Sewage lagoon off-gas treatment system
Patent Information
- Application Number
- CN202522536487.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-10-23
- Estimated Expiration
- 2035-11-28
AI Technical Summary
[0005]本实用新型提供一种污水池尾气处理系统，用以解决现有技术中污水池逸散出的未经处理的尾气造成的环境污染和安全隐患的问题
[0014]本实用新型提供的污水池尾气处理系统，以“收集-喷淋预处理-核心吸附净化-达标排放”为工作逻辑，通过系统化步骤实现恶臭及有害气体的高效治理，喷淋洗涤去除尾气中的可溶性污染物、杂质与水分，吸附单元对尾气中的VOCs、恶臭物质等进行高效吸附，将污水池尾气中的VOCs净化，以实现VOCs的达标排放，净化效率高，环保效益显著，也消除了尾气直接排放的安全隐患，系统流程操作简单，运行成本低，系统运行安全又经济。
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Figure CN224877667U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a wastewater tank exhaust gas treatment system. Background Technology
[0002] In existing technologies, the anthraquinone process is the most important method for producing hydrogen peroxide. The process involves preparing a working solution of alkyl anthraquinone with an organic solvent, and then hydrogenating it by introducing hydrogen gas under conditions of 0.30 MPa pressure, 55-65℃ temperature, and the presence of a catalyst. The solution is then subjected to countercurrent oxidation with air (or oxygen) at 40-44℃. After extraction, regeneration, purification, and concentration, a hydrogen peroxide aqueous solution with a mass fraction of 20-30% is obtained.
[0003] In the anthraquinone process for hydrogen peroxide production, some impurities need to be intermittently discharged from the production system. These mainly include: wastewater from the oxidation tower, raffinate metering tank, alkali separator, clay bed, and working fluid preparation vessel. The wastewater pond is the final destination for these discharges. During the discharge process, the wastewater carries some working fluid and solvent. After collection in the wastewater pond and preliminary solvent recovery, the wastewater is then sent to the wastewater treatment unit for purification. The wastewater pond contains the continuous aggregation of organic matter, including heavy aromatics (mainly composed of trimethylbenzene, ethylbenzene, propylbenzene, xylene, and other aromatic compounds, as well as small amounts of monoethylanthraquinone and other organic compounds). Because some components of heavy aromatics are volatile and easily form explosive mixtures, the wastewater pond is generally designed as an open system. This results in the long-term volatilization of organic VOCs around the wastewater pond, seriously threatening environmental safety. Furthermore, most VOCs are carcinogenic pollutants; if discharged into the atmosphere without treatment, they will seriously harm human health and cause significant environmental damage and pollution.
[0004] Therefore, the efficient treatment of VOCs exhaust gas generated from sewage ponds is also an important aspect of sewage treatment. Utility Model Content
[0005] This invention provides a wastewater tank exhaust gas treatment system to solve the environmental pollution and safety hazards caused by untreated exhaust gas escaping from wastewater tanks in the prior art.
[0006] This utility model provides a wastewater tank exhaust gas treatment system, comprising: a fixed cover that fully covers the top of the wastewater tank, a gas collection pipe on the fixed cover, and a blower connected to the other end of the gas collection pipe; the outlet of the blower is connected to the air inlet in the middle of a spray tower, and the air outlet at the top of the spray tower is connected to the inlet of a demister; the outlet of the demister is connected to the air inlet of an adsorption unit, and the air outlet of the adsorption unit is connected to an exhaust stack for high-altitude emission of exhaust gas.
[0007] Furthermore, the wastewater tank is equipped with a VOC sensor and a pressure sensor; the fixed cover is equipped with at least one air inlet, and an air inlet valve is connected to the air inlet.
[0008] Furthermore, the upper part of the spray tower is equipped with spraying components, which are connected to the bottom of the spray tower via a circulating pump; the inlet of the circulating pump is also connected to the industrial water network of the plant area via a water supply pipeline; and the outlet of the circulating pump is also connected to the wastewater collection tank of the wastewater treatment unit.
[0009] Furthermore, the adsorption unit includes a primary adsorber and a secondary adsorber connected in series. The inlet of the primary adsorber is connected to the outlet of the demister, and the outlet of the secondary adsorber is connected to the exhaust stack.
[0010] Furthermore, the primary adsorber is filled with columnar activated carbon, and the secondary adsorber is filled with granular activated carbon.
[0011] Furthermore, the regeneration inlets of the primary and secondary adsorbers are connected to the heat medium pipeline; the regeneration outlets of the primary and secondary adsorbers are both connected to the vacuum pump, the outlet of the vacuum pump is connected to the inlet of the condenser, the outlet of the condenser is connected to the solvent tank, and the top of the solvent tank is equipped with a return gas port, which is connected to the exhaust stack through a pipe.
[0012] Furthermore, the fixed cover is provided with at least one observation port, which is sealed with glass; the top of the fixed cover has a conical structure.
[0013] Furthermore, the pressure sensor and the air supply valve are also electrically connected to the controller.
[0014] The wastewater treatment system provided by this utility model operates on the logic of "collection-spray pretreatment-core adsorption purification-compliant emission". Through systematic steps, it achieves efficient treatment of odorous and harmful gases. Spray washing removes soluble pollutants, impurities and moisture from the exhaust gas. The adsorption unit efficiently adsorbs VOCs and odorous substances in the exhaust gas, purifying the VOCs in the wastewater treatment system exhaust gas to achieve VOCs compliant emission. The purification efficiency is high, the environmental benefits are significant, and the safety hazards of direct exhaust gas emission are eliminated. The system process is simple to operate, has low operating costs, and is safe and economical to operate.
[0015] The system automatically adjusts the opening of the air supply valve based on pressure sensor data to maintain airflow and a slightly negative pressure environment within the fixed cover, preventing exhaust gas leakage, improving treatment efficiency and stability, reducing the need for manual intervention, and achieving automated and intelligent operation management. Furthermore, desorption of VOCs from the activated carbon surface via a heat transfer medium in the two-stage adsorber results in high-concentration exhaust gas. Desorption restores over 90% of the activated carbon's adsorption capacity, reducing replacement costs. The desorbed high-concentration VOCs exhaust gas is transported to a condenser for condensation, and the condensed VOCs condensate is stored in a solvent tank for secondary treatment and recycling in the workshop, further reducing production costs. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the structure of a wastewater tank exhaust gas treatment system provided in one embodiment of the present invention; Figure 2 A schematic diagram of the structure of the sewage tank and fixed cover provided in one embodiment of this utility model; Figure 3 This is a schematic diagram of the structure of a sewage tank exhaust gas treatment system provided in another embodiment of the present invention.
[0018] Explanation of reference numerals in the attached figures: 1. Wastewater tank; 2. Fixed cover; 3. Fan; 4. Spray tower; 5. Demister; 6. Exhaust stack; 7. Primary adsorber; 8. Secondary adsorber; 21. VOC sensor; 22. Pressure sensor; 23. Make-up air inlet; 24. Make-up air valve; 25. Controller; 41. Spray components; 42. Circulation pump; 43. Make-up water pipeline; 44. Wastewater collection tank; 71. Heat medium pipeline; 72. Vacuum pump; 73. Condenser; 74. Solvent tank. Detailed Implementation
[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are also within the protection scope of this utility model.
[0020] like Figure 1 and Figure 3 This utility model discloses a wastewater tank exhaust gas treatment system, comprising: a fixed cover 2 that fully covers the top of the wastewater tank 1, the fixed cover 2 having an air collection pipe, the other end of which is connected to a blower 3; the outlet of the blower 3 being connected to the air inlet in the middle of a spray tower 4, the air outlet at the top of the spray tower 4 being connected to the inlet of a demister 5; the outlet of the demister 5 being connected to the air inlet of an adsorption unit, the air outlet of the adsorption unit being connected to an exhaust stack 6, the exhaust stack 6 being used for high-altitude emission of exhaust gas.
[0021] A fixed cover 2 completely covers the sewage tank 1, creating a sealed collection space. The accompanying gas collection pipes and fan 3 form a negative pressure system, centrally extracting odorous gases and VOCs volatile within the tank, preventing unorganized diffusion at the source and ensuring all gases enter the treatment system. This prevents both the accumulation of organic waste gas and the potential for explosion, as well as the emission of waste gas and air pollution. The collected exhaust gas first passes through a spray tower 4, where soluble pollutants, impurities, and moisture are removed. Then, after dehumidification by a demister 5, it enters an adsorption unit for deep purification. The adsorption unit efficiently adsorbs VOCs and odorous substances from the exhaust gas, significantly reducing pollutant concentrations and ensuring that all indicators of the purified exhaust gas meet relevant national or local emission standards. Finally, it is discharged at high altitude through an exhaust stack 6, further reducing the impact on the surrounding environment and human health.
[0022] The aforementioned wastewater treatment system operates on a "collection-spray pretreatment-core adsorption purification-compliant emission" logic. Through a systematic approach, it efficiently treats odorous and harmful gases (VOCs), purifying the VOCs in the wastewater tank 1's exhaust gas to achieve compliant emissions. The system boasts high purification efficiency, significant environmental benefits, and eliminates the safety hazards of direct exhaust gas emissions. The system is safe and economical to operate. The demister 5 in the system can be replaced with a dehumidifier offering better dehumidification; the specific choice will be made by technicians based on production conditions to avoid excessively high exhaust gas humidity, which could reduce the adsorption efficiency of the packing material in the adsorption unit and affect the overall purification effect.
[0023] like Figure 2In one embodiment, the wastewater tank 1 is equipped with a VOC sensor 21 and a pressure sensor 22; the fixed cover 2 is equipped with at least one air inlet 23, and an air inlet valve 24 is connected to the air inlet 23. The VOC sensor 21 can monitor the VOC concentration in the wastewater tank 1, and the pressure sensor 22 can monitor the pressure change inside the fixed cover 2 above the wastewater tank 1. When the monitored VOC concentration or pressure value reaches a preset threshold, the blower 3 and the entire exhaust gas treatment system are started to begin exhaust gas purification. The air inlet 23 and the air inlet valve 24 can timely supply fresh air from outside into the fixed cover 2, so that the air inside the fixed cover 2 can circulate and always maintain a slightly negative pressure environment, preventing exhaust gas leakage and ensuring the air quality of the surrounding environment.
[0024] like Figure 3 In one embodiment, the upper part of the spray tower 4 is equipped with a spray element 41, which is connected to the bottom of the spray tower 4 via a circulating pump 42. The inlet of the circulating pump 42 is also connected to the industrial water network of the plant area via a water supply pipeline 43. The outlet of the circulating pump 42 is also connected to the wastewater collection tank 44 of the wastewater treatment unit. The spray tower 4 uses clean water to spray the exhaust gas, which can initially absorb the soluble pollutants in it, reduce the impurity content in the exhaust gas, and prevent impurities and moisture from clogging pipes or corroding equipment, thus laying the foundation for subsequent purification. The spray water is recycled through the circulating pump 42 and the spray element 41. The circulating liquid is replaced regularly, and fresh water is added from the industrial water network. The replaced waste liquid is discharged into the wastewater treatment unit for purification treatment before being discharged in compliance with standards.
[0025] like Figure 3 In one embodiment, the adsorption unit includes a primary adsorber 7 and a secondary adsorber 8 connected in series. The inlet of the primary adsorber 7 is connected to the outlet of the demister 5, and the outlet of the secondary adsorber 8 is connected to the exhaust stack 6. The primary adsorber 7 and the secondary adsorber 8 form a series flow, and the exhaust gas passes through the two adsorbers sequentially. In this way, the VOCs in the exhaust gas meet emission standards after being treated by activated carbon adsorption. The adsorbers that adsorb VOCs can be desorbed and the organic matter can be recovered, reducing production costs.
[0026] In one embodiment, the primary adsorber 7 is filled with columnar activated carbon, and the secondary adsorber 8 is filled with granular activated carbon. Activated carbon is the core adsorption material of the adsorbers. Activated carbon, with its large specific surface area and abundant pore structure, efficiently adsorbs VOCs and odorous substances in the exhaust gas, significantly reducing pollutant concentrations. Granular activated carbon, with its richer micropores, has a stronger adsorption capacity for small-molecule pollutants, while columnar activated carbon, with its well-developed mesopores, is more suitable for large-molecule pollutants. Through the cooperation of the two-stage adsorbers, VOCs can be fully captured, ultimately ensuring that the exhaust gas meets emission standards.
[0027] like Figure 3In one embodiment, the regeneration inlets of the primary adsorber 7 and the secondary adsorber 8 are connected to the heat medium pipeline 71; the regeneration outlets of the primary adsorber 7 and the secondary adsorber 8 are both connected to the vacuum pump 72, the outlet of the vacuum pump 72 is connected to the inlet of the condenser 73, the outlet of the condenser 73 is connected to the solvent tank 74, the top of the solvent tank 74 is provided with a return air port, and the return air port is connected to the exhaust stack 6 through a pipe.
[0028] Once the activated carbon is saturated, desorption is performed using a heat transfer medium (such as hot nitrogen or steam) to desorb VOCs from the activated carbon surface, forming high-concentration waste gas. Desorption can restore more than 90% of the activated carbon's adsorption capacity, reducing replacement costs. During desorption, the heat transfer medium heats the activated carbon, while the adsorber is evacuated to a vacuum state by a vacuum pump 72. As the vacuum level and temperature inside the adsorber increase, VOCs gas is desorbed from the activated carbon. The desorbed high-concentration VOCs tail gas is sent to a condenser 73 for condensation. The condensed VOCs condensate is then sent to a solvent tank 74 for storage, allowing for secondary treatment and recycling in the workshop, thus reducing production costs. The separated non-condensable gases can be directly vented through an exhaust stack 6. The vacuum pump 72 can be a Roots vacuum pump 72, which has the advantages of fast start-up, large suction volume, and high efficiency.
[0029] In one embodiment, the fixed cover 2 is provided with at least one observation port, which is sealed with glass; the top of the fixed cover 2 is a conical structure. The condition of the collected liquid in the sewage tank 1 can be observed through the observation port, and the conical top guides the flow of gas, so that the gas containing VOCs can flow quickly to the gas collection pipe, reducing the possibility of VOCs remaining in the fixed cover 2.
[0030] like Figure 2 In one embodiment, the pressure sensor 22 and the make-up air valve 24 are also electrically connected to the controller 25. The controller 25 and its control system automatically adjust the opening of the make-up air valve 24 based on the data from the pressure sensor 22 to maintain airflow and a slightly negative pressure environment within the fixed cover 2, preventing exhaust gas leakage, improving processing efficiency and stability, reducing the need for manual intervention, and achieving automated and intelligent operation management. The controller 25 and its control system are existing technologies and will not be described in detail here.
[0031] It should be noted that arrows without attached labels indicate the flow direction of the gas-liquid mixture, gas phase, or liquid phase. The structure of spray tower 4 and the adsorption unit, along with their supporting equipment, are derived from existing technologies and will not be elaborated upon or limited here.
[0032] The wastewater tank 1 exhaust gas treatment system, in its specific operation, fully covers the wastewater tank 1 through a fixed cover 2 on top, creating a sealed collection space. The fixed cover 2 effectively seals and collects the exhaust gas from the wastewater tank 1 area. When the monitored VOC concentration or pressure value reaches a preset threshold, the blower 3 and the entire exhaust gas treatment system are activated to begin exhaust gas purification. The gas collection pipes on the fixed cover 2 and the blower 3 can form a negative pressure system, concentrating and extracting the odorous gases and VOCs volatilized in the tank. The controller 25 and its control system automatically adjust the opening of the air supply valve 24 based on the data from the pressure sensor 22 to maintain air circulation and a slightly negative pressure environment within the fixed cover 2, preventing exhaust gas leakage. The collected exhaust gas first passes through the spray tower 4, where it is sprayed and washed to remove soluble pollutants, impurities, and moisture. Then, after being dehumidified by the demister 5, it enters the primary adsorber 7 and the secondary adsorber 8 in sequence. The activated carbon in the adsorbers efficiently adsorbs VOCs, malodorous substances, etc. in the exhaust gas. The adsorbed exhaust gas is then discharged at high altitude through the exhaust stack 6 to meet emission standards.
[0033] When the exhaust gas passes through the spray tower 4, the spray tower 4 uses clean water to spray the exhaust gas. The spray water is recycled through the circulating pump 42 and the spraying components 41. The circulating liquid is replaced regularly, and fresh water is added from the industrial water network. The waste liquid that is replaced is discharged into the wastewater collection tank 44 of the wastewater treatment unit for purification treatment before being discharged in compliance with standards.
[0034] When the activated carbon in the primary adsorber 7 and the secondary adsorber 8 is saturated, it is heated by a heat medium (such as hot nitrogen or steam). At the same time, the adsorber is evacuated to a vacuum state by a vacuum pump 72. As the vacuum degree and temperature inside the adsorber increase, VOCs gas is desorbed from the activated carbon. The desorbed high-concentration VOCs tail gas is sent to the condenser 73 for condensation. The condensed VOCs condensate is sent to the solvent tank 74 for storage and recycling in the workshop after secondary treatment, which reduces production costs. The separated non-condensable gas can be directly vented through the exhaust stack 6.
[0035] It should be noted that the detailed structure of some devices in this utility model is not described in detail, but belongs to the prior art known to those skilled in the art, and therefore will not be described again here. In addition, the parts of this device not described are the same as or can be implemented using existing technology.
[0036] It should be noted that pressure sensors, flow meters, or temperature sensors are installed on the conveying pipelines inside the system between different units, devices, or equipment. Various valves, such as pressure relief valves, pressure regulating valves, and safety valves, are also installed to regulate and stabilize the pressure of the entire system.
[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it; although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. A wastewater treatment system for exhaust gas from a sewage tank, characterized in that, include: A fixed cover is installed to fully cover the top of the sewage tank. The fixed cover is equipped with a gas collection pipe, and the other end of the gas collection pipe is connected to a fan. The outlet of the fan is connected to the air inlet in the middle of the spray tower, and the air outlet at the top of the spray tower is connected to the inlet of a demister. The outlet of the demister is connected to the air inlet of the adsorption unit, and the air outlet of the adsorption unit is connected to an exhaust stack for high-altitude emission of exhaust gas.
2. The wastewater treatment system for tail gas from a sewage tank according to claim 1, characterized in that, The wastewater tank is equipped with a VOC sensor and a pressure sensor; the fixed cover is provided with at least one air inlet, and an air inlet valve is connected to the air inlet.
3. The wastewater tank exhaust gas treatment system according to claim 1, characterized in that, The upper part of the spray tower is equipped with a spraying element, which is connected to the bottom of the spray tower via a circulating pump; the inlet of the circulating pump is also connected to the industrial water network of the plant area via a water supply pipeline; the outlet of the circulating pump is also connected to the wastewater collection tank of the wastewater treatment unit.
4. The wastewater treatment system for tail gas from a sewage tank according to claim 1, characterized in that, The adsorption unit includes a primary adsorber and a secondary adsorber connected in series. The inlet of the primary adsorber is connected to the outlet of the demister, and the outlet of the secondary adsorber is connected to the exhaust stack.
5. The wastewater tank exhaust gas treatment system according to claim 4, characterized in that, The primary adsorber is filled with columnar activated carbon, and the secondary adsorber is filled with granular activated carbon.
6. The wastewater tank exhaust gas treatment system according to claim 4, characterized in that, The regeneration inlets of the primary and secondary adsorbers are connected to the heat medium pipeline; the regeneration outlets of the primary and secondary adsorbers are both connected to a vacuum pump, the outlet of the vacuum pump is connected to the inlet of the condenser, the outlet of the condenser is connected to the solvent tank, the top of the solvent tank is provided with a return gas port, and the return gas port is connected to the exhaust stack through a pipe.
7. The wastewater treatment system for exhaust gas from a sewage treatment plant according to any one of claims 1-6, characterized in that, The fixed cover is provided with at least one observation port, which is sealed with glass; the top of the fixed cover has a conical structure.
8. The wastewater tank exhaust gas treatment system according to claim 2, characterized in that, The pressure sensor and the air supply valve are also electrically connected to the controller.