A device for measuring capillary forces between a floating particle and a solid wall

Abstract

The application relates to a device for measuring capillary force between floating particles and a solid wall surface, comprising a base, a background plate, a measuring cylinder, an overflow bucket, a camera, a light supplement lamp, a water supplement system, a probe fixing system and a wall surface fixing system, the overflow bucket is arranged on the plane base, the measuring cylinder is arranged in the overflow bucket, the measuring cylinder is supplemented with water through a water supplement pipe and a micro flow valve of the water supplement system, the floating particles are fixed by the probe fixing system, light illumination is adjusted by the light supplement lamp, and liquid bridge shape recognition is realized by the camera and image recognition software. The device has the advantages of high measurement precision, simple operation, wide application range and the like, and can be widely applied to the fields of environmental protection, industrial production and scientific research.

Description

Technical Field

[0001] This application relates to the field of ecological and environmental protection, specifically a device for measuring the capillary force between floating particles and a solid wall. Background Technology

[0002] Floating particles are widely present in natural water bodies, especially in wetland ecosystems, lakes, rivers, and oceans. The dispersal process of floating particles has a significant impact on ecological restoration, water flow regulation, and species invasion. Floating particles typically include organic life forms such as plant seeds, fish eggs, larvae, and snails. These particles are often carried by water currents and dispersed in different bodies of water. Studying the movement and settling patterns of floating particles not only helps to understand the migration processes of matter and organisms in ecosystems but also provides a theoretical basis for aquatic ecological protection and wetland restoration.

[0003] Capillary action, a ubiquitous physical phenomenon in nature, plays a crucial role in the interaction between floating particles and their surroundings. Capillary force, caused by surface tension, is the attractive force between floating particles and their surrounding medium (such as the water surface, plant stems, and other floating particles). Specifically, the liquid surface between a solid sidewall and the floating particles often forms a crescent shape. The capillary force in this crescent-shaped liquid surface has both vertical and lateral components. The lateral component encourages the floating particles to move closer together, while the vertical component balances the weight of the liquid, ensuring the stability of the particles' buoyancy. For hydrophilic floating particles (such as plant seeds and fish eggs), when their surface is in contact with the water surface, capillary force further promotes the particles to move towards solid walls (such as stems or banks), forming a clustering phenomenon.

[0004] However, the difficulty in measuring capillary forces lies in the complexity of the shape and morphology of floating particles. Floating particles in nature come in various shapes, including spheres, ellipsoids, and discs, making the calculation of capillary forces challenging. Traditionally, researchers have often simplified particles to standard shapes (such as spheres, ellipsoids, or squares) for analysis, but this method often has significant errors and fails to accurately reflect the actual situation. For example, the capillary force exerted by irregularly shaped particles in contact with a wall differs significantly from that of standard-shaped particles.

[0005] Currently, capillary force measurement typically relies on experimental data or theoretical models, but a simple and reliable method is lacking for measuring irregularly shaped floating particles. Therefore, there is an urgent need for a technical solution that can adapt to floating particles of various shapes and sizes and accurately measure their capillary forces. This technology can not only provide important data support for ecological restoration and water flow regulation, but also provide crucial scientific evidence for the management of invasive non-native species, species dispersal, and aquatic ecosystems.

[0006] In fields such as ecology, climate change, and flow regulation, research on capillary forces between floating particles and water surfaces will provide crucial theoretical support for understanding ecological processes, optimizing ecological restoration programs, and improving water management. As research in this area deepens, precise measurement and analysis methods for capillary forces will have broad application prospects, particularly in ecological environmental protection, agriculture, and aquaculture, helping us better understand and respond to dynamic changes in aquatic ecosystems. Utility Model Content

[0007] The purpose of this application is to provide a device for measuring the capillary force between floating particles and a solid wall, which can solve the problems of complex capillary force measurement methods and insufficient engineering applications.

[0008] To achieve the above objectives, this application provides the following technical solution:

[0009] This application provides a device for measuring the capillary force between floating particles and a solid wall, including a base, a background plate, a measuring cylinder, an overflow tank, a camera, a supplementary light, a water replenishment system, a probe fixing system, and a wall fixing system. The overflow tank is placed on a flat base, and the measuring cylinder is placed inside the overflow tank. Water is replenished to the measuring cylinder through the water replenishment pipe and microfluidic valve of the water replenishment system. The floating particles are fixed by the probe fixing system. The illumination is adjusted by the supplementary light. The shape of the liquid bridge is identified by the camera and image recognition software.

[0010] The base is used to fix the overflow tank and the water supply pipe, and the base is designed as a frame support.

[0011] The background panel is made of high-density polyethylene and is light gray in color to ensure that the background does not reflect during the shooting process and avoids interfering with image quality.

[0012] The measuring cylinder has a diameter of 15-25cm and a height of 20cm. The edges are rounded, and the opening is concave with an angle of 5°-15°. It is coated with a hydrophobic material to effectively prevent liquid from spreading when it comes into contact with the opening, ensuring that a stable convex liquid surface is formed in the middle area of ​​the measuring cylinder, which is convenient for observation and photography.

[0013] The overflow bucket, fixed to the base, has a diameter of 40cm and is used to collect water overflowing from the measuring cylinder, ensuring a stable water level during the measurement process.

[0014] The water supply system uses PVC pipes with a diameter of 4-6mm to transport water. The micro-flow valve of the water supply system is precisely controlled by a PID control valve with an accuracy of ±1% to ensure stable water supply and maintain a stable liquid level in the measuring cylinder.

[0015] The probe fixing system includes a probe embedded in a slider, which moves freely along seven annular slide rails to precisely control the position of the floating particles.

[0016] The wall fixing system uses a fixing frame to fix the solid wall to the bottom of the measuring cylinder. The fixing frame is made of square aluminum alloy and has an aluminum alloy bolt on each side to ensure that the wall is firmly fixed to the bottom of the measuring cylinder, simulating vegetation or a hard wall.

[0017] Compared with existing technologies, the advantages of this invention are: It integrates a high-precision water level regulation and fine-tuning system and a programmable probe positioning mechanism in the same device, enabling precise quantification of capillary forces for irregularly shaped floating particles and various solid walls; it is easy to operate, highly repeatable, and applicable to a wide range of particle materials, sizes, and wall types; it significantly improves data reliability by using a high-resolution camera and image recognition software to collect liquid bridge morphology in real time; and the experimental results can be directly used for optimizing wetland ecological restoration schemes, screening superhydrophobic / superhydrophilic materials, improving microfluidics and membrane separation processes, and... The calibration and verification of the numerical model of interfacial fluid dynamics has broad engineering application and scientific research promotion value. In ecological restoration and water treatment, it can quantitatively assess the capillary action of floating particles (such as plant seeds, fish eggs, snails, etc.) in complex environments, providing technical support for wetland restoration, shoreline vegetation configuration, and pollutant interception. In microfluidics, bioseparation, and membrane separation processes, it can accurately characterize the mechanical parameters of liquid bridges, guiding the screening of superhydrophobic / superhydrophilic materials and process optimization. In interfacial physics and multiphase flow research, the experimental data obtained by this invention can be used to calibrate numerical simulation models such as CFD and DEM. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 Overall layout diagram of the experimental setup

[0020] Figure 2 Design drawing for the bottom of the measuring cylinder

[0021] Figure 3 Cross-sectional view of the measuring cylinder

[0022] Figure 4 Side view of the measurement process

[0023] Figure 5 This is a top view of the measurement process. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. It should be noted that similar reference numerals and letters in the following drawings indicate similar items; therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0025] The terms “comprising,” “including,” or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0026] The terms “first,” “second,” etc., are used only to distinguish one entity or operation from another, and should not be construed as indicating or implying relative importance, nor as requiring or implying any such actual relationship or order between these entities or operations.

[0027] Please see Figure 1 - 5. This utility model provides a device for measuring the capillary force between floating particles and a solid wall, including a base 1, a background plate 11, a measuring cylinder 3, an overflow tank 2, a camera 13, a supplementary light 9, a water replenishment system, a probe fixing system, a wall fixing system 7, etc. The overflow tank 2 is placed on the flat base 1, the measuring cylinder 3 is placed inside the overflow tank 2, the measuring cylinder 3 is replenished with water through the water replenishment pipe 4 and the micro-flow valve 5 of the water replenishment system, the floating particles 18 are fixed by the probe fixing system, the illumination is adjusted by the ring supplementary light strip of the supplementary light 9, the ring supplementary light strip is fixed by the light strip fixing clip 10, and the shape of the liquid bridge 19 is recognized by the camera 13 and image recognition software.

[0028] The base 1 is used to fix the overflow tank 2, the water supply pipe 4, etc. It is made of aluminum alloy and has a frame-type support structure, which can stably fix the overflow tank 2 and the water supply pipe 4, and is easy to assemble and disassemble.

[0029] The background panel 11 is made of high-density polyethylene and is light gray in color to ensure that the background does not reflect during the shooting process and to avoid interfering with image quality.

[0030] The measuring cylinder 3 has a diameter of 15~25cm and a height of 20cm. The edges are rounded, and the opening is slightly concave with an angle of 5°~15°. It is coated with a hydrophobic material to effectively prevent the liquid from spreading when it comes into contact with the opening, ensuring that a stable convex liquid surface 8 is formed in the middle area of ​​the measuring cylinder 3, which is convenient for observation and photography.

[0031] The overflow bucket 2 is fixed on the base 1 and has a diameter of 40cm. It is used to collect the water overflowing from the measuring cylinder 3 to ensure the stability of the water level during the measurement process.

[0032] The water supply pipe 4 of the water supply system is supplied with water through a PVC pipe with a diameter of 4~6mm. The micro-flow valve 5 of the water supply system is precisely controlled by a PID control valve with an accuracy of ±1% to ensure stable water supply and maintain a stable liquid level in the measuring cylinder 3.

[0033] The probe fixing system includes a stainless steel probe 6 with a diameter of 3 mm and a length of 22 cm. The stainless steel probe 6 is embedded in a stainless steel slider 15, which is 1 cm wide and moves freely along seven annular slide rails 17. The annular slide rails 17 are 8 mm wide and are fixedly installed on the upper surface of the bottom plate 14 of the measuring barrel. The three inner annular slide rails are spaced 1 cm apart, and the four outer annular slide rails are spaced 2 cm apart, ensuring that appropriate tracks are selected according to the size of the floating particles 18 to accurately control the position of the floating particles 18.

[0034] The wall fixing system 7 fixes the solid wall to the bottom of the measuring cylinder 3 through the fixing frame 16. The fixing frame is made of square aluminum alloy and is 2cm wide. Each side is equipped with an aluminum alloy bolt to ensure that the wall is firmly fixed to the bottom of the cylinder, simulating vegetation or hard wall.

[0035] The camera 13 is fixedly mounted on the base 1 via a camera bracket 12. The camera 13 uses a zoom lens (24-70mm f / 2.8), has 4K resolution, and is equipped with computer control functions and software. The image recognition software uses OpenCV, which identifies the liquid bridge 19 through threshold segmentation, contour detection, and morphological operations. Edge detection is used to highlight the contour of the liquid bridge 19, and the features of the liquid bridge 19 are further filtered and analyzed using parameters such as area, shape, and position.

[0036] A method for measuring the capillary force between a floating particle and a solid wall includes the following steps:

[0037] (1) Determine the simulated wall surface and floating particles: Floating particles include plant seeds, fish eggs, other organisms, etc., and can be simulated using real particles, water-absorbing biospheres, wood, polycarbonate, etc. Solid walls are generally vegetation or hard walls. Simulated vegetation can be made of soft materials (such as cylinders or sheets made of polyethylene, synthetic rubber, wood, etc.), and hard walls can be simulated using materials such as high-density polyethylene, metal, plexiglass, etc.

[0038] (2) Arrangement and adjustment of measuring needles: Select appropriate measuring needles according to the maximum diameter of the floating particles. If the maximum diameter of the floating particles is less than 3cm, select 3 inner measuring needles for measurement; if the maximum diameter of the floating particles is greater than 3cm, gradually select 4 outer measuring needles. The measuring needles are fixed by a slider and slide rail system, and ensure that the distance between the measuring needles and the floating particles can be accurately adjusted during the measurement process.

[0039] (3) Water replenishment process and water level adjustment: The water flow is adjusted by the PID control valve. First, the water level is raised to 18cm. Then, the small valve is slowly adjusted to continue replenishing water, so that the water level gradually rises to the measuring cylinder opening, with the liquid level slightly higher than the surface of the cylinder opening. This ensures the stability of the liquid level and avoids fluctuations that could affect the formation of liquid bridges.

[0040] (4) Placement of floating particles and adjustment of probe: Slowly place the floating particles on the water surface and use the probe to adjust the position of the floating particles so that they gradually approach the solid wall. Each adjustment distance is about 5mm. Observe the changes in capillary force and use a supplementary light for illumination to ensure that the liquid bridge formation process is clearly visible.

[0041] (5) Liquid bridge formation and photographic recording: After a clear liquid bridge is formed between the floating particles and the solid wall, a high-resolution camera is used to take pictures. The formation process of the liquid bridge is recorded after each probe adjustment. The distance between the floating particles and the wall is gradually reduced. A picture is taken after each adjustment to ensure detailed recording of the morphological changes of the liquid bridge.

[0042] (6) Image Recognition and Data Analysis. OpenCV software was used for image processing and analysis to read the shape parameters of the liquid bridge. The software can automatically identify liquid bridges in images and extract relevant geometric features through algorithms such as edge detection, morphological transformation, and contour analysis. Image processing algorithms combined with a precise pixel coordinate system were used to further quantify the mechanical characteristics of the liquid bridge, providing data support for subsequent calculations of capillary force. Through statistical analysis of multiple measurement data, the functional relationship between capillary force and distance was given. Specific analysis included indicators such as the width, shape, contact angle, and fill angle of the liquid bridge. The calculation formula for the relationship between capillary force and distance is as follows:

[0043]

[0044] In the formula, Fc is the capillary force, dp is the equivalent diameter of the particle, ds is the equivalent diameter of the solid wall, and the equivalent diameter is the diameter of a circle with the same size as the area viewed from above; α p α is the contact angle between the particle and the liquid bridge. s φ is the contact angle between the solid wall and the liquid bridge. p φ is the fill angle between the liquid bridge at the particle end and the horizontal line; φs is the fill angle between the liquid bridge at the solid wall end and the horizontal line. q is the surface tension coefficient; L is the distance between the particle and the solid wall; and q is the capillary force parameter. , ρ w Let ρ be the density of the liquid. a Let g be the air density and g be the acceleration due to gravity.

[0045] The values ​​of capillary tension are shown in the table below.

[0046]

[0047] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A device for measuring the capillary force between floating particles and a solid wall, characterized in that, The system includes a base, a background plate, a measuring cylinder, an overflow tank, a camera, a supplementary light, a water replenishment system, a probe fixing system, and a wall fixing system. The overflow tank is placed on the flat base, and the measuring cylinder is placed inside the overflow tank. Water is replenished to the measuring cylinder through the water replenishment pipe and micro-flow valve of the water replenishment system. Floating particles are fixed using the probe fixing system. Illumination is adjusted using the supplementary light. The shape of the liquid bridge is identified using the camera and image recognition software.

2. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The base is used to fix the overflow tank and the water supply pipe, and the base is designed as a frame support.

3. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The background panel is made of high-density polyethylene and is light gray in color to ensure that the background does not reflect during the shooting process and avoids interfering with image quality.

4. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The measuring cylinder has a diameter of 15-25cm and a height of 20cm. The edges are rounded, and the opening is concave with an angle of 5°-15°. It is coated with a hydrophobic material to effectively prevent liquid from spreading when it comes into contact with the opening, ensuring that a stable convex liquid surface is formed in the middle area of ​​the measuring cylinder, which is convenient for observation and photography.

5. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The overflow bucket, fixed to the base, has a diameter of 40cm and is used to collect water overflowing from the measuring cylinder, ensuring a stable water level during the measurement process.

6. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The water supply system uses PVC pipes with a diameter of 4-6mm to transport water. The micro-flow valve of the water supply system is precisely controlled by a PID control valve with an accuracy of ±1% to ensure stable water supply and maintain a stable liquid level in the measuring cylinder.

7. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The probe fixing system includes a probe embedded in a slider, which moves freely along seven annular slide rails to precisely control the position of the floating particles.

8. The device for measuring the capillary force between floating particles and a solid wall according to claim 1, characterized in that, The wall fixing system uses a fixing frame to fix the solid wall to the bottom of the measuring cylinder. The fixing frame is made of square aluminum alloy and has an aluminum alloy bolt on each side to ensure that the wall is firmly fixed to the bottom of the measuring cylinder, simulating vegetation or a hard wall.

Images