A VOCs treatment system with a desorption function and a use method

Abstract

The present application relates to the field of waste gas treatment, and discloses a VOCs treatment system with desorption function and a use method, two groups of molecular sieve adsorption equipment containing macroporous resins are connected with alkali washing equipment, after the waste gas is pretreated by the alkali washing equipment, the waste gas enters one group of the molecular sieve adsorption equipment, VOCs and other organic gases in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption equipment, and the gas after adsorption treatment reaches the standard is discharged at high altitude through an exhaust tower; when the macroporous resin of one group of the molecular sieve adsorption equipment is saturated, the waste gas discharged from the alkali washing equipment is introduced into the other group of the molecular sieve adsorption equipment to adsorb organic gases, the molecular sieve adsorption equipment saturated with adsorption is connected with a drying equipment and a cooling equipment, water vapor is introduced to carry out desorption regeneration, the macroporous resin after desorption is dried by hot air and then cooled, and then enters the adsorption process again, and the circulation is carried out in sequence, so that the emission waste gas reaches the standard.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment, specifically to a VOCs treatment system with desorption function and its usage method. Background Technology

[0002] my country emits more than 20 million tons of volatile organic compounds (VOCs) annually, which can cause serious air pollution. The domestic VOCs environmental protection industry has been developing for many years, but the overall progress is slow. One of the major obstacles is that the recovered solvents are often accompanied by deterioration phenomena such as acidification, discoloration, foul odor, and high water content. The existing organic solvent recovery and treatment methods and equipment have very low treatment yields and are not economically viable.

[0003] Many industrial processes, including production, wastewater treatment, and waste disposal, generate large amounts of waste gas containing volatile organic compounds (VOCs). In the production and processing of chemicals, pharmaceuticals, coatings, semiconductors, and printing industries, the evaporation of organic solvents produces significant amounts of volatile organic compounds, or VOCs, in waste gas. If VOCs are directly released into the atmosphere, they will not only severely pollute the air, but their molecules will also react with sunlight and ozone to form harmful organic particles, further damaging the atmosphere and having a very adverse impact on the environment and human health. Therefore, VOCs generated in industrial production must be treated before being released into the atmosphere to protect the environment and human health.

[0004] Currently, the most widely adopted and technologically mature method in my country is adsorption. This involves first pre-treating VOCs waste gas to remove dust particles, then passing it through an adsorption bed to adsorb organic matter, resulting in clean waste gas that is directly discharged. Once the adsorption capacity of the adsorption bed reaches saturation, it must undergo desorption and regeneration. Otherwise, the original adsorption layer will be unable to continue adsorbing VOCs molecules from the waste gas, thus losing its gas purification function. Therefore, the process of treating VOCs waste gas using adsorption methods requires continuous switching between adsorption and desorption modes.

[0005] To address the issue of VOCs waste gas treatment through adsorption and desorption, the industry has conducted relevant research and design. In the adsorption state, the first and second adsorption valves are open while the first and second desorption valves are closed. Waste gas enters the pretreatment tank through the waste gas inlet. After being filtered and dust-removed by the filter element, the gas enters the adsorption cylinder through the first vent. The organic matter in the gas is adsorbed by the adsorption layer and then passes through the second vent into the deodorization pipe. After being deodorized by the deodorization element, it is discharged from the clean gas outlet. In the desorption state, the first and second desorption valves are open while the first and second adsorption valves are closed. Desorption hot air enters the desorption inlet pipe from the desorption inlet and then enters the isolation cylinder through the third vent, causing the organic matter to detach from the adsorption layer. The desorption hot air carrying the organic matter enters the desorption outlet pipe through the fourth vent and then enters the burner for combustion. The VOCs molecules are burned into carbon dioxide and water vapor.

[0006] However, in the aforementioned prior art, when "macroporous resin" is used as the material of the adsorption tower, after long-term desorption of high-temperature gas, moisture may accumulate inside the macroporous resin. The moisture occupies the pores inside the resin, reducing the effective adsorption space and thus reducing the adsorption capacity for VOCs. Summary of the Invention

[0007] To overcome the technical problems existing in the prior art, the present invention is a VOCs treatment system with desorption function;

[0008] Another objective of this invention is to provide a method for using a VOCs treatment system with desorption function.

[0009] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0010] A VOCs treatment system with desorption function includes: an alkaline washing device, a drying device, several molecular sieve adsorption devices, a cooling device, and an exhaust tower; the alkaline washing device is connected to several molecular sieve adsorption devices through pipelines, and the several molecular sieve adsorption devices are connected to the exhaust tower through pipelines.

[0011] Several molecular sieve adsorption devices are also equipped with a first circulation pipe and a second circulation pipe; the first circulation pipe is equipped with a drying device for rapidly drying the molecular sieve adsorption devices; the second circulation pipe is equipped with a cooling device for cooling the molecular sieve adsorption devices.

[0012] Several molecular sieve adsorption devices are also connected to high-temperature steam via steam pipelines for high-temperature desorption.

[0013] Furthermore, the alkaline washing equipment includes an alkaline washing tower, an alkaline washing tank, an alkaline washing heating device, a spray water pump, and spray nozzles;

[0014] The bottom of the alkaline washing tower is connected to the alkaline washing tank, which is equipped with an alkaline washing heating device; the spray water pump is connected to the top of the alkaline washing tower through a spray pipe, and sprays chemical agents evenly into the alkaline washing tower through spray nozzles.

[0015] Specifically, the waste gas first undergoes alkaline washing, then is cooled by a condenser before entering the molecular sieve adsorption equipment. Furthermore, the alkaline washing tank is equipped with a floating ball valve to maintain the water level in the tank. The alkaline washing tank is connected to a chemical alkaline solution via an alkaline liquid control valve. The alkaline washing tank also contains a pH sensor, which is electrically connected to the alkaline liquid control valve to maintain the total amount of alkaline solution inside the tank.

[0016] Furthermore, the cooling device includes a first cooling component and a second cooling component. The first cooling component is connected to several molecular sieve adsorption devices through pipes. The second cooling component is connected to the first cooling component through a second circulation pipe. The drying device is connected to the second cooling component through the first circulation pipe.

[0017] Furthermore, the first cooling component includes a first condenser, a heat exchanger, a brine storage tank, and a brine tank pump;

[0018] The first condenser is connected to a heat exchanger, a brine storage tank, and a brine tank pump via heat exchange pipes; the heat exchanger is also connected to a low-temperature brine pipe to maintain the temperature of the brine in the heat exchange pipes.

[0019] Furthermore, the second cooling component includes a second condenser and a gate valve; the second condenser is connected to the first cooling component through a second circulation pipe, and the second condenser is also connected to low-temperature cooling water for reducing the gas temperature in the second circulation pipe; the second condenser is also provided with a condensate drain pipe, and a gate valve is provided on the condensate drain pipe.

[0020] Preferably, the second condenser is connected to the first condenser via a second circulation pipe.

[0021] Preferably, the first condenser is also provided with a condensate drain pipe, and the condensate drain pipe is equipped with a gate valve.

[0022] Furthermore, the drying equipment includes a fan and a heat exchanger, the fan being connected to the heat exchanger and providing a power source for the first circulation pipe; the heat exchanger is also connected to a steam pipe for heating the air.

[0023] Furthermore, the molecular sieve adsorption devices are divided into two groups, with each group of molecular sieve adsorption devices connected to the alkaline washing equipment and to the steam pipeline via a solenoid valve.

[0024] Preferably, the molecular sieve adsorption devices are divided into two groups. Each group of molecular sieve adsorption devices is connected to an alkaline washing device and a steam pipe via a solenoid valve. By opening the valve of one group of molecular sieve adsorption devices to connect with the alkaline washing device, waste gas is adsorbed. By opening the valve of another group of molecular sieve adsorption devices to connect with the steam pipe, organic gases in the resin are desorbed at high temperature.

[0025] Furthermore, a molecular sieve adsorption device includes two interconnected macroporous resin adsorption fixed beds, and water nozzles are connected to the macroporous resin adsorption fixed beds via solenoid valves.

[0026] A method of using a VOCs treatment system with desorption function, the method of using the VOCs treatment system includes the following:

[0027] S1: After being collected by the collection system, the organic waste gas first enters the alkaline washing equipment to remove acidic and water-soluble gases from the waste gas. Then the waste gas enters the cooling equipment. Relying on the property that the organic waste gas and other gases have different saturated vapor pressures at different temperatures, the temperature is lowered to separate some of the organic waste gas into liquid state.

[0028] S2: The condensed waste gas enters the molecular sieve adsorption equipment for adsorption. The VOCs in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption equipment. The gas that meets the adsorption standards is discharged into the atmosphere through the chimney of the exhaust tower.

[0029] S3: When the macroporous resin in the molecular sieve adsorption equipment reaches saturation, the desorption process is carried out. The inlet and outlet of the adsorption waste gas of the molecular sieve adsorption equipment are closed, the steam pipe is opened, and high-temperature water steam is introduced to desorb the organic gas in the macroporous resin. Then, most of the steam of the mixed organic gas enters the cooling equipment for cooling and liquefaction. The liquefied wastewater in the cooling equipment is discharged from the pipe.

[0030] S4: After the molecular sieve adsorption equipment has completed desorption, stop the steam supply, start the drying equipment to reduce the humidity inside the molecular sieve adsorption equipment and circulate it in the first circulation pipe. Then turn on the cooling equipment to condense and discharge the water molecules circulating inside the molecular sieve adsorption equipment, so that the molecular sieve adsorption equipment can be dried quickly.

[0031] S5: After the molecular sieve adsorption equipment has finished drying, turn off the drying equipment and use the cooling capacity of the cooling equipment and the internal circulation to cool the system, thereby cooling the adsorption material.

[0032] S6: Several molecular sieve adsorption devices are divided into two groups. One group of molecular sieve adsorption devices performs the adsorption process, and the other group performs the desorption process. Several molecular sieve adsorption devices are used in a "one adsorption and one desorption" cycle to ensure that the treated waste gas meets the standards stably.

[0033] Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

[0034] ① Install several molecular sieve adsorption devices and connect them to the chemical scrubbing tower to effectively improve VOCs treatment capacity;

[0035] Because the molecular sieve adsorption equipment is equipped with macroporous resin packing, when the exhaust gas comes into contact with the macroporous resin packing, the pores of the macroporous resin can effectively capture small molecule organic substances and other volatile components in the exhaust gas, such as odorous gases like dichloroethane, achieving a highly efficient adsorption and purification effect, thereby maintaining air quality.

[0036] ② Connect several molecular sieve adsorption devices to high-temperature steam through steam pipes to achieve high-temperature desorption;

[0037] When the macroporous resin of the molecular sieve adsorption equipment is saturated, the inlet and outlet valves of the adsorption waste gas of the molecular sieve adsorption equipment are closed, and high-temperature steam is introduced. When the high-temperature steam passes through the molecular sieve adsorption equipment, the activity of organic molecules adsorbed on the macroporous resin is enhanced, making it easier to desorb organic gases such as dichloroethane from the resin surface, thereby achieving desorption treatment. This significantly shortens the regeneration cycle of the molecular sieve adsorption equipment, thereby improving the treatment capacity and continuous operation capability of the VOCs treatment system.

[0038] ③ Connect the drying equipment to the molecular sieve adsorption equipment to achieve rapid drying;

[0039] After desorption is completed, stop the steam supply, turn on the fan and heat exchanger of the drying equipment to provide the necessary heat energy, accelerate the evaporation of surface moisture of the macroporous resin inside the molecular sieve adsorption equipment, dry the macroporous resin inside the molecular sieve adsorption equipment, and circulate it in the first circulation pipe to remove it, thus achieving the purpose of rapid drying.

[0040] ④ A portion of the cooling equipment is placed between the drying equipment and the molecular sieve adsorption equipment to achieve rapid moisture removal;

[0041] The drying equipment is connected to the second cooling component of the cooling equipment through the first circulation pipe. When the circulating hot air in the first circulation pipe evaporates the moisture, the second cooling component of the cooling equipment is turned on. The low-temperature cooling water of the second condenser exchanges heat with the circulating hot air, which rapidly reduces the temperature of the gas, thereby condensing the moisture and removing it through the condensate drain pipe. This allows for continuous and efficient removal of moisture.

[0042] When high-temperature steam is introduced into the molecular sieve adsorption equipment, organic gases are desorbed from the resin surface and mixed with the high-temperature steam to form high-temperature organic gases. At this time, the second cooling component of the cooling equipment is turned on. The low-temperature cooling water of the second condenser exchanges heat with the steam containing VOCs, which rapidly reduces the temperature of the high-temperature organic mixture. The water containing the mixed organic matter is condensed and removed through the condensate drain pipe, preparing it for discharge into the environment. This allows for continuous and efficient removal of water containing the mixed organic matter.

[0043] ⑤ The cooling equipment is equipped with multiple sets of condensers, thereby achieving the separation of organic waste gas from other gases at different temperatures;

[0044] During desorption, the property that different gases have different saturated vapor pressures at different temperatures is utilized. The first and second condensers are turned on. The organic waste gas is initially cooled to about 40 degrees Celsius in the first condenser and then cooled to 5 degrees Celsius in the second condenser. By reducing the temperature to 5 degrees Celsius, some of the organic waste gas in the waste gas is converted into liquid and separated. Different groups of condensers can work under progressive temperature gradients. Each stage is used to condense and separate components within a specific temperature range, which can remove organic waste gas more thoroughly.

[0045] However, some organic waste gas remains in the treated gas mixture, which needs to be further treated in a macroporous resin adsorption fixed bed. Attached Figure Description

[0046] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram of a VOCs treatment system with desorption function;

[0048] Figure 2 A schematic diagram of the connection and assembly of the alkaline washing equipment;

[0049] Figure 3 A schematic diagram of the connection and fit of the cooling equipment;

[0050] Figure 4 This is a schematic diagram of the connection and fit of the first circulation pipeline;

[0051] Figure 5 This is a schematic diagram of the connection and fit of the second circulation pipeline;

[0052] Figure 6 This is a schematic diagram of the connection and assembly of a molecular sieve adsorption device.

[0053] in,

[0054] 1. Alkali washing equipment; 101. Alkali washing tower; 102. Alkali washing tank; 103. Alkali washing heating equipment; 104. Spray water pump; 105. Spray nozzle; 106. Spray pipe; 107. Floating ball valve; 108. Alkali liquid control valve;

[0055] 2. Drying equipment; 201. Fan; 202. Heat exchanger;

[0056] 3. Molecular sieve adsorption equipment; 301. Adsorption fixed bed; 302. Macroporous resin packing;

[0057] 4. Cooling equipment; 401. First condenser; 402. Heat exchanger; 403. Brine storage tank; 404. Brine tank pump; 405. Second condenser; 406. Gate valve;

[0058] 5. Exhaust tower;

[0059] 6. First circulation pipeline;

[0060] 7. Second circulation pipeline;

[0061] 8. Heat exchange piping;

[0062] 9. Low-temperature brine pipeline;

[0063] 10. Steam pipes;

[0064] 11. Water spray head;

[0065] 12. Fresh water pipes. Detailed Implementation

[0066] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this application. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the described embodiments without creative effort are within the scope of protection of this application.

[0067] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0068] Example 1

[0069] like Figure 1-6 As shown, this embodiment discloses a VOCs treatment system with desorption function, including: an alkaline washing device 1, a drying device 2, a plurality of molecular sieve adsorption devices 3, a cooling device 4, and an exhaust tower 5; the alkaline washing device 1 is connected to the plurality of molecular sieve adsorption devices 3 through pipes, and the plurality of molecular sieve adsorption devices 3 are connected to the exhaust tower 5 through pipes.

[0070] Several molecular sieve adsorption devices 3 are also equipped with a first circulation pipe 6 and a second circulation pipe 7; the first circulation pipe 6 is equipped with a drying device 2 for rapidly drying the molecular sieve adsorption devices 3; the second circulation pipe 7 is equipped with a cooling device 4 for cooling the molecular sieve adsorption devices 3.

[0071] Several molecular sieve adsorption devices 3 are also connected to high-temperature steam through steam pipes 10 for high-temperature desorption.

[0072] Because the emissions of waste gas containing organic matter are continuously emitted during the production period, they need to be continuously adsorbed and treated.

[0073] Two sets of molecular sieve adsorption devices 3 containing macroporous resin are connected to the alkaline washing device 1. After the alkaline washing device 1 pre-treats the waste gas, it enters one of the molecular sieve adsorption devices 3. The VOCs and other organic gases in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption device 3. The gas after adsorption treatment meets the standards is discharged at high altitude through the exhaust tower 5.

[0074] When the macroporous resin of a set of molecular sieve adsorption devices 3 is saturated, the waste gas from the condenser 401 is passed into another set of molecular sieve adsorption devices 3 for adsorption and collection of organic gases. The saturated molecular sieve adsorption devices 3 are connected to the drying device 2 and the cooling device 4, and water vapor is introduced for desorption and regeneration. The desorbed macroporous resin is then dried and cooled by hot air before entering the adsorption process again. This cycle is repeated to ensure that the exhaust gas meets the standards.

[0075] Specifically, a condenser is installed between the alkaline washing equipment 1 and the molecular sieve adsorption equipment 3. After the waste gas is washed by the alkaline washing equipment 1, it is cooled by the condenser before entering the molecular sieve adsorption equipment 3.

[0076] Specifically, the molecular sieve adsorption device 3 is equipped with macroporous resin packing 302. When the exhaust gas comes into contact with the macroporous resin packing 302, the pores of the macroporous resin can effectively capture small molecule organic substances and other volatile components in the exhaust gas, such as VOCs gases like dichloroethane, to achieve a highly efficient adsorption and purification effect, thereby maintaining air quality.

[0077] Specifically, when the macroporous resin of the molecular sieve adsorption device 3 is saturated, the inlet and outlet valves of the adsorption waste gas of the molecular sieve adsorption device 3 are closed, and high-temperature steam is introduced. When the high-temperature steam passes through the molecular sieve adsorption device, the activity of the organic molecules adsorbed on the macroporous resin is enhanced, and the organic gas is desorbed from the resin surface to achieve desorption treatment. The steam is mixed and enters the cooling device 4, where most of the organic steam is liquefied into condensate and discharged through the cooling device 4. After desorption is completed, it is ready to enter again for adsorption.

[0078] This significantly shortens the regeneration cycle of molecular sieve adsorption equipment, thereby improving the treatment capacity and continuous operation capability of the VOCs treatment system.

[0079] As one specific implementation, the alkaline washing equipment 1 includes an alkaline washing tower 101, an alkaline washing tank 102, an alkaline washing heating device 103, a spray water pump 104, and a spray nozzle 105.

[0080] The bottom of the alkaline washing tower 101 is connected to the alkaline washing tank 102, and the alkaline washing tank 102 is equipped with an alkaline washing heating device 103; the spray water pump 104 is connected to the top of the alkaline washing tower 101 through the spray pipe 106, and sprays chemical agents evenly into the alkaline washing tower 101 through the spray nozzle 105.

[0081] The alkaline washing tank 102 is also equipped with a floating ball valve 107 for maintaining the water tank level. The alkaline washing tank 102 is connected to the chemical alkaline solution through the alkaline liquid control valve 108. The alkaline washing tank (102) is also equipped with a pH sensor. The alkaline liquid control valve 108 is electrically connected to the pH sensor to maintain the total amount of alkaline solution inside the alkaline washing tank 102.

[0082] Specifically, the alkali washing tower 101 has a diameter of 400mm-600mm; it can meet the capacity requirements of specific chemical reactions and ensure a sufficiently large contact area during the treatment process.

[0083] Specifically, the solubility of the gas can be increased by increasing the pressure inside the alkali scrubbing tower 101, making the absorption process of acidic gas in the alkali solution more rapid and effective, thereby improving the purification efficiency, and also helping to shorten the processing time and increase production capacity.

[0084] Specifically, since long-term operation can lead to the accumulation of impurities in the alkaline solution, the alkaline washing tank 102 can also intermittently discharge the alkaline solution, thereby periodically discharging the alkaline solution containing impurities, maintaining the effective concentration and cleanliness of the alkaline solution in the alkaline washing tank 102, and ensuring the washing effect.

[0085] Specifically, the alkaline washing heating equipment 103 has temperature measurement and heating functions.

[0086] Specifically, the chemical alkaline solution in the alkaline washing tank 102 is transmitted into the spray pipe 106 through the spray pump 104, and is evenly sprayed onto the top of the packing material in the alkaline washing tower 101 through the spray nozzles 105. When the exhaust gas enters the alkaline washing tower 101, the packing material in the washing tower 101 can increase the contact area between the alkaline solution and the exhaust gas, so as to make initial contact and react to remove acidic gases such as hydrogen chloride. At the same time, the sprayed alkaline solution can wash away the attached substances on the biological packing material.

[0087] Specifically, the alkaline washing heating equipment 103 can be turned on to increase the temperature of the alkaline solution in the alkaline washing tank 102, thereby accelerating the chemical reaction rate between the alkaline solution and the waste gas in the packing material. This is especially effective for some pollutants that react slowly at low temperatures. Temperature regulation helps maintain the stability of the waste gas treatment capacity in the system and can also perform intelligent temperature control in advance to prevent the alkaline solution from freezing.

[0088] When a portion of the chemical alkali solution in the alkaline washing tank 102 reacts or evaporates, the liquid level on the tank wall drops, causing the floating ball valve 107 to descend horizontally. The floating ball valve 107 will then automatically replenish water to the set height. When the pH value in the alkaline washing tank 102 decreases, the alkaline liquid control valve 108 opens, increasing its opening degree and thus automatically replenishing the alkaline solution. The electrical connection between the pH sensor and the alkaline liquid control valve 108 constitutes an automatic control system that can automatically replenish or adjust the amount of alkaline solution based on changes in the pH value of the alkaline solution in the alkaline washing tank 102. This avoids oversights in manual monitoring and ensures the continuity and reliability of the treatment process.

[0089] The design of the alkaline washing equipment 1 combines an innovative structure with highly controlled operations, greatly improving gas-liquid mass transfer efficiency within a limited space, and can also automatically replenish the amount of alkaline solution, making it more intelligent and efficient than traditional designs.

[0090] In alkaline washing applications, the alkaline solution must maintain a certain alkalinity. Specifically, when the pH of the alkaline solution in the alkaline washing tank 102 is less than 12, the alkaline solution needs to be replenished by controlling the floating ball valve 107 and the alkaline solution control valve 108. As a specific implementation, the drying equipment 2 includes a fan 201 and a heat exchanger 202. The fan 201 is connected to the heat exchanger 202 and provides a power source for the first circulation pipe 6. The heat exchanger 202 is also connected to the steam pipe 10 to heat the air.

[0091] Specifically, after desorption is completed, the steam supply is stopped, and the blower 201 and heat exchanger 202 of the drying equipment 2 are turned on to provide flowing hot air in the first circulation pipe 6, thereby accelerating the evaporation of surface moisture of the macroporous resin inside the molecular sieve adsorption equipment 3, drying the macroporous resin inside the molecular sieve adsorption equipment 3, and circulating it in the first circulation pipe to remove moisture, thus achieving the purpose of rapid drying.

[0092] Specifically, when high-temperature steam needs to be introduced for desorption treatment, the temperature of the steam is too low. The heat exchanger 202 can be turned on and connected to the steam pipe 10. When the steam passes through, it is heated to carry out high-temperature desorption and regeneration. After desorption, the steam pipe 10 is turned off so that the macroporous resin is dried and cooled by hot air before entering the adsorption process. This cycle is repeated to ensure that the treated waste gas emissions meet the standards.

[0093] In one specific implementation, several molecular sieve adsorption devices 3 are divided into two groups, with each group of molecular sieve adsorption devices connected to an alkaline washing device and to a steam pipeline via a solenoid valve.

[0094] A molecular sieve adsorption device 3 includes two interconnected macroporous resin adsorption fixed beds 301, and a water spray head 11 is also connected inside the macroporous resin adsorption fixed bed 301.

[0095] Specifically, the macroporous resin adsorption fixed bed 301 is connected to a water nozzle 11 via a fresh water pipe 12, which is used to rinse impurities on the surface of the adsorption bed, help decompose the adsorbed organic matter, and improve the regeneration efficiency and service life of the resin.

[0096] Specifically, when the macroporous resin of one set of molecular sieve adsorption equipment 3 is saturated, the waste gas from the alkaline washing equipment 1 is passed into another set of molecular sieve adsorption equipment 3 for adsorption and collection of organic gases. The saturated molecular sieve adsorption equipment 3 is then connected to the drying equipment 2 and the cooling equipment 4, and water vapor is introduced for desorption and regeneration. The desorbed macroporous resin is then dried and cooled by hot air before entering the adsorption process again. This cycle is repeated, so that the two sets of molecular sieve adsorption equipment 3 adopt a "one adsorption and one desorption" mode in sequence, so that the adsorption method for treating VOCs and other organic waste gases continuously switches between adsorption and desorption modes to ensure continuous treatment.

[0097] Example 2

[0098] like Figure 1-6 As shown, this embodiment discloses a VOCs treatment system with desorption function, including: an alkaline washing device 1, a drying device 2, a plurality of molecular sieve adsorption devices 3, a cooling device 4, and an exhaust tower 5; the alkaline washing device 1 is connected to the plurality of molecular sieve adsorption devices 3 through pipes, and the plurality of molecular sieve adsorption devices 3 are connected to the exhaust tower 5 through pipes.

[0099] Several molecular sieve adsorption devices 3 are also equipped with a first circulation pipe 6 and a second circulation pipe 7; the first circulation pipe 6 is equipped with a drying device 2 for rapidly drying the molecular sieve adsorption devices 3; the second circulation pipe 7 is equipped with a cooling device 4 for cooling the molecular sieve adsorption devices 3.

[0100] Several molecular sieve adsorption devices 3 are also connected to high-temperature steam through steam pipes 10 for high-temperature desorption.

[0101] In one specific implementation, the cooling device 4 includes a first cooling component and a second cooling component. The first cooling component is connected to several molecular sieve adsorption devices 3 through pipes. The second cooling component is connected to the first cooling component through a second circulation pipe 7. The drying device 2 is connected to the second cooling component through a first circulation pipe 6.

[0102] The first cooling component includes a first condenser 401, a heat exchanger 402, a brine storage tank 403, and a brine tank pump 404.

[0103] The first condenser 401 is connected to the heat exchanger 402, the brine storage tank 403 and the brine tank pump 404 respectively through the heat exchange pipe 8; the heat exchanger 402 is also connected to the low temperature brine pipe 9, which is used to maintain the temperature of the brine in the heat exchange pipe 8.

[0104] The second cooling component includes a second condenser 405 and a gate valve 406; the second condenser 405 is connected to the first cooling component through a second circulation pipe 7, and the second condenser 405 is also connected to low-temperature cooling water to reduce the gas temperature in the second circulation pipe; the second condenser 405 is also provided with a condensate drain pipe, and a gate valve 406 is provided on the condensate drain pipe.

[0105] Specifically, the low-temperature cooling water in the second condenser 405 is used to cool the moisture in the gas that is released from the second circulation pipe 7.

[0106] Specifically, the first cooling component works in concert with the first condenser 401, heat exchanger 402, brine storage tank 403 and brine tank pump 404 to form a precise temperature control network. Through the combined use of heat exchange pipe 8 and low-temperature brine pipe 9, the temperature of the brine in the heat exchange pipe 8 can be maintained very precisely. This not only removes excess heat from the system but also enables energy reuse, reduces the demand for external cooling resources, and improves overall energy efficiency.

[0107] Specifically, the drying equipment 2 is connected to the second condenser 405 of the cooling equipment 4 through the first circulation pipe 6. When the circulating hot air in the first circulation pipe 6 evaporates the water, the second condenser 405 of the cooling equipment 4 is turned on. The low-temperature brine inside the second condenser 405 cross-exchanges heat with the circulating water vapor, which rapidly reduces the temperature of the water vapor, thereby causing the water vapor to condense into water. The gate valve 406 is then opened to allow the water to be removed through the condensate drain pipe, thus enabling continuous and efficient removal of water.

[0108] When high-pressure steam is introduced into the molecular sieve adsorption device 3, organic gases such as dichloroethane are desorbed from the resin surface and mixed with the high-pressure steam to form high-temperature organic gases. At this time, the second condenser 405 of the cooling device 4 is turned on. The low-temperature brine inside the second condenser 405 cross-exchanges heat with the circulating water vapor, which rapidly reduces the temperature of the water vapor, thereby causing the water vapor to condense into water. The gate valve 406 is then opened to allow the water to be removed through the condensate drain pipe, preparing it for discharge into the environment. This allows for the continuous and efficient removal of water containing mixed organic matter.

[0109] Specifically, the cooling device 4 is equipped with multiple sets of condensers. When organic waste gases such as dichloroethane are present in the desorbed molecular sieve adsorption device 3, the first condenser 401 and the second condenser 405 are turned on to take advantage of the different saturated vapor pressures of organic waste gases and other gases at different temperatures. The organic waste gases are initially cooled to about 40 degrees Celsius by the first condenser 401 and then cooled to 5 degrees Celsius by the second condenser 405. By reducing the temperature to 5 degrees Celsius, some of the organic waste gases such as dichloroethane in the waste gas are converted into liquid and separated. Different sets of condensers can work under progressive temperature gradients. Each stage is used to condense and separate components within a specific temperature range, which can remove organic waste gases more thoroughly.

[0110] However, some organic waste gas remains in the treated gas mixture, which needs to be further treated in the macroporous resin adsorption fixed bed (301).

[0111] Example 3

[0112] like Figure 1-6 As shown in the figure, this embodiment discloses a method for using a VOCs treatment system with desorption function. The method for using the VOCs treatment system includes the following:

[0113] S1: After being collected by the collection system, the organic waste gas first enters the alkaline washing equipment 1 to remove acidic and water-soluble gases from the waste gas. Then the waste gas enters the cooling equipment 4. Relying on the property that the organic waste gas and other gases have different saturated vapor pressures at different temperatures, the temperature is lowered to make some of the organic waste gas turn into liquid and separate it.

[0114] S2: The condensed waste gas enters the molecular sieve adsorption equipment 3 for adsorption. The VOCs in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption equipment 3. The gas that meets the adsorption standards is discharged into the atmosphere through the chimney of the exhaust tower 5.

[0115] S3: When the macroporous resin in the molecular sieve adsorption device 3 reaches saturation, the desorption process is carried out. The inlet and outlet of the adsorption waste gas of the molecular sieve adsorption device 3 are closed, the steam pipe 10 is opened, and high-temperature steam is introduced to desorb the organic gas in the macroporous resin. Subsequently, most of the steam of the mixed organic gas enters the cooling device 4 for cooling and liquefaction. The liquefied wastewater in the cooling device 4 is discharged from the pipe.

[0116] S4: After the molecular sieve adsorption device 3 has completed desorption, stop the steam supply, start the drying device 2 to reduce the humidity in the molecular sieve adsorption device 3 and circulate it in the first circulation pipe 6. Then turn on the cooling device 4 to condense and discharge the water molecules circulating in the molecular sieve adsorption device 3, so that the molecular sieve adsorption device 3 can be dried quickly.

[0117] S5: After the molecular sieve adsorption equipment 3 has finished drying, turn off the drying equipment 2 and use the cooling capacity of the cooling equipment 4 and the internal circulation to cool the system, so as to cool the adsorption material.

[0118] S6: Several molecular sieve adsorption devices 3 are divided into two groups. One group of molecular sieve adsorption devices 3 performs the adsorption process, and the other group performs the desorption process. Several molecular sieve adsorption devices 3 adopt the "one adsorption and one desorption" mode in sequence to ensure that the treated waste gas meets the standards stably.

[0119] Specifically, in this invention, after the organic waste gas is collected by the collection system, it first enters the alkaline washing equipment 1 to remove the hydrogen chloride in the waste gas. Then the waste gas enters the cooling equipment 4. Relying on the property that the organic waste gas and other gases have different saturated vapor pressures at different temperatures, the temperature is reduced by the cooling equipment 4, causing some of the dichloroethane in the waste gas to be converted into liquid and separated.

[0120] After condensation, the waste gas enters several molecular sieve adsorption devices 3 for adsorption and removal of VOCs and other organic gases. The gas that meets the adsorption standards is then discharged into the high atmosphere through the exhaust tower 5.

[0121] When the macroporous resin of one set of molecular sieve adsorption equipment 3 is saturated, the waste gas from the alkaline washing equipment 1 is passed into another set of molecular sieve adsorption equipment 3 for adsorption and collection of organic gases. The saturated molecular sieve adsorption equipment 3 is then connected to the drying equipment 2 and the cooling equipment 4, and water vapor is introduced for desorption and regeneration. The desorbed macroporous resin is then dried and cooled by hot air before entering the adsorption process again. The two sets of molecular sieve adsorption equipment 3 are used in a "one adsorption and one desorption" mode in sequence, so that the adsorption method for treating VOCs and other organic waste gases is constantly switching between adsorption and desorption modes to ensure continuous treatment.

[0122] Specifically, the steam pipe 10 is also equipped with a valve. When it is not necessary to introduce steam into the molecular sieve adsorption device 3, the steam can be prevented from entering by closing the valve on the steam pipe 10.

[0123] The fresh water pipe 12 is also equipped with a valve. When it is necessary to spray water into the biological packing material in the molecular sieve adsorption device 3, the water can be sprayed by closing the valve on the fresh water pipe 12. This can provide the necessary water for the microorganisms in the biological packing material, maintain their life activities, and ensure that their biochemical process of decomposing pollutants proceeds smoothly.

[0124] A valve is also provided on the second circulation pipe 7. When condensation filtration is not required in the second circulation pipe 7, the valve on the second circulation pipe 7 can be closed.

[0125] Working principle

[0126] Because the emissions of waste gas containing organic matter are continuously emitted during the production period, they need to be continuously adsorbed and treated.

[0127] Two sets of molecular sieve adsorption devices 3 containing macroporous resin are connected to the alkaline washing device 1. After the alkaline washing device 1 pre-treats the waste gas, it enters one of the molecular sieve adsorption devices 3. The VOCs and other organic gases in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption device 3. The gas after adsorption treatment meets the standards is discharged at high altitude through the exhaust tower 5.

[0128] When the macroporous resin of a set of molecular sieve adsorption devices 3 is saturated, the waste gas from the condenser 401 is passed into another set of molecular sieve adsorption devices 3 for adsorption and collection of organic gases. The saturated molecular sieve adsorption devices 3 are connected to the drying device 2 and the cooling device 4, and water vapor is introduced for desorption and regeneration. The desorbed macroporous resin is then dried and cooled by hot air before entering the adsorption process again. This cycle is repeated to ensure that the exhaust gas meets the standards.

[0129] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A VOCs treatment system with desorption function, characterized in that, include: Alkali washing equipment (1), drying equipment (2), several molecular sieve adsorption devices (3), cooling equipment (4) and exhaust tower (5); the alkali washing equipment (1) is connected to several molecular sieve adsorption devices (3) through pipes, and the several molecular sieve adsorption devices (3) are connected to the exhaust tower (5) through pipes. Several molecular sieve adsorption devices (3) are also provided with a first circulation pipe (6) and a second circulation pipe (7); the first circulation pipe (6) is provided with a drying device (2) for rapidly drying the molecular sieve adsorption devices (3); the second circulation pipe (7) is provided with a cooling device (4) for cooling the molecular sieve adsorption devices (3); Several molecular sieve adsorption devices (3) are also connected to high-temperature steam through steam pipes (10) for high-temperature desorption; The cooling device (4) includes a first cooling component and a second cooling component. The first cooling component is connected to several molecular sieve adsorption devices (3) through pipes. The second cooling component is connected to the first cooling component through a second circulation pipe (7). The drying device (2) is connected to the second cooling component through a first circulation pipe (6). The first cooling component includes a first condenser (401), a heat exchanger (402), a brine storage tank (403), and a brine tank pump (404). The first condenser (401) is connected to the heat exchanger (402), the brine storage tank (403) and the brine tank pump (404) respectively through the heat exchange pipe (8); the heat exchanger (402) is also connected to the low temperature brine pipe (9) to maintain the temperature of the brine in the heat exchange pipe (8); The drying equipment (2) includes a fan (201) and a heat exchanger (202). The fan (201) is connected to the heat exchanger (202) and provides a power source for the first circulation pipe (6). The heat exchanger (202) is also connected to a steam pipe (10) to heat the air.

2. The VOCs treatment system with desorption function according to claim 1, characterized in that, The alkaline washing equipment (1) includes an alkaline washing tower (101), an alkaline washing tank (102), an alkaline washing heating device (103), a spray water pump (104), and a spray nozzle (105). The bottom of the alkaline washing tower (101) is connected to the alkaline washing tank (102), and the alkaline washing tank (102) is equipped with an alkaline washing heating device (103); the spray water pump (104) is connected to the top of the alkaline washing tower (101) through the spray pipe (106), and sprays chemical agents evenly into the alkaline washing tower (101) through the spray nozzle (105).

3. The VOCs treatment system with desorption function according to claim 2, characterized in that, The alkaline washing tank (102) is also equipped with a floating ball valve (107) for maintaining the water tank level. The alkaline washing tank (102) is connected to the chemical alkaline solution through the alkaline liquid control valve (108). The alkaline washing tank (102) is also equipped with a pH sensor. The alkaline liquid control valve (108) is electrically connected to the pH sensor to maintain the total amount of alkaline solution inside the alkaline washing tank (102).

4. The VOCs treatment system with desorption function according to claim 1, characterized in that, The second cooling component includes a second condenser (405) and a gate valve (406); the second condenser (405) is connected to the first cooling component through a second circulation pipe (7), and the second condenser (405) is also connected to low-temperature cooling water to reduce the gas temperature in the second circulation pipe (7); the second condenser (405) is also provided with a condensate drain pipe, and the condensate drain pipe is provided with a gate valve (406).

5. The VOCs treatment system with desorption function according to claim 1, characterized in that, Several molecular sieve adsorption devices (3) are divided into two groups. Each group of molecular sieve adsorption devices (3) is connected to the alkaline washing device (1) and to the steam pipe (10) through the solenoid valve.

6. The VOCs treatment system with desorption function according to claim 5, characterized in that, A set of molecular sieve adsorption equipment (3) includes two interconnected macroporous resin adsorption fixed beds (301), and a water spray head (11) is connected to the macroporous resin adsorption fixed bed (301) through a solenoid valve.

7. A method of using the VOCs treatment system with desorption function as described in any one of claims 1-6, characterized in that, The method of using the VOCs treatment system includes the following: S1: After being collected by the collection system, the organic waste gas first enters the alkaline washing equipment (1) to remove the acidic and water-soluble gases in the waste gas. Then the waste gas enters the cooling equipment (4). Relying on the property that the organic waste gas and other gases have different saturated vapor pressures at different temperatures, the temperature is lowered to make some of the organic waste gas turn into liquid and separate it. S2: The condensed waste gas enters the molecular sieve adsorption equipment (3) for adsorption. The VOCs components in the waste gas are adsorbed by the macroporous resin material of the molecular sieve adsorption equipment (3). The gas that meets the adsorption treatment standard is discharged into the air through the chimney of the exhaust tower (5). S3: When the macroporous resin in the molecular sieve adsorption device (3) reaches saturation, the desorption process is carried out. The inlet and outlet of the adsorption waste gas of the molecular sieve adsorption device (3) are closed, the steam pipe (10) is opened, and high-temperature water steam is introduced to desorb the organic gas in the macroporous resin. Then most of the mixed organic gas steam enters the cooling device (4) for cooling and liquefaction. The liquefied wastewater in the cooling device (4) is discharged from the pipe. S4: After the molecular sieve adsorption device (3) has finished desorption, stop the steam supply, start the drying device (2) to reduce the humidity in the molecular sieve adsorption device (3) and circulate it in the first circulation pipe (6). Then turn on the cooling device (4) to condense and discharge the water molecules circulating in the molecular sieve adsorption device (3) so that the molecular sieve adsorption device (3) can be dried quickly. S5: After the molecular sieve adsorption equipment (3) has finished drying, turn off the drying equipment (2) and use the cooling capacity of the cooling equipment (4) and the internal circulation to cool the system, so as to cool the adsorption material. S6: Several molecular sieve adsorption devices (3) are divided into two groups. One group of molecular sieve adsorption devices (3) performs the adsorption process, and the other group performs the desorption process. Several molecular sieve adsorption devices (3) adopt the "one adsorption and one desorption" mode in sequence to ensure that the treated waste gas meets the standards stably.

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