Fluorine chemical waste gas quality-divided treatment system

Abstract

According to the fluorine chemical waste gas quality-divided treatment system provided by the utility model, fluorine chemical waste gas is classified and collected, different modules are adopted to carry out quality-divided treatment on different waste gas according to different characteristics, and hydrofluoric acid waste gas is recycled through the hydrofluoric acid waste gas treatment module; chlorine-containing organic matters are treated through the chlorine-containing organic waste gas treatment module, activated carbon is recycled and discharged after reaching the standard, the adsorption efficiency is improved, VOCs waste gas is treated through the VOCs waste gas treatment module, the characteristic of combustion heat of the VOCs waste gas is fully utilized, fuel use is reduced, and meanwhile different waste gas can all reach the emission standard.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field, especially to a fluorine chemical industry waste gas divides quality processing system. BACKGROUND

[0002] Fluorine chemical industry is an important part of chemical industry, involving the research, production and application of fluorine and its compounds, covering a wide range of fields from basic chemicals to high-end special materials. The importance of fluorine chemical industry in modern industry is increasing day by day, especially in the electronics, materials, refrigeration and environmental protection industries. The raw materials, catalysts and extractants in the production process of fluorine chemical industry will produce hydrogen fluoride acid-containing waste gas, VOCs waste gas and halogen-containing organic waste gas. Efficient treatment and standard emission of the above waste gas have become an important research direction of fluorine chemical industry waste gas treatment.

[0003] CN116785909A discloses a circulating spray system for treating fluorine-containing waste gas. After the fluorine-containing waste gas enters the circulating spray system, it reacts with the sodium hydroxide solution in the first spray tower to generate a solution containing sodium fluoride. The solution flows into the first sedimentation tank and reacts with the hydroxide or oxide therein to generate a water-insoluble fluoride salt precipitate. The supernatant after precipitation overflows into the second sedimentation tank, and the supernatant in the second sedimentation tank is returned to the spray tower for recycling. The invention has the problem of generating fluorine-containing precipitate, and there is no safeguard measure, which may pose a risk of non-compliance with emission standards.

[0004] CN116459637A discloses a fluorine chemical industry high-fluorine high-sulfur organic waste gas and waste liquid resourceization environmental protection treatment system and method. The treatment system includes a combustion furnace, a graphite quenching tower, an absorption tower, a first water washing tower, a second water washing tower, a first alkali washing tower, a second alkali washing tower, and a wet electric dust collector connected in sequence. The bottom outlet of the wet electric dust collector is connected to the second alkali washing tower, the top outlet of the wet electric dust collector is connected to the cold medium inlet of the GGH flue gas heat exchanger, the cold medium outlet of the GGH flue gas heat exchanger and the hot air furnace outlet are respectively connected to the flue gas mixer inlet, the flue gas mixer outlet is connected to the SCR denitration reactor inlet, the SCR denitration reactor outlet is connected to the hot medium inlet of the GGH flue gas heat exchanger, and the hot medium outlet of the GGH flue gas heat exchanger is connected to the chimney through an induced draft fan. The fluorine chemical industry high-fluorine high-sulfur organic waste gas and waste liquid resourceization environmental protection treatment system can recover fluorine and sulfur elements from waste gas and waste liquid to produce sulfuric acid solution and hydrofluoric acid solution. The invention requires high corrosion resistance for equipment as the fluorine-containing waste gas enters the combustion furnace, and the energy consumption is high as all waste gas is incinerated.

[0005] The existing waste gas treatment generally does not classify the waste gas, which may be all sprayed, activated carbon adsorbed, or all incinerated by RTO. Because of the large difference in composition and concentration of waste gas, both single disposal methods have different degrees of defects. UTILITY MODEL CONTENT

[0006] To this end, it is necessary to provide a fluorine chemical waste gas processing system, which solves the problem that the existing waste gas treatment generally does not classify waste gas, and all waste gas may be sprayed, activated carbon adsorption, or all waste gas enters the RTO incineration mode, because the composition and concentration of waste gas are quite different, and two single disposal methods have different degrees of defects.

[0007] To achieve the above object, the utility model provides a fluorine chemical waste gas processing system, comprising:

[0008] The hydrogen fluoride waste gas treatment module is used for receiving and processing hydrogen fluoride waste gas, and comprises a first pretreatment spraying unit, a first alkali washing tower, a first mist eliminator, an activated carbon tank, a first fan and a first exhaust cylinder connected in sequence according to the hydrogen fluoride waste gas treatment process;

[0009] The VOCs waste gas treatment module is used for receiving and processing VOCs waste gas, and comprises a second pretreatment spraying unit, a second fan, an RTO unit, a post-processing spraying unit, a third fan and a second exhaust cylinder connected in sequence according to the VOCs waste gas treatment process;

[0010] The chlorine-containing organic waste gas treatment module is used for receiving and processing chlorine-containing organic waste gas, and comprises a third pretreatment spraying unit, a third mist eliminator, a first heat exchanger, a fourth fan, an activated carbon adsorption and desorption unit, a second heat exchanger and a third exhaust cylinder connected in sequence according to the chlorine-containing organic waste gas treatment process.

[0011] Further, the first pretreatment spraying unit is composed of a first water washing tower, a second water washing tower and a third water washing tower.

[0012] Further, the second pretreatment spraying unit is composed of a second alkali washing tower and a fourth water washing tower.

[0013] Further, the post-processing spraying unit is composed of a third alkali washing tower and a fourth alkali washing tower.

[0014] Further, the third pretreatment spraying unit is composed of a fifth alkali washing tower and a fourth water washing tower.

[0015] Further, the first alkali washing tower, the second alkali washing tower, the third alkali washing tower, the fourth alkali washing tower and the fifth alkali washing tower are all provided with a pH meter and an automatic dosing device.

[0016] Further, the first water washing tower, the second water washing tower, the third water washing tower, the fourth water washing tower and the fourth alkali washing tower are all provided with a liquid level meter and an automatic water replenishing device.

[0017] Further, the activated carbon adsorption and desorption unit is composed of a plurality of activated carbon tanks.

[0018] Furthermore, the height of the first exhaust pipe, the second exhaust pipe, and the third exhaust pipe is 25m.

[0019] Unlike existing technologies, the above-mentioned technical solution classifies and collects fluorochemical waste gases and treats them separately according to their different characteristics using different modules. The hydrofluoric acid waste gas treatment module recovers and reuses the hydrofluoric acid waste gas, the chlorine-containing organic waste gas treatment module treats the chlorine-containing organic compounds, recycles activated carbon to meet emission standards and improves adsorption efficiency, and the VOCs waste gas treatment module treats the VOCs waste gas, making full use of its combustion heat characteristics to reduce fuel consumption, while ensuring that all waste gases meet emission standards. Attached Figure Description

[0020] Figure 1 This is a structural diagram of a fluorochemical waste gas separation and treatment system according to a specific embodiment;

[0021] Figure 2 Flowchart for the graded treatment of waste gas from fluorochemical industries;

[0022] Figure 3 This is a structural diagram of the hydrofluoric acid waste gas treatment module described in a specific embodiment;

[0023] Figure 4 The flowchart for the treatment of hydrofluoric acid waste gas in the specific implementation method is shown below.

[0024] Figure 5 This is a structural diagram of the VOCs waste gas treatment module described in a specific implementation method;

[0025] Figure 6 A flowchart illustrating the VOCs waste gas treatment process described in a specific implementation method;

[0026] Figure 7 This is a structural diagram of the chlorine-containing organic waste gas treatment module described in a specific implementation method;

[0027] Figure 8 This is a flowchart illustrating the treatment process for chlorine-containing organic waste gas as described in a specific implementation method.

[0028] Explanation of reference numerals in the attached figures:

[0029] 11. First water washing tower; 12. Second water washing tower; 13. Third water washing tower; 14. First alkali washing tower; 16. Activated carbon box; 17. First fan; 18. First exhaust stack; 21. Second alkali washing tower; 22. Fourth water washing tower; 23. Second fan; 24. RTO unit; 25. Third alkali washing tower; 26. Fourth alkali washing tower; 27. Third fan; 28. Second exhaust stack; 31. Fifth alkali washing tower; 32. Fourth water washing tower; 33. Entering the third demister; 34. First heat exchanger; 35. Fourth fan; 37. Activated carbon tank; 36. Second heat exchanger; 38. Third exhaust stack. Detailed Implementation

[0030] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following description is provided in conjunction with specific embodiments and accompanying drawings.

[0031] In this document, the term "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The term "embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment, nor does it specifically limit its independence or connection with other embodiments. In principle, in this application, as long as there are no technical contradictions or conflicts, the technical features mentioned in each embodiment can be combined in any way to form corresponding implementable technical solutions.

[0032] Unless otherwise defined, the technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the use of related terms herein is merely for the purpose of describing particular embodiments and is not intended to limit this application.

[0033] In the description of this application, the term "and / or" is used to describe the logical relationship between objects, indicating that three relationships can exist. For example, A and / or B means: A exists, B exists, and A and B exist simultaneously. Additionally, the character " / " in this document generally indicates that the preceding and following objects have an "or" logical relationship.

[0034] In this application, terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any actual quantity, hierarchy or order relationship between these entities or operations.

[0035] Unless otherwise specified, the use of terms such as “comprising,” “including,” “having,” or other similar expressions in this application is intended to cover non-exclusive inclusion, which does not exclude the presence of additional elements in a process, method, or product that includes the stated elements, such that a process, method, or product that includes a list of elements may include not only those defined elements but also other elements not expressly listed, or elements inherent to such a process, method, or product.

[0036] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than," "less than," and "exceeding" are understood to exclude the stated number; expressions such as "above," "below," and "within" are understood to include the stated number. Furthermore, in the description of the embodiments in this application, "multiple" means two or more (including two), and similar expressions related to "multiple" are also understood in this way, such as "multiple groups" and "multiple times," unless otherwise explicitly specified.

[0037] In the description of the embodiments of this application, the space-related expressions used, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "vertical," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiments or drawings. They are only for the purpose of describing the specific embodiments of this application or for the reader's understanding, and do not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0038] Unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," "fixing," and "setting," as used in the description of the embodiments of this application, should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. For those skilled in the art to which this application pertains, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0039] Please see Figures 1 to 8 This embodiment provides a fluorochemical waste gas separation and treatment system, including:

[0040] A hydrofluoric acid waste gas treatment module is used to receive and treat hydrofluoric acid waste gas. It includes a first pretreatment spray unit, a first alkaline scrubbing tower, a first demister, an activated carbon box, a first fan, and a first exhaust stack connected in sequence according to the hydrofluoric acid waste gas treatment process.

[0041] Furthermore, the first pretreatment spray device consists of a first water washing tower, a second water washing tower, and a third water washing tower. Each of the first, second, and third water washing towers is equipped with a level gauge and an automatic water replenishment device.

[0042] Furthermore, the first alkaline washing tower is equipped with a pH meter and an automatic dosing device.

[0043] The treatment process for hydrofluoric acid waste gas is as follows: After being collected, the hydrofluoric acid waste gas sequentially enters the first water scrubbing tower 11, the second water scrubbing tower 12, and the third water scrubbing tower 13. The first water scrubbing tower absorbs high concentrations of hydrofluoric acid gas, resulting in the highest concentration of hydrofluoric acid in the spray liquid. Once the absorbent reaches a certain concentration, it is discharged into a collection tank for recycling. Subsequently, the lower concentration spray liquid from the second water scrubbing tower is transferred back to the first water scrubbing tower for further absorption, and the spray liquid from the third water scrubbing tower is transferred back to the second water scrubbing tower for absorption. The third water scrubbing tower is replenished with fresh water, and the absorbent is transferred upwards stage by stage. The waste gas after the third water scrubbing tower is fed into the first alkaline scrubbing tower 14, which is used to neutralize the hydrofluoric acid gas brought in by incomplete absorption and demisting at its upstream end. After alkaline scrubbing, the gas enters the first demister 15 and the activated carbon box 16, where small amounts of slightly soluble or insoluble substances in the waste gas, as well as any acidic or alkaline waste gases, are absorbed. After meeting the emission standards for hydrogen fluoride in the exhaust gas, the exhaust gas is drawn in by the first fan 17 and discharged through the first exhaust stack 18.

[0044] The VOCs exhaust gas treatment module is used to receive and treat VOCs exhaust gas. It includes a second pretreatment spray unit, a second fan, an RTO unit, a post-treatment spray unit, a third fan, and a second exhaust stack connected in sequence according to the VOCs exhaust gas treatment process.

[0045] Furthermore, the second pretreatment spray unit consists of a second alkaline washing tower and a fourth water washing tower.

[0046] Furthermore, the post-treatment spray unit consists of a third alkaline washing tower and a fourth alkaline washing tower.

[0047] Furthermore, the second, third, and fourth alkaline washing towers are all equipped with pH meters and automatic dosing devices.

[0048] Furthermore, the fourth water washing tower is equipped with a level gauge and an automatic water replenishment device.

[0049] The VOCs waste gas treatment process is as follows: After collection, the VOCs waste gas is fed into the second pretreatment spray unit through a pipeline. The second pretreatment spray unit consists of a second alkaline scrubbing tower 21 and a fourth water scrubbing tower 22. The second alkaline scrubbing tower is equipped with a pH meter and an automatic dosing device. Alkali is added when the pH falls below the set value. The fourth water scrubbing tower is equipped with a level gauge and an automatic water replenishment device for high and low level control and water replenishment. The acidic gases in the VOCs gas are neutralized by the second pretreatment spray unit. After the pretreatment, the VOCs waste gas is fed into the RTO unit 24 through the second fan 23. It is rapidly heated and burned in the furnace, and the temperature is maintained at about 780℃-850℃. The VOCs waste gas is oxidized at high temperature. The VOCs exhaust gas after combustion oxidation is connected to a post-treatment spray unit, which consists of a third alkaline scrubbing tower 25 and a fourth alkaline scrubbing tower 26. In the RTO unit, the VOCs exhaust gas is oxidized and decomposed into CO2 and H2O, but some secondary pollutants, such as nitrogen oxides, may be generated in the process. The post-treatment spray unit can further treat the exhaust gas after RTO treatment to ensure that the emission gas meets environmental protection standards. Finally, it is discharged through a third fan 27 and a second exhaust stack 28.

[0050] The chlorinated organic waste gas treatment module is used to receive and treat chlorinated organic waste gas. It includes a third pretreatment spray unit, a third demister, a first heat exchanger, a fourth fan, an activated carbon adsorption-desorption unit, a second heat exchanger, and a third exhaust stack, which are connected in sequence according to the chlorinated organic waste gas treatment process.

[0051] Furthermore, the third pretreatment spray unit consists of a fifth alkaline washing tower and a fifth water washing tower. The first alkaline washing tower is equipped with a pH meter and an automatic dosing device, and the fifth water washing tower is equipped with a level gauge and an automatic water replenishment device.

[0052] Furthermore, the activated carbon adsorption-desorption unit consists of multiple activated carbon canisters.

[0053] The treatment process for chlorinated organic waste gas is as follows: After being collected, the chlorinated organic waste gas sequentially enters the fifth alkaline scrubbing tower 31 and the fourth water scrubbing tower 32 of the third pretreatment spray unit, which neutralize the acidic waste gas and absorb water-soluble substances. After pretreatment in the third pretreatment spray unit, the chlorinated organic waste gas sequentially enters the third demister 33 for demisting, and after preheating in the first heat exchanger 34, it enters the activated carbon adsorption-desorption unit via the fourth fan 35. The activated carbon adsorption-desorption unit consists of multiple activated carbon tanks 37. Taking three activated carbon tanks as an example, they are respectively in a "one adsorption, two desorption, three standby" state. The "one adsorption" refers to the adsorption process, in which the chlorinated organic waste gas enters the activated carbon tank from bottom to top and fully reacts with the activated carbon. The second step involves desorption. Saturated steam at 0.6 MPa enters the saturated activated carbon tank from top to bottom. The high-temperature, high-pressure steam desorbs organic matter from the activated carbon. The high-temperature waste gas containing organic matter then enters a two-stage condenser (i.e., through the second heat exchanger 36), where the organic matter condenses into an oil-water mixture. For single chlorinated organic waste gases, oil-water stratification can be achieved through recycling; for multiple chlorinated organic waste gases, stratification is less pronounced. The desorbed activated carbon tank is initially damp and requires drying with hot air. After drying, it can be used as a backup tank. Multiple activated carbon tanks can be automatically switched, allowing simultaneous adsorption, desorption, and drying operations to improve treatment efficiency. Finally, the waste gas is discharged through the third exhaust stack 38.

[0054] Furthermore, the height of the first, second, and third exhaust pipes is 25m. This height meets the exhaust emission requirements.

[0055] By classifying and collecting fluorochemical waste gases and treating them according to their different characteristics using different modules, hydrofluoric acid waste gas is recycled and reused, chlorinated organic waste gas is treated by a chlorine-containing organic waste gas treatment module, activated carbon is recycled and emissions meet standards, and adsorption efficiency is improved. VOCs waste gas is treated by a VOCs waste gas treatment module, making full use of its combustion heat characteristics, reducing fuel consumption, and ensuring that all waste gases meet emission standards.

[0056] It should be noted that the first, second, third, and fourth water washing towers, as well as the fourth alkaline washing tower, can all adopt existing common water washing tower structures. The structural components of the water washing tower can be referenced as follows: Tower body: The main body of the water washing tower, used to house the packing layer and spray system, and also serves as the channel for the entry of waste gas and the exit of purified gas. Packing layer: Located inside the tower body, it is the core part of the water washing tower. The packing layer improves purification efficiency by increasing the gas-liquid contact area. The packing can be a tower plate, packing, or baffle plate, etc. Common packings include irregular ring packing and corrugated plate packing. Spray system: The washing liquid is evenly sprayed onto the packing layer through nozzles, forming a liquid film that contacts the gas, allowing pollutants in the waste gas to dissolve or be adsorbed into the water during contact. Bottom sewage system: Used to collect and discharge wastewater at the bottom of the tower for subsequent treatment or discharge. Exhaust pipe: The purified gas is discharged outside the tower through the exhaust pipe, meeting environmental emission standards. Liquid level control system: used to adjust the flow rate and volume of the washing liquid to ensure proper circulation of the liquid within the washing tower.

[0057] It should be noted that the first, second, third, fourth, and fifth alkaline scrubbing towers can all adopt existing common alkaline scrubbing tower structures. The structural components can be referenced as follows: Tower body: The tower body of the alkaline scrubbing tower is usually constructed of a cylindrical or square container, made of corrosion-resistant materials such as stainless steel or fiberglass. Packing layer: A certain amount of packing material is added inside the tower to ensure sufficient contact between the waste gas and the scrubbing liquid, increasing the gas-liquid contact area and improving absorption efficiency. Spray layer: The alkaline scrubbing tower is designed with a spray layer inside, which evenly sprays the alkaline scrubbing liquid through nozzles, forming a liquid film that contacts the gas, enhancing the absorption effect on acidic gases. Demisting layer: Located at the top of the tower body, it is used to remove droplets carried after scrubbing, ensuring clean exhaust gas discharge. Observation window and maintenance port: Used to observe the internal conditions of the tower and facilitate maintenance. Circulating water pump and circulating water tank: Used to circulate the alkaline solution, ensuring that the alkaline solution can continuously contact the waste gas for neutralization reaction. The chemical storage and dosing system is used to store and add alkaline solutions, such as sodium hydroxide, to maintain the neutralization capacity of the washing liquid. A gas sensor and automatic control system are included; the gas sensor at the outlet monitors gas quality and, connected to the control system, automatically adjusts the operation of the alkaline spray device, circulation device, and automatic feeding device to optimize the treatment effect. The inlet and outlet systems are used to introduce waste gas and discharge clean gas after washing, respectively.

[0058] The

[0059] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this utility model. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this utility model, or equivalent structural or procedural transformations made using the content of this utility model's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this utility model patent.

Claims

1. A fluorochemical waste gas separation and treatment system, characterized in that, include: A hydrofluoric acid waste gas treatment module is used to receive and treat hydrofluoric acid waste gas. It includes a first pretreatment spray unit, a first alkaline scrubbing tower, a first demister, an activated carbon box, a first fan, and a first exhaust stack connected in sequence according to the hydrofluoric acid waste gas treatment process. The VOCs exhaust gas treatment module is used to receive and treat VOCs exhaust gas. It includes a second pretreatment spray unit, a second fan, an RTO unit, a post-treatment spray unit, a third fan, and a second exhaust stack connected in sequence according to the VOCs exhaust gas treatment process. The chlorinated organic waste gas treatment module is used to receive and treat chlorinated organic waste gas. It includes a third pretreatment spray unit, a third demister, a first heat exchanger, a fourth fan, an activated carbon adsorption-desorption unit, a second heat exchanger, and a third exhaust stack, which are connected in sequence according to the chlorinated organic waste gas treatment process.

2. The fluorochemical waste gas separation and treatment system according to claim 1, characterized in that: The first pretreatment spray unit consists of a first water washing tower, a second water washing tower, and a third water washing tower.

3. The fluorochemical waste gas separation and treatment system according to claim 2, characterized in that: The second pretreatment spray unit consists of a second alkaline washing tower and a fourth water washing tower.

4. The fluorochemical waste gas separation and treatment system according to claim 3, characterized in that: The post-treatment spray unit consists of a third alkaline washing tower and a fourth alkaline washing tower.

5. The fluorochemical waste gas separation and treatment system according to claim 4, characterized in that: The third pretreatment spray unit consists of a fifth alkaline washing tower and a fifth water washing tower.

6. The fluorochemical waste gas separation and treatment system according to claim 5, characterized in that: The first, second, third, fourth, and fifth alkaline washing towers are all equipped with pH meters and automatic dosing devices.

7. The fluorochemical waste gas separation and treatment system according to claim 5, characterized in that: The first, second, third, fourth, and fifth water washing towers are all equipped with level gauges and automatic water replenishment devices.

8. The fluorochemical waste gas separation and treatment system according to claim 1, characterized in that: The activated carbon adsorption-desorption unit consists of multiple activated carbon tanks.

9. The fluorochemical waste gas separation and treatment system according to claim 1, characterized in that: The height of the first exhaust pipe, the second exhaust pipe, and the third exhaust pipe is 25m.

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