A device and method for measuring the specific surface area of a granular material

Abstract

The application discloses a kind of granular material specific surface area measuring device and method, wherein measuring device includes measuring barrel assembly, air supply component and controller system;Measuring barrel assembly includes mainframe, storage barrel, butterfly valve pipe and inlet pipe;Double-disc butterfly valve assembly is equipped in butterfly valve pipe, when motor operates, active rotation drives first disc to synchronous deflection, simultaneously, driving gear engages transmission driven gear reverse rotation, in turn, driven shaft and second disc synchronous reverse deflection are driven, realize the closing and conduction of butterfly valve pipe internal material passage;Air supply component includes fan frame and fan, and fan is communicated with lower portion in storage barrel by air pipe;Controller system includes sensing unit, data processing module and display module;Sensing unit includes infrared range finder, vortex flowmeter and differential pressure gauge.The application can detect static granular material specific surface area, and also can detect material specific surface under flow state, solve the pain point problem that traditional detection is disjointed with agricultural engineering application.

Description

Technical Field

[0001] This invention relates to the field of agricultural material property testing technology, specifically to a device and method for measuring the specific surface area of ​​particulate materials. Background Technology

[0002] Specific surface area is related to many factors such as material shape, filling method, material size, moisture content, placement time, and movement state. It is an important characteristic parameter that must be used for the optimized design of drying system and the realization of intelligent process control. It directly affects energy transfer, moisture migration, ventilation resistance of drying layer, drying efficiency and quality during the drying process.

[0003] In actual drying processes, many materials are in a fluid state, which further increases the difficulty of measuring the specific surface area of ​​particulate materials. The industry has long lacked highly adaptable dedicated measurement methods and devices. Existing testing methods mostly use general-purpose powder testing instruments from the chemical and building materials industries. These devices are designed for inorganic hard mineral particles, and their theoretical models, sample pretreatment procedures, and testing standards are not optimized for porous, fibrous, high-moisture, and irregularly shaped agricultural biomass. The test data deviates significantly from the effective external surface area required for agricultural machinery engineering, making it difficult to directly use for agricultural machinery structure simulation and process parameter calculation, thus hindering the development of basic research on agricultural materials and intelligent processing equipment.

[0004] Currently, commonly used specific surface area measuring instruments mainly include four categories: BET nitrogen adsorption analyzer, Blaine air permeability specific surface area analyzer, sieving geometric measurement device, and general two-dimensional image particle size analyzer. Each of them has the following technical defects:

[0005] 1. BET nitrogen adsorption analyzers require high-temperature vacuum degassing to remove moisture from materials. The high-temperature environment easily causes crop fibers to shrink, cell wall micropores to collapse, and lignocellulosic organic matter to char, damaging the original surface structure of the material. Low-temperature degassing cannot completely remove bound water, which clogs fiber pores, resulting in lower test results. Furthermore, the value measured by this equipment is the total specific surface area including micropores. Micropores do not participate in mechanical actions such as material friction, collision, or transport, which does not match the mechanical specific surface area concept required in engineering. A single test takes 1-3 hours and requires continuous consumption of liquid nitrogen, resulting in high equipment costs and making it unsuitable for rapid testing of large batches of samples.

[0006] 2. The Blaine air permeability surface area meter calculates the specific surface area by relying on the pressure difference of gas passing through the powder material layer. It is only suitable for homogeneous hard mineral powder. However, agricultural fibrous materials are loose, elastic, and changes in moisture content will change the porosity of the material layer. Even slight differences in compaction can cause drastic fluctuations in air permeability resistance. The test has poor repeatability and large systematic error, and it is rarely used for biomass material testing.

[0007] 3. The geometric calculation method of sieving and manual calipers assumes that the particles are standard spheres. However, crops are mostly long fibers, thin sheets, or ellipsoidal irregular structures. The spherical assumption differs greatly from the actual shape and cannot take into account the extra contact area caused by surface wrinkles and burrs. It can only make a rough estimate, and the measurement accuracy cannot meet the standards of scientific research experiments.

[0008] 4. Traditional commercial machine vision particle size analyzers lack dedicated lighting systems and adhesion segmentation algorithms for crops. Fine materials such as straw and bran are prone to stacking and obscuring contours, and shadows and fiber intersections can cause edge recognition failures. The equipment is not equipped with moisture content and material morphology correction models, resulting in high dispersion of detection data for different types of crops and insufficient versatility.

[0009] In summary, existing testing equipment suffers from problems such as poor material compatibility, easily damaging samples during pretreatment, a disconnect between testing indicators and engineering requirements, low testing efficiency, and poor measurement stability. The agricultural engineering field lacks a dedicated testing device specifically designed for crop biomass that can achieve non-destructive pretreatment and accurately measure the effective mechanical surface area. Furthermore, existing surface area measurement equipment and methods are all based on static steady-state conditions and cannot be used for measuring surface area under dynamic conditions. When analyzing dynamic processes, this often leads to significant discrepancies between calculated results and actual conditions, highlighting the lack of devices and methods for measuring the surface area of ​​particulate materials in flowing states. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device for measuring the specific surface area of ​​particulate materials.

[0011] Technical solution of the present invention:

[0012] A device for measuring the specific surface area of ​​particulate materials includes a measuring barrel assembly, an air supply assembly, and a controller system;

[0013] The measuring barrel assembly includes a main frame, a detachably connected storage barrel, a butterfly valve pipe, and an inlet pipe; the storage barrel is mounted on the main frame; the butterfly valve pipe is equipped with a double-disc butterfly valve assembly, which includes a first disc, a second disc, a drive shaft, a driven shaft, a drive gear, a driven gear, and a motor;

[0014] The motor is mounted on the storage hopper via a motor mounting bracket. The output end of the motor is connected to the drive shaft. The drive shaft and the driven shaft extend from the outside of the butterfly valve tube through corresponding shaft holes into the inside of the butterfly valve tube. The axes of the drive shaft and the driven shaft are parallel to each other and are on the same plane.

[0015] The drive shaft is equipped with a drive gear, and the driven shaft is equipped with a driven gear that meshes with the drive gear. The drive shaft and the driven shaft are respectively equipped with a first disc and a second disc. The first disc and the second disc are evenly distributed with vent holes. The diameter of the vent holes is smaller than the particle size of the granular material. The edge contours of the first disc and the second disc are adapted to the inner wall of the butterfly valve tube. When the motor is running, the drive shaft rotates and drives the first disc to deflect synchronously. At the same time, the drive gear meshes with and drives the driven gear to rotate in the opposite direction, thereby driving the driven shaft and the second disc to deflect synchronously in the opposite direction, realizing the closure and opening of the material channel inside the butterfly valve tube.

[0016] The air supply assembly includes a fan frame and a fan. The fan is mounted on one side of the measuring bucket assembly via the fan frame, and the fan is connected to the lower part of the storage bucket via an air duct.

[0017] The controller system includes a sensing unit, a data processing module, and a display module;

[0018] The sensing unit includes an infrared rangefinder, a vortex flow meter, and a differential pressure gauge;

[0019] The infrared rangefinder is installed above the feed pipe to measure the calibrated distance h1 from the horizontal reference plane to the feed inlet end face when the butterfly disc is closed in the butterfly valve pipe, and the distance h2 from the top of the granular material to the feed inlet end face; the vortex flow meter is installed on the air duct to measure the airflow rate; the differential pressure gauge is installed on the main frame, and the two pressure taps of the differential pressure gauge are respectively connected to two differential pressure gauge pressure taps on the side wall of the butterfly valve pipe through the differential pressure gauge tube to measure the airflow differential pressure of the material layer. One differential pressure gauge pressure tap is parallel to the upper surface of the disc, and the other differential pressure gauge pressure tap is at a preset height above the disc. The height distance between the two differential pressure gauge pressure taps is the preset thickness of the material layer.

[0020] The data processing module is used to calculate the difference between h1 and h2 to obtain the real-time thickness of the particulate material layer. When the real-time thickness of the material layer reaches the preset thickness of the material layer, the preset thickness of the material layer, the airflow rate, and the airflow pressure difference are substituted into the preset formula to calculate the specific surface area, and the calculation result is transmitted to the display module.

[0021] Furthermore, the preset formula is as follows:

[0022] (1)

[0023] (2)

[0024] In the formula: K is the permeability of the material layer; q is the airflow rate through the material layer; ρ is the pneumatic viscosity; A is the cross-sectional area of ​​the particulate material inside the butterfly valve tube; P is the airflow pressure difference of the material layer; L is the filling length of the particulate material in the direction of fluid flow, i.e. the preset thickness of the material layer. is the specific surface area of ​​the particulate material; is the porosity of the particulate material, and is the preset calibration parameter for the corresponding material.

[0025] Furthermore, the controller system also includes a control module, with the fan and motor connected to the control module respectively.

[0026] Furthermore, the adjacent mating ends of the storage hopper, butterfly valve pipe, and feed pipe are connected by threaded pairs to achieve a detachable and sealed connection.

[0027] Furthermore, the upper inner part of the storage hopper is provided with a first internal thread, and the outer wall of the lower part of the butterfly valve tube is provided with a first external thread that mates with the first internal thread. The upper inner part of the butterfly valve tube is provided with a second internal thread, and the outer wall of the lower part of the feed pipe is provided with a second external thread that mates with the second internal thread.

[0028] Furthermore, the bottom of the storage bin is provided with a discharge end cap, the lower inner part of the storage bin is provided with a third internal thread, and the upper outer wall of the discharge end cap is provided with a third external thread that mates with the third internal thread.

[0029] Furthermore, the drive shaft and driven shaft respectively achieve radial rotation support and radial sealing through sealed bearings nested in the inner wall of the shaft hole.

[0030] Furthermore, the end of the differential pressure gauge tube is equipped with a quick-connect fitting, and the butterfly valve tube is equipped with a differential pressure gauge tapping interface that corresponds to the quick-connect fitting. The differential pressure gauge tube is sealed and fixed to the differential pressure gauge tapping interface through the quick-connect fitting.

[0031] The present invention also provides a method for measuring the specific surface area of ​​static particulate materials, using the above-mentioned measuring device, comprising the following steps:

[0032] S1. Fill the butterfly valve tube with the particle material to be tested to the preset thickness of the material layer.

[0033] S2. Start the fan and collect the flow rate: After the material is loaded, start the fan. The airflow generated by the fan is delivered to the inside of the storage tank through the air duct. The instantaneous volumetric flow rate of the airflow is measured by the vortex flow meter installed on the air duct section.

[0034] S3. Forming a uniform upward airflow: After the airflow enters the storage tank, it collides with the inner wall of the tank and naturally turns to form a uniform upward airflow. This upward airflow flows smoothly through the granular material layer loaded on the double discs in the butterfly valve tube, forming a stable airflow pressure difference between the upstream and downstream ends of the material layer.

[0035] S4, Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top of the feed pipe (2), forming a complete airflow measurement circuit.

[0036] S5. Specific surface area calculation output: The data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, air flow rate, and air pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output.

[0037] S6. Unloading and Resetting: After all measurement data has been collected, start the motor. The motor drives the drive gear on the drive shaft to rotate through the output shaft. The gear meshing drives the driven gear on the driven shaft to rotate synchronously in the opposite direction, thereby driving the first and second discs to flip down synchronously to open the channel. The material that has been measured falls steadily into the storage bucket by its own weight. After all the material has fallen, simply twist the unloading end cap at the bottom of the storage bucket to quickly remove it, completing the unloading without residue, and preparing for the measurement of the next set of samples.

[0038] The present invention also provides a method for measuring the specific surface area of ​​flowing particulate materials, using the above-mentioned measuring device, comprising the following steps:

[0039] S1. Fill the butterfly valve tube with the granular material to be tested until the feed tube is full. The infrared rangefinder measures the calibrated distance h1 from the horizontal reference plane to the feed port end face when the butterfly plate is closed in the butterfly valve tube, and the distance h2 from the top of the granular material to the feed port end face. The data processing module automatically calculates the difference between h1 and h2 to obtain the real-time thickness of the granular material layer.

[0040] S2. Start the motor. The motor drives the drive gear on the drive shaft to rotate through the output shaft. The gear meshing drives the driven gear on the driven shaft to rotate synchronously in the opposite direction, thereby driving the first and second discs to flip downwards synchronously to open the channel. At the same time, start the fan and flow acquisition: the airflow generated by the fan is delivered to the inside of the storage tank through the air duct. The instantaneous volumetric flow rate of the airflow is measured by the vortex flow meter installed on the air duct section. After the airflow enters the storage tank, it collides with the inner wall of the tank and naturally turns to form a uniform rising airflow. This rising airflow flows smoothly through the granular material layer in the butterfly valve tube, forming a stable airflow pressure difference between the material layers. The material relies on its own weight and the lift of the airflow to form a dynamic balance and falls into the storage tank at a stable speed.

[0041] S3, Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top of the feed pipe (2), forming a complete airflow measurement circuit.

[0042] S4. Specific surface area calculation output: When the real-time thickness of the particulate material layer reaches the preset thickness of the material layer, the data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, airflow rate, and airflow pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output.

[0043] S5. The measured material falls steadily into the storage bucket under its own weight. After all the material has fallen, simply twist the unloading end cap at the bottom of the storage bucket to quickly remove it, completing the unloading without residue and preparing for the measurement of the next set of samples.

[0044] Beneficial effects:

[0045] 1. This invention is custom-designed for the characteristics of agricultural biomass materials, avoiding the compatibility defects of traditional mineral powder testing equipment. It eliminates the need for destructive pretreatment processes such as high-temperature vacuum degassing and liquid nitrogen consumption, and completes the testing process entirely under normal temperature and pressure. It can completely preserve the original structure and moisture content of the tested materials such as straw fiber and grain. It can detect the specific surface area of ​​particulate materials under static steady-state conditions, as well as accurately measure the specific surface area of ​​materials under flowing conditions. It matches the engineering needs of agricultural machinery equipment design and process optimization, and solves the pain point of the disconnect between traditional testing and agricultural engineering applications.

[0046] 2. This invention uses a double-disc butterfly valve assembly as a material support carrier. When the two discs are closed, they can form a flat and stable material support platform. The uniform air vents on the discs will not block the airflow from passing through the material layer evenly, and there is no need to add an extra screen component that is prone to clogging. This avoids the problem of drastic fluctuations in air permeability resistance caused by screen clogging and uneven material layer compaction in traditional Blaine air permeability meters. The repeatability of detection for loose fibrous, high moisture content, and irregularly shaped agricultural materials is greatly improved, and the measurement system error can be controlled within the allowable range of industry standards.

[0047] 3. This invention utilizes an infrared rangefinder to achieve non-contact automatic acquisition of material accumulation height, eliminating the need for manual reading. Combined with a differential pressure acquisition structure that directly taps pressure through a butterfly valve pipe, it eliminates signal lag and pressure loss caused by long-distance pressure tapping pipelines. In conjunction with a vortex flow meter to collect dynamic airflow in real time, the data from these three types of sensors are simultaneously input into the data processing module to automatically complete the specific surface area calculation. The entire process detection time for a single sample is significantly reduced, meeting the rapid detection needs of large batches of samples in agricultural research and engineering fields.

[0048] 4. The measuring bucket assembly adopts a threaded, detachable, and sealed connection structure. The storage bucket, butterfly valve pipe, and feed pipe can be quickly disassembled, making it convenient for operators to thoroughly clean residual fiber debris from different samples and avoiding cross-contamination between different batches of crop samples. The bottom threaded discharge end cap can be directly screwed off, ensuring smooth and residue-free discharge and reducing the difficulty of daily equipment maintenance.

[0049] 5. The integrated control module of the controller system can automatically complete the entire process of fan start-up and shutdown, butterfly valve opening and closing, data acquisition, and unloading reset according to the preset sequence, without the need for manual intervention. The equipment operation threshold is greatly reduced. It is suitable for high-precision testing scenarios in laboratories of universities and research institutes, and can also be directly deployed in the field rapid testing stations of agricultural machinery manufacturing enterprises and straw processing bases, filling the industry gap of special specific surface area testing equipment for crop biomass. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the structure of the present invention;

[0051] Figure 2 This is a schematic diagram of the measuring barrel assembly in this invention;

[0052] Figure 3 This is a schematic diagram of the structure of the dual-disc butterfly valve assembly in this invention;

[0053] In the diagram: 1. Infrared rangefinder; 2. Feed pipe; 3. Butterfly valve pipe; 4. First disc; 5. Drive shaft; 6. Driven shaft; 7. Main frame; 8. Storage hopper; 9. Discharge end cover; 10. Controller system; 11. Fan frame; 12. Fan; 13. Air duct; 14. Second disc; 15. Vortex flow meter; 16. Differential pressure gauge pipe; 17. Driven gear; 18. Motor mounting base; 19. Motor; 20. Drive gear; 21. Quick connector; 22. Differential pressure gauge; 23. Differential pressure gauge pressure tap. Detailed Implementation

[0054] The present invention can be further described through the following embodiments; however, the scope of the invention is not limited to the following embodiments. It should be understood that the embodiments described herein are disclosed by way of illustration only, and the invention is not intended to limit its scope to the details of the construction and arrangement of the components described below or illustrated in the figures. Furthermore, in describing preferred embodiments, specific terminology will be used for clarity. It should be understood that each specific term includes all technical equivalents that operate in a similar manner to achieve a similar purpose.

[0055] Example 1: As Figures 1 to 3 The device shown is a particulate material specific surface area measuring device, including a measuring barrel assembly, an air supply assembly and a controller system 10;

[0056] The measuring barrel assembly includes a main frame 7, a detachably connected storage barrel 8, a butterfly valve pipe 3, and an inlet pipe 2; the storage barrel 8 is mounted on the main frame 7; the butterfly valve pipe 3 is equipped with a double disc butterfly valve assembly, which includes a first disc 4, a second disc 14, a drive shaft 5, a driven shaft 6, a drive gear 20, a driven gear 17, and a motor 19;

[0057] The motor 19 is mounted on the storage hopper 8 via the motor mounting base 18. The output end of the motor 19 is connected to the drive shaft 5. The drive shaft 5 and the driven shaft 6 extend from the outside of the butterfly valve tube 3 through corresponding shaft holes into the inside of the butterfly valve tube 3. The axes of the drive shaft 5 and the driven shaft 6 are parallel to each other and are on the same plane.

[0058] A drive gear 20 is mounted on the drive shaft 5, and a driven gear 17 meshing with the drive gear 20 is mounted on the driven shaft 6. A first disc 4 and a second disc 14 are respectively mounted on the drive shaft 5 and driven shaft 6. Ventilation holes are evenly distributed on both the first disc 4 and the second disc 14. The diameter of the ventilation holes is smaller than the particle size of the granular material. These ventilation holes can stably support the granular material in a closed state, and also allow airflow to pass evenly through the discs and directly act on the material layer, avoiding the airflow deviation and eddy current problems caused by the complete closure of traditional butterfly valves, thus significantly improving the stability of differential pressure acquisition. The edge contours of the first disc 4 and the second disc 14... Adapted to the inner wall of the butterfly valve tube, when the motor 19 runs, the drive shaft 5 rotates, driving the first disc 4 to deflect synchronously. At the same time, the drive gear 20 meshes with the driven gear 17 to rotate in the opposite direction, thereby driving the driven shaft 6 and the second disc 14 to deflect synchronously in the opposite direction, realizing the closure and opening of the material channel inside the butterfly valve tube. Through the butterfly valve structure design of double discs in reverse linkage, a stable material support platform can be formed when the discs are closed. There is no need to install additional auxiliary support components such as screens, allowing the granular material after measurement to fall completely by its own weight, without jamming or residue throughout the process, greatly simplifying the loading and unloading operation process.

[0059] The air supply assembly includes a fan frame 11 and a fan 12. The fan 12 is mounted on one side of the measuring barrel assembly via the fan frame 11. The fan 12 is connected to the lower part of the storage barrel 8 via an air duct 13.

[0060] The controller system includes a sensing unit, a data processing module, and a display module;

[0061] The sensing unit includes an infrared rangefinder 1, a vortex flow meter 15, and a differential pressure gauge 22;

[0062] An infrared rangefinder 1 is installed above the feed pipe 2 to measure the calibrated distance h1 from the horizontal reference plane to the feed inlet end face when the butterfly disc is closed in the butterfly valve tube, and the distance h2 from the top of the granular material to the feed inlet end face; a vortex flow meter 15 is installed on the air duct 13 to measure the airflow rate; the differential pressure gauge 22 is installed on the main frame 7, and the two pressure taps of the differential pressure gauge 22 are respectively connected to two differential pressure gauge pressure taps 23 on the side wall of the butterfly valve tube 3 through the differential pressure gauge tube 16, for measuring the airflow pressure difference of the material layer. One differential pressure gauge pressure tap 23 is parallel to the upper surface of the disc, and the other differential pressure gauge pressure tap 23 is at a preset height above the disc. The height distance between the two differential pressure gauge pressure taps 23 is the preset thickness of the material layer; by collecting the pressure difference through the two differential pressure gauge pressure taps 23, the airflow pressure difference upstream and downstream of the material layer can be accurately captured; by changing the butterfly valve tube with different pressure tap spacing, the measurement requirements of materials with different thicknesses can be adapted.

[0063] The data processing module is used to calculate the difference between h1 and h2 to obtain the real-time thickness of the particulate material layer. When the real-time thickness of the material layer reaches the preset thickness of the material layer, the preset thickness of the material layer, the airflow rate, and the airflow pressure difference are substituted into the preset formula to calculate the specific surface area, and the calculation result is transmitted to the display module.

[0064] More specifically, the preset formula is as follows:

[0065] (1)

[0066] (2)

[0067] In the formula: K is the permeability of the material layer; q is the airflow rate through the material layer; ρ is the pneumatic viscosity; A is the cross-sectional area of ​​the particulate material inside the butterfly valve tube; P is the airflow pressure difference of the material layer; L is the filling length of the particulate material in the direction of fluid flow, i.e. the preset thickness of the material layer. is the specific surface area of ​​the particulate material; is the porosity of the particulate material, and is the preset calibration parameter for the corresponding material.

[0068] In this embodiment, the controller system also includes a control module, with the fan 12 and motor 19 connected to the control module respectively; it can automatically complete the linkage control of fan start-up and shutdown and butterfly valve opening and closing according to the preset timing logic, and can realize fully automated measurement from loading to data acquisition and unloading reset.

[0069] In this embodiment, the adjacent mating ends of the storage tank 8, the butterfly valve pipe 3, and the feed pipe 2 are connected by threaded pairs to achieve a detachable and sealed connection. Furthermore, the upper inner part of the storage tank 8 is provided with a first internal thread, and the lower outer wall of the butterfly valve pipe 3 is provided with a first external thread that mates with the first internal thread. The upper inner part of the butterfly valve pipe 3 is provided with a second internal thread, and the lower outer wall of the feed pipe 2 is provided with a second external thread that mates with the second internal thread. Furthermore, the bottom of the storage tank 8 is provided with a discharge end cap 9, the lower inner part of the storage tank 8 is provided with a third internal thread, and the upper outer wall of the discharge end cap 9 is provided with a third external thread that mates with the third internal thread. The removable sealing structure of the threaded joints between the adjacent mating ends of the storage tank 8, butterfly valve pipe 3, and feed pipe 2, combined with the first internal and external threads that fit the upper part of the storage tank and the lower part of the butterfly valve pipe, the second internal and external threads that fit the upper part of the butterfly valve pipe and the lower part of the feed pipe, and the third internal and external threads that fit the bottom of the storage tank and the discharge end cap, enables quick alignment, screwing, and locking of each functional pipe section. On the other hand, each pipe section can be independently and quickly disassembled. This facilitates the operator to regularly clean the residual particulate material inside the pipe, avoiding cross-contamination between different batches of samples. It also allows for individual disassembly and replacement of the corresponding pipe section when the butterfly valve assembly becomes stuck or the seals wear out. This effectively reduces the equipment's operation and maintenance costs and disassembly difficulty. At the same time, the discharge end cap connected by the bottom thread can be directly screwed off, achieving rapid and residue-free discharge of the material after measurement, which greatly improves the overall operational efficiency of particulate material specific surface area measurement.

[0070] In this embodiment, the drive shaft 5 and the driven shaft 6 achieve radial rotation support and radial sealing respectively through sealed bearings nested in the inner wall of the shaft hole. By simultaneously providing radial rotation support for the drive shaft and the driven shaft and radial sealing at the shaft gap through the sealed bearings nested in the inner wall of the shaft hole, the transmission accuracy of the synchronous rotation of the two shafts in opposite directions is ensured, and the airflow in the butterfly valve tube is prevented from leaking outward through the shaft hole gap, thus avoiding distortion of the differential pressure measurement data caused by airflow leakage.

[0071] In this embodiment, the end of the differential pressure gauge tube 16 is provided with a quick-connect connector 21, and the butterfly valve tube 3 is provided with a differential pressure gauge tapping interface 23 corresponding to the quick-connect connector 21. The differential pressure gauge tube 16 is sealed and fixed to the differential pressure gauge tapping interface 23 through the quick-connect connector 21. By sealing and fixing the quick-connect connector at the end of the differential pressure gauge tube to the differential pressure gauge tapping interface 23 on the side wall of the butterfly valve tube, direct sampling of the differential pressure of the butterfly valve tube without conversion can be realized, avoiding the problems of air leakage at the tapping port and cumbersome disassembly and assembly, and improving the response speed of differential pressure acquisition and the efficiency of disassembly and maintenance.

[0072] Example 2: The present invention also provides a method for measuring the specific surface area of ​​static particulate materials, using the above-mentioned measuring device, including the following steps:

[0073] S1. Fill the butterfly valve tube 3 with the particle material to be tested to the preset thickness of the material layer.

[0074] S2. Start the fan and collect the flow rate: After the material is loaded, start the fan 12. The airflow generated by the fan 12 is delivered to the inside of the storage tank 8 through the air duct 13. The instantaneous volumetric flow rate of the airflow is measured by the vortex flow meter 15 installed on the section of the air duct 13.

[0075] S3. Forming a uniform upward airflow: After the airflow enters the storage tank 8, it collides with the inner wall of the tank and naturally turns to form a uniform upward airflow. This upward airflow flows smoothly through the granular material layer loaded on the double discs in the butterfly valve pipe 3, forming a stable airflow pressure difference between the upstream and downstream ends of the material layer.

[0076] S4. Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top opening of the feed pipe 2, forming a complete airflow measurement loop.

[0077] S5. Specific surface area calculation output: The data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, air flow rate, and air pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output.

[0078] S6. Unloading and Resetting: After all measurement data has been collected, start motor 19. Motor 19 drives the drive gear 20 on drive shaft 5 to rotate through output shaft. The gear meshing drives the driven gear 17 on driven shaft 6 to rotate synchronously in the opposite direction, thereby driving the first disc 4 and the second disc 14 to rotate downwards synchronously to open the channel. The material that has been measured falls steadily into storage bucket 8 by its own weight. After all the material has fallen, the unloading end cap 9 at the bottom of storage bucket 8 can be screwed on to quickly remove it, completing the unloading without residue, and preparing for the measurement of the next set of samples.

[0079] Example 3: The present invention also provides a method for measuring the specific surface area of ​​flowing particulate materials, using the above-mentioned measuring device, including the following steps:

[0080] S1. Fill the butterfly valve tube 3 with the granular material to be tested until the feed tube 2 is full. The infrared rangefinder 1 measures the calibrated distance h1 from the horizontal reference plane to the feed port end face when the butterfly plate is closed in the butterfly valve tube, and the distance h2 from the top of the granular material to the feed port end face. The data processing module automatically calculates the difference between h1 and h2 to obtain the real-time thickness of the granular material layer.

[0081] S2. Start motor 19. Motor 19 drives the drive gear 20 on drive shaft 5 to rotate through output shaft. The gear meshing drives the driven gear 17 on driven shaft 6 to rotate synchronously in the opposite direction, thereby driving the first disc 4 and the second disc 14 to rotate downward synchronously to open the channel. At the same time, start the fan and flow acquisition: the airflow generated by fan 12 is delivered to the inside of storage tank 8 through air duct 13. The instantaneous volumetric flow rate of the airflow is measured by vortex flow meter 15 installed on the section of air duct 13. After the airflow enters storage tank 8, it collides with the inner wall of the tank and naturally turns to form a uniform rising airflow. This rising airflow flows smoothly through the granular material layer in butterfly valve pipe 3, forming a stable airflow pressure difference between the material layers. The material relies on its own weight and the lift of the airflow to form a dynamic balance and falls into storage tank 8 at a stable speed.

[0082] S3, Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top of the feed pipe (2), forming a complete airflow measurement circuit.

[0083] S4. Specific surface area calculation output: When the real-time thickness of the particulate material layer reaches the preset thickness of the material layer, the data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, airflow rate, and airflow pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output.

[0084] S5. The measured material falls steadily into the storage bucket 8 under its own weight. After all the material has fallen, the unloading end cap 9 at the bottom of the storage bucket 8 can be screwed on to quickly remove it, completing the unloading without residue and preparing for the measurement of the next set of samples.

[0085] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0086] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A device for measuring the specific surface area of ​​particulate materials, characterized in that, Includes a measuring tank assembly, an air supply assembly, and a controller system (10); The measuring barrel assembly includes a main frame (7), a detachably connected storage barrel (8), a butterfly valve pipe (3), and a feed pipe (2); the storage barrel (8) is mounted on the main frame (7); the butterfly valve pipe (3) is equipped with a double-disc butterfly valve assembly, which includes a first disc (4), a second disc (14), a drive shaft (5), a driven shaft (6), a drive gear (20), a driven gear (17), and a motor (19); The motor (19) is mounted on the storage hopper (8) via the motor mounting base (18). The output end of the motor (19) is connected to the drive shaft (5). The drive shaft (5) and the driven shaft (6) extend from the outside of the butterfly valve tube (3) through corresponding shaft holes to the inside of the butterfly valve tube (3). The axes of the drive shaft (5) and the driven shaft (6) are parallel to each other and are on the same plane. The drive shaft (5) is provided with a drive gear (20), and the driven shaft (6) is provided with a driven gear (17) that meshes with the drive gear (20). The drive shaft (5) and the driven shaft (6) are respectively provided with a first disc (4) and a second disc (14). The first disc (4) and the second disc (14) are evenly distributed with ventilation holes. The diameter of the ventilation holes is smaller than the particle size of the granular material. The edge contours of the first disc (4) and the second disc (14) are adapted to the inner wall of the butterfly valve tube. When the motor (19) is running, the drive shaft (5) rotates and drives the first disc (4) to deflect synchronously. At the same time, the drive gear (20) meshes with the driven gear (17) to rotate in the opposite direction, thereby driving the driven shaft (6) and the second disc (14) to deflect synchronously in the opposite direction, so as to realize the closure and opening of the material channel inside the butterfly valve tube. The air supply assembly includes a fan frame (11) and a fan (12). The fan (12) is mounted on one side of the measuring bucket assembly via the fan frame (11). The fan (12) is connected to the lower part of the storage bucket (8) via an air duct (13). The controller system includes a sensing unit, a data processing module, and a display module; The sensing unit includes an infrared rangefinder (1), a vortex flow meter (15), and a differential pressure gauge (22). The infrared rangefinder (1) is installed above the feed pipe (2) to measure the calibrated distance h1 from the horizontal reference plane to the feed inlet end face when the butterfly disc is closed in the butterfly valve pipe, and the distance h2 from the top of the granular material to the feed inlet end face; the vortex flow meter (15) is installed on the air duct (13) to measure the airflow rate; the differential pressure gauge (22) is installed on the main frame (7), and the two pressure taps of the differential pressure gauge (22) are respectively connected to the two differential pressure gauge taps (23) on the side wall of the butterfly valve pipe (3) through the differential pressure gauge tube (16) to measure the airflow pressure difference of the material layer. One of the differential pressure gauge taps (23) is parallel to the upper surface of the disc, and the other differential pressure gauge taps (23) is at a preset height above the disc. The height distance between the two differential pressure gauge taps (23) is the preset thickness of the material layer; The data processing module is used to calculate the difference between h1 and h2 to obtain the real-time thickness of the particulate material layer. When the real-time thickness of the material layer reaches the preset thickness of the material layer, the preset thickness of the material layer, the airflow rate, and the airflow pressure difference are substituted into the preset formula to calculate the specific surface area, and the calculation result is transmitted to the display module.

2. The measuring device according to claim 1, characterized in that, The preset formula is as follows: （1） （2） In the formula: K is the permeability of the material layer; q is the airflow rate through the material layer; ρ is the pneumatic viscosity; A is the cross-sectional area of ​​the particulate material inside the butterfly valve tube; P is the airflow pressure difference of the material layer; L is the filling length of the particulate material in the direction of fluid flow, i.e. the preset thickness of the material layer. is the specific surface area of ​​the particulate material; is the porosity of the particulate material, and is the preset calibration parameter for the corresponding material.

3. The measuring device according to claim 1, characterized in that, The controller system also includes a control module, and the fan (12) and motor (19) are connected to the control module respectively.

4. The measuring device according to claim 1, characterized in that, The adjacent mating ends of the storage bucket (8), butterfly valve pipe (3), and feed pipe (2) are connected by threaded pairs to achieve a detachable and sealed connection.

5. The measuring device according to claim 1, characterized in that, The upper part of the storage hopper (8) is provided with a first internal thread, the lower part of the outer wall of the butterfly valve pipe (3) is provided with a first external thread that mates with the first internal thread, the upper part of the butterfly valve pipe (3) is provided with a second internal thread, and the lower part of the outer wall of the feed pipe (2) is provided with a second external thread that mates with the second internal thread.

6. The measuring device according to claim 5, characterized in that, The bottom of the storage bin (8) is provided with a discharge end cap (9), the lower inner part of the storage bin (8) is provided with a third internal thread, and the outer wall of the upper part of the discharge end cap (9) is provided with a third external thread that mates with the third internal thread.

7. The measuring device according to claim 1, characterized in that, The driving shaft (5) and the driven shaft (6) respectively achieve radial rotation support and radial sealing through sealed bearings nested in the inner wall of the shaft hole.

8. The measuring device according to claim 1, characterized in that, The end of the differential pressure gauge tube (16) is provided with a quick-connect fitting (21), and the butterfly valve tube (3) is provided with a differential pressure gauge tapping interface (23) corresponding to the quick-connect fitting (21). The differential pressure gauge tube (16) is sealed and fixed to the differential pressure gauge tapping interface (23) through the quick-connect fitting (21).

9. A method for measuring the specific surface area of ​​static particulate materials, characterized in that, The measuring device as described in any one of claims 1-8 comprises the following steps: S1. Fill the butterfly valve tube (3) with the particle material to be tested to the preset thickness of the material layer; S2. Start the fan and collect the flow rate: After the material is loaded, start the fan (12). The airflow generated by the fan (12) is transported to the storage bucket (8) through the air duct (13). The instantaneous volume flow rate of the airflow is measured by the vortex flow meter (15) installed on the air duct (13). S3. Forming a uniform upward airflow: After the airflow enters the storage tank (8), it collides with the inner wall of the tank and naturally turns to form a uniform upward airflow. This upward airflow flows smoothly through the granular material layer loaded on the double discs in the butterfly valve pipe (3), forming a stable airflow pressure difference between the upstream and downstream ends of the material layer. S4, Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top of the feed pipe (2), forming a complete airflow measurement circuit. S5. Specific surface area calculation output: The data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, air flow rate, and air pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output. S6. Unloading and Resetting: After all measurement data has been collected, start the motor (19). The motor (19) drives the drive gear (20) on the drive shaft (5) to rotate through the output shaft. The driven gear (17) on the driven shaft (6) rotates synchronously in the opposite direction by the gear meshing transmission, thereby driving the first disc (4) and the second disc (14) to flip down synchronously to open the channel. The material that has been measured falls steadily into the storage bucket (8) by its own weight. After all the material has fallen, the unloading end cap (9) at the bottom of the storage bucket (8) can be screwed on directly to quickly remove it, completing the unloading without residue, and preparing for the measurement of the next set of samples.

10. A method for measuring the specific surface area of ​​a flowable particulate material, characterized in that, The measuring device as described in any one of claims 1-8 comprises the following steps: S1. Fill the butterfly valve tube (3) with the particle material to be tested until the feed tube (2) is full. The infrared rangefinder (1) measures the calibrated distance h1 from the horizontal reference plane to the feed port end face when the butterfly plate is closed in the butterfly valve tube, and the distance h2 from the top of the particle material to the feed port end face. The data processing module automatically calculates the difference between h1 and h2 to obtain the real-time thickness of the particle material layer. S2. Start the motor (19). The motor (19) drives the drive gear (20) on the drive shaft (5) to rotate through the output shaft. The driven gear (17) on the driven shaft (6) rotates synchronously in the opposite direction through gear meshing, thereby driving the first disc (4) and the second disc (14) to flip down synchronously to open the channel. At the same time, start the fan and flow rate acquisition: the airflow generated by the fan (12) is transported to the inside of the storage tank (8) through the air duct (13). The instantaneous volume flow rate of the airflow is measured by the vortex flow meter (15) installed on the section of the air duct (13). After the airflow enters the storage tank (8), it collides with the inner wall of the tank and naturally turns to form a uniform rising airflow. The rising airflow flows smoothly through the granular material layer in the butterfly valve pipe (3) and forms a stable airflow pressure difference between the material layers. The material relies on its own weight and the lift of the airflow to form a dynamic balance and flows down into the storage tank (8) at a stable speed. S3, Differential Pressure Acquisition: The two pressure taps of the differential pressure gauge are respectively connected to the differential pressure taps on the butterfly valve pipe wall through two independent differential pressure gauge tubes with pre-installed quick-connect fittings at the ends, thus completing the acquisition of differential pressure data between the upstream and downstream of the material layer; the airflow through the material layer is finally discharged smoothly from the top of the feed pipe (2), forming a complete airflow measurement circuit. S4. Specific surface area calculation output: When the real-time thickness of the particulate material layer reaches the preset thickness of the material layer, the data processing module calls the preset calibration porosity parameters of the corresponding material to be tested, substitutes the preset thickness of the material layer, airflow rate, and airflow pressure difference into the preset formula to complete the calculation, obtains the specific surface area value of the particulate material, and transmits the result to the display module for visualization output. S5. The material that has been measured falls steadily into the storage bucket (8) by its own weight. After all the material has fallen, the unloading end cap (9) at the bottom of the storage bucket (8) can be screwed on to remove it quickly, thus completing the unloading without residue and preparing for the measurement of the next set of samples.

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