Water content on-line detection device, belt dryer and water content uniformity control method thereof

Abstract

The application relates to a water content online detection device, a belt dryer and a water content uniformity control method thereof. The water content online detection device comprises a sampling module, a detection module and a control module. The sampling module comprises a shell unit and a plurality of first driving units. The shell unit has a plurality of sampling ports arranged at intervals. The first driving units correspond to the sampling ports one by one, and the output ends of the first driving units are used for covering or exposing the sampling ports. The detection module comprises a detection unit and a second driving unit. The upper opening of the detection unit is connected with the lower opening of the shell unit. The output end of the second driving unit is used for covering or exposing the lower opening of the detection unit. The control module is in communication connection with the first driving units, the second driving unit and the detection unit, respectively. The control module is used for controlling the plurality of first driving units to expose the sampling ports in sequence. After the first driving units expose the sampling ports, the second driving units cover the lower opening of the detection unit, and the material in the detection unit is accumulated to a set amount, the material water content data is acquired, and the online automatic detection of the water content of the multi-point material is realized.

Description

Technical Field

[0001] This application relates to the field of online moisture monitoring technology, and in particular to online moisture detection devices, belt dryers, and methods for controlling the uniformity of moisture content. Background Technology

[0002] Belt dryers consist of a drying unit, a conveyor belt, and a hopper. During drying, the material is evenly distributed on the conveyor belt and transported to the drying unit for drying. After drying, the material is discharged from the hopper. They can dry materials in large quantities and continuously, and are widely used in industries such as chemical, food, pharmaceutical, building materials, and electronics.

[0003] In material drying production, the moisture content of the material determines product quality. Excessive moisture leads to spoilage during storage, while insufficient moisture causes losses for the enterprise. On the other hand, material moisture content reflects the drying effect and is an important indicator of belt dryer performance. During the drying process, the operating parameters of the belt dryer are adjusted based on the moisture content of the dried material to control product quality.

[0004] Currently, material moisture detection mainly includes two methods: 1) Manual measurement: Operators take samples sequentially at five evenly distributed locations on the conveyor belt according to national standards, and detect the moisture content using a rapid moisture meter or oven method. After the test, the results are fed back to the control personnel for manual adjustment. However, this method is labor-intensive, costly, requires coordination between the testing and control personnel, and is prone to errors. Moreover, there is a certain delay in the control personnel adjusting the control parameters based on the feedback test results, which affects product quality. 2) Online detection: For example, patent CN112212676A detects the material layer thickness and changes the fabric parameters to make the material layer thickness uniform. The material moisture is automatically detected by an online moisture sampling device. However, this detection method assumes that uniform material layer thickness means uniform material moisture. In actual production, the material layer thickness and moisture uniformity do not completely correspond, and manual detection of moisture and adjustment of fabric parameters are still required. Summary of the Invention

[0005] Based on this, an online moisture detection device, a belt dryer, and a method for controlling the moisture uniformity of the belt dryer are provided. The online moisture detection device can realize online automatic detection of moisture in materials at multiple points, which facilitates intelligent and unmanned operation and timely adjustment of the control parameters of the belt dryer.

[0006] This application provides an online moisture detection device, installed in the feed hopper of a belt dryer, comprising:

[0007] The sampling module includes a housing unit and multiple first drive units. The housing unit has multiple sampling ports spaced apart along the width direction of the conveyor belt of the belt dryer and used to receive materials. The first drive units correspond one-to-one with the sampling ports and their output ends are used to cover or expose the sampling ports.

[0008] The detection module includes a detection unit and a second drive unit. The upper opening of the detection unit is connected to the lower opening of the housing unit for detecting the moisture content of the material. The output end of the second drive unit is used to cover or expose the lower opening of the detection unit.

[0009] The control module is communicatively connected to the first drive unit, the second drive unit, and the detection unit, and is used to control multiple first drive units to sequentially expose the sampling port, and to acquire material moisture data after controlling the first drive unit to expose the sampling port, the second drive unit to cover the lower opening of the detection unit, and the material accumulation in the detection unit to a set amount.

[0010] When the aforementioned online moisture detection device needs to detect the moisture content of materials, the control module sends an action signal to the first drive unit and the second drive unit. The output end of the second drive unit activates and covers the lower opening of the detection unit, while the output end of the first drive unit activates and exposes the sampling port. At this time, the material falling from the conveyor belt enters the detection unit through the sampling port. After the material accumulates to a set amount in the detection unit, the control module acquires the material moisture data collected by the detection unit. After acquiring the material moisture data, the control module sends a response signal to the first drive unit and the second drive unit. The output end of the first drive unit activates and covers the sampling port, while the output end of the second drive unit activates and exposes the lower opening of the detection unit. At this time, the material accumulated in the detection unit falls into the hopper through the lower opening. The material cannot enter through the sampling port and falls directly into the hopper. The material moisture detection at one sampling port is completed. The control module controls the sequential automatic detection of different sampling ports. This material moisture detection is a multi-point automatic sampling detection, which does not require manual operation, making it easy to achieve intelligent and unmanned operation. Moreover, it can provide timely feedback on the detection results, which is convenient for adjusting the control parameters of the belt dryer.

[0011] In one embodiment, the housing unit includes a collection pipe, a support beam, and multiple sampling pipes. The upper end of the collection pipe forms multiple upper openings, and the lower end forms a lower opening connected to the upper opening of the detection unit. The sampling pipes correspond one-to-one with the upper openings of the collection pipe and are connected as a whole to form the sampling port. The support beam passes through the multiple sampling pipes sequentially along the width direction of the conveyor belt of the belt dryer and is installed inside the discharge hopper.

[0012] In one embodiment, the first drive unit includes a first rotary cylinder, a first bracket, a first rotating shaft, a first connecting sleeve, two first bearings, and a cover plate. The first rotary cylinder is communicatively connected to the control module. Its cylinder body is mounted on the hopper via the first bracket, and its extension shaft is connected to the first rotating shaft via the first connecting sleeve. The first rotating shaft passes through the sampling tube along the length of the conveyor belt of the belt dryer and is mounted on the hopper via the two first bearings. The cover plate is fixed on the first rotating shaft and can cover the sampling tube.

[0013] In one embodiment, the upper end face of the sampling tube is an inclined surface at a set acute angle to the vertical direction, and the cover plate is an elliptical plate structure that matches the inclined surface.

[0014] In one embodiment, the number of sampling ports is ≥5, the collecting pipe includes a flange, two first pipe bodies and multiple second pipe bodies, the second pipe bodies are connected and communicate with the first pipe bodies in a vertical direction, the two first pipe bodies are respectively arranged at a set acute angle with the vertical direction and are symmetrically arranged on the flange about the vertical direction, the flange is connected to the upper opening of the detection unit, and the sampling pipe is connected to the first pipe body or the second pipe body.

[0015] In one embodiment, the detection unit includes a detection shell, a moisture detection sensor, and a material level sensor. The detection shell is a cavity structure with openings at both ends and a funnel-shaped flow channel formed inside. The moisture detection sensor is disposed in the detection shell, and the material level sensor is disposed in the detection shell and located above the moisture detection sensor. The moisture detection sensor and the material level sensor are respectively communicatively connected to the control module.

[0016] In one embodiment, the second drive unit includes a second rotary cylinder, a cylinder seat, a bushing, a swing shaft, two second bearings, and a baffle. The second rotary cylinder is communicatively connected to the control module. Its cylinder body is mounted on the detection housing through the cylinder seat, and its extension shaft is connected to the swing shaft through the bushing. The swing shaft extends into and is mounted on the detection housing through the two second bearings. The baffle is connected to the swing shaft.

[0017] In addition, this application also provides a belt dryer, comprising:

[0018] A drying oven, including a heat source for drying materials;

[0019] A conveyor belt, installed inside the drying chamber, is used to transport materials;

[0020] A material spreader, including a chute, which is oscillatingly disposed above the conveyor belt along the belt length direction for spreading material on the conveyor belt;

[0021] An exhaust module, connected to the drying chamber, includes a damper for adjusting the exhaust volume;

[0022] The feeding hopper is connected to the discharge port of the drying box and is located directly below the material distributor;

[0023] The online moisture detection device as described in any of the above technical solutions is located in the feeding hopper.

[0024] In the aforementioned belt dryer, the material enters the distributor, flows through the chute into the drying chamber, and is spread on the conveyor belt. The conveyor belt moves the material to the heat source for drying. The dried moisture passes through the damper into the exhaust module and is then discharged. The dried material falls from the conveyor belt into the hopper. When material moisture detection is required, the control module controls the automatic detection of different sampling ports in sequence. When each sampling port is detected, the control module sends an action signal to the first drive unit and the second drive unit, covering the lower opening of the detection unit and exposing the sampling port. The material enters the detection unit through the sampling port, and after the material accumulates to a set amount in the detection unit, the control module acquires the material moisture data collected by the detection unit. After acquiring the material moisture data, the control module sends a reply signal to the first drive unit and the second drive unit, covering the sampling port and exposing the lower opening of the detection unit. The material in the detection unit falls into the hopper, as it cannot enter through the sampling port and falls directly into the hopper. Because the online moisture detection device detects material moisture through multi-point automatic sampling, it requires no manual operation, making it easy to achieve intelligent and unmanned operation. Moreover, it can provide timely feedback on the detection results, which facilitates the adjustment of the control parameters of the belt dryer, improves the automation level and reliability of the belt dryer, and enhances the material drying effect.

[0025] In addition, this application also provides a method for controlling the moisture uniformity of a belt dryer as described in the above technical solution, comprising the following steps:

[0026] Step S1: Obtain material moisture data from multiple sampling ports;

[0027] Step S2: Using the material moisture data of one of the middle sampling ports as a benchmark, calculate the first moisture deviation of the material moisture data of the remaining sampling ports. When the first moisture deviation falls outside the preset first allowable deviation, adjust the movement frequency of the chute directly above the sampling port.

[0028] Step S3: Calculate the average value of material moisture data from multiple sampling ports, and calculate the second moisture deviation between the average value and the target moisture content of the material. When the second moisture deviation falls outside the preset second allowable deviation, adjust the damper opening and the heat source temperature.

[0029] Step S4: After a drying cycle, repeat steps S1 and S2 until the first moisture deviation falls within the first allowable deviation and the second moisture deviation falls within the second allowable deviation, and then the chute maintains its motion frequency to spread the coating.

[0030] In the above-mentioned method for controlling the uniformity of moisture in a belt dryer, material moisture data from multiple sampling ports are collected by an online moisture detection device, and a first moisture deviation and a second moisture error are calculated. The movement frequency of the chute is adjusted according to the first moisture deviation and the first allowable deviation to ensure that the uniformity of moisture in the same batch remains consistent. The damper opening and heat source temperature are adjusted according to the second moisture deviation and the second allowable deviation to ensure that the uniformity of moisture in different batches remains consistent. In the specific control operation, firstly, through step S1, the online moisture detection device sequentially acquires and records the material moisture data from multiple sampling ports; then, through step S2, the online moisture detection device uses the material moisture data from one of the middle sampling ports as a benchmark, and compares the material moisture data from the remaining sampling ports with the benchmark to obtain multiple first moisture deviations. When the first moisture deviation falls outside the preset first allowable deviation, the movement frequency of the chute directly above the sampling port is adjusted to make the material thickness at the corresponding position on the conveyor belt different; next, through step S3, the online moisture detection device calculates the average value of the material moisture data from multiple sampling ports, and calculates the second moisture deviation between the average value and the target moisture content of the material. When the second moisture deviation falls outside the preset second allowable deviation, the damper opening and heat source temperature are adjusted to adjust the drying parameters of the belt dryer; finally, through step S4, after one drying cycle, steps S1 and S2 are repeated until the first moisture deviation falls within the first allowable deviation and the second moisture deviation falls within the second allowable deviation, and then the chute maintains its movement frequency to spread the coating. At this time, the moisture content of the material dried by the belt dryer is uniform.

[0031] In one embodiment, step S2 specifically includes: when the first moisture deviation is positive, increasing the movement frequency of the chute directly above the sampling port; when the first moisture deviation is negative, decreasing the movement frequency of the chute directly above the sampling port.

[0032] In one embodiment, step S3 specifically includes: when the second moisture deviation is positive, increasing the damper opening and the heat source temperature; when the second moisture deviation is negative, decreasing the damper opening and the heat source temperature. Attached Figure Description

[0033] Figure 1 This is a front view of a belt dryer provided in an embodiment of this application.

[0034] Figure 2 This is a schematic diagram of the structure of a module consisting of an online moisture detection device and a feeding hopper provided in an embodiment of this application.

[0035] Figure 3 This is a schematic diagram of the structure of an online moisture detection device provided in an embodiment of this application.

[0036] Figure 4 This is a schematic diagram of the structure of the removal detection module of the online moisture detection device provided in an embodiment of this application.

[0037] Figure 5 This is a schematic diagram of the structure of the module consisting of the sampling tube and the first driving unit in an online moisture detection device provided in an embodiment of this application.

[0038] Figure 6 This is a schematic diagram of the detection module in an online moisture detection device provided in an embodiment of this application.

[0039] Figure 7 for Figure 6 A cross-sectional view of the detection module.

[0040] Figure 8 This is a top view of a belt dryer provided in an embodiment of this application.

[0041] Figure 9 This is a schematic diagram of the fabric distributor and its speed control point in a belt dryer provided in an embodiment of this application.

[0042] Figure 10 This is a schematic diagram of the structure of the damper in a belt dryer provided in an embodiment of this application.

[0043] Figure 11 This is a schematic flowchart of a control method for a belt dryer provided in an embodiment of this application.

[0044] Figure label:

[0045] 01. Belt dryer;

[0046] 10. Online moisture detection device;

[0047] 100. Sampling module; 110. Housing unit; 111. Sampling port; 112. Manifold; 1121. Flange; 1122. First pipe body; 1123. Second pipe body; 113. Support beam; 114. Sampling tube; 120. First drive unit; 121. First rotary cylinder; 122. First bracket; 123. First rotating shaft; 124. First connecting sleeve; 125. First bearing; 126. Cover plate;

[0048] 200. Detection module; 210. Detection unit; 211. Detection housing; 212. Moisture detection sensor; 213. Material level sensor; 220. Second drive unit; 221. Second rotary cylinder; 222. Cylinder seat; 223. Bushing; 224. Swing shaft; 225. Second bearing; 226. Baffle;

[0049] 20. Feed hopper;

[0050] 30. Conveyor belt; X, first direction; Y, second direction; Z, third direction;

[0051] 40. Fabric distributor; 41. Fabric housing; 42. Chute; 43. Third drive unit; 44. Speed ​​control point;

[0052] 50. Drying oven; 51. Oven body; 51a. Air inlet; 51b. Exhaust outlet; 52. Heat source; 53. Fan;

[0053] 60. Exhaust module; 61. Air network; 61a. Air duct; 61b. Dehumidification fan; 61c. Temperature and humidity sensor; 62. Air damper; 62a. Air damper housing; 62b. Air damper plate; 62c. Fourth drive unit. Detailed Implementation

[0054] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0055] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0060] like Figure 1 as well as Figure 2 As shown, this application provides an online moisture detection device 10, applied in a belt dryer 01. The online moisture detection device 10 is installed on the feed hopper 20 of the belt dryer 01 and is used to detect the moisture content of material falling from the discharge port of the conveyor belt 30 into the feed hopper 20. For ease of description, the width direction of the conveyor belt 30 is defined as the first direction X, the length direction of the conveyor belt 30 as the second direction Y, and the vertical direction as the third direction Z. The first direction X, the second direction Y, and the third direction Z are all perpendicular to each other. The online moisture detection device 10 includes a sampling module 100, a detection module 200, and a control module. The sampling module 100 is located above the detection module 200 along the third direction Z. The control module is communicatively connected to the sampling module 100 and the detection module 200 via cables or other means.

[0061] Please refer to the above. Figure 3 as well as Figure 4 In the online moisture detection device 10, the sampling module 100 includes a housing unit 110 and multiple first drive units 120. The housing unit 110 has multiple sampling ports 111, which are spaced apart along a first direction X, and are used to receive falling material. Each first drive unit 120 corresponds to one sampling port 111, and the output end of each first drive unit 120 is used to cover or expose the sampling port 111. In a specific configuration, the housing unit 110 is disposed inside the hopper 20 and located below the end face of the hopper 20, and the fixed ends of the first drive units 120 are mounted on the hopper 20.

[0062] The housing unit 110 has various structural forms. In one preferred embodiment, please refer to... Figure 3 as well as Figure 4The housing unit 110 includes a collecting pipe 112, a supporting beam 113, and multiple sampling pipes 114. The upper end of the collecting pipe 112 forms multiple upper openings, and the lower end of the collecting pipe 112 forms a lower opening. The lower opening of the collecting pipe 112 connects to the upper opening of the detection module 200. Each sampling pipe 114 corresponds to one of the upper openings of the collecting pipe 112, and the sampling pipe 114 is integrated with the upper opening of the collecting pipe 112 to form a sampling port 111. The supporting beam 113 passes through multiple sampling pipes 114 sequentially along the first direction X, and the supporting beam 113 is installed inside the discharge hopper 20. In a specific configuration, the supporting beam 113 and the discharge hopper 20 are fixed together by welding, threaded connection, snap-fit ​​connection, or other methods. The sampling pipes 114 and the collecting pipe 112 are also fixed together by convex-concave fit, threaded connection, or snap-fit ​​connection. During the specific flow of material in the housing unit 110, the falling material falls from the conveyor belt 30 into the hopper 20, and enters through the upper opening of the sampling tube 114. After falling through the sampling tube 114 into the collecting tube 112, it enters the detection module 200 through the lower opening of the collecting tube 112 and the upper opening of the detection module 200 for detection. Therefore, multi-point detection of the housing unit 110 can be achieved through multiple sampling tubes 114.

[0063] The first drive unit 120 can have various structural forms, including a stepper motor, a motor + gear mechanism, or a telescopic cylinder. For ease of control of the opening and closing of the sampling port 111 and to simplify the structure, specific details are provided below. Figure 5The first drive unit 120 includes a first rotary cylinder 121, a first bracket 122, a first rotating shaft 123, a first connecting sleeve 124, two first bearings 125, and a cover plate 126. The first rotary cylinder 121 is connected to the control module via a cable. The cylinder body of the first rotary cylinder 121 is mounted on the hopper 20 via the first bracket 122, and the extension shaft of the first rotary cylinder 121 is connected to the first rotating shaft 123 via the first connecting sleeve 124. The first rotating shaft 123 passes through the sampling tube 114 in the second direction Y, and is mounted on the hopper 20 via the two first bearings 125. The cover plate 126 is fixed to the first rotating shaft 123 by means of threaded connection, welding, pin connection, etc., and can cover the sampling tube 114. In specific settings, the first bearing 125 can be a rotary bearing seat, or other structural forms that meet the requirements. In operation, the control module sends an action signal to the first rotary cylinder 121, causing its extension shaft to rotate. This rotation drives the first connecting sleeve 124 and the first rotating shaft 123 to rotate, which in turn causes the cover plate 126 to rotate. This changes the state between the cover plate 126 and the upper opening of the sampling tube 114, allowing the upper opening of the sampling tube 114 to switch between being exposed and covered. When the cover plate 126 rotates to the third direction Z to expose the upper opening of the sampling tube 114, the material falls directly through the upper opening of the sampling tube 114. When the cover plate 126 rotates to cover the upper opening of the sampling tube 114, the material is blocked by the cover plate 126 and cannot enter the sampling tube 114.

[0064] For details regarding material slippage, please refer to [link / reference]. Figure 5 The upper surface of the sampling tube 114 is an inclined surface at a set acute angle to the third direction Z, so that the upper opening of the sampling tube 114 is inclined to the third direction Z. When the cover plate 126 is rotated to the third direction Z to expose the upper opening of the sampling tube 114, the material can be easily introduced into the sampling tube 114 along the inner wall of the sampling tube 114. The cover plate 126 is an elliptical plate structure, which matches the inclined surface. When the cover plate 126 is rotated to cover the upper opening of the sampling tube 114, the material falls onto the cover plate 126 and can slide smoothly down the surface of the cover plate 126 into the feed hopper 20. This can prevent material residue on the cover plate 126, avoid residual material from affecting the subsequent material moisture detection, and improve the reliability and accuracy of moisture detection.

[0065] The manifold 112 has various structural forms; for details, please refer to [reference needed]. Figure 3 as well as Figure 4The number of sampling ports 111 is ≥5, preferably 5, 6, 7 or more, with the specific number determined based on the width of the conveyor belt 30 and the moisture accuracy requirements. The collecting pipe 112 includes a flange 1121, two first pipe bodies 1122, and multiple second pipe bodies 1123. The second pipe bodies 1123 are connected to the first pipe bodies 1122 along a third direction Z, and the second pipe bodies 1123 and the first pipe bodies 1122 are in communication. The two first pipe bodies 1122 each form a set acute angle with the third direction Z, and the two first pipe bodies 1122 are symmetrically arranged on the flange 1121 about the third direction Z. The flange 1121 is connected to the upper opening of the detection module 200, and the sampling pipe 114 is connected to either the first pipe body 1122 or the second pipe body 1123. When the material falls, whether it enters the first pipe body 1122 through the sampling tube 114 or the second pipe body 1123 through the sampling tube 114, the material can fall quickly and easily, avoiding material retention and blockage, and improving detection efficiency and reliability. In specific settings, the flange 1121, the two first pipe bodies 1122, and the multiple second pipe bodies 1123 can be integrally formed or separately formed and then fixed together by snap-fit ​​connections, anti-convex and concave fits, threaded connections, etc.

[0066] Please refer to the above. Figure 6 as well as Figure 7 In the online moisture detection device 10, the detection module 200 includes a detection unit 210 and a second drive unit 220. The upper opening of the detection unit 210 is connected to the lower opening of the housing unit 110. The detection unit 210 is used to detect the moisture content of the material. The output end of the second drive unit 220 is used to cover or expose the lower opening of the detection unit 210. In a specific configuration, the detection unit 210 is placed inside the hopper 20, and the fixed end of the second drive unit 220 is mounted on the hopper 20.

[0067] The detection unit 210 has various structural forms. In one preferred embodiment, see below. Figure 6 as well as Figure 7The detection unit 210 includes a detection shell 211, a moisture detection sensor 212, and a level sensor 213. The detection shell 211 is a cavity structure with openings at both ends, and a funnel-shaped flow channel is formed inside the detection shell 211 to facilitate the falling and accumulation of materials. In a specific configuration, the detection shell 211 is connected to a flange 1121 to achieve the connection between the detection unit 210 and the shell unit 110. The moisture detection sensor 212 is disposed in the detection shell 211. This moisture detection sensor 212 can be a direct contact sensor or an indirect contact sensor. The level sensor 213 is disposed in the detection shell 211 and is located above the moisture detection sensor 212. It is used to obtain the amount of material accumulated in the detection shell 211. This level sensor 213 can be a photoelectric sensor or other forms that meet the requirements. The moisture detection sensor 212 and the level sensor 213 are respectively connected to the control module via cables. In actual operation, when the material accumulates in the detection shell 211 to the height of the material level sensor 213 in the third direction Z, the material level sensor 213 sends the material arrival information to the control module. At this time, the control module controls the moisture detection sensor 212 to collect the material moisture data.

[0068] The second drive unit 220 can have various structural forms, including a stepper motor, a motor + gear mechanism, or a telescopic cylinder. For easier control of the opening and closing of the lower opening of the detection unit 210 and to simplify the structure, please refer to [reference needed]. Figure 6 as well as Figure 7The second drive unit 220 includes a second rotary cylinder 221, a cylinder seat 222, a bushing 223, a swing shaft 224, two second bearings 225, and a baffle 226. The second rotary cylinder 221 is connected to the control module via a cable. The cylinder body of the second rotary cylinder 221 is mounted on the detection housing 211 via the cylinder seat 222, and the extension shaft of the second rotary cylinder 221 is connected to the swing shaft 224 via the bushing 223. The swing shaft 224 extends into the detection housing 211 and is mounted on the detection housing 211 via the two second bearings 225. The baffle 226 is connected to the swing shaft 224 via threaded connection, welding, pin connection, or other methods. In specific configurations, the second bearings 225 can be rotary bearing seats or other structural forms that meet the requirements. In actual operation, the control module sends an action signal to the second rotary cylinder 221. The extension shaft of the second rotary cylinder 221 rotates, causing the bushing 223 and the swing shaft 224 to rotate accordingly, which in turn causes the baffle 226 to rotate. The state between the baffle 226 and the lower opening of the detection shell 211 changes, thereby enabling the lower opening of the detection shell 211 to switch between being exposed and covered. When the baffle 226 rotates to the third direction Z to expose the lower opening of the detection shell 211, the material falls directly through the lower opening of the detection shell 211. When the baffle 226 rotates to cover the lower opening of the detection shell 211, the material accumulates on the baffle 226.

[0069] In the online moisture detection device 10, the control module is connected to the first drive unit 120, the second drive unit 220, and the detection unit 210 via cables. The control module controls the multiple first drive units 120 to sequentially expose the sampling port 111. For each sampling port 111, the control module controls the output of the first drive unit 120 to expose the sampling port 111, controls the output of the second drive unit 220 to cover the lower opening of the detection unit 210, and after a set amount of material accumulates inside the detection unit 210, controls the detection unit 210 to acquire the material moisture data. In specific settings, the control module can be a PLC (Programmable Logic Controller), a PCB (Printed Circuit Board), or other structural forms that meet the requirements.

[0070] When the aforementioned online moisture detection device 10 needs to detect the moisture content of materials, the control module sends an action signal to the first drive unit 120 and the second drive unit 220. The output end of the second drive unit 220 activates and covers the lower opening of the detection unit 210, while the output end of the first drive unit 120 activates and exposes the sampling port 111. At this time, the material falling from the conveyor belt 30 enters the detection unit 210 through the sampling port 111. After the material accumulates to a set amount in the detection unit 210, the control module acquires the material moisture data collected by the detection unit 210. After acquiring the material moisture data, the control module sends an action signal to the first drive unit 120 and the second drive unit 220. Upon receiving the response signal, the output of the first drive unit 120 activates and covers the sampling port 111, while the output of the second drive unit 220 activates and exposes the lower opening of the detection unit 210. At this time, the material accumulated inside the detection unit 210 falls into the hopper 20 through the lower opening. The material cannot enter through the sampling port 111 and falls directly into the hopper 20. The moisture content of the material at one sampling port 111 is detected. The control module controls the sequential automatic detection of different sampling ports 111. This material moisture detection is a multi-point automatic sampling detection, which does not require manual operation, making it easy to achieve intelligent and unmanned operation. Moreover, it can provide timely feedback on the detection results, which is convenient for adjusting the control parameters of the belt dryer 01.

[0071] In addition, this application also provides a belt dryer 01, which is also referred to herein. Figure 8 , Figure 9 , Figure 10 This belt dryer 01 is used to dry materials. It includes a hopper 20, a conveyor belt 30, a material distributor 40, a drying chamber 50, an exhaust module 60, and an online moisture detection device 10 as described in any of the above technical solutions.

[0072] The drying chamber 50 includes a chamber body 51 and a heat source 52 and a fan 53 disposed inside the chamber body 51. The chamber body 51 is provided with an air inlet 51a and a moisture outlet 51b. The heat source 52 is used to dry the material, and the fan 53 is used to supplement air from the outside through the air inlet 51a and form an airflow inside the chamber body 51 to dry the material.

[0073] The conveyor belt 30 is installed inside the housing 51 of the drying chamber 50, and the conveyor belt 30 is used to transport materials.

[0074] The material distributor 40 includes a material housing 41, a chute 42, and a third drive unit 43. The upper end of the material housing 41 forms a material inlet. The chute 42 is disposed on the material housing 41 and is connected to both the material inlet and the housing 51. The chute 42 is positioned above the conveyor belt 30 and can oscillate around a second direction Y. The chute 42 is used to spread material onto the conveyor belt 30. In a specific configuration, the fixed end of the third drive unit 43 is mounted on the material housing 41, and the output end of the third drive unit 43 extends along the second direction Y and is connected to the chute 42. The third drive unit 43 can be a servo motor, in which case a speed control point 44 can be inserted to change the rotational speed of the third drive unit 43. Alternatively, the third drive unit 43 can be a geared motor. The material housing 41 is equipped with proximity switches at different angles of the oscillation trajectory of the chute 42, so that the speed control point 44 of the third drive unit 43 is set at the corresponding proximity switch to change the rotational speed.

[0075] The exhaust module 60 includes an air network 61 and an air damper 62. The air network 61 includes an air duct 61a and a dehumidification fan 61b. A temperature and humidity sensor 61c is installed inside the air duct 61a to detect the temperature and humidity of the humid air inside the air duct 61a. The air damper 62 is connected to the housing 51 of the drying chamber 50 and is used to adjust the exhaust volume. In a specific configuration, the air damper 62 includes an air damper housing 62a, multiple air damper plates 62b, and a fourth drive unit 62c. The fourth drive unit 62c and the air damper plates 62b are arranged in a one-to-one correspondence. The fourth drive unit 62c can be a rotary motor. The fixed end of the fourth drive unit 62c is installed on the air damper housing 62a, and the output end extends into the air damper housing 62a and is connected to the air damper plates 62b. The fourth drive unit 62c changes the opening between adjacent air damper plates 62b to adjust the exhaust volume. In actual operation, the dehumidifying fan 61b draws out the moisture inside the housing 51 and enters the air duct 61a through the dehumidifying port 51b and the damper 62, and is finally discharged into the outside air.

[0076] The hopper 20 is connected to the discharge port of the body 51 of the drying chamber 50, and the hopper 20 is located directly below the distributor 40. An online moisture detection device 10 is installed inside the hopper 20.

[0077] In the aforementioned belt dryer 01, the material enters the distributor 40, passes through the chute 42 into the drying chamber 50, and is spread on the conveyor belt 30. The conveyor belt 30 moves the material to the heat source 52 for drying. The dried moisture passes through the damper 62 into the exhaust module 60 and is then discharged. The dried material falls from the conveyor belt 30 into the discharge hopper 20. When material moisture detection is required, the control module controls the sequential automatic detection of different sampling ports 111. When each sampling port 111 is detected, the control module sends an action signal to the first drive unit 120 and the second drive unit 220 to detect the moisture content. The lower opening of unit 210 is covered, while the sampling port 111 is exposed. Material enters the detection unit 210 through the sampling port 111. After the material accumulates to a set amount in the detection unit 210, the control module acquires the material moisture data collected by the detection unit 210. After acquiring the material moisture data, the control module sends a response signal to the first drive unit 120 and the second drive unit 220, covering the sampling port 111 and exposing the lower opening of the detection unit 210. The material in the detection unit 210 falls into the discharge hopper 20, as it cannot enter through the sampling port 111 and falls directly into the discharge hopper 20. Since the material moisture detection of the online moisture detection device 10 is a multi-point automatic sampling detection, no manual operation is required, facilitating intelligent and unmanned operation. Moreover, it can provide timely feedback on the detection results, making it easy to adjust the control parameters of the belt dryer 01, improving the automation level and reliability of the belt dryer 01, and enhancing the material drying effect.

[0078] In addition, such as Figure 11 As shown, this application also provides a method for controlling the moisture uniformity of the belt dryer 01 as described above, comprising the following steps:

[0079] Step S1: Obtain material moisture data from multiple sampling ports 111 using the online moisture detection device 10. For example, the online moisture detection device 10 has five sampling ports 111, and its control module stores a first allowable deviation Δw, the target moisture content w of the material, the movement frequency of the chute 42 directly above the sampling ports 111 as f1, f2, f3, f4, f5, and a second allowable deviation Δp. The online moisture detection device 10 sequentially collects and records the material moisture data w1, w2, w3, w4, w5 from the five sampling ports 111.

[0080] Step S2: Using the material moisture data of the middle sampling port 111 as a benchmark, calculate the first moisture deviation of the material moisture data of the remaining sampling ports 111. When the first moisture deviation falls outside the preset first allowable deviation, adjust the movement frequency of the chute 42 directly above the sampling port 111. For example, using the material moisture data w3 of the third sampling port 111 as a benchmark, the first moisture deviation of the material moisture data of the remaining sampling ports 111 is wi-w3, where i is 1, 2, 4, or 5. When wi-w3 falls outside Δw, the movement frequency of the chute 42 directly above the sampling port 111 needs to be adjusted automatically or manually.

[0081] In a preferred embodiment, step S2 specifically includes: when the first moisture deviation is positive, increasing the movement frequency of the chute 42 directly above the sampling port 111; when the first moisture deviation is negative, decreasing the movement frequency of the chute 42 directly above the sampling port 111. For example, when wi-w3 is positive and greater than Δw, the movement frequency of the chute 42 directly above the sampling port 111 increases by Δf; when wi-w3 is negative and greater than Δw, the movement frequency of the chute 42 directly above the sampling port 111 decreases by Δf. When the third drive unit 43 is a motor, the change in movement frequency is calculated using the formula: Δfi=(|wi-w3| / Δw)*Δf, to optimize the movement frequency adjustment process.

[0082] Step S3: Calculate the average value of the material moisture data from multiple sampling ports 111, and calculate the second moisture deviation between the average value and the target moisture content of the material. When the second moisture deviation falls outside the preset second allowable deviation, adjust the opening of the damper 62 and the temperature of the heat source 52. For example, the average value is calculated by the formula and the second moisture deviation is calculated by the formula. When it falls outside Δp, the opening of the damper 62 and the temperature of the heat source 52 need to be adjusted automatically or manually.

[0083] In a preferred embodiment, step S3 specifically includes: when the second moisture deviation is positive, increasing the opening of damper 62 and the temperature of heat source 52; when the second moisture deviation is negative, decreasing the opening of damper 62 and the temperature of heat source 52. For example, when the deviation is positive and greater than Δp, the opening of damper 62 increases by Δk, and the temperature of heat source 52 increases by Δr; when the deviation is negative and greater than Δp, the opening of damper 62 decreases by Δk, and the temperature of heat source 52 decreases by Δr. Δk and Δr are pre-stored in a corresponding table within the control module.

[0084] Step S4: After one drying cycle, repeat steps S1 and S2 until the first moisture deviation falls within the first allowable deviation and the second moisture deviation falls within the second allowable deviation. Afterward, the chute 42 maintains its operating frequency to spread the coating. For example, the drying cycle T is calculated using the formula T = F / power frequency * T0, where F is the operating frequency of the conveyor belt 30, power frequency refers to the normal frequency of local industrial electricity, and T0 is the drying time at the power frequency. When wi - w3 is less than Δw, the moisture uniformity adjustment stops, and the chute 42 continues to operate at the adjusted operating frequency.

[0085] It should be noted that after the moisture uniformity adjustment is completed during a batch production process, the change is generally very small and usually does not require readjustment. However, the moisture uniformity adjustment program in the control module can be restarted at intervals. In this case, the operating parameters of the feeder 40 are kept unchanged, and steps S1, S2, and S4 above are performed in sequence, automatically determining whether to adjust the feeder 40. When producing different batches of the same feed variety, the frequency of the fan 53 and the conveyor belt 30 of the dry belt dryer 01 remains unchanged. However, since the moisture content of different batches entering the belt dryer 01 may be different, and the temperature and humidity of the external environment may be different at different times, it will affect the drying process. In this case, other control parameters of the belt dryer 01 need to be adjusted. Other control parameters mainly include the opening degree of the damper 62 and the temperature of the heat source 52. The adjustment of other control parameters needs to be performed in sequence according to steps S1, S3, and S4 above.

[0086] In the above-mentioned method for controlling the moisture uniformity of the belt dryer 01, the online moisture detection device 10 collects material moisture data from multiple sampling ports 111 and calculates the first moisture deviation and the second moisture error. The movement frequency of the chute 42 is adjusted according to the first moisture deviation and the first allowable deviation to ensure consistent moisture uniformity within the same batch. The opening of the damper 62 and the temperature of the heat source 52 are adjusted according to the second moisture deviation and the second allowable deviation to ensure consistent moisture uniformity across different batches. In the specific control operation, firstly, through step S1, the online moisture detection device 10 sequentially acquires and records material moisture data from multiple sampling ports 111; then, through step S2, the online moisture detection device 10 uses the material moisture data from the middle sampling port 111 as a benchmark, and compares the material moisture data from the remaining sampling ports 111 with the benchmark to obtain multiple first moisture deviations. When the first moisture deviation falls outside the preset first allowable deviation, the movement frequency of the chute 42 at the position directly above the sampling port 111 is adjusted to ensure different material thicknesses at corresponding positions on the conveyor belt 30; then, through step S3, the online moisture detection device... The measuring device 10 calculates the average value of the material moisture data from multiple sampling ports 111, and calculates the second moisture deviation between the average value and the target moisture content of the material. When the second moisture deviation falls outside the preset second allowable deviation, the opening of the damper 62 and the temperature of the heat source 52 are adjusted to adjust the drying parameters of the belt dryer 01. Finally, through step S4, after one drying cycle, steps S1 and S2 are repeated until the first moisture deviation falls within the first allowable deviation and the second moisture deviation falls within the second allowable deviation. After that, the chute 42 maintains the movement frequency to spread the coating. At this time, the moisture content of the material dried by the belt dryer 01 is uniform.

[0087] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. An online moisture detection device, installed in the feed hopper of a belt dryer, characterized in that, include: The sampling module includes a housing unit and a plurality of first drive units fixedly installed on the hopper. The housing unit has a plurality of sampling ports spaced apart along the width direction of the conveyor belt of the belt dryer and used to receive materials. The first drive units correspond one-to-one with the sampling ports and their output ends are used to cover or expose the sampling ports. The detection module includes a detection unit and a second drive unit. The upper opening of the detection unit is connected to the lower opening of the housing unit for detecting the moisture content of the material. The output end of the second drive unit is used to cover or expose the lower opening of the detection unit. The control module is communicatively connected to the first drive unit, the second drive unit, and the detection unit, and is used to control multiple first drive units to expose the sampling port in sequence, and to acquire material moisture data after controlling the first drive unit to expose the sampling port, the second drive unit to cover the lower opening of the detection unit, and the material accumulation in the detection unit to a set amount. The housing unit includes a collection pipe, a support beam, and multiple sampling pipes. The upper end of the collection pipe forms multiple upper openings, and the lower end forms a lower opening that connects to the upper opening of the detection unit. The sampling pipes correspond one-to-one with the upper openings of the collection pipe and are connected as a whole to form the sampling port. The support beam passes through multiple sampling pipes sequentially along the width direction of the conveyor belt of the belt dryer and is installed inside the discharge hopper.

2. The online moisture detection device according to claim 1, characterized in that, The first drive unit includes a first rotary cylinder, a first bracket, a first rotating shaft, a first connecting sleeve, two first bearings, and a cover plate. The first rotary cylinder is communicatively connected to the control module. Its cylinder body is mounted on the hopper via the first bracket, and its extension shaft is connected to the first rotating shaft via the first connecting sleeve. The first rotating shaft passes through the sampling tube along the length of the conveyor belt of the belt dryer and is mounted on the hopper via the two first bearings. The cover plate is fixed on the first rotating shaft and can cover the sampling tube.

3. The online moisture detection device according to claim 2, characterized in that, The upper surface of the sampling tube is an inclined surface at a set acute angle to the vertical direction, and the cover plate is an elliptical plate structure that matches the inclined surface.

4. The online moisture detection device according to claim 1, characterized in that, The number of sampling ports is ≥5. The collection pipe includes a flange, two first pipe bodies and multiple second pipe bodies. The second pipe bodies are connected to and communicate with the first pipe bodies in the vertical direction. The two first pipe bodies are respectively arranged at a set acute angle with the vertical direction and are symmetrically arranged on the flange about the vertical direction. The flange is connected to the upper opening of the detection unit. The sampling pipe is connected to the first pipe body or the second pipe body.

5. The online moisture detection device according to claim 1, characterized in that, The detection unit includes a detection shell, a moisture detection sensor, and a material level sensor. The detection shell is a cavity structure with openings at both ends and a funnel-shaped flow channel formed inside. The moisture detection sensor is disposed in the detection shell, and the material level sensor is disposed in the detection shell and located above the moisture detection sensor. The moisture detection sensor and the material level sensor are respectively communicatively connected to the control module.

6. The online moisture detection device according to claim 5, characterized in that, The second drive unit includes a second rotary cylinder, a cylinder seat, a bushing, a swing shaft, two second bearings, and a baffle. The second rotary cylinder is communicatively connected to the control module. Its cylinder body is mounted on the detection housing through the cylinder seat, and its extension shaft is connected to the swing shaft through the bushing. The swing shaft extends into and is mounted on the detection housing through the two second bearings. The baffle is connected to the swing shaft.

7. A belt dryer, characterized in that, include: A drying oven, including a heat source for drying materials; A conveyor belt, installed inside the drying chamber, is used to transport materials; A material spreader, including a chute, which is oscillatingly disposed above the conveyor belt along the belt length direction for spreading material on the conveyor belt; An exhaust module, connected to the drying chamber, includes a damper for adjusting the exhaust volume; The feeding hopper is connected to the discharge port of the drying box and is located directly below the material distributor; The online moisture detection device as described in any one of claims 1-6 is located in the feeding hopper.

8. A method for controlling the moisture uniformity of a belt dryer as described in claim 7, characterized in that, Includes the following steps: Step S1: Obtain material moisture data from multiple sampling ports; Step S2: Using the material moisture data of one of the middle sampling ports as a benchmark, calculate the first moisture deviation of the material moisture data of the remaining sampling ports. When the first moisture deviation falls outside the preset first allowable deviation, adjust the movement frequency of the chute directly above the sampling port. Step S3: Calculate the average value of material moisture data from multiple sampling ports, and calculate the second moisture deviation between the average value and the target moisture content of the material. When the second moisture deviation falls outside the preset second allowable deviation, adjust the damper opening and the heat source temperature. Step S4: After a drying cycle, repeat steps S1 and S2 until the first moisture deviation falls within the preset first allowable deviation and the second moisture deviation falls within the preset second allowable deviation, and then the chute maintains its motion frequency to spread the coating.

9. The method for controlling the moisture uniformity of a belt dryer according to claim 8, characterized in that, Step S2 specifically includes: when the first moisture deviation is positive, increasing the movement frequency of the chute directly above the sampling port; when the first moisture deviation is negative, decreasing the movement frequency of the chute directly above the sampling port.

10. The method for controlling the moisture uniformity of a belt dryer according to claim 8, characterized in that, Step S3 specifically includes: when the second moisture deviation is positive, increasing the damper opening and the heat source temperature; when the second moisture deviation is negative, decreasing the damper opening and the heat source temperature.

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