Multi-layer self-cleaning S-shaped mesh belt type drying machine

Abstract

The invention discloses a multi-layer self-cleaning S-shaped mesh belt type drying machine, and relates to the technical field of drying. The material conveying device comprises a plurality of material conveying mesh belts which are vertically arranged and arranged in a drying box, the discharging end of the upper material conveying mesh belt is arranged above the feeding side of the lower adjacent material conveying mesh belt, the material conveying mesh belts are horizontally arranged in parallel, the feeding ends of the material conveying mesh belts stretch out of the drying box, and the discharging ends of the material conveying mesh belts are arranged in parallel. A cleaning mechanism is arranged below the feeding end, and the cleaning end of the cleaning mechanism is used for cleaning the lower mesh belt of the feeding end; the problems that according to an existing multi-layer S-shaped mesh belt drying machine, a mesh belt cannot be cleaned online, and mesh sticking materials are difficult to remove are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of drying, and specifically, to a multi-layer self-cleaning S-shaped mesh belt dryer. Background Art

[0002] As a continuous drying equipment, the multi-layer mesh belt dryer is widely used in the field of agricultural product processing (such as dried fruits, aquatic products, Chinese herbal medicines, fruit residues, etc.) due to its high production capacity, high thermal efficiency and intensive floor area. However, for materials with high moisture, high sugar content or viscous components, the existing equipment generally faces many technical bottlenecks during long-term operation.

[0003] For example, at the initial stage of drying, due to the precipitation of surface free water or the melting of sugar by heat, the material is likely to adhere to the surface of the mesh belt, forming local lumps. As the drying process progresses, the viscous substances continuously deposit in the pores of the mesh belt, resulting in a significant decrease in air permeability. This not only causes uneven heating of the material and affects the consistency of the moisture content of the finished product, but also forces the equipment to stop frequently for manual mesh cleaning, seriously restricting the continuous production capacity.

[0004] Another example is in scenarios where strict purity requirements are imposed on Chinese herbal medicines and the like. The traditional mesh belt structure lacks an effective material isolation mechanism. Trace components (such as volatile oils, alkaloids, etc.) remaining in the pores of the mesh belt are likely to migrate to the subsequent batch of materials under high-temperature conditions, resulting in problems such as drug mixing or cross-taste. The existing technology relies on high-pressure water flushing or chemical cleaning after shutdown, which not only increases energy consumption, but also causes controversy over secondary pollution due to the residue of cleaning agents.

[0005] The mechanical scraper mesh cleaning scheme commonly used in the industry has two major defects: First, the rigid scraper in contact with the mesh belt is likely to cause metal fatigue damage; second, the cleaning efficiency of deep adhesives in micron-sized pores is insufficient. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-layer self-cleaning S-shaped mesh belt dryer to solve the problems that the existing multi-layer S-shaped mesh belt dryer cannot clean the mesh belt online and it is difficult to remove the sticky mesh materials.

[0007] To solve the above problems, the present invention adopts the following technical means: A multi-layer self-cleaning S-shaped mesh belt dryer includes a plurality of feeding mesh belts arranged vertically and disposed inside a drying box. The discharging end of the upper feeding mesh belt is disposed above the feeding side of the adjacent lower feeding mesh belt. The feeding end of the feeding mesh belt extends out of the drying box, and a cleaning mechanism is disposed below the feeding end. The cleaning end of the cleaning mechanism is used to clean the lower mesh belt at the feeding end.

[0008] Preferably, the feeding mesh belts are horizontally and parallel to each other.

[0009] Further, a through-channel for the feeding end of the conveying mesh belt to pass through is formed on the side wall of the drying oven. An isolation and sealing plate is installed in the through-channel and is arranged between the upper mesh belt and the lower mesh belt of the conveying mesh belt.

[0010] Furthermore, a downward-inclined baffle is formed in the drying oven, and the inclined surface of the downward-inclined baffle faces the discharging end of the conveying mesh belt.

[0011] Furthermore, the bottom end of the downward-inclined baffle is arranged in a fitting manner with the top surface of the upper mesh belt of the conveying mesh belt, and a buffer area is formed between the side of the downward-inclined baffle facing away from the discharging end and the inner wall of the drying oven.

[0012] Furthermore, the cleaning mechanism includes a high-pressure spray head, a brush, and a water tank with an open top. The water spraying end of the high-pressure spray head is arranged facing the lower mesh belt at the feeding end, the bristled side of the brush is in contact with the lower mesh belt at the feeding end, and the water tank is arranged below the high-pressure spray head and the brush.

[0013] Furthermore, the high-pressure spray head is arranged between the upper mesh belt and the lower mesh belt of the conveying mesh belt, and the high-pressure spray head is arranged on the upstream side of the brush.

[0014] Furthermore, the bottom surface of the brush is arranged below the liquid level in the water tank.

[0015] Furthermore, the cleaning mechanism further includes a cold shrinkage box and a heat expansion box. The cold shrinkage box, the heat expansion box, and the high-pressure spray head are arranged in sequence along the mesh belt moving direction of the conveying mesh belt. The lower mesh belt of the conveying mesh belt passes through the cold shrinkage box and the heat expansion box in sequence. The cold shrinkage box is used to cool the lower mesh belt, the inner cavity of the heat expansion box is communicated with the humid and hot gas exhaust end of the drying oven, and the heat expansion box is used to heat and humidify the lower mesh belt.

[0016] Furthermore, the cold shrinkage box includes a first heat insulation box with through openings formed at both ends for the lower mesh belt to pass through. A containing cavity for placing dry ice is formed at the inner top of the first heat insulation box. The containing cavity is arranged above the lower mesh belt, and a through opening for a pipe to pass through is formed at the bottom surface of the containing cavity. The heat expansion box includes a second heat insulation box with through openings formed at both ends for the lower mesh belt to pass through. An air inlet pipe communicated with the humid and hot gas exhaust end is connected to the bottom surface of the second heat insulation box, and an exhaust pipe is connected to the top surface of the second heat insulation box.

[0017] The present invention has the following beneficial effects during use: The material gradually falls downward from the topmost feeding conveyor belt inside the drying oven. The material is dried from top to bottom along the feeding conveyor belt inside the drying oven. The material makes an S-shaped sectional movement along with the operation of the feeding conveyor belt inside the drying oven and finally is output from the bottommost conveyor belt. The upper conveyor belt of each feeding conveyor belt is used to convey the material. The material is conveyed from the upper conveyor belt of the upper feeding conveyor belt to the upper conveyor belt of the lower feeding conveyor belt until it is unloaded from the drying oven. Along with the operation of the feeding conveyor belt, after the upper conveyor belt finishes conveying the material, it is transferred to the lower conveyor belt. And on the side of the lower conveyor belt, the side conveyor belt moves from the discharge end to the feed end. Since the feed end of the feeding conveyor belt and the cleaning mechanism are arranged outside the drying oven, and the cleaning mechanism is used to clean the lower conveyor belt, the cleaned lower conveyor belt is transferred to the upper conveyor belt as it moves. And the cleaned upper conveyor belt can enter the drying oven from outside the drying oven along with the operation of the feeding conveyor belt to receive the material falling from the upper feeding conveyor belt, ensuring the normal progress of the drying operation. In this way, the drying operation is carried out inside the drying oven, while the cleaning operation is independently carried out outside the drying oven, enabling the system to clean the conveyor belt online while drying, achieving the effect of simultaneous cleaning and drying, avoiding the adhesion and accumulation of materials during the drying process, and always ensuring the ventilation of the feeding conveyor belt to ensure the effect of the drying operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic structural diagram of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the cold shrinkage box in an embodiment of the present invention.

[0020] Figure 3 It is a schematic structural diagram of the thermal expansion box in an embodiment of the present invention.

[0021] Among them, 1 - drying oven, 2 - feeding conveyor belt, 3 - discharge end, 4 - feed end, 5 - cleaning mechanism, 6 - isolation and sealing plate, 7 - downward inclined baffle, 8 - buffer zone, 9 - high-pressure spray head, 10 - brush, 11 - water tank, 12 - cold shrinkage box, 13 - thermal expansion box, 14 - first heat insulation box, 15 - accommodation cavity, 16 - through port, 17 - second heat insulation box, 18 - intake pipe, 19 - exhaust pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0023] Accordingly, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0024] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other.

[0025] It should be noted that like reference numerals and letters denote like items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0026] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use, or the orientation or positional relationship commonly understood by those skilled in the art. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0027] In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0028] Please refer to Figure 1 As shown, a multi-layer self-cleaning S-type mesh belt dryer includes a plurality of conveying mesh belts 2 arranged vertically and disposed in a drying chamber 1. The feeding end 4 of the conveying mesh belt 2 at the uppermost position serves as the feeding side of the dryer. The material to be dried falling from the feeding machine drops to the feeding side and enters the drying chamber 1. The discharging end 3 of the conveying mesh belt 2 at the lowermost position serves as the discharging side of the dryer. The material falling from the lowermost conveying mesh belt 2 falls into the discharging conveyor and is sent out of the drying chamber 1 through the discharging conveyor. The discharge end 3 of the above-mentioned material conveying mesh belt 2 is arranged above the feeding side of the adjacent lower material conveying mesh belt 2, and the material conveying mesh belts 2 are horizontally and parallel to each other. Here, the discharge end 3 refers to the end where the material is conveyed along the material conveying mesh belt 2 and drops from the material conveying mesh belt 2, while the feeding side is the mesh belt on the material conveying mesh belt 2 close to the feeding end 4; furthermore, after the material enters the drying box 1, along the conveying direction of the material conveying mesh belt 2, it continuously drops from the upper material conveying mesh belt 2 into the lower material conveying mesh belt 2, so that the material makes an S-shaped section movement in the drying box 1 as the material conveying mesh belt 2 runs.

[0029] Furthermore, the feeding end 4 of the material conveying mesh belt 2 extends out of the drying box 1, and a cleaning mechanism 5 is arranged below the feeding end 4. The cleaning end of the cleaning mechanism 5 is used to clean the lower mesh belt of the feeding end 4.

[0030] In this way, the material gradually drops downward from the uppermost material conveying mesh belt 2 in the drying box 1. The material is dried from top to bottom along the material conveying mesh belt 2 in the drying box 1. The material makes an S-shaped section movement in the drying box 1 as the material conveying mesh belt 2 runs, and finally is output from the lowermost mesh belt. The upper mesh belt of each material conveying mesh belt 2 is used to convey the material. The material is conveyed from the upper mesh belt of the upper material conveying mesh belt 2 to the upper mesh belt of the lower material conveying mesh belt 2 until it is discharged from the drying box 1. Along with the running of the material conveying mesh belt 2, after the upper mesh belt completes the material conveying, it is transferred to the lower mesh belt. And on the side of the lower mesh belt, the mesh belt moves from the discharge end 3 to the feeding end 4. Since the feeding end 4 of the material conveying mesh belt 2 and the cleaning mechanism 5 are arranged outside the drying box 1, and the cleaning mechanism 5 is used to clean the lower mesh belt, the cleaned lower mesh belt is transferred to the upper mesh belt as it moves. And the cleaned upper mesh belt can enter the drying box 1 from outside the drying box 1 as the material conveying mesh belt 2 runs, for receiving the material falling from the upper material conveying mesh belt 2, ensuring the normal progress of the drying operation. In this way, the drying operation is carried out in the drying box 1, while the cleaning operation is carried out independently outside the drying box 1, enabling the system to clean the mesh belt online while drying, achieving the effect of cleaning and drying simultaneously, avoiding the adhesion and accumulation of materials during the drying process, and being able to always ensure the ventilation of the material conveying mesh belt 2, ensuring the effect of the drying operation.

[0031] In addition, a through channel for the feeding end 4 of the material conveying mesh belt 2 to pass through is constructed on the side wall of the drying box 1, so that the feeding end 4 of the material conveying mesh belt 2 can smoothly extend out of the drying box 1. In order to prevent the liquid generated during the cleaning of the mesh belt by the cleaning mechanism 5 from splashing into the drying box 1, an isolation sealing plate 6 is installed in the through channel. The isolation sealing plate 6 is arranged between the upper mesh belt and the lower mesh belt of the material conveying mesh belt 2. Thus, the through channel is blocked by the isolation sealing plate 6, leaving only the gaps for the upper mesh belt and the lower mesh belt of the material conveying mesh belt 2 to pass through in the through channel, and also being able to ensure that the temperature in the drying box 1 does not fluctuate greatly.

[0032] Furthermore, a downward-inclined baffle 7 is constructed inside the drying oven 1, and the inclined surface of the downward-inclined baffle 7 faces the discharge end 3 of the material conveying mesh belt 2.

[0033] The downward-inclined baffle 7 provided here is used to prevent the material from hitting the inner wall of the drying oven 1 due to inertia during the process of falling from the upper material conveying mesh belt 2 to the lower material conveying mesh belt 2.

[0034] Meanwhile, the bottom end of the downward-inclined baffle 7 is arranged in contact with the top surface of the upper mesh belt of the material conveying mesh belt 2, and a buffer area 8 is constructed between the side of the downward-inclined baffle 7 facing away from the discharge end 3 and the inner wall of the drying oven 1.

[0035] In this way, after the downward-inclined baffle 7 is set, due to the setting of the downward-inclined baffle, the material falling from the upper material conveying mesh belt 2 to the lower material conveying mesh belt 2 can hit the downward-inclined baffle 7 and then slide down along the inclined surface of the downward-inclined baffle 7 onto the lower material conveying mesh belt 2. In this way, when the material contacts the upper mesh belt of the lower material conveying mesh belt 2, it can be far away from the side wall of the drying oven 1, that is, it contacts the upper mesh belt at a position far away from the aforementioned through channel. Furthermore, after the mesh belt is cleaned and enters the drying oven 1, before the upper mesh belt contacts the falling material, the upper mesh belt moves in the buffer area 8 between the inner wall of the drying oven 1 and the downward-inclined baffle 7, so that when the upper mesh belt moves in the buffer area 8, it can be preheated and dried using the heat in the drying oven 1, avoiding a large amount of liquid remaining on the upper mesh belt due to cleaning by the cleaning mechanism 5.

[0036] Moreover, by arranging the bottom end of the downward-inclined baffle 7 in contact with the upper mesh belt, for some relatively large but small-area droplets remaining on the upper mesh belt, the downward-inclined baffle 7 can be used to scrape these liquids that have not been dried in the aforementioned buffer area 8. On the one hand, by scraping and blocking, it can be prevented from contacting the material falling from above through the downward-inclined baffle 7; on the other hand, by scraping and flattening, the contact area between the droplets and the mesh belt can be increased, increasing the heating area and thus accelerating drying.

[0037] Therefore, through the setting of the downward-inclined baffle 7, it can effectively avoid the situation that the liquid remaining on the mesh belt outside the drying oven 1 by the cleaning mechanism 5 during the online cleaning of the mesh belt affects the dried material. Ensure that online drying will not affect the drying process of the material.

[0038] For the cleaning mechanism 5, the cleaning mechanism 5 includes a high-pressure nozzle 9, a brush 10, and a water tank 11 with an open top; The water spraying end of the high-pressure nozzle 9 faces the lower mesh belt at the feeding end 4, the bristles side of the brush 10 is in contact with the lower mesh belt at the feeding end 4, and the water tank 11 is arranged below the high-pressure nozzle 9 and the brush 10.

[0039] Meanwhile, the high-pressure spray head 9 is disposed between the upper conveyor belt and the lower conveyor belt of the material conveying conveyor belt 2, and the high-pressure spray head 9 is disposed on the upstream side of the brush 10.

[0040] In this way, during the cleaning process of the lower conveyor belt, first use the water spray of the high-pressure spray head 9 to wash the materials adhered to the conveyor belt, preparing for the scraping and cleaning of the brush 10; then use the brushing of the brush 10 to scrape off the materials adhered to the conveyor belt, and use the water tank 11 to collect the sprayed water and the scraped residues.

[0041] Among them, the rotation direction of the brush 10 is opposite to the movement direction of the conveyor belt, thereby enhancing the cleaning effect of the brush 10 on the conveyor belt.

[0042] Furthermore, the bottom surface of the brush 10 is disposed below the liquid level in the water tank 11.

[0043] In this way, not only can the liquid in the water tank 11 be used to clean the cleaned brush 10 to avoid a large amount of residues remaining on the brush 10, but also the brush 10 can be provided with a cleaning solution to make the cleaning of the conveyor belt by the brush 10 more thorough.

[0044] In a preferred embodiment of the present invention, based on the foregoing description, please further combine Figure 2 and Figure 3 As shown, the cleaning mechanism 5 further includes a cold shrinkage box 12 and a thermal expansion box 13. The cold shrinkage box 12, the thermal expansion box 13 and the high-pressure spray head 9 are sequentially arranged along the conveyor belt moving direction of the material conveying conveyor belt 2; The lower conveyor belt of the material conveying conveyor belt 2 sequentially passes through the cold shrinkage box 12 and the thermal expansion box 13. The cold shrinkage box 12 is used to cool the lower conveyor belt, and the inner cavity of the thermal expansion box 13 is communicated with the humid and hot gas exhaust end of the drying box 1. The thermal expansion box 13 is used to heat and humidify the lower conveyor belt.

[0045] Among them, before the high-pressure spray head 9 acts on the conveyor belt, the conveyor belt first passes through the cold shrinkage box 12 and the thermal expansion box 13 in sequence.

[0046] For the cold shrinkage box 12, the cold shrinkage box 12 is used to cool the mesh belt. When the mesh belt passes through the cold shrinkage box 12, the mesh belt that was originally heated in the drying box 1 is quickly cooled. On the one hand, the temperature of the mesh belt is reduced to prepare for subsequent operations in the thermal expansion box 13. On the other hand, after the mesh belt is quickly cooled in the cold shrinkage box 12, using the thermal expansion and contraction characteristics of the metal mesh belt, the mesh belt can contract. In this way, for some materials embedded in the mesh holes, the water content of the embedded materials is relatively low and the brittleness is relatively large. When the mesh belt contracts rapidly due to cooling, the mesh holes will also contract. Then, the contraction of the mesh holes is used to slightly squeeze the dry materials embedded in the mesh holes, causing partial cracks on the surface or inside of the embedded dry materials. For the subsequent thermal expansion box 13, it can reduce the embedding effect between the materials embedded in the mesh holes and the mesh holes, and then facilitate the subsequent flushing of the materials in the mesh holes by the high-pressure nozzle 9.

[0047] For the thermal expansion box 13, the thermal expansion box 13 is used to heat the mesh belt. The heat source for the thermal expansion box 13 to heat the mesh belt comes from the high-temperature and humid gas discharged from the drying box 1. Such a heat source can not only realize the reuse of energy, but most importantly, it can not only heat the mesh belt. After the large amount of moisture carried in the gas contacts the mesh belt cooled by the cold shrinkage box 12, it can condense on the surface of the mesh belt. Thus, a liquid film covers the surface of the mesh belt. Furthermore, through the setting of the thermal expansion box 13, on the one hand, the cold-shrunk mesh belt is heated, causing the mesh belt to expand due to heat, so that the mesh holes also expand, while the materials clamped in the mesh holes remain unchanged. After the materials are extruded with partial cracks, the expansion of the mesh holes can reduce the extrusion effect between them and the embedded materials, making the materials in the mesh holes become loose. When the subsequent high-pressure nozzle 9 sprays, the materials embedded in the mesh holes can better escape from the mesh holes, thereby improving the cleaning efficiency of the mesh holes; on the other hand, using the condensed liquid film covering the surface of the mesh belt, the materials adhered to the mesh belt can be soaked, reducing the adhesion force between the materials adhered to the mesh belt and the mesh belt, so as to facilitate the subsequent cleaning of the materials adhered to the surface of the materials by the brush 10, thereby improving the cleaning effect of the brush 10.

[0048] More specifically, for the cold shrinkage box 12, the cold shrinkage box 12 includes a first heat insulation box 14 with through openings for the lower mesh belt to pass through at both ends. An accommodation cavity 15 for placing dry ice is constructed on the inner top of the first heat insulation box 14. The accommodation cavity 15 is located above the lower mesh belt, and a through opening 16 for passing through a pipe is constructed on the bottom surface of the accommodation cavity 15; Among them, by placing dry ice in the accommodation cavity 15, since the density of dry ice is greater than that of air, after sublimation, dry ice can not only use the heat absorption during sublimation to cool the inside of the cold shrinkage box 12; the lower-temperature gas after sublimation can pass through the through opening 16 and fall, and then contact the mesh belt passing through the cold shrinkage box 12 to further cool the mesh belt.

[0049] For the thermal expansion box 13, the thermal expansion box 13 includes a second heat insulation box 17 with openings at both ends for the lower mesh belt to pass through. An intake pipe 18 communicating with the exhaust end of the wet and hot gas is connected to the bottom surface of the second heat insulation box 17, and an exhaust pipe 19 is connected to the top surface of the second heat insulation box 17.

[0050] In this way, by supplying gas from bottom to top, the mesh belt passing through the thermal expansion box 13 can better contact the high-temperature wet and hot gas, facilitating the formation of a liquid film on the surface of the mesh belt and enabling the mesh belt to be heated well.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A multi-layer self-cleaning S-type mesh belt dryer, characterized in that: The invention comprises a plurality of conveyor mesh belts (2) arranged vertically and arranged in a drying box (1), wherein the discharge end (3) of the upper conveyor mesh belt (2) is arranged above the feed side of the lower adjacent conveyor mesh belt (2), and the conveyor mesh belts (2) are arranged horizontally and parallel to each other, and the feed end (4) of the conveyor mesh belt (2) extends out of the drying box (1), and a cleaning mechanism (5) is arranged below the feed end (4), and the cleaning end of the cleaning mechanism (5) is used to clean the lower mesh belt of the feed end (4).

2. A multi-layer self-cleaning S-type mesh belt dryer according to claim 1, characterized in that: The side wall of the drying box (1) is configured with a through passage for the feed end (4) of the conveyor mesh belt (2) to pass through, an isolation sealing plate (6) is installed in the through passage, and the isolation sealing plate (6) is arranged between the upper mesh belt and the lower mesh belt of the conveyor mesh belt (2).

3. A multi-layer self-cleaning S-type mesh belt dryer according to any one of claims 1 or 2, characterized in that: A downward-inclined baffle plate (7) is constructed in the drying box (1), and the inclined surface of the downward-inclined baffle plate (7) faces the discharge end (3) of the conveyor mesh belt (2).

4. A multi-layer self-cleaning S-shaped mesh belt dryer according to claim 3, characterized in that: The bottom end of the downwardly inclined baffle plate (7) is arranged to fit the top surface of the upper mesh belt of the conveyor mesh belt (2), and a buffer zone (8) is constructed between a surface of the downwardly inclined baffle plate (7) facing away from the discharge end (3) and the inner wall of the drying box (1).

5. The multi-layer self-cleaning S-shaped mesh belt dryer according to claim 1, characterized in that: The cleaning mechanism (5) comprises a high-pressure nozzle (9), a brush (10) and a water tank (11) with an open top surface; The water spraying end of the high-pressure nozzle (9) is arranged toward the lower mesh belt of the feed end (4), the bristle side of the brush (10) is arranged in contact with the lower mesh belt of the feed end (4), and the water tank (11) is arranged below the high-pressure nozzle (9) and the brush (10).

6. A multi-layer self-cleaning S-shaped mesh belt dryer according to claim 5, characterized in that: The high-pressure nozzle (9) is arranged between the upper belt and the lower belt of the conveying mesh belt (2), and the high-pressure nozzle (9) is arranged on the upstream side of the brush (10).

7. A multi-layer self-cleaning S-type mesh belt dryer according to claim 5 or 6, characterized in that: The bottom surface of the brush (10) is arranged below the liquid level in the water tank (11).

8. The multi-layer self-cleaning S-shaped mesh belt dryer according to claim 5, characterized in that: The cleaning mechanism (5) further comprises a cold shrink box (12) and a hot expansion box (13), wherein the cold shrink box (12), the hot expansion box (13) and the high-pressure nozzle (9) are sequentially arranged along the moving direction of the conveying mesh belt (2); The lower mesh belt of the conveying mesh belt (2) passes through the cold shrink box (12) and the thermal expansion box (13) in sequence. The cold shrink box (12) is used to cool the lower mesh belt. The inner cavity of the thermal expansion box (13) is connected to the hot and humid air exhaust end of the drying box (1). The thermal expansion box (13) is used to heat and humidify the lower mesh belt.

9. A multi-layer self-cleaning S-shaped mesh belt dryer according to claim 8, characterized in that: The shrink box (12) comprises a first heat-insulating box (14) with through openings at both ends for the lower mesh belt to pass through, a receiving chamber (15) for placing dry ice is configured on the inner top of the first heat-insulating box (14), the receiving chamber (15) is arranged above the lower mesh belt, and a through opening (16) for passing a pipe is configured on the bottom surface of the receiving chamber (15).

10. The multi-layer self-cleaning S-shaped mesh belt dryer according to claim 8, characterized in that: The thermal expansion box (13) comprises a second thermal insulation box (17) having openings at both ends for the lower mesh belt to pass through, the bottom surface of the second thermal insulation box (17) being connected to an air inlet pipe (18) connected to an exhaust end of the hot and humid air, and the top surface of the second thermal insulation box (17) being connected to an exhaust pipe (19).

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