A modular cross-flow belt dryer and its drying method

Abstract

This invention discloses a modular through-flow belt dryer and its drying method. The dryer includes at least two drying chamber modules connected in series. Each drying chamber module has an upper air-blowing chamber and a lower air-blowing chamber located on both sides of a mesh belt conveyor system, and is equipped with a heating circulation unit and an airflow switching mechanism. The airflow switching mechanism independently configures the flow direction of hot air in each drying chamber module, selectively causing the hot air to form an upward or downward flow path, thereby establishing an independently configurable airflow circulation within each drying chamber module. Removable isolation components are provided between adjacent drying chamber modules. By installing or removing these components, and in conjunction with the programmed control of the airflow switching mechanism, various composite drying methods, such as "process segmentation" or "functional expansion," can be quickly and conveniently combined on the same production line. This solution achieves flexible arrangement of the process flow, greatly improving the process flexibility of the equipment.

Description

Technical Field

[0001] This application relates to the field of drying equipment technology, and in particular to a modular cross-flow belt dryer and its drying method applicable to the food, agriculture, pharmaceutical and chemical industries. Background Technology

[0002] Belt dryers are widely used material drying equipment in industrial production, especially in the food, chemical, and agricultural product industries. Traditional belt dryers typically adopt an integrated, one-piece box structure, and their internal airflow organization, such as top blowing, bottom blowing, or cross-flow, is fixed once the design and manufacturing are completed. The drawback of this design is that its drying process is singular and fixed, only adaptable to specific types or conditions of materials. When production needs change and materials with different characteristics (such as moisture content, specific gravity, and heat sensitivity) need to be processed, its adaptability is extremely poor. It cannot achieve segmented and precise control of the different stages of the drying process, such as "fixing," "dehydration," "shaping," and "aroma enhancement," thus limiting its application scope.

[0003] To address the aforementioned issues, existing technologies have proposed a solution that combines different drying modes. For example, Chinese patent application publication CN102141340A discloses a through-flow belt dryer, which divides the drying chamber into two fixed, series-connected functional sections: an "upward-blowing drying chamber" and a "downward-blowing drying chamber." By combining chambers with two different blowing modes, a combined drying process of first upward-blowing and then downward-blowing (or vice versa) is achieved, which enhances the richness of the process to some extent. Chinese patent application publication CN211782592U discloses a novel through-flow belt dryer that also adopts a similar design concept, explicitly dividing the drying shell into two parts: an "upward-blowing drying shell" and a "downward-blowing drying shell."

[0004] While these solutions recognize the importance of combining different blowing modes, they essentially solidify two functions within two physical structures, resulting in a rigid drying process. For example, it's impossible to connect two "upward blowing" units or two "downward blowing" units in series to extend the time of a specific process, nor can a complex, staggered "upward blowing-downward blowing-upward blowing" process be implemented on a single production line. More importantly, when it's necessary to adjust the process sequence or expand a process area, the only solution remains large-scale shutdown, physical disassembly, and reassembly of the equipment. This fails to fundamentally address the issues of flexibility and responsiveness in process adjustments. This approach is time-consuming and labor-intensive, severely impacting production efficiency and failing to address the fundamental challenge of flexible process configuration.

[0005] Therefore, there is an urgent need in this field to provide a new type of dryer that is not only structurally easy to expand, but more importantly, it should allow for the free arrangement and reconstruction of the process flow of the entire drying line in a fast and convenient manner. It should be able to achieve "process segmentation" in different modes and "functional area expansion" in the same mode, thereby completely eliminating the dependence of the process flow on the physical structure of the equipment and meeting flexible and ever-changing production needs. Summary of the Invention

[0006] The purpose of this application is to provide a modular cross-flow belt dryer and its drying method, which solves the technical problems of existing dryers having fixed process flows, difficult adjustments, and inability to flexibly adapt to changing production needs.

[0007] This application provides a drying method for a modular through-flow belt dryer. The dryer includes at least two drying chamber modules connected in series. Each drying chamber module has an upper blowing chamber and a lower blowing chamber located on both sides of a mesh belt conveyor system, and is equipped with a heating circulation unit and an airflow switching mechanism. In each drying chamber module, the flow direction of hot air is independently configured by the airflow switching mechanism. Hot air can selectively flow from the upper blowing chamber through the material layer on the mesh belt conveyor system into the lower blowing chamber to form an upward through-flow path, or from the lower blowing chamber through the material layer on the mesh belt conveyor system into the upper blowing chamber to form a downward through-flow path. This establishes an independently configurable airflow circulation within each drying chamber module. This application, through the combination of "standard functional modules + airflow switching mechanism," makes the entire production line a freely combinable platform. The flow direction of each module is no longer fixed but independently configured by the airflow switching mechanism, laying a fundamental structural foundation for flexible process arrangement.

[0008] Furthermore, in the upward blowing flow path, hot air is introduced into the upward blowing chamber through the air inlet channel, passes downward through the material layer on the mesh belt conveyor system into the downward blowing chamber, and then returns to the heating circulation unit through the return air channel. At the same time, some of the humid airflow is discharged from the side of the downward blowing chamber through the dehumidification channel. In the downward blowing flow path, hot air is introduced into the downward blowing chamber through the air inlet channel, passes upward through the material layer on the mesh belt conveyor system into the upward blowing chamber, and then returns to the heating circulation unit through the return air channel. At the same time, some of the humid airflow is discharged from the side of the upward blowing chamber through the dehumidification channel.

[0009] Furthermore, the chambers of at least two adjacent drying chamber modules are isolated from each other, and the at least two drying chamber modules are configured with different flow paths, so that the material undergoes flow drying in different directions along the conveying direction in sequence, forming process segment sections.

[0010] Furthermore, the upper air blowing chambers of at least two adjacent drying chamber modules are interconnected, and the corresponding lower air blowing chambers are interconnected. The at least two drying chamber modules are configured with the same flow path to form a functional extension section.

[0011] Furthermore, by isolating or connecting the chambers between each drying chamber module, and by independently configuring the flow path of each module, the entire drying path can selectively include any combination of at least one process segment and / or at least one functional extension segment.

[0012] This application also provides a modular through-flow belt dryer for implementing the above-described drying method, comprising a drying chamber and a mesh belt conveyor system running through the drying chamber. The drying chamber consists of at least two drying chamber modules connected in series. Each drying chamber module includes a drying chamber unit and a heating circulation unit. The drying chamber unit has an upper air blowing chamber and a lower air blowing chamber located on both sides of the mesh belt conveyor system. The heating circulation unit is connected to both the upper and lower air blowing chambers. Each drying chamber module also includes an airflow switching mechanism for selectively allowing hot air from the heating circulation unit to pass through the mesh belt conveyor system from above or below. This application, through the design of "heating circulation unit connected to both the upper and lower air blowing chambers + airflow switching mechanism," allows the same standard module to select different flow directions, overcoming the fundamental defects of traditional equipment where hot air supply only connects to one side of the air chamber and the flow direction is fixed in the physical structure.

[0013] Furthermore, a detachable isolator is provided between adjacent drying chamber modules. When installed, the detachable isolator isolates the respective chambers of adjacent drying chamber modules; when removed, it connects the corresponding upper air blowing chambers and corresponding lower air blowing chambers of adjacent drying chamber modules. The installation or removal of the detachable isolator allows for flexible switching between isolation and connection between the chambers of adjacent modules, providing a physical basis for both process segmentation and functional expansion configurations.

[0014] Furthermore, the heating circulation unit includes a makeup air chamber, a circulating fan, a heating buffer chamber, and a heat exchanger; the makeup air chamber is located on the inlet side of the circulating fan, and the heating buffer chamber is located on the inlet side of the heat exchanger; the outlet of the heat exchanger is connected to the air inlet channel, and the makeup air chamber is provided with a makeup air inlet and is connected to the return air channel. Through the connection design between the makeup air chamber and the return air channel, pre-mixing of return air and fresh air is achieved, reducing airflow pulsation; the heating buffer chamber, by extending the airflow path, ensures that the air is sufficiently stabilized before the heat exchanger inlet, improving heat exchange efficiency.

[0015] Furthermore, the heating circulation unit is connected to the upper and lower air-blowing chambers via an air inlet channel and a return air channel. The drying chamber unit is also provided with a dehumidification channel connected to the upper and lower air-blowing chambers. The airflow switching mechanism is a valve group, which includes an upper air inlet valve, a lower air inlet valve, an upper air return valve, a lower air return valve, an upper dehumidification valve, and a lower dehumidification valve disposed at the connection points between the air inlet channel, the return air channel, and the dehumidification channel and the upper and lower air-blowing chambers. When the drying chamber module is in the upward blowing flow mode, the lower air inlet valve, the upper air return valve, and the upper dehumidification valve are closed, and the upper air inlet valve, the lower air return valve, and the lower dehumidification valve are open. When the drying chamber module is in the downward blowing flow mode, the upper air inlet valve, the lower air return valve, and the lower dehumidification valve are closed, and the lower air inlet valve, the upper air return valve, and the upper dehumidification valve are open.

[0016] Furthermore, it also includes a control system, which is used to electrically connect to and control the airflow switching mechanism and the heating circulation unit of each of the drying chamber modules, and to receive signals from temperature and humidity sensors in the upper and lower air blowing chambers to execute linkage control according to preset instructions. Through the coordinated control of the airflow switching mechanism and the heating circulation unit by the control system, different drying modes can be quickly switched without stopping the machine, ensuring that the temperature and humidity parameters of each process section are accurately matched to changes in material characteristics.

[0017] The technical advantages of this application are as follows: 1. This application sets up an airflow switching mechanism in each drying chamber module and connects it with a heating circulation unit that is connected to both the upper and lower air blowing chambers. This allows the same standard module to select either an upper or lower air blowing path, and the flow direction is no longer fixed in the physical structure. Thus, the flow direction can be independently configured without changing the equipment shell, overcoming the technical limitation that the flow direction in traditional equipment is determined by the shell structure and cannot be dynamically adjusted.

[0018] 2. This application, through the independent configuration of the flow direction of each drying chamber module and the isolation or connection of the chambers, can flexibly combine process segment sections and functional expansion sections on the same equipment, so that the process arrangement of the entire drying path is no longer limited by the physical structure of the equipment, and can adapt to the drying process requirements of different materials without disassembling and reassembling the equipment.

[0019] 3. This application achieves the switching between isolation and communication states of adjacent module chambers by installing or removing detachable isolation components, providing a convenient physical means for both process segmentation and functional expansion configurations, and simplifying the operation process of modular structure adjustment.

[0020] 4. This application achieves online switching of the flow direction of each module and real-time adjustment of process parameters through the linkage control of the airflow switching mechanism and the heating circulation unit by the control system, so as to respond to the changes in process requirements of materials at different drying stages without stopping the machine. Attached Figure Description

[0021] Figure 1 This is an isometric schematic diagram of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 2 This is a side view of the installation telescopic transition cover of a modular through-flow belt dryer provided in an embodiment of this application; Figure 3 This is an axial view of the return air direction of the drying chamber module of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 4 This is an axial side view of the air inlet direction of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 5 This is an axial side view of the dehumidification direction of the drying chamber module of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 6 This is a cross-sectional view of a drying chamber unit of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 7 This is a partially enlarged cross-sectional view of a drying chamber unit of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 8 This is a cross-sectional view of the drying chamber module of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 9 This is a cross-sectional view of the heating circulation unit of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 10 This is a schematic diagram of the control system of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 11 This is a side view (a) of the top-blowing cross-flow path of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 12 This is a schematic diagram (b) of the top-blowing cross-flow path of a modular cross-flow belt dryer provided in an embodiment of this application; Figure 13 This is a side view (a) illustrating the downflow path of a modular crossflow belt dryer provided in this application embodiment; Figure 14 This is a schematic diagram (b) of the downflow path of a modular crossflow belt dryer provided in this application embodiment; In the picture: 1. Drying chamber; 2. Mesh belt conveyor system; 10. Drying chamber module; 11. Drying chamber unit; 111. Upper blowing chamber; 112. Lower blowing chamber; 113. Flange; 114. Removable isolation component; 115. Partition mounting hole; 116. Telescopic transition cover; 117. Air distribution plate; 118. Air distribution support plate; 1181. Mounting hole; 119. Inspection port; 12. Heating circulation unit; 121. Makeup air chamber; 122. Circulating fan; 123. Heating buffer chamber; 124. Heat exchanger; 125. Makeup air inlet; 13. Air intake duct; 14. Air return duct; 15. Dehumidification duct; 16. Airflow switching mechanism; 161. Upper air inlet valve; 162. Lower air inlet valve; 163. Upper return air valve; 164. Lower return air valve; 165. Upper exhaust valve; 166. Lower exhaust valve; 17. Control system. Detailed Implementation

[0022] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0023] Example 1 Reference Figure 1 and Figure 3-5 This application provides a modular through-flow belt dryer, including a drying chamber 1 arranged along the material conveying direction, and a mesh belt conveyor system 2 that runs through the drying chamber 1. The drying chamber 1 is composed of multiple drying chamber modules 10 connected in series.

[0024] Each drying chamber module 10 includes a drying chamber unit 11 and a heating circulation unit 12. The drying chamber unit 11 has an upper air blowing chamber 111 and a lower air blowing chamber 112 located on both sides of the mesh belt conveyor system 2. The heating circulation unit 12 is connected to both the upper air blowing chamber 111 and the lower air blowing chamber 112. Each drying chamber module 10 also includes an airflow switching mechanism 16 for selectively allowing hot air from the heating circulation unit 12 to pass through the mesh belt conveyor system 2 from above or below.

[0025] In this embodiment, the airflow switching mechanism 16 is a valve group (other airflow switching mechanisms such as rotatable air duct switching plate, movable guide baffle, etc. can also be used), and the heating circulation unit 12 is a circulating heating structure (other forms of hot air supply such as external hot air source access interface or electric heating air supply device can also be used).

[0026] Multiple drying chamber modules 10 are connected in series via flanges 113. A detachable isolation component 114 is provided between adjacent drying chamber modules 10 (other forms such as insert-type sealing doors, folding curtains, or electromagnetic adsorption partitions can also be used, as long as they can achieve the switching of isolation or connectivity between the chambers of adjacent drying chamber modules 10). During installation, the detachable isolation component 114 isolates the respective chambers of adjacent drying chamber modules 10; during removal, it connects the corresponding upper air blowing chambers 111 and the corresponding lower air blowing chambers 112 of adjacent drying chamber modules 10.

[0027] Through the above scheme, each drying chamber module 10 can be independently configured with a flow direction via the airflow switching mechanism 16. Combined with the installation or removal of the detachable isolation component 114, this allows for flexible switching between process segmentation sections and functional expansion sections. Even without the detachable isolation component 114, each drying chamber module 10 can still be independently configured with a flow direction via its respective airflow switching mechanism 16.

[0028] Reference Figure 8-9 In one specific embodiment, the heating circulation unit 12 includes a makeup air chamber 121, a circulating fan 122, a heating buffer chamber 123, and a heat exchanger 124. The makeup air chamber 121 is located on the inlet side of the circulating fan 122 and is used to introduce outside air before the airflow enters the circulating fan 122. The heating buffer chamber 123 is located on the inlet side of the heat exchanger 124 and is used to premix and buffer the air before it enters the heat exchanger 124. The outlet of the heat exchanger 124 is connected to the air inlet channel 13, ensuring that the heated air directly enters the drying area. The makeup air chamber 121 is provided with a makeup air inlet 125 and is connected to the return air channel 14, allowing the return air and makeup air to mix before the circulating fan.

[0029] Specifically, when the circulating fan 122 is running, the humid and hot air in the return air duct 14 is drawn into the make-up air chamber 121 and mixed with the outside air entering through the make-up air inlet 125. The mixed airflow enters the heating buffer chamber 123, where the flow velocity is reduced and the airflow is evenly distributed under the buffering effect, and then enters the heat exchanger 124 for heating. The heated air is then transported to the drying chamber unit 11 through the air inlet duct 13. This structure, through the connection design between the make-up air chamber 121 and the return air duct 14, achieves pre-mixing of return air and fresh air, reducing airflow pulsation. The heating buffer chamber 123, by extending the airflow path, ensures that the air is sufficiently stabilized before the inlet of the heat exchanger 124, improving heat exchange efficiency. The outlet of the heat exchanger 124 is directly connected to the air inlet duct 13 to avoid heat loss.

[0030] Reference Figure 3-5In one specific embodiment, the heating circulation unit 12 is connected to the upper blowing chamber 111 and the lower blowing chamber 112 via the air inlet channel 13 and the air return channel 14. The drying chamber unit 11 is also provided with a dehumidification channel 15 connected to the upper blowing chamber 111 and the lower blowing chamber 112. The airflow switching mechanism 16 is a valve group, including an upper air inlet valve 161, a lower air inlet valve 162, an upper air return valve 163, a lower air return valve 164, an upper dehumidification valve 165, and a lower dehumidification valve 166. These valves are respectively located at the connections between the air inlet channel 13, the air return channel 14, and the dehumidification channel 15 and the upper blowing chamber 111 and the lower blowing chamber 112.

[0031] For example, the upper air inlet valve 161 and the lower air inlet valve 162 are installed at the connection between the air inlet channel 13 and the drying chamber unit 11; the upper return air valve 163 and the lower return air valve 164 are installed at the connection between the return air channel 14 and the drying chamber unit 11; and the upper exhaust valve 165 and the lower exhaust valve 166 are installed at the connection between the exhaust channel 15 and the drying chamber unit 11. The valves can be electric or pneumatic butterfly valves, connected to the control system 17 via actuators.

[0032] Reference Figure 11-12 When the drying chamber module 10 is in the upward blowing through-flow mode, the lower inlet valve 162, the upper return air valve 163, and the upper exhaust valve 165 are closed, while the upper inlet valve 161, the lower return air valve 164, and the lower exhaust valve 166 are open. Hot air enters the upper blowing chamber 111 from the air inlet channel 13 via the upper inlet valve 161, passes downward through the material layer on the mesh belt conveyor system 2 into the lower blowing chamber 112, and then returns to the return air channel 14 via the lower return air valve 164. At the same time, some of the humid airflow is discharged from the lower blowing chamber 112 side via the lower exhaust valve 166 from the exhaust channel 15.

[0033] Reference Figure 13-14 When the drying chamber module 10 is in the down-blowing flow mode, the upper air inlet valve 161, the lower air return valve 164, and the lower exhaust valve 166 are closed, while the lower air inlet valve 162, the upper air return valve 163, and the upper exhaust valve 165 are open. Hot air enters the lower blowing chamber 112 from the air inlet channel 13 via the lower air inlet valve 162, passes upward through the material layer on the mesh belt conveyor system 2 into the upper blowing chamber 111, and then returns to the return air channel 14 via the upper air return valve 163. At the same time, some of the humid airflow is discharged from the upper blowing chamber 111 side via the upper exhaust valve 165 from the exhaust channel 15.

[0034] Reference Figure 6-7In one specific embodiment, both the upper air-blowing chamber 111 and the lower air-blowing chamber 112 are provided with air-distributing support plates 118, which have several mounting holes 1181. The air-distributing perforated plate 117 is a standard-sized unitized perforated plate with a stepped boss structure on its edge, used to embed into the mounting holes 1181 of the air-distributing support plate 118, and is fixedly connected using a quick-fastening method. During installation, the stepped boss of the air-distributing perforated plate 117 is aligned with the mounting holes 1181 of the air-distributing support plate 118, and vertically pressed down to fully embed the boss into the mounting holes 1181. The locking mechanism is then rotated to complete the fixation. An inspection port 119 is provided on one side of the drying chamber unit 11. The air-distributing perforated plate 117 is installed or removed through the inspection port 119, allowing operators to disassemble and replace the perforated plate without disassembling the drying chamber module 10.

[0035] Reference Figure 5 The drying chamber modules 10 are isolated or connected by detachable separators 114. This application further proposes that both sides of the upper air chamber 111 and lower air chamber 112 in the drying chamber unit 11 are provided with partition mounting holes 115. The partition mounting holes 115 adopt a stepped recessed platform structure, which cooperates with the stepped platform of the detachable separator 114 to form a labyrinth seal, and is fixedly connected by a quick-fastening method. The partition mounting holes 115 are machined into stepped groove structures on both sides of the air chamber, and the edges of the detachable separator 114 are correspondingly machined into stepped bosses, with the boss size and groove forming a clearance fit. During installation, pushing the partition into place forms a labyrinth seal with multiple zigzag contact surfaces. During disassembly, loosening the fasteners allows the partition to be pulled out. The stepped structure ensures positioning accuracy during repeated installation.

[0036] Reference Figure 2 In one specific embodiment, a telescopic transition cover 116 is provided at the flange 113 mating joint between multiple drying chamber modules 10 to provide an airtight seal at the flange 113 mating joint and to compensate for the relative displacement of the drying chamber modules 10 caused by thermal expansion and contraction or uneven ground conditions. The telescopic transition cover 116 is made of a flexible material (such as high-temperature resistant silicone or Teflon material), and its two ends are fixedly connected to the edge of the flange 113 by clamps. The corrugated structure allows axial expansion and contraction to compensate for the amount of displacement.

[0037] Reference Figure 10 In one specific embodiment, the modular cross-flow belt dryer also includes a control system 17. The control system 17 is used to electrically connect to and control the airflow switching mechanism 16 (such as a damper actuator) and the heating circulation unit 12 (such as a circulating fan 122, heat exchanger 124, etc.) of each drying chamber module 10, and to receive signals from temperature and humidity sensors in the upper air chamber 111 and the lower air chamber 112 to perform linkage control according to preset instructions.

[0038] The control system 17 consists of a programmable logic controller (PLC), distributed I / O modules, a human-machine interface (HMI), and a communication network. The HMI is equipped with a process recipe database, which includes preset instruction control programs for top-blowing, bottom-blowing, and mixing modes. During operation, the PLC adjusts the damper opening, fan speed, and heating power in real time based on feedback signals from temperature and humidity sensors, maintaining stable process parameters for each module through a closed-loop control algorithm.

[0039] Example 2 This embodiment provides a drying method based on the modular cross-flow belt dryer described in Embodiment 1. The dryer includes at least two drying chamber modules 10 connected in series, and each drying chamber module 10 is provided with a heating circulation unit 12 and an airflow switching mechanism 16.

[0040] The airflow switching mechanism 16 independently configures the flow direction of hot air in each drying chamber module 10, selectively allowing hot air to pass through the material layer on the mesh belt conveyor system 2 from the upper blowing chamber 111 to enter the lower blowing chamber 112 to form an upward blowing flow path, or to pass through the material layer on the mesh belt conveyor system 2 from the lower blowing chamber 112 to enter the upper blowing chamber 111 to form a downward blowing flow path, thereby establishing an airflow circulation in each drying chamber module 10 with independently configurable flow direction.

[0041] Reference Figure 11-12 In the upward blowing flow path, hot air is introduced into the upward blowing chamber 111 through the air inlet channel 13, passes down through the material layer on the mesh belt conveyor system 2 and enters the downward blowing chamber 112, and then returns to the heating circulation unit 12 through the return air channel 14. At the same time, some of the humid airflow is discharged from the side of the downward blowing chamber 112 through the dehumidification channel 15.

[0042] Reference Figure 13-14 In the downward blowing flow path, hot air is introduced into the downward blowing chamber 112 through the air inlet channel 13, passes upward through the material layer on the mesh belt conveyor system 2 and enters the upper blowing chamber 111, and then returns to the heating circulation unit 12 through the return air channel 14. At the same time, some of the humid airflow is discharged from the side of the upper blowing chamber 111 through the dehumidification channel 15.

[0043] Since each drying chamber module 10 is equipped with an independent airflow switching mechanism 16, the flow direction of each drying chamber module 10 can be selected independently. That is, adjacent modules can be configured with different flow paths (such as one blowing upwards and the other blowing downwards), or they can be configured with the same flow path, thus providing a methodological basis for subsequent process segmentation and functional expansion.

[0044] Example 3 This embodiment, based on Embodiments 1 and 2, further illustrates how to combine two different processing sections by configuring the flow direction in conjunction with the isolation / connection of chambers. It aims to solve the fundamental application problem in existing drying technologies: the process flow is too simple and cannot be dynamically adjusted according to material characteristics and drying stage requirements.

[0045] (a) Process segmentation At least two adjacent drying chamber modules 10 have their respective chambers isolated from each other (e.g., by installing a removable separator 114 to achieve chamber isolation). At least two drying chamber modules 10 are configured with different flow paths, so that the material undergoes flow drying in different directions along the conveying direction in sequence, forming process segment sections.

[0046] In this section, because the chambers of adjacent modules are isolated, each module can independently set different flow directions and process parameters (temperature, air velocity, etc.), thereby applying differentiated airflow treatment to the material at different stages. For example, the front section uses an upward blowing mode to quickly shape the material surface, while the rear section uses a downward blowing mode to efficiently dehydrate the material using a strong penetrating airflow.

[0047] (ii) Functional expansion section At least two adjacent drying chamber modules 10 have corresponding upper air chambers 111 that are interconnected and corresponding lower air chambers 112 that are interconnected (e.g., by removing the removable separator 114 to make the chambers interconnected), and at least two drying chamber modules 10 are configured with the same flow path to form a functional extension section.

[0048] In this section, because the chambers of adjacent modules are connected, an extended drying area is formed, which expands the action time and length of the drying area in the same flow direction. For example, configuring two adjacent modules in top-blowing mode creates an extended top-blowing drying area, suitable for process stages requiring longer drying times.

[0049] (III) Combination and Arrangement By isolating or connecting the chambers between the drying chamber modules 10, and by independently configuring the flow paths of each module, the entire drying path can selectively include any combination of at least one process segment and / or at least one functional extension segment. For example, a functional extension segment (preheating) can be used in the front section of the drying path, a process segment segment (gradient drying) can be used in the middle section, and a functional extension segment (cooling and shaping) can be used again in the rear section; alternatively, all sections can be process segments, with different flow directions and process parameters configured independently for each module, to achieve precise temperature profile control.

[0050] Example 4 For example, in the compound drying process of wolfberry, a drying line consisting of five drying chamber modules connected in series is used to carry out multi-stage fine drying of wolfberry. Step 1: Configure the high-efficiency and rapid dehydration section (modules 1-2).

[0051] First, the operator removes the detachable separator 114 between drying chamber module 10 and drying chamber module 10, connecting the chambers of the two modules. This configuration forms a "functional expansion section." Then, through the control system 17, drying chamber modules 10 and 10 are uniformly set to "downflow mode," and the process parameters are set: temperature 70℃ and high air velocity. This section is used for efficient and rapid dehydration of high-moisture goji berries.

[0052] Step 2: Configure the steady-speed drying and sugar conversion sections (modules 3-4).

[0053] The operator ensures that the removable separators 114 between drying chamber modules 10 (2 and 3, and 3 and 4) are installed, forming a "process segmentation zone". Through the control system 17, both drying chamber modules 10 (3 and 4) are set to "upflow mode" with independent, decreasing temperature parameters: 65°C for module 3 and 60°C for module 4, with a medium airflow rate. This zone is used for steady-speed drying of the material and promoting internal sugar conversion.

[0054] Step 3: Configure the softening and aroma enhancement and moisture balance sections (Module 5).

[0055] The operator ensures that the removable separator 114 between drying chamber modules 10 (numbers 4 and 5) is installed, making module 5 a separate process section. The control system 17 sets drying chamber module 10 to "upward blowing through-flow mode," with a temperature of 55°C and a low airflow rate. This section is used for the final low-temperature softening and moisture equalization treatment of the material.

[0056] In another preferred embodiment, for precision materials that require strict control of the drying temperature profile, the entire drying path is configured in process segments. Each drying chamber module 10 maintains the installation state of the detachable isolation piece 114, and the temperature, humidity and flow path of each module are precisely controlled by the control system 17 to form an ideal temperature profile.

[0057] For example, in the staggered drying process of dehydrated carrot slices, a drying line consisting of three drying chamber modules (10) connected in series is used.

[0058] Step 1: Configure the entire drying path The entire drying path adopts a "process segmented section" configuration. Specifically, the operator keeps the detachable isolation pieces 114 between drying chamber modules 10 1 and 2, and between 2 and 3, in the installed state, thereby forming three independent drying environments.

[0059] Step 2: Set process parameters for each section ① Using the control system 17, the drying chamber module 10 is set to "upward blowing through-flow mode" and the temperature is set to 75℃. This step is used for rapid surface shaping and color protection of wet slices.

[0060] ② Using the control system 17, the drying chamber module 10 is set to "downward blowing through-flow mode" and the temperature is set to 65℃. This step utilizes a strong penetrating airflow to efficiently dehydrate the partially dehydrated slices.

[0061] ③ Using the control system 17, the drying chamber module 10 of No. 3 is set to "top-blowing through-flow mode" and the temperature is set to 55℃. This step is used for the final low-temperature drying to ensure uniform dryness and smooth shape of the product.

[0062] Through the above steps, an alternating process flow of "upward blowing through flow - downward blowing through flow - upward blowing through flow" is achieved to adapt to the changes in the physical properties of the material at different drying stages.

[0063] For example, in the multi-stage continuous drying process of the Chinese medicinal herb kudzu root, a drying line consisting of six drying chamber modules (10) connected in series is used. For composite processes involving multiple drying stages, a mixed arrangement method is used to configure the entire drying path, which is configured according to the arrangement method of "functional extension section → process segment section → functional extension section". Step 1: Configure the preheating section (modules 1-2). Remove the detachable separator 114 between drying chamber modules 10 and 10, connecting the chambers of the two modules to form a functional expansion section. Using the control system 17, uniformly set modules 1-2 to "downward-blowing through-flow mode," with a temperature of 60℃ and a medium airflow rate. This section is used to preheat sliced ​​kudzu root with high moisture content, ensuring a uniform temperature rise in preparation for subsequent drying.

[0064] Step 2: Configure the gradient drying sections (modules 3-4). Install the detachable separators 114 between modules 2 and 3, and between modules 3 and 4, forming two independent process sections. Using the control system 17, set module 3 to "upward blowing through-flow mode" at 70℃; and module 4 to "downward blowing through-flow mode" at 65℃. These sections are used for rapid surface drying and deep internal dehydration of kudzu root, respectively, creating a dual change in temperature gradient and airflow direction to improve drying efficiency.

[0065] Step 3: Configure the cooling and moisture equalization zone (modules 5-6). Remove the detachable separator 114 between modules 4 and 5, and between modules 5 and 6, to create a functional expansion zone. Using the control system 17, uniformly set modules 5-6 to "upward blowing through-flow mode," with a temperature of 50℃ and a low airflow rate. This zone is used for the slow cooling and moisture equalization of the dried kudzu root, ensuring a uniform moisture content in the finished product.

[0066] Through the above steps, a hybrid process flow of "functional expansion (preheating) → process segmentation (gradient drying) → functional expansion (cooling and humidification)" is realized, making full use of the process arrangement freedom provided by the modular design of this application.

[0067] Example 5 This embodiment further illustrates the automated control method of the control system 17 based on embodiments one to four.

[0068] The control system 17 is used to electrically connect to and control the airflow switching mechanism 16 (such as the actuator of the air valve group) and the heating circulation unit 12 (such as the frequency converter of the circulating fan 122 and the electrically controlled regulating valve of the heat exchanger 124) of each drying chamber module 10, and to receive signals from the temperature and humidity sensors in the upper air chamber 111 and the lower air chamber 112 to perform linkage control according to preset instructions.

[0069] The control system 17 consists of a programmable logic controller (PLC), distributed I / O modules, a human-machine interface (HMI), and a communication network. The PLC is hard-wired to the airflow switching mechanism 16 (valve assembly) actuator of each drying chamber module 10, the frequency converter of the circulating fan 122 of the heating circulation unit 12, the electrically controlled regulating valve of the heat exchanger 124, the start / stop device of the dehumidification fan, and temperature and humidity sensors. The HMI is equipped with a process formula database, which includes preset instruction control programs for top-blowing mode, bottom-blowing mode, and mixing mode.

[0070] When the drying chamber module 10 is in the top blowing mode, the control system adjusts the opening of the upper air inlet valve 161, the speed of the circulating fan 122 and the heating power of the heat exchanger 124 in real time according to the feedback signals from the temperature and humidity sensors of the upper air blowing chamber 111 and the return air channel 14, while closing the lower air inlet valve 162, the upper return air valve 163 and the upper exhaust valve 165.

[0071] When the drying chamber module 10 is in the down-blowing mode, the opening degree of the air inlet lower valve 162 and the opening frequency of the exhaust lower valve 166 are dynamically adjusted through the closed-loop control algorithm, while the air inlet upper valve 161, the return air lower valve 164 and the exhaust upper valve 165 are closed.

[0072] In hybrid mode (where the entire drying path includes multiple process sections), sensor data from multiple modules are uploaded to the central controller via a communication protocol (such as Modbus-TCP). After weighted calculation, joint control commands are generated to synchronously adjust the valve configurations and heating parameters of adjacent modules, ensuring that the temperature and humidity parameters of each process section accurately match changes in material characteristics.

[0073] Through the above technical solution, this application achieves intelligent linkage control of drying process parameters, solving the problem of lagging process adjustment caused by the single control method in traditional equipment. By using a central controller to coordinate the control of multiple actuator modules, different drying modes can be quickly switched without stopping the machine, ensuring that the temperature and humidity parameters of each process section accurately match changes in material characteristics. Based on a closed-loop adjustment mechanism with real-time sensor feedback, uneven drying caused by environmental fluctuations or differences in material state is effectively suppressed, significantly improving drying efficiency and quality stability under complex process combinations.

[0074] When the material type changes, the operator only needs to call the corresponding process formula through the human-machine interface, and the control system 17 can automatically adjust the operating parameters of the airflow switching mechanism 16 and the heating circulation unit 12 of each module to realize the online switching of the drying process without stopping the machine or replacing equipment components.

[0075] Finally, it should be noted that, 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 application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0076] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0077] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0078] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A drying method for a modular through-flow belt dryer, the dryer comprising at least two drying chamber modules (10) connected in series, each of the drying chamber modules (10) having an upper blowing chamber (111) and a lower blowing chamber (112) located on both sides of a mesh belt conveyor system (2), characterized in that: In each of the drying chamber modules (10), the flow direction of hot air in each drying chamber module (10) is independently configured by the airflow switching mechanism (16). The hot air is selectively directed to pass through the material layer on the mesh belt conveyor system (2) from the upper blowing chamber (111) to the lower blowing chamber (112) to form an upward blowing flow path, or to pass through the material layer on the mesh belt conveyor system (2) from the lower blowing chamber (112) to the upper blowing chamber (111) to form a downward blowing flow path. This establishes an airflow circulation in each drying chamber module (10) in which the flow direction can be independently configured.

2. The drying method according to claim 1, characterized in that: In the upward blowing flow path, hot air is introduced into the upward blowing chamber (111) through the air inlet channel (13), passes downward through the material layer on the mesh belt conveyor system (2) and enters the downward blowing chamber (112), and then returns to the heating circulation unit (12) through the return air channel (14). At the same time, part of the humid airflow is discharged from the side of the downward blowing chamber (112) through the dehumidification channel (15). In the downward blowing flow path, hot air is introduced into the downward blowing chamber (112) through the air inlet channel (13), passes upward through the material layer on the mesh belt conveyor system (2) and enters the upward blowing chamber (111), and then returns to the heating circulation unit (12) through the return air channel (14). At the same time, part of the humid airflow is discharged from the side of the upward blowing chamber (111) through the dehumidification channel (15).

3. The drying method according to claim 1, characterized in that: At least two adjacent drying chamber modules (10) are isolated from each other, and the at least two drying chamber modules (10) are configured with different flow paths, so that the material undergoes flow drying in different directions along the conveying direction, forming process segment sections.

4. The drying method according to claim 1, characterized in that: At least two adjacent drying chamber modules (10) have corresponding upper air blowing chambers (111) that are interconnected and corresponding lower air blowing chambers (112) that are interconnected. The at least two drying chamber modules (10) are configured with the same flow path to form a functional extension section.

5. The drying method according to claim 3 or 4, characterized in that: By isolating or connecting the chambers between the drying chamber modules (10) and independently configuring the flow paths of each module, the entire drying path can selectively include any combination of at least one process segment and / or at least one functional extension segment.

6. A modular through-flow belt dryer for implementing the drying method according to any one of claims 1 to 5, comprising a drying chamber (1) and a mesh belt conveyor system (2) penetrating the drying chamber (1), wherein the drying chamber (1) is composed of at least two drying chamber modules (10) connected in series, each of the drying chamber modules (10) comprising a drying chamber unit (11) and a heating circulation unit (12), wherein the drying chamber unit (11) has an upper blowing chamber (111) and a lower blowing chamber (112) located on both sides of the mesh belt conveyor system (2), characterized in that: The heating circulation unit (12) is connected to both the upper air chamber (111) and the lower air chamber (112). Each drying chamber module (10) also includes an airflow switching mechanism (16) for selectively allowing hot air from the heating circulation unit (12) to pass through the mesh belt conveyor system (2) from above or below.

7. The modular cross-flow belt dryer according to claim 6, characterized in that: A detachable isolation component (114) is provided between adjacent drying chamber modules (10). When installed, the detachable isolation component (114) isolates the respective chambers of the adjacent drying chamber modules (10). When removed, it connects the corresponding upper air blowing chambers (111) and the corresponding lower air blowing chambers (112) between the adjacent drying chamber modules (10).

8. The modular cross-flow belt dryer according to claim 6, characterized in that: The heating circulation unit (12) includes a makeup air chamber (121), a circulating fan (122), a heating buffer chamber (123), and a heat exchanger (124). The makeup air chamber (121) is located on the inlet side of the circulating fan (122), and the heating buffer chamber (123) is located on the inlet side of the heat exchanger (124). The outlet of the heat exchanger (124) is connected to the air inlet channel (13), and the makeup air chamber (121) is provided with a makeup air port (125) and is connected to the return air channel (14).

9. The modular cross-flow belt dryer according to claim 6, characterized in that: The heating circulation unit (12) is connected to the upper blowing chamber (111) and the lower blowing chamber (112) through the air inlet channel (13) and the air return channel (14). The drying chamber unit (11) is also provided with a dehumidification channel (15) connected to the upper blowing chamber (111) and the lower blowing chamber (112). The airflow switching mechanism (16) is a valve group. The valve group includes an upper air inlet valve (161), a lower air inlet valve (162), and a lower air return valve (163) disposed at the connection between the air inlet channel (13), the air return channel (14), and the dehumidification channel (15) and the upper blowing chamber (111) and the lower blowing chamber (112). 63) Return air lower valve (164), exhaust air upper valve (165) and exhaust air lower valve (166); When the drying chamber module (10) is in the upward blowing through-flow mode, the inlet air lower valve (162), return air upper valve (163) and exhaust air upper valve (165) are closed, and the inlet air upper valve (161), return air lower valve (164) and exhaust air lower valve (166) are open; When the drying chamber module (10) is in the downward blowing through-flow mode, the inlet air upper valve (161), return air lower valve (164) and exhaust air lower valve (166) are closed, and the inlet air lower valve (162), return air upper valve (163) and exhaust air upper valve (165) are open.

10. The modular cross-flow belt dryer according to claim 6, characterized in that: It also includes a control system (17) for electrically connecting and controlling the airflow switching mechanism (16) and the heating circulation unit (12) of each of the drying chamber modules (10), and receiving signals from the temperature and humidity sensors in the upper air chamber (111) and the lower air chamber (112) to perform linkage control according to preset instructions.

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