Integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system

Abstract

The invention discloses an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, and relates to the technical field of waste gas treatment, the system comprises a waste gas input pressurization unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit and a solvent storage unit, the tail gas treatment optimization unit comprises a cooling capacity recovery heat exchanger and a demister; the top end and the bottom end of the demister are respectively an exhaust end and an air inlet end, and a bent plate demisting mechanism and an active cleaning mechanism are arranged in the demister. The whole system organically combines the waste gas input pressurization unit, the liquid nitrogen condensation recovery unit, the tail gas treatment optimization unit and the solvent storage unit, the integrated process from waste gas input to solvent recovery and tail gas treatment is achieved, the design is reasonable, the structure is compact, the overall operation efficiency and stability of the system are improved, and the service life of the system is prolonged. And the method has relatively high social use value and application prospect.

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 field of industrial production, the control of volatile organic pollutants (VOCs) has always been the focus and difficulty of environmental protection work. For enterprises that use organic solvents as raw and auxiliary materials, the organic waste gas emitted during their production process brings many challenges to the environment and corporate development.

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

[0004] Traditional organic waste gas treatment processes have many drawbacks when dealing with such waste gas. For example, although the adsorption method can absorb some organic matter, the adsorbent is easily saturated and requires frequent regeneration, which not only increases the operating cost, but may also cause waste gas treatment to fail to meet standards due to incomplete adsorption; although the combustion method can decompose organic matter, it consumes a lot of energy, and secondary pollutants such as nitrogen oxides may be produced during high-temperature combustion, further increasing the environmental burden. In addition, some traditional processes have low recovery efficiency for organic matter in waste gas, making it difficult to achieve effective recycling of resources.

[0005] The demister in the traditional waste gas treatment system is inconvenient to clean and maintain when dealing with such complex organic waste gas. Due to the complex composition of organic waste gas, it is easy to form stubborn oil and dirt inside the demister, and the structural design of the traditional demister makes it difficult to reach every corner during cleaning, resulting in incomplete cleaning. Frequent manual cleaning not only consumes a lot of manpower, material resources and time, but may also damage the demister due to improper operation, increase maintenance costs and downtime, and affect the normal production of the enterprise. 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: 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; The top and bottom ends of the demister are respectively the exhaust end and the air inlet end. The interior of the demister is provided with a bent plate defogger mechanism and an active cleaning mechanism. The bent plate defogger mechanism is provided with a plurality of groups of parallel arranged bent guide plates. The bent guide plates are composed of a plurality of sub-guide plates, each of which is hinged end to end, and the bent guide plates can be converted into a straight state by rotation.

[0008] 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.

[0009] Preferably, the top and bottom ends of the demister are respectively provided with an exhaust air collecting hood and an air intake machine hood, an exhaust pipe is installed at the top of the exhaust air collecting hood, an air intake pipe is installed at the bottom end of the air intake machine hood, and a sewage discharge branch is provided at the bottom end of the air intake pipe.

[0010] 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 branch guide plates, and the first straight gear is fixed on the connecting shafts, wherein the connecting shafts on the two branch guide plates close to each other are rotatably mounted on the fixed brackets, and multiple branch guide plates are hinged in sequence on the sides of the two branch guide plates away from each other.

[0011] 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 rotatably connected through the series bracket, and the first spur gears on adjacent branch guide plates are meshed 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.

[0012] Preferably, a transmission rod is rotatably installed on the sub-deflector plate through a supporting cross bar, and a transmission shaft is rotatably installed on the side of the supporting cross bar close to the previous sub-deflector plate, and a second bevel gear is fixed on the connecting shaft that is rotatably connected to the series bracket on the current sub-deflector plate for the next sub-deflector plate, and a second spur gear and a first bevel gear are fixed on the transmission shaft, and the second spur gear is meshed with the first arc rack or the second arc rack on the previous sub-deflector plate, and third bevel gears are fixed at both ends of the transmission rod, and the third bevel gear at one end of the transmission rod is meshed with the first bevel gear on the current sub-deflector plate, 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 plate.

[0013] 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 defogger, a worm is fixed on the power input shaft, the worm is meshed with the worm gear, and the worm is driven to rotate by the first rotating motor.

[0014] 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 groups 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.

[0015] 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, 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, and a limit frame is fixed to the inner wall of the demister, the limit frame is provided with two limit branches, and the two branches are located on both sides above the horizontal conduit.

[0016] Preferably, a bar magnet is movably installed on the outer wall of the demister, a magnetic block is provided on the slider, and the bar magnet and the magnetic block attract each other, and 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.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Efficient defogger and cleaning function: A bent plate defogger mechanism is set inside the defogger. Its bent guide plate is composed of multiple branch guide plates hinged at the head and tail, which can be switched between bent and straight states. In the bent state, it can effectively block the droplets in the exhaust gas and has a good defogger effect; when cleaning is required, it can be switched to a straight state for easy cleaning and to avoid cleaning dead corners. At the same time, the active cleaning mechanism can automatically clean the bent guide plate, the cleaning liquid nozzle on the horizontal duct sprays water for cleaning, and the scraper scrapes off oil stains to improve cleaning efficiency and effect. In addition, the limit frame can protect the cleaning liquid nozzle in the non-cleaning state and extend its service life.

[0018] 2. Good structural stability and transmission coordination: By setting 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 rotational power input, thereby realizing a fast and stable conversion of the bent deflector between the straight and bent states.

[0019] 3. Advantages of cold recovery and system integration: The cold recovery heat exchanger in the tail gas treatment optimization unit can recover the cold in the tail gas and improve the utilization rate of cold. The whole system organically combines the waste gas input boosting unit, liquid nitrogen condensation recovery unit, tail gas treatment optimization unit and solvent storage unit, realizing an integrated process from waste gas input to solvent recovery and tail gas treatment. It has a reasonable design and compact structure, which improves the overall operating efficiency and stability of the system and has high social use value and application prospects.

[0020] 4. Automated cleaning and convenient operation: The horizontal guide tube of the active cleaning mechanism is magnetically connected to the bar magnet through the 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

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 creative work.

[0022] Figure 1 is a flow chart of the present invention; Figure 2 A three-dimensional diagram of a demister of the present invention; Figure 3 It is a front view of the demister of the present invention; Figure 4 It is a left side view of the present invention; Figure 5 is a three-dimensional cross-sectional view of the present invention; Figure 6 It is a schematic diagram of the matching relationship between the worm wheel and the worm of the present invention; Figure 7 for Figure 6 A zoomed-in detail of position A in the middle; Figure 8 A schematic diagram of the relative position relationship between the bent plate demisting mechanism and the active cleaning mechanism of the present invention; Fig. 9 It is a schematic diagram of the bent guide plate in the bent plate demisting mechanism of the present invention being converted into a straight state; Fig.10 It is a schematic diagram of the bending guide plate in the bent plate demisting mechanism of the present invention being converted into a bent state; Fig.11 A schematic diagram showing the connection relationship between the guide plates of the present invention from a first viewing angle; Fig.12 A schematic diagram of the connection relationship between the guide plates of the present invention from a second viewing angle; Fig.13 for Fig.11 Enlarged detail of position B in the middle; Fig.14 for Fig.12 Enlarged detail image of the middle C position; Fig.15 It is a schematic diagram of the active cleaning mechanism of the present invention from a first perspective; Fig.16 for Fig.15 Enlarged detail image of the middle D position; Fig.17 A schematic diagram of the active cleaning mechanism of the present invention from a second viewing angle; Fig.18 It is a schematic diagram of the scraper in the active cleaning mechanism of the present invention being in a horizontal state; Fig.19 It is a schematic diagram of the scraper in the active cleaning mechanism of the present invention in a retracted state; Fig. 20 A schematic diagram of the active cleaning mechanism of the present invention from a third viewing angle; In the figure: 1. defogger; 101. exhaust air collecting hood; 1011. exhaust pipe; 102. air intake machine hood; 1021. air intake pipe; 1022. sewage branch; 2. bent plate defogger 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 rack; 306. series bracket; 307. The second arc rack; 308, the second bevel gear; 309, the transmission rod; 2015, the second spur gear; 2016, the first bevel gear; 310, the third bevel gear; 4, the active cleaning mechanism; 401, the horizontal guide tube; 4011, the slider; 4012, the vertical slide rail; 402, the cleaning liquid nozzle; 403, the scraper; 404, the vertical guide tube; 405, the cleaning liquid inlet pipe; 406, the reset spring; 407, the limit baffle; 408, the limit frame; 5, the bar magnet; 501, the second rotating motor; 502, the threaded rod. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0024] Example 1 Reference Figure 1-20 , an integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system, including a waste gas input booster unit, a liquid nitrogen condensation recovery unit, a tail gas treatment optimization unit and a solvent storage unit. The waste gas enters the liquid nitrogen condensation recovery unit after being pressurized by the waste gas input booster unit, and enters the solvent storage unit for temporary storage through heat exchange with liquid nitrogen to cool the solvent liquefy, which 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; The top and bottom of the demister 1 are the exhaust end and the intake end respectively. The top and bottom of the demister 1 are respectively provided with an exhaust air collecting hood 101 and an intake machine hood 102. The top of the exhaust air collecting hood 101 is provided with an exhaust pipe 1011. The bottom of the intake machine hood 102 is provided with an intake pipe 1021. The bottom of the 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 a plurality of parallel bent guide plates 201. The bent guide plate 201 is composed of a plurality of branch guide plates 2011. Each branch guide plate 2011 is hinged head-to-tail, and the bent guide plate 201 can be converted into a straight state by rotation. The exhaust gas enters the demister 1 through the bottom, and passes through the gaps between the adjacent curved guide plates 201. Due to the continuous curved shape of the curved guide plates 201 (refer to Fig.10 As shown in FIG. 2 ), 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 effect of demisting, and finally the demisted exhaust gas will flow out from the top; When the oil stain on the curved guide plate 201 needs to be cleaned, the curved guide plate 201 is converted to a straight state (such as Fig. 9 As shown), the surface of the curved guide plate 201 can now be cleaned more conveniently without leaving many blind spots that are difficult to clean due to the curved shape.

[0025] 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. The organic solvent in the exhaust gas is condensed into liquid by 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.

[0026] Example 2 Reference Figure 1-20The difference between this embodiment and the embodiment 1 is that a fixing bracket 3 is fixed on both inner walls of the demister 1, a connecting shaft 2012 is fixed on the four corners of the branch guide plate 2011, and a first straight gear 2013 is fixed on the connecting shaft 2012, wherein the connecting shafts 2012 close to each other on the two branch guide plates 2011 are rotatably mounted on the fixing bracket 3, and a plurality of branch guide plates 2011 are hinged in sequence on the sides of the two branch guide plates 2011 away from each other; In order to uniformly determine the synchronous rotation of multiple sub-guide plates 2011 connected to the same fixed bracket 3 so as to switch between bending and straightness, the two sub-guide plates 2011 directly connected to the fixed bracket 3 are symmetrically arranged, and the other sub-guide plates 2011 are sequentially connected in series to the two sub-guide plates 2011. The sub-guide plates 2011 are connected end to end and can rotate with each other. A series bracket 306 is fixed on the position of the sub-guide plate 2011 away from the fixed bracket 3, and the next sub-guide plate 2011 is rotatably connected through the series bracket 306, and the first spur gears 2013 on adjacent sub-guide plates 2011 are meshed with each other to ensure stability when rotating with each other. 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. 2014 is rotatably mounted with a transmission rod 309, a transmission shaft is rotatably mounted on one side of the support bar 2014 close to the previous branch guide plate 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 branch guide plate 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 branch guide plate 2011, and third bevel gears 310 are 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 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; When one of the guide plates 2011 connected to the fixed bracket 3 is driven to rotate, the other guide plate 2011 will rotate synchronously in the opposite direction through the mutual meshing between the first spur gears 2013, so that the two guide plates 2011 closest to the fixed bracket 3 rotate. When the two guide 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.

[0027] 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 meshed 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 meshed with the worm wheel 301 to input the power of the conversion form to the bending guide plate 201.

[0028] Example 3 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 the vertical slide rails 4012 on the inner wall of the demister 1 through 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 through brackets, a return spring 406 is fixed between the top end of the scraper 403 and the bracket, and a limit baffle 407 is fixed on one side of the top end of the scraper 403 on the bracket; 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 curved guide plate 201 is in a straight state (refer to Figure 8 As shown in FIG. 4 ), during the downward movement of the horizontal conduit 401, the scraper 403 can just clean the side of the curved guide plate 201 and scrape off the oil stains.

[0029] 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 Fig.19 As shown), at this time, the two limiting branches of the limiting frame 408 will be stuck on both sides of the horizontal conduit 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.

[0030] 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. A threaded rod 502 is fixed on the output shaft of the second rotating motor 501. 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.

[0031] 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 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0032] In the present invention, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] 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 technicians in this field. The provision of power is also common knowledge in this field. The present invention is mainly used to protect mechanical devices, so the present invention will no longer explain the control method and circuit connection in detail.

[0034] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope 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 exhaust gas treatment optimization unit comprises 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 groups of parallel arranged bent guide plates (201). The bent guide plates (201) are composed of a plurality of branch guide plates (2011). Each branch guide plate (2011) is hinged end to end, and the bent guide plates (201) can be converted into a straight state by rotation.

2. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1 is 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 is 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 machine 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 machine 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: Fixed brackets (3) are fixed on the inner walls on both sides of the demister (1), connecting shafts (2012) are fixed on the four corners of the branch guide plates (2011), and a first spur gear (2013) is fixed on the connecting shafts (2012), wherein the connecting shafts (2012) on 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.

5. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 4 is characterized in that: 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 (2011) 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 when rotating with each other, and 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).

6. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 5 is characterized by: A transmission rod (309) is rotatably mounted on the branch guide plate (2011) via a support cross bar (2014); a transmission shaft is rotatably mounted on the support cross bar (2014) on a 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) meshes with the first arc-shaped rack (305) or the second arc-shaped rack (307) on the previous branch guide plate (2011); 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) meshes 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) meshes with the second bevel gear (308) on the next branch guide plate (2011).

7. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 6 is characterized by: 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 rotatably mounted in the demister (1), a worm (303) is fixed on the power input shaft (302), the worm (303) is meshed with the worm gear (301), and the worm (303) is driven to rotate by a first rotating motor (304).

8. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 1 is characterized by: 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.

9. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 8, 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), the cleaning liquid introduction pipe (405) and each vertical conduit (404) are connected via a hose to ensure that the horizontal conduit (401) remains connected during the process of lifting and lowering, and a limiting frame (408) is fixed to the inner wall of the demister (1), the limiting frame (408) is provided with two limiting branches, and the two branches are located on both sides above the horizontal conduit (401).

10. The integrated liquid nitrogen cryogenic waste gas treatment and solvent recovery system according to claim 9, characterized in that: A bar magnet (5) is movably mounted on the outer wall of the demister (1), a magnetic block is provided on the slider (4011), and the bar magnet (5) and the magnetic block attract each other, so that when the bar magnet (5) moves up and down, the horizontal guide tube (401) can be driven to move up and down, and 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), and the threaded rod (502) passes through the bar magnet (5) through a threaded hole.

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