Solar interface seawater desalination multi-stage distiller
By combining a multi-stage distillation design with a hydrophobic modified light-transmitting layer, photothermal materials, and a hydrophobic condenser plate, the problems of low heat utilization and large size of existing solar stills have been solved, achieving efficient freshwater production and convenient seawater desalination.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-28
- Publication Date
- 2026-03-03
AI Technical Summary
Existing solar stills are inadequate in terms of latent heat recovery from steam condensation and energy conversion efficiency. Furthermore, the devices are large, inconvenient to carry, and difficult to set up easily in different environments.
It adopts a multi-stage distillation design, including a first-stage distillation body, a second-stage distillation body, a third-stage distillation body, and a fixing layer. It utilizes a transparent hydrophobic layer modified with a light-transmitting layer, photothermal materials, and a hydrophobic condenser plate, which are fixedly connected by screw holes to achieve heat transfer and condensation in stages. Combined with a peristaltic pump and hoses to deliver brine, it simplifies the operation process.
It improves heat utilization and freshwater production, has a compact structure that is easy to carry, is suitable for various scenarios, ensures the continuity and stability of the distillation process, and reduces heat loss and freshwater retention.
Smart Images
Figure CN223963299U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of seawater desalination technology, and in particular to a solar-powered interface seawater desalination multi-stage distillation apparatus. Background Technology
[0002] Freshwater scarcity has become an urgent challenge to the sustainable development of human society, and one promising strategy to effectively solve this problem is to fully utilize the Earth's abundant seawater resources for desalination. However, traditional seawater desalination technologies often require the participation of electricity and chemical energy, which not only causes energy consumption but also triggers a series of problems such as the greenhouse effect and environmental pollution. In recent years, researchers have begun to study seawater desalination devices based on renewable energy sources, introducing solar energy into the field of seawater desalination. However, existing solar distillers still have the following problems in use:
[0003] To achieve efficient distilled water collection, there are currently three main types of solar-powered distiller technologies:
[0004] The first type is a detachable two-stage solar distiller (such as...). Figure 8 As shown in the figure, it mainly consists of a second-stage still, a first-stage still, a still base, and a water collection module. This separate structure has the problem that water vapor easily condenses into a liquid film on the hydrophilic condenser wall of the second stage, reducing light absorption and resulting in low heat utilization of the two-stage separate structure.
[0005] Another type is a unidirectional heat transfer solar distiller that does not require disassembly (such as...). Figure 9 As shown, the still includes a distillation body and a condenser, wherein the distillation body is composed of a sealed body, an interfacial evaporation material, and a light-transmitting body. This type of still can use materials with a large evaporation area and can obtain more fresh water, but it is not convenient to change the water source, and in order to reduce heat loss, it needs to be fixed with tools. It is also large and heavy, making it inconvenient to carry around, and has certain limitations.
[0006] The last type is a multi-stage solar distiller with self-storing water on the back (such as...). Figure 10 As shown in the diagram, this device uses solar energy to heat seawater and produce freshwater. The multi-stage solar distiller is coaxially arranged, with a horizontal cylindrical hot water storage tank at the center. The evaporation and condensation walls surrounding the tank are semi-cylindrical, with vacuum tube solar collectors located on the lower semi-cylindrical surface. While this device can operate stably for extended periods, to ensure concentrated heat from the storage tank, the distiller is generally large. Furthermore, to minimize heat loss, the device needs to be securely fixed, making it unsuitable for simple setup and water source placement. Additionally, the glass walls of this distiller are prone to fogging from fine water vapor, significantly reducing solar transmittance and impacting water collection rate and solar energy utilization efficiency.
[0007] To address the aforementioned problems, this utility model proposes a solar-powered interface seawater desalination multi-stage distillation apparatus. Utility Model Content
[0008] The purpose of this invention is to address the shortcomings of conventional solar stills in the prior art, such as difficulty in fully recovering the latent heat of water vapor condensation and low energy conversion efficiency, and to propose a solar interface seawater desalination multi-stage still.
[0009] To achieve the above objectives, the present invention adopts the following technical solution:
[0010] A solar-powered interfacial seawater desalination multi-stage distillation apparatus includes:
[0011] The first-stage distillation body, the second-stage distillation body, the third-stage distillation body, and the stationary layer;
[0012] The first-stage distillation body, the second-stage distillation body, and the third-stage distillation body are all composed of a water inlet layer, a hydrophobic film, a drainage layer, and a condenser plate;
[0013] The first-stage distillation body is also provided with a light-transmitting layer, a support layer and a photothermal material on one side.
[0014] In one possible design, the light-transmitting layer is fixedly installed on the side of the support layer away from the water inlet layer, the photothermal material is fixedly installed inside the support layer, the support layer is fixedly connected to one side of the adjacent water inlet layer, and the photothermal material is used to absorb sunlight and transfer heat downwards.
[0015] In one possible design, the water inlet layer is fixedly connected to one side of the adjacent drainage layer, and the other side of the drainage layer is in contact with and fixedly connected to the condensation surface of the condenser plate, so as to ensure that the drainage layer can collect condensed vapor droplets in a timely manner; the hydrophobic membrane is fixedly disposed on one side of the water inlet layer and is located between the water inlet layer and the drainage layer, so as to prevent water leakage from the water inlet layer and facilitate the passage of steam.
[0016] In one possible design, cylindrical connecting pipes are fixedly installed on both sides of the water inlet layer to connect to the brine layer; a cylindrical drain pipe is fixedly installed on one side of the drainage layer to discharge the collected condensate droplets.
[0017] In one possible design, the light-transmitting layer is made of a transparent material to ensure that its solar transmittance is not less than 98%.
[0018] In one possible design, the condensation surface of the condenser plate is hydrophobically treated to ensure rapid dripping of condensed vapor droplets.
[0019] In this application, each stage of the still is fixed by screw holes at the four corners of the support layer, water inlet layer, and drainage layer. Within the first-stage still body, a light-transmitting layer is installed above the support layer. This layer is made of hydrophobic modified transparent glass, which provides thermal insulation while preventing water vapor from condensing into a liquid film on the inner side of the glass. Sunlight passes through the upper transparent glass, is absorbed by the photothermal material in the middle layer, and is converted into heat energy that is transferred downwards. Then, brine is transported to the water inlet layer within the first-stage still body via a peristaltic pump and hose for evaporation. The water inlet layers of the second and third-stage still bodies are then connected via hoses, and the flowing brine exits from the outlet on the other side of the next-stage water inlet layer. Finally, the outlet pipe of the third-stage still body's water inlet layer is sealed, ensuring that each water inlet layer within the three-stage still body is filled with brine. When sunlight shines through the transparent glass... Upon reaching the surface of the photothermal material, the solar energy is absorbed and converted into heat, which is then transferred to the lower layers. As the first layer of steam passes through the hydrophobic membrane of the first-stage distillation body, it is condensed on the hydrophobic-coated condenser plate of the first-stage distillation body. The collected first-stage condensate then flows out through the outlet pipe of the drainage layer of the first-stage distillation body. Simultaneously, the condenser plate of the first-stage distillation body is directly connected to the inlet layer of the second-stage distillation body. The latent heat of condensation of the condenser plate of the first-stage distillation body is conducted to the inlet layer of the second-stage distillation body through the condenser plate itself, heating the brine therein for evaporation. The resulting water vapor can pass through the adjacent hydrophobic membrane and continue to condense into fresh water on the next stage condenser plate. After passing through the three-stage condensation structure, the remaining heat is slowly dissipated into the ambient air, and fresh water can then be collected in each drainage layer.
[0020] Beneficial effects: In this utility model, the solar interface seawater desalination multi-stage still achieves the step-by-step transfer and efficient utilization of heat through the multi-stage distillation design; the latent heat of condensation in each stage of the still can be directly conducted to the next stage of the inlet water layer through the condenser plate to heat the brine therefore for evaporation, thereby improving the heat utilization rate; the multi-stage distillation structure not only increases the condensation area of the steam, but also allows for the full collection of fresh water in the steam through the step-by-step condensation method, thereby increasing the fresh water production;
[0021] In this utility model, a solar-powered multi-stage seawater desalination still is described. The still has a compact structure, and the distillation bodies of each stage are fixedly connected by screw holes, which facilitates disassembly and assembly and is suitable for easy construction in different environments. Compared with traditional fixed solar stills, this still is lighter, more compact, easier to carry and move, and suitable for a variety of application scenarios.
[0022] In this invention, the solar interface seawater desalination multi-stage still has a light-transmitting layer made of transparent material with a solar transmittance of not less than 98%, ensuring that sunlight can fully irradiate the photothermal material and improving the photothermal conversion efficiency. Furthermore, the use of hydrophobic modified transparent glass as the light-transmitting layer effectively prevents water vapor from agglomerating into a liquid film on the inside of the glass, reducing heat loss and ensuring the stable operation of the still.
[0023] In this invention, the solar interface seawater desalination multi-stage distiller has a hydrophobic condenser plate, which ensures the rapid dripping of condensed vapor droplets and prevents the droplets from forming a liquid film on the condenser plate, thereby improving the condensation efficiency. At the same time, the drainage layer is in close contact with the condenser plate, ensuring that the condensed vapor droplets can be collected in time and discharged through the drainage pipe, thus preventing the retention of fresh water in the distiller.
[0024] In this invention, a solar-powered multi-stage seawater desalination still is described. It delivers brine to each stage of the inlet water layer via a peristaltic pump and hoses, simplifying the operation process and reducing the difficulty of operation. The multi-stage inlet water layers in the still are interconnected, enabling synchronous filling of brine and ensuring that each inlet water layer is filled with brine, thus guaranteeing the continuity and stability of the distillation process.
[0025] In this invention, the solar-powered multi-stage seawater desalination still achieves efficient heat utilization and increases freshwater production through its multi-stage design. Its compact structure makes it easy to disassemble and carry, suitable for various scenarios. A high-transmittance light-transmitting layer ensures ample sunlight exposure and reduces heat loss. The hydrophobic treatment of the condenser plate and the tight drainage layer design improve condensation efficiency and prevent freshwater retention. The interconnected multi-stage water inlet layers simplify brine filling operations and ensure continuous and stable distillation. The overall design is efficient and convenient, providing a practical solution for seawater desalination. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the overall disassembled structure of a solar-powered interface seawater desalination multi-stage distillation apparatus proposed in this utility model.
[0027] Figure 2 This is a schematic diagram of the temperature curves of the photothermal material surface and the condensation surface under intense sunlight irradiation for a multi-stage solar interface seawater desalination distillation apparatus proposed in this utility model.
[0028] Figure 3 This is a schematic diagram showing the mass change of water collected under a single intensity of sunlight in a multi-stage solar interface seawater desalination distillation apparatus proposed in this utility model.
[0029] Figure 4A schematic diagram of the water collection rate of a solar-powered multi-stage seawater desalination distillation apparatus under intense sunlight irradiation proposed in this utility model.
[0030] Figure 5 A schematic diagram showing the recording curves of ambient temperature and sunlight intensity in a natural environment for a solar-powered multi-stage seawater desalination distillation apparatus proposed in this utility model.
[0031] Figure 6 This is a schematic diagram of the temperature curves of the photothermal material surface and the condensation surface in a natural environment for a solar interface seawater desalination multi-stage distillation apparatus proposed in this utility model.
[0032] Figure 7 A schematic diagram of the water collection volume and water collection rate curves of a solar interface seawater desalination multi-stage distillation apparatus proposed in this utility model.
[0033] Figure 8 This is a schematic diagram of an existing detachable two-stage solar distillation apparatus proposed in this utility model.
[0034] Figure 9 This is a schematic diagram of an existing unidirectional heat transfer solar distiller proposed in this utility model.
[0035] Figure 10 This is a schematic diagram of an existing back-mounted self-storing multi-stage solar distiller proposed in this utility model.
[0036] In the diagram: 1. Transparent layer; 2. Support layer; 3. Photothermal material; 4. Water inlet layer; 5. Hydrophobic membrane; 6. Drainage layer; 7. Condensation plate; 8. Second-stage distillation body; 9. Third-stage distillation body; 10. Fixing layer. Detailed Implementation
[0037] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.
[0038] Example 1: Refer to Figure 1-10 A multi-stage distillation apparatus includes: a first-stage distillation body 8, a second-stage distillation body 8, a third-stage distillation body 9, and a fixed layer 10.
[0039] Each stage of the distillation body consists of a water inlet layer 4, a hydrophobic membrane 5, a drainage layer 6, and a condenser plate 7. Furthermore, a light-transmitting layer 1, a support layer 2, and a photothermal material 3 are additionally provided on one side of the first-stage distillation body.
[0040] In this embodiment, the light-transmitting layer 1 is fixedly installed on the side of the support layer 2 away from the water inlet layer 4. The light-transmitting layer 1 is made of a transparent material with a solar transmittance of not less than 98%, to ensure that as much sunlight as possible can penetrate the light-transmitting layer 1 and be absorbed by the photothermal material 3. The light-transmitting layer 1 is a hydrophobic modified transparent glass, which can ensure that water vapor does not condense into a liquid film on the inside of the glass while providing thermal insulation.
[0041] Furthermore, in this embodiment, the support layer 2, the photothermal material 3, and one side of the adjacent water inlet layer 4 are fixedly connected. The photothermal material 3 is fixedly installed inside the support layer 2 to absorb sunlight and transfer the absorbed heat downwards to the seawater in the water inlet layer 4, thereby triggering the evaporation of the seawater.
[0042] Furthermore, in this embodiment, the water inlet layer 4, the hydrophobic membrane 5, and the adjacent drainage layer 6 are fixedly connected on one side. The other side of the drainage layer 6 is in contact with and fixedly connected to the condensation surface of the condensation plate 7 to ensure that the drainage layer 6 can collect condensed vapor droplets in a timely manner. A hydrophobic membrane 5 is fixedly disposed between the water inlet layer 4 and the drainage layer 6. The hydrophobic membrane 5 can prevent seawater in the water inlet layer 4 from directly leaking into the drainage layer 6, while allowing steam to pass through smoothly, thereby achieving effective separation of steam and liquid.
[0043] In this embodiment, cylindrical connecting pipes are fixedly installed on both sides of the inlet water layer 4 to connect the brine layers of each stage of the distillation body. Each inlet water layer 4 inside the multi-stage still can be connected sequentially via flexible hoses. This design allows seawater to flow freely between the various distillation bodies, ensuring the continuity of the entire distillation process. Similarly, a cylindrical drain pipe is fixedly installed on one side of the drainage layer 6 to discharge the collected condensed vapor droplets for subsequent processing and collection.
[0044] In this embodiment, the condensing surface of the condensing plate 7 is hydrophobically treated. This design aims to ensure that condensed vapor droplets can quickly drip into the drainage layer 6, preventing droplets from accumulating on the condensing surface and thus improving condensation efficiency. The fixing layer 10 and the adjacent drainage layer 6 are fixed by screw holes at the four corners to ensure the condensing plate of the third-stage distillation body is fixed.
[0045] This application can be used in the field of seawater desalination technology, or in other fields applicable to this application.
[0046] Example 2: Reference Figure 1-7 An improvement based on Example 1: a solar-powered interface seawater desalination multi-stage distiller, which is applied to the field of seawater desalination technology;
[0047] As a further improvement to this embodiment, the light-transmitting layer 1 can be a highly transparent acrylic glass, transparent resin, etc.
[0048] As a further improvement to this embodiment, the support layer 2 can be made of polytetrafluoroethylene, polystyrene, or polycarbonate, and its surface is guaranteed to be white so as not to absorb excessive light.
[0049] As a further improvement to this embodiment, the photothermal material 3 can be a photothermal hydrogel, a photothermal sponge, a photothermal film, etc.
[0050] As a further improvement to this embodiment, the water inlet layer 4 can be an acrylic sheet or a polycarbonate sheet.
[0051] As a further improvement to this embodiment, the hydrophobic membrane 5 can be a PTFE hydrophobic membrane or a polyacrylic acid nonwoven fabric.
[0052] As a further improvement to this embodiment, the condenser plate 7 can be a metal plate with high thermal conductivity, such as an aluminum plate, a copper plate, or a stainless steel plate.
[0053] As a further improvement to this embodiment, the fixing layer 10 can be made of polytetrafluoroethylene, polystyrene, polycarbonate, etc.
[0054] To demonstrate the water collection performance of the three-stage still, this embodiment employs hydrogel photothermal materials for efficient evaporation. To better test the still's performance under stable conditions, thermocouples were used to monitor the temperature of the condenser plate 7 of each stage of the still, an electronic balance was used to record the collected water volume, ice packs were used as the condensation source, and the entire three-stage solar still was completely encased in insulating foam. Simultaneously, the device was used to conduct water collection experiments on a still with an 8*8 cm light-exposed area, using pure water, 3.5 wt% saline, and 10 wt% saline as the initial solutions under sunlight intensity. During the test, thermocouples were first used to record the temperature changes of the evaporation and condensation layers of the still within the first hour using pure water as the initial solution (e.g., ...). Figure 2 As shown), the temperature differences between the evaporation layer and the first, second, and third-stage condensation layers are approximately 5, 17, and 23°C, respectively. With prolonged illumination, the photothermal material 3 transfers heat downwards through the condenser plate 7, thereby heating each stage of the water inlet layer 4. The hydrophobic treatment of the condensation surface not only enhances the droplet condensation of water vapor but also fully utilizes the recovered latent heat for evaporation. We continuously tested the water collection volume of the distiller over three hours (e.g., ...). Figure 3 (As shown). The multi-stage still collected the most water from pure water as the initial solution; the reduced collection volume from brine may be due to the decreased water activity caused by the presence of salt. During three hours of continuous testing, the multi-stage still achieved a water collection rate of 0.82–1.14 kg / m³ in pure water. –2 h –1 The water collection rate in 3.5 wt% brine can reach 0.65-0.85 kg m³. –2 h –1The water collection rate in 10 wt% brine can reach 0.42-0.58 kg m³. –2 h –1 This demonstrates the practical possibility of the three-stage distillation apparatus (e.g.) Figure 4 (As shown).
[0055] Furthermore, we conducted an outdoor water collection experiment of the distiller inside an insulated box using 3.5 wt% brine as the initial solution and ice as the condensation source. We monitored hourly changes in solar radiation intensity, evaporator surface temperature, temperature of each condensation stage, and water collection volume (e.g., from 9:00 to 17:00). Figures 5-7 (As shown). During this process, the evaporator surface temperature gradually increased from 23.9 °C to ~49.8 °C at 13:00, and then dropped back to ~40 °C at 16:00. The temperature differences between the evaporation layer and the condensation layer were approximately 4, 10, and 15 °C, respectively. The temperature change curves for each stage coincided with the light intensity, and no salt deposition was observed on the hydrogel surface during a full day of evaporation. The total water collection volume of the distiller during the outdoor test was approximately 17.2 mL over 8 hours, and the highest water collection rate during the outdoor test reached 0.6 kg / m³. –2 h –1 The outdoor test performance was basically consistent with the laboratory performance, proving the feasibility of the three-stage still in actual operation.
[0056] The working principle and usage process of this technical solution are as follows: Each stage of the distiller is fixed by screw holes at the four corners of the support layer 2, water inlet layer 4, drainage layer 6, and fixing layer 10; in the first-stage distillation body, a light-transmitting layer 1 is set above the support layer 2. It is a transparent glass modified with a hydrophobic layer, which can ensure that water vapor does not condense into a liquid film on the inside of the glass while providing heat insulation; sunlight passes through the upper transparent glass, is absorbed by the photothermal material 3 in the middle layer, and is converted into heat energy and transferred downwards. Then, brine is transported to the water inlet layer 4 in the first-stage distillation body through a peristaltic pump and hose for evaporation. Afterwards, the water inlet layer 4 of the second-stage distillation body 8 and the water inlet layer 4 of the third-stage distillation body 9 are connected by hoses. The flowing brine will flow out from the outlet on the other side of the next-stage water inlet layer 4. Finally, the outlet pipe of the water inlet layer 4 of the third-stage distillation body 9 is sealed to ensure that each water inlet layer 4 in the three-stage distiller is filled with brine; when the sun Light shines through the transparent glass onto the surface of the photothermal material 3. After the photothermal material 3 absorbs the sunlight and converts it into heat energy, the heat is transferred to the lower layers. As the first layer of steam passes through the hydrophobic membrane 5 of the first-stage distillation body, it can be condensed on the hydrophobic-coated condenser plate 7 of the first-stage distillation body. The collected first-stage condensate can then flow out through the outlet pipe of the drainage layer 6 of the first-stage distillation body. At the same time, the condenser plate 7 of the first-stage distillation body is directly connected to the water inlet layer 4 of the second-stage distillation body. The latent heat of condensation of the condenser plate 7 of the first-stage distillation body is conducted to the water inlet layer 4 of the second-stage distillation body through the condenser plate 7 itself, and heats the brine therein to evaporate. The water vapor generated by evaporation can pass through the adjacent hydrophobic membrane 5 and continue to be condensed into fresh water on the next stage condenser plate 7. After passing through the three-stage condensation structure, the remaining heat is slowly dissipated into the ambient air, and then fresh water can be collected in each drainage layer 6.
[0057] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.
Claims
1. A solar interface seawater desalination multistage distiller, characterized in that, The utility model relates to a multi-stage distillation device, comprising: a first-stage distillation body, a second-stage distillation body (8), a third-stage distillation body (9), and a fixed layer (10); the first-stage distillation body, the second-stage distillation body (8), and the third-stage distillation body (9) each comprise a water inlet layer (4), a hydrophobic membrane (5), a water outlet layer (6), and a condensing plate (7); the first-stage distillation body is further provided with a light-transmitting layer (1), a supporting layer (2), and a photothermal material (3) on one side thereof; the fixed layer (10) is fixedly installed on the side of the third-stage distillation body (9) that is away from the first-stage distillation body.
2. A solar interface seawater desalination multistage distiller according to claim 1, wherein, the light-transmitting layer (1) is fixedly installed on the side of the supporting layer (2) that is away from the water inlet layer (4), the photothermal material (3) is fixedly installed in the supporting layer (2), the supporting layer (2) is fixedly connected to one side of the adjacent water inlet layer (4), and the photothermal material (3) is used for absorbing sunlight and transferring heat downward.
3. A solar interface seawater desalination multistage distiller according to claim 1, wherein, the water inlet layer (4) is fixedly connected to one side of the adjacent water outlet layer (6), the other side of the water outlet layer (6) is in contact with and fixedly connected to the condensing surface of the condensing plate (7), so as to ensure that the water outlet layer (6) can timely collect condensed steam droplets; the hydrophobic membrane (5) is fixedly arranged on one side of the water inlet layer (4) and is located between the water inlet layer (4) and the water outlet layer (6), so as to prevent the water inlet layer (4) from leaking and facilitate the passage of steam.
4. A solar interface seawater desalination multistage distiller according to claim 1, wherein, cylindrical communication pipes are fixedly arranged on both sides of the water inlet layer (4) and are used for communicating with a brine layer; a cylindrical water outlet pipe is fixedly arranged on one side of the water outlet layer (6) and is used for discharging the collected condensed steam droplets.
5. A solar interface seawater desalination multistage distiller according to claim 1, wherein, the light-transmitting layer (1) is made of transparent material and has a sunlight transmittance of not less than 98%.
6. A solar interface seawater desalination multistage distiller according to claim 1, wherein, the condensing surface of the condensing plate (7) is subjected to hydrophobic treatment, so as to ensure the rapid dripping of the condensed steam droplets.