An integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system

Abstract

The present invention discloses an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, which relates to the field of waste gas treatment technology, including a waste gas input boosting unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit and a solvent storage unit. The tail gas treatment optimization unit includes a cold recovery heat exchanger and a demister; the top and bottom ends of the demister are the exhaust end and the air intake end, respectively, and the interior of the demister is provided with a bent plate demister mechanism and an active cleaning mechanism. The entire system of the present invention organically combines the waste gas input boosting unit, the liquid nitrogen condensation recovery unit, the tail gas treatment optimization unit and the solvent storage unit, realizing an integrated process from waste gas input to solvent recovery and tail gas treatment, with a reasonable design and compact structure, improving the overall operating efficiency and stability of the system, and having high social use value and application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of waste gas treatment, and in particular to an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system. Background Art

[0002] In the industrial sector, the control of volatile organic compounds (VOCs) has always been a key and challenging issue in environmental protection efforts. For companies using organic solvents as raw materials, the organic waste gases emitted during production pose numerous challenges to both the environment and business development.

[0003] If waste gas containing organic substances such as ether and ethyl chloride is directly discharged without proper treatment, on the one hand, it will cause serious pollution to the atmospheric environment, affect air quality, cause environmental problems such as smog, and pose a threat to the ecosystem and human health; on the other hand, from the perspective of corporate economic benefits, organic substances such as ether and ethyl chloride in waste gas have certain recycling value, and direct discharge causes waste of resources.

[0004] Traditional organic waste gas treatment processes have numerous drawbacks when dealing with this type of waste gas. For example, while adsorption can absorb some organic matter, the adsorbent easily becomes saturated and requires frequent regeneration, which not only increases operating costs but can also lead to substandard waste gas treatment due to incomplete adsorption. While combustion can decompose organic matter, it consumes significant energy and can produce secondary pollutants such as nitrogen oxides during high-temperature combustion, further increasing the environmental burden. Furthermore, some traditional processes have low recovery efficiency for organic matter in waste gas, making it difficult to effectively recycle resources.

[0005] Traditional demisters in waste gas treatment systems are difficult to clean and maintain when dealing with complex organic waste gas compositions. The complex composition of organic waste gas easily leads to stubborn oil and dirt buildup inside the demister. The structural design of traditional demisters makes it difficult to reach every corner, resulting in incomplete cleaning. Frequent manual cleaning not only consumes significant manpower, material resources, and time, but can also damage the demister due to improper operation, increasing repair costs and downtime, impacting normal production. Summary of the Invention

[0006] In order to solve the problems mentioned in the above background technology, the present invention provides an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] An integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, comprising a waste gas input pressurization unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit and a solvent storage unit, wherein the tail gas treatment optimization unit comprises a cold recovery heat exchanger and a demister;

[0009] The top and bottom ends of the demister are respectively the exhaust end and the air intake end. The interior of the demister is provided with a bent plate demister mechanism and an active cleaning mechanism. The bent plate demister mechanism is provided with multiple groups of parallel bent guide plates. The bent guide plates are composed of multiple sub-guide plates. Each sub-guide plate is hinged end to end, and the bent guide plates can be converted into a straight state by rotation.

[0010] Preferably, the exhaust gas input boosting unit is a Roots blower, and the liquid nitrogen condensation recovery unit is composed of a liquid nitrogen condenser and a liquid nitrogen mixer, and the liquid nitrogen condenser adopts a cryogenic shell and tube structure.

[0011] Preferably, the top and bottom ends of the demister are respectively provided with an exhaust air collecting hood and an air intake machine hood, the top end of the exhaust air collecting hood is installed with an exhaust pipe, the bottom end of the air intake machine hood is installed with an air intake pipe, and the bottom end of the air intake pipe is provided with a sewage discharge branch.

[0012] Preferably, fixed brackets are fixed on the inner walls on both sides of the demister, connecting shafts are fixed on the four corners of the sub-deflector, and the first straight gear is fixed on the connecting shafts, wherein the connecting shafts close to each other on the two sub-deflector plates are rotatably mounted on the fixed brackets, and multiple sub-deflector plates are hinged in sequence on the sides of the two sub-deflector plates that are away from each other.

[0013] Preferably, a series bracket is fixed on the branch guide plate at a position away from the fixed bracket, and the next branch guide plate is rotated and connected through the series bracket, and the first spur gears on adjacent branch guide plates are engaged with each other to ensure stability when rotating with each other, and a first arc-shaped rack is fixed on the fixed bracket, and a second arc-shaped rack is fixed on the series bracket.

[0014] Preferably, a transmission rod is rotatably installed on the sub-deflector through a supporting horizontal bar, and a transmission shaft is rotatably installed on the side of the supporting horizontal bar close to the previous sub-deflector. A second bevel gear is fixed on the connecting shaft that is rotatably connected to the series bracket on the current sub-deflector, and a second spur gear and a first bevel gear are fixed on the transmission shaft. The second spur gear is meshed with the first arc rack or the second arc rack on the previous sub-deflector, and third bevel gears are fixed at both ends of the transmission rod. The third bevel gear at one end of the transmission rod is meshed with the first bevel gear on the current sub-deflector, and the third bevel gear at the other end of the transmission rod is meshed with the second bevel gear on the next sub-deflector.

[0015] Preferably, a worm gear is rotatably mounted on the fixed bracket, the worm gear is fixed to the connecting shaft on one of the branch guide plates, and a power input shaft rotates inside the demister, a worm is fixed on the power input shaft, the worm is engaged with the worm gear, and the worm is driven to rotate by the first rotating motor.

[0016] Preferably, the active cleaning mechanism includes a plurality of horizontal ducts, both ends of which are slidably mounted on vertical slide rails on the inner wall of the demister through sliders, the horizontal ducts are located above the gap between two adjacent sets of bent guide plates, and scrapers are rotatably mounted on both sides of the bottom end of the horizontal ducts through brackets, a return spring is fixed between the top end of the scraper and the bracket, and a limiting baffle is fixed on the bracket on one side of the top end of the scraper.

[0017] Preferably, a plurality of cleaning liquid nozzles are fixed to the bottom end of the horizontal conduit, a vertical conduit is fixed to the top end of the horizontal conduit, a cleaning liquid inlet pipe is installed on the outer wall of the demister, and the cleaning liquid inlet pipe is connected to each vertical conduit through a hose to ensure that the horizontal conduit remains connected during the lifting and lowering movement. A limit frame is fixed on the inner wall of the demister, and the limit frame is provided with two limit branches, and the two branches are located on both sides above the horizontal conduit.

[0018] Preferably, a bar magnet is mounted on the outer wall of the demister so that it can be lifted and lowered, a magnetic block is provided on the slider, and the bar magnet and the magnetic block attract each other, so that when the bar magnet moves up and down, it can drive the horizontal duct to move up and down, and a second rotating motor is fixed on the outer wall of the demister, and a threaded rod is fixed on the output shaft of the second rotating motor, and the threaded rod passes through the bar magnet through a threaded hole.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Efficient Demisting and Cleaning: The demister features a curved demisting mechanism. Its curved deflector, comprised of multiple hinged deflectors, can be switched between a curved and straight position. In the curved position, it effectively blocks mist droplets from the exhaust, delivering effective demisting. When cleaning is required, it switches to a straight position for easier cleaning and avoids blind spots. An active cleaning mechanism automatically cleans the curved deflector. A cleaning fluid nozzle on the horizontal duct sprays water for cleaning, while a scraper removes oil and dirt, enhancing cleaning efficiency and effectiveness. Furthermore, a stopper protects the cleaning fluid nozzle when not in the cleaning position, extending its service life.

[0021] 2. Good structural stability and transmission coordination: By arranging a connecting shaft and a first spur gear at the corner of the sub-deflector, as well as a first arc-shaped rack on the fixed bracket and a second arc-shaped rack on the series bracket, in conjunction with transmission components such as a transmission rod, a bevel gear and a spur gear, multiple sub-deflectors can rotate synchronously relative to each other under a single rotational power input, thereby achieving rapid and stable conversion of the bent deflector between the straight and bent states.

[0022] 3. Advantages of Cold Recovery and System Integration: The cold recovery heat exchanger in the exhaust gas treatment optimization unit recovers cold from the exhaust gas, improving cold utilization. The entire system organically combines the exhaust gas input boosting unit, liquid nitrogen condensation recovery unit, exhaust gas treatment optimization unit, and solvent storage unit, achieving an integrated process from exhaust gas input to solvent recovery and exhaust gas treatment. Its rational design and compact structure improve the overall operating efficiency and stability of the system, and it has high social value and application prospects.

[0023] 4. Automated cleaning and convenient operation: The horizontal guide tube of the active cleaning mechanism is magnetically connected to the bar magnet through a slider, and the second rotary motor drives the threaded rod to achieve lifting and movement. It has a high degree of automation and convenient operation, reducing the workload and difficulty of manual cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 is a flow chart of the present invention;

[0026] Figure 2 A perspective view of a demister according to the present invention;

[0027] Figure 3 This is a front view of the demister of the present invention;

[0028] Figure 4 It is a left side view of the present invention;

[0029] Figure 5 is a three-dimensional cross-sectional view of the present invention;

[0030] Figure 6 Schematic diagram of the matching relationship between the worm wheel and the worm of the present invention;

[0031] Figure 7 for Figure 6 A magnified detail of position A in the middle;

[0032] Figure 8 Schematic diagram of the relative position relationship between the bent plate demisting mechanism and the active cleaning mechanism of the present invention;

[0033] Figure 9 Schematic diagram of the bent guide plate in the bent plate demisting mechanism of the present invention being converted into a straight state;

[0034] Figure 10Schematic diagram of the bent guide plate in the bent plate demisting mechanism of the present invention being converted into a bent state;

[0035] Figure 11 A schematic diagram showing the connection relationship between the guide plates of the present invention from a first perspective;

[0036] Figure 12 A schematic diagram showing the connection relationship between the guide plates of the present invention from a second viewing angle;

[0037] Figure 13 for Figure 11 Enlarged detail of position B in the middle;

[0038] Figure 14 for Figure 12 Enlarged detail image of the middle C position;

[0039] Figure 15 This is a schematic diagram of the active cleaning mechanism of the present invention from a first perspective;

[0040] Figure 16 for Figure 15 Enlarged detail image of the middle D position;

[0041] Figure 17 A schematic diagram of the active cleaning mechanism of the present invention from a second perspective;

[0042] Figure 18 This is a schematic diagram of the active cleaning mechanism of the present invention showing a scraper in a horizontal state;

[0043] Figure 19 This is a schematic diagram of the scraper in the active cleaning mechanism of the present invention in a retracted state;

[0044] Figure 20 A schematic diagram of the active cleaning mechanism of the present invention from a third perspective;

[0045] In the figure: 1. demister; 101. exhaust air collecting cover; 1011. exhaust pipe; 102. air intake machine cover; 1021. air intake pipe; 1022. sewage branch; 2. bent plate demister mechanism; 201. bent guide plate; 2011. branch guide plate; 2012. connecting shaft; 2013. first straight gear; 2014. supporting horizontal bar; 3. fixed bracket; 301. worm gear; 302. power input shaft; 303. worm; 304. first rotating motor; 305. first arc-shaped rack; 306. series bracket; 307. Second arc-shaped rack; 308, second bevel gear; 309, transmission rod; 2015, second spur gear; 2016, first bevel gear; 310, third bevel gear; 4, active cleaning mechanism; 401, horizontal guide tube; 4011, slider; 4012, vertical slide rail; 402, cleaning liquid nozzle; 403, scraper; 404, vertical guide tube; 405, cleaning liquid inlet pipe; 406, return spring; 407, limit baffle; 408, limit frame; 5, bar magnet; 501, second rotating motor; 502, threaded rod. DETAILED DESCRIPTION

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0047] Example 1

[0048] Reference Figure 1-20 , an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, including a waste gas input boosting unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit and a solvent storage unit. The waste gas is pressurized by the waste gas input boosting unit and then enters the liquid nitrogen condensation recovery unit. The solvent is cooled and liquefied by heat exchange with liquid nitrogen and enters the solvent storage unit for temporary storage and can be reused. The non-condensable tail gas in the waste gas enters the tail gas treatment optimization unit. The tail gas treatment optimization unit includes a cold recovery heat exchanger and a demister 1. The cold recovery heat exchanger is used to recover the cold in the tail gas and improve the cold utilization rate. The demister 1 is used to remove droplets in the waste gas to ensure the waste gas treatment effect;

[0049] The top and bottom ends of the demister 1 are respectively the exhaust end and the air intake end. The top and bottom ends of the demister 1 are respectively provided with an exhaust air collecting hood 101 and an air intake machine hood 102. The top end of the exhaust air collecting hood 101 is installed with an exhaust pipe 1011, the bottom end of the air intake machine hood 102 is installed with an air intake pipe 1021, and the bottom end of the air intake pipe 1021 is provided with a sewage discharge branch 1022. The interior of the demister 1 is provided with a bent plate defogger mechanism 2 and an active cleaning mechanism 4. The bent plate defogger mechanism 2 is provided with multiple groups of parallel bent guide plates 201. The bent guide plate 201 is composed of multiple sub-guide plates 2011. The sub-guide plates 2011 are hinged head to tail, and the bent guide plates 201 can be converted into a straight state by rotation.

[0050] The exhaust gas enters the demister 1 through the bottom, and passes through the gaps between the adjacent bending guide plates 201. Due to the continuous bending shape of the bending guide plates 201 (refer to Figure 10 As shown), the exhaust gas will be blocked many times during its movement from bottom to top, and the mist droplets in the exhaust gas will be blocked and stay on the bent guide plate 201, thereby achieving the demisting effect, and finally the demisted exhaust gas will flow out from the top;

[0051] When the oil stains on the bent guide plate 201 need to be cleaned, the bent guide plate 201 is converted to a straight state (such as Figure 9 As shown), the surface of the bent guide plate 201 can now be cleaned more conveniently without leaving many blind spots that are difficult to clean due to the bent shape.

[0052] Among them, the exhaust gas input boosting unit is a Roots blower, which is used to boost the collected exhaust gas so that it can smoothly enter the liquid nitrogen condensation unit. The liquid nitrogen condensation recovery unit consists of a liquid nitrogen condenser and a liquid nitrogen mixer. The liquid nitrogen condenser adopts a deep-cold shell and tube structure, and condenses the organic solvent in the exhaust gas into liquid through cooling. The liquid nitrogen mixer is used to ensure that the liquid nitrogen and the exhaust gas are fully mixed to improve the condensation effect.

[0053] Example 2

[0054] Reference Figure 1-20 The difference between this embodiment and embodiment 1 is that fixed brackets 3 are fixed to the inner walls of both sides of the demister 1, connecting shafts 2012 are fixed to the four corners of the branch guide plates 2011, and the first spur gear 2013 is fixed to the connecting shafts 2012. The connecting shafts 2012 on the two branch guide plates 2011 close to each other are rotatably mounted on the fixed brackets 3, and the sides of the two branch guide plates 2011 away from each other are hingedly connected to multiple branch guide plates 2011 in sequence;

[0055] In order to uniformly determine the synchronous rotation of multiple sub-deflectors 2011 connected to the same fixed bracket 3 so as to convert between bending and straightness, the two sub-deflectors 2011 directly connected to the fixed bracket 3 are symmetrically arranged, and the other sub-deflectors 2011 are sequentially connected in series on these two sub-deflectors 2011. The sub-deflectors 2011 are connected end to end and can rotate with each other. A series bracket 306 is fixed on the sub-deflector 2011 at a position away from the fixed bracket 3, and the next sub-deflector 2011 is rotated and connected through the series bracket 306. The first spur gears 2013 on adjacent sub-deflectors 2011 are engaged with each other to ensure stability during mutual rotation. A first arcuate rack 305 is fixed on the fixed bracket 3, and a second arcuate rack 307 is fixed on the series bracket 306. A transmission rod 309 is rotatably installed on 2014, and a transmission shaft is rotatably installed on one side of the support horizontal bar 2014 close to the previous sub-deflector 2011. A second bevel gear 308 is fixed on the connecting shaft 2012 that is rotatably connected to the series bracket 306 on the current sub-deflector 2011. A second spur gear 2015 and a first bevel gear 2016 are fixed on the transmission shaft. The second spur gear 2015 is meshed with the first arc-shaped rack 305 or the second arc-shaped rack 307 on the previous sub-deflector 2011. A third bevel gear 310 is fixed at both ends of the transmission rod 309. The third bevel gear 310 at one end of the transmission rod 309 is meshed with the first bevel gear 2016 on the current sub-deflector 2011, and the third bevel gear 310 at the other end of the transmission rod 309 is meshed with the second bevel gear 308 on the next sub-deflector 2011.

[0056] When one of the deflector plates 2011 connected to the fixed bracket 3 is driven to rotate, the other deflector plate 2011 will rotate synchronously in the opposite direction through the mutual engagement between the first spur gears 2013, so that the two deflector plates 2011 closest to the fixed bracket 3 rotate. When the two deflector plates 2011 rotate, the second spur gear 2015 and the first arc-shaped rack 305 will drive it to rotate, thereby driving the first bevel gear 2016 fixed to the second spur gear 2015 to rotate, and then the third bevel gears 2016 at both ends of the transmission rod 309 are driven to rotate. The transmission of the wheel 310 inputs power to the next-level sub-guide plate 2011, driving the next-level sub-guide plate 2011 to rotate relative to the current-level sub-guide plate 2011, and the two have the same rotation angle, the same rotation speed, and opposite rotation directions. The power will still be transmitted through the rotation of the next transmission rod 309, and drive the next-level sub-guide plate 2011 to rotate synchronously in the opposite direction, so that multiple sub-guide plates 2011 can be driven to rotate synchronously relative to each other through the input of a rotational power, thereby achieving the purpose of rapid conversion between the straight and bent states.

[0057] Among them, a worm gear 301 is rotatably installed on the fixed bracket 3, and the worm gear 301 is fixed to the connecting shaft 2012 on one of the branch guide plates 2011, and a power input shaft 302 is rotated in the defogger 1, and a worm 303 is fixed on the power input shaft 302, and the worm 303 is engaged with the worm gear 301, and the worm 303 is driven to rotate by the first rotating motor 304. When the first rotating motor 304 is turned on, it can drive the power input shaft 302 to rotate, and then the worm 303 is engaged with the worm gear 301 to input the converted form of power to the bending guide plate 201.

[0058] Example 3

[0059] Reference Figure 1-20 The difference between this embodiment and embodiment 1 is that the active cleaning mechanism 4 includes a plurality of horizontal ducts 401, both ends of the horizontal ducts 401 are slidably mounted on vertical slide rails 4012 on the inner wall of the demister 1 via sliders 4011, the horizontal ducts 401 are located above the gap between two adjacent sets of bent guide plates 201, and scrapers 403 are rotatably mounted on both sides of the bottom end of the horizontal ducts 401 via brackets, a return spring 406 is fixed between the top end of the scraper 403 and the bracket, and a limit stopper 407 is fixed to one side of the top end of the scraper 403 on the bracket;

[0060] Due to the pulling force of the return spring 406, the scraper 403 is pulled to maintain a horizontal state and abut against the limit baffle 407. When the bending guide plate 201 is in a straight state (refer to Figure 8 As shown in FIG, during the downward movement of the horizontal guide tube 401, the scraper 403 can just clean the side of the curved guide plate 201 and remove the oil stains.

[0061] Among them, a plurality of cleaning liquid nozzles 402 are fixed to the bottom end of the horizontal conduit 401, a vertical conduit 404 is fixed to the top end of the horizontal conduit 401, a cleaning liquid introduction pipe 405 is installed on the outer wall of the demister 1, and the cleaning liquid introduction pipe 405 is connected to each vertical conduit 404 through a hose to ensure that the horizontal conduit 401 remains connected during the lifting and lowering movement. A limiting frame 408 is fixed on the inner wall of the demister 1, and the limiting frame 408 is provided with two limiting branches, and the two branches are located on both sides above the horizontal conduit 401. The water outlet of the cleaning liquid nozzle 402 faces the bent guide plates 201 on both sides, which can scrape off oil stains while spraying water for cleaning, further improving the cleaning efficiency and cleaning effect. Due to the existence of the limiting frame 408, when there is no need to use the active cleaning mechanism 4, the horizontal conduit 401 is moved to the highest position (refer to Figure 19As shown), at this time, the two limiting branches of the limiting frame 408 will be stuck on both sides of the horizontal guide tube 401 and push the scraper 403 downward to rotate. On the one hand, the inclined scraper 403 will reduce the resistance to the rising gas, and the scraper 403 can be stuck at the liquid outlet position of the cleaning liquid nozzle 402 to protect the cleaning liquid nozzle 402 and prevent oil from entering the interior of the cleaning liquid nozzle 402, causing pollution and damage to the cleaning liquid nozzle 402.

[0062] In order to drive the active cleaning mechanism 4 to move up and down, a bar magnet 5 is installed on the outer wall of the demister 1 for lifting and lowering. A magnetic block is provided on the slider 4011, and the bar magnet 5 and the magnetic block attract each other. When the bar magnet 5 moves up and down, it can drive the horizontal duct 401 to move up and down, and a second rotating motor 501 is fixed on the outer wall of the demister 1. The output shaft of the second rotating motor 501 is fixed with a threaded rod 502, and the threaded rod 502 passes through the bar magnet 5 through a threaded hole. The bar magnet 5 and the magnetic block attract each other and remain relatively prohibited. The second rotating motor 501 can drive the bar magnet 5 to move up and down, thereby driving the active cleaning mechanism 4 to move up and down.

[0063] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0064] In the present invention, unless otherwise expressly specified or limited, terms such as "disposed," "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; they may refer to mechanical connections, direct connections, or indirect connections through an intermediate medium; they may refer to internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0065] The control method of the present invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by a person skilled in the art. The provision of power is also common knowledge in the art. The present invention is mainly used to protect mechanical devices, so the control method and circuit connection are not explained in detail in the present invention.

[0066] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. An integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, comprising a waste gas input pressurization unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit, and a solvent storage unit, characterized in that: The tail gas treatment optimization unit includes a cold recovery heat exchanger and a demister (1); The top and bottom ends of the demister (1) are respectively an exhaust end and an intake end. A bent plate demister mechanism (2) and an active cleaning mechanism (4) are provided inside the demister (1). The bent plate demister mechanism (2) is provided with a plurality of parallel bent guide plates (201). The bent guide plates (201) are composed of a plurality of branch guide plates (211). Each branch guide plate (2011) is hinged at its head and tail, and the bent guide plates (201) can be converted into a straight state by rotation. Fixed brackets (3) are fixed on both inner walls of the demister (1), connecting shafts (2012) are fixed on the four corners of the branch guide plates (2011), and a first straight gear (2013) is fixed on the connecting shafts (2012), wherein the connecting shafts (2012) on the two branch guide plates (2011) close to each other are rotatably mounted on the fixed brackets (3), and a plurality of branch guide plates (2011) are hingedly connected in sequence on the sides of the two branch guide plates (2011) away from each other; A series bracket (306) is fixed on the branch guide plate (211) at a position away from the fixed bracket (3), and the next branch guide plate (211) is rotatably connected via the series bracket (306), and the first spur gears (2013) on adjacent branch guide plates (2011) are meshed with each other, thereby ensuring stability during mutual rotation. A first arc-shaped rack (305) is fixed on the fixed bracket (3), and a second arc-shaped rack (307) is fixed on the series bracket (306); A transmission rod (309) is rotatably mounted on the branch guide plate (2011) via a support bar (2014); a transmission shaft is rotatably mounted on the support bar (2014) on the side close to the previous branch guide plate (2011); a second bevel gear (308) is fixed on a connecting shaft (212) that rotatably connects the next branch guide plate (2011) to the series bracket (306) on the current branch guide plate (2011); a second spur gear (2015) and a first bevel gear (2016) are fixed on the transmission shaft; and a second spur gear (2015) and a first bevel gear (2016) are fixed on the transmission shaft. The gear (215) is meshed with the first arc-shaped rack (305) or the second arc-shaped rack (307) on the previous branch guide plate (2011), and third bevel gears (310) are fixed to both ends of the transmission rod (309). The third bevel gear (310) at one end of the transmission rod (309) is meshed with the first bevel gear (2016) on the current branch guide plate (2011), and the third bevel gear (310) at the other end of the transmission rod (309) is meshed with the second bevel gear (308) on the next branch guide plate (2011).

2. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1, characterized in that: The exhaust gas input boosting unit is a Roots blower, and the liquid nitrogen condensation recovery unit is composed of a liquid nitrogen condenser and a liquid nitrogen mixer. The liquid nitrogen condenser adopts a cryogenic shell and tube structure.

3. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1, characterized in that: The top and bottom ends of the demister (1) are respectively provided with an exhaust air collecting hood (101) and an intake air collecting hood (102); an exhaust pipe (1011) is installed at the top end of the exhaust air collecting hood (101); an intake pipe (1021) is installed at the bottom end of the intake air collecting hood (102); and a sewage discharge branch (1022) is provided at the bottom end of the intake pipe (1021).

4. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1 is characterized in that: A worm gear (301) is rotatably mounted on the fixed bracket (3), the worm gear (301) being fixed to a connecting shaft (2012) on one of the branch guide plates (2011), and a power input shaft (302) is rotatable in the demister (1), a worm (303) being fixed on the power input shaft (302), the worm (303) being meshed with the worm gear (301), and the worm (303) being driven to rotate by a first rotating motor (304).

5. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1 is characterized in that: The active cleaning mechanism (4) comprises a plurality of horizontal ducts (401), both ends of the horizontal ducts (401) being slidably mounted on vertical slide rails (4012) on the inner wall of the demister (1) via sliders (4011), the horizontal ducts (401) being located above the gap between two adjacent sets of bent guide plates (201), and scrapers (403) being rotatably mounted on both sides of the bottom end of the horizontal duct (401) via brackets, a return spring (406) being fixed between the top end of the scraper (403) and the bracket, and a limit baffle (407) being fixed on one side of the top end of the scraper (403) on the bracket.

6. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 5, characterized in that: A plurality of cleaning liquid nozzles (402) are fixed to the bottom end of the horizontal conduit (401), a vertical conduit (404) is fixed to the top end of the horizontal conduit (401), a cleaning liquid introduction pipe (405) is installed on the outer wall of the demister (1), and the cleaning liquid introduction pipe (405) is connected to each vertical conduit (404) through a hose to ensure that the horizontal conduit (401) remains connected during the lifting and lowering movement. A limiting frame (408) is fixed to the inner wall of the demister (1), and the limiting frame (408) is provided with two limiting branches, and the two branches are located on both sides above the horizontal conduit (401).

7. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 6, characterized in that: A bar magnet (5) is mounted on the outer wall of the demister (1) so as to be movable in a lifting manner. A magnetic block is provided on the slider (4011), and the bar magnet (5) and the magnetic block attract each other. When the bar magnet (5) moves up and down, the horizontal guide tube (401) can be driven to move up and down. A second rotating motor (501) is fixed on the outer wall of the demister (1), and a threaded rod (502) is fixed to the output shaft of the second rotating motor (501). The threaded rod (502) passes through the bar magnet (5) through a threaded hole.

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