Novel VOCs concentration self-adjusting system

Abstract

The utility model relates to a novel VOCs (Volatile Organic Compounds) concentration self-adjusting system which comprises a concentration detection box, a concentration adjusting tower, a desorption tower, an absorption liquid storage tank, a primary circulating pump and a secondary circulating pump, sampling ports of the concentration adjusting tower, the desorption tower and the absorption liquid storage tank are connected with a sampling inlet of the concentration detection box, and the concentration detection box is used for detecting the concentration of the absorption liquid discharged by the concentration adjusting tower and the desorption tower; the reflux inlets of the concentration adjusting tower, the desorption tower and the concentration detection box are connected with the absorption liquid inlet of the absorption liquid storage tank; two absorption liquid outlets of the absorption liquid storage tank are respectively connected with absorption liquid inlets of the concentration adjusting tower and the desorption tower through a primary circulating pump and a secondary circulating pump; gas outlets of the concentration adjusting tower and the desorption tower are both connected with a waste gas treatment system, and air discharged by the desorption tower is used for adjusting the concentration of VOCs in waste gas at the gas outlet of the concentration adjusting tower.

Description

Technical Field

[0001] The utility model relates to a novel VOCs concentration self-regulating system, belonging to the technical field of waste gas purification. Background Art

[0002] In the production process of petrochemical, coal chemical, pharmaceutical, fine chemical, packaging and printing and other industrial fields, a large amount of VOCs are inevitably generated and emitted due to process needs, which seriously affects the ecological environment and human health. At the same time, many production processes are intermittent operations, and the organic waste gas generated also has the characteristics of intermittent fluctuations, especially the exhaust gas from storage tanks of petrochemical enterprises and the tail gas from synthesis tanks of pharmaceutical enterprises. These waste gases often have the characteristics of high emission intensity and long fluctuation time. Intermittent organic waste gas is widely present in the process production of petrochemical, pharmaceutical, fine chemical and other industries. According to statistics from many scholars, the proportion of storage tank emissions in the VOCs emissions of petrochemical enterprises is 28% to 49%, and the VOCs tail gas emissions from the synthesis process account for more than 70% of the total emissions of pharmaceutical companies.

[0003] In order to effectively control VOCs emissions, end-of-pipe treatment processes such as adsorption, condensation, absorption, combustion, and biological treatment are currently commonly used to eliminate organic components in waste gas. However, most VOCs treatment processes require a stable VOCs emission environment to achieve better treatment effects. When faced with the above-mentioned non-steady-state emission conditions, the operating load range of organic waste gas treatment facilities will be too large, which will lead to higher equipment investment costs and operating energy consumption. At the same time, intermittent fluctuations in VOCs will not only affect treatment efficiency, but more importantly, may bring great safety hazards. Therefore, it is crucial to effectively regulate the concentration of VOCs emitted in chemical industrial reactions.

[0004] The current mainstream concentration adjustment methods mainly include buffer tanks and adsorption buffer processes:

[0005] The buffer tank uses a large volume to temporarily store a certain amount of organic waste gas. VOCs of different concentrations will be mixed evenly in the tank and then discharged. The buffer tank has a good buffering effect on waste gas with short duration and small fluctuation, but it cannot effectively deal with waste gas conditions with long duration and large concentration changes. At the same time, the buffer tank process has obvious defects such as large equipment size and high safety risks.

[0006] The adsorption buffering process uses the concentration balance of VOCs on the surface of the adsorption material to adjust the concentration fluctuation of organic waste gas. It is suitable for low-frequency, small-scale intermittent waste gas buffering. The main disadvantages of the existing adsorption buffering process are: (1) The saturated adsorption capacity of the existing adsorption material is low, and the equilibrium concentration needs to be controlled at a low level, which cannot effectively buffer the waste gas with large concentration fluctuations; (2) The desorption process is relatively cumbersome and requires additional consumption of nitrogen or heat for effective desorption; (3) The adsorption material is saturated for a long time, the life span decreases rapidly, and frequent replacement leads to high operating costs. Utility Model Content

[0007] In order to solve the problems existing in the above-mentioned prior art, the utility model provides a novel VOCs concentration self-regulating system, in which the principle of like dissolves like is used to buffer intermittently fluctuating organic waste gas through absorption liquid in the concentration regulating system; the difference in capillary effect of absorption liquids with different concentrations is used as a novel concentration detection method, and the VOCs concentrations of multiple absorption liquids in the concentration regulating system are monitored in real time to indirectly feedback the gas phase concentration level in the system; a new control logic is used to control the multi-stage concentration balance device to exert a buffering effect, so as to achieve a stable VOCs concentration at the outlet of the concentration regulating system and meet the concentration requirements for stable operation of subsequent treatment equipment.

[0008] The technical solution of the utility model is as follows:

[0009] A new type of VOCs concentration self-regulating system, including a concentration detection box, a concentration regulating tower, a desorption tower, an absorption liquid storage tank, a primary circulation pump, and a secondary circulation pump;

[0010] The sampling ports of the concentration adjusting tower, desorption tower and absorption liquid storage tank are all connected to the sampling inlet of the concentration detection box, and the concentration detection box is used to detect the concentration of the absorption liquid discharged from the concentration adjusting tower and the desorption tower; the reflux ports of the concentration adjusting tower, the desorption tower and the concentration detection box are all connected to the absorption liquid inlet of the absorption liquid storage tank; the two absorption liquid outlets of the absorption liquid storage tank are respectively connected to the absorption liquid inlets of the concentration adjusting tower and the desorption tower through a primary circulation pump and a secondary circulation pump; the air outlets of the concentration adjusting tower and the desorption tower are both connected to the exhaust gas treatment system, and the air discharged from the desorption tower is used to adjust the concentration of VOCs in the exhaust gas at the air outlet of the concentration adjusting tower.

[0011] Preferably, an exhaust gas blower is also installed, wherein the inlet of the exhaust gas blower inputs the organic waste gas, and the outlet of the exhaust gas blower is connected to the air inlet at the bottom of the concentration regulating tower.

[0012] Preferably, a buffer fan and a micro heater are also installed, the inlet of the micro heater inputs air, and the outlet is connected to the air inlet at the bottom of the desorption tower through the buffer fan.

[0013] Preferably, the concentration detection box is provided with a concentration detection component, a sampling pump, a detection wheel, a liquid collecting box and a drying fan; a plurality of groups of concentration detection components are provided on the outer periphery of the detection wheel; sampling pumps are provided on the sampling pipes at the bottom of the concentration adjustment tower and the desorption tower and the sampling pipes of the absorption liquid storage tank, and the ends of the sampling pipes extend into the concentration detection box and are located above the concentration detection components; the liquid collecting box is provided below the detection wheel, and the drying fan is provided on the side of the detection wheel.

[0014] Preferably, the concentration detection component comprises a regulating tower bottom liquid tank, a storage tank liquid tank, a desorption tower bottom liquid tank, a detection capillary and a height sensor; the regulating tower bottom liquid tank, the storage tank liquid tank and the desorption tower bottom liquid tank are arranged side by side; detection capillaries of the same size are arranged in the center of the regulating tower bottom liquid tank, the storage tank liquid tank and the desorption tower bottom liquid tank; each detection capillary is perpendicular to the plane of the box body and arranged in the central position of the box body, and is inserted into the interior of the box body at the same time, and the height of each detection capillary remains consistent; a plurality of vertically distributed height sensors are arranged on the inner wall of the concentration detection box at a position directly opposite to the detection capillary, and the height sensor is used to detect the liquid level in each detection capillary; the bottom sampling pipes of the concentration regulating tower and the desorption tower and the ends of the sampling pipes of the absorption liquid storage tank are correspondingly arranged directly above the regulating tower bottom liquid tank, the storage tank liquid tank and the desorption tower bottom liquid tank.

[0015] Preferably, the sampling ports of the concentration adjustment tower and the desorption tower are both opened at the bottom of the tower, and are connected to the sampling port of the concentration detection box through a sampling pipe; the sampling port of the absorption liquid storage tank is opened at the top of the tank, and is connected to the sampling port of the concentration detection box through a sampling pipe.

[0016] Preferably, the reflux ports of the concentration adjustment tower, desorption tower and concentration detection box are all opened at the bottom of the tower and the bottom of the box, and are connected to the absorption liquid inlet of the absorption liquid storage tank through a reflux pipe.

[0017] Preferably, the absorption liquid inlets of the concentration adjusting tower and the desorption tower are both opened at the top of the tower.

[0018] Preferably, the gas outlets of the concentration adjustment tower and the desorption tower are both opened at the top of the tower.

[0019] Preferably, a plurality of metal wire mesh fillers with a high specific surface area are installed inside the concentration adjustment tower and the desorption tower.

[0020] The utility model has the following beneficial effects:

[0021] 1. The utility model uses a concentration adjustment tower and a desorption tower to achieve multi-level adjustment of the VOCs concentration in the organic waste gas, ensuring that the VOCs concentration in the final output organic waste gas meets the requirements of subsequent treatment equipment;

[0022] 2. The concentration regulating tower and desorption tower in the utility model are both packed towers, and the material is selected as a metal mesh packing with a high specific surface area; the selection of metal can avoid static electricity accumulation, and the metal mesh packing is selected as the place where the organic waste gas and the absorption liquid are transferred between the two phases.

[0023] 3. The utility model adopts a concentration detection box with a new structure. By setting up a number of concentration detection components, the detection can be carried out continuously. The residual droplets on the surface of the capillary are blown away by a dry fan to ensure the accuracy of the next round of concentration detection. Through continuous and accurate detection, the VOCs concentration of organic waste gas in each packing tower can be monitored in real time.

[0024] 4. The utility model introduces the absorption liquid in each tower and storage tank into the capillary, uses the principle of difference in capillary effect of solutions with different concentrations to monitor the concentration of liquid VOCs from different sources, and indirectly quantifies and feeds back the corresponding gas-phase VOCs concentration, thereby achieving adaptive and precise concentration control. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the novel VOCs concentration self-regulating system of the utility model;

[0026] Figure 2 It is a schematic diagram of the structure of the concentration detection box;

[0027] Figure 3 It is a schematic diagram of the structure of the concentration detection component;

[0028] Figure 4 It is the operation logic diagram of the automatic control system;

[0029] The reference numerals in the figure are as follows:

[0030] 1. Concentration detection box; 2. Concentration adjustment tower; 3. Desorption tower; 4. Absorption liquid storage tank; 5. Primary circulation pump; 6. Secondary circulation pump; 7. Exhaust fan; 8. Buffer fan; 9. Micro heater; 11. Concentration detection group; 12. Sampling pump; 13. Detection wheel; 14. Liquid collecting box; 15. Drying fan; 111. Adjustment tower bottom liquid tank; 112. Storage tank liquid tank; 113. Desorption tower bottom liquid tank; 114. Detection capillary; 115. Height sensor. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the novel VOCs concentration self-regulating system of this embodiment includes a concentration detection box 1, a concentration regulating tower 2, a desorption tower 3, an absorption liquid storage tank 4, a primary circulation pump 5, and a secondary circulation pump 6;

[0033] The sampling ports of the concentration adjusting tower 2, the desorption tower 3 and the absorption liquid storage tank 4 are all connected to the sampling inlet of the concentration detection box 1, and the concentration detection box 1 is used to detect the concentration of the absorption liquid discharged from the concentration adjusting tower 2 and the desorption tower 3; the reflux ports of the concentration adjusting tower 2, the desorption tower 3 and the concentration detection box 1 are all connected to the absorption liquid inlet of the absorption liquid storage tank 4; the two absorption liquid outlets of the absorption liquid storage tank 4 are respectively connected to the absorption liquid inlets of the concentration adjusting tower 2 and the desorption tower 3 through the primary circulation pump 5 and the secondary circulation pump 6; the air outlets of the concentration adjusting tower 2 and the desorption tower 3 are both connected to the exhaust gas treatment system, and the air discharged from the desorption tower 3 is used to adjust the concentration of VOCs in the exhaust gas at the air outlet of the concentration adjusting tower 2.

[0034] In this embodiment, the working principle of the utility model is as follows:

[0035] According to the process flow of organic waste gas, waste gas is generated by waste gas sources such as storage tanks and process equipment, collected and sent to the air duct, and then pressurized by the waste gas fan 7 and enters the tower through the bottom entrance of the concentration adjustment tower 2. A large number of metal wire mesh fillers with high specific surface area are installed in the tower as a place for mass transfer between organic waste gas and absorption liquid (when the concentration of VOCs in organic waste gas and the concentration of VOCs in absorption liquid have not reached a state of equilibrium, VOCs molecules will be transferred between gas and liquid, also known as gas-liquid mass transfer, until the VOCs concentration between the two phases reaches a state of equilibrium). After the initial absorption / desorption adjustment in the concentration adjustment tower 2, the waste gas with small fluctuations will meet the design concentration requirements, and then be sent to the treatment equipment to complete the purification process and discharge. After the VOCs with large concentration fluctuations are adjusted by the adjustment tower, their concentration is close to the design fluctuation range, and then mixed with the balance wind introduced from the top of the desorption tower 3, and the secondary concentration balance adjustment is performed, and the concentration of organic matter in the waste gas can meet the requirements of the treatment equipment.

[0036] According to the process flow of the absorption liquid, the primary circulation pump 5 pressurizes part of the absorption liquid in the absorption liquid storage tank 4 and sends it to the top of the concentration adjustment tower 2. The absorption liquid is converted into a number of small droplets through the high-pressure atomizing nozzle, and gradually falls under the influence of gravity. The intermittently fluctuating organic waste gas and the absorption liquid droplets mostly scattered on the surface of the packing in the tower and a small part of the floating in the air undergo gas-liquid mass transfer. Finally, most of the absorption liquid is collected at the bottom of the tower, and is combined with the absorption liquid at the bottom of the desorption tower 3 through the reflux pipe and refluxed into the storage tank. Sampling tubes are set at the bottom of the concentration adjustment tower 2 and the desorption tower 3 to extract trace absorption liquid into the concentration detection box 1 for detecting the concentration of organic components of waste gas in the absorption liquid.

[0037] A fresh air inlet is arranged at the bottom of the desorption tower 3, which is connected to the buffer fan 8 and the micro heater 9. The tower is also provided with fillers with a high specific surface area. The organic matter concentration of the balance wind at the top outlet of the tower is controlled to be high or low by adjusting the absorption liquid flow rate of the desorption tower 3 and the operating frequency of the buffer fan 8, respectively, so as to realize the functions of enriching and diluting the exhaust gas at the outlet of the concentration regulating tower 2 with supplementary air.

[0038] Because a large number of high specific surface area fillers are provided in the concentration adjustment tower 2 and the desorption tower 3, the internal gas-liquid mass transfer can reach a relatively balanced state, so the concentration detection method adopted by this system is to use the concentration detection box 1 to respectively detect and compare the concentration levels of the absorption liquid at the bottom outlet of the concentration adjustment tower 2, the bottom outlet of the desorption tower 3 and the absorption liquid storage tank 4, and indirectly feedback the VOCs concentration in the exhaust gas at the top outlet of the concentration adjustment tower 2 and the top outlet of the desorption tower 3. Because a large amount of absorption liquid is stored in the absorption liquid storage tank 4, and the amount of absorption liquid in the concentration adjustment tower 2 and the desorption tower 3 is small, the reflux to the storage tank will not have a significant effect on the concentration of the liquid in the tank in a short time, so the absorption liquid at the bottom of the absorption liquid storage tank 4 is selected as the detection comparison benchmark to improve the stability of concentration detection and the accuracy of the results.

[0039] Furthermore, an exhaust gas fan 7 is installed, the inlet of the exhaust gas fan 7 inputs the organic waste gas, and the outlet of the exhaust gas fan 7 is connected to the air inlet at the bottom of the concentration adjustment tower 2.

[0040] Furthermore, a buffer fan 8 and a micro heater 9 are installed. Air is input through the inlet of the micro heater 9, and the outlet is connected to the air inlet at the bottom of the desorption tower 3 through the buffer fan 8.

[0041] In this embodiment, the installation diagram of the exhaust fan 7, the buffer fan 8 and the micro heater 9 is as follows: Figure 1 shown.

[0042] Furthermore, a concentration detection component 11, a sampling pump 12, a detection wheel 13, a liquid collecting box 14 and a drying fan 15 are arranged in the concentration detection box 1; a plurality of groups of concentration detection components 11 are arranged on the outer periphery of the detection wheel 13; a sampling pump 12 is arranged on the bottom sampling pipes of the concentration adjustment tower 2 and the desorption tower 3 and the sampling pipes of the absorption liquid storage tank 4, and the ends of the respective sampling pipes extend into the concentration detection box 1 and are located above the respective concentration detection components 11; the liquid collecting box 14 is arranged below the detection wheel 13, and the drying fan 15 is arranged on the side of the detection wheel 13.

[0043] In this embodiment, the internal structure of the concentration detection box 1 is as follows: Figure 2 As shown, the working principle of the concentration detection box 1 is as follows:

[0044] The detection wheel 13 adopts an intermittent rotation operation strategy. When detection is required, the detection wheel 13 will rotate to an angle so that a certain group of concentration detection components 11 are directly below the sampling pipeline, and the sampling pump 12 extracts the absorption liquid to be tested and injects it into the detection box of the concentration detection component 11 for detection. After the detection is completed, the detection wheel 13 starts to rotate, and the concentration detection component 11 is driven to face downward. The liquid flows downward into the liquid collection box 14 and finally flows back to the absorption liquid storage tank 4 through the pipeline. In order to prevent a small amount of absorption liquid from remaining in the concentration detection component 11, a drying fan 15 is arranged on the side of the detection wheel 13. When the wheel rotates, the circulating wind can be used to take away the residual droplets on the surface of the detection capillary 114 to ensure the accuracy of the next round of concentration detection.

[0045] The mechanism of absorption liquid concentration detection is that solutions of different concentrations have different surface tensions of the entire solution due to the different intermolecular forces of the internal solutes. When a capillary is inserted into the solution, the liquid level in the capillary will rise to different heights due to the different surface tensions, and detection can then be performed on different liquid level heights.

[0046] Furthermore, the concentration detection component 11 includes a regulating tower bottom liquid tank 111, a storage tank liquid tank 112, a desorption tower bottom liquid tank 113, a detection capillary 114 and a height sensor 115; the regulating tower bottom liquid tank 111, the storage tank liquid tank 112 and the desorption tower bottom liquid tank 113 are arranged side by side; the regulating tower bottom liquid tank 111, the storage tank liquid tank 112 and the desorption tower bottom liquid tank 113 are all provided with detection capillaries 114 of the same size in the center of the box body; each detection capillary 114 is perpendicular to the box body plane and arranged at the center of the box body. and inserted into the box body at the same time, so that the height of each detection capillary 114 remains consistent; a plurality of vertically distributed height sensors 115 are arranged on the inner wall of the concentration detection box 1 at a position directly opposite to the detection capillary 114, and the height sensor 115 is used to detect the liquid level in each detection capillary 114; the sampling pipes at the bottom of the concentration regulating tower 2 and the desorption tower 3 and the ends of the sampling pipes of the absorption liquid storage tank 4 are correspondingly arranged directly above the regulating tower bottom liquid tank 111, the storage tank liquid tank 112 and the desorption tower bottom liquid tank 113.

[0047] In this embodiment, the internal structure of the concentration detection component 11 is as follows: Figure 3 As shown, the working process of the concentration detection component 11 is as follows:

[0048] At the beginning of the test, the test box 1 will extract a small amount of liquid from the concentration adjustment tower 2, the desorption tower 2 and the absorption liquid storage tank 4 to fill the adjustment tower bottom liquid tank 111, the storage tank liquid tank 112 and the desorption tower bottom liquid tank 113 respectively. The absorption liquids in the three tanks will produce a capillary effect due to the different VOCs concentrations contained in each of them, that is, there will be a difference in the liquid level height in the three capillaries. The liquid level height difference is then detected by a number of height sensors 115 and converted into an electrical signal, which is sent to the control system as a condition for subsequent control parameter changes.

[0049] Furthermore, the sampling ports of the concentration adjustment tower 2 and the desorption tower 3 are both opened at the bottom of the towers, and are connected to the sampling port of the concentration detection box 1 through a sampling pipe; the sampling port of the absorption liquid storage tank 4 is opened at the top of the tank, and is connected to the sampling port of the concentration detection box 1 through a sampling pipe.

[0050] Furthermore, the reflux ports of the concentration adjustment tower 2 , the desorption tower 3 and the concentration detection box 1 are all opened at the bottom of the tower and the box, and are connected to the absorption liquid inlet of the absorption liquid storage tank 4 through a reflux pipeline.

[0051] Furthermore, the absorption liquid inlets of the concentration adjustment tower 2 and the desorption tower 3 are both opened at the top of the tower.

[0052] Furthermore, the gas outlets of the concentration adjustment tower 2 and the desorption tower 3 are both opened at the top of the tower.

[0053] Furthermore, a plurality of metal wire mesh fillers with a high specific surface area are installed inside the concentration adjustment tower 2 and the desorption tower 3 .

[0054] In this embodiment, the metal wire mesh filler with a high specific surface area serves as a place for mass transfer between the organic waste gas and the absorption liquid.

[0055] Embodiment 2:

[0056] Based on the system structure in the first embodiment, the automatic control system is combined to realize the automatic adjustment of the VOCs concentration in the organic waste gas. The operation logic of the automatic control system is as follows: Figure 4 As shown, the specific process is as follows:

[0057] When the exhaust gas concentration level is at a high level, firstly, through the regulating effect of the concentration regulating tower 2, most of the gas phase organic matter can be absorbed and transferred to the liquid phase. After the concentration detection, if the concentration of the bottom solution of the concentration regulating tower 2 is too high (the capillary height difference between the bottom liquid tank 111 of the regulating tower and the bottom liquid tank 113 of the desorption tower is large), the absorption liquid flow rate of the concentration regulating tower 2 is increased, and at the same time, the secondary circulation pump 6 and the buffer fan 8 are turned on to input fresh air to the desorption tower 3, the absorption liquid desorption process is started, and the absorption liquid concentration at the bottom of the desorption tower 3 is monitored synchronously. The dual measures of "absorption + a small amount of dilution" are used to ensure that the high-concentration exhaust gas at the front end can be adjusted to the designed range; when the height difference gradually decreases, the desorption tower 3, the secondary circulation pump 6 and the buffer fan 8 are gradually closed, and the parameters such as the liquid flow rate of the concentration regulating tower 2 are gradually adjusted back to the normal state.

[0058] When the front-end exhaust gas source produces less VOCs, the gas phase concentration at the system inlet is low, and some of the VOCs previously stored in the absorption liquid will be released in the concentration adjustment tower 2 and transferred from the liquid phase to the gas phase through gas-liquid mass transfer, thereby achieving low concentration compensation for the exhaust gas. When the concentration detection result shows that the concentration of the bottom solution of the concentration regulating tower 2 is low (the capillary height difference between the bottom liquid tank 111 of the regulating tower and the bottom liquid tank 113 of the desorption tower is small), the liquid flow rate of the concentration regulating tower 2 is slightly increased, and the concentration monitoring is maintained, which can help keep the concentration of the organic waste gas stable; if the detection result shows that the concentration of the bottom solution of the concentration regulating tower 2 is too low (the capillary height difference between the bottom liquid tank 111 of the regulating tower and the bottom liquid tank 113 of the desorption tower is large), the absorption liquid flow rate of the concentration regulating tower 2 is appropriately increased, and the desorption tower 3, the secondary circulation pump 6, the buffer fan 8 and the micro heater 9 are turned on, and the absorption liquid is desorbed by fresh air with a higher temperature, and an organic waste gas with a certain concentration is formed at the bottom outlet of the desorption tower 3, and the main organic matter concentration is supplemented for a second time, so as to achieve the regulation of low-concentration organic waste gas and maintain its concentration within the design requirements.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 present invention.

Claims

1. A new type of VOCs concentration self-regulating system, characterized in that: It comprises a concentration detection box (1), a concentration adjustment tower (2), a desorption tower (3), an absorption liquid storage tank (4), a primary circulation pump (5), and a secondary circulation pump (6); The sampling ports of the concentration regulating tower (2), the desorption tower (3) and the absorption liquid storage tank (4) are all connected to the sampling inlet of the concentration detection box (1), and the concentration detection box (1) is used to detect the concentration of the absorption liquid discharged from the concentration regulating tower (2) and the desorption tower (3); the reflux ports of the concentration regulating tower (2), the desorption tower (3) and the concentration detection box (1) are all connected to the absorption liquid inlet of the absorption liquid storage tank (4); the two absorption liquid outlets of the absorption liquid storage tank (4) are respectively connected to the absorption liquid inlets of the concentration regulating tower (2) and the desorption tower (3) through a primary circulation pump (5) and a secondary circulation pump (6); the air outlets of the concentration regulating tower (2) and the desorption tower (3) are all connected to the waste gas treatment system, and the air discharged from the desorption tower (3) is used to regulate the concentration of VOCs in the waste gas at the air outlet of the concentration regulating tower (2).

2. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: An exhaust gas fan (7) is also installed, the inlet of the exhaust gas fan (7) inputs organic exhaust gas, and the outlet is connected to the air inlet at the bottom of the concentration adjustment tower (2).

3. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: A buffer fan (8) and a micro heater (9) are also installed. Air is input into the inlet of the micro heater (9), and the outlet is connected to the air inlet at the bottom of the desorption tower (3) through the buffer fan (8).

4. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: The concentration detection box (1) is provided with a concentration detection component (11), a sampling pump (12), a detection wheel (13), a liquid collecting box (14) and a drying fan (15); a plurality of groups of concentration detection components (11) are provided on the outer periphery of the detection wheel (13); the sampling pipes at the bottom of the concentration adjustment tower (2) and the desorption tower (3) and the sampling pipes of the absorption liquid storage tank (4) are provided with sampling pumps (12), and the ends of the sampling pipes extend into the concentration detection box (1) and are located above the concentration detection components (11); the liquid collecting box (14) is provided below the detection wheel (13), and the drying fan (15) is provided on the side of the detection wheel (13).

5. A novel VOCs concentration self-regulating system according to claim 4, characterized in that: The concentration detection assembly (11) comprises a regulating tower bottom liquid tank (111), a storage tank liquid tank (112), a desorption tower bottom liquid tank (113), a detection capillary (114) and a height sensor (115); the regulating tower bottom liquid tank (111), the storage tank liquid tank (112) and the desorption tower bottom liquid tank (113) are arranged side by side; detection capillaries (114) of the same size are arranged in the center of the regulating tower bottom liquid tank (111), the storage tank liquid tank (112) and the desorption tower bottom liquid tank (113); each detection capillary (114) is perpendicular to the plane of the box and arranged in the center of the box The detection capillaries (114) are arranged at the same position and inserted into the box body at the same time, and the height of each detection capillary (114) is kept consistent; a plurality of vertically distributed height sensors (115) are arranged on the inner wall of the concentration detection box (1) at a position directly opposite to the detection capillary (114), and the height sensors (115) are used to detect the liquid level in each detection capillary (114); the bottom sampling pipes of the concentration regulating tower (2) and the desorption tower (3) and the ends of the sampling pipes of the absorption liquid storage tank (4) are correspondingly arranged directly above the regulating tower bottom liquid tank (111), the storage tank liquid tank (112) and the desorption tower bottom liquid tank (113).

6. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: The sampling ports of the concentration adjustment tower (2) and the desorption tower (3) are both opened at the bottom of the towers and connected to the sampling port of the concentration detection box (1) through a sampling pipeline; the sampling port of the absorption liquid storage tank (4) is opened at the top of the tank and connected to the sampling port of the concentration detection box (1) through a sampling pipeline.

7. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: The reflux ports of the concentration adjustment tower (2), the desorption tower (3) and the concentration detection box (1) are all located at the bottom of the tower and the bottom of the box, and are connected to the absorption liquid inlet of the absorption liquid storage tank (4) through a reflux pipeline.

8. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: The absorption liquid inlets of the concentration adjustment tower (2) and the desorption tower (3) are both opened at the top of the tower.

9. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: The gas outlets of the concentration adjustment tower (2) and the desorption tower (3) are both opened at the top of the tower.

10. A novel VOCs concentration self-regulating system according to claim 1, characterized in that: A plurality of metal wire mesh fillers with a high specific surface area are installed inside the concentration adjustment tower (2) and the desorption tower (3).

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