Device and method for simulating movement trajectory and crushing state of material mass in pneumatic conveying pipeline

Abstract

The application provides a pipeline pneumatic material group movement track and breaking state simulation device and method, a test pipeline is a sleeve structure, including an inner tube and an outer tube, the inner tube and the outer tube are connected through a plurality of circumferentially distributed baffles, the baffles extend axially, thereby separating the space between the inner tube and the outer tube into a plurality of airflow channels, the outer tube is made of rigid material, the baffles and the inner tube are made of elastic material, the front end of the airflow channel is a test airflow inlet, the front end of the inner tube is a pneumatic material group inlet, a pulse sensor is arranged at the rear end of each airflow channel, the pulse sensor is embedded on the outer tube and located at the middle part between the adjacent two baffles, each pulse sensor is electrically connected with a computer through a wire. The application can track and detect the transportation track and breaking state of the material group in the pipeline.

Description

Technical Field

[0001] This invention relates to the field of material mass motion characteristic testing technology, and in particular to a device and method for simulating the motion trajectory and breakage state of material masses in pipeline pneumatic conveying. Background Technology

[0002] Pneumatic pipeline transportation is a common method of material handling. In underground tunnel support engineering, pneumatic pipelines are frequently used to transport concrete, loess, and backfill materials. Materials such as wet concrete tend to clump together, and during pipeline transportation, these clumps impact the inner wall of the pipeline, leading to clumping and pipeline wear. Patent CN201810060762.9 discloses a test system for assessing the rebound characteristics of fine particles impacting the channel wall at high speed. This system includes a test chamber, a particle injection system, a target specimen positioning device, a light source system, a vacuum system, an optical testing system, and a synchronous control system for controlling the light source and optical testing systems. This system can simultaneously acquire the particle shape, size, and translational and rotational speeds before and after impacting the wall, but it cannot accurately describe the impact position and magnitude of the impact force. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention aims to provide a device and method for simulating the movement trajectory and breakage state of material clumps in pipeline pneumatic conveying, so as to track and detect the transport trajectory and breakage of material clumps in pipelines.

[0004] To achieve the above objectives, this invention proposes a device for simulating the motion trajectory and breakage state of a material clump in a pneumatic conveying pipeline. The device includes a test pipeline and a computer. The test pipeline is arranged laterally and has a sleeve structure, comprising an inner pipe and an outer pipe. The inner and outer pipes are connected by several circumferentially distributed partitions. The partitions extend axially, thereby dividing the space between the inner and outer pipes into several airflow channels. The outer pipe is made of a rigid material, while the partitions and the inner pipe are made of elastic materials. The front end of each airflow channel is the test airflow inlet, and the front end of the inner pipe is the inlet for the pneumatically conveyed material clump. A pulse sensor is installed at the rear end of each airflow channel, embedded in the outer pipe and located in the middle between two adjacent partitions. Each pulse sensor is electrically connected to the computer via a wire.

[0005] In the above scheme: the partition and the inner tube are integrally formed by casting or die casting of elastic polymer. Both the partition and the inner tube are made of elastic material, and the integral forming process is convenient.

[0006] In the above scheme: the partition and the outer tube are connected by sealant or by heat shrink sealing.

[0007] The above scheme also includes a high-speed camera, which is positioned on the side of the test pipeline.

[0008] This invention also proposes a method for simulating the motion trajectory and breakage state of material clumps in pipeline pneumatic conveying, based on the aforementioned device for simulating the motion trajectory and breakage state of material clumps in pipeline pneumatic conveying, comprising the following steps:

[0009] S1. Use a computer to calibrate the pressure pulse signal, including the calibration of the pressure pulse size of particles or material clumps impacting the inner tube and the calibration of the pressure position, which is divided into lateral position and radial position.

[0010] 1) At the test airflow inlet, a uniform test airflow is introduced into each airflow channel, and the computer records the pulse signal of each airflow channel as the basic pulse signal through the pulse sensor;

[0011] 2) At the inlet of the pneumatically conveyed material, granules with different particle characteristics are pneumatically conveyed under different wind speed conditions. The granules will collide with the inner tube, causing the inner tube to deform, which in turn causes changes in the airflow in the corresponding airflow channel. The abnormal pulse signal can be detected by the pulse sensor in the corresponding airflow channel. The radial position of the impact can be determined according to the specific airflow channel of the granule impact. The distance between the point of impact of the granule on the inner tube and the pulse sensor will cause the difference in the pulse signal. The axial position of the granule impact can be determined by using this difference.

[0012] The pulse signals of particles with different particle characteristics transported under different wind speed conditions were recorded separately, and then the samples were obtained by dividing them by the basic pulse signal.

[0013] 3) Input the sample data into the computer and use the "artificial neural network" or "support vector machine" algorithm to optimize the program for sample training, and build a database for calibrating the position and pressure of a certain characteristic particle impacting a certain airflow channel at a certain conveying speed;

[0014] S2. Measurement of impact location and breakage of material clumps conveyed by pneumatic conveying;

[0015] 1) At the test airflow inlet, continue to introduce uniform test airflow into each airflow channel;

[0016] 2) At the inlet of the pneumatic material clump, the material clump to be tested is conveyed. The material clump generates impact and friction inside the inner tube, resulting in a large indentation at the corresponding position of the inner tube. The pulse signal generated is acquired by the pulse sensor and input into the computer for database matching to obtain the specific location and pressure.

[0017] In the above scheme: on the time axis, the magnitude and time of the pulse signal obtained by the pulse sensor can be used to obtain the dispersion time and size of the material clump.

[0018] In the above scheme, the different particle characteristics include different particle size, different density, and different shape.

[0019] The beneficial effects of this invention are:

[0020] 1. It eliminates the need for a dense array of pressure sensors to monitor pressure signals in real time, saving significant maintenance costs associated with pressure sensors. Flow or pulsation sensors can be placed at the outlet of each airflow channel.

[0021] 2. It breaks through the limitations of relying solely on high-speed cameras for positioning. By using a pulse sensor, it can obtain both the pressure position in the pipeline and the magnitude of the material impact force, especially the time and size of the material breakup.

[0022] 3. After training samples through artificial neural networks or support vector machines, the constructed database can realize the pipeline conveying characteristics analysis of particle clusters with different sizes, densities, shapes and other characteristics under different conveying speeds, and obtain information such as the collision pressure, crushing time and location of material particles.

[0023] 4. It cleverly utilizes the differences in airflow pulse signals generated at different pipe cross-sections (as well as the degree of transmission distance delay of the airflow pulse signals) to obtain the particle impact location, breakage location, and pressure magnitude.

[0024] 5. The depth of the indentation on the pipe wall caused by the impact of particles or material clumps can be used to characterize both the impact pressure of the particles and the magnitude of friction, enabling precise positioning. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a device for simulating the movement trajectory and breakage state of material clumps in pipeline pneumatic conveying.

[0026] Figure 2 yes Figure 1 Sectional view at point D-D'.

[0027] Figure 3 yes Figure 1 Sectional view at point E-E'. Detailed Implementation

[0028] like Figure 1 As shown in Figure 3, a device for simulating the movement trajectory and breakage state of a material clump in a pipeline pneumatic conveying system mainly consists of a test pipeline 1 and a computer, with the test pipeline 1 arranged horizontally.

[0029] The test pipe 1 is a sleeve structure, including an inner pipe 2 and an outer pipe 3. The inner pipe 2 and the outer pipe 3 are connected by several circumferentially distributed baffles 4. The baffles 4 extend axially, thereby dividing the space between the inner pipe 2 and the outer pipe 3 into several airflow channels 5.

[0030] The outer tube 3 is made of rigid material, while the partition 4 and the inner tube 2 are made of elastic material.

[0031] The front port of airflow channel 5 is the test airflow inlet A, and the front port of inner tube 2 is the air-pumped material clump inlet B. A pulse sensor 6 is installed at the rear end of each airflow channel 5, embedded in the outer tube 3 and located in the middle between two adjacent partitions 4. Each pulse sensor 6 is electrically connected to a computer via a wire 7.

[0032] Ideally, the partition 4 and the inner tube 2 are integrally formed by casting or die casting with an elastic polymer. Both the partition 4 and the inner tube 2 are made of elastic materials, and integral forming is convenient.

[0033] Ideally, the partition 4 and the outer tube 3 should be connected by sealant or by heat shrink sealing.

[0034] Ideally, it should also include a high-speed camera, which is positioned to the side of test pipe 1.

[0035] A method for simulating the motion trajectory and breakage state of a material clump in a pipeline pneumatic conveying system, based on the aforementioned simulation device for simulating the motion trajectory and breakage state of a material clump in a pipeline pneumatic conveying system, includes the following steps:

[0036] S1. Use a computer to calibrate the pressure pulse signal, including calibrating the size of the pressure pulse when particles or material clumps 8 impact the inner tube 2 and calibrating the pressure position, which is divided into lateral position and radial position.

[0037] 1) At the test airflow inlet A, uniform test airflow is introduced into each airflow channel 5. Each airflow channel 5 is sequentially labeled as n1, n2, n3, ..., n1. The computer records the pulse signal of each airflow channel 5 as the basic pulse signal F0 through the pulse sensor 6.

[0038] 2) At the inlet B of the pneumatically conveyed material mass, granules with different particle characteristics are pneumatically conveyed under different wind speed conditions. A high-speed camera is used to capture and record the impact positions of the granules in the pipeline: x1, x2, x3...x j .

[0039] The pellets impact the inner tube 2, causing it to deform. This deformation alters the airflow within the corresponding airflow channel 5, which in turn detects an abnormal pulse signal (n) via the pulse sensor 6 within the airflow channel 5. i x j(Location).

[0040] The impact of the particle ball can determine both its radial and axial positions. The working principle is as follows: the pressure generated by the collision and friction of the particle ball with the inner tube 2, causing indentation in the inner tube 2, can be determined based on the magnitude of the pulse signal detected at the end of the airflow channel 5. In other words, the magnitude of the pulse signal detected by the pulse sensor 6 represents the magnitude of the impact pressure. Based on the difference in pulse signals detected by the pulse sensor 6 and the corresponding position of the airflow channel 5, the location where the particle ball impacts or wears the inner tube 2 can be inferred. Simultaneously, a high-speed camera captures and tracks the trajectory of the particle ball, used for comparison and calibration of the collision position based on the difference in pulse signals.

[0041] Specifically, the radial position is determined as follows: when a particle impacts a certain airflow channel 5, that channel 5 generates a pulse signal, thus determining the specific radial position of the impact (channel n). i Axial position determination: The distance between the point of impact of the particle into the inner tube 2 and the pulse sensor 6 will cause differences in the pulse signal. For example, if the same particle impacts the inner tube 2 at positions x1 and x3 with the same force, although the impact force at x1 and x3 is the same (i.e., the degree of indentation in the inner tube 2 is the same), the generated pulse signals should theoretically be the same. However, the distance from the particle impact point x1 to the pulse sensor 6 results in a longer signal delay and a greater reduction in pulse airflow. Conversely, the distance from the particle impact point x3 to the pulse sensor 6 results in a smaller signal delay and a less reduction in pulse airflow. Therefore, the same particle impacting the inner tube 2 wall at positions x1 and x3 with the same force produces a signal difference, which is used to determine the axial position of the particle impacting the pipe. Furthermore, a high-speed camera can also simultaneously capture the impact position, allowing for comparison and optimization of the pulse signals. In other words, the axial position of the particle impacting the pipe can be observed and captured in real time by a high-speed camera, or obtained through the pulse signal delay information of the pressure.

[0042] Extensive experiments were conducted to record the pulse signals of granules with different particle characteristics transported under different wind speed conditions. The records are shown in Table 1. The data were then uniformly divided by the basic pulse signal F0 to obtain sample data, which was used to subtract the influence of the basic pulse signal.

[0043] Table 1. Sample of signals collected from the location of material clumps or particles impacting the inner tube.

[0044]

[0045] 3) Input the sample data into the computer and use the "artificial neural network" or "support vector machine" algorithm to optimize the program for sample training, and construct a database for calibrating the position and pressure of a certain characteristic particle impacting a certain airflow channel 5 at a certain conveying speed.

[0046] S2. Measurement of impact position and breakage of material clumps conveyed by pneumatic conveying.

[0047] 1) At the test airflow inlet A, continue to introduce uniform test airflow into each airflow channel 5.

[0048] 2) At the inlet B of the pneumatic material mass, the material mass 8 to be tested is conveyed. The material mass 8 generates impact and friction in the inner tube 2, and a large indentation is generated at the corresponding position of the inner tube 2. The resulting pulse signal is acquired by the pulse sensor 6 and input into the computer for database matching to obtain the specific position and pressure.

[0049] Assuming that material agglomeration 8 collides with the x1 position (n1x1) of the n1 airflow channel 5 in the test pipe 1, material agglomeration 8, similar to large particles, experiences significant impact and friction, resulting in a large indentation h1 at position x1 of the n1 airflow channel 5. The resulting pulse signal is acquired by pulse sensor 6 and input into a computer for database matching to obtain the specific location and pressure magnitude (the pressure magnitude can be used to approximately characterize the wear degree of material agglomeration 8). Upon the first impact, material agglomeration 8 disperses (the first impact generates a pulse signal, recorded at time t1), forming a first dispersed particle 81 and a semi-dispersed material agglomeration 82. The semi-dispersed material agglomeration 82, being smaller in volume than material agglomeration 8, impacts the inner tube 2 under the thrust and buoyancy of the pneumatic conveying. Following the same principle, the specific impact location x2 and pressure of the semi-dispersed material agglomeration 82 are obtained. Furthermore, the semi-dispersed material agglomeration 82 breaks upon a second impact (recorded at time t2), forming a second dispersed particle 821 and a third dispersed particle 822, similar to a single particle impacting the inner tube 2. Similarly, the specific impact positions and pressure magnitudes of the second and third dispersed particles 821 and 822 are obtained. The specific impact position of the first dispersed particle 81 in the figure is x3. On the time axis, the magnitude and time of the pulse signal obtained by the pulse sensor 6 can be used to obtain the dispersion time and size of the material clump 8 (the size of each particle after dispersion of the material clump 8 is different, and the impact pressure of each particle with the inner tube 2 is also different).

[0050] Ideally, the different particle characteristics include different particle size, different density, and different shape.

Claims

1. A device for simulating the trajectory and breakage state of a material clump in a pneumatic pipeline conveying system, comprising a test pipeline (1) and a computer, wherein the test pipeline (1) is arranged laterally, characterized in that: The test pipe (1) is a sleeve structure, including an inner pipe (2) and an outer pipe (3). The inner pipe (2) and the outer pipe (3) are connected by several circumferentially distributed partitions (4). The partitions (4) extend axially, thereby dividing the space between the inner pipe (2) and the outer pipe (3) into several airflow channels (5). The outer pipe (3) is made of rigid material, while the partitions (4) and the inner pipe (2) are made of elastic material. The front end of the airflow channel (5) is the test airflow inlet (A), and the front end of the inner pipe (2) is the air-carrying material clump inlet (B). A pulse sensor (6) is provided at the rear end of each airflow channel (5). The pulse sensor (6) is embedded in the outer pipe (3) and located in the middle between two adjacent partitions (4). Each pulse sensor (6) is electrically connected to the computer through a wire (7). At the inlet (B) of the pneumatically conveyed material, granules with different particle characteristics are pneumatically conveyed under different wind speed conditions. The granules will hit the inner tube (2), causing the inner tube (2) to deform, which will cause the airflow in the corresponding airflow channel (5) to change. The abnormal pulse signal can be detected by the pulse sensor (6) in the corresponding airflow channel (5). The radial position of the impact can be determined according to the specific airflow channel (5) of the granules. The distance between the granules hitting the inner tube (2) and the pulse sensor (6) will cause the difference in the pulse signal. The axial position of the impact of the granules can be determined by using this difference.

2. The device for simulating the trajectory and breakage state of material clumps in pipeline pneumatic conveying according to claim 1, characterized in that: The partition (4) and the inner tube (2) are integrally formed by casting or die casting of an elastic polymer.

3. The device for simulating the trajectory and breakage state of material clumps in pipeline pneumatic conveying according to claim 1, characterized in that: The partition (4) and the outer tube (3) are connected by sealant or by heat shrink sealing.

4. The device for simulating the trajectory and breakage state of material clumps in pipeline pneumatic conveying according to claim 1, characterized in that: It also includes a high-speed camera, which is positioned to the side of the test pipe (1).

5. A method for simulating the motion trajectory and breakage state of a material clump in a pipeline pneumatic conveying system, characterized in that: The device for simulating the trajectory and breakage state of material clumps in pipeline pneumatic conveying according to any one of claims 1-4 includes the following steps: S1. Use a computer to calibrate the pressure pulse signal, including the calibration of the pressure pulse size and the calibration of the pressure position when particles or material clumps (8) impact the inner tube (2). The pressure position is divided into lateral position and radial position. 1) At the test airflow inlet (A), a uniform test airflow is introduced into each airflow channel (5), and the computer records the pulse signal of each airflow channel (5) as the basic pulse signal through the pulse sensor (6); 2) At the inlet (B) of the pneumatically conveyed material, different particle balls with different particle characteristics are pneumatically conveyed under different wind speed conditions. The particle balls will hit the inner tube (2), causing the inner tube (2) to deform, which will cause the airflow in the corresponding airflow channel (5) to change. The abnormal pulse signal can be detected by the pulse sensor (6) in the corresponding airflow channel (5). The radial position of the impact can be determined according to the specific airflow channel (5) of the particle ball. The distance between the point of the particle ball hitting the inner tube (2) and the pulse sensor (6) will cause the difference in the pulse signal. The difference can be used to determine the axial position of the particle ball impact. The pulse signals of particles with different particle characteristics transported under different wind speed conditions were recorded separately, and then the samples were obtained by dividing them by the basic pulse signal. 3) Input the sample data into the computer and use the "artificial neural network" or "support vector machine" algorithm to optimize the program for sample training, and construct a database for calibrating the position and pressure of a certain characteristic particle hitting a certain airflow channel (5) at a certain conveying speed; S2. Measurement of impact location and breakage of material clumps conveyed by pneumatic conveying; 1) At the test airflow inlet (A), continue to introduce uniform test airflow into each airflow channel (5); 2) At the inlet (B) of the pneumatic material mass, the material mass (8) to be tested is conveyed. The material mass (8) generates impact and friction in the inner tube (2). A large indentation is generated at the corresponding position of the inner tube (2). The pulse signal generated is acquired by the pulse sensor (6) and input into the computer for database matching to obtain the specific position and pressure.

6. The method for simulating the motion trajectory and breakage state of material clumps in pipeline pneumatic conveying according to claim 5, characterized in that: On the time axis, the magnitude and time of the pulse signal obtained by the pulse sensor (6) can be used to obtain the dispersion time and size of the material clump (8).

7. The method for simulating the motion trajectory and breakage state of material clumps in pipeline pneumatic conveying according to claim 5, characterized in that: Different particle characteristics include different particle size, different density, and different shape.

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