Automatic sand screening device for physical simulation experiment of sand box

Abstract

The utility model relates to geological physics simulation experiment equipment technical field, concretely relates to a sand box physics simulation experiment homogeneous quartz sand automatic sand screening device, the quartz sand automatic sand screening device, including gradient setting's screen group, mechanical vibration excitation device, vibration control module, a plurality of different mesh number's screen is arranged gradually from small to big according to mesh number, and is set gradually in turn mutual nesting, the top of outer frame has at least two clamping grooves, the bottom of outer frame has the clamping block, and the screen of upper and lower adjacent layers is connected into an integral structure through clamping groove and clamping block cooperation mutual nesting, mechanical vibration excitation device is connected with at least one screen in screen group, and vibration control module is used for controlling mechanical vibration excitation device and carries out vibration according to preset frequency and amplitude. The utility model discloses sand screening device has the advantages such as high screening efficiency, good quality, better satisfy the sand box physics simulation quartz sand preparation demand, reduce manpower, material resources requirement, make the experimental efficiency improve greatly.

Description

Technical Field

[0001] This utility model relates to the technical field of geophysical simulation experimental equipment, specifically to an automated screening device for homogeneous quartz sand used in physical simulation experiments of sand box structures, which is particularly suitable for the particle size classification and control of quartz sand in high-precision structural deformation simulation. Background Technology

[0002] Sandbox physical simulation is a technique that uses laboratory-scale models to reproduce the deformation process of geological structures. It is mainly used to study the deformation mechanisms of crustal rocks under tectonic stress (such as folding, faulting, and thrust zones). Its core principle is to simulate the mechanical behavior of geological bodies under controllable experimental conditions (materials, boundary constraints, loading methods, etc.) to reveal the physical laws of tectonic evolution.

[0003] Since the 19th century, sand box modeling has gone through three major stages: the nascent stage, the promotion stage, and the mature stage of similarity theory. The early 19th century to the mid-20th century was the nascent stage of sand box physical simulation. During this stage, experiments lacked theoretical guidance, material selection was highly arbitrary, and the uneven particle size of quartz sand led to significant deviations between the deformation mechanism and actual examples. After the introduction of Coulomb's wedge theory in the 1960s-1980s, sand box physical simulation technology gradually entered the promotion stage. Researchers discovered that the self-similar growth characteristics of the punching zone are highly sensitive to the friction coefficient of sand particles, but due to the limited efficiency of manual sieving, it was difficult to obtain sand samples of specific mesh sizes in batches. In the 1990s, researchers proposed the critical wedge steady-state theory, which, based on the material characteristics of quartz sand, requires experimental materials to have strict mechanical similarity, that is, the raw materials in the sand box experiment must be highly consistent with the actual objects to accurately simulate the real friction of sand and gravel. Therefore, in the process of sand box physical simulation research, material standardization has become the core requirement for the reliability of experimental results.

[0004] However, existing sandbox physical simulation experiments still have the following shortcomings: (1) Non-standardized operation: Experimenters need to manually tap the screen, and the tapping force is difficult to quantify, which leads to fluctuations in the breakage rate of sand and gravel particles inside the sand box. The breakage rate of sand and gravel caused by the unstable tapping force during manual screening is as high as 7%-15%, resulting in poor reliability of the physical simulation experiment of the sand box.

[0005] (2) Insufficient accuracy of sand box grading: Traditional screens have overlapping mesh sizes, resulting in mixed particle sizes of sand and gravel screened by adjacent screens, and insufficient screening. For example, 60-mesh sand mixed into the 80-mesh range will cause fluctuations in the results of continuous vibrating sand and gravel grading.

[0006] (3) Low efficiency: Traditional sand box physical simulation takes more than 30 minutes for a single screening. The sand screening labor intensity is high and a lot of manpower and material resources are required, which is difficult to meet the sand demand of large-scale impact wedge experiments.

[0007] (4) Pollution risk: In the traditional sand box physical simulation experiment, an open sieve is used. The amount of dust emitted during the sand screening process is large, the working environment of workers is poor, and it is very harmful to their health. Moreover, the sand screening process seriously affects the cleanliness of the experimental environment, which affects other research work in the same laboratory.

[0008] (5) Uneven sand density leads to fault slip path deviation: In sand box experiments simulating thrust faults, if the local density difference of the sand layer is too large (such as due to uneven material distribution or insufficient vibration compaction), the fault slip path will deviate from the preset direction. For example, low-density areas (loose sand layers) may preferentially undergo shear deformation, while high-density areas (dense sand layers) form a resistance barrier, ultimately causing the fault fracture surface to be distorted, affecting the reliability of the experimental conclusions. Utility Model Content

[0009] The purpose of this invention is to overcome the shortcomings of existing technologies, such as low accuracy in sand box physical simulation experiments due to insufficient quality of quartz sand, low efficiency, high pollution, and high energy consumption of existing sand screening devices, and to provide an automatic sand screening device for homogeneous quartz sand in sand box physical simulation experiments.

[0010] To achieve the above objectives, this utility model provides the following technical solution: An automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment includes the following components: a gradient-set screen group, a mechanical vibration excitation device, and a vibration control module.

[0011] The gradient-set screen group includes multiple screens with different mesh sizes, and all screens are set in ascending order of mesh size.

[0012] The gradient-set screen group consists of screens that can be nested into each other sequentially.

[0013] Each screen in the gradient-set screen group has an outer frame of the same size, and inspection screens with different mesh sizes are set in the outer frame; the top of the outer frame has at least two slots, and the bottom of the outer frame has a locking block. The screens of adjacent layers are nested together to form an integrated structure through the slots and locking blocks of the outer frame.

[0014] The mechanical vibration excitation device is disposed on the side of the gradient-arranged screen group, and the mechanical vibration excitation device is connected to at least one screen in the screen group.

[0015] The vibration control module is electrically connected to the mechanical vibration excitation device, and the vibration control module is used to control the mechanical vibration excitation device to vibrate according to a preset frequency and amplitude.

[0016] This invention uses standard test sieves as its core. First, 40-mesh, 60-mesh, 80-mesh, and 100-mesh standard test sieves are stacked from top to bottom. The sieves are fixed by a bottom snap-fit ​​structure (slots and blocks), thereby achieving the grading of quartz sand of different particle sizes. This provides quartz sand of different particle sizes for subsequent physical simulation experiments in sand boxes, providing a basis for mutual verification between experiments and examples.

[0017] The vibration control module enables the mechanical vibration excitation device to vibrate at a controllable frequency and amplitude, driving the quartz sand screen assembly to vibrate and screen. By setting appropriate vibration frequency and amplitude of the mechanical vibration excitation device, the automatic screening quality of the quartz sand is ensured to meet design expectations. Simultaneously, a negative pressure dust removal unit is installed on the side or above the screen assembly to remove dust, improve air quality during the sand screening process, and reduce dust pollution.

[0018] Furthermore, the test sieves within each sieve of the gradient-set sieve group are: 40-mesh standard test sieve, 60-mesh standard test sieve, 80-mesh standard test sieve, and 100-mesh standard test sieve. Multiple sieves of different mesh sizes are arranged layer by layer according to their mesh count, with the larger mesh size test sieves placed on the upper layer and the smaller mesh size test sieves placed on the lower layer, with the mesh count increasing from top to bottom. This constitutes an automatic sieve equipment for homogeneous quartz sand, obtaining standard quartz sand that can be better applied to physical simulation experiments in sand boxes.

[0019] Furthermore, in the screen assembly, the standard inspection screen layer spacing between adjacent screens is 40-80mm, preferably 50±2mm. Appropriate layer spacing ensures sufficient space for material movement during vibrating screening, provides good vibration transmission, prevents material blockage and accumulation, and ensures screening efficiency.

[0020] Furthermore, all inspection sieves are made of 304 stainless steel.

[0021] Furthermore, the outer frame of the screen is circular.

[0022] Furthermore, all test sieves are cylindrical sieve chambers. Preferably, the wall thickness of the test sieve is 2-4 mm.

[0023] Preferably, the inspection sieve is a cylindrical sieve with a diameter of 600-800 mm.

[0024] Furthermore, multiple standard test sieves in the sieve assembly are equipped with annular rubber sealing rings between adjacent layers, and the annular rubber sealing rings have a Shore hardness ≥60HA. Preferably, the Shore hardness of the annular rubber sealing rings is ≥80HA. The hardness of the rubber sealing rings is tested according to GB / T 6031. The annular rubber sealing rings separate the standard test sieves, control the spacing, and prevent quartz sand from overflowing and scattering, which could cause experimental errors.

[0025] The standard test sieve used in this invention is a commercially available standard test sieve, also known as a standard sieve or laboratory sieve. Specifically, a sieve conforming to the GB / T 6003.1 standard can be used, with an outer diameter configured as described above of 600-800 mm.

[0026] Furthermore, the outer frame of the screen is circular, and a fixing screw hole is provided on the outer side of the outer frame for fixing adjacent screens together.

[0027] Furthermore, the mechanical vibration excitation device is an eccentric mass exciter. A motor drives the eccentric mass block to rotate, generating periodic centrifugal excitation force. This device is simple in structure and low in cost.

[0028] The eccentric mass vibrator generates centrifugal force F for: F=m·r·ω 2 in, F: Centrifugal force; m: Mass of the eccentric block; r: Eccentricity (distance from the center of mass to the center of rotation); ω: angular velocity of rotation ( ω=2πf , f (for frequency).

[0029] The centrifugal force and amplitude can be controlled by adjusting the motor speed of the eccentric mass vibrator.

[0030] Furthermore, the mechanical vibration excitation device and the screen assembly are connected by a lever, and the position of the mechanical vibration excitation device on the lever is adjustable.

[0031] Since the vibration frequency of an eccentric mass vibrator is related to the excitation force, and the excitation force is proportional to the square of the frequency, the vibration frequency of the eccentric mass vibrator can be controlled. f : f=n / 60 in, n It is the motor speed (RPM).

[0032] Correspondingly, the eccentric mass exciter generates centrifugal force. F for: F=m·r·ω 2 =m·r·(2πf) 2 Furthermore, the vibration control module can control the eccentric mass vibrator to vibrate according to the program. The motor speed first runs at a high speed for 3-5 minutes, then at a medium speed for 2-4 minutes, and finally stops.

[0033] Due to the differences in particle size, quartz sand is sequentially screened through multiple sieves of different mesh sizes to obtain quartz sand with a standard particle size range.

[0034] Furthermore, a partition plate is provided on the side of the screen group with gradient settings. The partition plate is arranged in layers according to the matching of each screen. Each partition plate can divide a screen accordingly, so that the quartz sand on the screen is divided into two parts.

[0035] The size of the partition area corresponding to each partition plate is determined according to a pre-designed ratio. When the partition plates are working, they separate the screened quartz sand according to the target quantity. The quartz sand can be poured out from the side of the screen assembly to obtain the total amount of quartz sand planned according to the corresponding particle size ratio.

[0036] Furthermore, the eccentric mass vibrator is equipped with a PID closed-loop controller to automatically adjust the excitation parameters according to the screen load.

[0037] Furthermore, the automatic quartz sand screening device is also equipped with a cover, and the gradient-arranged screen group, mechanical vibration excitation device, vibration control module and negative pressure dust removal unit are all installed inside the cover.

[0038] Furthermore, it also includes a negative pressure dust removal unit; the negative pressure dust removal unit is located on the side or above the screen group, and is used to perform negative pressure suction and purification of the dust volatilized by the vibration of the quartz sand on the screen group.

[0039] Furthermore, the negative pressure dust removal unit includes a cyclone separator, a HEPA filter, and a negative pressure fan arranged in series.

[0040] Preferably, the negative pressure dust removal unit can maintain a negative pressure of -50Pa to -100Pa.

[0041] HEPA filters can filter 0.3μm dust with an efficiency of over 99.97%.

[0042] The negative pressure fan has an air volume of not less than 300m³. 3 / h.

[0043] HEPA (High Efficiency Particulate Air) filters employ a high-efficiency filtration structure to effectively intercept and filter various suspended particulate matter in the air, including dust, pollen, mold spores, and bacteria. All dust generated during the quartz sand screening process can be effectively filtered and removed, ensuring the purity of the quartz sand obtained from screening, reducing the impact of dust, and at the same time ensuring the air quality of the experimental environment and eliminating the risk of occupational diseases caused by dust.

[0044] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model provides an automatic quartz sand screening device, which achieves high-throughput precision grading of 40-100 mesh quartz sand through the coordinated action of modular screen groups, mechanical vibration control, and negative pressure dust removal unit. It features high screening efficiency and good screening quality, meeting the requirements for quartz sand preparation in physical simulations of sand boxes, significantly reducing manpower and material requirements, and greatly improving experimental efficiency.

[0045] 2. The automatic quartz sand screening device of this utility model realizes the mechanical vibration excitation device to vibrate at a controllable frequency and amplitude through the control module, which drives the quartz sand screen group to vibrate and screen. By setting an appropriate vibration frequency and amplitude of the mechanical vibration excitation device, the automatic screening quality of quartz sand is ensured to meet the design expectations.

[0046] 3. This utility model of automatic quartz sand screening device adopts a gradient-arranged screen group. Each screen has the same outer frame size, and screens of different mesh sizes are nested and connected to each other in adjacent layers through slots and blocks to form an integrated structure. It has high vibration stability, avoiding the problem of substandard quartz sand screening quality caused by inconsistent vibration of some screens. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the structure of a multi-layer screen group in an automatic quartz sand screening device.

[0048] Figure 2 This is a flowchart of a physical simulation experiment using a sandbox.

[0049] Figure 3 Design drawings for a series of sandbox physical simulation experimental devices for multi-stage superimposed structural processes.

[0050] Marked in the image: 1-Feed inlet; 2-Vibration motor; 3-Screen assembly; 4-Sand collection drawer. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to specific embodiments. However, it should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0052] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of this utility model is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the utility model solution or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on this utility model.

[0053] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0054] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0055] Furthermore, in the description of the embodiments of this utility model, "several", "multiple", and "several" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0056] Furthermore, in the description of the technical solution of this utility model, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "equipped with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0057] Example 1 like Figure 1 The diagram illustrates an automatic sand sieving device for homogeneous quartz sand in a sand box physical simulation experiment. It includes a gradient-arranged sieve group, a mechanical vibration excitation device, and a vibration control module. The gradient-arranged sieve group comprises: a 40-mesh standard test sieve, a 60-mesh standard test sieve, an 80-mesh standard test sieve, and a 100-mesh standard test sieve. All sieves are arranged in ascending order of mesh size from top to bottom. The sieves of all four layers are made of 304 stainless steel woven mesh (wire diameter 0.12mm ± 0.01mm). The outer frame of the four-layer standard test sieve has a diameter of 600mm and a height of 120mm.

[0058] The outer frame of the screen adopts a skeleton structure with a wall thickness of 3mm. Each screen has the same outer frame size, and the upper part of the outer frame has four slots evenly arranged in a circular shape. Four locking blocks are evenly arranged at the bottom of the outer frame, and the locking blocks and slots are mutually matched. The slots are 12mm deep and 6mm wide; the locking blocks are 10mm high and approximately 6.1mm wide, resulting in an interference fit of 0.05-0.1mm between the slots and blocks. Adjacent layers of screens are nested together to form a single structure through the interlocking of the slots and blocks.

[0059] The inner ring of the outer frame, which features locking blocks and slots, also includes an annular sealing groove, within which an annular rubber sealing ring is positioned. When adjacent standard test sieves are engaged via the locking blocks and slots, the annular rubber sealing ring is compressed, ensuring a tight fit between the adjacent standard test sieves. The annular rubber sealing ring has a Shore hardness of 80 HA and a compression set of ≤15%. In this way, the outer frames of each sieve in all the gradient-set sieve groups are nested within each other, forming a unified sieve assembly.

[0060] The mechanical vibration excitation device is a YZO-20-6 type eccentric mass vibrator, with an eccentric mass of 2.5 kg, an eccentricity of 50 mm, a maximum excitation force of 2000 N, and a frequency range of 5-50 Hz. The mechanical vibration excitation device is installed on the side of the screen assembly and is connected to the 80-mesh standard inspection sieve in the third layer of the screen assembly.

[0061] A PLC controller is selected as the vibration control module. The PLC controller is electrically connected to the mechanical vibration excitation device. The vibration control module is used to control the mechanical vibration excitation device to vibrate according to a preset frequency and amplitude. Specifically, this embodiment uses a Siemens S7-1200 PLC controller. The PLC controller is pre-programmed as follows: Stage 1, lasting 4 minutes, motor speed 1500 RPM, amplitude 3 mm; Stage 2, lasting 7 minutes, motor speed 1200 RPM, amplitude 1.5 mm.

[0062] Before conducting the physical simulation experiment of the sand box, according to Figure 2 Prepare according to the procedure shown. After determining the experimental materials, proceed with the quartz sand sieving.

[0063] The aforementioned automatic quartz sand screening device has extremely high screening efficiency. With a feed of 50 kg of quartz sand, the screening process can be completed in an average of 10-15 minutes. Furthermore, the screened quartz sand has a 100% qualified particle size rate.

[0064] Furthermore, a negative pressure dust removal unit is also included. A casing is installed outside the automatic quartz sand screening device, housing the screen assembly, mechanical vibration excitation device, vibration control module, and negative pressure dust removal unit. The negative pressure dust removal unit includes a cyclone separator, a HEPA filter, and a negative pressure fan connected in series. The air inlet of the cyclone separator is located above the screen assembly, and the negative pressure fan provides a negative pressure of -50Pa to -100Pa. Dust volatilized from the vibrating quartz sand on the screen assembly first passes through the cyclone separator for dust removal, then through the HEPA filter for dust removal, and is purified by negative pressure suction. The HEPA filter has an efficiency of over 99.97% for filtering 0.3μm dust, and the negative pressure fan has an air volume of not less than 300m³. 3 / h. The on-site environment was basically completely purified of dust pollution, with virtually no dust pollution, and the quartz sand obtained from screening had very little dust residue.

[0065] Example 2 According to Example 1, in an automatic sand screening device for homogeneous quartz sand used in a physical simulation experiment, a mechanical vibration excitation device and a screen assembly are connected by a lever. One end of the lever is connected to the screen, and the other end is connected to the housing. The position of the mechanical vibration excitation device on the lever is adjustable. The vibration frequency of the eccentric mass exciter... f : f=n / 60 .in, n It is the motor speed (RPM).

[0066] Correspondingly, the centrifugal force generated by the eccentric mass exciter is F=m·r·ω 2 =m·r·(2πf) 2 .

[0067] The vibration frequency of the eccentric mass vibrator is related to the excitation force, which is proportional to the square of the frequency. The vibration control module can control the eccentric mass vibrator to vibrate according to a program. The eccentric mass vibrator is equipped with a PID closed-loop controller, which automatically adjusts the excitation parameters according to the screen load. For example, it first controls the screen vibration frequency to 15Hz for 5 minutes, then controls the screen vibration frequency to 22Hz for 4 minutes, and finally stops running. The quartz sand added by the automatic sand screening device is screened sequentially due to differences in particle size, falling into screens of different mesh sizes.

[0068] The automatic sand screening device is externally enclosed by a casing, inside which are housed the screen assembly, mechanical vibration excitation device, vibration control module, and negative pressure dust removal unit. Inside the casing are also partition plates located on the sides of the gradient-arranged screen assembly. These partition plates are layered and matched to each screen, with each partition plate corresponding to a specific screen, dividing the quartz sand on the screen into two parts. Positioned according to a pre-designed ratio, the partition plates separate the screened quartz sand according to the target quantity when operating. The quartz sand is then poured out from the side of the screen assembly, obtaining the total amount of quartz sand used according to the planned particle size ratio.

[0069] This invention relates to an automatic sand screening device for homogeneous quartz sand in physical simulation experiments using a sand box. Compared to traditional manual screening methods, it increases quartz sand screening efficiency by 300% (time consumption is reduced to half that of traditional methods, and the amount of quartz sand processed per screening is increased by more than 200%), while controlling dust concentration to ≤1mg / m³. 3 There are no environmental pollution problems.

[0070] The above-mentioned automatic quartz sand screening device optimizes the control parameters of the quartz sand screening control program, and determines the parameters of the vibrating machine according to the following method.

[0071]

[0072] in k For screen stiffness, m For the effective mass of the sand body, ρ p For sand particle density, d p Particle size, μ This refers to the viscosity of air.

[0073] By using a vibration spectrum optimization algorithm, the optimal screening efficiency is determined, and quartz sand is precisely screened, completing the quartz sand screening work with minimal energy consumption.

[0074] Suppose we want to sieve quartz sand with a particle size of 0.5 mm: 1. Known parameters: The screen stiffness k = 5000 N / m (assumed value, the actual value depends on the screen material and structure). The effective mass of the sand body is m = 10 kg (the mass of quartz sand on the sieve). Quartz sand density ρ p =2650kg / m 3 (Typical density of quartz sand) Sand particle size dp=0.5×10 −3 m (target sieve particle size) Air viscosity (air viscosity at room temperature) 2. Calculate the vibration frequency (optimization objective): Calculation of fundamental frequency:

[0075] Calculate the correction term:

[0076]

[0077] Calculate the optimization frequency:

[0078] The correction term in the formula reflects the damping effect of sand density, particle size, and air viscosity on the vibration frequency.

[0079] The optimized frequency (2.04 Hz) is lower than the original resonant frequency (3.56 Hz), indicating that the frequency needs to be reduced to offset the energy loss caused by the interaction between sand particles and air, thereby achieving efficient screening with minimal energy consumption.

[0080] Furthermore, a camera is installed above the quartz sand screen to identify the sand's angle of repose α. The excitation parameters are adjusted based on this angle of repose α. When α < 30°, the vibration frequency of the eccentric mass vibrator is changed, the vibration amplitude is reduced, and the vibration time is extended. In this way, the vibration frequency of the eccentric mass vibrator is precisely controlled according to the sand's angle of repose α, allowing for rapid screening of most of the quartz sand. Then, after screening to a certain extent, the vibration frequency of the eccentric mass vibrator is adjusted and reduced to lower energy consumption, completing the screening with a lower amplitude and further reducing energy consumption.

[0081] The energy consumption of quartz sand screening is calculated to be more than 29% lower than that of traditional quartz sand screening, and the amount of dust pollution during screening is reduced by more than 70%, resulting in a significant improvement in the experimental environment.

[0082] This utility model of an automatic quartz sand screening device improves the screening quality of quartz sand and reduces dust pollution in the experimental environment through innovative features such as structured vibration control and enclosed dust removal. It provides a reliable guarantee for the standardization of materials used in structural physics simulation experiments.

[0083] Example 3 Referring to existing experimental methods, the quartz sand prepared in Example 2 above was processed according to... Figure 3The design diagram of the multi-stage superimposed tectonic process series sand box physical simulation experimental device shown was used for simulation experiments. The quartz sand obtained through sieving in Example 2 above better constructed the quartz sand gradation. Because sieving removed non-target powder and impurities, the quartz sand from multiple sieves was mixed to construct sand layers, resulting in more uniform sand layer density. In the simulated thrust fault experiment, the sand layer changed along the expected path, and the deviation of the fault displacement path due to the density difference of the sand layer was minimal. The fault showed good continuity in the thrust experiment, without any fault breakage or distortion, making the experimental conclusions more reliable.

[0084] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the inventive concept of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment, characterized in that, It includes the following components: a gradient-set screen assembly, a mechanical vibration excitation device, and a vibration control module; The gradient-set screen group includes multiple screens with different mesh sizes, and all screens are set in ascending order of mesh size. The gradient-set screen group consists of screens that can be nested into each other sequentially. Each screen in the gradient-set screen group has an outer frame of the same size, and inspection screens of different mesh sizes are set in the outer frame; the top of the outer frame has at least two slots, and the bottom of the outer frame has a locking block. The screens of adjacent layers are connected to each other to form an integrated structure through the slots and locking blocks of the outer frame. The mechanical vibration excitation device is disposed on the side of the gradient-arranged screen group, and the mechanical vibration excitation device is connected to at least one screen in the screen group. The vibration control module is electrically connected to the mechanical vibration excitation device, and the vibration control module is used to control the mechanical vibration excitation device to vibrate according to a preset frequency and amplitude.

2. The automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 1, characterized in that, The test sieves inside each sieve of the gradient-set sieve group are: 40 mesh standard test sieve, 60 mesh standard test sieve, 80 mesh standard test sieve, and 100 mesh standard test sieve.

3. The automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 2, characterized in that, In the sieve group, the standard test sieve layer spacing between adjacent sieves is 40-80mm.

4. An automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 2 or 3, characterized in that, All test sieves are made of 304 stainless steel.

5. The automatic sand screening device for physical simulation experiment of sand box according to claim 1, characterized in that, The outer frame of the screen is circular.

6. An automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 1 or 5, characterized in that, The inspection sieve is a cylindrical sieve with a diameter of 600-800 mm.

7. The automatic sand screening device for physical simulation experiment of sand box according to claim 5, characterized in that, The multiple standard test sieves of the sieve assembly are provided with annular rubber sealing rings between adjacent layers, and the annular rubber sealing rings have a Shore hardness ≥60HA.

8. The automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 1, characterized in that, The mechanical vibration excitation device is an eccentric mass exciter.

9. The automatic sand screening device for physical simulation experiment of sand box according to claim 1, characterized in that, A partition plate is provided on the side of the screen group with gradient settings. The partition plate is arranged in layers according to the matching of each screen. Each partition plate can divide a screen accordingly, so that the quartz sand on the screen is divided into two parts.

10. The automatic sand screening device for homogeneous quartz sand in a sand box physical simulation experiment according to claim 1, characterized in that, It also includes a negative pressure dust removal unit; the negative pressure dust removal unit is set on the side or above the screen group, and the negative pressure dust removal unit is used to perform negative pressure suction and purification of the dust volatilized by the vibration of the quartz sand on the screen group; the negative pressure dust removal unit includes a cyclone separator, a HEPA filter and a negative pressure fan arranged in series.

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