An on-line weighing device, system and method for a thin layer drying test bench

Abstract

The application discloses a kind of online weighing devices for thin layer drying test bench, including tray, sealing ring, weighing ring, weighing sensor and base, the hollow cylindrical structure is arranged in the middle of base, base is connected with drying test bench;Weighing ring is set in the outer edge of base hollow cylindrical structure and is placed on the upper end of multiple weighing sensors that are evenly arranged on the base mesa around the hollow cylindrical structure, tray is nested in the outer edge of base hollow cylindrical structure and is placed on the upper end of weighing ring;When tray is nested in the outer edge of hollow cylindrical structure, sealing ring is arranged between the lower end of tray and the outer edge of hollow cylindrical structure;The central axis of the tray, sealing ring, weighing ring, base coincides.By sealing ring and weight sensor alternate working principle, the weight of material is measured in situ online quickly.This device structure is simple, easy to operate, can release manpower, greatly improve test efficiency.

Description

Technical Field

[0001] This invention belongs to the field of grain (oilseed) drying technology, specifically relating to an online weighing device, system and method for a thin-layer drying test bench. Background Technology

[0002] Thin-layer drying test benches are commonly used devices in the field of primary agricultural product processing to study the drying characteristics of materials. They are used to conduct experiments on the effects of different parameters such as temperature, wind speed, and drying time on the moisture content and drying quality of materials. Based on the direction of the drying airflow acting on the material, thin-layer test benches can be divided into two structures: vertical and horizontal. In the vertical structure, the airflow direction is opposite to the direction of material gravity, while in the horizontal structure, the airflow direction is perpendicular to the direction of material gravity. The drying test bench mainly reflects the change in moisture content of materials under certain conditions through changes in material weight; material weighing is the core step. Currently, the experiment is mainly constrained by the material weighing process, which requires manual operation, resulting in low efficiency and long processing time. Patent 1 (CN 202485765U) discloses an oil-sealed weighing device based on an electronic balance, which is bulky, complex in structure, susceptible to contamination from leaking sealing oil, and requires manual recording. Patent 2 (CN105767163B) discloses a thin-layer drying model method based on multiple detection variables such as temperature, humidity, ventilation volume, and wind speed. However, the large number of parameters easily introduces measurement errors, and manual weighing verification is required in actual experiments. Patent 3 (CN113091801A) discloses an online weighing technology applied to a horizontal crossflow drying test bench, but it is difficult to apply to a vertical drying test bench, mainly because it is affected by the high-temperature airflow, making it impossible to achieve in-situ real-time weight measurement. Therefore, how to provide a method for in-situ online real-time weighing of materials suitable for a vertical thin-layer drying test bench is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides an online weighing operation method and device for a thin-layer drying test bench, which solves the problem of online in-situ real-time measurement of material weight during thin-layer drying tests and enables fully automated operation of thin-layer drying tests.

[0004] The present invention adopts the following technical solution.

[0005] An online weighing device for a thin-layer drying test bench includes a tray, a sealing ring, a weighing ring, a weighing sensor, and a base. A hollow cylindrical structure is provided in the middle of the base. The base is placed on the drying test bench and connected to the main pipeline of the drying test bench.

[0006] The weighing ring is fitted around the outer edge of the hollow cylindrical structure of the base and placed above the multiple weighing sensors that are evenly arranged on the base platform around the hollow cylindrical structure. The tray is nested around the outer edge of the hollow cylindrical structure of the base and placed above the weighing ring.

[0007] When the tray is nested on the outer edge of the hollow cylindrical structure, a sealing ring is set between the lower end of the tray and the outer edge of the hollow cylindrical structure;

[0008] The central axes of the tray, sealing ring, weighing ring, and base coincide.

[0009] Furthermore, the tray includes two hollow cylindrical structures with different diameters, which are connected at one end. A circular connecting piece is provided at the connection point. The circular connecting piece is perpendicular to the central axis of the two hollow cylindrical structures, and the circular connecting piece matches the cross-section of the hollow cylindrical structure with the larger diameter.

[0010] The annular connector has a certain number of threaded holes spaced along the circumference, and the annular connector is connected to the screen plates with different screen hole diameters through the threaded holes.

[0011] Furthermore, the hollow cylindrical structure of the base is provided with a double-eared groove on its outer periphery for nesting the sealing ring; the sealing ring is a hollow circular ring structure, connected to one end of the hose, and the other end of the hose is connected to a quick-connect valve;

[0012] In the uninflated state, the sealing ring is completely embedded in the double-ear groove. In the inflated state, it is in the working state. In the inflated state, the circumference of the sealing ring expands outward, and the outer wall of the sealing ring protrudes from the outer edge of the double-ear groove, which is pressed against the inner wall of the tray nested into the outer edge of the hollow ring structure to form a closed space.

[0013] Furthermore, a diameter marking ring is provided on the side of the weighing ring that connects to the tray.

[0014] Furthermore, the central cylindrical structure of the base is nested with the tray, the base is connected to the main body of the drying test bench, and a fixing groove is provided on the side where the base connects to the main body of the drying test bench;

[0015] A bracket is provided on the side where the base is connected to the main body of the drying test bench. The bracket is inverted U-shaped, with the upper end of the bracket fixed to the lower surface of the base and the lower end providing an installation hole for the quick-connect valve.

[0016] The main air valve of the drying test bench is installed on the main pipeline.

[0017] Furthermore, the base is nested with an outer shell, the inner part of which has through holes, and the outer surface of which has ventilation holes.

[0018] An online weighing system for a drying test bench based on an online weighing device includes a CPU module, a timing module, a weight adjustment module, and an air valve adjustment module, wherein the CPU module is connected to the timing module, the weight adjustment module, and the air valve adjustment module;

[0019] The air valve adjustment module is connected to the quick-connect valve and the main air valve of the drying test bench. The CPU module controls the opening and closing of the main air valve and the sealing ring air valve of the drying test bench through the air valve adjustment module to achieve the drying of the sample in the drying test and the sealing between the tray and the base holding the sample during the online weighing process.

[0020] The CPU module is used to determine the moisture content of the sample based on the weight data before and after the test.

[0021] The timing module is used to control the timing during the drying test;

[0022] The weight adjustment module is connected to multiple weighing sensors to collect sample weight data before and after the drying test and upload it to the CPU module.

[0023] Furthermore, the online weighing system also includes a display module and a storage module;

[0024] The display module is connected to the CPU module and the weight adjustment module. It is used to display the name of the material to be dried, its weight, and the moisture content at each stage of the test. The display module can also be used to set the time interval for weighing the material during the drying test and the stop threshold for the moisture content of the material.

[0025] The storage module is connected to the CPU module and is used to store parameter settings and experimental data during operation, providing reference data for subsequent experiments.

[0026] The online weighing method for a drying test bench based on an online weighing system specifically includes the following steps:

[0027] Step 1: Select the type of material to be dried, enter the material name, initial moisture content, and set the weighing time interval, target moisture content, and safe moisture content threshold for the material.

[0028] Step 2: Place the material to be dried in a tray, place the tray with the material in an online weighing device, and after confirming that there is no abnormal change in the weight of the tray through the weight adjustment module, record the initial weight of the material.

[0029] Step 3: Open the main air valve and sealing ring air valve of the drying test bench through the air valve adjustment module to expand the sealing ring to the inflated state, then open the main air valve of the drying test bench to start the drying operation and record the test time.

[0030] Step 4: When the test time reaches the weighing interval, close the main air valve and sealing ring air valve of the drying test bench. If there is no abnormal change in the weight of the tray, weigh the material online to obtain the current material weight.

[0031] Step 5: Calculate the current moisture content of the material based on the initial weight of the material and the current weight of the material after the stage test. If the current moisture content of the material is close to the target moisture content and the error is less than the safe moisture content threshold, the material drying is completed and the test ends. Otherwise, repeat steps 3 to 5.

[0032] Furthermore, the method for determining whether the pallet weight change is abnormal is as follows:

[0033] When the outer edge of one end of the tray contacts the diameter marking ring on the weighing ring, the load cell senses the material and outputs a pressure signal to the weight adjustment module to trigger detection. After the weight adjustment module detects that the pressure signal has no obvious fluctuation and tends to be stable, it determines whether the signals of all load cells are consistent. If the pressure signals of all load cells are inconsistent, it indicates that the material in the tray is in an abnormal state and the tray needs to be removed again to adjust the material state before weighing again. If the pressure signals of all load cells are consistent, it is determined that the change in the weight of the tray is normal.

[0034] The advantages of this invention are that, compared with existing technologies, it has a simple structure, is easy to operate, and can greatly improve experimental efficiency. It mainly employs a combination of a weighing sensor and an inflatable sealing ring, utilizing the principle of their alternating cyclic operation to develop online material weighing technology and design an online precision weighing device. This enables the determination of material uniformity and in-situ, online, precise, and rapid weight measurement. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of an online weighing device for a drying test bench provided by the present invention;

[0036] Figure 2 This is an exploded view of an online weighing device for a drying test bench provided by the present invention;

[0037] Figure 3 This is a schematic diagram of the weighing body of an online weighing device for a drying test bench provided by the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the tray in an online weighing device for a drying test bench provided by the present invention;

[0039] Figure 5 This is a schematic diagram of the sealing ring of an online weighing device for a drying test bench provided by the present invention;

[0040] Figure 6 This is a schematic diagram of the weighing ring structure of an online weighing device for a drying test bench provided by the present invention;

[0041] Figure 7 This is a schematic diagram of the base of an online weighing device for a drying test bench provided by the present invention;

[0042] Figure 8 This is a flowchart of an online weighing method for a drying test bench provided by the present invention;

[0043] Figure 9 This is a logic block diagram of the components of an online weighing system for a drying test bench provided by the present invention.

[0044] In the picture:

[0045] 1-Weighing body; 101-Pallet; 102-Sealing ring; 103-Weighing ring; 104-Weighing sensor; 105-Base; 2-Outer shell; 3-Bracket; 4-Quick-connect valve. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0047] In the description of this invention, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are used only for the convenience of describing this invention 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 invention. It should also be understood that, in the context, when referring to an element or feature being located "upper," "lower," "left," or "right" of one or more other elements, it can not only be fixed "upper," "lower," "left," or "right" of one or more other elements, but can also be indirectly fixed "upper," "lower," "left," or "right" of one or more other elements through intermediate elements.

[0048] Unless otherwise specified or indicated, the terms "connection," "setup," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0049] according to Figure 1 , 2As shown in Figures 3, 4, 5, 6, and 7, an online weighing device for a drying test bench includes a tray 101, a sealing ring 102, a weighing ring 103, a weighing sensor 104, a base 105, a housing 2, a bracket 3, and a quick-connect valve 4. The central axes of the tray 101, the sealing ring 102, the weighing ring 103, and the base 105 coincide. The weighing body 1 includes the tray 101, the sealing ring 102, the weighing ring 103, the weighing sensor 104, and the base 105.

[0050] Tray 101 is a material holding container located at the top of the device. Tray 101 is formed by connecting two hollow cylindrical structures of different diameters at one end. The inner diameter of the upper hollow cylinder is the same as the inner diameter of the main pipe of the drying test bench connected to the online weighing device described in this invention. The inner diameter of the lower hollow cylinder is 20-60 mm larger than that of the upper hollow cylinder. A circular connecting piece is provided between the two hollow cylindrical structures. The inner diameter of the circular connecting piece is equal to the outer diameter of the upper hollow cylinder, and the outer diameter of the circular connecting piece is equal to the outer diameter of the lower hollow cylinder. The central axis of the circular connecting piece is aligned with... Two hollow cylindrical structures have coinciding central axes connected by a circular ring connector. The circular ring connector has a certain number of threaded holes spaced along the circumference for fixing sieve plates with different sieve apertures. The sieve plates are circular, and their diameter is the same as the inner diameter of the upper hollow cylinder. During thin-layer drying tests, the sieve apertures are selected according to the different materials to be dried. Different sieve apertures are selected according to the size of the material to be tested to ensure that the material to be tested does not fall through the sieve holes. The bottom of the lower cylindrical structure is in contact with the weighing ring 103 and normally sits vertically on the weighing ring 103.

[0051] The sealing ring 102 is made of silicone and is located in the double-eared groove of the raised part of the base 105. It contacts and separates from the inner wall of the cylindrical structure at the bottom of the tray 101 through gas inflation and deflation. The sealing ring 102 is a square hollow ring structure. In the uninflated state, the inner diameter of the sealing ring 102 is 0-2 mm larger than the inner diameter of the double-eared groove of the base 105, and the outer diameter of the sealing ring 102 is 0-2 mm smaller than the outer diameter of the double-eared groove. In the uninflated state, the sealing ring is completely embedded in the double-eared groove. In the inflated state (when the air pressure inside the sealing ring reaches 1 Pa), the circumference of the sealing ring 102 expands outward, and the outer wall of the sealing ring 102 protrudes outward from the outer edge of the double-eared groove by a maximum of 3-4 mm, pressing against the inner wall of the lower part of the tray 101 to form a closed space. A flexible tube is provided on the lower surface of the sealing ring 102 to allow gas to enter and exit.

[0052] The inner diameter of the weighing ring 103 is 0-5mm larger than the outer diameter of the double-ear groove of the base 105, and its outer diameter is 3-20mm larger than the outer diameter of the hollow cylinder at the bottom of the tray 101. It has a diameter marking ring with the same diameter as the outer diameter of the hollow cylinder at the bottom of the tray 101, used to indicate the placement position of the tray 101. There are threaded holes spaced around its bottom circumference for threaded connection with the load cell 104. The central axis of the weighing ring 103 coincides with the central axis of the tray 101, and the bottom of the weighing ring 103 is fixed to the load cell 104. The diameter marking ring is used for manual adjustment of the tray placement accuracy and to reduce interference with the load cell when the sealing ring is in operation.

[0053] The load cell 104 is a cantilever beam load cell, which is symmetrically mounted on the upper surface of the square flange of the base 105 in a 360° circle (at 90° intervals), and the weighing force surface is fixed to the lower part of the weighing ring 103.

[0054] The lower part of the base 105 is a square flange, and multiple sensor bosses are evenly arranged around the central axis of the base. The lower surface of the flange is connected to the main body of the drying test bench, and the upper surface of the flange provides support for the weighing sensor 104 through the sensor bosses.

[0055] The online weighing device provided by this invention is one of the core components of a drying test bench. The base 105 of the online weighing device is connected to the main pipe (circular) of the drying test bench and is vertically installed on the main pipe. A main air valve for the drying test bench is installed on the main pipe, and the main air valve has two states: open and closed. The air valve adjustment module of the online weighing device is connected to the main air valve of the test bench to control its opening and closing.

[0056] The base 105 consists of two parts: an upper cylindrical part and a lower square flange. The upper cylindrical part has a circular through-hole in the center, the diameter of which is equal to the diameter of the ventilation duct of the main body of the drying test bench. The top of the cylinder has a cylindrical protrusion with an outer diameter 10-40mm larger than the inner diameter and a width of 10-20mm. There is a groove in the center of the protrusion along its width, with a width of 6-16mm and a depth of 4-15mm, for installing the sealing ring 102. The side length of the square flange of the lower part of the base 105 is 40-200mm larger than the outer diameter of the upper cylindrical part. The bottom of the base 105 has a fixing groove with a diameter 2-4mm larger than the outer diameter of the connecting flange of the main body of the drying test bench and a depth of 2mm, for connecting the main body of the drying test bench. The lower cylindrical structure of the tray 101 is nested outside the cylindrical protrusion above the base 105. The upper edge of the cylindrical protrusion above the base 105 is 2-8mm away from the lower surface of the circular connector of the tray 1.

[0057] The outer casing 2 is a protective cover with a square structure. The side length of the inner square hole is equal to the side length of the square flange of the lower part of the base 105. A through hole is provided inside, the diameter of which is larger than the outer diameter of the cylinder of the lower part of the tray 101 but smaller than the outer diameter of the weighing ring 103. Ventilation holes are provided on the outer surface of the outer casing 2 to facilitate airflow and prevent airflow from affecting the weighing sensor 104. The outer casing 2 is nested on the outside of the base 105.

[0058] The bracket 3 is inverted U-shaped, with the upper part fixed to the lower surface of the base 105, and the lower part providing mounting holes for the quick-connect valve.

[0059] The quick-connect valve 4 is an L-shaped quick-plug valve that connects the sealing ring 102 hose and the outer pipe by plugging and unplugging.

[0060] according to Figure 9 As shown, an online weighing system for a drying test bench is used to control the weighing device and process data for an online weighing device for a drying test bench. It includes a CPU module, a timing module, a weight adjustment module, an air valve adjustment module, a storage module, and a display module.

[0061] The CPU module is connected to the timing module, weight adjustment module, air valve adjustment module, storage module, touch LCD display device and interface. The CPU module is used to determine the moisture content of the sample based on the weight data before and after the test. The CPU module uses an STM32F103C8T6 chip and mainly realizes the control of each module and the processing of weight acquisition data.

[0062] The timing module is used to realize timing control during the drying test. It mainly uses the DS1302 clock chip to realize functions such as time output and time calibration, so as to meet the timing needs of the test.

[0063] The weight adjustment module is connected to multiple weighing sensors 104 to collect sample weight data before and after the drying test and upload it to the CPU module. The weight adjustment module is a 4-channel parallel independent conditioning module. The CPU module controls the on / off of the main air valve and sealing ring air valve of the drying test bench through the air valve adjustment module to achieve the drying of the sample in the drying test and the sealing between the tray 101 and the base 105 holding the sample during the online weighing process. The main component is a 24-bit AD conversion chip HX711 to realize the real-time acquisition of signals from the four weighing sensors 104.

[0064] The air valve adjustment module is connected to quick-connect valve 4 and the main air valve of the drying test bench. The air valve adjustment module is a 24V electrically controlled regulating valve, which includes the main air valve of the drying test bench and the sealing ring air valve. The air valve is turned on and off by digital signals 1 and 0.

[0065] Touchscreen LCD displays primarily enable data interaction and measurement result display.

[0066] The interface mainly includes communication interfaces (RS485, USB, etc.) and power interfaces (24V), which are used to provide communication connection and power supply for an online weighing system for a drying test bench.

[0067] The display module includes a touch LCD display device and an interface, which are connected to the CPU module and the weight adjustment module. It is used to display the variety name, weight, and moisture content of the material to be dried in the test, as well as the moisture content of each stage of the test. The display module can be used to set the time interval for weighing the material during the drying test and the moisture content stop threshold of the material.

[0068] The storage module is connected to the CPU module and is used to store experimental data to provide reference data for subsequent experiments.

[0069] according to Figure 8 As shown, an online weighing method for a drying test bench, used in the aforementioned online weighing device and system for a drying test bench, specifically includes the following steps:

[0070] Step 1: Select the type of material to be dried through the display module, input the material name, initial moisture content, and set the weighing time interval, target moisture content, and safe moisture content threshold. The initial moisture content is measured by a dedicated moisture content measuring instrument before the test.

[0071] The target moisture content is the target value for the material moisture content in the thin-layer drying test. The safe moisture content threshold is the allowable range of difference between the material moisture content and the target moisture content. The target moisture content is generally the safe storage moisture content for grains, which varies for different materials. The safe moisture content threshold is the difference between the measured value and the target moisture content, and can be set by the user, with a preferred difference of 0.1%. The standard weighing interval is 10-15 minutes, and the test duration is 5-6 hours. The experimenter can select the weighing interval according to the size of the material to be dried. Taking thin-layer drying tests of corn and wheat as examples, the weighing interval for wheat is 10 minutes, and the weighing interval for corn is 15 minutes.

[0072] Step 2: Remove the tray 101 from the online weighing device, put in a certain amount of material, gently shake the tray 1, and flatten the surface of the material, with the material height lower than the upper edge of the tray 101.

[0073] The tray 101 containing the material is gently placed in the online weighing device, with the lower outer edge of the tray 101 aligning with the diameter marking ring of the weighing ring 103. The weight adjustment module detects the pressure signal output by the material through the weighing sensor 104. After the pressure signal stabilizes without significant fluctuations (1 second), the weight adjustment module determines whether the pressure signals of all weighing sensors 104 are consistent. By checking whether the signals of the weighing sensors 104 are consistent, the module determines whether the material is evenly spread in the tray 101. If the weight adjustment module determines that the pressure signals of all weighing sensors 104 are inconsistent, it indicates that the material is in an abnormal state in the tray 101, meaning that the material is not evenly spread in the tray 101. The tray 101 needs to be removed again to adjust the material's state before weighing again.

[0074] If the weight adjustment module determines that the pressure signals of all weighing sensors 104 are consistent, it assumes that the weight change of pallet 101 is normal, and then calculates the initial weight of the material. The initial weight of the material is the total weight of pallet 101 and the material minus the total weight of pallet 101 itself (known), and the initial weight of the material is recorded.

[0075] Step 3: Open the main air valve and sealing ring 102 air valve of the drying test bench through the air valve adjustment module. First, open the sealing ring 102 air valve to inflate it until it expands to the inflated state. Then, according to the input parameters, open the main air valve of the drying test bench to start the drying operation. The drying gas enters the weighing device through the main pipeline of the test bench and is discharged through the sieve holes of the sieve plate connected to the tray 101. Record the test time.

[0076] Step 4: The timing module determines whether the time has elapsed based on the set time interval. If the time has not elapsed, the operation continues. If the time has elapsed, the main air valve and the sealing ring air valve of the drying test bench are closed in succession.

[0077] If the pressure signals of all weighing sensors 104 do not fluctuate significantly and tend to stabilize (default 1s), that is, after the weight change of pallet 101 is normal, the material is weighed online to obtain the current material weight.

[0078] Step 5: Calculate the current moisture content of the material based on the original weight of the material and the current weight of the material after the stage test. Current moisture content of the material = [initial moisture content × initial weight of the material - (initial weight of the material - current weight of the material)] × 100% / current weight of the material. Then, determine the current moisture content of the material. If the current moisture content of the material is close to the target moisture content and the error is less than the safe moisture content threshold, the material drying is completed and the test ends. Otherwise, repeat steps 3 to 5.

[0079] Traditional weighing methods take approximately 3-5 minutes per weighing, while this method takes less than 10 seconds per weighing. In addition, high-temperature airflow and metal often cause injury to test personnel. This method greatly improves work efficiency and automation.

[0080] The advantages of this invention are that, compared with existing technologies, it has a simple structure, is easy to operate, and can greatly improve experimental efficiency. It mainly employs a combination of a weighing sensor and an inflatable sealing ring, utilizing the principle of their alternating cyclic operation to develop online material weighing technology and design an online precision weighing device. Through the weighing sensor, it achieves material uniformity determination and in-situ, online, precise, and rapid weight measurement.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the protection scope of the claims of the present invention.

Claims

1. An online weighing method for a thin-layer drying test bench, based on an online weighing device for a thin-layer drying test bench, characterized in that: Includes the following steps: Step 1: Select the type of material to be dried, enter the material name, initial moisture content, and set the weighing time interval, target moisture content, and safe moisture content threshold for the material. Step 2: Place the material to be dried in the tray (101), place the tray (101) with the material in the online weighing device, and after confirming that there is no abnormality in the weight change of the tray (101) through the weight adjustment module, record the initial weight of the material. Step 3: Open the main air valve and sealing ring (102) air valve of the drying test bench through the air valve adjustment module, so that the sealing ring (102) expands to the inflation state, then open the main air valve of the drying test bench to start the drying operation and record the test time. Step 4: When the test time reaches the weighing interval, close the main air valve and the sealing ring (102) air valve of the drying test bench. If there is no abnormal change in the weight of the tray (101), the material is weighed online to obtain the current material weight. Step 5: Calculate the current moisture content of the material based on the initial weight of the material and the current weight of the material after the stage test. If the current moisture content of the material is close to the target moisture content and the error is less than the safe moisture content threshold, the material drying is completed and the test ends. Otherwise, repeat steps 3 to 5. The online weighing device for the thin-layer drying test bench includes a tray (101), a sealing ring (102), a weighing ring (103), a weighing sensor (104), and a base (105). A hollow cylindrical structure is provided in the middle of the base (105), and the base (105) is set on the drying test bench and connected to the main pipe of the drying test bench; The weighing ring (103) is sleeved on the outer edge of the hollow cylindrical structure of the base (105) and placed on the upper end of a plurality of weighing sensors (104) that are evenly arranged on the platform of the base (105) around the hollow cylindrical structure. The tray (101) is nested on the outer edge of the hollow cylindrical structure of the base (105) and placed on the upper end of the weighing ring (103). When the tray (101) is nested on the outer edge of the hollow cylindrical structure, a sealing ring (102) is provided between the lower end of the tray (101) and the outer edge of the hollow cylindrical structure. The central axes of the tray (101), sealing ring (102), weighing ring (103), and base (105) coincide.

2. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that: The tray (101) includes two hollow cylindrical structures with different diameters. The two hollow cylindrical structures with different diameters are connected at one end, and a circular connecting piece is provided at the connection point. The circular connecting piece is perpendicular to the central axis of the two hollow cylindrical structures, and the circular connecting piece matches the cross-section of the hollow cylindrical structure with the larger diameter. The annular connector has a certain number of threaded holes spaced along the circumference, and the annular connector is connected to the screen plates with different screen hole diameters through the threaded holes.

3. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that: The hollow cylindrical structure of the base (105) is provided with a double-eared groove for nesting the sealing ring (102) on its outer periphery; the sealing ring (102) is a hollow ring structure, which is connected to one end of the hose, and the other end of the hose is connected to a quick-connect valve (4). In the uninflated state, the sealing ring (102) is completely embedded in the double ear groove. In the inflated state, it is in the working state. In the inflated state, the sealing ring (102) expands outward around its circumference, and the outer wall of the sealing ring (102) protrudes from the outer edge of the double ear groove, which is squeezed against the inner wall of the tray (101) nested in the outer edge of the hollow ring structure to form a closed space.

4. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that: A diameter marking ring is provided on the side where the weighing ring (103) is connected to the tray (101).

5. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that: The cylindrical structure of the base (105) is nested with the tray (101). The base (105) is connected to the main body of the drying test bench. A fixed circular groove is provided on the side of the base (105) connected to the main body of the drying test bench. The base (105) is connected to the main body of the drying test bench by a bracket (3). The bracket (3) is inverted U-shaped. The upper end of the bracket (3) is fixed to the lower surface of the base (105), and the lower end provides an installation hole for the quick-connect valve (4). The main air valve of the drying test bench is installed on the main pipeline.

6. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that: The base (105) is nested with a shell (2) on the outside. The shell (2) has a through hole inside and a vent hole on the outer surface of the shell (2).

7. The online weighing method for a thin-layer drying test bench according to claim 1, characterized in that, The method for determining whether the weight change of pallet (101) is normal is as follows: When the outer edge of one end of the tray (101) contacts the diameter marking ring on the weighing ring (103), the weighing sensor (104) senses the material and outputs a pressure signal to the weight adjustment module to trigger detection. After the weight adjustment module detects that the pressure signal has no obvious fluctuation and tends to be stable, the weight adjustment module judges whether the signals of all weighing sensors (104) are consistent. If the pressure signals of all weighing sensors (104) are inconsistent, it indicates that the material in the tray (101) is in an abnormal state and the tray (101) needs to be removed again to adjust the material state and weighed again. If the pressure signals of all weighing sensors (104) are consistent, it is determined that the weight change of the tray (101) is normal.

8. An online weighing system for a thin-layer drying test bench based on the online weighing method of any one of claims 1-7, comprising a CPU module, a timing module, a weight adjustment module, and an air valve adjustment module, characterized in that: The CPU module is connected to the timing module, weight adjustment module, and air valve adjustment module. The valve adjustment module is connected to the quick-connect valve (4) and the main valve of the drying test bench. The CPU module controls the opening and closing of the main valve and the sealing ring valve of the drying test bench through the valve adjustment module, so as to realize the drying of the sample in the drying test and the sealing between the tray (101) and the base (105) holding the sample during the online weighing process. The CPU module is used to determine the moisture content of the sample based on the weight data before and after the test. The timing module is used to control the timing during the drying test; The weight adjustment module is connected to multiple weighing sensors to collect sample weight data before and after the drying test and upload it to the CPU module.

9. The online weighing system for a thin-layer drying test bench according to claim 8, characterized in that: The online weighing system also includes a display module and a storage module; The display module is connected to the CPU module and the weight adjustment module. It is used to display the name of the material to be dried, its weight, and the moisture content at each stage of the test. The display module can also be used to set the time interval for weighing the material during the drying test and the stop threshold for the moisture content of the material. The storage module is connected to the CPU module and is used to store parameter settings and experimental data during operation, providing reference data for subsequent experiments.

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