A drying system and drying control method

Abstract

The application provides a drying system and a drying control method, which provide circulating hot air for a drying module through a hot air module, guarantee heat efficiency, and fluidize and convey the material to be dried into a material pipe of the drying module through airflow, realize drying through a high-temperature environment in the drying module, and the material pipe is alternately composed of a first material pipe and a second material pipe with different pipe diameters, which can reduce the material flow rate, increase the residence time of the material in the drying module, guarantee the drying effect, separate water vapor from the dried material through a gas-solid separation module, and periodically discharge the collected material, so that the drying module can continuously convey the dried material to the gas-solid separation module, and realize continuous drying. The drying system and the drying control method provided by the application can realize continuous drying, improve production efficiency, and through the alternately different pipe diameters of the material pipe, the flow rate of fluidized conveying can be effectively reduced, the residence time of the material in the drying module can be increased, and the drying effect can be effectively guaranteed.

Description

Technical Field

[0001] This invention relates to the field of drying technology, and in particular to a drying system and a drying control method. Background Technology

[0002] Wet granulation is a common pharmaceutical process, mainly used to improve the flowability, compressibility, and uniformity of powders to facilitate subsequent operations such as tableting and capsule filling.

[0003] After wet granulation, the granules contain a large amount of moisture or solvent (from binders or wetting agents). In order to make the granules meet the humidity requirements for subsequent processing (such as tableting, capsule filling, etc.), it is necessary to remove this moisture or solvent through drying.

[0004] In existing technologies, to avoid material loss, the drying of powders and granules is generally carried out using intermittent drying methods, such as oven drying and fluidized bed drying, which results in low production efficiency. Summary of the Invention

[0005] Based on this, the purpose of the present invention is to provide a drying system and a drying control method to solve the problem that the drying of powders and granules in the prior art generally adopts an intermittent drying method, which results in low production efficiency.

[0006] This invention provides a drying system, comprising:

[0007] A drying module includes a first housing and a feed pipe fixedly disposed in the first housing. The feed pipe is used to convey fluidized material to be dried. The drying module is used to heat the inner space of the first housing by incoming hot air, thereby heating the feed pipe and promoting the drying of the material in the feed pipe.

[0008] A hot air module is circulatedly connected to the drying module and is used to provide circulating hot air into the first housing of the drying module.

[0009] The gas-solid separation module is connected to the output end of the material pipe and is used to collect the dried material and periodically feed the collected material so that the drying module can continuously supply the dried material to the gas-solid separation module.

[0010] The material tubes are arranged in a spiral shape and include alternating first and second material tubes, wherein the inner diameter of the first material tube is larger than the inner diameter of the second material tube.

[0011] Optionally, the hot air module's main hot air output pipe is further provided with a hot air branch output pipe, which is connected to the input end of the material pipe, and a hopper is also provided on the hot air branch output pipe, so that the material in the hopper is carried into the material pipe by the hot air flow in the hot air branch output pipe.

[0012] Optionally, the inner diameter ratio of the first feed tube to the second feed tube is 1.2:1 to 3:1.

[0013] Optionally, the air inlet and air outlet of the first housing are respectively located at both ends of the spiral extension direction of the material pipe, and the first housing is further provided with a first guide and a second guide, wherein,

[0014] The first guide member is a plate-shaped structure and is blocked between the air inlet and the material pipe. The first guide member is provided with a first window, which is arranged in a circle. In the spiral extension direction of the material pipe, the projection of the first window at least partially overlaps with the projection of the material pipe.

[0015] The second guide is a hood-shaped structure, which is disposed in the spiral inner space of the material tube and covers the air outlet. A second window is provided on the side of the second guide, and at least two second windows are arranged around it. The total area of ​​the second windows is 2 to 4 times the cross-sectional area of ​​the air inlet.

[0016] Optionally, an exhaust temperature sensor is also provided inside the first housing, and the exhaust temperature sensor is located inside the cover space of the second guide member.

[0017] Optionally, the feed tube has an inner and outer double-layer spiral structure, and the annular area formed by the two middle loops of the inner and outer spirals is directly opposite to and matches the first opening.

[0018] Optionally, the spiral shape of the material tube includes at least one of circular, square, and curved shapes, the shape of the first opening is consistent with the spiral shape of the material tube, the tube body is a spiral tube, and the cross-section of the tube body is any one of circular and elliptical shapes.

[0019] Optionally, the hot air module includes a second housing, and an air intake fan, a first filter, a heater, and a second filter sequentially arranged in the second housing along the hot air circulation direction. The air intake fan is connected to the air outlet of the first housing through an air intake pipe. An air intake valve is also provided on the air intake pipe to obtain the loss of circulating hot air from the outside. A first temperature sensor is provided between the heater and the second filter, and a second temperature sensor is provided on the main hot air output pipe, and the second temperature sensor is located upstream of the location of the branch hot air output pipe.

[0020] Optionally, the gas-solid separation module includes a cyclone separator. The gas output end of the cyclone separator is connected to an exhaust fan through an exhaust pipe. A dust collector is installed at the outlet end of the exhaust fan. A flow meter and a negative pressure sensor are also installed in the exhaust pipe in sequence along the exhaust direction. The solid output end of the cyclone separator is connected to a buffer tank. Both the input and output ends of the buffer tank are equipped with storage control valves.

[0021] The present invention also provides a drying control method applied to the above-mentioned drying system, the drying control method comprising:

[0022] Close the hopper;

[0023] The hot air module is started until the temperature of the circulating hot air stabilizes within the preset target temperature range.

[0024] The gas-solid separation module is started until the exhaust flow rate stabilizes within the preset target flow rate range;

[0025] The hopper is opened and material is fed into it to transport the material to the drying module for drying.

[0026] The gas-solid separation module is periodically discharged according to a preset cycle to control the continuous drying process.

[0027] In addition, the exhaust temperature of the drying module is collected, and the heating power of the hot air module is adjusted according to the exhaust temperature. When the exhaust temperature is lower than a preset exhaust temperature threshold, the heating power of the hot air module is increased, and the working power of the gas-solid separation module is adjusted simultaneously.

[0028] The drying system provided by this invention provides circulating hot air to the drying module via a hot air module, ensuring thermal efficiency. The material to be dried is fluidized and conveyed to the feed pipe of the drying module by the airflow. Drying is achieved through the high-temperature environment within the drying module. The feed pipe is composed of alternating first and second feed pipes of different diameters, which reduces the material flow rate and increases the residence time of the material in the drying module, ensuring the drying effect. After drying, the material passes through a gas-solid separation module to separate water vapor from the dried material. The collected material is periodically fed back to the gas-solid separation module, allowing the drying module to continuously supply the dried material to the gas-solid separation module, achieving continuous drying. The drying system provided by this invention uses a fluidized conveying method to transport materials to the drying module for drying, and the periodic feeding of the collected material by the gas-solid separation module enables continuous drying, improving production efficiency. Furthermore, the alternating and differentiated design of the feed pipe diameters effectively reduces the flow rate of the fluidized conveying, increases the residence time of the material in the drying module, and effectively ensures the drying effect. Additionally, a pulsed conveying airflow can be formed within the feed pipe to prevent material accumulation.

[0029] The drying control method provided by this invention can monitor the circulating hot air and exhaust airflow of the system, which facilitates the input of materials for drying only after the system's flow drying system has stabilized, ensuring the reliability of drying. Moreover, the flow drying can achieve continuous drying, which can effectively improve production efficiency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the drying system in an embodiment of the present invention;

[0031] Figure 2 This is a cross-sectional view of the drying module of the drying system in an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the main structure of the feed pipe of the drying system in an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the application structure of the first flow guide component of the drying module in the drying system of the present invention.

[0034] Figure 5 This is a front view of the first flow guide component of the drying module in the drying system of the present invention.

[0035] Figure 6 This is a schematic diagram of the main structure of the hot air module of the drying system in an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the air-solid wind power module of the drying system in an embodiment of the present invention.

[0037] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0038] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0039] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0041] To address the low production efficiency of intermittent drying methods commonly used in existing technologies for drying powders and small particles, this invention provides a drying system. The material to be dried is conveyed via fluidized bed conveying within the feed pipes of a drying module. Drying is achieved through the high-temperature environment of the drying module. The feed pipes are alternately composed of first and second feed pipes of different diameters, which reduces the material flow rate and increases the residence time of the material in the drying module, ensuring effective drying. The dried material is then separated from the water vapor by a gas-solid separation module. The collected material is periodically discharged, allowing the drying module to continuously supply dried material to the gas-solid separation module, achieving continuous drying. The alternating and differentiated pipe diameter design effectively reduces the fluidized bed conveying velocity, increases the residence time of the material in the drying module, and solves the problem of excessively high pipeline conveying speed, thus effectively ensuring the drying effect.

[0042] Specifically, please refer to Figures 1 to 7 The diagram shows the structure of the drying system in this embodiment of the invention. It mainly includes a drying module 100, a hot air module 200, and a gas-solid separation module 300. The hot air module 200 is cyclically connected to the drying module 100 and is used to provide circulating hot air into the first housing 110 of the drying module 100 to create a high-temperature environment required for drying within the drying module 100.

[0043] like Figure 2 As shown, the drying module 100 includes a first housing 110 and a feed pipe 120 fixedly disposed in the first housing 110. The feed pipe 120 is used to transport fluidized material to be dried. The first housing 110 of the drying module 100 has a double-layer structure with insulation material filling the middle to ensure the thermal efficiency of the high-temperature environment inside the first housing 110, so that the heat of the high-temperature environment inside can effectively heat the feed pipe 120, thereby promoting the drying of the material in the feed pipe 120.

[0044] The gas-solid separation module 300 is connected to the output end of the material pipe 120 to collect the dried material and periodically feed the collected material so that the drying module 100 can continuously feed the dried material to the gas-solid separation module 300 to achieve continuous operation.

[0045] To ensure conveying efficiency, this embodiment employs an airflow conveying method. Smaller particles, such as powder, are conveyed in the feed pipe 120 by the airflow. To prevent material deposition in the feed pipe, the flow rate is generally high, which can easily lead to insufficient residence time of the material in the drying module 100, resulting in inadequate drying effect. To solve this problem, in this embodiment, the feed pipe 120 is arranged in a spiral pattern, ensuring the total length of the feed pipe 120, and as... Figure 3 As shown, the feed pipe 120 includes a first feed pipe 121 and a second feed pipe 122 connected alternately. The inner diameter of the first feed pipe 121 is larger than that of the second feed pipe 122. By setting the different pipe diameters, the material being transported can be obstructed, the flow rate of the material can be reduced, the residence time of the material in the feed pipe 120 can be increased, sufficient drying time can be ensured, and drying efficiency can be guaranteed. Moreover, the flow rate of the material in the first feed pipe 121 and the second feed pipe 122 can naturally form a difference. Its flow is a pulsed motion, which can change the relative speed between the material and the air, increase the heat exchange efficiency, and facilitate the material to effectively impact the pipe wall of the feed pipe 120, fully exchange heat with the feed pipe 120, and improve the uniformity and efficiency of drying.

[0046] To avoid the impact of externally introduced low-temperature airflow on drying efficiency, in this embodiment, such as Figure 1 and Figure 6 As shown, the hot air module 200 is equipped with a hot air branch output pipe 211 on the hot air main output pipe 210. The hot air branch output pipe 211 is connected to the input end of the material pipe 120, and a hopper 401 is also provided on the hot air branch output pipe 211. When the hot air module 200 is working, part of the output hot air is supplied to the material pipe 120 through the hot air branch output pipe 211. When the hopper 401 is opened, the material loaded in the hopper 401 can be sucked into the pipe through Bernoulli's principle, and the material in the hopper 401 is carried into the material pipe 120 by the hot air flow in the hot air branch output pipe 211.

[0047] The material-carrying airflow in the material pipe 120 is hot airflow, which can further improve the drying efficiency of the system, reduce the impact of insufficient drying time caused by the fast flow conveying speed, shorten the total length of the material pipe 120, reduce the equipment volume, and reduce hardware costs.

[0048] To ensure the reliability of the effect of pipe diameter differences on conveying speed, the inner diameter ratio of the first material pipe 121 to the second material pipe 122 can optionally be 1.2:1 to 3:1. At the joint of the material pipes, the inner diameter is preferably linearly and gradually transitioned to avoid right-angle structures, allowing the material to pass smoothly through the site and avoid accumulation.

[0049] To ensure that the hot airflow can effectively pass through the feed pipe 120, the air inlet and outlet of the first housing 110 are respectively located at both ends of the spiral extension direction of the feed pipe 120. Figure 2For example, the air inlet is located at the top, the air outlet is located at the bottom, and the spiral extension direction of the material pipe 120 is vertical.

[0050] To facilitate the installation of the circulating hot air exhaust pipe, in this embodiment, the first housing 110 is mounted on the bracket 111, and the bracket 111 forms a certain installation space below the first housing 110 for the installation of the circulating hot air exhaust pipe.

[0051] Since the thermal efficiency provided by the circulating hot air is limited, it is necessary to limit the arrangement density of the material pipes 120 in the first housing 110. In this embodiment, the material pipes 120 adopt a unidirectional spiral arrangement. Correspondingly, in order to further ensure the accuracy of heating, in this embodiment, the first housing 110 is also provided with a first guide 130 and a second guide 140, which can guide the flow direction of the circulating hot air entering the first housing 110, so that the main flow path of the circulating hot air matches the arrangement space of the material pipes 120, reducing heat dissipation, improving effective thermal efficiency, and improving the system thermal utilization rate.

[0052] Specifically, such as Figure 2 , Figure 4 and Figure 5 As shown, the first guide member 130 has a plate-shaped structure and the block is set between the air inlet and the material pipe 120. The first guide member 130 is provided with a first window, which is arranged in a circle. In the spiral extension direction of the material pipe 120, the projection of the first window overlaps with the projection of the material pipe 120 at least partially, so that the incoming hot air can be directly blown onto the material pipe 120.

[0053] The second guide element 140 has a hood-shaped structure and is disposed in the spiral inner space of the material pipe 120, covering the air outlet. A second window is provided on the side of the second guide element 140, with at least two second windows arranged around it. The total area of ​​the second windows is 2 to 4 times the cross-sectional area of ​​the air inlet to ensure smooth exhaust. The second guide element 140, disposed in the spiral inner space of the material pipe 120, ensures that the circulating airflow can fully flow through the external material pipe 120. Covering the air outlet, it guides the exhaust airflow to converge towards the center, reducing the impact of heat with the first housing 110 and minimizing heat loss.

[0054] To facilitate monitoring of the heating efficiency of the circulating hot air supplied to the drying module 100, in this embodiment, as follows: Figure 2As shown, an exhaust temperature sensor 150 is also installed inside the first housing 110. The exhaust temperature sensor 150 is located within the cover space of the second guide member 140, close to the exhaust port, and can effectively monitor the exhaust temperature. By acquiring the exhaust temperature and combining it with data such as the output temperature and output flow rate of the hot air module, the output heat of the circulating hot air after passing through the drying module 100 can be calculated. The output heat corresponds to the heat required for material drying. When the exhaust temperature is lower than the threshold, the corresponding output heat is too high, and the output heat may not meet the requirements for achieving the target drying effect. It is necessary to increase the flow rate or temperature of the circulating hot air to increase the output heat and improve the drying efficiency.

[0055] In this embodiment, the airflow carrying the material is also provided by the hot air module 200. Increasing the flow rate of the circulating hot air also increases the material conveying speed, which is not conducive to ensuring the residence time of the material in the drying module 100. Furthermore, the operating power of the gas-solid separation module 300 needs to be increased simultaneously to ensure the balance between air intake and exhaust in the material pipe. Therefore, increasing the temperature of the circulating hot air is a better choice when increased output heat is required. When the material flow rate can be controlled independently, there are no particular limitations on the choice between increasing the flow rate or increasing the temperature of the circulating hot air; the choice can be made according to the specific circumstances.

[0056] To reduce the impact of the total length of the material pipe 120 on the equipment volume, in this embodiment, as follows: Figure 3 As shown, the feed tube 120 has an inner and outer double-layer spiral structure, and Figure 4 and Figure 5 As shown, the annular area formed by the two middle loops of the inner and outer spirals is directly aligned with the first window, allowing the hot airflow to enter from the gap between the inner and outer spirals. By utilizing the inner and outer structure of the material tube 120, the dispersion of the input hot air can be reduced, increasing the heating efficiency of the input hot air on the material tube 120 and improving the drying efficiency.

[0057] In this embodiment, the spiral shape of the feed tube 120 is circular, which maximizes space utilization. In alternative embodiments, it can also be square, curved, or other shapes. Corresponding to the spiral shape of the feed tube 120, the shape of the first opening is consistent with the spiral shape of the feed tube to ensure that the input hot air can be directed directly at the feed tube 120, thus ensuring thermal efficiency.

[0058] To enhance heat exchange between the material and the feed tube 120, in an optional embodiment, the feed tube 120 is a spiral tube. This increases the inner surface area of ​​the feed tube 120, improves the contact area between the material and the feed tube 120, and enhances heat exchange efficiency. Furthermore, the spiral tube reduces the airflow velocity, further increasing the residence time of the material within the feed tube 120 and ensuring effective drying. Depending on actual needs, the cross-section of the feed tube 120 can be circular or elliptical.

[0059] To achieve the supply of circulating hot air, in this embodiment, as follows: Figure 6 As shown, the hot air module 200 includes a second housing 201, and an intake fan 221, a first filter 222, a heater 223, and a second filter 224 sequentially arranged within the second housing 201 along the hot air circulation direction. The intake fan 221 is connected to the air outlet of the first housing 110 through an intake duct 240. An intake valve 241 is also provided on the intake duct 240 to supplement the loss of circulating hot air from the outside (the main loss is the airflow used for material conveying). The first filter 222 and the second filter 224 are mainly used to filter the supplementary airflow obtained from the outside to prevent foreign objects in the supplementary airflow from contaminating the material.

[0060] A first temperature sensor 231 is installed between the heater 223 and the second filter 224, and a second temperature sensor 232 is installed on the main hot air output duct 210, with the second temperature sensor 232 positioned upstream of the location of the branch hot air output duct 211. The first temperature sensor 231 is used to monitor the operating temperature of the heater 223 to ensure its normal operation. The second temperature sensor 232 detects the temperature of the output hot air and uses it as a temperature reference. Material is only conveyed and drying is performed after the temperature of the output hot air has stabilized, ensuring the reliability of the drying process.

[0061] To achieve gas-solid separation, in this embodiment... Figure 7 As shown, the gas-solid separation module 300 is mainly achieved through a cyclone separator 310. The gas output end of the cyclone separator 310 is connected to the exhaust fan 330 through an exhaust pipe 320. The exhaust fan 330 is equipped with a dust collector 331 at its outlet to prevent fine particles from being discharged into the air with the exhaust airflow and causing pollution.

[0062] The solid output end of the cyclone separator 310 is connected to the buffer tank 340. Both the input and output pipes of the buffer tank 340 are equipped with storage control valves 341. During stable system operation, the material drying rate generally remains stable at a preset value, meaning the deposition rate of solid material in the cyclone separator 310 is generally fixed. Based on this deposition rate, after a certain amount of dried material has settled, the storage control valve 341 on the input pipe of the buffer tank 340 can be opened to discharge the material into the buffer tank 340. Then, the storage control valve 341 on the input pipe of the buffer tank 340 can be closed, and the storage control valve 341 at the output end of the buffer tank 340 can be opened to discharge the material. The alternating opening of the two discharge control valves 341 ensures that the output passage of the solid output end of the cyclone separator 310 remains closed, preventing solid material from being mistakenly transported to the exhaust fan 330 due to the influence of the exhaust airflow, thus avoiding blockage of the exhaust path.

[0063] The exhaust pipe 320 is also equipped with a flow meter 321 and a negative pressure sensor 322 arranged sequentially along the exhaust direction. These can be used to monitor the exhaust flow rate and exhaust pressure so that the material can be conveyed only after the exhaust flow rate and exhaust pressure have stabilized, thus ensuring the operational stability of the system when it is put into operation for drying.

[0064] This application also provides a drying control method applied to the above-mentioned drying system, the drying control method comprising:

[0065] Enclosed hopper;

[0066] Start the hot air module until the temperature of the circulating hot air stabilizes within the preset target temperature range;

[0067] Start the gas-solid separation module until the exhaust flow rate stabilizes within the preset target flow rate range;

[0068] Open the hopper and feed material into it to transport the material to the drying module for drying;

[0069] The gas-solid separation module discharges material periodically according to a preset cycle to control the continuous drying process.

[0070] In addition, the exhaust temperature of the drying module is collected, and the heating power of the hot air module is adjusted according to the exhaust temperature. When the exhaust temperature is lower than the preset exhaust temperature threshold, the heating power of the hot air module is increased, and the working power of the gas-solid separation module is adjusted simultaneously.

[0071] The drying control method of this application can increase the continuous operability of continuous drying by controlling the discharge. In addition, before the material is conveyed and the drying is performed, the circulating hot air and exhaust air flow are monitored. The material is conveyed and the drying is performed only after the circulating hot air and exhaust air flow are stable. This can ensure the stability and reliability of the drying process.

[0072] The drying system and drying control method provided by this invention can effectively realize the cyclic drying of small particulate materials such as powders. The structure is simple and effective, and it is easy to control costs. It fills the technical gap in continuous powder drying equipment and provides convenience for powder drying production.

[0073] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] The above-described embodiments are merely illustrative of several specific implementations of the present invention, and while the descriptions are detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A drying system, characterized in that, include: A drying module includes a first housing and a feed pipe fixedly disposed in the first housing. The feed pipe is used to convey fluidized material to be dried. The drying module is used to heat the inner space of the first housing by incoming hot air, thereby heating the feed pipe and promoting the drying of the material in the feed pipe. A hot air module is circulatedly connected to the drying module and is used to provide circulating hot air into the first housing of the drying module. The gas-solid separation module is connected to the output end of the material pipe and is used to collect the dried material and periodically feed the collected material so that the drying module can continuously supply the dried material to the gas-solid separation module. The material tube is arranged in a spiral shape and includes an alternately connected first material tube and a second material tube, wherein the inner diameter of the first material tube is larger than the inner diameter of the second material tube. The air inlet and air outlet of the first housing are respectively located at both ends of the spiral extension direction of the material tube. The first housing also contains a first guide element and a second guide element. The first guide member is a plate-shaped structure and is blocked between the air inlet and the material pipe. The first guide member is provided with a first window, which is arranged in a circle. In the spiral extension direction of the material pipe, the projection of the first window at least partially overlaps with the projection of the material pipe. The second guide is a hood-shaped structure, which is disposed in the spiral inner circle space of the material tube and covers the air outlet. A second window is provided on the side of the second guide, and at least two second windows are arranged around it. The total area of ​​the second windows is 2 to 4 times the cross-sectional area of ​​the air inlet. The material tube has an inner and outer double-layer spiral structure, and the annular area formed by the two middle loops of the inner and outer spirals is directly opposite to the first opening. The hot air module's main hot air output pipe is also equipped with a hot air branch output pipe, which is connected to the input end of the material pipe. The hot air branch output pipe is also equipped with a hopper, so that the material in the hopper can be carried into the material pipe by the hot air flow in the hot air branch output pipe.

2. The drying system according to claim 1, characterized in that, The ratio of the inner diameter of the first feed tube to that of the second feed tube is 1.2:1 to 3:

1.

3. The drying system according to claim 1, characterized in that, An exhaust temperature sensor is also provided inside the first housing, and the exhaust temperature sensor is located inside the cover space of the second guide member.

4. The drying system according to claim 1, characterized in that, The spiral shape of the material tube includes at least one of circular, square, and curved shapes. The shape of the first opening is consistent with the spiral shape of the material tube. The tube body is a spiral tube, and the cross-section of the tube body is any one of circular and elliptical shapes.

5. The drying system according to claim 1, characterized in that, The hot air module includes a second housing, and an air intake fan, a first filter, a heater, and a second filter arranged sequentially within the second housing along the hot air circulation direction. The air intake fan is connected to the air outlet of the first housing through an air intake pipe. An air intake valve is also provided on the air intake pipe to obtain external replenishment for the loss of circulating hot air. A first temperature sensor is provided between the heater and the second filter, and a second temperature sensor is provided on the main hot air output pipe, with the second temperature sensor located upstream of the location of the branch hot air output pipe.

6. The drying system according to claim 1, characterized in that, The gas-solid separation module includes a cyclone separator. The gas output end of the cyclone separator is connected to an exhaust fan through an exhaust pipe. A dust collector is installed at the outlet end of the exhaust fan. A flow meter and a negative pressure sensor are also installed in the exhaust pipe in sequence along the exhaust direction. The solid output end of the cyclone separator is connected to a buffer tank. Both the input and output ends of the buffer tank are equipped with storage control valves.

7. A drying control method, applied to the drying system according to any one of claims 1 to 6, characterized in that, The drying control method includes: Close the hopper; The hot air module is started until the temperature of the circulating hot air stabilizes within the preset target temperature range. The gas-solid separation module is started until the exhaust flow rate stabilizes within the preset target flow rate range; The hopper is opened and material is fed into it to transport the material to the drying module for drying. The gas-solid separation module is periodically discharged according to a preset cycle to control the continuous drying process. In addition, the exhaust temperature of the drying module is collected, and the heating power of the hot air module is adjusted according to the exhaust temperature. When the exhaust temperature is lower than a preset exhaust temperature threshold, the heating power of the hot air module is increased, and the working power of the gas-solid separation module is adjusted simultaneously.

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