Drying device

Abstract

The invention discloses a drying device which comprises a drying cylinder, an air supply assembly, a turbulent flow air pipe and a hot blast stove. The drying cylinder is provided with a drying runner in the vertical direction, the upper end of the drying runner is a feeding end, and the lower end of the drying runner is a discharging end. The air supply assembly comprises at least one sieve plate and multiple sets of air supply pipes, the sieve plates and the multiple sets of air supply pipes are alternately distributed in the drying runner in the vertical direction, all the air supply pipes are obliquely arranged upwards in the air supply direction of the air supply pipes, and the sieve plates are arranged between the two sets of air supply pipes. The turbulent flow air pipe is located in the drying flow channel, located between the adjacent air supply pipe and the sieve plate and arranged above the sieve plate, and the turbulent flow air pipe is obliquely arranged downwards in the air supply direction of the turbulent flow air pipe; the hot air furnace is provided with an air outlet pipe used for outputting hot air, and the air outlet pipe communicates with the air supply pipe and the turbulent flow air pipe. According to the scheme, the moving stroke of quartz sand in the drying flow channel can be increased, the quartz sand is dried through multiple times of air supply, the drying effect is improved, meanwhile, the quartz sand can be disturbed and dispersed without additionally arranging a motor and stirring blades, and the equipment cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of quartz sand drying equipment, and in particular to a drying device. Background Art

[0002] Quartz sand is the key foundation for the development of solar photovoltaic, optical fiber communication, electronic packaging, electric light source and high-end quartz glass industry. Quartz sand is usually processed through crushing, screening, rinsing and drying. The quartz sand drying method is to evaporate the water in the quartz sand by heating to obtain dry quartz sand.

[0003] Patent CN210663722U discloses a box-type quartz sand drying device, which starts the driving motor when working, and the stirring shaft rotates, so that the spiral blades stir the quartz sand to fully disperse the quartz sand. At the same time, during the stirring process, the material can be lifted upward, and the hot air nozzle generates hot air evenly downward, so that the hot air moves in the opposite direction to the quartz sand, and then the quartz sand can be completely dried.

[0004] However, this patent requires the installation of a motor and stirring blades to continuously stir the quartz sand, which increases the cost of the device. Summary of the invention

[0005] The purpose of the present invention is to overcome the above technical deficiencies and propose a drying device to solve the technical problem that the quartz sand drying device in the prior art needs to be equipped with a motor and stirring blades to continuously stir the quartz sand, which increases the cost of the device.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: The present invention provides a drying device, comprising: The drying cylinder is provided with a drying channel in the vertical direction, the upper end of which is the feeding end and the lower end is the discharging end; An air supply component, comprising a sieve plate and two groups of air supply pipes, wherein the two groups of air supply pipes are located in the drying flow channel and are arranged at intervals in the vertical direction, and each of the air supply pipes is arranged to be inclined upward along its air supply direction, wherein the sieve plate is placed between the two groups of air supply pipes, and the sieve holes thereof are arranged to extend in the vertical direction; A spoiler duct is located in the drying flow channel, is placed above the sieve plate, and is located below the adjacent air supply duct, and the spoiler duct is tilted downward along its air supply direction; and The hot air furnace is provided with an air inlet pipe and an air outlet pipe connected to the heating chamber thereof, wherein the air outlet pipe is connected to the air supply pipe and the spoiler air pipe respectively.

[0007] In some embodiments, the drying channel has a feed inlet at its upper end and a discharge outlet at its lower end; The air outlet pipe includes an air outlet main pipe and an air outlet branch pipe, one end of the air outlet main pipe is connected to the heating chamber of the hot air furnace, and the other end extends from the discharge port into the drying flow channel and penetrates the sieve plate, the air outlet branch pipe is located outside the drying cylinder, and one end of the air outlet branch pipe is connected to the air outlet main pipe, and the other end is placed above the sieve plate and below the adjacent air supply pipe; The air supply pipe is connected to the main air outlet pipe, and one end of the spoiler air pipe extends out of the drying channel and is connected to the outlet branch pipe, so as to be arranged in sequence with the air supply pipe along the radial direction of the drying channel.

[0008] In some embodiments, each group of the air supply pipes is provided with a plurality of air supply pipes in sequence along the circumference of the air outlet main pipe; and / or, One end of the air outlet branch pipe away from the air outlet main pipe is arranged around the outer circumference of the drying cylinder, and a plurality of the spoiler air ducts are arranged in sequence along the circumference of the drying cylinder.

[0009] In some embodiments, the air outlet duct also includes a connecting pipe and a sealing cover. The connecting pipe is connected to one end of the air outlet main pipe located outside the drying flow channel, extends in a vertical direction, and is provided with an external thread. The sealing cover is provided with an internal thread corresponding to the connecting pipe and can be screwed to the connecting pipe.

[0010] In some embodiments, the sieve plate is inclined downward from the periphery to the middle.

[0011] In some embodiments, a sieve plate is provided between any two adjacent groups of the air supply pipes; A plurality of spoiler ducts are provided corresponding to the sieve plates, and each spoiler duct is located above the corresponding sieve plate and below the adjacent air supply duct.

[0012] In some embodiments, the hot air furnace has an air inlet duct for supplying air, and the drying device also includes a return air duct, which is connected to the upper end of the drying flow channel and the air inlet duct.

[0013] In some embodiments, the drying device also includes a buffer tank, a collecting tank and a baffle. The buffer tank is arranged on the return air duct, and its inner diameter is larger than the inner diameter of the return air duct. A discharge port is provided at the bottom of the buffer tank. The collecting tank is connected to the discharge port. The baffle is arranged in the buffer tank and is opposite to the return air duct.

[0014] In some embodiments, two baffles are provided, and the two baffles are spaced apart along the hot air flow direction and located on two opposite sides of the discharge port, and the baffle close to the drying cylinder is spaced apart from the bottom of the buffer tank, and the baffle away from the drying cylinder is spaced apart from the top of the buffer tank; Wherein, a projection of each baffle plate toward another baffle plate at least partially falls on another baffle plate.

[0015] In some embodiments, the drying device further comprises a drying tank and a lime bed layer. The drying tank is arranged on the return air duct and is located on a side of the buffer tank away from the drying cylinder. The lime bed layer is placed in the drying tank.

[0016] Compared with the prior art, in the drying device provided by the present invention, the quartz sand to be dried is fed into the drying channel from the upper feed end. After entering the drying channel, the quartz sand to be dried is blown away by the hot air fed by the upper air supply pipe and continues to fall. When it falls to the position corresponding to the turbulent air duct, it is disturbed by the hot air fed by the turbulent air duct again and continues to fly, thereby increasing the moving stroke of the quartz sand. After being blown by the turbulent air duct, the quartz sand falls on the sieve plate, and falls through the sieve holes of the sieve plate, and is blown and dried by the hot air fed by the lower air supply pipe again, and finally the dried quartz sand is discharged through the discharging end. In this way, the moving stroke of the quartz sand in the drying channel can be increased, and the hot air fed by the upper air supply pipe, the turbulent branch pipe and the lower air supply pipe is dried in sequence, and multiple air supply drying is performed to improve the drying effect. At the same time, the quartz sand can be disturbed and dispersed without the need to additionally set up a motor and a stirring blade, thereby saving equipment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of a drying device provided in an embodiment of the present invention; Figure 2 yes Figure 1 A cross-sectional view of the drying device; Figure 3 yes Figure 2 Schematic diagram of the central air supply assembly, spoiler duct and air outlet duct; Figure 4 yes Figure 3 A partial schematic diagram of the central air supply assembly, spoiler duct and air outlet duct; Figure 5 yes Figure 2 Partial cross-sectional view of the center return air duct; Figure 6 This is a partial perspective view of the return air duct in 1.

[0018] Description of reference numerals: 1. Drying cylinder; 11. Drying flow channel; 12. Feed inlet; 13. Discharge outlet; 2. Sieve plate; 3. Air supply duct; 4. Turbine duct; 5. Hot air furnace; 51. Air inlet duct; 52. Air outlet duct; 521. Air outlet main pipe; 522. Air outlet branch pipe; 523. Connecting pipe; 524. Cover; 6. Return air duct; 61. Front return air duct; 62. Rear return air duct; 7. Buffer tank; 7a. Feed outlet; 71. Collecting tank; 72. Baffle; 8. Drying tank; 81. Lime bed. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] In order to solve the technical problem that the quartz sand drying device in the prior art needs to be equipped with a motor and stirring blades to continuously stir the quartz sand, which increases the cost of the device, the present invention provides a drying device that can improve the drying effect and can disturb and disperse the quartz sand without the need for additional motors and stirring blades, thereby saving equipment costs.

[0021] See also Figures 1 to 3 , Figures 1 to 3 It is a structural schematic diagram of a drying device in an embodiment of the present invention, the drying device comprises a drying cylinder 1, an air supply assembly, a spoiler duct 4 and a hot air furnace 5; the drying cylinder 1 is provided with a drying flow channel 11 along the vertical direction, the upper end of which is a feeding end, and the lower end is a discharging end; the air supply assembly comprises at least one sieve plate 2 and a plurality of groups of air supply ducts 3, the sieve plate 2 and the plurality of groups of air supply ducts 3 are alternately distributed along the vertical direction and built into the drying flow channel 11, each air supply duct 3 is arranged to be inclined upward along its air supply direction, and the sieve plate 2 is placed between the two groups of air supply ducts 3; the spoiler duct 4 is located in the drying flow channel 11, and is located between the adjacent air supply duct 3 and the sieve plate 2, and is arranged above the sieve plate 2, and the spoiler duct 4 is arranged to be inclined downward along its air supply direction; the hot air furnace 5 has an outlet duct 52 for outputting hot air, and the outlet duct 52 is respectively connected to the air supply duct 3 and the spoiler duct 4.

[0022] In the drying device provided by the present invention, the quartz sand to be dried is fed into the drying channel 11 from the upper feed end. After entering the drying channel 11, the quartz sand to be dried is blown away by the hot air fed by the upper air supply pipe 3 and continues to fall. When it falls to the position corresponding to the turbulent air pipe 4, it is disturbed by the hot air fed by the turbulent air pipe 4 again and continues to fly, thereby increasing the moving stroke of the quartz sand. After being blown by the turbulent air pipe 4, the quartz sand falls on the sieve plate 2, and falls through the sieve holes of the sieve plate 2, and is blown and dried by the hot air fed by the lower air supply pipe 3 again, and finally the dried quartz sand is discharged through the discharging end. In this way, the moving stroke of the quartz sand in the drying channel 11 can be increased, and the hot air drying fed by the upper air supply pipe 3, the turbulent branch pipe and the lower air supply pipe 3 is sequentially carried out, and multiple air supply drying is performed to improve the drying effect. At the same time, the quartz sand can be disturbed and dispersed without the need to additionally set up a motor and a stirring blade, thereby saving equipment costs.

[0023] In one embodiment, see Figure 3 and Figure 4 , a material inlet 12 is provided at the upper end of the drying channel 11, and a material outlet 13 is provided at the lower end thereof; the air outlet pipe 52 includes an air outlet main pipe 521 and an air outlet branch pipe 522, one end of the air outlet main pipe 521 is connected to the heating chamber of the hot air furnace 5, and the other end extends from the material outlet 13 into the drying channel 11 and is penetrated through the sieve plate 2, the air outlet branch pipe 522 is located outside the drying cylinder 1, and one end is connected to the air outlet main pipe 521, and the other end is placed above the sieve plate 2 and below the adjacent air supply pipe 3; the air supply pipe 3 is connected to the air outlet main pipe 521, and one end of the spoiler air duct 4 extends out of the drying channel 11 and is connected to the air outlet branch pipe 522, so as to be arranged in sequence with the air supply pipe 3 along the radial direction of the drying channel 11.

[0024] In this embodiment, the air supply duct 3 and the spoiler duct 4 are arranged in sequence along the radial direction of the drying channel 11, so that the hot air delivered by the air supply duct 3 and the spoiler duct 4 can cross and cover the entire drying channel 11, ensuring that the quartz sand can be driven to fly seamlessly by the hot air delivered by the two pipes during the downward movement, thereby making the quartz sand have a longer moving stroke in the drying channel 11, thereby improving the drying effect of the quartz sand.

[0025] In one embodiment, each group of air supply pipes 3 is sequentially provided along the circumference of the air outlet main pipe 521; the end of the air outlet branch pipe 522 away from the air outlet main pipe 521 is arranged around the outer periphery of the drying cylinder 1, and multiple spoiler air ducts 4 are sequentially arranged along the circumference of the drying cylinder 1.

[0026] In this embodiment, a plurality of air supply pipes 3 and flow-disturbing air pipes 4 are respectively arranged along the circumference of the drying channel 11 to improve the drying efficiency of the quartz sand. It should be noted that in this solution, a control valve is respectively arranged on the air outlet main pipe 521 and the air outlet branch pipe 522.

[0027] In one embodiment, the air outlet duct 52 also includes a connecting pipe 523 and a cover 524. The connecting pipe 523 is connected to one end of the air outlet main pipe 521 located outside the drying flow channel 11, and is extended in the vertical direction and has an external thread. The cover 524 has an internal thread corresponding to the connecting pipe 523 and can be screwed to the connecting pipe 523.

[0028] In this embodiment, a connecting pipe 523 is connected to the lower end of the air outlet main pipe 521, and the lower end of the connecting pipe 523 can be opened and closed by a cover 524. In this way, when the device is drying quartz sand normally, the lower end of the connecting pipe 523 is closed with the cover 524. At this time, because the air supply pipe 3 outputs hot air, the quartz sand dust in the drying flow channel 11 will not enter the hot air main pipe. When the device is shut down unexpectedly, the hot air stops being transported, and some of the dust that escaped in the drying flow channel 11 is easy to enter the air outlet main pipe 521 through the air supply pipe 3; at this time, the cover 524 can be opened, so that the dust accumulated in the air outlet main pipe 521 can be discharged through the connecting pipe 523, avoiding clogging of the air outlet main pipe 521.

[0029] In another embodiment, when the device is shut down normally, the conveying of the quartz sand to be dried into the drying channel 11 through the feed end is stopped first, and after continuing to convey hot air into the drying channel 11 for a preset time, the air supply is stopped, so that the quartz sand in the drying channel 11 can move completely downward and be discharged through the discharge port 13, thereby preventing the quartz sand from entering the air outlet main pipe 521 from the air supply pipe 3.

[0030] In one embodiment, the screen plate 2 is arranged to be inclined downward from the periphery to the middle.

[0031] In this embodiment, the sieve plate 2 is set to be tapered downward, so that the quartz sand on the sieve plate 2 can slide down on the wall of the sieve plate 2 under the drive of its own weight, so as to ensure that the quartz sand can be dispersed through the sieve holes, which is convenient for drying with hot air sent by the air supply pipe 3 below. It should be understood that the hot air sent by the spoiler air duct 4 can also promote the quartz sand to pass through the sieve plate 2 to a certain extent.

[0032] In one embodiment, a sieve plate 2 is provided between any two adjacent groups of air supply pipes 3 ; a plurality of spoiler air ducts 4 are provided corresponding to the sieve plates 2 , and each spoiler air duct 4 is located above the corresponding sieve plate 2 and below the adjacent air supply pipe 3 .

[0033] In this embodiment, a plurality of air supply components and spoiler air ducts 4 are arranged in sequence along the vertical direction to further improve the drying effect of the quartz sand.

[0034] Specifically, in this solution, two sieve plates 2 are arranged at intervals in the vertical direction, three groups of air supply pipes 3 are arranged, and the three groups of air supply pipes 3 are arranged alternately with the two sieve plates 2. Correspondingly, two groups of spoiler air ducts 4 are arranged.

[0035] In one embodiment, the hot air furnace 5 has an air inlet pipe 51 for supplying air, and the drying device further includes a return air pipe 6 , which is connected to the upper end of the drying channel 11 and the air inlet pipe 51 .

[0036] In this embodiment, a return air duct 6 is also provided to return the hot air in the drying channel 11 to the air inlet duct 51 of the hot air furnace 5 to preheat the fresh air, save energy and reduce costs. It should be noted that in this solution, a blower is provided on the air inlet duct 51.

[0037] In one embodiment, see Figure 5 and Figure 6 The drying device also includes a buffer tank 7, a collecting tank 71 and a baffle 72. The buffer tank 7 is arranged on the return air duct 6. Its inner diameter is larger than the inner diameter of the return air duct 6, and a discharge port 7a is arranged at its bottom. The collecting tank 71 is connected to the discharge port 7a. The baffle 72 is arranged in the buffer tank 7 and is directly opposite to the return air duct 6.

[0038] In this embodiment, a buffer tank 7 is further provided on the return air duct 6. When the hot air in the return air duct 6 enters the buffer tank 7, the flow rate of the hot air slows down due to the increase in space. When the hot air hits the baffle plate 72, the quartz sand dust entrained in the hot air is blocked and enters the collecting tank 71 through the discharge port 7a under the action of its own weight, while the hot air continues to flow along the return air duct 6 to the hot air furnace 5.

[0039] It should be noted that the hot air brought out from the drying flow channel 11 is dusty quartz sand, which has a relatively small particle size and is unqualified quartz sand, that is, the hot air recycling can also remove unqualified quartz sand. Specifically, in this solution, the part of the return air duct 6 located between the buffer tank 7 and the drying cylinder 1 is defined as the front section return air duct 61, and the front section return air duct 61 is at least partially tilted downward in the direction close to the buffer tank 7 to prevent the unqualified dusty quartz sand brought out by the hot air from flowing back into the drying cylinder 1.

[0040] In addition, the portion of the return air tank located between the buffer tank 7 and the air inlet duct 51 is defined as a rear return air duct 62 , and the portion of the rear return air duct 62 close to the buffer tank 7 is tilted downward in the direction close to the buffer tank 7 to prevent dust from entering the air inlet duct 51 .

[0041] In one of the embodiments, the buffer tank 7 is detachably connected to the return air duct 6. Specifically, a connecting plate can be set at the end of the return air duct 6 and the buffer tank 7, and the detachable connection can be achieved by bolts and flanges. The specific structure and principle are existing technologies and will not be elaborated here.

[0042] In one embodiment, two baffles 72 are provided, and the two baffles 72 are spaced apart along the hot air flow direction and are located on opposite sides of the discharge port 7a, and the baffle 72 close to the drying cylinder 1 is spaced apart from the bottom of the buffer tank 7, and the baffle 72 away from the drying cylinder 1 is spaced apart from the top of the buffer tank 7; wherein the projection of each baffle 72 onto another baffle 72 at least partially falls on the other baffle 72.

[0043] In this embodiment, two baffles 72 are provided in the buffer tank 7 as described above, so as to further improve the dust interception capability of the buffer tank 7 in the hot air, and effectively prevent the hot air from bringing the dust into the air inlet pipe 51 .

[0044] In one embodiment, the drying device further includes a drying tank 8 and a lime bed 81 . The drying tank 8 is disposed on the return air duct 6 and is located on a side of the buffer tank 7 away from the drying cylinder 1 . The lime bed 81 is placed in the drying tank 8 .

[0045] In this embodiment, a drying tank 8 is further arranged behind the buffer tank 7, and water vapor in the hot air is removed by the lime bed 81 in the drying tank 8, and the water vapor releases heat when reacting with the calcium oxide in the lime bed 81, which can increase the temperature of the hot air and promote the preheating of the fresh air. It should be noted that the lime bed 81 has good air permeability and can be arranged in a honeycomb or other air permeable structure. Its specific structure is a prior art and is not described in detail here.

[0046] In addition, in one embodiment, the drying tank 8 is detachably connected to the return air duct 6. Specifically, a connection plate can be provided at the end of the return air duct 6 and the drying tank 8, and a detachable connection is achieved through bolts and flanges. The specific structure and principle are prior art and are not described in detail here. In this way, the lime bed 81 can be taken out of the drying tank 8 regularly, placed in a high concentration carbon dioxide environment for a certain period of time, and then calcined at high temperature for reuse.

[0047] In order to better understand the present invention, the following Figures 1 to 6 The technical solution of the present invention is described in detail: The quartz sand to be dried is fed into the drying flow channel 11 from the feed port 12, and is first dried by the hot air fed by the upper air supply pipe 3, and then dried and blown by the hot air fed by the spoiler air pipe 4 during the downward movement, thereby increasing the movement stroke of the quartz sand; after being blown by the spoiler air pipe 4, the quartz sand falls on the sieve plate 2, is dispersed through the sieve holes on the sieve plate 2, and is dried again by the hot air fed by the lower air supply pipe 3. In addition, the quartz sand is further dried by the air supply components and spoiler air pipe 4 of other groups during the downward movement, thereby ensuring that the quartz sand is fully dried.

[0048] The hot air can also remove dusty quartz sand with smaller particle sizes, transport the dusty quartz sand from the drying channel 11 to the return air duct 6, and retain the dust in the collecting tank 71 on the return air duct 6. The hot air can also remove water vapor in the hot air when passing through the drying tank 8 to prevent the water vapor from circulating into the drying channel 11. The dried hot air finally enters the air inlet duct 51 to merge with the fresh air to preheat the fresh air and save energy.

[0049] The specific implementation of the present invention described above does not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A drying device, characterized in that: include: The drying cylinder is provided with a drying channel in the vertical direction, the upper end of which is the feeding end and the lower end is the discharging end; An air supply assembly, comprising at least one sieve plate and a plurality of air supply pipes, wherein the sieve plate and the plurality of air supply pipes are alternately distributed in a vertical direction and built into the drying flow channel, each of the air supply pipes is arranged to be inclined upward along its air supply direction, and the sieve plate is placed between two groups of the air supply pipes; A spoiler duct is located in the drying flow channel, and is located between the air supply duct and the sieve plate, and is arranged above the sieve plate, wherein the spoiler duct is arranged to be tilted downward along its air supply direction; and The hot air furnace is provided with an air outlet pipe for outputting hot air, and the air outlet pipe is respectively connected with the air supply pipe and the spoiler air pipe.

2. The drying device according to claim 1, characterized in that: The upper end of the drying channel is provided with a feed inlet, and the lower end thereof is provided with a discharge outlet; The air outlet pipe includes an air outlet main pipe and an air outlet branch pipe, one end of the air outlet main pipe is connected to the heating chamber of the hot air furnace, and the other end extends from the discharge port into the drying flow channel and penetrates the sieve plate, the air outlet branch pipe is located outside the drying cylinder, and one end of the air outlet branch pipe is connected to the air outlet main pipe, and the other end is placed above the sieve plate and below the adjacent air supply pipe; The air supply pipe is connected to the main air outlet pipe, and one end of the spoiler air pipe extends out of the drying channel and is connected to the outlet branch pipe, so as to be arranged in sequence with the air supply pipe along the radial direction of the drying channel.

3. The drying device according to claim 2, characterized in that: The air supply pipes of each group are provided in sequence along the circumference of the air outlet main pipe; and / or, One end of the air outlet branch pipe away from the air outlet main pipe is arranged around the outer circumference of the drying cylinder, and a plurality of the spoiler air ducts are arranged in sequence along the circumference of the drying cylinder.

4. The drying device according to claim 2, characterized in that: The air outlet duct also includes a connecting pipe and a sealing cover. The connecting pipe is connected to one end of the air outlet main pipe located outside the drying flow channel, extends in the vertical direction, and is provided with an external thread. The sealing cover is provided with an internal thread corresponding to the connecting pipe and can be screwed to the connecting pipe.

5. The drying device according to claim 1, characterized in that: The sieve plate is arranged to be inclined downward from the periphery to the middle.

6. The drying device according to claim 1, characterized in that: A sieve plate is provided between any two adjacent groups of air supply pipes; A plurality of spoiler ducts are provided corresponding to the sieve plates, and each spoiler duct is located above the corresponding sieve plate and below the adjacent air supply duct.

7. The drying device according to claim 1, characterized in that: The hot air furnace has an air inlet pipe for supplying air, and the drying device also includes a return air pipe, which is connected to the upper end of the drying flow channel and the air inlet pipe.

8. The drying device according to claim 7, characterized in that: The drying device also includes a buffer tank, a collecting tank and a baffle. The buffer tank is arranged on the return air duct, and its inner diameter is larger than the inner diameter of the return air duct. A discharge port is provided at the bottom of the buffer tank. The collecting tank is connected to the discharge port. The baffle is arranged in the buffer tank and is opposite to the return air duct.

9. The drying device according to claim 8, characterized in that: There are two baffles, which are spaced apart along the hot air flow direction and located on two opposite sides of the discharge port, and the baffle close to the drying cylinder is spaced apart from the bottom of the buffer tank, and the baffle away from the drying cylinder is spaced apart from the top of the buffer tank; Wherein, a projection of each baffle plate toward another baffle plate at least partially falls on another baffle plate.

10. The drying device according to claim 8, characterized in that: The drying device further comprises a drying tank and a lime bed layer. The drying tank is arranged on the return air duct and is located on a side of the buffer tank away from the drying cylinder. The lime bed layer is placed in the drying tank.

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