A high-speed fog collection method based on the phenomenon of self-driven water jets of micro-droplets
By designing superhydrophobic and superhydrophilic pore array structures on the mist collector, and using the phenomenon of micro-fog droplets to drive water jets, the problem of low mist collection rate is solved, and efficient mist collection is achieved.
Patent Information
- Application Number
- CN202310103772.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-02-13
- Publication Date
- 2025-07-22
- Estimated Expiration
- 2043-02-13
AI Technical Summary
The existing mist collection methods have the problem of low mist collection rate, which is difficult to meet the need for efficient water acquisition.
The inner and outer surfaces of the mist collector are superhydrophobic and superhydrophilic pore array structures respectively. The micro-fog droplets are used to drive the water jet phenomenon, and the micro-fog droplets enter the inside of the mist collector through Laplace pressure to form a water jet to achieve efficient collection.
It achieves a high frequency of small droplets falling off, an increased fog collection rate, and does not rely on gravity to adapt to different fog flow environments.
Smart Images
Figure CN116358930B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of fog collection, and mainly relates to a high-speed fog collection method based on the self-driven water jet phenomenon of micro fog droplets. Background Art
[0002] Fog is a common natural phenomenon, and there is as much as 1.3 million trillion liters of water existing in the atmosphere in the form of fog or water vapor. In order to solve the problem of shortage of fresh water resources on the earth, scientific researchers have proposed to obtain water sources from the atmosphere through fog collection methods. In 2001, Andrew et al. from the University of Oxford showed that the Namib Desert beetle has excellent spontaneous fog collection ability due to its patterned surface with hydrophilic and hydrophobic regions on its back (Nature 2001, 414, 33 - 34). Since then, scientific researchers have developed a series of nature-inspired fog collection methods. Almost all nature-inspired fog collection methods can be divided into the following five types: the wettability-patterned surface inspired by the Namib Desert beetle (Nature 2001, 414, 33 - 34), the composite surface with a combination of structural gradient and wettability gradient inspired by spider silk (Nature 2010, 463, 640 - 643), the composite surface with a combination of structural gradient and wettability gradient inspired by cactus spines (Nature communications 2012, 3, 1247), the Janus surface inspired by lotus leaves (Small 2015, 11, 4379 - 4384), and the slippery surface inspired by Nepenthes (Nature 2016, 531, 78 - 82). Among them, the Janus surface inspired by lotus leaves transports the fog droplets captured on the superhydrophobic side to the superhydrophilic side relying on the wettability gradient on the surface; compared with the other four fog collection methods, the fog collection rate of the Janus surface is the highest. However, the water collected by the Janus surface finally converges on one side of the superhydrophilic surface, and the collected water adheres to the superhydrophilic surface and is difficult to detach from the surface, resulting in the difficulty of further improving the fog collection rate. For fog with a certain flow rate, the droplet shedding frequency directly determines the fog collection rate. However, all of the above methods rely on gravity to drive the shedding of millimeter-sized droplets for collection, so the shedding frequency of the collected droplets from the collection surface is low, and it is very difficult to further improve the fog collection rate.
[0003] In summary, the existing fog collection methods have the problem of low fog collection rate, and it is difficult to meet the demand for efficiently obtaining water from fog. Therefore, it is necessary to develop a method that can collect water from fog at high speed. Summary of the Invention
[0004] The purpose of the present invention is to address the problem of low fog collection rate existing in the above-mentioned fog collection methods, and propose a high-speed fog collection method based on the self-driven water jet phenomenon of micro fog droplets.
[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:
[0006] A high-speed fog collection method based on the self-driven water jet phenomenon of micro-droplets, mainly realized by a fog collector 1 and internal water 2.
[0007] The fog collector 1 is a hollow metal cuboid structure with an open top, and the wall thickness of the hollow metal cuboid structure is 0.1 mm to 0.5 mm; the inner and outer surfaces of the metal cuboid structure are sequentially obtained with superhydrophobicity through laser etching and low surface energy modification, and the contact angles of water droplets on both sides of its surface are greater than 150°; and through the method of laser etching, a through-hole array with a diameter of 0.1 mm to 1 mm and a hole center spacing of 0.5 mm to 2 mm is processed at equal intervals on the superhydrophobic surface, and the surface of the processed holes has superhydrophilicity, and the contact angle of water droplets on the surface of the holes is less than 10°; according to the size of the diameter of the superhydrophilic holes 4, the height of the fog collector is 5 mm to 11 mm. Water 2 is injected into the fog collector 1, and thus a fog collector capable of performing the fog collection function is formed.
[0008] The fog collector 1 filled with water 2 is placed in the fog flow. The outer surface of the fog collector 1 can easily capture the tiny fog droplets 5 in the fog flow. The tiny fog droplets 5 grow and merge on the outer surface of the fog collector 1 to form sub-millimeter-sized micro-droplets 6; due to the superhydrophilicity of the holes on the fog collector 1, the water 2 inside the fog collector 1 will wet the superhydrophilic holes 4. Once the micro-droplets 6 come into contact with the superhydrophilic holes 4 on the fog collector 1, they will form a whole with the water 2 inside the fog collector 1. The micro-droplets 6 will enter the inside of the fog collector 1 under the action of the internal Laplace pressure and generate a water jet; in addition, the micro-droplets 6 will also merge with other micro-droplets 7 around the superhydrophilic holes 4 during the process of entering the inside of the fog collector 1 and enter the inside of the fog collector 1 together. Therefore, this fog collection method based on the self-driven water jet phenomenon of micro-droplets has a small droplet detachment size and a high droplet detachment frequency, making it have a high fog collection rate.
[0009] Furthermore, the larger the diameter of the superhydrophilic holes 4 on the fog collector 1, the smaller the height of the fog collector 1.
[0010] Compared with the existing fog collection methods, the present invention has the following beneficial effects:
[0011] (1) In the present invention, there is no need to wait for the droplets to grow to millimeter-sized to detach from the fog collection surface as in the previous fog collection literature, and the droplet detachment frequency is low; instead, when they reach the sub-millimeter size, they will detach from the surface of the fog collector and be collected by the fog collector. Therefore, it has a high droplet detachment frequency, making the fog collection rate of this fog collection method high.
[0012] (2) The fog collection method proposed by the present invention does not rely on gravity to shed the micro-droplets captured on the surface, but uses the Laplace pressure inside the micro-droplets for driving. The micro-droplets can spontaneously and rapidly enter the fog collector and generate a water jet.
[0013] (3) During the process of the micro-droplets entering the inside of the fog collector in the present invention, they will also merge with other droplets around the super-hydrophilic pores and enter the inside of the fog collector together.
[0014] (4) The present invention can design the size of the fog collector, the size of the super-hydrophilic pores and the pore spacing to adapt to fog environments with different flow rates, so as to achieve the best fog collection effect. Brief Description of the Drawings
[0015] Figure 1 is a schematic diagram of a high-speed fog collector based on the self-driven water jet phenomenon of micro-droplets;
[0016] Figure 2 is a process diagram of the micro-droplets captured on the surface of the fog collector entering the fog collector;
[0017] Figure 3 is a process diagram of a single stained micro-droplet entering the inside of the fog collector through the super-hydrophilic pores on the surface of the fog collector and generating a water jet;
[0018] Figure 4 is the fog collection of a high-speed fog collector based on the self-driven water jet phenomenon of micro-droplets in a stained artificial fog flow; the micro-droplets captured by the fog collector enter the inside of the fog collector under the action of the Laplace pressure and generate multiple water jets.
[0019] In the figure: 1 fog collector; 2 water inside; 3 super-hydrophobic surface; 4 super-hydrophilic pores; 5 tiny fog droplets; 6 micro-droplets; 7 micro-droplets around the super-hydrophilic pores. Detailed Embodiments
[0020] The following further describes the detailed embodiments of the present invention in conjunction with the drawings.
[0021] Embodiment 1
[0022] A high-speed fog collection method based on the self-driven water jet phenomenon of micro-droplets is composed of a fog collector 1 and water 2 inside the fog collector. The inner and outer surfaces of the fog collector 1 are both super-hydrophobic aluminum surfaces, and their super-hydrophobicity is obtained by laser etching and low surface energy modification. The contact angle of water droplets on its surface is greater than 150°. Then, super-hydrophilic pores 4 with a diameter of 0.2 mm and a center-to-center pore spacing of 1.2 mm are processed at equal intervals on the super-hydrophobic aluminum surface 3 by laser etching. The surface of the processed pores has super-hydrophilicity, and the contact angle of water droplets on its pore surface is less than 10°. Then, water 2 is injected into the inside of the fog collector 1, thus constituting a high-speed fog collector based on the self-driven water jet phenomenon of micro-droplets.
[0023] Place this fog collector in the fog flow. The process of micro-fog droplets 6 entering the fog collector 1 is as follows Figure 2 shown. The superhydrophobic surface 3 of the fog collector 1 easily captures the tiny fog droplets 5 in the fog flow. The tiny fog droplets 5 grow and merge on the superhydrophobic surface 3 to form sub-millimeter-sized micro-fog droplets 6. Since the holes on the fog collector 1 are superhydrophilic, the water 2 inside the fog collector 1 will wet the superhydrophilic holes 4. Once the micro-fog droplet 6 comes into contact with the superhydrophilic hole 4 on the fog collector 1, it will form a whole with the water 2 inside the fog collector 1. The micro-fog droplet 6 will enter the inside of the fog collector 1 under the action of the internal Laplace pressure and generate a water jet. In addition, during the process of the micro-fog droplet 6 entering the inside of the fog collector 1, it will also merge with the micro-liquid droplets 7 around the superhydrophilic hole 4 and enter the inside of the fog collector 1 together, and form a water jet phenomenon as shown in Figure 3 and Figure 4 shown. Through the fog collection experiment, the fog collection rate of the fog collector under the parameters of this hole array is measured to be 2.86 g·cm -2 ·h -1 .
[0024] Comparative Example 1
[0025] A superhydrophobic fog collector with superhydrophilic holes is as shown in Figure 1 shown, and it is composed of the fog collector 1. The inner and outer surfaces of the fog collector 1 are both superhydrophobic aluminum surfaces, and their superhydrophobicity is obtained after laser etching and low surface energy modification. The contact angle of water droplets on its surface is greater than 150°. Then, by means of laser etching, superhydrophilic holes 4 with a diameter of 0.2 mm and a center distance of 1.2 mm are processed at equal intervals on the superhydrophobic aluminum surface 3. The surface of the processed holes is superhydrophilic, and the contact angle of water droplets on the hole surface is less than 10°.
[0026] Place this unwatered fog collector in the fog flow. The superhydrophobic surface 3 of the fog collector 1 easily captures the tiny fog droplets 5 in the fog flow. The tiny fog droplets 5 grow and merge on the superhydrophobic surface 3 to form sub-millimeter-sized micro-fog droplets 6. Although the superhydrophilic holes 4 on the fog collector 1 will also capture the micro-liquid droplets 6, since there is no water inside the fog collector 1, the micro-liquid droplets 6 will not generate an internal Laplace pressure, so they cannot be transported from the outer surface of the fog collector 1 to the inside of the fog collector 1. The collection rate of this unwatered fog collector is 0 g·cm -2 ·h -1 .
[0027] Example 2
[0028] A high-efficiency fog collector based on self-driven water jets of micro-fog droplets is as shown in Figure 1As shown in the figure, it consists of a fog collector 1 and water 2 inside the fog collector. The inner and outer surfaces of the fog collector 1 are both superhydrophobic aluminum surfaces, and their superhydrophobicity is obtained by laser etching and low surface energy modification. The contact angle of water droplets on its surface is greater than 150°. Then, by means of laser etching, superhydrophilic holes 4 with a diameter of 0.4 mm and a center distance of 1.3 mm are processed at equal intervals on the superhydrophobic surface 3. The surface of the processed holes has superhydrophilicity, and the contact angle of water droplets on the hole surface is less than 10°. Then, water 2 is injected into the inside of the fog collector 1, thus constituting a high-speed fog collector based on the self-driven water jet phenomenon of micro-mist droplets.
[0029] When the fog collector is placed in the fog flow, the process of micro-mist droplets 6 entering the fog collector 1 is as Figure 2 shown. The superhydrophobic surface 3 of the fog collector 1 can easily capture the tiny fog droplets 5 in the fog flow. The tiny fog droplets 5 grow and merge on the superhydrophobic surface 3 to form sub-millimeter-sized micro-mist droplets 6. Since the holes on the fog collector 1 have superhydrophilicity, the water 2 inside the fog collector 1 will wet the superhydrophilic holes 4. Once the micro-mist droplets 6 come into contact with the superhydrophilic holes 4 on the fog collector 1, they will form a whole with the water 2 inside the fog collector 1. The micro-mist droplets 6 will enter the inside of the fog collector 1 under the action of the internal Laplace pressure and generate a water jet. In addition, during the process of the micro-mist droplets 6 entering the inside of the fog collector 1, they will also merge with the micro-liquid droplets 7 around the superhydrophilic holes 4 and enter the inside of the fog collector 1 together, and form a water jet phenomenon as shown in Figure 3 and Figure 4 shown. Through the fog collection experiment, the fog collection efficiency of the fog collector under the parameters of this hole array is measured to be 4.01 g·cm -2 ·h -1 .
[0030] Example 3
[0031] A high-efficiency fog collector based on the self-driven water jet of micro-mist droplets is as Figure 1 shown, consisting of a fog collector 1 and water 2 inside the fog collector. The inner and outer surfaces of the fog collector 1 are both superhydrophobic aluminum surfaces, and their superhydrophobicity is obtained by laser etching and low surface energy modification. The contact angle of water droplets on its surface is greater than 150°. Then, by means of laser etching, superhydrophilic holes 4 with a diameter of 0.8 mm and a center distance of 1.7 mm are processed at equal intervals on the superhydrophobic surface 3. The surface of the processed holes has superhydrophilicity, and the contact angle of water droplets on the hole surface is less than 10°. Then, water 2 is injected into the inside of the fog collector 1, thus constituting a high-speed fog collector based on the self-driven water jet phenomenon of micro-mist droplets.
[0032] When the fog collector is placed in the fog flow, the process of micro-mist droplets 6 entering the fog collector 1 is as Figure 2As shown, the superhydrophobic surface 3 of the fog collector 1 easily captures the tiny fog droplets 5 in the fog flow. The tiny fog droplets 5 grow and merge on the superhydrophobic surface 3 to form sub-millimeter-sized micro-fog droplets 6. Since the holes on the fog collector 1 are superhydrophilic, the water 2 inside the fog collector 1 will wet the superhydrophilic holes 4. Once the micro-fog droplets 6 come into contact with the superhydrophilic holes 4 on the fog collector 1, they will form a whole with the water 2 inside the fog collector 1. The micro-fog droplets 6 will enter the inside of the fog collector 1 under the action of the internal Laplace pressure and generate a water jet. In addition, during the process of entering the inside of the fog collector 1, the micro-fog droplets 6 will also merge with the micro-liquid droplets 7 around the superhydrophilic holes 4 and enter the inside of the fog collector 1 together, and form a water jet phenomenon as shown in Figure 3 and Figure 4 . Through the fog collection experiment, the fog collection efficiency of the fog collector under the parameters of this hole array is measured to be 3.41 g·cm -2 ·h -1 .
[0033] The above-described embodiments only represent the implementation modes of the present invention, but should not be construed as limiting the scope of the patent for the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.
Claims
1. A high-speed fog collection method based on the self-driven water jet phenomenon of micro-droplets, characterized in that, The described high-speed fog collection method is implemented by a high-speed fog collector, which includes a fog collector (1) and internal water (2). The fog collector (1) is a hollow metal cuboid structure with an open top, a wall thickness of 0.1 mm to 0.5 mm, and both the inner and outer surfaces exhibit superhydrophobicity with a contact angle greater than 150°. There is also a superhydrophilic through-hole array with a diameter of 0.1 mm to 1 mm and a hole center spacing of 0.5 mm to 2 mm on both the inner and outer surfaces. The contact angle of water droplets on the superhydrophilic holes is less than 10°. The height of the fog collector (1) is 5 mm to 11 mm. Water (2) is injected into the fog collector (1), and thus a high-speed fog collector is obtained. The obtained high-speed fog collector is placed in a fog flow. The outer surface of its fog collector (1) can capture tiny fog droplets (5) in the fog flow. The tiny fog droplets (5) grow and merge on the outer surface of the fog collector (1) to form sub-millimeter-sized micro-fog droplets (6). Due to the superhydrophilicity of the holes on the fog collector (1), the internal water (2) in the fog collector (1) will wet the superhydrophilic holes (4). Once the micro-fog droplets (6) come into contact with the superhydrophilic holes (4) on the fog collector (1), they will form a whole with the internal water (2) in the fog collector (1). The micro-fog droplets (6) will enter the interior of the fog collector (1) under the action of the internal Laplace pressure and generate a water jet. In addition, the micro-fog droplets (6) will also merge with other micro-fog droplets (7) around the superhydrophilic holes (4) during the process of entering the interior of the fog collector (1) and enter the interior of the fog collector (1) together, finally completing the fog collection.