Vacuum exhaust system of double-screw extruder for processing oxygen absorbent

Abstract

The invention relates to a vacuum exhaust system of a double-screw extruder for processing an oxygen absorbent, and belongs to the technical field of tail gas treatment, the vacuum exhaust system comprises a vacuum pipe and a shell, the vacuum pipe penetrates through the shell, the air inlet end of the vacuum pipe is connected with an exhaust port of the extruder, and the exhaust end of the vacuum pipe is connected with a vacuum pump; the exhaust end of the vacuum pump is connected with a first gas treatment device, the first gas treatment device is used for removing soluble gas in the tail gas, the exhaust end of the first gas treatment device is connected with a second gas treatment device, and the second gas treatment device is used for removing residual small organic molecules in the tail gas; the shell is connected with a vortex tube, the cold air discharge end of the vortex tube is communicated with an inner cavity of the shell, the air inlet end of the vortex tube is connected with a pressure pump, a liquid collecting sleeve is installed in the shell, the liquid collecting sleeve is communicated with the vacuum tube, and the liquid collecting sleeve is used for collecting condensate formed after tail gas is condensed in the vacuum tube. The device has the effects of realizing stable extraction of gas and reducing the damage of tail gas to the vacuum pump.

Description

Technical Field

[0001] The present application relates to the technical field of tail gas treatment, and in particular to a vacuum exhaust system of a twin-screw extruder used for processing oxygen absorbents. Background Art

[0002] Oxygen absorbers are widely used in the packaging of food, pharmaceuticals, electronic components, and other products to absorb residual oxygen in a closed environment, thereby extending the product's shelf life. The main components of oxygen absorbers are often a mixture of easily oxidizable metal powders (such as iron powder) and additives (such as activated carbon and inorganic salts). During processing, they are continuously mixed and granulated using a twin-screw extruder. However, because oxygen absorber systems often contain volatile additives or organic solvents, the extrusion process easily generates large amounts of low-molecular-weight byproducts, water vapor, and residual solvents. If not promptly expelled, these products can not only cause holes, adhesion, or wire breakage, but can also corrode equipment and affect molding stability.

[0003] To this end, conventional techniques typically incorporate a vacuum vent in the middle or end of the twin-screw extruder barrel. A vacuum pump is then used to extract the high-temperature, high-humidity gases, which are then purified using an exhaust condenser or adsorption tower. Within this vacuum exhaust system, a water ring vacuum pump is often used to evacuate the extruder's exhaust port. This pump uses water as its working medium, forming a water ring with a rotating impeller within the pump body. This pump continuously pumps air through the volumetric changes in the gas-water mixing chamber. The extracted gas then passes through the vacuum pump and enters the condenser for condensation.

[0004] However, during the processing of oxygen absorbers, since the exhaust contains a large amount of high-temperature water vapor, low-molecular organic matter, residual organic solvents and acidic small molecular gases, once these components enter the water ring pump with the air flow, they are very likely to condense and dissolve in the water ring medium and mix into the water, which in turn leads to the continuous accumulation of condensate and organic impurities in the water ring, which will cause the working fluid to deteriorate. The condensed components are corrosive (such as acidic small molecules, alcohol ester residues), which react with water to form an acidic solution, corrode the metal structure of the pump body, or form deposits and scaling. A large amount of condensate entering the pump cavity will change the fluid state, increase the gas-liquid friction in the pump, reduce the system vacuum, and even cause air blockage or blockage, reducing the pumping efficiency, and requiring frequent replacement of the working fluid.

[0005] Moreover, traditional condensing equipment cannot be directly installed at the air inlet end of the vacuum pump for early condensation, because traditional condensers are generally large in size, complex in structure, with long internal gas channels and large flow resistance. Once installed at the front end of the vacuum pump, a significant pressure drop will be formed in the exhaust path, hindering the vacuum pump from quickly establishing a low-pressure zone at the exhaust port of the extruder, thereby weakening the exhaust capacity, making it difficult to remove volatile components in time during the extrusion process, and easily causing exhaust stagnation or even air backflow. Summary of the Invention

[0006] In order to achieve stable extraction of gas and reduce the damage of exhaust gas to the vacuum pump, the present application provides a vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent.

[0007] The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbents provided in this application adopts the following technical solution: A vacuum exhaust system for a twin-screw extruder used for processing oxygen absorbents, comprising a vacuum tube and a housing. The vacuum tube passes through the housing, and the air inlet end of the vacuum tube is connected to the exhaust port of the extruder. The exhaust end of the vacuum tube is connected to a vacuum pump, and the exhaust end of the vacuum pump is connected to a first gas treatment device. The first gas treatment device is used to remove soluble gases in the exhaust gas. The exhaust end of the first gas treatment device is connected to a second gas treatment device. The second gas treatment device is used to remove residual organic small molecules in the exhaust gas. The shell is connected to a vortex tube, the cold air discharge end of the vortex tube is connected to the inner cavity of the shell, the air inlet end of the vortex tube is connected to a pressure pump, and a liquid collecting sleeve is installed in the shell, the liquid collecting sleeve is connected to the vacuum tube, and the liquid collecting sleeve is used to collect condensate formed after the exhaust gas condenses in the vacuum tube.

[0008] By adopting the above technical solution, the gas discharged from the extruder passes through the vacuum tube, vacuum pump, first gas treatment device, and second gas treatment device in sequence under the extraction action of the vacuum pump, and finally discharged to the outside. When the gas enters the vacuum tube section inside the shell, the vortex tube discharges cold air into the shell, causing the gas to condense in the vacuum tube, condensing the moisture, low-molecular byproducts, and residual solvents in the gas. The gas then passes through the first gas treatment device, which removes acidic gases and easily soluble small molecules in the gas, and then passes through the second gas treatment device to adsorb VOCs in the gas and remove the tail gas.

[0009] The use of a shell plus a vortex tube to directly condense on the vacuum tube is equivalent to integrating the condensing equipment on the vacuum tube, that is, condensation is completed during the normal gas transportation process. The compact layout enables condensation and transportation to proceed simultaneously, significantly shortening the exhaust path, reducing air resistance, and ensuring that the vacuum pump can quickly establish a stable low-pressure environment at the exhaust port; The vortex tube's output cold air temperature can reach below -10°C, far lower than the temperatures of conventional cooling water or air cooling in traditional condensing units, resulting in greater instantaneous condensation capabilities. The high-temperature exhaust gas, directly exposed to the cold air within the vacuum tube, rapidly separates out water vapor, low-molecular byproducts, and residual organic solvents. This ensures sufficient condensation efficiency even without increasing the length of the condensation path, mitigating the risk of gas contamination and corrosion to the vacuum pump at the source. This allows the condensation process to be pre-positioned at the vacuum pump's exhaust port, minimizing exhaust gas damage to the vacuum pump while ensuring effective condensation and stable gas extraction.

[0010] Optionally, the vacuum tube includes an air intake pipe, a U-shaped connecting pipe and an exhaust pipe, the U-shaped connecting pipe is located in the shell, one end of the U-shaped connecting pipe is connected to the air intake pipe, and the other end of the U-shaped connecting pipe is connected to the exhaust pipe, a drain port is provided at the bottom of the U-shaped connecting pipe, and the liquid collecting sleeve is threadedly and sealedly connected to the drain port.

[0011] By adopting this technical solution, a U-shaped connecting pipe is installed inside the housing, forming a condensation zone for the exhaust gas within the vacuum tube section. Its curved structure allows the condensate to naturally settle and gather at the bottom of the U during gas flow. It is then introduced into the collection sleeve through the drain port, achieving centralized collection and targeted discharge of the condensate. This effectively prevents the condensate from flowing back into the extruder with the airflow and contaminating the material. It also prevents the condensate from being drawn into the vacuum pump, reducing the risk of internal pump corrosion and gas-liquid shock, thereby maintaining system vacuum stability and equipment life.

[0012] Optionally, an installation port is provided on the U-shaped connecting pipe, and the installation port is arranged opposite to the drain port. A sealing cover is threadedly sealed at the installation port, and a through hole is provided in the sealing cover. An electric cylinder is installed in the shell, and one end of the push rod of the electric cylinder passes through the through hole and is installed with a liquid level sensor. The liquid collecting sleeve is connected to a drain pipe, and the drain pipe extends out of the shell and is installed with a first solenoid valve. When the condensate submerges the liquid level sensor, the first solenoid valve opens, and a sealing ring is installed at the through hole.

[0013] By adopting this technical solution, a liquid level sensor monitors the condensate level within the liquid collection sleeve, and an electric cylinder controls the sensor's height, enabling adjustable control of the liquid level. Changes in the condensate storage volume directly alter the effective gas flow space within the U-shaped connecting tube and the liquid collection sleeve, thereby dynamically adjusting the volume of the gas discharge path within the vacuum tube.

[0014] Furthermore, when the exhaust flow of the extruder fluctuates greatly, the liquid level can be adjusted to adjust the exhaust chamber volume, thereby buffering the flow shock. When the exhaust is at high humidity or there is a lot of condensate, the liquid level can be automatically lowered to avoid a significant reduction in the cross-sectional area of the gas channel causing gas blockage or liquid hammer. In the early stage of exhaust or low flow stage, the chamber volume can be reduced by appropriately increasing the liquid level, which helps the vacuum pump to quickly establish a low-pressure area and improve the pumping response efficiency.

[0015] Optionally, there are several vortex tubes, and the hot gas exhaust ends of several of the vortex tubes are commonly connected to a first diversion pipe. The main pipe section of the first diversion pipe is arranged around the extruder feed hopper, and the shell is connected to a second diversion pipe. Each branch pipe section of the second diversion pipe corresponds one-to-one to the electrical control box of the extruder.

[0016] By adopting the above technical solution, the hot gas is discharged to the first diversion pipe, which can achieve constant temperature heating of the feed port, effectively preventing the oxygen absorber raw materials from bridging, clogging and other problems due to moisture or condensation due to temperature difference during the feeding process; and even if the cold air in the shell absorbs heat through condensation, the gas temperature is still low, and can be discharged to the electrical control box through the second diversion pipe for cooling, realizing the utilization of hot gas and multi-stage utilization of cold air.

[0017] Optionally, the first diversion pipe is also connected to a first branch pipe, the first branch pipe is connected to a circulating water tank, a circulating flow channel is opened in the side wall of the liquid collecting sleeve, the discharge end of the circulating water tank is connected to the liquid inlet end of the circulating flow channel through an inlet pipe, the discharge end of the circulating flow channel is connected to the liquid inlet end of the circulating water tank through a drain pipe, the liquid in the circulating water tank and the circulating flow channel forms a circulating flow through a water pump, and the first branch pipe is connected to the circulating water tank.

[0018] By adopting the above technical solution, part of the hot air can be diverted through the first branch pipe to the circulating water tank to heat the water inside it. The water in the circulating water tank can be transported to the circulating flow channel through the water pump, thereby keeping the condensate warm and avoiding the situation where the temperature inside the shell is too low, causing the condensate to freeze and be unable to be discharged smoothly.

[0019] Optionally, an exhaust one-way valve is provided on the circulating water tank, the first branch pipe is connected to a serpentine pipe, a plurality of exhaust holes are opened on the serpentine pipe, the serpentine pipe extends into the liquid in the circulating water tank, and the first branch pipe is installed with a second solenoid valve.

[0020] By adopting the above technical solution, the second solenoid valve can control whether the hot air is discharged into the circulating water tank. When the water temperature in the circulating water tank reaches the insulation temperature, the second solenoid valve is closed. When the water in the circulating water tank needs to be heated, the second solenoid valve is opened, and the hot air enters the serpentine pipe and is discharged from multiple exhaust holes, so that the water can fully exchange heat with the hot air, thereby achieving a rapid increase in water temperature. When the air pressure in the circulating water tank reaches a certain value, the exhaust one-way valve will automatically open to exhaust.

[0021] Optionally, the outer peripheries of the liquid collecting sleeve, the water inlet pipe and the drain pipe are all provided with a thermal insulation layer, and the thermal insulation layer is used to reduce the heat exchange between the liquid collecting sleeve, the water inlet pipe and the drain pipe and the cold air in the shell.

[0022] By adopting the above technical solution, the design of the thermal insulation layer can prevent the warm water from being cooled by the cold air in the shell, thereby ensuring the thermal insulation effect of the liquid collecting sleeve.

[0023] Optionally, the second branch pipe is connected to a second branch pipe, and the exhaust end of the second branch pipe is arranged toward the vacuum pump.

[0024] By adopting the above technical solution, cold air can cool the vacuum pump through the second branch pipe.

[0025] Optionally, the first gas treatment device includes a spray tower and a gas-liquid separator, and the second gas treatment device includes an activated carbon adsorption tower. The air inlet of the spray tower is connected to the exhaust end of the vacuum pump, the packing layer material in the spray tower is a ball ring, and the spray washing liquid of the spray tower adopts an alkaline washing liquid. The exhaust end of the spray tower is connected to the air inlet end of the gas-liquid separator, the exhaust end of the gas-liquid separator is connected to the air inlet end of the activated carbon adsorption tower, and the discharge end of the gas-liquid separator is connected to the circulating liquid tank of the spray tower.

[0026] Optionally, the shell includes a first shell segment and a second shell segment, and the first shell segment and the second shell segment are both provided with semicircular holes, and the semicircular holes of the first shell segment correspond one-to-one to the semicircular holes of the second shell segment. A plug-in plate is provided on the splicing surface of the first shell segment facing the second shell segment, and the plug-in plate is arranged along the circumference of the first shell segment. A plug-in ring groove is provided on the splicing surface of the second shell segment facing the first shell segment, and the plug-in ring groove is opened along the circumference of the second shell segment. A sealing gasket is provided in the plug-in ring groove along its circumference. When the plug-in plate is inserted into the plug-in ring groove and pressed against the sealing gasket, the first shell segment and the second shell segment are spliced, and the corresponding semicircular holes are spliced to form a pipe mouth adapted to the vacuum tube.

[0027] By adopting the above technical solution, using the upper and lower shell segment splicing structure and positioning through the plug-in plate and the plug-in ring groove, rapid assembly and disassembly can be achieved, which facilitates the cleaning, maintenance or replacement of internal components such as the vacuum tube and liquid collection sleeve during operation, significantly improving the maintenance convenience of the equipment.

[0028] In summary, this application includes at least one of the following beneficial technical effects: 1. The use of a shell plus a vortex tube to directly condense on the vacuum tube is equivalent to integrating the condensing equipment on the vacuum tube, that is, condensation is completed during the normal gas transportation process. The compact layout enables condensation and transportation to proceed simultaneously, significantly shortening the exhaust path, reducing air resistance, and ensuring that the vacuum pump can quickly establish a stable low-pressure environment at the exhaust port; 2. The vortex tube's output cold air temperature can reach below -10°C, far lower than the temperature level of conventional cooling water or air cooling in traditional condensing devices, and has a stronger instantaneous condensation capability. The high-temperature exhaust gas is directly acted upon by the cold air in the vacuum tube, which can quickly precipitate water vapor, low-molecular by-products, and residual organic solvents. Even without increasing the length of the additional condensation path, sufficient condensation efficiency can still be guaranteed, reducing the risk of gas contamination and corrosion to the vacuum pump at the source. This achieves the goal of pre-positioning the condensation process at the exhaust end of the vacuum pump, reducing the damage to the vacuum pump caused by exhaust gas, while ensuring the condensation effect and stable gas extraction. 3. A liquid level sensor is used to monitor the condensate level in the liquid collection sleeve, and the height setting of the liquid level sensor is controlled by an electric cylinder to achieve adjustable control of the liquid level. When the exhaust flow of the extruder fluctuates greatly, the exhaust chamber volume can be adjusted by adjusting the liquid level, thereby buffering the flow shock. When exhausting at high humidity or when there is a lot of condensate, the liquid level can be automatically lowered to avoid a significant reduction in the cross-sectional area of the gas channel, causing air blockage or liquid hammer. In the early stage of exhaust or low flow, by appropriately raising the liquid level and reducing the chamber volume, the vacuum pump can quickly establish a low-pressure zone and improve the pumping response efficiency. 4. The hot gas is discharged to the first diversion pipe, which can achieve constant temperature heating of the feed port, effectively preventing the oxygen absorber raw materials from bridging and clogging due to moisture or condensation due to temperature differences during the feeding process. Even though the cold air in the shell absorbs heat through condensation, the gas temperature is still low and can be discharged to the electric control box through the second diversion pipe for cooling, realizing the utilization of hot gas and multi-stage utilization of cold air. 5. Part of the hot air can be diverted through the first branch pipe to the circulating water tank to heat the water inside it. The water in the circulating water tank can be transported to the circulating flow channel through the water pump, thereby keeping the condensate warm and avoiding the situation where the temperature inside the shell is too low and the condensate is frozen and cannot be discharged smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1It is a structural diagram of a vacuum tube according to an embodiment of the present application.

[0030] Figure 2 yes Figure 1 Enlarged schematic diagram of part A.

[0031] Figure 3 It is a structural diagram of the first solenoid valve and the water pump used in an embodiment of the present application.

[0032] Figure 4 It is a schematic diagram of the overall structure of an embodiment of the present application.

[0033] Figure 5 It is a structural schematic diagram of the shell used to illustrate the embodiment of the present application.

[0034] Figure 6 yes Figure 5 Schematic diagram of the enlarged portion B.

[0035] Explanation of reference numerals: 1. vacuum tube; 11. air inlet pipe; 12. U-shaped connecting pipe; 121. liquid discharge port; 122. mounting port; 123. blocking cover; 1231. through hole; 1232. sealing ring; 13. exhaust pipe; 14. electric cylinder; 15. liquid level sensor; 2. housing; 21. second diverter pipe; 22. second branch pipe; 23. first housing section; 231. plug-in plate; 24. second housing section; 241. plug-in ring groove; 242. sealing gasket; 25. semicircular hole; 3. liquid collecting sleeve; 31. Drain pipe; 32. First solenoid valve; 33. Circulating flow channel; 41. Water inlet pipe; 42. Drain pipe; 43. Water pump; 44. Circulating water tank; 45. Insulation layer; 5. Vortex tube; 51. Pressure pump; 52. First diversion pipe; 53. First branch pipe; 54. Second solenoid valve; 55. Serpentine tube; 551. Exhaust hole; 56. Exhaust check valve; 6. First gas treatment device; 61. Spray tower; 62. Gas-liquid separator; 7. Second gas treatment device; 71. Activated carbon adsorption tower; 8. Vacuum pump. DETAILED DESCRIPTION

[0036] The following is combined with Figure 1-6 This application is described in further detail.

[0037] The embodiments of the present application disclose a vacuum exhaust system of a twin-screw extruder for processing oxygen absorbents.

[0038] like Figure 1The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbents includes a vacuum tube 1 and a housing 2. The vacuum tube 1 includes an air inlet pipe 11, a U-shaped connecting pipe 12, and an exhaust pipe 13. One end of the U-shaped connecting pipe 12 is flange-connected to the air inlet pipe 11, and the other end of the U-shaped connecting pipe 12 is flange-connected to the exhaust pipe 13. The air inlet pipe 11, the U-shaped connecting pipe 12, and the exhaust pipe 13 are combined to form an S-shaped pipe. The air inlet pipe 11 is connected to the exhaust port of the extruder, and the exhaust pipe 13 is connected to a vacuum pump 8.

[0039] like Figure 1 and Figure 2 The bottom of the U-shaped connecting tube 12 is provided with a drain port 121, and the U-shaped connecting tube 12 is connected to the liquid collecting sleeve 3 through the drain port 121. The liquid collecting sleeve 3 is threadedly sealed with the drain port 121. The specific threaded sealing connection method is that the drain port 121 is a stepped port, and a sealing gasket is provided at the stepped groove of the drain port 121. The opening of the liquid collecting sleeve 3 is threadedly connected in the drain port 121 and tightly pressed against the sealing gasket. The U-shaped connecting tube 12 is provided with a mounting port 122, and the mounting port 122 is arranged opposite to the drain port 121. A sealing cap 123 is threadedly sealed with the mounting port 122. The threaded sealing connection method between the sealing cap 123 and the mounting port 122 and the threaded sealing connection method between the liquid collecting sleeve 3 and the drain port 121 are the same. The sealing cap 123 is provided with a through hole 1231, and a sealing ring 1232 is installed at the through hole 1231.

[0040] U-shaped connecting tube 12 and liquid collection sleeve 3 are installed within housing 2. An electric cylinder 14 is mounted on the top of housing 2. The electric push rod of electric cylinder 14 passes through through-hole 1231 and is connected to a liquid level sensor 15. A drain pipe 31 is connected to liquid collection sleeve 3, extending out of housing 2. A first solenoid valve 32 is mounted on the end of drain pipe 31 extending out of housing 2. When the condensate submerges the liquid level sensor 15, first solenoid valve 32 opens.

[0041] like Figure 1 and Figure 3 A circulation channel 33 is defined within the peripheral wall of the liquid collection sleeve 3. The liquid inlet of the circulation channel 33 is connected to an inlet pipe 41, and the liquid outlet of the circulation channel 33 is connected to a drain pipe 42. The inlet pipe 41, the circulation channel 33, the drain pipe 42, and the drain pipe 31 are all covered with an insulation layer 45, which may be made of NBP / PVC foam. The inlet pipe 41 is connected to a water pump 43, which is connected to a circulating water tank 44, which is connected to the drain pipe 42.

[0042] like Figure 1 、 Figure 3 and Figure 4Several vortex tubes 5 are mounted on the housing 2. In the embodiment of the present application, there are four vortex tubes 5. The cold air end of the vortex tube 5 extends into the housing 2. A pressure pump 51 is mounted on the air inlet end of the vortex tube 5. The hot air ends of all vortex tubes 5 are connected to a first diversion pipe 52. The main pipe of the first diversion pipe 52 is arranged around the extruder feed hopper. The first diversion pipe 52 is also connected to a first branch pipe 53. The first branch pipe 53 is equipped with a second solenoid valve 54. The first branch pipe 53 is connected to the top of the circulating water tank 44. One end of the first branch pipe 53 extending into the circulating water tank 44 is connected to a serpentine pipe 55. The serpentine pipe 55 has several exhaust holes 551 along its extension direction. The serpentine pipe 55 extends into the liquid in the circulating water tank 44. An exhaust check valve 56 is provided on the top of the circulating water tank 44.

[0043] The housing 2 is provided with a second branch pipe 21, each branch pipe section of which has its exhaust end directed towards an extruder electrical control box. The second branch pipe 21 is further connected to a second branch pipe 22, the exhaust end of which is directed towards the vacuum pump 8.

[0044] The exhaust end of the vacuum pump 8 is connected to a first gas treatment device 6, which is used to scrub and remove soluble gases from the exhaust gas and perform gas-liquid separation on the scrubbed gas. The first gas treatment device 6 includes a spray tower 61 and a gas-liquid separator 62. The exhaust end of the vacuum pump 8 is connected to the bottom air inlet of the spray tower 61. The packing layer material in the spray tower 61 is Pall rings. The spray scrubbing liquid of the spray tower 61 is an alkaline scrubbing liquid. The top exhaust end of the spray tower 61 is connected to the side air inlet of the gas-liquid separator 62. The exhaust end of the gas-liquid separator 62 is connected to a second gas treatment device 7. The discharge end of the gas-liquid separator 62 is connected to the circulating liquid tank of the spray tower 61. The second gas treatment device 7 is used to remove residual small organic molecules in the exhaust gas. The second gas treatment device 7 is an activated carbon adsorption tower 71.

[0045] like Figure 5 and Figure 6The shell 2 includes a first shell segment 23 and a second shell segment 24. Both the first shell segment 23 and the second shell segment 24 have two semicircular holes 25. The semicircular holes 25 of the first shell segment 23 correspond one to one with the semicircular holes 25 of the second shell segment 24. A plug-in plate 231 is provided on the splicing surface of the first shell segment 23 facing the second shell segment 24. The plug-in plate 231 is arranged along the circumference of the first shell segment 23 and is disconnected at the semicircular hole 25. A plug-in ring groove 241 is provided on the splicing surface of the second shell segment 24 facing the first shell segment 23. The plug-in ring groove 241 is opened along the circumference of the second shell segment 24 and is disconnected at the semicircular hole 25. A sealing gasket 242 is provided in the plug-in ring groove 241 along its circumference. The sealing gasket 242 is divided into two sections. One section of the sealing gasket 242 is located in the plug-in ring groove 241 section between the two semicircular holes 25, and the other section of the sealing gasket 242 is located in the other plug-in ring groove 241 section. When the plug-in plate 231 is inserted into the plug-in ring groove 241 and pressed against the sealing gasket 242, the first shell section 23 and the second shell section 24 are spliced together, and the corresponding semicircular holes 25 are spliced together to form a pipe opening adapted to the U-shaped connecting pipe 12. The first shell section 23 and the second shell section 24 are connected by bolts.

[0046] The implementation principle of the embodiment of the present application is as follows: under the extraction action of the vacuum pump 8, the gas discharged from the extruder passes through the vacuum tube 1, vacuum pump 8, spray tower 61, gas-liquid separator 62 and activated carbon adsorption tower 71 in sequence, and is finally discharged to the outside. When the gas enters the vacuum tube section 1 in the shell 2, the vortex tube 5 discharges cold air into the shell 2, causing the gas to condense in the vacuum tube 1, and the moisture, low molecular by-products and residual solvents in the gas at the condensation point. The gas then passes through the spray tower 61 to remove acidic gases and easily soluble small molecules in the gas, and then the gas passes through the gas-liquid separator 62 for gas-liquid separation, and then passes through the activated carbon adsorption tower 71 to adsorb VOCs in the gas and remove tail gas. At the same time, the cold air in the shell 2 can also be discharged to the electric control box and vacuum pump 8 for heat dissipation and cooling. The hot air discharged by the vortex tube 5 can be discharged to the extruder hopper, effectively preventing the oxygen absorbent raw materials from bridging, clogging and other problems due to moisture or temperature difference condensation during the feeding process. The hot air in the vortex tube 5 can also be discharged to the circulating water tank 44 to heat the water. The water in the circulating water tank 44 can be transported to the circulating flow channel 33 through the water pump 43, so as to keep the condensate warm and avoid the situation where the temperature in the shell 2 is too low and the condensate freezes and cannot be discharged smoothly.

[0047] The housing 2 plus the vortex tube 5 is used to directly perform condensation on the vacuum tube 1, which is equivalent to integrating the condensation equipment on the vacuum tube 1. That is, condensation is completed during the normal gas transportation process. The compact arrangement enables condensation and transportation to be carried out simultaneously, significantly shortening the exhaust path, reducing air resistance, and ensuring that the vacuum pump 8 can quickly establish a stable low-pressure environment at the exhaust port. The vortex tube 5 outputs cold air at temperatures below -10°C, significantly lower than the temperatures of conventional cooling water or air cooling in traditional condensing devices, resulting in enhanced instantaneous condensation capabilities. The high-temperature exhaust gas, directly exposed to the cold air within the vacuum tube 1, rapidly precipitates water vapor, low-molecular byproducts, and residual organic solvents. This ensures sufficient condensation efficiency even without increasing the length of the condensation path, mitigating the risk of gas contamination and corrosion to the vacuum pump 8 at the source. This allows the condensation process to be pre-positioned at the exhaust port of the vacuum pump 8, minimizing exhaust gas damage to the pump while maintaining condensation efficiency and ensuring stable gas extraction.

[0048] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A vacuum exhaust system for a twin-screw extruder used for processing oxygen absorbents, characterized in that: The invention comprises a vacuum tube (1) and a shell (2), wherein the vacuum tube (1) passes through the shell (2), and the air inlet end of the vacuum tube (1) is connected to the exhaust port of the extruder, the exhaust end of the vacuum tube (1) is connected to a vacuum pump (8), the exhaust end of the vacuum pump (8) is connected to a first gas treatment device (6), the first gas treatment device (6) is used to remove soluble gas in the exhaust gas, the exhaust end of the first gas treatment device (6) is connected to a second gas treatment device (7), the second gas treatment device (7) is used to remove residual organic small molecules in the exhaust gas; The shell (2) is connected to a vortex tube (5), the cold air discharge end of the vortex tube (5) is in communication with the inner cavity of the shell (2), the air inlet end of the vortex tube (5) is connected to a pressure pump (51), a liquid collecting sleeve (3) is installed in the shell (2), the liquid collecting sleeve (3) is in communication with the vacuum tube (1), and the liquid collecting sleeve (3) is used to collect condensate formed after the exhaust gas condenses in the vacuum tube (1).

2. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 1, characterized in that: The vacuum tube (1) comprises an air intake pipe (11), a U-shaped connecting pipe (12) and an exhaust pipe (13); the U-shaped connecting pipe (12) is located in the housing (2); one end of the U-shaped connecting pipe (12) is connected to the air intake pipe (11); the other end of the U-shaped connecting pipe (12) is connected to the exhaust pipe (13); a liquid discharge port (121) is provided at the bottom of the U-shaped connecting pipe (12); and the liquid collecting sleeve (3) is threadedly and sealedly connected to the liquid discharge port (121).

3. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 2, characterized in that: The U-shaped connecting pipe (12) is provided with a mounting opening (122), the mounting opening (122) being arranged opposite to the liquid discharge opening (121), a sealing cover (123) being threadedly sealed at the mounting opening (122), the sealing cover (123) being provided with a through hole (1231), an electric cylinder (14) being installed in the housing (2), one end of a push rod of the electric cylinder (14) passing through the through hole (1231) and being provided with a liquid level sensor (15), the liquid collecting sleeve (3) being connected with a liquid discharge pipe (31), the liquid discharge pipe (31) extending out of the housing (2) and being provided with a first electromagnetic valve (32), the first electromagnetic valve (32) being opened when the condensate exceeds the liquid level sensor (15), and a sealing ring (1232) being provided at the through hole (1231).

4. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 1, characterized in that: There are a plurality of vortex tubes (5), and the hot gas exhaust ends of the plurality of vortex tubes (5) are commonly connected to a first diversion pipe (52). The main pipe section of the first diversion pipe (52) is arranged around the extruder feed hopper. The shell (2) is connected to a second diversion pipe (21), and each branch pipe section of the second diversion pipe (21) corresponds one-to-one to the electric control box of the extruder.

5. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 4, characterized in that: The first branch pipe (52) is also connected to a first branch pipe (53), and the first branch pipe (53) is connected to a circulating water tank (44). A circulating flow channel (33) is provided in the side wall of the liquid collecting sleeve (3). The discharge end of the circulating water tank (44) is connected to the liquid inlet end of the circulating flow channel (33) through an inlet pipe (41), and the discharge end of the circulating flow channel (33) is connected to the liquid inlet end of the circulating water tank (44) through a drain pipe (42). The liquid in the circulating water tank (44) and the circulating flow channel (33) forms a circulating flow through a water pump (43), and the first branch pipe (53) is connected to the circulating water tank (44).

6. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 5, characterized in that: The circulating water tank (44) is provided with an exhaust check valve (56). The first branch pipe (53) is connected to a serpentine pipe (55). The serpentine pipe (55) is provided with a plurality of exhaust holes (551). The serpentine pipe (55) extends into the liquid in the circulating water tank (44). The first branch pipe (53) is provided with a second solenoid valve (54).

7. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 5, characterized in that: The outer peripheries of the liquid collecting sleeve (3), the water inlet pipe (41) and the drain pipe (42) are all provided with a heat-insulating layer (45), and the heat-insulating layer (45) is used to reduce heat exchange between the liquid collecting sleeve (3), the water inlet pipe (41) and the drain pipe (42) and the cold air in the shell (2).

8. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 4, characterized in that: The second branch pipe (21) is connected to a second branch pipe (22), and the exhaust end of the second branch pipe (22) is arranged toward the vacuum pump (8).

9. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 1, characterized in that: The first gas treatment device (6) includes a spray tower (61) and a gas-liquid separator (62), and the second gas treatment device (7) includes an activated carbon adsorption tower (71). The air inlet of the spray tower (61) is connected to the exhaust end of the vacuum pump (8), the packing layer material in the spray tower (61) is a ball ring, the spray washing liquid of the spray tower (61) adopts an alkaline washing liquid, the exhaust end of the spray tower (61) is connected to the air inlet end of the gas-liquid separator (62), the exhaust end of the gas-liquid separator (62) is connected to the air inlet end of the activated carbon adsorption tower (71), and the discharge end of the gas-liquid separator (62) is connected to the circulating liquid tank of the spray tower (61).

10. The vacuum exhaust system of a twin-screw extruder for processing oxygen absorbent according to claim 1, characterized in that: The shell (2) comprises a first shell segment (23) and a second shell segment (24), wherein the first shell segment (23) and the second shell segment (24) are both provided with a semicircular hole (25), wherein the semicircular hole (25) of the first shell segment (23) corresponds to the semicircular hole (25) of the second shell segment (24) in a one-to-one manner, and a plug-in plate (231) is provided on the splicing surface of the first shell segment (23) facing the second shell segment (24), wherein the plug-in plate (231) is provided along the circumference of the first shell segment (23), and the second shell segment (24) faces the A plug-in ring groove (241) is provided on the splicing surface of the first shell segment (23), and the plug-in ring groove (241) is opened along the circumference of the second shell segment (24). A sealing gasket (242) is provided in the plug-in ring groove (241) along its circumference. When the plug-in plate (231) is inserted into the plug-in ring groove (241) and pressed against the sealing gasket (242), the first shell segment (23) and the second shell segment (24) are spliced, and the corresponding semicircular holes (25) are spliced to form a pipe mouth adapted to the vacuum tube (1).

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