A paper drying ventilation system

Abstract

This invention discloses a paper drying ventilation system. A high-temperature hot air delivery mechanism precisely blows hot air into the bag area formed between the drying cylinder and the drying wire, effectively expelling moisture from the bag area and preventing heat transfer obstruction during paper drying, thus improving drying efficiency. Furthermore, a ventilation airbag serves as the connecting carrier for the jet nozzles. Upon injection of hot air, the airbag elastically expands, and its inner wall experiences uniform force, resulting in consistent static pressure within the cavity. This significantly reduces the pressure difference between the front and rear ends of traditional ventilation pipes, allowing each jet nozzle to operate under similar pressure and achieve uniform hot air injection. The ventilation airbag is composed of a rubber inner layer and a woven outer layer, providing excellent pressure resistance, flexibility, and fatigue resistance. Simultaneously, the exhaust mechanism uses a centrifugal fan to draw high-humidity air from the top of the hot air hood, preventing moisture condensation and dripping that could affect paper quality or corrode equipment. The filter assembly intercepts impurities such as paper fibers and lint.

Description

Technical Field

[0001] This invention relates to the field of papermaking equipment technology, and in particular to a paper drying and ventilation system. Background Technology

[0002] In the papermaking process, the drying process is one of the core steps to ensure paper quality and improve production efficiency. The ventilation system and condensate treatment method of the drying department directly determine the drying efficiency, energy consumption and production stability.

[0003] Currently, the paper industry mostly uses a drying mode combining a hot air hood and a drying cylinder. However, the ventilation design of the traditional paper machine drying section has significant flaws: moisture in the hot air hood (mainly the bag area formed between the drying cylinder and the wire) is difficult to expel effectively, resulting in obstructed heat transfer during paper web drying and low drying efficiency. Especially in winter, the high temperature and humidity environment inside the hot air hood easily produces condensation dripping, which not only wets the paper web and affects product quality but also interferes with the production process and may even cause equipment failure. Therefore, there is an urgent need to select a better drying and ventilation system to solve this technical problem. Summary of the Invention

[0004] The purpose of this invention is to provide a paper drying ventilation system that reduces moisture inside the hot air hood.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a paper drying ventilation system, including a frame, a hot air hood set on the frame and used to cover the drying section of a paper machine, and a ventilation device for discharging moisture from the hot air hood. The hot air hood is provided with electric lifting doors at both ends and multiple sliding doors on both sides of the hot air hood. The electric lifting doors and sliding doors are each provided with an observation window. The ventilation device includes multiple air supply mechanisms set on the hot air hood for conveying drying hot air to the bag area formed between the drying cylinder and the drying wire, an air heating and conveying mechanism for inputting hot air into the multiple air supply mechanisms, and multiple exhaust mechanisms set on the top of the hot air hood for extracting high-humidity air from the hot air hood. The air supply mechanism includes a ventilation duct disposed inside a hot air hood and a ventilation airbag disposed inside the ventilation duct. The ventilation duct has multiple ventilation hole groups arranged along its length on its periphery. Each ventilation hole group includes multiple ventilation holes distributed in a circumferential array. The ventilation airbag is provided with multiple jet nozzles extending out of the ventilation holes. One end of the ventilation airbag is provided with a connecting component installed at the end of the ventilation duct. The air heating and delivery mechanism delivers high-speed hot air into the ventilation airbag. The ventilation airbag is composed of a rubber inner layer and a woven outer layer. The top of the hot air hood is provided with multiple exhaust ports. The exhaust mechanism includes a filter assembly installed at the exhaust port, a centrifugal fan installed on the top of the hot air hood and connected to the exhaust port, and an exhaust duct connected to the air outlet of the multiple centrifugal fans.

[0006] By adopting the above technical solution, high-temperature hot air is precisely blown into the bag area formed between the drying cylinder and the drying wire through the air supply mechanism, so that the moisture in the bag area can be effectively discharged, avoiding the obstruction of heat transfer during paper drying and improving drying efficiency. Moreover, the ventilation airbag is used as the connecting carrier of the jet nozzle. After the hot air is injected, the ventilation airbag expands elastically, and the inner wall is evenly stressed, so that the static pressure in the cavity tends to be uniform. This significantly reduces the air pressure difference between the front and the end of the traditional ventilation pipe, so that each jet nozzle works under similar pressure and achieves uniform jetting of hot air. The ventilation airbag is composed of a rubber inner layer and a woven outer layer, which has good pressure resistance, flexibility and fatigue resistance. At the same time, the exhaust mechanism uses a centrifugal fan to draw high-humidity air from the top of the hot air hood, preventing moisture condensation and dripping that may affect paper quality or corrode equipment. The filter component can intercept paper lint, fibers and other impurities, protecting the fan and pipeline system and extending the service life of the equipment.

[0007] A further feature of the present invention is that the size of the ventilation hole is larger than the maximum outer diameter of the jet connector, so as to ensure that the jet connector protrudes through the ventilation hole during the inflation of the ventilation airbag; The ventilation airbag is provided with a plurality of metal plug-in profiles arranged in a circular array and extending along its length. Each jet connector is located between two metal plug-in profiles. The ventilation pipe is provided with a plurality of plug-in parts for the metal plug-in profiles to be plugged in. The vent pipe is provided with an annular groove at the ventilation hole group that communicates with multiple ventilation holes. The annular groove of the vent pipe is provided with an elastic support mechanism to assist in supporting multiple jet nozzles to prevent shaking. During the inflation of the ventilation airbag, the jet nozzles drive the elastic support mechanism to open and achieve fixation. During the process of the ventilation airbag being pulled out of the vent pipe, the nozzle nozzles drive the elastic support mechanism to open and release the fixation.

[0008] By adopting the above technical solution, firstly, the ventilation airbag is provided with a circumferential array of metal plug-in profiles to facilitate the insertion of the ventilation airbag into the plug-in part of the ventilation pipe for installation. The metal plug-in profiles also support the ventilation airbag, preventing it from twisting and ensuring that the jet nozzle is aligned with the ventilation hole. Simultaneously, during the inflation of the ventilation airbag, the size of the ventilation hole is larger than the maximum outer diameter of the jet nozzle, ensuring that the jet nozzle protrudes through the ventilation hole during inflation. An elastic support mechanism further supports the jet nozzle to prevent wobbling. Furthermore, when the ventilation airbag needs to be disassembled, it can be pulled out directly, and the nozzle connector opens the elastic support mechanism to release the fixation.

[0009] A further feature of the present invention is that: an annular groove is provided on the periphery of the jet connector, a first guide slope is provided on the jet connector that contacts the elastic support mechanism during the extension of the ventilation hole, and a second guide slope is provided on the edge of the annular groove away from the ventilation airbag. The elastic support mechanism includes multiple arc-shaped buckles symmetrically arranged on the ventilation duct and located on both sides of the arc-shaped groove, and multiple elastic components arranged between the ventilation duct and the arc-shaped buckles. Two arc-shaped buckles corresponding to the same jet connector move toward each other under the action of the elastic components. During the inflation of the ventilation airbag, the first guide slope acts on the two arc-shaped fasteners, overcoming the elastic force of the elastic component and causing the two arc-shaped fasteners to move away from each other. When the arc-shaped fasteners move to the position of the annular groove, they are embedded in the annular groove and fixed under the action of the elastic component. During the de-inflation of the ventilation airbag, the second guide slope acts on the two arc-shaped fasteners, overcoming the elastic force of the elastic component and causing the two arc-shaped fasteners to move away from each other, so that the elastic support mechanism releases its auxiliary support for the jet nozzle.

[0010] By adopting the above technical solution, during the inflation of the ventilation airbag, the first guide slope acts on the two arc-shaped buckles, and after overcoming the elastic force of the elastic component, the two arc-shaped buckles move away from each other. When the arc-shaped buckles move to the position of the annular groove, the arc-shaped buckles are embedded in the annular groove for fixation under the action of the elastic component. During the withdrawal of the ventilation airbag, the second guide slope acts on the two arc-shaped buckles, and after overcoming the elastic force of the elastic component, the two arc-shaped buckles move away from each other, so that the elastic support mechanism releases the auxiliary support for the jet connector.

[0011] A further embodiment of the present invention is that the elastic component includes a limiting seat disposed on an annular groove, a guide shaft disposed on an arc-shaped buckle plate and passing through the limiting seat, an anti-loosening nut disposed at one end of the guide shaft passing through the limiting seat, and a compression spring sleeved on the guide shaft and with both ends abutting between the limiting seat and the arc-shaped buckle plate.

[0012] By adopting the above technical solution, the compression spring can drive the two arc-shaped buckles to move toward the jet nozzle, and the anti-loosening nut can adjust the maximum stroke of the jet nozzle toward the nozzle connector.

[0013] A further configuration of the present invention is as follows: one end of the ventilation duct extends outside the hot air hood, the opening of the ventilation duct is provided with an annular stepped groove, the connecting assembly includes an annular ring fixedly disposed at the end of the ventilation airbag and embedded in the annular stepped groove, a rubber sealing ring disposed on the front and rear end faces of the annular ring, and a ventilation hood detachably connected to the end face of the ventilation duct and pressing the annular ring; the air heating and conveying mechanism is connected to the ventilation hood.

[0014] By adopting the above technical solution, the ventilation hood is detachable to facilitate the inspection and replacement of the ventilation airbag; at the same time, the rubber sealing ring of the connecting components can ensure the sealing of the ventilation duct end, the ventilation airbag end, and the connection of the ventilation hood.

[0015] A further configuration of the present invention is as follows: the air heating and conveying mechanism includes an air heater, a main pipe disposed at the output end of the air heater, multiple branch pipes, multiple exhaust fans connected between the main pipe and the branch pipes, and a corrugated pipe disposed between the branch pipes and the ventilation hood.

[0016] By adopting the above technical solution, when disassembling the ventilation cover to inspect and replace the ventilation airbag, the connection between the ventilation cover and the air heating and conveying mechanism does not need to be disassembled due to the setting of the bellows.

[0017] A further configuration of the present invention is as follows: a first flange is provided at one end of the ventilation duct extending outside the hot air hood, and a second flange is provided on the ventilation hood; the first flange and the second flange are connected by a plurality of bolts and nuts; when the ventilation hood is in a fixed state, the bellows extends in a horizontal direction. A support assembly is provided between the ventilation hood and the branch pipe to prevent the ventilation hood from falling directly after the bolts and nuts connecting the ventilation hood are removed; the support assembly includes a rotating bracket rotatably connected to the branch pipe at both ends and in the shape of a U, an insert seat set on the ventilation hood and for the rotating bracket to be inserted in the middle, a fixing bolt set between the insert seat and the rotating bracket, and a limiting block set on both sides of the branch pipe to limit the downward rotation angle of the rotating bracket. After the bolts and nuts connecting the ventilation hood are removed, the rotating bracket rotates downward to the position where it touches the limiting block. The end of the ventilation hood and the ventilation duct do not overlap, and the corrugated pipe is in an arc-shaped bending state.

[0018] By adopting the above technical solution, after the bolts and nuts connecting the ventilation hood are removed, the rotating bracket is rotated downwards to the position of touching the limit block. The ends of the ventilation hood and the ventilation duct do not overlap, and the corrugated pipe is in an arc-shaped bending state. This achieves support for the disassembled ventilation hood, avoids affecting the disassembly and assembly of the ventilation airbag, and also avoids the ventilation hood pulling on the corrugated pipe, which would cause irreversible deformation of the corrugated pipe.

[0019] A further provision of the present invention is that the filter assembly includes a frame detachably disposed inside the hot air hood and covering the exhaust port, a metal filter screen disposed inside the frame, and an impurity recovery device disposed inside the hot air hood for cleaning and collecting impurities on the metal filter screen.

[0020] By adopting the above technical solution, the metal filter screen of the filter assembly can filter impurities such as paper lint and fibers. However, impurities will affect the exhaust efficiency of the filter assembly. Therefore, by setting up an impurity recovery device, the impurities on the metal filter screen can be cleaned and collected to ensure the exhaust efficiency.

[0021] A further embodiment of the present invention is as follows: the impurity recovery device includes a collection box slidably disposed within a hot air hood, a belt conveyor mechanism disposed between the hot air hood and the collection box and driving the collection box to rotate back and forth, a plurality of brush rollers rotatably connected to the top of the collection box, a linkage structure disposed between the brush rollers and the hot air hood and driving the brush rollers to rotate when the brush rollers move to the metal filter screen, a recovery box disposed at one end of the hot air hood, and a negative pressure dust collector communicating with the bottom of the recovery box. The top of the recovery box is provided with a receiving pipe, and the bottom of the collection box is provided with a recovery pipe that is inserted into the receiving pipe during movement.

[0022] By adopting the above technical solution, the belt conveyor mechanism can drive the collection box to reciprocate. After the brush roller of the collection box moves back and forth at the metal filter screen, the linkage structure can drive the brush roller to rotate, thereby brushing away the impurities on the metal filter screen. The brushed impurities can fall into the collection box for collection. Finally, after the recovery pipe on the collection box moves and is inserted into the recovery box, the impurities are sucked away and recovered by the negative pressure dust collector.

[0023] A further configuration of the present invention is as follows: the linkage structure includes a plurality of gears disposed at the end of the brush roller and a plurality of racks disposed at the top of the hot air hood. When the brush roller moves to the range of the metal filter screen, the gears and racks mesh to drive the brush roller to rotate.

[0024] By adopting the above technical solution, when the brush roller moves to the range of the metal filter screen, the gear and rack mesh to drive the brush roller to rotate, so as to achieve rolling cleaning of impurities on the metal filter screen.

[0025] The beneficial effects of this invention are as follows: The air supply mechanism precisely blows high-temperature hot air into the bag area formed between the drying cylinder and the drying wire, effectively expelling moisture from the bag area and preventing heat transfer obstruction during paper drying, thus improving drying efficiency. Furthermore, the ventilation airbag, acting as a connecting carrier for the jet nozzles, expands elastically after hot air injection, resulting in uniform stress on its inner wall and consistent static pressure within the cavity. This significantly reduces the pressure difference between the front and rear ends of traditional ventilation pipes, allowing each jet nozzle to operate under similar pressure, achieving uniform hot air jetting. The ventilation airbag, composed of a rubber inner layer and a woven outer layer, possesses excellent pressure resistance, flexibility, and fatigue resistance. Simultaneously, the exhaust mechanism uses a centrifugal fan to draw high-humidity air from the top of the hot air hood, preventing moisture condensation and dripping that could affect paper quality or corrode equipment. The filter assembly intercepts paper fibers and other impurities, protecting the fan and piping system and extending equipment lifespan. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a partial structural schematic diagram of the present invention; Figure 3 This is a schematic diagram of the air supply mechanism and part of the air heating and conveying mechanism in this invention; Figure 4 This is a partial exploded view of the air supply mechanism in this invention; Figure 5 This is a partial exploded view of the air supply mechanism and the air heating and conveying mechanism in this invention; Figure 6 yes Figure 5 A magnified view of the area located at point A; Figure 7 This is a cross-sectional view of the structure located at the air supply mechanism in this invention; Figure 8 This is a schematic diagram of the structure of part of the air supply mechanism and part of the air heating and conveying mechanism in this invention; Figure 9 This is a partial structural cross-sectional view located on the right side of the present invention; Figure 10 yes Figure 9 A magnified view of the area located at point B.

[0027] In the diagram: 1. Frame; 2. Hot air hood; 21. Exhaust port; 3. Ventilation device; 31. Air supply mechanism; 311. Ventilation pipe; 3111. Ventilation hole group; 3112. Insertion part; 3113. Annular groove; 3114. Annular stepped groove; 3115. First flange; 312. Ventilation airbag; 3121. Jet connector; 31211. Annular slot; 31212. First guide slope; 31213. Second guide slope; 3122. Metal insertion profile; 313. Connecting assembly; 3131. Annular ring; 3132. Rubber sealing ring; 3133. Ventilation hood; 31331. Second flange; 314. Elastic support mechanism; 3141. Arc-shaped buckle plate; 3142. Elastic component; 31421. Limit seat; 31422. Guide shaft; 31423 1. Anti-loosening nut; 31424. Compression spring; 32. Air heating and conveying mechanism; 321. Air heater; 322. Main pipe; 323. Branch pipe; 324. Exhaust fan; 325. Corrugated pipe; 33. Exhaust mechanism; 331. Filter assembly; 3311. Frame; 3312. Metal filter screen; 332. Centrifugal fan; 333. Exhaust duct; 34. Support assembly; 341. Rotating bracket; 342. Embedded seat; 343. Fixing bolt; 344. Limit block; 4. Electric lifting door; 5. Sliding door; 6. Impurity recovery device; 61. Collection box; 611. Recovery pipe; 62. Belt transmission mechanism; 621. Gear; 622. Rack; 63. Brush roller; 64. Linkage structure; 65. Recovery box; 651. Receiving pipe; 66. Negative pressure dust collector. Detailed Implementation

[0028] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Example: A paper drying ventilation system, such as Figure 1 As shown, it includes a frame 1, a hot air hood 2 mounted on the frame 1 and used to cover the drying section of the paper machine, and a ventilation device for discharging moisture from the hot air hood 2. Electric lifting doors 4 are provided at both ends of the hot air hood 2, and multiple sliding doors 5 are provided on both sides of the hot air hood 2. Observation windows are provided on both the electric lifting doors 4 and the sliding doors 5.

[0030] like Figure 1As shown, the ventilation device includes multiple air supply mechanisms 31 installed on the hot air hood 2 to deliver dry hot air to the bag area formed between the drying cylinder and the drying net, an air heating and conveying mechanism 32 for inputting hot air into the multiple air supply mechanisms 31, and multiple exhaust mechanisms 33 installed on the top of the hot air hood 2 to extract the high humidity air inside the hot air hood 2.

[0031] like Figures 1 to 4 As shown, the air supply mechanism 31 includes a ventilation pipe 311 disposed within the hot air hood 2 and a ventilation airbag 312 disposed within the ventilation pipe 311. Multiple ventilation hole groups 3111 are arranged along the length of the ventilation pipe 311, each ventilation hole group 3111 including multiple ventilation holes distributed in a circumferential array. Multiple jet nozzles 3121 extending from the ventilation holes are disposed on the ventilation airbag 312. A connecting component 313 installed at the end of the ventilation pipe 311 is disposed at one end of the ventilation airbag 312. An air heating and delivery mechanism 32 delivers high-speed hot air into the ventilation airbag 312. The ventilation airbag 312 is composed of a rubber inner layer and a woven outer layer. Furthermore, in this application, the inner diameter of the ventilation airbag 312 is not less than 800 mm, allowing an adult male to crawl through it.

[0032] like Figures 2 to 5 As shown, the size of the ventilation hole is larger than the maximum outer diameter of the jet connector 3121 to ensure that the jet connector 3121 can pass through the ventilation hole during the inflation of the ventilation airbag 312. Multiple metal plug-in profiles 3122 are arranged in a circumferential array and extend along the length of the ventilation airbag 312. Each jet connector 3121 is located between two metal plug-in profiles 3122. Multiple plug-in portions 3112 for inserting the metal plug-in profiles 3122 are provided inside the ventilation pipe 311. The vent pipe is provided with an annular groove 3113 at the ventilation hole group 3111, which communicates with multiple ventilation holes. The annular groove 3113 of the vent pipe is provided with an elastic support mechanism 314 to assist in supporting multiple jet connectors 3121 to prevent shaking. During the inflation of the ventilation airbag 312, the jet connectors 3121 drive the elastic support mechanism 314 to open and fix it. During the process of the ventilation airbag 312 being pulled out of the vent pipe, the nozzle connectors drive the elastic support mechanism 314 to open and release the fixation.

[0033] like Figures 4 to 7As shown, an annular groove 31211 is provided around the jet connector 3121. A first guide slope 31212 is provided on the jet connector 3121 during the process of extending the ventilation hole and contacting the elastic support mechanism 314. A second guide slope 31213 is provided on the edge of the annular groove 31211 away from the ventilation airbag 312. The elastic support mechanism 314 includes multiple arc-shaped buckles 3141 symmetrically arranged on the ventilation pipe 311 and located on both sides of the arc-shaped groove, and multiple elastic components 3142 disposed between the ventilation pipe 311 and the arc-shaped buckles 3141. Two arc-shaped buckles 3141 corresponding to the same jet connector 3121 move towards each other under the action of the elastic components 3142. The elastic component 3142 includes a limiting seat 31421 disposed on the annular groove 3113, a guide shaft 31422 (with threads at the end) disposed on the arc-shaped buckle plate 3141 and passing through the limiting seat 31421, an anti-loosening nut 31423 threadedly connected to one end of the guide shaft 31422 passing through the limiting seat 31421, and a compression spring 31424 sleeved on the guide shaft 31422 and with both ends pressed against the limiting seat 31421 and the arc-shaped buckle plate 3141. During the inflation of the ventilation airbag 312, the first guide slope 31212 acts on the two arc-shaped fasteners 3141. After overcoming the elastic force of the elastic component 3142, the two arc-shaped fasteners 3141 move away from each other. When the arc-shaped fasteners 3141 move to the position of the annular groove 31211, they are embedded in the annular groove 31211 and fixed under the action of the elastic component 3142. During the withdrawal of the ventilation airbag 312, the second guide slope 31213 acts on the two arc-shaped fasteners 3141. After overcoming the elastic force of the elastic component 3142, the two arc-shaped fasteners 3141 move away from each other, so that the elastic support mechanism 314 releases its auxiliary support to the jet connector 3121.

[0034] like Figure 3 and Figure 4 As shown, one end of the ventilation duct 311 extends outside the hot air hood 2. An annular stepped groove 3114 is provided at the opening of the ventilation duct 311. The connecting assembly 313 includes an annular ring 3131 fixedly disposed at the end of the ventilation airbag 312 and embedded in the annular stepped groove 3114, a rubber sealing ring 3132 disposed on the front and rear end faces of the annular ring 3131, and a ventilation hood 3133 detachably connected to the end face of the ventilation duct 311 and pressing the annular ring 3131.

[0035] like Figures 1 to 5As shown, the air heating and conveying mechanism 32 is connected to the ventilation hood 3133. The air heating and conveying mechanism 32 includes an air heater 321, a main pipe 322 disposed at the output end of the air heater 321, multiple branch pipes 323 disposed at the main pipe 322, multiple exhaust fans 324 connected between the main pipe 322 and the branch pipes 323, and a corrugated pipe 325 disposed between the branch pipes 323 and the ventilation hood 3133.

[0036] like Figure 5 and Figure 8 As shown, a first flange 3115 is provided at one end of the ventilation duct 311 extending outside the hot air hood 2, and a second flange 31331 is provided on the ventilation hood 3133. The first flange 3115 and the second flange 31331 are connected by multiple bolts and nuts. When the ventilation hood 3133 is in a fixed state, the bellows 325 extends horizontally. A support assembly 34 is provided between the ventilation hood 3133 and the branch pipe 323 to prevent the ventilation hood 3133 from falling directly after the bolts and nuts connecting the ventilation hood 3133 are removed. The support assembly 34 includes a rotating bracket 341 rotatably connected to the branch pipe 323 at both ends and in a U-shape, an insert seat 342 provided on the ventilation hood 3133 and for the rotating bracket 341 to be inserted into the middle, a fixing bolt 343 provided between the insert seat 342 and the rotating bracket 341, and a limiting block 344 provided on both sides of the branch pipe 323 to limit the downward rotation angle of the rotating bracket 341. After the bolts and nuts connecting the ventilation hood 3133 are removed, the rotating bracket 341 rotates downward to the position of touching the limit block 344. The end of the ventilation hood 3133 and the ventilation pipe 311 do not overlap, and the corrugated pipe 325 is in an arc-shaped bending state.

[0037] like Figure 1 , Figure 9 and Figure 10 As shown, the top of the hot air hood 2 is provided with multiple exhaust ports 21. The exhaust mechanism 33 includes a filter assembly 331 disposed at the exhaust port 21, a centrifugal fan 332 installed on the top of the hot air hood 2 and communicating with the exhaust port 21, and an exhaust duct 333 communicating with the air outlets of the multiple centrifugal fans 332. The filter assembly 331 includes a frame 3311 detachably disposed inside the hot air hood 2 and covering the exhaust port 21, and a metal filter screen 3312 disposed inside the frame 3311 (the metal filter screen 3312 protrudes entirely from the lower surface of the frame 3311). An impurity recovery device 6 is provided inside the hot air hood 2 to clean and collect impurities on the metal filter screen 3312.

[0038] like Figure 1 , Figure 9 and Figure 10As shown, the impurity recovery device 6 includes a collection box 61 slidably disposed inside the hot air hood 2, a belt transmission mechanism 62 disposed between the hot air hood 2 and the collection box 61 and driving the collection box 61 to rotate back and forth (composed of a transmission belt and a servo motor, with the collection box and the upper side of the transmission belt fixed, which is an existing transmission technology), multiple brush rollers 63 rotatably connected to the top of the collection box 61, a linkage structure 64 disposed between the brush rollers 63 and the hot air hood 2 and driving the brush rollers 63 to rotate when the brush rollers 63 move to the metal filter screen 3312, a recovery box 65 disposed at one end of the hot air hood 2, and a negative pressure dust collector 66 communicating with the bottom of the recovery box 65. The top of the recovery box 65 is provided with a receiving pipe 651, and the bottom of the collection box 61 is provided with a recovery pipe 611 that is inserted into the receiving pipe 651 during movement. The linkage structure 64 includes multiple gears 621 disposed at the ends of the brush roller 63 and multiple racks 622 disposed at the top of the hot air hood 2. When the brush roller 63 moves into the range of the metal filter screen 3312, the gears 621 and racks 622 mesh to drive the brush roller 63 to rotate. The end of the recovery pipe 611 extends upward at an angle to prevent impurities from falling directly out from the end of the recovery pipe.

[0039] Implementation Results: The air supply mechanism 31 precisely blows high-temperature hot air into the bag area formed between the drying cylinder and the drying wire, allowing moisture in the bag area to be effectively discharged, avoiding obstruction of heat transfer during paper drying and improving drying efficiency. Furthermore, the ventilation airbag 312 serves as the connecting carrier for the jet nozzles 3121. After hot air is injected, the ventilation airbag 312 elastically expands, and the inner wall is evenly stressed, making the static pressure within the cavity more uniform. This significantly reduces the pressure difference between the front and rear ends of the traditional ventilation pipe 311, allowing each jet nozzle 3121 to operate under similar pressure, achieving uniform hot air jetting. The ventilation airbag 312 is composed of a rubber inner layer and a woven outer layer, possessing good pressure resistance, flexibility, and fatigue resistance. Simultaneously, the exhaust mechanism 33 uses a centrifugal fan 332 to extract high-humidity air from the top of the hot air hood 2, preventing moisture condensation and dripping that could affect paper quality or corrode equipment. The filter component 331 can intercept paper fibers and other impurities, protecting the fan and piping system and extending equipment life.

[0040] Firstly, the ventilation airbag 312 is provided with a circumferential array of metal insertion profiles 3122 to facilitate the insertion of the ventilation airbag 312 into the insertion part 3112 of the ventilation pipe 311 for installation. The metal insertion profiles 3122 also support the ventilation airbag 312 to prevent it from twisting and allow the jet nozzle 3121 to be aligned with the ventilation hole. During the inflation of the ventilation airbag 312, the size of the ventilation hole is larger than the maximum outer diameter of the jet nozzle 3121 to ensure that the jet nozzle 3121 can pass through the ventilation hole during the inflation of the ventilation airbag 312. The jet nozzle 3121 is further supported by the elastic support mechanism 314 to prevent shaking. In addition, when the ventilation airbag 312 needs to be disassembled, it can be pulled out directly, and the nozzle connector drives the elastic support mechanism 314 to open and release the fixation.

[0041] During the inflation of the ventilation airbag 312, the first guide slope 31212 acts on the two arc-shaped fasteners 3141. After overcoming the elastic force of the elastic component 3142, the two arc-shaped fasteners 3141 move away from each other. When the arc-shaped fasteners 3141 move to the position of the annular groove 31211, they are embedded in the annular groove 31211 and fixed under the action of the elastic component 3142. During the withdrawal of the ventilation airbag 312, the second guide slope 31213 acts on the two arc-shaped fasteners 3141. After overcoming the elastic force of the elastic component 3142, the two arc-shaped fasteners 3141 move away from each other, so that the elastic support mechanism 314 releases its auxiliary support to the jet connector 3121. The compression spring 31424 can drive the two arc-shaped buckles 3141 to move toward the jet nozzle 3121, and the anti-loosening nut 31423 can adjust the maximum stroke of the jet nozzle 3121 toward the nozzle connector.

[0042] The detachable design of the ventilation hood 3133 facilitates the inspection and replacement of the ventilation airbag 312. Simultaneously, the rubber sealing ring 3132 of the connecting component 313 ensures the sealing of the connection between the end of the ventilation pipe 311, the end of the ventilation airbag 312, and the ventilation hood 3133. When disassembling the ventilation hood 3133 to inspect and replace the ventilation airbag 312, the corrugated pipe 325 prevents disassembly at the connection between the ventilation hood 3133 and the air heating and conveying mechanism 32. After the bolts and nuts connecting the ventilation hood 3133 are removed, the rotating bracket 341 rotates downwards to the position where it touches the limiting block 344. The end of the ventilation hood 3133 and the ventilation pipe 311 do not overlap, and the corrugated pipe 325 is in an arc-shaped bent state. This supports the disassembled ventilation hood 3133, avoids affecting the disassembly and assembly of the ventilation airbag, and prevents the ventilation hood 3133 from pulling on the corrugated pipe 325, which could lead to irreversible deformation of the corrugated pipe 325.

[0043] The metal filter screen 3312 of the filter assembly 331 can filter impurities such as paper lint and fibers. However, these impurities can affect the exhaust efficiency of the filter assembly 331. Therefore, an impurity recovery device 6 is installed to clean and collect the impurities on the metal filter screen 3312 to ensure exhaust efficiency. The belt conveyor mechanism 62 can drive the collection box 61 to reciprocate. After the brush roller 63 of the collection box 61 moves back and forth over the metal filter screen 3312, the linkage structure 64 can drive the brush roller 63 to rotate, thereby brushing away the impurities on the metal filter screen 3312. The brushed impurities can fall into the collection box 61 for collection. Finally, after the recovery pipe 611 on the collection box 61 moves and is inserted into the recovery box 65, the impurities are sucked back by the negative pressure dust collector 66. When the brush roller 63 moves into the range of the metal filter screen 3312, the gear 621 meshes with the rack 622 to drive the brush roller 63 to rotate, thereby cleaning the impurities on the metal filter screen 3312 by rolling.

Claims

1. A paper drying ventilation system comprising a frame (1), a hot air hood (2) arranged on the frame (1) and used to cover a drying section of a paper machine, a ventilation device for discharging moisture in the hot air hood (2), electrically operated lifting doors (4) arranged at both ends of the hot air hood (2), and a plurality of sliding doors (5) arranged at both sides of the hot air hood (2), wherein the electrically operated lifting doors (4) and the sliding doors (5) are each provided with an observation window. The ventilation device includes multiple air supply mechanisms (31) installed on the hot air hood (2) to deliver dry hot air to the bag area formed between the drying cylinder and the drying net, an air heating and conveying mechanism (32) for inputting hot air to the multiple air supply mechanisms (31), and multiple exhaust mechanisms (33) installed on the top of the hot air hood (2) to extract the high humidity air inside the hot air hood (2). The air supply mechanism (31) includes a ventilation pipe (311) disposed in the hot air hood (2) and a ventilation airbag (312) disposed in the ventilation pipe (311). The ventilation pipe (311) has a plurality of ventilation hole groups (3111) arranged along its length direction on its periphery. Each ventilation hole group (3111) includes a plurality of ventilation holes distributed in a circular array. The ventilation airbag (312) is provided with a plurality of jet nozzles (3121) extending out of the ventilation holes. One end of the ventilation airbag (312) is provided with a connecting component (313) installed at the end of the ventilation pipe (311). The air heating and conveying mechanism (32) delivers high-speed hot air into the ventilation airbag (312). The ventilation airbag (312) is composed of a rubber inner layer and a woven outer layer. The top of the hot air hood (2) is provided with multiple exhaust ports (21), and the exhaust mechanism (33) includes a filter assembly (331) provided at the exhaust port (21), a centrifugal fan (332) installed on the top of the hot air hood (2) and connected to the exhaust port (21), and an exhaust duct (333) connected to the air outlet of the multiple centrifugal fans (332).

2. The paper drying and ventilation system according to claim 1, characterized in that: The size of the ventilation hole is larger than the maximum outer diameter of the jet connector (3121) to ensure that the jet connector (3121) protrudes through the ventilation hole during the inflation of the ventilation airbag (312); The ventilation airbag (312) is provided with a plurality of metal plug-in profiles (3122) arranged in a circular array and extending along its length. Each jet connector (3121) is located between two metal plug-in profiles (3122). The ventilation pipe (311) is provided with a plurality of plug-in parts (3112) for the metal plug-in profiles (3122) to be plugged into. The vent pipe is provided with an annular groove (3113) at the ventilation hole group (3111) that communicates with multiple ventilation holes. The annular groove (3113) of the vent pipe is provided with an elastic support mechanism (314) to provide auxiliary support for multiple jet nozzles (3121) to prevent shaking. During the inflation of the ventilation airbag (312), the jet nozzle (3121) drives the elastic support mechanism (314) to open and achieve fixation. During the process of the ventilation airbag (312) being pulled out from the vent pipe, the nozzle nozzle drives the elastic support mechanism (314) to open and release the fixation.

3. The paper drying and ventilation system according to claim 2, characterized in that: The jet connector (3121) is provided with an annular groove (31211) on its periphery. The jet connector (3121) is provided with a first guide slope (31212) that contacts the elastic support mechanism (314) during the extension of the ventilation hole. The annular groove (31211) is provided with a second guide slope (31213) on the edge away from the ventilation airbag (312). The elastic support mechanism (314) includes multiple arc-shaped buckles (3141) symmetrically arranged on the ventilation pipe (311) and located on both sides of the arc groove, and multiple elastic components (3142) arranged between the ventilation pipe (311) and the arc-shaped buckles (3141). Two arc-shaped buckles (3141) corresponding to the same jet connector (3121) move towards each other under the action of the elastic components (3142). During the inflation of the ventilation airbag (312), the first guide slope (31212) acts on the two arc-shaped buckles (3141), and after overcoming the elastic force of the elastic component (3142), the two arc-shaped buckles (3141) move away from each other. When the arc-shaped buckles (3141) move to the position of the annular groove (31211), the arc-shaped buckles (3141) are embedded in the annular groove (31211) and fixed under the action of the elastic component (3142). During the withdrawal of the ventilation airbag (312), the second guide slope (31213) acts on the two arc-shaped buckles (3141), and after overcoming the elastic force of the elastic component (3142), the two arc-shaped buckles (3141) move away from each other, so that the elastic support mechanism (314) releases the auxiliary support of the jet connector (3121).

4. The paper drying and ventilation system according to claim 3, characterized in that: The elastic component (3142) includes a limiting seat (31421) disposed on an annular groove (3113), a guide shaft (31422) disposed on an arc-shaped buckle plate (3141) and passing through the limiting seat (31421), an anti-loosening nut (31423) disposed on one end of the guide shaft (31422) passing through the limiting seat (31421), and a compression spring (31424) sleeved on the guide shaft (31422) and with both ends pressed against the limiting seat (31421) and the arc-shaped buckle plate (3141).

5. A paper drying and ventilation system according to claim 1, characterized in that: One end of the ventilation duct (311) extends outside the hot air hood (2), and an annular stepped groove (3114) is provided at the opening of the ventilation duct (311). The connecting assembly (313) includes an annular ring (3131) fixedly disposed at the end of the ventilation airbag (312) and embedded in the annular stepped groove (3114), a rubber sealing ring (3132) disposed on the front and rear end faces of the annular ring (3131), and a ventilation hood (3133) detachably connected to the end face of the ventilation duct (311) and pressing the annular ring (3131). The air heating and conveying mechanism (32) is connected to the ventilation hood (3133).

6. A paper drying and ventilation system according to claim 5, characterized in that: The air heating and conveying mechanism (32) includes an air heater (321), a main pipe (322) disposed at the output end of the air heater (321), multiple branch pipes (323) disposed on the main pipe (322), multiple exhaust fans (324) connected between the main pipe (322) and the branch pipes (323), and a corrugated pipe (325) disposed between the branch pipes (323) and the ventilation hood (3133).

7. A paper drying and ventilation system according to claim 6, characterized in that: The ventilation duct (311) extends to the outside of the hot air hood (2) and is provided with a first flange (3115). The ventilation hood (3133) is provided with a second flange (31331). The first flange (3115) and the second flange (31331) are connected by a plurality of bolts and nuts. When the ventilation hood (3133) is in a fixed state, the corrugated pipe (325) extends in the horizontal direction. A support assembly (34) is provided between the ventilation hood (3133) and the branch pipe (323) to prevent the ventilation hood (3133) from falling directly after the bolts and nuts connecting the ventilation hood (3133) are removed; the support assembly (34) includes a rotating bracket (341) rotatably connected to the branch pipe (323) at both ends and in the shape of a U, an insert seat (342) provided on the ventilation hood (3133) and for the rotating bracket (341) to be inserted into the middle, a fixing bolt (343) provided between the insert seat (342) and the rotating bracket (341), and a limiting block (344) provided on both sides of the branch pipe (323) and limiting the downward rotation angle of the rotating bracket (341). After the bolts and nuts connecting the ventilation hood (3133) are removed, the rotating bracket (341) rotates downward to the position of touching the limiting block (344), the ventilation hood (3133) and the end of the ventilation pipe (311) do not overlap, and the corrugated pipe (325) is in an arc-shaped bending state.

8. A paper drying and ventilation system according to claim 1, characterized in that: The filter assembly (331) includes a frame (3311) that is detachably disposed inside the hot air hood (2) and covers the exhaust port (21), and a metal filter screen (3312) disposed inside the frame (3311). The hot air hood (2) is provided with an impurity recovery device (6) for cleaning and collecting impurities on the metal filter screen (3312).

9. A paper drying and ventilation system according to claim 8, characterized in that: The impurity recovery device (6) includes a collection box (61) slidably disposed inside the hot air hood (2), a belt transmission mechanism (62) disposed between the hot air hood (2) and the collection box (61) and driving the collection box (61) to rotate back and forth, multiple brush rollers (63) rotatably connected to the top of the collection box (61), a linkage structure (64) disposed between the brush rollers (63) and the hot air hood (2) and driving the brush rollers (63) to rotate when the brush rollers (63) move to the metal filter screen (3312), a recovery box (65) disposed at one end of the hot air hood (2), and a negative pressure dust collector (66) communicating with the bottom of the recovery box (65). The top of the recovery box (65) is provided with a receiving pipe (651), and the bottom of the collection box (61) is provided with a recovery pipe (611) that is inserted into the receiving pipe (651) during movement.

10. A paper drying and ventilation system according to claim 9, characterized in that: The linkage structure (64) includes multiple gears (621) disposed at the end of the brush roller (63) and multiple racks (622) disposed at the top of the hot air cover (2). When the brush roller (63) moves to the range of the metal filter screen (3312), the gears (621) mesh with the racks (622) to drive the brush roller (63) to rotate.

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