Waste gas treatment system for curing roasting and use and control method

Abstract

The invention relates to the field of waste gas treatment, and discloses a waste gas treatment system for curing and roasting and a use and control method thereof.The waste gas firstly enters quenching equipment for quenching and cooling treatment, the waste gas subjected to primary cooling and washing enters alkali washing equipment, and residual acidic substances and water-soluble substances in the waste gas are removed; the treated waste gas can carry a certain amount of liquid drops, the waste gas is introduced into demisting equipment and subjected to efficient demisting treatment, most of water vapor in the gas is removed, it is guaranteed that the emission concentration of sulfuric acid mist and the like reaches the standard, and the treated gas reaching the standard is sucked by a static pressure fan and is led to the high altitude through a chimney of an emission tower to be emitted.

Description

Technical Field

[0001] The present invention relates to the field of waste gas treatment, and in particular to a waste gas treatment system for treating aging and roasting and a use and control method thereof. Background Art

[0002] Many industrial production, sewage, treatment and garbage disposal processes will generate a large amount of waste gas containing organic matter (VOCs). In the production and processing of chemical, pharmaceutical, coating, semiconductor and printing industries, as organic solvents evaporate, a large amount of volatile organic compounds, namely VOCs waste gas, will be generated. If VOCs waste gas is directly discharged into the atmosphere, it will not only seriously pollute the air environment, but its VOCs gas molecules will also react with sunlight, ozone, etc. to form harmful organic particles, which will further damage the atmosphere and have a very adverse effect on the environment and human body. Therefore, VOCs waste gas generated in industrial production must be treated before it can be discharged into the atmosphere to protect the environment and human health.

[0003] Natural gas is used as fuel in the push-plate kiln maturation process. The production process is the battery black powder concentrated sulfuric acid maturation roasting. Under high temperature and strong acid conditions, the organic binder, additive or impurity in the battery material may undergo decomposition reaction to generate volatile organic compounds (VOCs) containing acidic components such as sulfur, which can easily cause serious pollution to the atmosphere. The domestic (VOCs) environmental protection management industry has been developing for many years, and the overall progress is slow. One of the main obstacles is that the recovery of solvents is mostly accompanied by deterioration such as acid change, color development, stench, and high water content. The existing organic solvent recovery and treatment methods and devices have very low treatment yields and no economic benefits.

[0004] In response to the problem of controlling volatile organic compounds with acidic components such as sulfur, the industry has conducted relevant research and designs, such as an acidified flue gas acid mist and dust low emission device (202021678572.2). The acidic flue gas collector is connected to the dust collector, and the outlet of the dust collector is connected to the quenching pipe flusher, the quenching pipe flusher is connected to the venturi scrubber, the venturi scrubber is connected to the packed washing tower, the packed tower washing tower is connected to the absorption tower, the absorption tower is connected to the electrostatic precipitator and the front high dust washing liquid transmitter, the electrostatic precipitator is connected to the fan, and the fan is connected to the chimney; sulfuric acid mist, sulfur trioxide and sulfur dioxide are treated separately to reduce the consumption of water and alkali; a cooling device and a sedimentation device are set at the packed tower position to achieve data de-whitening.

[0005] However, in the above-mentioned prior art, the temperature of the exhaust gas generated by the push-plate kiln and the mixer is about 400°C. When the high-temperature exhaust gas of 400°C enters the quenching pipe, due to the small heat dissipation area of ​​the quenching pipe, the local heat load of the quenching pipe may be too high, resulting in damage, deformation or degradation of material properties, posing a safety hazard; and, the electrostatic demister of the device is prone to accumulate dust and fog particles during demisting work, which is prone to blockage, resulting in incomplete dust removal and other technical defects, thereby reducing the ability to control VOCs. Summary of the invention

[0006] The present invention is to overcome the technical problems existing in the above-mentioned prior art and is a waste gas treatment system for treating aging and roasting;

[0007] Another object of the present invention is to provide a method for using a waste gas treatment system for treating aging and roasting;

[0008] Another object of the present invention is to provide a control method for a waste gas treatment system for treating aging and roasting.

[0009] In order to solve the above technical problems, the technical solution of the present invention is as follows:

[0010] A waste gas treatment system for treating aging and roasting, comprising:

[0011] Rapid cooling equipment, alkali washing equipment, demisting equipment, alkaline water system and discharge tower; the rapid cooling equipment is connected to the exhaust gas through a treatment pipeline, the alkali washing equipment is connected to the rapid cooling equipment through a treatment pipeline, the demisting equipment is connected to the alkali washing equipment through a treatment pipeline, and the discharge tower is connected to the demisting equipment through a treatment pipeline. A centrifugal fan and a pressure transmitter are provided on the treatment pipeline, and the pressure feedback value of the pressure transmitter automatically controls the working frequency of the centrifugal fan; an exhaust gas detection device is also provided between the discharge tower and the treatment pipeline;

[0012] The alkaline water system and the quenching equipment are also connected to a quenching water tank through a water pump, which is used to configure alkaline water to cool the exhaust gas and perform preliminary alkali washing;

[0013] The alkaline water system and the alkaline washing equipment are also connected to an alkaline washing water tank through a water pump, so as to prepare alkaline water for alkaline washing of the waste gas;

[0014] The alkaline water system and the demisting device are also connected to a demisting water tank through a water pump, which is used to prepare alkaline water to clean the dust and fog particles inside the demisting device;

[0015] The quenching water tank and the alkali washing water tank are also connected to the wastewater discharge area through a sewage pump.

[0016] Furthermore, it also includes a heat exchange system, which includes a compressor, a first heat exchanger, a throttle valve and a second heat exchanger;

[0017] The first heat exchanger is connected to the compressor outlet, the second heat exchanger is connected to the first heat exchanger through a throttle valve, and the second heat exchanger is connected to the compressor;

[0018] The alkaline water system is also connected to the quenching water tank through the second heat exchanger to provide low-temperature alkaline water to the quenching water tank;

[0019] The alkaline water system is also connected to the alkaline washing water tank through the first heat exchanger to provide alkaline water with slightly higher temperature for the alkaline washing water tank.

[0020] Furthermore, the demisting equipment is a wet electrostatic demisting equipment, the dust collecting electrode of the demisting equipment absorbs and collects the acidic smoke, and the demisting water tank sprays and cleans the dust collecting electrode of the demisting equipment through a nozzle.

[0021] Furthermore, the quenching water tank is connected to the alkaline water system through a water replenishment electric valve and a drug dosing electric valve. A pH detector and a liquid level meter for measuring alkaline water are provided in the quenching water tank. A flow meter for measuring water flow is provided at the connection between the quenching water tank and the alkaline water system. The quenching water tank also provides alkaline water to the quenching equipment through a first water pump for cooling.

[0022] Furthermore, a water replenishment electric valve and a drug dosing electric valve are provided between the alkaline washing water tank and the alkaline water system, a pH detector and a liquid level meter for measuring alkaline water are provided in the alkaline washing water tank, and a flow meter for measuring water flow is provided at the connection between the alkaline washing water tank and the alkaline water system; the alkaline washing water tank also provides alkaline water to the quenching equipment through a second water pump for removing acidic gases.

[0023] Preferably, the demister water tank is provided with a pH detector and a liquid level meter for measuring alkaline water, and the demister water tank is provided with a flow meter for measuring water flow at the connection with the sewage pump.

[0024] Furthermore, a water replenishment electric valve and a drug addition electric valve are provided between the demisting water tank and the alkaline water system, a float measuring device is provided in the demisting water tank, and the demisting water tank also provides alkaline water for cleaning to the demisting equipment through a third water pump.

[0025] Preferably, the demisting equipment is a wet electrostatic demisting equipment, which is composed of a high-voltage electrostatic device and an electric demisting device body.

[0026] Preferably, the demisting equipment is a wet electrostatic demisting equipment used to demist the exhaust gas, is electrically connected to a high-voltage power supply, and is controlled by an electric control cabinet.

[0027] Furthermore, a static pressure fan for transmission is provided between the discharge tower and the treatment pipeline, and the air inlet and discharge port of the static pressure fan are both connected to the treatment pipeline.

[0028] Furthermore, the alkaline washing water tank includes a water tank body, a cover plate, a filter plate and a baffle plate. A cover plate is provided on the top of the water tank body. A plurality of baffle plates are alternately provided inside the water tank body. A filter plate is provided at the reflux port of the water tank body.

[0029] Preferably, a cover plate is rotatably connected to the top of the water tank body, a plurality of baffles are alternately arranged at the inlet of the water tank body, and a filter plate is arranged at the reflux port of the water tank body.

[0030] A method for using a waste gas treatment system for treating aging and roasting, the method for using the waste gas treatment system comprising the following steps:

[0031] S1: Turn on the water pumps of the quenching water tank, the alkali washing water tank, the demisting water tank and the alkali water system to configure the alkali water. When the liquid in the water tank reaches the set maximum liquid level, the sodium hydroxide solution outlet valve of the first reaction tank will be closed, the valve of the alkali water system water supply pipeline will be closed, and then the centrifugal fan leading to the treatment pipeline will be turned on. The operating frequency of the centrifugal fan is automatically controlled according to the pressure feedback value of the pressure transmitter in the treatment pipeline, so that the pressure feedback value approaches the set value;

[0032] S2: Open the valve of the treatment pipeline to connect the waste gas with the treatment pipeline. When the waste gas passes through the quenching equipment, open the valve of the quenching equipment, and spray the alkaline water in the quenching water tank into the quenching equipment. The sprayed water evaporates quickly and absorbs heat, so that the waste gas temperature can be quickly reduced;

[0033] S3: When the waste gas passes through the alkali washing equipment, the valve of the alkali washing equipment is opened, and the alkaline water in the alkali washing water tank is sprayed into the alkali washing equipment. The waste gas is fully contacted with the sprayed alkaline water, and physical absorption or chemical reaction is carried out. The acidic waste gas molecules are removed through acid-base neutralization;

[0034] S4: When the exhaust gas passes through the defogger, the defogger is turned on, and when the flue gas containing water mist and other pollutants enters the defogger, it is captured; when the exhaust gas does not pass through the defogger, the defogger is turned off, and the alkaline water in the defogger water tank is started to spray the captured dust washing mist particles inside the defogger;

[0035] S5: When the waste gas detection device passes the test, open the channel valve between the emission tower and the treatment pipeline to allow the waste gas to flow to the quenching equipment, alkali washing equipment, demisting equipment, and emission tower in sequence for gas treatment and discharge.

[0036] A control method for a waste gas treatment system for treating aging and roasting, the control method for the waste gas treatment system comprising the following:

[0037] L1: When the liquid level of the quenching water tank is ≤0.7m, open the alkaline water system to fill the quenching water tank with alkaline water. When the water level reaches 1.0m, close the channel between the alkaline water system and the quenching water tank.

[0038] L2: When the liquid level of the quenching water tank is ≥1.3m, open the connection between the quenching water tank and the sewage pump; when the quenching water tank is drained to a liquid level of 1.0m, close the connection between the quenching water tank and the sewage pump;

[0039] L3: When the liquid level of the alkali washing water tank is ≤0.7m, open the alkali water system to fill the alkali washing water tank with alkali water. When the water is replenished to 1.0m, close the channel between the alkali water system and the alkali washing water tank.

[0040] L4: When the liquid level of the alkali washing water tank is ≥1.3m, open the connection between the alkali washing water tank and the sewage pump. When the alkali washing water tank is drained to a liquid level of 1.0m, close the connection between the alkali washing water tank and the sewage pump.

[0041] L5: When the liquid level of the quench water tank and the alkali washing water tank is ≤0.4m for more than 10 seconds, detection is required. When the liquid level is ≤0.4m for more than 60 seconds, the system needs to be shut down for full detection.

[0042] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0043] ① The quenching equipment uses the circulating liquid in the quenching water tank to act on the exhaust gas, effectively improving the VOCs treatment capacity;

[0044] The quenching equipment has ceramic saddle fillers. The spray system inside the tower body is a mesh system consisting of main pipes, branch pipes and nozzles. Each circulating pump corresponds to a spray layer. The spray liquid in the quenching water tank is transported to the nozzle by the circulating pump and evenly sprayed on the filler surface. Among them, the circulating pump flow part is made of corrosion-resistant materials to prevent the circulating liquid from corroding the pump head after absorbing the exhaust gas. The demisting device in the tower body is composed of baffles and dehydration fillers. The gas containing droplets in the tower body enters the demisting device, and the droplets are removed under the action of the baffles and dehydration fillers, effectively improving the VOCs treatment capacity;

[0045] ② The quenching water tank, alkali washing water tank and demisting water tank are equipped with electric valves for water replenishment and drug addition to achieve automatic control and linkage adjustment, which is convenient for on-site personnel to inspect and maintain;

[0046] The quenching water tank automatically opens the dosing electric valve to replenish the alkali solution in the quenching water tank according to the pH value feedback from the pH meter, and automatically opens the water replenishment electric valve to replenish the quenching water tank according to the liquid level feedback from the liquid level meter. The alkali solution replenishment amount is monitored by the flow meter. When the alkali solution usage exceeds the set value, the alkali solution replacement program is started in combination with the pH situation, that is, the drain electric valve is opened to drain the liquid. After draining to a low liquid level, the water replenishment electric valve and the dosing electric valve are opened to replenish water and dosing, which effectively improves the VOCs control capacity and is convenient for on-site personnel to inspect and maintain.

[0047] ③ The demisting equipment effectively improves the VOCs treatment capacity by capturing droplets and other pollutants in the exhaust gas;

[0048] The demisting equipment consists of a high-voltage electrostatic device and an electrostatic demister body. When working, the high-voltage electrostatic device applies negative high voltage electricity to the corona wire installed in the wet electrostatic demister to form an uneven high-voltage electrostatic field, thereby capturing droplets and other pollutants in the flue gas.

[0049] Since the droplets formed by the mixing of dust and water have good conductivity, they can collect sticky and high resistivity dust that electrostatic precipitators cannot collect.

[0050] There is no rapping device but a full-coverage device, so there is no secondary flying problem and no problem of transmission device being prone to failure;

[0051] It can provide corona power several times that of electrostatic precipitator, and has high demisting and dust removal efficiency, especially for fine dust particles, droplets, aerosols, metal particles, acid mist, etc. It has a strong capture ability.

[0052] ④ The first heat exchanger and the second heat exchanger of the heat exchange system are respectively heat exchanged with the water flowing into the alkali washing water tank and the quenching water tank, and the water flowing into the quenching water tank is cooled to form cold water, and low-temperature alkaline water is formed in the quenching water tank, which can improve the cooling efficiency of the quenching equipment; the water flowing into the alkali washing water tank is heated to form hot water, and slightly higher temperature alkaline water is formed in the alkali washing water tank. The warm water can improve the washing efficiency of the alkali washing tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is a schematic diagram of a waste gas treatment system for treating aging and roasting;

[0055] Figure 2 It is a schematic diagram of the connection and coordination between the quenching equipment and the alkaline water system;

[0056] Figure 3 It is a schematic diagram of the connection and coordination between the alkali washing equipment and the alkali water system;

[0057] Figure 4 This is a schematic diagram of the connection and coordination between the demisting equipment and the alkaline water system;

[0058] Figure 5 This is a cross-sectional view of the alkaline washing water tank.

[0059] in,

[0060] 1. Rapid cooling equipment;

[0061] 2. Alkaline washing equipment;

[0062] 3. Demisting equipment;

[0063] 4. Alkaline water system;

[0064] 5. Emission tower;

[0065] 6. Governance pipeline;

[0066] 7. Heat exchange system; 701. compressor; 702. first heat exchanger; 703. throttle valve; 704. second heat exchanger;

[0067] 8. Rapid cooling water tank;

[0068] 9. Alkali washing water tank; 901. Water tank body; 902. Cover plate; 903. Filter plate; 904. Baffle;

[0069] 10. Demisting water tank;

[0070] 11. Water supply electric valve;

[0071] 12. Dosing electric valve;

[0072] 13. pH tester;

[0073] 14. Liquid level gauge;

[0074] 15. Flow meter;

[0075] 16. First water pump;

[0076] 17. Second water pump;

[0077] 18. The third water pump;

[0078] 19. Float measuring device;

[0079] 20. Static pressure fan;

[0080] 21. Feedback circuit;

[0081] 22. Sewage pump. DETAILED DESCRIPTION

[0082] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the described embodiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0083] Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field to which this application belongs. "First", "second" and similar words used in this application do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0084] Example 1

[0085] like Figure 1-5 As shown, this embodiment discloses a waste gas treatment system for treating aging and roasting, comprising: a quenching device 1, an alkali washing device 2, a demisting device 3, an alkaline water system 4 and a discharge tower 5; the quenching device 1 is connected to the waste gas through a treatment pipeline 6, the alkali washing device 2 is connected to the quenching device 1 through the treatment pipeline 6, the demisting device 3 is connected to the alkali washing device 2 through the treatment pipeline 6, and the discharge tower 5 is connected to the demisting device 3 through the treatment pipeline 6, and a centrifugal fan and a pressure transmitter are provided on the treatment pipeline 6, and the pressure feedback value of the pressure transmitter automatically controls the working frequency of the centrifugal fan; an exhaust gas detection device is also provided between the discharge tower 5 and the treatment pipeline 6;

[0086] The alkaline water system 4 and the quenching equipment 1 are also connected to a quenching water tank 8 through a water pump, which is used to configure alkaline water to cool the exhaust gas and perform preliminary alkali washing;

[0087] The alkaline water system 4 and the alkaline washing equipment 2 are also connected to an alkaline washing water tank 9 through a water pump for preparing alkaline water to perform alkaline washing on the waste gas;

[0088] The alkaline water system 4 and the demisting device 3 are also connected to a demisting water tank 10 through a water pump, which is used to prepare alkaline water to clean the dust and fog particles inside the demisting device 3;

[0089] The quenching water tank 8 and the alkali washing water tank 9 are also connected to the wastewater discharge area through the sewage pump 22.

[0090] When the exhaust gas generated by the push plate kiln and the mixer is transported to the exhaust gas treatment system through the exhaust gas collection pipeline, a pressure transmitter is set on each of the six branch pipelines to monitor the pressure changes of the pipelines in real time. After being collected, it is transported to the inlet of the quenching equipment 1 through an exhaust gas main pipe;

[0091] When the system processing air volume is 16000Nm3 / h and the exhaust gas temperature is about 400℃, the exhaust gas first enters the quenching equipment 1 for rapid cooling and cooling treatment. The alkaline spray liquid is sprayed from the upper end of the interior of the quenching equipment 1 through a spiral nozzle. The exhaust gas enters from the lower inner part of the quenching equipment 1 and passes through the internal ceramic filler to contact the spray liquid in reverse. The ceramic filler can increase the contact area, so that the exhaust gas flowing through the quenching equipment 1 is fully in contact with the spray liquid, generating mass transfer and heat transfer. The water in the spray liquid evaporates quickly and absorbs heat, so that the exhaust gas temperature can be rapidly reduced to 80℃~100℃. In addition, this project uses alkaline solution as the spray liquid, and removes most of the acidic components in the exhaust gas through acid-base neutralization. At the same time, some water-soluble components and particulate matter in the exhaust gas are removed during the circulating spraying process;

[0092] The waste gas after preliminary cooling and washing enters the alkaline washing equipment 2 to remove the remaining acidic substances and water-soluble substances in the waste gas; the treated waste gas, because it will carry a certain amount of droplets, passes into the demisting equipment 3, and undergoes efficient demisting treatment to remove most of the water vapor in the gas to ensure that the sulfuric acid mist meets the standards. The treated gas that meets the standards is sucked by the static pressure fan 20 and led to high altitude discharge through the chimney of the emission tower 5.

[0093] As a specific implementation, it also includes a heat exchange system 7, which includes a compressor 701, a first heat exchanger 702, a throttle valve 703 and a second heat exchanger 704;

[0094] The first heat exchanger 702 is connected to the outlet of the compressor 701, the second heat exchanger 704 is connected to the first heat exchanger 702 through the throttle valve 703, and the second heat exchanger 704 is connected to the compressor 701;

[0095] The alkaline water system 4 is also connected to the quenching water tank 8 through the second heat exchanger 704 to provide low-temperature alkaline water to the quenching water tank 8;

[0096] The alkaline water system 4 is also connected to the alkaline washing water tank 9 through the first heat exchanger 702 to provide the alkaline washing water tank 9 with alkaline water at a slightly higher temperature.

[0097] Specifically, the compressor 701 compresses the refrigerant to form a high-temperature and high-pressure gas, and the high-temperature and high-pressure gaseous refrigerant flows into the first heat exchanger 702 for heat exchange and cooling, and then the gaseous refrigerant passes through the throttle valve 703 to reduce the pressure, and then enters the second heat exchanger 704 to absorb the heat of the external medium to become a liquid refrigerant, completing the refrigeration cycle;

[0098] The first heat exchanger 702 and the second heat exchanger 704 of the heat exchange system 7 respectively exchange heat with the water flowing into the alkali washing water tank 9 and the quenching water tank 8, and the water flowing into the quenching water tank 8 is cooled into cold water, and low-temperature alkaline water is formed in the quenching water tank 8, which can improve the cooling efficiency of the quenching equipment 1; the water flowing into the alkali washing water tank 9 is heated into hot water, and slightly higher temperature alkaline water is formed in the alkali washing water tank 9. The warm water can improve the washing efficiency of the alkali washing equipment 2.

[0099] As a specific implementation method, the quenching water tank 8 is connected to the alkaline water system 4 through a water replenishment electric valve 11 and a dosing electric valve 12. A pH detector 13 and a liquid level meter 14 for measuring alkaline water are provided in the quenching water tank 8. A flow meter 15 for measuring water flow is provided at the connection between the quenching water tank 8 and the alkaline water system 4. The quenching water tank 8 also provides alkaline water to the quenching equipment 1 through a first water pump 16 for cooling.

[0100] Specifically, the water replenishment and drug addition of the quenching water tank 8 are controlled by the water replenishment electric valve 11 and the drug addition electric valve 12, so as to realize automatic control and linkage adjustment, which is convenient for on-site personnel to inspect and maintain;

[0101] The quenching water tank 8 automatically opens the dosing electric valve 12 to replenish the alkali solution in the quenching water tank 8 according to the pH value feedback from the pH detector 13, and automatically opens the water replenishment electric valve 11 to replenish the quenching water tank 8 according to the liquid level feedback from the liquid level meter 14. The alkali solution replenishment amount is monitored by the flow meter 15. When the alkali solution usage exceeds the set value, the alkali solution replacement program is started in combination with the pH situation, that is, the drain electric valve is opened to drain the liquid. After draining to a low liquid level, the water replenishment electric valve 11 and the dosing electric valve 12 are opened to replenish water and dosing, which effectively improves the VOCs control capacity and is convenient for on-site personnel to inspect and maintain.

[0102] Specifically, when an abnormal temperature is detected at the outlet of the quenching equipment 1, an alarm signal is sent out through the control system, the cut-off valve of the treatment pipeline 6 is closed, and when the emergency bypass valve is opened, the high-temperature exhaust gas is discharged from the bypass valve to other places without passing through this system, thereby protecting the equipment and preventing accidents, and prompting the staff to check the cause;

[0103] Specifically, a water pump is arranged on each packing layer of the quenching equipment 1. When one water pump fails, the other water pump operates normally (its main function is to ensure the spraying effect of each layer. When a water pump fails, it can be used for a short emergency, and at the same time, an audible and visual alarm is sounded, and feedback is given to the central control. A temperature sensor is arranged in the tower. If the temperature exceeds the limit, the exhaust gas is bypassed.) This can prevent the temperature in the tower from being too high and damaging the tower body, and at the same time send out an alarm signal to remind the staff.

[0104] Specifically, an on-site pressure gauge is provided between the quenching equipment 1 and the treatment pipeline (6) to observe the pressure of the water outlet pipeline of the water pump, to prevent the outlet pressure from being too high and to prevent the water pump from running without water.

[0105] As a specific implementation method, a water replenishment electric valve 11 and a drug addition electric valve 12 are provided between the alkaline washing water tank 9 and the alkaline water system 4, a pH detector 13 and a liquid level meter 14 for measuring alkaline water are provided in the alkaline washing water tank 9, and a flow meter 15 for measuring water flow is provided at the connection between the alkaline washing water tank 9 and the alkaline water system 4; the alkaline washing water tank 9 also provides alkaline water to the quenching equipment 1 through a second water pump 17 for removing acidic gases.

[0106] Specifically, the alkaline washing water tank 9 is of the differential gas-water mixed contact countercurrent type. The filler in the alkaline water system 4 is the basic component for gas-liquid two-phase contact. When the waste gas enters the filler layer of the alkaline water system 4, there is liquid sprayed from the top on the filler layer, and a liquid film is formed on the filler. The gas flows through the filler layer, and the waste gas is fully in contact with the spraying liquid, and physical absorption or chemical reaction is carried out. The acidic waste gas molecules are removed through the acid-base neutralization effect, and the liquid on the liquid film flows into the alkaline washing water tank 9 at the bottom of the alkaline water system 4 under the action of gravity. The treated gas is defogged by a wire mesh demister and a baffle and then discharged from the equipment, so as to separate the pollutants in the gas and convert them into harmless substances to achieve the purpose of purifying the gas.

[0107] As a specific implementation, the demisting device 3 is a wet electrostatic demisting device, the dust collecting electrode of the demisting device 3 absorbs and collects the acidic smoke, and the demisting water tank 10 sprays and cleans the dust collecting electrode of the demisting device 3 through a nozzle;

[0108] A water replenishment electric valve 11 and a dosing electric valve 12 are provided between the demisting water tank 10 and the alkaline water system 4. A float measuring device 19 is provided in the demisting water tank 10. The demisting water tank 10 also provides alkaline water for cleaning to the demisting equipment 3 through a third water pump 18.

[0109] Specifically, the demisting device 3 is a wet electrostatic demisting device, which is composed of a high-voltage electrostatic device and an electric demisting device body. Its working principle is the same as that of the electrostatic demisting device, except that the precipitation electrode adopts a tube bundle structure, and each precipitation electrode tube corresponds to a cathode corona wire. When working, the high-voltage electrostatic device is used to apply negative high voltage electricity to the corona wire set up in the wet electrostatic demisting device, thereby forming an uneven high-voltage electrostatic field between the corona wire and the precipitation electrode tube, and the two electrodes are coaxially arranged, and the electric field strength of each point in the precipitation electrode tube is inversely proportional to the distance between the point and the corona wire. Under the action of the electric field force, a corona zone is formed inside the entire precipitation electrode tube, and in the corona zone, a high concentration of negative ions (electrons) continuously move from the corona electrode to the precipitation electrode tube to form a corona current. When flue gas containing water mist and other pollutants enters the precipitation electrode tube, the water mist and pollutants are charged due to the collision and diffusion of ions, and then quickly reach the inner wall of the precipitation electrode tube under the action of the electric field force and release the charge at the same time, forming a liquid film on the inner wall of the precipitation electrode tube. Under the action of gravity, the liquid film flows to the liquid collecting tank at the bottom of the electrostatic precipitator for centralized treatment, thereby achieving the purpose of capturing droplets and other pollutants in the flue gas.

[0110] The demisting process of the wet electrostatic demisting device can be summarized into the following four stages: ionization of gas, charging of dust and mist particles, sedimentation of charged dust and mist particles, and cleaning of collected dust.

[0111] Since the droplets formed by the mixing of dust and water have good conductivity, they can collect sticky and high resistivity dust that electrostatic precipitators cannot collect.

[0112] There is no rapping device but a full-coverage device, so there is no secondary flying problem and no problem of transmission device being prone to failure;

[0113] It can provide corona power several times that of electrostatic precipitator, and has high demisting and dust removal efficiency, especially for fine dust particles, droplets, aerosols, metal particles, acid mist, etc. It has a strong capture ability.

[0114] Specifically, the flue gas particles enter the high-voltage corona area and are charged. The ultra-fine flue gas is broken down by the high voltage to form negative ions, which then flow through the electrostatic field and are captured by electrostatic adsorption and collected at the dust collecting electrode 3 of the demisting equipment.

[0115] When a large amount of dust and mist is accumulated in the precipitation electrode of the demisting device 3, alkaline water is sprayed to the precipitation electrode through the alkaline washing water tank 9 to clean the dust and mist particles inside the precipitation electrode.

[0116] As a specific implementation manner, a static pressure fan 20 for transmission is further provided between the discharge tower 5 and the treatment pipeline 6 , and the air inlet and the discharge port of the static pressure fan 20 are both connected to the treatment pipeline 6 .

[0117] Specifically, the static pressure fan 20 can provide additional pressure (ie, static pressure), which can effectively overcome these resistances and ensure that the gas can be smoothly transmitted to other processing equipment even in a complex pipeline layout of the treatment pipeline 6.

[0118] Example 2

[0119] like Figure 1-5 As shown, this embodiment discloses a waste gas treatment system for treating aging and roasting, comprising: a quenching device 1, an alkali washing device 2, a demisting device 3, an alkaline water system 4 and a discharge tower 5; the quenching device 1 is connected to the waste gas through a treatment pipeline 6, the alkali washing device 2 is connected to the quenching device 1 through the treatment pipeline 6, the demisting device 3 is connected to the alkali washing device 2 through the treatment pipeline 6, and the discharge tower 5 is connected to the demisting device 3 through the treatment pipeline 6, and a centrifugal fan and a pressure transmitter are provided on the treatment pipeline 6, and the pressure feedback value of the pressure transmitter automatically controls the working frequency of the centrifugal fan; an exhaust gas detection device is also provided between the discharge tower 5 and the treatment pipeline 6;

[0120] The alkaline water system 4 and the quenching equipment 1 are also connected to a quenching water tank 8 through a water pump, which is used to configure alkaline water to cool the exhaust gas and perform preliminary alkali washing;

[0121] The alkaline water system 4 and the alkaline washing equipment 2 are also connected to an alkaline washing water tank 9 through a water pump for preparing alkaline water to perform alkaline washing on the waste gas;

[0122] The alkaline water system 4 and the demisting device 3 are also connected to a demisting water tank 10 through a water pump, which is used to prepare alkaline water to clean the dust and fog particles inside the demisting device 3;

[0123] The quenching water tank 8 and the alkali washing water tank 9 are also connected to the wastewater discharge area through the sewage pump 22. As a specific embodiment, the alkali washing water tank 9 includes a water tank body 901, a cover plate 902, a filter plate 903 and a baffle 904. The top of the water tank body 901 is provided with a cover plate 902, the inside of the water tank body 901 is provided with a plurality of baffles 904 alternately arranged, and the reflux port of the water tank body 901 is provided with a filter plate 903.

[0124] Specifically, the baffles 904 alternately arranged inside the tank can guide the water flow to form a smooth return flow. Such a design helps the solid particles in the water to settle during the flow. The filter plate 903 at the return port of the water tank body 901 filters out the fine particles or suspended matter brought back from the system, keeping the circulating water clean, thereby ensuring the filtering efficiency and cleaning effect;

[0125] However, when cleaning is required, the cover plate 902 on the top of the water tank body 901 can be rotated open and the solid particles inside the water tank body 901 can be manually cleaned, which can effectively extend the overall service life of the alkaline washing water tank 9.

[0126] Example 3

[0127] like Figure 1-5 As shown, this embodiment discloses a method for using a waste gas treatment system for treating aging and roasting, and the method for using the waste gas treatment system includes the following:

[0128] S1: Turn on the quenching water tank 8, the alkaline washing water tank 9, the demisting water tank 10 and the water pump of the alkaline water system 4 to configure the alkaline water. When the liquid in the water tank reaches the set maximum liquid level, the sodium hydroxide solution outlet valve of the first reaction tank will be closed, the valve of the water supply pipeline of the alkaline water system 4 will be closed, and then the centrifugal fan leading to the treatment pipeline 6 will be turned on. The operating frequency of the centrifugal fan is automatically controlled according to the pressure feedback value of the pressure transmitter in the treatment pipeline 6, so that the pressure feedback value approaches the set value;

[0129] S2: Open the valve of the treatment pipeline 6 to connect the waste gas with the treatment pipeline 6. When the waste gas passes through the quenching device 1, open the valve of the quenching device 1, and spray the alkaline water in the quenching water tank 8 into the interior of the quenching device 1. The sprayed water evaporates quickly and absorbs heat, so that the waste gas temperature can be quickly reduced;

[0130] S3: When the waste gas passes through the alkali washing device 2, the valve of the alkali washing device 2 is opened, and the alkaline water in the alkali washing water tank 9 is sprayed into the alkali washing device 2, and the waste gas is fully contacted with the sprayed alkaline water, and physical absorption or chemical reaction is performed, and the acidic waste gas molecules are removed through acid-base neutralization;

[0131] S4: When the exhaust gas passes through the defogger 3, the defogger 3 is turned on, and when the flue gas containing water mist and other pollutants enters the defogger 3, it is captured; when the exhaust gas does not pass through the defogger 3, the defogger 3 is turned off, and the alkaline water in the defogger water tank 10 is started to spray the captured dust washing mist particles into the defogger 3;

[0132] S5: When the waste gas detection device passes the test, open the channel valve between the discharge tower 5 and the treatment pipeline 6 to allow the waste gas to pass through the quenching equipment 1, the alkali washing equipment 2, the demisting equipment 3, and the discharge tower 5 for gas treatment and discharge.

[0133] Specifically, the static pressure fan 20 automatically adjusts the operating frequency according to the feedback of the pressure transmitter in the treatment pipeline 6, maintains the pressure in the pipeline at a set value, ensures that the entire exhaust gas treatment process is carried out in a stable air pressure environment, and improves the treatment efficiency and safety.

[0134] This embodiment also discloses a control method for a waste gas treatment system for treating aging and roasting, and the control method for the waste gas treatment system includes the following:

[0135] L1: When the liquid level of the quenching water tank 8 is ≤0.7m, the alkaline water system 4 is opened to inject alkaline water into the quenching water tank 8. When the water level reaches 1.0m, the channel between the alkaline water system 4 and the quenching water tank 8 is closed;

[0136] L2: When the liquid level of the quenching water tank 8 is ≥1.3m, the quenching water tank 8 is opened and connected to the sewage pump 22; when the quenching water tank 8 is drained to a liquid level of 1.0m, the quenching water tank 8 is closed and connected to the sewage pump 22;

[0137] L3: When the liquid level of the alkaline washing water tank 9 is ≤0.7m, the alkaline water system 4 is opened to inject alkaline water into the alkaline washing water tank 9. When the water is replenished to 1.0m, the channel between the alkaline water system 4 and the alkaline washing water tank 9 is closed;

[0138] L4: When the liquid level of the alkali washing water tank 9 is ≥1.3m, the alkali washing water tank 9 is opened and connected to the sewage pump 22. When the alkali washing water tank 9 is drained to a liquid level of 1.0m, the alkali washing water tank 9 is closed and connected to the sewage pump 22.

[0139] L5: When the liquid level value of the quench water tank 8 and the alkaline washing water tank 9 is ≤0.4m for more than 10 seconds, detection is required. When the liquid level value is ≤0.4m for more than 60 seconds, the system needs to be shut down for full detection.

[0140] Specifically, these liquid level control logics (L1 to L5) are designed to ensure the normal operation of the quench water tank 8 and the alkali washing water tank 9, while avoiding the risks of overflow and dry running (due to low tank liquid level, the minimum liquid level for pump operation cannot be reached).

[0141] How it works

[0142] When the exhaust gas generated by the push plate kiln and the mixer is transported to the exhaust gas treatment system through the exhaust gas collection pipeline, a pressure transmitter is set on each of the six branch pipelines to monitor the pressure changes of the pipelines in real time. After being collected, it is transported to the inlet of the quenching equipment 1 through an exhaust gas main pipe;

[0143] When the system processing air volume is 16000Nm3 / h and the exhaust gas temperature is about 400℃, the exhaust gas first enters the quenching equipment 1 for rapid cooling and cooling treatment. The alkaline spray liquid is sprayed from the upper end of the interior of the quenching equipment 1 through a spiral nozzle. The exhaust gas enters from the lower inner part of the quenching equipment 1 and passes through the internal ceramic filler to contact the spray liquid in reverse. The ceramic filler can increase the contact area, so that the exhaust gas flowing through the quenching equipment 1 is fully in contact with the spray liquid, generating mass transfer and heat transfer. The water in the spray liquid evaporates quickly and absorbs heat, so that the exhaust gas temperature can be rapidly reduced to 80℃~100℃. In addition, this project uses alkaline solution as the spray liquid, and removes most of the acidic components in the exhaust gas through acid-base neutralization. At the same time, some water-soluble components and particulate matter in the exhaust gas are removed during the circulating spraying process;

[0144] The waste gas after preliminary cooling and washing enters the alkaline washing equipment 2 to remove the remaining acidic substances and water-soluble substances in the waste gas; the treated waste gas, because it will carry a certain amount of droplets, passes into the demisting equipment 3, and undergoes efficient demisting treatment to remove most of the water vapor in the gas to ensure that the sulfuric acid mist meets the standards. The treated gas that meets the standards is sucked by the static pressure fan 20 and led to high altitude discharge through the chimney of the emission tower 5.

[0145] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. 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 embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A waste gas treatment system for treating aging and roasting, characterized in that: include: A quenching device (1), an alkali washing device (2), a demisting device (3), an alkali water system (4) and a discharge tower (5); the quenching device (1) is connected to the exhaust gas via a treatment pipeline (6), the alkali washing device (2) is connected to the quenching device (1) via a treatment pipeline (6), the demisting device (3) is connected to the alkali washing device (2) via a treatment pipeline (6), the discharge tower (5) is connected to the demisting device (3) via a treatment pipeline (6), a centrifugal fan and a pressure transmitter are provided on the treatment pipeline (6), and the pressure feedback value of the pressure transmitter automatically controls the working frequency of the centrifugal fan; an exhaust gas detection device is also provided between the discharge tower (5) and the treatment pipeline (6); The alkaline water system (4) and the quenching device (1) are also connected to a quenching water tank (8) via a water pump, which is used to prepare alkaline water to cool the waste gas and perform preliminary alkali washing; The alkaline water system (4) and the alkaline washing equipment (2) are also connected to an alkaline washing water tank (9) via a water pump for preparing alkaline water to perform alkaline washing on the waste gas; The alkaline water system (4) and the demisting device (3) are also connected to a demisting water tank (10) via a water pump, and is used to prepare alkaline water to clean dust and fog particles inside the demisting device (3); The quenching water tank (8) and the alkali washing water tank (9) are also connected to the wastewater discharge area via a sewage pump (22).

2. The exhaust gas treatment system for treating aging and roasting according to claim 1 is characterized in that: The invention also comprises a heat exchange system (7), wherein the heat exchange system (7) comprises a compressor (701), a first heat exchanger (702), a throttle valve (703) and a second heat exchanger (704); The first heat exchanger (702) is connected to the outlet of the compressor (701), the second heat exchanger (704) is connected to the first heat exchanger (702) via a throttle valve (703), and the second heat exchanger (704) is connected to the compressor (701); The alkaline water system (4) is also connected to the quenching water tank (8) via the second heat exchanger (704) to provide low-temperature alkaline water to the quenching water tank (8); The alkaline water system (4) is also connected to the alkaline washing water tank (9) via the first heat exchanger (702) to provide the alkaline washing water tank (9) with alkaline water at a slightly higher temperature.

3. The exhaust gas treatment system for treating aging and roasting according to claim 1 is characterized in that: The demisting device (3) is an electrostatic smoke removal device. The dust collecting electrode of the demisting device (3) absorbs and collects the acid smoke. The demisting water tank (10) sprays and cleans the dust collecting electrode of the demisting device (3) through a nozzle.

4. The waste gas treatment system for treating aging and roasting according to claim 1 is characterized in that: The quenching water tank (8) is connected to the alkaline water system (4) via a water replenishment electric valve (11) and a dosing electric valve (12); a pH detector (13) and a liquid level meter (14) for measuring alkaline water are provided in the quenching water tank (8); a flow meter (15) for measuring water flow is provided at the connection between the quenching water tank (8) and the alkaline water system (4); the quenching water tank (8) also provides alkaline water for cooling the quenching device (1) via a first water pump (16).

5. The waste gas treatment system for treating aging and roasting according to claim 1 is characterized in that: A water replenishment electric valve (11) and a drug addition electric valve (12) are provided between the alkaline washing water tank (9) and the alkaline water system (4); a pH detector (13) and a liquid level meter (14) for measuring alkaline water are provided in the alkaline washing water tank (9); a flow meter (15) for measuring water flow is provided at the connection between the alkaline washing water tank (9) and the alkaline water system (4); the alkaline washing water tank (9) also provides alkaline water for the quenching device (1) through a second water pump (17) for removing acidic gases.

6. The waste gas treatment system for treating aging and roasting according to claim 1, characterized in that: A water replenishment electric valve (11) and a drug addition electric valve (12) are provided between the demisting water tank (10) and the alkaline water system (4); a floating ball measuring device (19) is provided in the demisting water tank (10); and the demisting water tank (10) also provides alkaline water for cleaning to the demisting equipment (3) through a third water pump (18).

7. The waste gas treatment system for treating aging and roasting according to claim 1 is characterized in that: A static pressure fan (20) for transmission is also provided between the discharge tower (5) and the treatment pipeline (6), and the air inlet and discharge port of the static pressure fan (20) are both connected to the treatment pipeline (6).

8. The waste gas treatment system for treating aging and roasting according to claim 1, characterized in that: The alkaline washing water tank (9) comprises a water tank body (901), a cover plate (902), a filter plate (903) and a baffle plate (904); the top of the water tank body (901) is provided with a cover plate (902); a plurality of baffle plates (904) are alternately provided inside the water tank body (901); and the filter plate (903) is provided at the reflux port of the water tank body (901).

9. A method for using the waste gas treatment system for treating aging and roasting according to any one of claims 1 to 8, characterized in that: The method of using the exhaust gas treatment system includes the following: S1: Turn on the water pumps of the quenching water tank (8), the alkaline washing water tank (9), the demisting water tank (10) and the alkaline water system (4) to prepare alkaline water. When the liquid in the water tank reaches the set maximum liquid level, the sodium hydroxide solution outlet valve of the first reaction tank will be closed, the valve of the water supply pipeline of the alkaline water system (4) will be closed, and then the centrifugal fan leading to the treatment pipeline (6) will be turned on. The operating frequency of the centrifugal fan is automatically controlled according to the pressure feedback value of the pressure transmitter in the treatment pipeline (6), so that the pressure feedback value approaches the set value; S2: Open the valve of the treatment pipeline (6) to connect the waste gas with the treatment pipeline (6). When the waste gas passes through the quenching device (1), open the valve of the quenching device (1) to spray the alkaline water in the quenching water tank (8) into the interior of the quenching device (1). The sprayed water evaporates quickly and absorbs heat, so that the waste gas temperature can be quickly reduced. S3: When the waste gas passes through the alkali washing device (2), the valve of the alkali washing device (2) is opened, and the alkaline water in the alkali washing water tank (9) is sprayed into the alkali washing device (2), so that the waste gas is fully contacted with the sprayed alkaline water, and physical absorption or chemical reaction is carried out, and the acidic waste gas molecules are removed through acid-base neutralization; S4: when the exhaust gas passes through the demisting device (3), the demisting device (3) is turned on, and when the smoke containing water mist and other pollutants enters the demisting device (3), it is captured; when the exhaust gas does not pass through the demisting device (3), the demisting device (3) is turned off, and the alkaline water in the demisting water tank (10) is started to spray the inside of the demisting device (3) to clean the captured dust and mist particles; S5: When the waste gas detection device passes the test, the channel valve between the discharge tower (5) and the treatment pipeline (6) is opened to allow the waste gas to flow to the quenching equipment (1), the alkali washing equipment (2), the demisting equipment (3), and the discharge tower (5) in sequence for gas treatment and discharge.

10. A control method for a waste gas treatment system for treating aging and roasting according to any one of claims 1 to 8, characterized in that: The control method of the exhaust gas treatment system includes the following: L1: When the liquid level of the quenching water tank (8) is ≤0.7m, the alkaline water system (4) is opened to inject alkaline water into the quenching water tank (8). When the water level reaches 1.0m, the passage between the alkaline water system (4) and the quenching water tank (8) is closed; L2: When the liquid level of the quenching water tank (8) is ≥1.3 m, the quenching water tank (8) is opened to connect with the sewage pump (22); when the quenching water tank (8) is drained to a liquid level of 1.0 m, the quenching water tank (8) is closed to connect with the sewage pump (22); L3: When the liquid level of the alkali washing water tank (9) is ≤0.7m, the alkali water system (4) is opened to inject alkali water into the alkali washing water tank (9). When the water level reaches 1.0m, the passage between the alkali water system (4) and the alkali washing water tank (9) is closed; L4: When the liquid level of the alkali washing water tank (9) is ≥1.3m, the alkali washing water tank (9) is opened to connect with the sewage pump (22); when the alkali washing water tank (9) is drained to a liquid level of 1.0m, the alkali washing water tank (9) is closed to connect with the sewage pump (22); L5: When the liquid level value of the quench water tank (8) and the alkali washing water tank (9) is ≤0.4m for a duration greater than 10 seconds, detection is required. When the liquid level value is ≤0.4m for a duration greater than 60 seconds, the system needs to be shut down for full detection.

Images