Multi-layer circulating dryer and working method thereof

Abstract

The invention provides a multi-layer circulating dryer and a working method thereof, and relates to the field of dryers, the multi-layer circulating dryer comprises a box body, the upper part of the box body is provided with a feeding groove, two ends of the lower part of the box body are respectively provided with a circulating discharging groove and a main discharging groove, and the circulating discharging groove and the feeding groove are located at the same end of the box body; a lifting assembly is arranged between the feeding groove and the circulating discharging groove. N layers of conveying assemblies are further horizontally arranged in the box body, the conveying directions of every two adjacent layers of conveying assemblies are opposite, the conveying assembly on the uppermost layer is located below the feeding groove, the conveying assembly on the lowermost layer can conduct forward conveying and reverse conveying, when the conveying assembly on the lowermost layer conducts forward conveying, materials can be conveyed to the circulating discharging groove, and when the conveying assembly on the lowermost layer conducts reverse conveying, the materials can be conveyed to the circulating discharging groove. And when the conveying assembly on the lowermost layer conveys the materials reversely, the materials can be conveyed to the main discharging groove. According to the invention, the next production link can be automatically accessed while circular drying is realized, and the device is more suitable for an automatic production line.

Description

Technical Field

[0001] This invention relates to the field of dryers, and more particularly to a multi-layer circulating dryer and its operating method. Background Technology

[0002] Puffed foods are made from grains, beans, potatoes, vegetables, etc., and are processed by puffing equipment to produce a wide variety of puffed foods. After being shaped, puffed foods need to be placed in a drying device to remove some of the moisture in order to dry and set their shape. For some puffed foods with a delicate surface, dense texture, and poor internal air passages, low-temperature multiple-cycle drying is required. If they are dehydrated and dried quickly, the surface will crack, affecting their appearance and taste.

[0003] In the prior art, to meet the drying requirements of puffed foods with the above characteristics, a multi-layer drying device is provided, including a box body. Five layers of conveying components are horizontally arranged inside the box body. The conveying directions of two adjacent conveying components are opposite, and the conveying ends and feeding troughs of two adjacent conveying components are staggered. A feeding trough and a discharging trough are respectively provided at the upper and lower parts of the box body, respectively, and are located at both ends of the box body. A lifting component is provided between the feeding trough and the discharging trough. During operation, the material enters the box body through the feeding trough, and is simultaneously dried and conveyed downwards to the discharging trough by the multi-layer conveying components. Then, the lifting component returns the material to the feeding trough for further drying.

[0004] As puffed food production lines rapidly evolve towards automation and continuous operation, various production processes are now connected in series using specialized conveying equipment. However, when applying these technologies in production lines, the structural design of the discharge chute directly connecting to the lifting assembly makes seamless integration between this process and the conveying equipment in the next production stage difficult. In actual production, the lifting assembly must be manually moved before the subsequent conveying equipment can be connected and debugged. This operation not only interrupts the continuous operation of the production line and significantly reduces overall production efficiency but also increases labor costs, hindering the full realization of the production line's automation level. Summary of the Invention

[0005] To address the technical problem that existing dryers cannot seamlessly connect with the conveying equipment in the next stage of the production line, this invention provides a multi-layer circulating dryer and its operating method, which can automatically connect to the next production stage while achieving circulating drying, making it more suitable for automated production lines.

[0006] In a first aspect, the present invention provides a multi-layer circulating dryer to solve the above-mentioned technical problems, comprising a housing, a feeding trough being provided at the upper part of the housing, and a circulating discharge trough and a main discharge trough being provided at the lower two ends of the housing, the circulating discharge trough and the feeding trough being located at the same end of the housing, a lifting component being provided between the feeding trough and the circulating discharge trough, and the main discharge trough being used to connect to a corresponding conveying device; N layers of conveying components are also horizontally arranged inside the housing, the conveying directions of adjacent layers of conveying components are opposite, the uppermost layer of conveying components is located below the feeding trough, and the lowermost layer of conveying components can convey in both forward and reverse directions. When the lowermost layer of conveying components conveys in the forward direction, it can convey the material to the circulating discharge trough; when the lowermost layer of conveying components conveys in the reverse direction, it can convey the material to the main discharge trough.

[0007] This invention, by setting up a conveying component capable of forward and reverse rotation, a circulating discharge trough, and a main discharge trough, can realize internal circulating drying and dried material discharge according to process requirements without manual intervention to adjust the position of the lifting component. This solves the problem of process interruption caused by moving the lifting component in the prior art, ensuring the continuity of the drying process and achieving seamless integration with automated production lines. It significantly improves production efficiency, reduces labor costs, and is more suitable for the high-efficiency and intelligent production needs of modern food processing.

[0008] Furthermore, the lifting assembly adopts a C-type bucket elevator, which includes a feed inlet and a discharge outlet. The feed inlet is located below the circulating discharge trough, and the discharge outlet is located above the feeding trough.

[0009] Furthermore, the feeding trough is equipped with a material distributor, and the discharge port is located above the material distributor.

[0010] This invention uses a material spreader to ensure that the material is laid flat on the conveying assembly, thereby improving drying efficiency and drying effect.

[0011] Furthermore, the number of layers of the conveying component is N, where N is an even number.

[0012] This invention arranges the conveying components in an even number of layers. On the one hand, the bottommost conveying component can extend the drying path during internal circulation drying and play a drying role. On the other hand, when it needs to be transferred to the next stage, it can shorten the conveying path and improve the conveying efficiency.

[0013] Furthermore, an air inlet duct and a return air duct are provided on the outside of the housing. A circulating fan is provided on the air inlet duct, and a dehumidifying fan is provided on the upper part of the return air duct. The air inlet duct has multiple air inlets along its height direction, and the air inlets are located below the corresponding conveying components. The return air duct has multiple return air inlets along its height direction, and the return air inlets are located above the corresponding conveying components.

[0014] Furthermore, the lower part of the bottommost conveying assembly is provided with at least two air inlets.

[0015] This invention increases the air volume at the bottom layer by setting two air inlets, thereby enhancing the drying effect on the material at the bottom layer and improving drying efficiency.

[0016] Furthermore, both the air inlet duct and the air return duct are provided with air guide plates at their lower ends, and the air guide plates are inclined.

[0017] Furthermore, a combustion assembly is also provided at the upper part of the air inlet duct, and the combustion assembly can be connected to a natural gas source.

[0018] This invention improves drying efficiency by incorporating a combustion component that can heat air.

[0019] Furthermore, the conveying assembly has four layers. The conveying assembly in the first layer and the conveying assembly in the third layer share a drive component one. The conveying assembly in the second layer is connected to a drive component two. The conveying assembly in the fourth layer is the lowest layer of the conveying assembly and is connected to a drive component three, which is capable of rotating in both forward and reverse directions.

[0020] This invention reduces the number of drive components required and lowers the cost of the equipment by sharing drive components.

[0021] Secondly, the present invention also provides a method for operating a multi-layer circulating dryer, which employs the aforementioned multi-layer circulating dryer and includes the following steps: S01: The circulating fan and dehumidifying fan start, the feeding trough is fed, and the multi-layer conveying components work together to transport the material from the top layer to the bottom layer; S02: When circulating drying is required, open the lifting component and control the bottom conveying component to rotate in the forward direction. The material enters the lifting component from the circulating discharge trough and returns to the feeding trough for drying again. S03: Circulate S02 until the material's dryness meets the requirements; S04: When the drying requirements are met, the bottommost conveying component rotates in the opposite direction, and the material enters the conveying equipment from the main discharge chute and is transferred to the next stage.

[0022] This invention, through a switching method between circulating drying and direct transfer, not only ensures the drying effect of materials but also meets the requirements of automated production lines for continuity and efficiency. It reduces manual operation costs and equipment debugging time, adapts to intelligent and continuous production scenarios in modern food processing and other industries, and significantly enhances the comprehensive application value of multi-layer circulating dryers.

[0023] As can be seen from the above technical solutions, the present invention has the following advantages: This invention provides a multi-layer circulating dryer and its operating method. By setting up forward and reverse rotating conveying components, a circulating discharge trough, and a main discharge trough, it can achieve internal circulating drying and dried discharge according to process requirements without manual intervention to adjust the position of the lifting components. This solves the problem of process interruption caused by moving the lifting components in the prior art, ensuring the continuity of the drying process and achieving seamless integration with automated production lines. It significantly improves production efficiency, reduces labor costs, and is more suitable for the high-efficiency and intelligent production needs of modern food processing. By setting the conveying components in an even number of layers, on the one hand, the bottom layer of conveying components can extend the drying path during internal circulating drying, thus playing a drying role; on the other hand, when it is necessary to... When transferring materials to the next stage, the conveying path can be shortened, improving conveying efficiency. By setting two air inlets at the bottom layer, the air volume at the bottom layer can be further increased, enhancing the drying effect on the materials at the bottom layer and improving drying efficiency. By setting a combustion component, the air can be heated, further improving drying efficiency. By sharing a drive component, the layout of drive components is reduced, lowering equipment costs. By switching between circulating drying and direct transfer, the drying effect of materials is ensured while meeting the requirements of continuous and efficient automated production lines, reducing manual operation costs and equipment debugging time. It is suitable for intelligent and continuous production scenarios in modern food processing and other industries, significantly enhancing the comprehensive application value of the multi-layer circulating dryer. Attached Figure Description

[0024] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description 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.

[0025] Figure 1 This is a structural diagram of a specific embodiment of the present invention. Figure 1 .

[0026] Figure 2 This is a structural schematic diagram of Embodiment 1 of the present invention. Figure 2 .

[0027] Figure 3 This is a structural schematic diagram of Embodiment 1 of the present invention. Figure 4 .

[0028] Figure 4 This is a wind path diagram of Embodiment 1 of the present invention.

[0029] In the diagram, 1. Circulating fan; 2. Feeding chute; 3. Drive assembly two; 4. Lifting assembly; 5. Material distributor; 6. Circulating discharge chute; 8. Conveying assembly; 9. Main discharge chute; 10. Drive assembly one; 11. Drive assembly three; 12. Air inlet duct; 13. Exhaust fan; 14. Return air duct; 16. Housing; 17. Combustion assembly; 20. Return air inlet; 21. Air inlet; 22. Air guide plate; 23. Second belt drive assembly; 24. First belt drive assembly; 25. Third belt drive assembly. Detailed Implementation

[0030] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0031] Example 1 like Figures 1 to 3 As shown, this embodiment provides a multi-layer circulating dryer, including a housing 16 and a multi-layer conveying assembly 8. A feeding trough 2 is provided on the upper part of the housing 16 for material to enter and dry. A circulating discharge trough 6 and a main discharge trough 9 are respectively provided at the lower ends of the housing 16. The circulating discharge trough 6 and the feeding trough 2 are located at the same end of the housing 16. A lifting assembly 4 is provided between the feeding trough 2 and the circulating discharge trough 6, which can return the material to the feeding trough 2 for circulation. The main discharge trough 9 is used to connect to corresponding conveying equipment. N layers of conveying assemblies 8 are also horizontally arranged inside the housing 16. The conveying directions of adjacent layers of conveying assemblies 8 are opposite. The uppermost conveying assembly 8 is located below the feeding trough 2, and the lowermost conveying assembly 8 can convey material in both forward and reverse directions. When the lowermost conveying assembly 8 conveys material in the forward direction, it can convey the material to the circulating discharge trough 6. When the lowermost conveying assembly 8 conveys material in the reverse direction, it can convey the material to the main discharge trough 9.

[0032] This embodiment achieves automatic switching between two operating conditions of the same drying system: circulating discharge trough 6 and main discharge end are set at the lower part of the housing 16, and the bottom layer conveying component 8 has a forward and reverse switching function. When the bottom layer conveying component 8 runs in the forward direction, the material is sent to the circulating discharge trough 6 and returned to the feeding trough 2 via the lifting component 4, realizing multiple cycles of drying to ensure drying uniformity and finished product quality. When the bottom layer conveying component 8 runs in the reverse direction, the material is directly conveyed to the main discharge end, achieving stable and reliable fixed docking with the downstream conveying equipment without moving the lifting component 4. This avoids manual handling and downtime debugging, ensures continuous operation of the production line, significantly reduces labor costs and debugging time, improves automation level and overall production efficiency, and enhances the adaptability and flexibility of the equipment under different products and process requirements. At the same time, the feeding trough 2 and circulating discharge trough 6 in this embodiment are located at the same end, which can also reduce the movement path of the material during circulation, reduce heat loss, and improve drying efficiency.

[0033] like Figures 1 to 3As shown, in this embodiment, the number of layers of the conveying assembly 8 is N, where N is an even number. This arrangement has two advantages: firstly, during internal circulating drying, the conveying direction of the bottommost conveying assembly 8 is the same as that of the topmost conveying assembly 8, allowing the material to return to the circulating drying process via the lifting assembly 4 after drying. The bottommost conveying assembly 8 extends the drying path and effectively performs its drying function. Secondly, when it needs to be transferred to the next stage, the conveying path can be shortened, improving conveying efficiency. If an odd number of conveying assemblies 8 are used, the bottommost conveying assembly 8 will not perform its drying function during internal circulating drying, resulting in design redundancy relative to the main function of the device. In this embodiment, the conveying assembly 8 has four layers. The conveying components 8 of the first and third layers share a drive component 10. The conveying components 8 of the second layer are connected to a drive component 3. The conveying components 8 of the fourth layer are the lowest layer and are connected to a drive component 3 11. The drive component 3 11 can rotate forward and backward. By sharing the drive component 10, the number of drive components is reduced, thus lowering the cost of the equipment. Specifically, the drive component 1 includes a servo motor, which is located at the top of the housing 16. The output shaft of the servo motor is connected to a reduction gearbox, and the output shaft of the reduction gearbox is connected to a first belt drive assembly 24. The first belt drive assembly 24 is connected to a drive shaft, which is connected to a corresponding... The belt drive assembly is connected to the drive roller of the uppermost conveyor assembly 8, thereby driving the uppermost conveyor assembly 8 to rotate. Simultaneously, the drive shaft is also connected to the corresponding drive shaft of the third-layer conveyor assembly 8 via the second belt drive assembly 23. This drive shaft is connected to the drive roller of the third-layer conveyor assembly 8 via a corresponding belt drive assembly, achieving synchronous and co-directional operation of the first and third-layer conveyor assemblies 8. Drive assembly 23 includes a servo motor, which is located at the top of the housing 16. The motor shaft of the servo motor is connected to a corresponding reduction gearbox. The output shaft of the reduction gearbox is connected to the drive roller of the second-layer conveyor assembly 8 via the third belt drive assembly 25, thereby driving the second-layer conveyor assembly 8. Drive assembly 31 includes... A corresponding servo motor, capable of both forward and reverse rotation, is located at one end of the housing 16. The motor shaft of the servo motor is connected to a corresponding gearbox, and the output shaft of the gearbox is connected to the drive roller of the fourth-layer conveying assembly 8 via a belt drive assembly, thereby driving the fourth-layer conveying assembly 8. In this embodiment, the conveying assembly 8 is a chain plate conveyor, which includes multiple hinged chain plates. The multiple hinged chain plates are connected end to end and surround the drive roller and the driven roller. The drive roller and the driven roller are rotatably mounted on a support inside the housing 16 via bearing seats. A transmission chain is provided at both ends of the chain plate, and the transmission chain meshes with the sprockets at both ends of the drive roller and the driven roller. Holes are evenly provided on the chain plate for ventilation.

[0034] like Figure 1 and Figure 3As shown, in this embodiment, the lifting component 4 adopts a C-type bucket elevator. The lifting component 4 includes a feed inlet and a discharge outlet. The feed inlet is located below the circulating discharge trough, and the discharge outlet is located above the feeding trough 2. By using a C-type bucket elevator, the material transfer path can be greatly shortened and heat loss can be reduced. The C-type bucket elevator is a mature product purchased from the market and is existing technology, so it will not be described in detail in this article.

[0035] like Figure 1 As shown, in order to ensure that the material is evenly spread on the uppermost conveying component 8, in this embodiment, the feeding trough 2 is equipped with a material distributor 5, and the discharge port is located above the material distributor 5. The material distributor 5 is a mature product purchased from the market and is existing technology, so it will not be described in detail in this article.

[0036] To ensure that the material on each layer of conveyor assembly 8 can be dried, such as Figures 1 to 4As shown, in this embodiment, an air inlet duct 12 and a return air duct 14 are provided on the outside of the housing 16. A circulating fan 1 is provided on the air inlet duct 12, and a dehumidifying fan is provided on the upper part of the return air duct 14. The air inlet duct 12 has multiple air inlets 21 along its height direction, and the air inlets 21 are located below the corresponding conveying components 8. The return air duct 14 has multiple return air inlets 20 along its height direction, and the return air inlets 20 are located above the corresponding conveying components 8. A guide plate 22 is provided at the lower end of both the air inlet duct 12 and the return air duct 14. The guide plate 22 is inclined. A combustion component 17 is also provided on the upper part of the air inlet duct 12. The combustion component 17 can be connected to a natural gas source. Specifically, the air inlet duct 12 has an inverted L-shaped structure. Its horizontal part is located on the upper part of the housing 16 and is equipped with a circulating fan 1. Its vertical part is vertically located on one side of the housing 16 and has multiple air inlets 21. The air inlets 21 blow air into the housing 16. Each air inlet 21 is equipped with a corresponding conveying component 8. The air inlet 21 is located between the upper and lower layers of the corresponding conveying component 8 to avoid the lower layer's return chain plate obstructing the airflow. The return air duct 14 is vertically located on one side of the housing 16, opposite to the vertical part of the air inlet duct 12. A dehumidifying fan 13 is installed at the top of the return air duct 14. Multiple return air inlets 20 are arranged along the height of the return air duct 14. The return air inlets 20 are located on the corresponding conveying components 8. The upper part, namely the air inlet 21 and return air outlet 20 corresponding to the same conveying component 8, are located at both ends of the conveying component 8, and the return air outlet 20 is higher than the air inlet 21. The combustion component 17 includes a combustion chamber and a natural gas burner. The combustion chamber is set on the air inlet duct 12 and communicates with the air inlet duct 12. The burner is installed on the side wall of the combustion chamber. The air inlet end of the burner is connected to an external natural gas source through a natural gas pipeline. A manual valve and a solenoid valve are installed in sequence on the pipeline to realize the opening and closing of the natural gas. During operation, the circulating fan 1 is started to draw the air recovered from the box 16 from the upper part of the air inlet duct 12 and pressurize it along the air inlet duct 12 to the vertical part of the air inlet duct 12. Then, through multiple air inlets 21 arranged along the height direction, the air is drawn into the air inlet duct 16. The heated air is sent to the bottom of each layer of conveying components 8, so that the hot air passes through the material on the corresponding conveying components 8 from bottom to top, thereby drying the material. In order to remove moisture in time, the dehumidifying fan 13 at the top of the return air duct 14 is started. The dehumidifying fan 13 draws air from the top of the return air duct 14, so that multiple return air inlets 20 arranged in the height direction of the return air duct 14 generate negative pressure. The hot and humid air above each layer of conveying components 8 is drawn into the return air duct 14 through the corresponding return air inlets 20 and gathers upward. A part of the hot and humid air is directly discharged from the box 16 by the dehumidifying fan 13 to remove moisture and excess heat. In this embodiment, three circulating fans 1, three dehumidifying fans 13 and three combustion components 17 are provided.

[0037] As the material is continuously dried during downward transport, its internal moisture content decreases. Therefore, the material on the bottommost conveyor assembly 8 is difficult to dry further. To improve the drying efficiency of the bottommost material, such as... Figure 3 and Figure 4 As shown, in this embodiment, the lower part of the bottommost conveying component 8 is provided with at least two air inlets 21. In this embodiment, there are two air inlets 21.

[0038] In this embodiment, a control system is also included. Drive component 10, drive component 2, drive component 3, combustion component 17, circulating fan 1, and dehumidifying fan 13 are all electrically connected to the control system.

[0039] Example 2 This embodiment provides a method for operating a multi-layer circulating dryer, using the multi-layer circulating dryer of Embodiment 1, including the following steps: S01: The circulating fan 1 and the dehumidifying fan 13 start, the feeding trough 2 feeds the material, and the multi-layer conveying assembly 8 works together to convey the material from the top layer to the bottom layer; S02: When circulating drying is required, open the lifting component 4 and control the bottom conveying component 8 to rotate in the forward direction. The material enters the lifting component 4 from the circulating discharge trough 6 and returns to the feeding trough 2 for drying again. S03: Circulate S02 until the material's dryness meets the requirements; S04: When the drying requirements are met, the bottommost conveying component 8 rotates in the opposite direction, and the material enters the conveying equipment from the main discharge chute 9 and is transferred to the next stage.

[0040] This invention, through a switching method between circulating drying and direct transfer, not only ensures the drying effect of materials but also meets the requirements of automated production lines for continuity and efficiency. It reduces manual operation costs and equipment debugging time, adapts to intelligent and continuous production scenarios in modern food processing and other industries, and significantly enhances the comprehensive application value of multi-layer circulating dryers.

[0041] In this method, after the material enters the housing 16 from the feeding chute 2, it first falls onto the first-layer conveying assembly 8 located below the feeding chute 2. Driven by the drive assembly 10, the first-layer conveying assembly 8 conveys the material to the other end of the housing 16 in a predetermined direction, while simultaneously drying it through hot air entering through the corresponding air outlet. The material falls from the end of the first layer onto the second-layer conveying assembly 8, and is conveyed and dried in the opposite direction to the first layer under the drive assembly 3. The material then falls sequentially from the end of the second layer onto the third-layer conveying assembly 8, which is driven by the drive assembly 10 and conveys and dries the material in the opposite direction to the second layer. Finally, the material falls sequentially from the end of the third layer onto the fourth-layer conveying assembly 8. Component 8 is driven by drive assembly 3 11 and conveys in the opposite direction to the third layer, causing the material to reciprocate in a serpentine pattern between the four conveying assemblies 8 to complete multiple drying cycles. When the material needs to be dried in a cyclic manner, drive assembly 3 11 is controlled to rotate forward, causing the fourth conveying assembly 8 to run in the direction of conveying the material to the circulating discharge trough 6. The material enters the lifting assembly 4 through the circulating discharge trough 6 and is lifted back to the feeding trough 2 by the lifting assembly 4, falling back onto the first conveying assembly 8. When it is determined that the material drying has reached the preset requirements, the control system stops the cyclic mode, switches the running direction of the fourth conveying assembly 8, and controls drive assembly 3 11 to rotate in reverse, causing the fourth conveying assembly 8 to directly convey the received material to the main discharge trough 9, thus achieving the discharge of the dried material.

[0042] As can be seen from the above specific embodiments, the present invention has the following beneficial effects: 1. By setting up a forward and reverse reversible conveying component 8, a circulating discharge trough 6, and a main discharge trough 9, internal circulating drying and drying discharge can be realized according to process requirements without manual intervention to adjust the position of the lifting component 4. This solves the problem of process interruption caused by moving the lifting component 4 in the existing technology, ensuring the continuity of the drying process and achieving seamless integration with the automated production line. It significantly improves production efficiency, reduces labor costs, and is more suitable for the high-efficiency and intelligent production needs of modern food processing. 2. By setting the conveying components 8 to an even number of layers, on the one hand, the bottom conveying components 8 can extend the drying path during internal circulation drying and play a drying role; on the other hand, when it is necessary to transfer to the next stage, the conveying path can be shortened and the conveying efficiency can be improved. 3. By setting two air inlets 21 at the bottom layer, the air volume at the bottom layer can be further increased, enhancing the drying effect on the material at the bottom layer and improving the drying efficiency; 4. By setting the combustion component 17, air can be heated, further improving drying efficiency; 5. By sharing the drive component 10, the number of drive components can be reduced, thus lowering the cost of the equipment; 6. By switching between circulating drying and direct transfer, the drying effect of materials is guaranteed, while meeting the requirements of automated production lines for continuity and efficiency. This reduces manual operation costs and equipment debugging time, making it suitable for intelligent and continuous production scenarios in modern food processing and other industries, and significantly enhancing the comprehensive application value of the multi-layer circulating dryer.

[0043] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-layer circulating dryer, comprising a housing (16), wherein a feeding trough (2) is provided on the upper part of the housing (16), characterized in that: The lower two ends of the box (16) are respectively provided with a circulating discharge trough (6) and a main discharge trough (9). The circulating discharge trough (6) and the feeding trough (2) are located at the same end of the box (16). A lifting component (4) is provided between the feeding trough (2) and the circulating discharge trough (6). The main discharge trough (9) is used to connect to the corresponding conveying equipment. The box (16) is also horizontally arranged with N layers of conveying components (8). The conveying directions of the two adjacent layers of conveying components (8) are opposite. The uppermost layer of conveying components (8) is located below the feeding trough (2). The lowermost layer of conveying components (8) can convey in both forward and reverse directions. When the lowermost layer of conveying components (8) conveys in the forward direction, it can convey the material to the circulating discharge trough (6). When the lowermost layer of conveying components (8) conveys in the reverse direction, it can convey the material to the main discharge trough (9).

2. The multi-layer circulating dryer as described in claim 1, characterized in that, The lifting component (4) adopts a C-type bucket elevator. The lifting component (4) includes a feed inlet and a discharge outlet. The feed inlet is located below the circulating discharge trough (6), and the discharge outlet is located above the feeding trough (2).

3. The multi-layer circulating dryer as described in claim 2, characterized in that, The feeding trough (2) is equipped with a material distributor (5), and the discharge port is located above the material distributor (5).

4. The multi-layer circulating dryer as described in claim 3, characterized in that, The number of layers of the conveying component (8) is N, where N is an even number.

5. The multi-layer circulating dryer as described in any one of claims 1-4, characterized in that, The outer side of the housing (16) is provided with an air inlet duct (12) and a return air duct (14). A circulating fan (1) is provided on the air inlet duct (12), and a dehumidifying fan (13) is provided on the upper part of the return air duct (14). The air inlet duct (12) is provided with a plurality of air inlets (21) along its height direction. The air inlets (21) are located below the corresponding conveying components (8). The return air duct (14) is provided with a plurality of return air inlets (20) along its height direction. The return air inlets (20) are located above the corresponding conveying components (8).

6. The multi-layer circulating dryer as described in claim 5, characterized in that, The lower part of the bottommost conveying assembly (8) is provided with at least two air inlets (21).

7. The multi-layer circulating dryer as described in claim 6, characterized in that, Both the air inlet duct (12) and the air return duct (14) are provided with air guide plates (22) at their lower ends, and the air guide plates (22) are set at an angle.

8. The multi-layer circulating dryer as described in claim 5, characterized in that, The upper part of the air inlet duct (12) is also provided with a combustion assembly (17), which can be connected to a natural gas source.

9. The multi-layer circulating dryer as described in claim 4, characterized in that, The conveying component (8) has four layers. The conveying component (8) in the first layer and the conveying component (8) in the third layer share a drive component one (10). The conveying component (8) in the second layer is connected to a drive component two (3). The conveying component (8) in the fourth layer is the lowest layer of the conveying component (8). The conveying component (8) in the fourth layer is connected to a drive component three (11). The drive component three (11) can rotate forward and backward.

10. A method for operating a multi-layer circulating dryer, characterized in that, The multi-layer circulating dryer as described in claim 9 includes the following steps: S01: The circulating fan (1) and the dehumidifying fan (13) are started, the feeding trough (2) feeds the material, and the multi-layer conveying assembly (8) works together to transport the material from the top layer to the bottom layer; S02: When circulating drying is required, open the lifting component (4) and control the bottom conveying component (8) to rotate in the forward direction. The material enters the lifting component (4) from the circulating discharge trough (6) and returns to the feeding trough (2) for drying again. S03: Circulate S02 until the material's dryness meets the requirements; S04: When the drying requirements are met, the bottommost conveying component (8) rotates in the opposite direction, and the material enters the conveying equipment from the main discharge chute (9) and is transferred to the next stage.

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