precipitate SO2 gas; the vaporizer is also connected to the sintering flue through the vaporizer outlet regulating valve, and is used to mix the precipitated SO2 gas with the sintering flue gas to evenly mix the temperature; the sintering flue is connected to the activated carbon purification tower, and is used to allow the mixed gas to pass into the activated carbon purification tower for adsorption, and then re-enter the regeneration reactor for desorption cycle.

[0015] Furthermore, it also includes:

[0016] A filter press connected to the acid filter is used to further separate the solid and liquid from the filter residue produced by the acid filter;

[0017] The liquid collecting tank is connected to the filter press and the vaporizer, and is used to receive and store the acidic wastewater discharged from the filter press and the wastewater containing solid impurities discharged from the vaporizer.

[0018] Furthermore, the liquid collecting tank is also connected to the acid purification section, and an acid circulation valve and an acid collection valve are provided on the connecting pipe between the two; an acid circulation pump is provided in the liquid collecting tank, which is used to mix the solid impurities in the liquid collecting tank with the acidic wastewater to form a suspension and pump it into the acid purification section, so that the suspension enters the acid filter together with the acid wastewater in the acid purification section.

[0019] Furthermore, it also includes:

[0020] The neutralization tank is connected to the collecting tank and is used for emergency purposes to neutralize the pH value of the wastewater in the collecting tank and then pump it to the sintering batching water pool.

[0021] Furthermore, it also includes:

[0022] The heat circulation fan is connected between the hot air dispersing duct of the regeneration reactor and the hot air stove, and is used for hot air circulation between the regeneration reactor and the hot air stove.

[0023] Furthermore, an acid liquid regulating valve is provided on the connecting pipe between the vaporizer and the acid liquid filter for regulating the flow rate of the acid liquid supernatant entering the vaporizer.

[0024] Furthermore, a condensate drain valve is provided on the connecting pipe between the liquid collecting tank and the vaporizer to control the discharge of waste water containing solid impurities in the vaporizer.

[0025] Furthermore, the vaporizer is a temperature-resistant and corrosion-resistant vaporizer.

[0026] The beneficial effects of the utility model include:

[0027] The utility model introduces a vaporizer, and introduces the high-temperature flue gas with a temperature of up to 300-330°C discharged from the hot air release valve of the hot blast furnace into the vaporizer, and the acid-making supernatant liquid filtered by the acid liquid filter is sprayed into the middle of the vaporizer, the high-temperature flue gas and the acid-making supernatant liquid are mixed and evaporated through the vaporizer to precipitate SO2 gas, the vaporizer outlet is connected to the original sintering flue, the precipitated SO2 gas is mixed with a large amount of sintering flue gas and the temperature is evenly adjusted to 120-140°C, and re-enters the activated carbon purification tower, and after adsorption by the activated carbon purification tower, enters the regeneration reactor again for desorption, and the analyzed gas enters the acid-making purification section; based on this, the high-temperature flue gas emitted from the hot blast furnace in the original activated carbon desulfurization and denitrification process vaporizes the waste acid liquid and then introduces it into the desulfurization and denitrification system for circulation, so that the "sulfur" in the waste acid liquid is fully resourced, the generated waste liquid is eliminated, and the high-temperature hot flue gas emitted from the hot blast furnace in the original activated carbon desulfurization and denitrification process can be fully utilized, which is energy-saving and environmentally friendly.

[0028] The utility model provides an energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system, which solves the shortcomings and problems of high energy consumption, high investment and difficulty in recycling involved in the recovery and treatment process of acid production waste liquid, so that the "sulfur" in the waste acid liquid can be fully utilized as a resource; the high-temperature emitted flue gas used for analyzing SO2 gas is recycled and utilized, realizing the coordinated control of the generation of hot flue gas and waste acid liquid; the system construction cost is low, and the hot air furnace in the original activated carbon desulfurization and denitrification process is used as the heat source, without the need to use an external heat source, thereby reducing energy consumption and lowering operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of an energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system of the utility model.

[0030] In the figure: 1. hot air furnace; 2. regeneration reactor; 3. heat circulation fan; 4. acid purification section; 5. acid filter; 6. filter press; 7. liquid collecting tank; 8. neutralization tank; 9. hot air release valve; 10. acid circulation valve; 11. acid collection valve; 12. acid regulating valve; 13. vaporizer outlet regulating valve; 14. vaporizer; 15. condensate drain valve; 16. hot smoke inlet gate valve; 17. activated carbon purification tower; 18. acid circulation pump. DETAILED DESCRIPTION

[0031] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0033] Example 1

[0034] An energy-saving activated carbon desulfurization and denitrification acid wastewater treatment system, such as Figure 1 As shown, it includes a hot air furnace 1, a regeneration reactor 2, a heat circulation fan 3, an acid purification section 4, an acid liquid filter 5, a filter press 6, a liquid collecting tank 7, a neutralization tank 8, a hot air release valve 9, an acid liquid circulation valve 10, an acid liquid collecting valve 11, an acid liquid regulating valve 12, a vaporizer outlet regulating valve 13, a vaporizer 14, a condensate discharge valve 15, a hot smoke inlet gate valve 16, an activated carbon purification tower 17, and an acid liquid circulation pump 18.

[0035] The connection relationship between the above-mentioned equipment / accessories is as follows: the regeneration reactor 2 is connected to the hot blast furnace 1 and the activated carbon purification tower 17, the acid purification section 4 is connected to the regeneration reactor 2, the acid liquid filter 5 is connected to the acid purification section 4, the vaporizer 14 is connected to the acid liquid filter 5 through the acid liquid regulating valve 12, the vaporizer 14 is connected to the hot air dissipation pipeline of the hot blast furnace 1 through the hot smoke inlet plug valve 16, and the hot air dissipation pipeline is provided with a hot air dissipation valve 9; the top outlet of the vaporizer 14 is connected to the sintering flue through the vaporizer outlet regulating valve 13, and the sintering flue is connected to the activated carbon purification tower 17; the filter press 6 is connected to the acid liquid filter 5, the collecting tank 7 is connected to the filter press 6 and the vaporizer 14, and the collecting tank 7 is also connected to the acid purification section 4, and the connecting pipeline between the two is provided with an acid liquid circulation valve 10 and an acid liquid collection valve 11; the collecting tank 7 is provided with an acid liquid circulation pump 18. The neutralization tank 8 is connected to the liquid collecting tank 7 , the heat circulation fan 3 is connected between the hot air dissipation pipeline of the regeneration reactor 2 and the hot air furnace 1 , and a condensate discharge valve 15 is provided on the connecting pipeline between the liquid collecting tank 7 and the vaporizer 14 .

[0036] Based on the above structural setting, the working process of this system is as follows: the regeneration reactor 2 desorbs the activated carbon adsorbed with SO2 gas from the activated carbon purification tower 17 through the hot air provided by the hot air furnace 1, and the desorbed analysis gas enters the acid purification section 4 for cooling and dust removal, and then enters the subsequent device to produce sulfuric acid. The wastewater generated by the acid purification section 4 is acid wastewater.

[0037] The acid-making wastewater is filtered through the acid liquid filter 5, and the supernatant enters the vaporizer 14 after the flow rate is adjusted by the acid liquid regulating valve 12. The hot smoke inlet gate valve 16 is opened at the lower part of the vaporizer 14 to introduce the high-temperature emission flue gas discharged by the hot air emission valve 9. After the high-temperature emission flue gas is mixed with the acid-making wastewater and evaporated, the gas at the top of the vaporizer 14 is mixed with the sintering flue gas through the vaporization gas outlet valve 13 and the temperature is evenly adjusted to 120-140°C, and then re-enters the activated carbon purification tower 17. After the mixed gas is adsorbed by the activated carbon purification tower 17, it enters the regeneration reactor 2 again for desorption, and the analyzed gas enters the acid-making purification section for circulation.

[0038] Preferably, the vaporizer 14 is a temperature-resistant and corrosion-resistant vaporizer, and the material can be stainless steel, carbon steel, etc. Its main function is to reversely mix and evaporate the emitted flue gas with a temperature of up to 300-330°C with the acid-making wastewater, and analyze the acid gas in the acid-making wastewater to achieve the purpose of wastewater treatment.

[0039] The hot smoke inlet gate valve 16 is mainly used to introduce the high-temperature hot smoke discharged during the operation of the hot blast furnace 1 to the vaporizer 14 in order to maintain normal combustion.

[0040] The acid liquid regulating valve 12 is used to adjust the flow rate of the supernatant liquid from the acid liquid filter 5 entering the vaporizer 14 to meet the needs of changes in working conditions.

[0041] The function of the vaporized gas outlet valve 13 is to discharge the SO2 gas analyzed from the acid-making wastewater into the activated carbon purification tower 17 to realize the resource utilization of the "sulfur" after the acid-making wastewater treatment.

[0042] The function of the condensate discharge valve 15 is to regularly discharge the carbon powder, salts and mechanical impurities in the mixed and evaporated acid-making wastewater from the vaporizer 14 to ensure the stable operation of the vaporizer 14 .

[0043] The function of the acid circulation pump 18 is to mix the solid impurities in the liquid collecting tank 7 with the acidic water to form a suspension, and pump the suspension into the acid purification section 4, so that the suspension and the acid wastewater of the acid purification section 4 enter the acid filter 5 for filtration, and the solid impurities are discharged from the system after filtration and cake pressing by the filter press 6.

[0044] In this system, the neutralization tank 8 is used as an emergency device. When the suspended liquid in the liquid collecting tank 7 cannot be pumped into the acid purification section 4, the liquid in the liquid collecting tank 7 enters the neutralization tank 8 for pH value neutralization and is then pumped to the sintering batching water pool.

[0045] In this system, the vaporizer 14 is a key equipment, which solves the problem of recycling the acid-making wastewater, and cleverly uses the high-temperature flue gas discharged from the hot blast furnace 1 in the regeneration heating system of the desulfurization and denitration device as the heat source of the vaporizer 14 to vaporize the acid-making wastewater. The vaporized gas enters the desulfurization and denitration device, that is, the activated carbon purification tower 17, and the SO2 gas adsorbed, regenerated and desorbed by the activated carbon enters the acid-making device again to produce sulfuric acid. On the one hand, the system fully recycles the "sulfur" in the waste acid liquid, and on the other hand, no external heat source is added in the process of treating the acid-making wastewater, which reduces energy consumption and operating costs, solves the problem of difficult treatment and recycling of acid-making wastewater, and achieves the dual benefits of energy saving and resource recovery, with good economic value and social value.

[0046] In summary, the utility model provides an energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system, which can realize the resource recovery of acid production wastewater, has low transformation cost, does not add external heat source, and has low operating cost. It is an energy-saving acid production wastewater treatment solution.

[0047] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. An energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system, characterized in that: At least: A hot air furnace (1), used for providing high-temperature hot air; A regeneration reactor (2) is connected to the hot blast furnace (1) and the activated carbon purification tower (17) and is used to desorb the activated carbon adsorbed with SO2 gas from the activated carbon purification tower (17) by means of hot blast provided by the hot blast furnace (1); The acid purification section (4) is connected to the regeneration reactor (2) and is used to receive and process the desorbed gas from the regeneration reactor (2); An acid filter (5) connected to the acid purification section (4) and used to filter the acid wastewater generated by the acid purification section (4); The vaporizer (14) is connected to the acid filter (5) and is used to receive the supernatant produced by the acid filter (5) filtering the acid-making wastewater; the vaporizer (14) is connected to the hot air dispersing pipe of the hot blast furnace (1) through the hot smoke inlet plug valve (16) and is used to introduce the high-temperature dispersing flue gas discharged by the hot air dispersing valve (9) to mix with the supernatant to evaporate and precipitate SO2 gas; the vaporizer (14) is also connected to the sintering flue through the vaporizer outlet regulating valve (13) to mix the precipitated SO2 gas with the sintering flue gas to evenly mix the temperature; the sintering flue is connected to the activated carbon purification tower (17) to allow the mixed gas to pass into the activated carbon purification tower (17) for adsorption and then re-enter the regeneration reactor (2) for desorption cycle.

2. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 1 is characterized in that: Also includes: A filter press (6) connected to the acid filter (5) and used for further solid-liquid separation of filter residue produced by the acid filter (5); The liquid collecting tank (7) is connected to the filter press (6) and the vaporizer (14) and is used to receive and store the acidic wastewater discharged from the filter press (6) and the wastewater containing solid impurities discharged from the vaporizer (14).

3. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 2 is characterized in that: The liquid collecting tank (7) is also connected to the acid purification section (4), and an acid circulation valve (10) and an acid collection valve (11) are provided on the connecting pipeline between the two. An acid circulation pump (18) is provided in the liquid collecting tank (7) for mixing solid impurities with acid wastewater in the liquid collecting tank (7) to form a suspension and pumping it into the acid purification section (4), so that the suspension and the acid wastewater of the acid purification section (4) enter the acid filter (5) together.

4. An energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 2 or 3, characterized in that: Also includes: The neutralization tank (8) is connected to the liquid collecting tank (7) and is used as an emergency measure to neutralize the pH value of the wastewater in the liquid collecting tank (7) and then pump it to the sintering batching water pool.

5. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 1 is characterized in that: Also includes: The heat circulation fan (3) is connected between the hot air dispersing pipes of the regeneration reactor (2) and the hot air furnace (1) and is used for hot air circulation between the regeneration reactor (2) and the hot air furnace (1).

6. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 1 is characterized in that: An acid liquid regulating valve (12) is provided on the connecting pipe between the vaporizer (14) and the acid liquid filter (5) for regulating the flow rate of the acid liquid supernatant entering the vaporizer (14).

7. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 2 is characterized in that: A condensate discharge valve (15) is provided on the connecting pipe between the liquid collecting tank (7) and the vaporizer (14) for controlling the discharge of waste water containing solid impurities in the vaporizer (14).

8. The energy-saving activated carbon desulfurization and denitrification acid production wastewater treatment system according to claim 1 is characterized in that: The vaporizer (14) is a temperature-resistant and corrosion-resistant vaporizer.

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