Arch bridge imitating type fixed-point salt collecting interface evaporator and using method and application thereof

Abstract

The invention discloses an arch bridge imitating type fixed-point salt collection interface evaporator and a using method and application thereof, and belongs to the technical field of salt water desalination. The evaporator comprises a heat insulation piece, an evaporation arch bridge is arranged on the heat insulation piece, and arch feet at the two ends of the evaporation arch bridge downwards penetrate out of the heat insulation piece. The system further comprises a salt collecting unit, the salt collecting unit is arranged on the evaporation arch bridge, and when water is evaporated, the transportation path distance from the water to the salt collecting unit is the farthest; the special salt collecting units are additionally arranged on the two sides of the arch bridge, and effective regulation and control of the salt crystallization position are achieved through the design. As the salt collecting unit is farthest from the water body, the salt can be preferentially crystallized and separated out in the area according to the salt concentration gradient distribution principle. The directional crystallization mechanism reduces the local salt concentration of an evaporation interface and effectively inhibits the formation of interface salt crystals, so that the operation stability of the evaporator is remarkably improved.

Description

Technical Field

[0001] This invention relates to an arch-bridge type fixed-point salt collection interface evaporator, its usage method and application, belonging to the field of brine desalination technology. Background Technology

[0002] Seawater desalination technology is currently considered an effective solution to the shortage of freshwater resources, and many desalination strategies have been proposed, such as membrane desalination, electrodialysis, and reverse osmosis. However, the conversion efficiency of these methods is not high. In recent years, novel photothermal driven interfacial evaporators, as a completely new solar brine desalination technology, have attracted much attention due to their simple operation, sustainable operation, environmental friendliness, higher photothermal conversion efficiency, larger scale, and lower cost advantages. They are applicable to brine desalination in various scenarios and have become a research hotspot in the field of brine desalination.

[0003] In recent years, researchers have been dedicated to developing different structures and materials to optimize the efficiency of solar interfacial evaporators. Currently, various photothermal conversion materials and structures applicable to interfacial evaporation have been reported. However, current optimizations of photothermal materials and evaporator structures can only improve the evaporation rate to a limited extent. Furthermore, during seawater desalination, salt in the water is prone to precipitate at the interface due to supersaturation. This precipitated salt can continuously deposit on or inside the evaporator, hindering its performance and stability, and even causing structural damage. Long-term stability of the evaporator is crucial for the large-scale application of solar evaporators. Chinese invention patent application number 202510123440.4 discloses a 3D arched carbon nanotube hollow fiber membrane solar interfacial evaporator, its preparation method, and its application. This solar interfacial evaporator claims to integrate multiple functions such as light absorption, water transport, and salt resistance, featuring fast evaporation speed, high photothermal conversion efficiency, and high stability. However, practical applications have revealed that it still inevitably suffers from the problem of salt precipitating at the interface due to supersaturation, thus hindering the evaporator's performance and stability.

[0004] Therefore, in the practical application of evaporator-based seawater desalination technology, the precipitation and accumulation of salt during the evaporation process has become a key bottleneck restricting its development. Currently, the main methods to improve salt tolerance include reflux, salt barrier, and point-source salt crystallization. However, while reflux and salt barrier can temporarily improve the salt tolerance of the interfacial evaporator, they may produce highly concentrated brine, which contradicts the goal of completely separating salt and water. Therefore, point-source salt crystallization technology has gradually attracted the attention of researchers; despite this, point-source salt collection evaporators are still in their early stages. Summary of the Invention

[0005] (a) Technical problems to be solved The technical problem to be solved by the present invention is to address the issue that salts in water precipitate and accumulate at the interface during the use of existing interfacial evaporators, thereby hindering the performance and stability of the evaporator.

[0006] (II) Technical Solution To address the aforementioned technical problems, this invention provides a simulated arch-bridge type fixed-point salt collection interface evaporator, including a heat insulation component. An evaporation arch bridge is mounted on the heat insulation component (the arch shape creates a temperature gradient between the upper and lower parts of the evaporation arch bridge, which can achieve certain thermal management, thereby promoting improved evaporation performance). The arched ends of the evaporation arch bridge extend downwards through the heat insulation component; the arch shape creates a temperature gradient between the upper and lower parts of the evaporation arch bridge. It also includes a salt collection unit, which is located on the evaporation arch bridge. During water evaporation, the transport path from the water to the salt collection unit is the longest. The theoretical basis of this design is the distribution law that the salt concentration in water increases with the increase of the water transport distance. By extending the water transport path, the crystallization sequence of salt is changed. Since the salt collection unit is farthest from the water, salt will preferentially crystallize and precipitate in this area. This preferential crystallization mechanism effectively reduces the salt concentration at the evaporation interface of the evaporation arch bridge, thereby inhibiting the formation of salt crystals at the evaporation interface of the evaporation arch bridge. This targeted salt collection method not only achieves controlled salt deposition but also significantly improves the operational stability of the evaporator. This design cleverly utilizes the spatial distribution characteristics of salt crystallization, providing an innovative solution to the problem of salt deposition in traditional evaporators.

[0007] Furthermore, the salt collection unit is installed on the evaporation arch bridge above the heat insulation component. The salt collection unit is located on the side of the evaporation arch bridge, which makes it easier to install. The salt collection unit is installed on both sides of the evaporation arch bridge to provide sufficient salt collection area.

[0008] Furthermore, the salt collection units are respectively set on both sides of the top of the evaporation arch bridge. The salt collection units are set at the highest point of the evaporation arch bridge so that the water can form the longest transportation path more quickly when it reaches the salt collection units. Furthermore, the salt collection unit adopts a sheet-like structure, which extends from the top of the evaporation arch bridge to both sides and hangs on both sides of the top of the evaporation arch bridge, which helps the salt to fall off automatically.

[0009] Furthermore, both the evaporation arch bridge and the salt collection unit are made of photothermal fabric, which is composed of non-woven fabric, biochar and sodium alginate. It has the characteristics of low cost and can realize the recycling of waste biomass resources.

[0010] Furthermore, the evaporation arch bridge and the salt collection unit are integrally formed, which is convenient to manufacture, and the evaporation arch bridge can be directly cut.

[0011] Furthermore, the photothermal fabric is made by cross-linking a nonwoven fabric impregnated with biochar and sodium alginate.

[0012] Furthermore, the bending angle of the evaporation arch is 45 to 180° to ensure good evaporation effect.

[0013] This invention also provides a method for using the aforementioned arch-bridge type fixed-point salt collection interface evaporator. In use, it is placed at the water body to be treated, with the insulation component positioned on top of the water. The two arched ends of the evaporation arch extend downwards from the insulation component and into the water body. Water in the water body is transported and evaporated along the evaporation arch and the salt collection unit. Salt preferentially accumulates in the salt collection unit, and the salt crystals in the salt collection unit are periodically treated. This directional crystallization mechanism reduces the local salt concentration at the evaporation interface, effectively inhibiting the formation of interface salt crystals, thereby significantly improving the operational stability of the evaporator.

[0014] This invention also provides the application of the above-described arch-bridge type fixed-point salt collection interface evaporator in water purification, including its application in the treatment of saline organic wastewater, seawater desalination, and saline-alkali land improvement.

[0015] (III) Beneficial Effects The above-described technical solution of the present invention has the following advantages: This invention adds specialized salt collection units (drooping structures) on both sides of the central apex of the evaporation arch, a design that effectively controls the location of salt crystallization. Since the salt collection area (salt collection unit) is furthest from the water body, salt will preferentially crystallize and precipitate in this area according to the principle of salt concentration gradient distribution. This directional crystallization mechanism reduces the local salt concentration at the evaporation interface of the evaporation arch, effectively inhibiting the formation of interfacial salt crystals, thereby significantly improving the operational stability of the evaporator.

[0016] In addition to the technical problems solved by the present invention, the technical features of the technical solutions constituted by the present invention, and the advantages brought about by the technical features of these technical solutions as described above, other technical features of the present invention and the advantages brought about by these technical features will be further explained in conjunction with the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure and working principle of a traditional arch bridge type interface evaporator (ABE) (top view).

[0019] Figure 2 This is a schematic diagram of the structure and working principle of the fixed-point salt collection arch bridge type interface evaporator (SC-ABE) of the present invention.

[0020] Figure 3 This is a schematic optical diagram of the interface during the evaporation of 3.5 wt% brine in a conventional arch-bridge type interface evaporator.

[0021] Figure 4 Infrared schematic diagram of the interface temperature change during the evaporation of 3.5 wt% brine in a conventional arch-bridge type interface evaporator.

[0022] Figure 5 This is a schematic optical diagram of the interface during the evaporation of 3.5 wt% brine using the interface evaporator of the present invention.

[0023] Figure 6 This is an infrared schematic diagram showing the interface temperature change during the evaporation of 3.5 wt% brine using the interface evaporator of the present invention.

[0024] Figure 7 This diagram illustrates the salt ion concentration distribution in a conventional arch-bridge type interface evaporator used for theoretical simulation of photothermal evaporation.

[0025] Figure 8 This is a schematic diagram of the salt ion concentration distribution of the interfacial evaporator of this invention, used for theoretical simulation of photothermal evaporation. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1 like Figure 1The image shows a simulated arch bridge type fixed-point salt collection interface evaporator, comprising a heat insulation component with an evaporation arch bridge (which can also be wavy) mounted on it. The curvature angle of the evaporation arch bridge is 45°–180°, for example, 45°, 60°, 90°, 120°, 160°, or 180°. The arch feet at both ends of the evaporation arch bridge extend downwards through the heat insulation component. It also includes sheet-like salt collection units mounted on the evaporation arch bridge above the heat insulation component, with salt collection units positioned on both sides of the top of the evaporation arch bridge. The salt collection units extend from the top of the evaporation arch bridge to both sides and hang vertically on both sides of the top of the evaporation arch bridge (the salt collection units can also be located in other positions, such as the middle of the bottom of the bridge, and may not hang vertically, for example, slightly inclined).

[0028] In this embodiment, the evaporation arch and the salt collection unit are integrally molded structures, typically unfolded into a cross-shaped structure, and can be cut to size. Both the evaporation arch and the salt collection unit are made of photothermal fabric, which is composed of non-woven fabric, biochar, and sodium alginate. Specifically, the photothermal fabric is made by cross-linking non-woven fabric impregnated with biochar and sodium alginate.

[0029] In this embodiment, the heat insulation component can be heat insulation foam.

[0030] Example 2 The difference between this embodiment and embodiment 1 is that the arch-shaped fixed-point salt collection interface evaporator further includes a container containing water to be treated, and the heat insulation component is disposed on the upper port of the container.

[0031] Example 3 This embodiment provides a method for using the simulated arch bridge type fixed-point salt collection interface evaporator described in Embodiment 1 above. In use, it is placed at the water body to be treated, with the heat insulation component positioned on the water body, and the two arched ends of the evaporation arch bridge extending downwards from the heat insulation component and into the water body. Water in the water body is transported and evaporated along the evaporation arch bridge and the salt collection unit, with salt preferentially accumulating in the salt collection unit. The salt crystals in the salt collection unit are periodically treated. This can be achieved by setting a hydrophilic / hydrophobic structure in the salt collection unit to automatically remove salt crystals, setting an auxiliary removal structure to periodically scrape off the crystals on the salt collection unit, or by manual periodic scraping.

[0032] Example 4 This embodiment provides the application of the arch-bridge-type fixed-point salt collection interface evaporator described in the above embodiments in water purification, including its application in the treatment of saline organic wastewater, seawater desalination, and saline-alkali land improvement. Specifically, when applied to saline-alkali land improvement, placing the evaporator in a supporting treatment device promotes the migration of salt from the soil to the evaporator surface, where it crystallizes in the salt collection area. Simultaneously, the condensate generated during evaporation can be used for continuous purification of the saline-alkali land, thereby achieving soil improvement and salt resource recovery.

[0033] Experimental Example 1 like Figure 1-2 As shown in the diagrams, two schematic diagrams compare the structural differences and working principles of the traditional arch-bridge type interfacial evaporator (ABE) and the fixed-point salt collection arch-bridge type interfacial evaporator (SC-ABE) of this application. The mechanism by which SC-ABE achieves fixed-point salt collection and inhibits interfacial salt crystallization is mainly based on its unique structural design. Compared with ABE, SC-ABE adds salt collection units (salt collection areas, the hanging parts) on both sides of the top of the evaporation arch. This design changes the crystallization sequence of salt by extending the water transport path. Since the salt collection area of ​​the salt collection unit is farthest from the water body, salt will preferentially crystallize and precipitate in this area. This preferential crystallization mechanism effectively reduces the salt concentration at the evaporation interface of the evaporation arch, thereby inhibiting the formation of interfacial salt crystals. Through this fixed-point salt collection method, SC-ABE not only achieves controllable salt deposition but also significantly improves the operational stability of the evaporator. This design cleverly utilizes the spatial distribution characteristics of salt crystallization, providing an innovative solution to the problem of salt deposition in traditional evaporators.

[0034] Experiment Example 2 The interfacial changes during the evaporation of 3.5 wt% brine using conventional ABE were observed experimentally. Figure 3 As shown in the figure, the experimental results indicate that salt crystallization begins to occur on the evaporator surface after 2 hours of evaporation. The formation of salt crystals not only reduces light absorption efficiency but also significantly hinders steam escape. This conclusion is supported by the following... Figure 4 Further confirmation is shown. Infrared imaging analysis of the interface temperature changes of a conventional ABE at different time points revealed an accelerated upward trend in interface temperature after the 2nd hour. This phenomenon can be attributed to the obstruction of steam escape caused by salt crystallization, which weakens the steam convection heat dissipation effect, causing heat to accumulate at the interface and thus leading to an increase in interface temperature. In summary, the experimental results indicate that conventional ABE has significant limitations in treating brine. As the evaporation process proceeds, salt crystals easily form on the evaporation surface, leading to a significant decrease in evaporator stability.

[0035] The interfacial changes of SC-ABE during the evaporation of 3.5 wt% brine were observed experimentally. Figure 5 As shown, experimental results indicate that no salt crystallization occurred at the photothermal interface of SC-ABE, fully demonstrating that SC-ABE exhibits superior stability compared to ABE. Figure 6 As shown, infrared imaging analysis of the SC-ABE interface temperature changes at different time points revealed that after 1 hour of evaporation, the interface temperature remained stable at around 39.6℃, without any significant temperature increase. Combined with... Figure 5The results show that this is because no salt crystals formed at the interface, thus the interface temperature remained stable.

[0036] Experimental Example 3 To verify the theoretical basis for SC-ABE to achieve fixed-point salt collection. For example... Figure 7-8 The theoretical simulations performed using COMSOL were shown to investigate the salt ion distribution characteristics on the evaporator surface during photothermal evaporation. The simulation results indicate that, as... Figure 7 As shown, in the traditional ABE system, the evaporation process leads to a significant accumulation of salt ion concentration at the top of the arch (the furthest point of water supply), and the high-concentration area gradually expands towards the evaporation interface, eventually forming a large area of ​​high salt concentration. In contrast, the SC-ABE system exhibits unique salt distribution characteristics, such as... Figure 8 As shown, with the progress of evaporation, the salt-collecting unit, being located at the farthest point, becomes the main area of ​​salt enrichment. This salt enrichment effectively reduces the salt concentration at the evaporation interface, thus significantly inhibiting salt crystallization. The simulation results show good agreement with experimental observation data, verifying the reliability of the model.

[0037] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A simulated arch bridge type fixed-point salt collection interface evaporator, comprising a heat insulation component, wherein an evaporation arch bridge is provided on the heat insulation component, and the arched feet at both ends of the evaporation arch bridge extend downward through the heat insulation component; characterized in that: It also includes a salt collection unit, which is set on the evaporation arch bridge. When water evaporates, the transport path of the water to the salt collection unit is the longest.

2. The arch-bridge type fixed-point salt collection interface evaporator according to claim 1, characterized in that: The salt collection unit is installed on the evaporation arch bridge located above the heat insulation component. The salt collection unit is located on the side of the evaporation arch bridge, and the salt collection unit is installed on both sides of the evaporation arch bridge.

3. The arch-bridge type fixed-point salt collection interface evaporator according to claim 2, characterized in that: The salt collection units are respectively installed on both sides of the top of the evaporation arch bridge.

4. The arch-bridge type fixed-point salt collection interface evaporator according to claim 3, characterized in that: The salt collection unit adopts a sheet-like structure, which extends from the top of the evaporation arch bridge to both sides and hangs down on both sides of the top of the evaporation arch bridge.

5. The arch-bridge type fixed-point salt collection interface evaporator according to claim 1, characterized in that: Both the evaporation arch bridge and the salt collection unit are made of photothermal fabric, which is composed of non-woven fabric, biomass carbon and sodium alginate.

6. The arch-bridge type fixed-point salt collection interface evaporator according to claim 5, characterized in that: The evaporation arch bridge and the salt collection unit are integrally formed.

7. The arch-bridge type fixed-point salt collection interface evaporator according to claim 6, characterized in that: The photothermal fabric is made by cross-linking a nonwoven fabric impregnated with biochar and sodium alginate.

8. The arch-bridge type fixed-point salt collection interface evaporator according to claim 7, characterized in that: The bending angle of the evaporation arch bridge is 45 to 180°.

9. The method of using the arch-bridge type fixed-point salt collection interface evaporator according to any one of claims 1-8, characterized in that: When in use, it is placed at the water body to be treated, with the heat insulation component placed on the water body and the two ends of the evaporation arch extending downwards into the water body. The water in the water body is transported and evaporated along the evaporation arch and the salt collection unit. Salt is preferentially enriched in the salt collection unit, and the salt crystals in the salt collection unit are treated periodically.

10. The application of the arch-bridge type fixed-point salt collection interface evaporator according to any one of claims 1-8 in water purification, including its application in the treatment of saline organic wastewater, seawater desalination, and saline-alkali land improvement.

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