Preparation method of a gel evaporator with a straight channel anti-fouling type photo-thermal interface and application thereof

Abstract

The present application belongs to the technical field of wastewater treatment, and provides a preparation method of a gel evaporator with a straight-channel anti-fouling type photo-thermal interface and application thereof. The preparation method is mixing a chitosan solution, a chitosan grafting solution and a glutaraldehyde solution; placing the mixed solution in a container for crosslinking, directional freezing through liquid nitrogen, freezing drying of the frozen material, obtaining an anti-fouling type gel with a straight channel, and finally adsorbing and fixing a layer of photo-thermal layer on the surface of the gel to obtain the gel evaporator with a straight-channel anti-fouling type photo-thermal interface. The internal pores of the evaporator prepared by the present application are arranged in a direction, realizing high-speed continuous water evaporation. The introduction of a polyamphoteric substance 3-(dimethyl(4-vinylbenzyl)amino)propane sulfonate effectively avoids salt crystallization, and guarantees stable and efficient evaporation. The evaporator has a certain ion repulsion and rapid water replenishment, realizes high evaporation rate, and the surface is free of salt crystallization.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and particularly relates to a preparation method of a gel evaporator with a straight-channel anti-fouling type photo-thermal interface and application thereof. BACKGROUND

[0002] In the field of resource protection and sustainable development, salt resources contained in high-salinity brine and wastewater have become a hot resource that has attracted much attention. These high-salinity water is rich in magnesium, potassium and other elements that are essential for agriculture, information technology and environmental protection. Solar-driven interfacial evaporation technology provides an efficient solution for desalination and concentration of high-salinity water. With the significant advantages of low cost and high processing efficiency, it has become a core processing technology that has attracted much attention in this field.

[0003] To further improve the processing efficiency of the interfacial evaporation technology, the preparation and selection of the photo-thermal interfacial evaporator are crucial. In recent years, a variety of interfacial evaporators with excellent performance have been successfully developed, and their core performances such as low heat loss, wide-spectrum light absorption and low evaporation enthalpy have achieved major breakthroughs. However, the popularization of this technology still faces many challenges. First, the evaporation rate of the evaporator is slow, which cannot meet the needs of industrial rapid processing. Second, salt deposition seriously affects the performance and service life of the evaporator. In addition, the existing photo-thermal materials lack stability in strong acid and strong base environments.

[0004] Therefore, it is of great significance to develop a high-efficiency evaporation technology that can accelerate evaporation, prevent salt deposition and optimize the structural design to meet the needs of industrial development and sustainable development. SUMMARY

[0005] The purpose of the present application is to provide a preparation method of a gel evaporator with a straight-channel anti-fouling type photo-thermal interface and application thereof, aiming to solve the problems of slow evaporation and easy fouling of existing evaporators.

[0006] Specifically, the preparation method of the gel evaporator with a straight-channel anti-fouling type photo-thermal interface is to mix a chitosan solution, a chitosan grafting solution and a glutaraldehyde solution; place the mixed solution in a container for crosslinking, directionally freeze the material by liquid nitrogen, and then freeze-dry the frozen material to obtain an anti-fouling gel with a straight channel. Finally, a layer of photo-thermal layer is adsorbed and fixed on the surface of the gel to obtain the gel evaporator with a straight-channel anti-fouling type photo-thermal interface.

[0007] Further, the preparation steps of the chitosan grafting solution are as follows:

[0008] Step 1, dissolve N,N-dimethyl-4-vinylbenzylamine and 1,3-propane sulfone in acetonitrile, and heat and stir the mixed solution to obtain a precursor of (3-(dimethyl(4-vinylbenzyl)amino)propane sulfonate) DVBAPS;

[0009] Step 2, collect the filter residue of the DVBAPS precursor in step 1, wash and remove unreacted raw materials and other by-products to ensure the purity of the DVBAPS powder, and obtain the DVBAPS powder after drying;

[0010] Step 3, dissolve the DVBAPS powder in step 2 in water, and inertify the homogeneous solution by nitrogen blowing to obtain an inertified homogeneous solution;

[0011] Step 4, add chitosan solution and glutaraldehyde solution to the inertified homogeneous solution obtained in step 3, and transfer the mixed solution to a three-necked flask equipped with a condensation reflux device, continuously stir and heat in an environment of 80°C to obtain a chitosan grafted solution.

[0012] Further, in step 1, the N,N-dimethyl-4-vinylbenzylamine accounts for 1.0-5.0% of the volume of the acetonitrile solution, and the 1,3-propane sulfone accounts for 1.0-5.0% of the volume of the acetonitrile solution. The molar ratio of N,N-dimethyl-4-vinylbenzylamine to 1,3-propane sulfone is 1:0.9-1:1.1; the heating temperature is 45-55°C, the stirring speed is 400-500 rpm, and the stirring time is 36-48 h.

[0013] Further, in step 2, the total amount of ethanol used for washing is 30-60 ml, and the washing is performed 3-5 times. After washing, the sample is dried in a vacuum environment at 30-40°C for 24-48 h. The ethanol used is HPLC grade ethanol; in step 3, the DVBAPS powder is dissolved in water to prepare a DVBAPS solution with a concentration of 5-15 wt%; the nitrogen blowing time is 10-30 min.

[0014] Further, the nitrogen blowing is performed in a two-stage operation of "first fast blowing for 5 min (flow rate 100 mL / min) and then slow maintenance for 10-20 min (flow rate 50 mL / min)", which ensures that the air can be effectively and quickly removed.

[0015] Further, in step 4, the concentration of the chitosan solution is 0.5-1.5 wt%, and the total amount of chitosan added is 1:1.25-1:5 of the mass ratio of chitosan to DVBAPS. The glutaraldehyde solution is a 25% aqueous solution, and the amount added is 4-12% of the total amount of chitosan.

[0016] Further, in step 4, the reaction is continuously stirred at 80°C for 4-8 h, and the stirring speed is 300-500 rpm, so that the content of by-products in the grafted product is ≤3%.

[0017] Further, the chitosan grafting solution is mixed with the ungrafted chitosan solution for 10-15 min, and then the glutaraldehyde solution is added to avoid uneven gel crosslinking caused by local glutaraldehyde excess, which reduces the compression strength of the final gel and causes uneven porosity distribution. The concentration of the chitosan solution is 0.5-1.5 wt%, the glutaraldehyde solution is a 20-25% aqueous solution, and the volume ratio of the chitosan grafting solution, the chitosan solution, and the glutaraldehyde solution is 1:4:2-1:2:1.

[0018] Further, the chitosan solution is obtained by dissolving chitosan powder in acetic acid, the volume fraction of acetic acid is 1%, and the mass ratio of acetic acid to chitosan powder is 1:0.5-1:2. This ratio allows the chitosan to completely dissolve in the weak acid solution within 1-3 h, and the viscosity of the solution after dissolution is moderate, avoiding uneven mixing during subsequent grafting due to high viscosity.

[0019] Further, the chitosan powder is dissolved in acetic acid, and a transparent and uniform solution is obtained by stirring at room temperature for 4-6 h. After standing for 6-12 h to eliminate the bubbles in the solution, the chitosan solution is obtained. After mixing the chitosan grafting solution, the chitosan solution, and the glutaraldehyde solution, stirring is performed at a speed of 250-450 rpm for 3-5 min; standing for crosslinking for 20-60 min; submerging the bottom of the container in liquid nitrogen for 30-70 min; and freeze-drying at a temperature of -45 to -60°C for 12-36 h. This can stabilize the straight channels of the gel and avoid channel collapse caused by insufficient ice crystal formation. Further, the container is a cylindrical container with a copper sheet at the bottom and a polytetrafluoroethylene wall.

[0020] Further, the specific steps for adsorbing and fixing a layer of photothermal layer on the surface of the gel are as follows: the anti-fouling gel with straight channels is immersed in a pyrrole solution and an ammonium persulfate solution for 10-30 min each time, until the formed polypyrrole completely covers the gel and the excess substances on the surface are washed away, and then an anti-fouling photothermal interface gel evaporator with straight channels is obtained.

[0021] Further, the pyrrole solution is prepared by mixing pyrrole and ethanol at a volume ratio of 1:80-1:40, and the solution usage is 10-20 ml; the ammonium persulfate solution is prepared by mixing ammonium persulfate and water at a mass ratio of 3:125-6:125, and the solution usage is 10-20 ml.

[0022] Further, deionized water is used for cleaning, and the single usage is 10-20 ml, with a total of 3-5 times; the cleaning method is to place the gel in deionized water and use an ultrasonic cleaning machine for ultrasonic treatment for 20-30 min.

[0023] Further, the ultrasonic cleaning frequency is 40-60 kHz, the ultrasonic power 100-200 W, and the flushing frequency and flushing time of 5-10 min / time, so that more than 98% of the residual pyrrole and ammonium persulfate on the surface of the gel can be removed without damaging the bonding force between the photothermal layer and the gel base material.

[0024] The application also provides a use of the straight-channel anti-fouling photothermal interface gel evaporator as described above, and the straight-channel anti-fouling photothermal interface gel evaporator is used for concentrating high-salinity brine.

[0025] Further, the asymmetric structure formed by the floating support enables the evaporator to rotate around an arbitrary axis and realize self-cleaning.

[0026] Further, the floating support adopts an elliptical structure design, and the long axis and the short axis direction are asymmetrically arranged with fixed positions, and the rotation triggering mechanism is realized by the offset of the center of gravity to maintain the upright self-floating state of the evaporator.

[0027] Further, the fixed positions of the evaporator are asymmetrically distributed along the long axis and the short axis of the floating support, and when the side overturning occurs, the dynamic center of gravity is unbalanced to automatically trigger the rotating cleaning action.

[0028] Further, the rotating axis of the evaporator can be selected as the long axis or the short axis direction, and the external force input mode includes but is not limited to human power, mechanical force, wind power or water power to realize flexible overturning.

[0029] The existence of the straight channel of the evaporator can ensure that the water transmission direction is not limited, and the evaporator after rotation still has a high evaporation rate. In addition, the rotating state based on the structure design of the auxiliary device can accelerate the elimination of dirt, and the cleaning effect is enhanced through the stress change of the interface and the action of water flow during the overturning process to ensure that the evaporation continues and is not affected.

[0030] Further, the auxiliary device is made of a thin pearl cotton foam board. The thin pearl cotton foam board is cut into an elliptical shape, and one straight-channel anti-fouling photothermal interface gel evaporator is symmetrically installed at the geometric center of the elliptical auxiliary device, and the exposed lengths of the two evaporators are set to different sizes. When the water gel is pushed by external force, the system rotates around the short axis, the center of gravity is offset with the gel position to cause imbalance, realizes the unstable horizontal placement and smooth overturning, and when rotating around the long axis, the long axis direction foam pushes away the water body to generate upward buoyancy on the underwater gel, also breaks the horizontal balance to ensure smooth overturning.

[0031] Compared with the prior art, the application has the following remarkable beneficial effects:

[0032] 1. The prepared evaporator has directional pores (straight channels), which are derived from the directional temperature gradient formed in the container during freezing crosslinking, so that the water in the gel precursor solution grows into vertical ice crystals, and after freeze-drying, directional pores are formed. The size of the channel can provide strong capillary force and weak resistance, ensuring the rapid supply of bulk water, significantly improving the water flow speed and evaporation speed inside the evaporator, and realizing high-speed continuous water evaporation.

[0033] 2. The polyamphoteric substance 3-(dimethyl(4-vinylbenzyl)amino) propanesulfonate is introduced in the present application, which has cationic and anionic groups in the molecule and can produce Debye effect. Dynamic ion balance is formed with salt ions in the solution, which not only weakens the driving force of salt ion migration, but also blocks the enrichment of salt ions to the evaporation surface through charge effect, effectively avoiding salt deposition and ensuring stable and efficient evaporation.

[0034] 3. The prepared evaporator has certain ion repulsion and rapid water replenishment. The ion repulsion is derived from the fixed charge group of the polyamphoteric substance, which can block salt ions from approaching the evaporation surface through electrostatic repulsion. Combined with the rapid water replenishment of directional pores, it can dilute the high concentration of salt water on the surface through convection diffusion to avoid salt deposition. In a 20wt% NaCl solution, continuous evaporation for 8h still maintains a high evaporation rate, and no salt crystallization occurs on the surface.

[0035] 4. The prepared evaporator can realize stable self-floating through an auxiliary device, and can be turned over by external force to effectively eliminate the dirt generated on the evaporation surface after long-term use. The external force can be human power, mechanical force, wind power or water power. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The mass changes of pure water produced by evaporation at different times for the evaporators prepared in Example 1, Example 2 and Example 3.

[0037] Figure 2 The evaporation rate and evaporation efficiency of the evaporators prepared in Example 1, Example 2 and Example 3 are compared.

[0038] Figure 3 The evaporation rates of the evaporators prepared in Example 1, Example 2 and Example 3 in different concentrations of salt water.

[0039] Figure 4 The evaporation rate changes of the evaporators prepared in Example 1, Example 2 and Example 3 in 20wt% sodium chloride aqueous solution.

[0040] Figure 5 The scanning electron microscope image of the internal structure of the evaporator prepared in Example 2.

[0041] Figure 6A schematic diagram of the use of the evaporator prepared in Example 1, Example 2, Example 3. a is a short axis rotation; b is a long axis rotation. DETAILED DESCRIPTION

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0043] The technical solutions of the present application will be further described below in combination with the embodiments.

[0044] Example 1

[0045] The present embodiment provides a preparation method of a gel evaporator with a straight channel anti-fouling type light-heat interface, and the specific steps are as follows:

[0046] Step one: preparation of chitosan grafting solution

[0047] 1.1, 3.22g of N,N-dimethyl-4-vinylbenzylamine and 2.44g of 1,3-propane sulfone were dissolved in 100ml of acetonitrile, and the solution was stirred at 500rpm under the environment of 50℃ for 48h to obtain the precursor of DVBAPS;

[0048] 1.2, the DVBAPS precursor solution was filtered to collect the precipitate, and the precipitate was washed with a total amount of 60ml of ethanol for 5 times, and then dried at 40℃ in a vacuum environment for 30h to obtain the amphoteric ion DVBAPS powder;

[0049] 1.3, 5g of DVBAPS powder was dissolved in 100ml of water, and the solution was inertized for 20min by nitrogen blowing, and the nitrogen blowing was carried out in two stages, i.e. fast blowing for 5min (flow rate 100ml / min) and slow blowing for 15min (flow rate 50ml / min), to obtain a uniform inertized solution;

[0050] 1.4, 4ml of chitosan solution with a concentration of 1.5wt% and 2ml of glutaraldehyde aqueous solution with a concentration of 25% were added to the inertized uniform solution, and the mixed solution was transferred to a three-necked flask equipped with a condensation reflux device, and heated at 80℃ under the stirring speed of 500rpm for 8h to obtain the chitosan grafting solution.

[0051] Step two: preparation of anti-fouling gel with straight channel

[0052] 2.1, 0.5 g chitosan powder was dissolved in 99.5 g 1wt% acetic acid solution, stirred at room temperature for 4 h to obtain a transparent and uniform solution, and then placed for 10 h to obtain a chitosan solution;

[0053] 2.2 The chitosan grafting solution prepared in step 1 was mixed with the ungrafted chitosan solution prepared in 2.1 at 300 rpm for 10 min, and then 2 mL of 25% glutaraldehyde aqueous solution was added, and stirred at 400 rpm for 3 min;

[0054] 2.3, the mixed solution prepared in 2.2 was placed in a cylindrical container with a copper sheet at the bottom and a polytetrafluoroethylene wall, and was placed for crosslinking for 30 min;

[0055] 2.4, the crosslinked mixed solution was transferred to a liquid nitrogen environment at -196 ℃ and frozen for 1 h to obtain a frozen gel; the frozen gel was transferred to a freeze dryer and dried at -50 ℃ for 24 h to obtain an anti-fouling gel with straight channels.

[0056] Step three: preparation of anti-fouling gel evaporator with straight channel

[0057] 3.1, 240 μL of pyrrole was dissolved in 10 mL of ethanol solution to prepare a pyrrole solution, and 0.24 g of ammonium persulfate particles was dissolved in 10 mL of deionized water to prepare an ammonium persulfate solution;

[0058] 3.2, the anti-fouling gel with straight channels obtained in step two was immersed in the pyrrole solution and the ammonium persulfate solution respectively for 30 min;

[0059] 3.3, the soaked gel was washed with 20 ml of deionized water for 4 times to obtain an anti-fouling gel evaporator with straight channels. The washing method is to place the gel in deionized water and use an ultrasonic cleaning machine for ultrasonic treatment for 30 min. The frequency of ultrasonic cleaning is 50 kHz, and the ultrasonic power 1200 W is matched with the flushing frequency and the flushing time of 6 min / time.

[0060] Example 2

[0061] This example refers to example 1, the difference between this example and example 1 is that in this example, 1.0 g of chitosan powder is dissolved in 99.0 g of 1wt% acetic acid solution.

[0062] Example 3

[0063] This example refers to example 1, the difference between this example and example 1 is that in this example, 1.5 g of chitosan powder is dissolved in 98.5 g of 1wt% acetic acid solution.

[0064] Performance test:

[0065] 1 Water evaporation test comparison

[0066] The water evaporation test was carried out by placing the gel evaporator prepared in Example 1, Example 2 and Example 3 into a crystallizing dish containing 50 ml of water, and irradiating it with a xenon lamp equipped with an AM 1.5 filter to simulate sunlight. At the same time, an irradiance meter was used to calibrate the sunlight intensity to maintain a sunlight intensity of one sun (1000 W / m 2 ). The mass loss of water was recorded in real time by an electronic balance to measure the interfacial evaporation capacity of the sample. The same volume of water was placed in the balance and placed in a dark field environment to record the natural evaporation amount after 2 hours as a control group. The results of the change of the mass of water at the bottom of different evaporators with the irradiation time under one sun irradiation are shown in Figure 1 . Figure 2 The water evaporation results of different evaporators were compared. The black triangles in the figure represent the evaporation rate, and the red triangles represent the evaporation efficiency. Among them, the product of Example 2 can simultaneously maintain a high evaporation rate (5.87 kg·m -2 ·h -1 ) and evaporation efficiency (90.7%). It is proved that the evaporator of Example 2 has excellent water evaporation effect.

[0067] 2 Salt resistance experiment

[0068] In order to study the influence of different salt concentrations of aqueous solution on the evaporation performance of the evaporator of the present application, deionized water and sodium chloride were used to prepare sodium chloride aqueous solution with mass fraction of 3.5wt%, 10wt%, 15wt%, 20wt% for salt water evaporation test Figure 3 ), and 20wt% of sodium chloride aqueous solution was used for salt resistance test for long time evaporation Figure 4 ).

[0069] As can be seen from Figure 3 and Figure 4 , the product prepared in Example 3 can maintain a high evaporation rate in different concentrations of sodium chloride aqueous solution, and the evaporation rate changes little in the continuous 8h evaporation process, which reflects the excellent salt resistance of the evaporator prepared in Example 3.

[0070] 3 Analysis of the internal structure of the evaporator

[0071] The electron microscope image of the gel evaporator with straight channel anti-fouling type photothermal interface prepared in Example 2 is shown in Figure 5 . As can be seen from Figure 5 , the presence of copper sheet in the container changes the temperature gradient, making the reticular structure into a vertical channel.

[0072] Example 4

[0073] The present embodiment provides the application of the straight-channel anti-fouling photothermal interface gel evaporator prepared according to any one of embodiments 1-3 to concentrate high-salinity brine, such as Figure 6 As shown, the asymmetric structure is formed by the floating support, so that the evaporator rotates around any axis and realizes self-cleaning. The floating support is made of thin pearl cotton foam board. It is cut into an oval shape, and one straight-channel anti-fouling photothermal interface gel evaporator is symmetrically installed at the geometric center of the oval floating support, and the exposed lengths of the two evaporators are set to different sizes. When the water gel is pushed by an external force (the external force input methods include but are not limited to human power, mechanical force, wind power or water power), the system rotates around the short axis, the center of gravity deviates with the gel position, causing imbalance, realizing unstable horizontal placement and smooth overturning; when rotating around the long axis, the foam in the long axis direction pushes away the water, generating upward buoyancy on the underwater gel, also breaking the horizontal balance, ensuring smooth overturning.

[0074] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application.

Claims

1. A method for preparing a straight-channel, anti-fouling photothermal interface gel evaporator, characterized in that, The method involves mixing a chitosan solution, a chitosan grafting solution, and a glutaraldehyde solution; placing the mixed solution in a container for static cross-linking; directional freezing using liquid nitrogen; freeze-drying the frozen material to obtain an antifouling gel with a straight channel; and finally adsorbing and fixing a photothermal layer on the gel surface to obtain an antifouling photothermal interface gel evaporator with a straight channel. The preparation steps of the chitosan grafting solution are as follows: Step 1: Dissolve N,N-dimethyl-4-vinylbenzylamine and 1,3-propanesulfonone in acetonitrile, and heat and stir the mixture to obtain the DVBAPS precursor; Step 2: Filter the DVBAPS precursor from Step 1, collect the filter residue, wash and dry it to obtain DVBAPS powder. Step 3: Dissolve the DVBAPS powder from Step 2 in water and blow it with nitrogen to obtain an inertized homogeneous solution; Step 4: Add chitosan solution and glutaraldehyde solution to the inertized homogeneous solution obtained in step 3, transfer the mixed solution to a flask and heat to obtain chitosan graft solution.

2. The method according to claim 1, characterized in that, In step 1, N,N-dimethyl-4-vinylbenzylamine accounts for 1.0~5.0% of the volume of the acetonitrile solution, 1,3-propanesulfonone accounts for 1.0~5.0% of the volume of the acetonitrile solution, and the molar ratio of N,N-dimethyl-4-vinylbenzylamine to 1,3-propanesulfonone is 1:0.9~1:1.1; the heating temperature is 45~55℃, the stirring speed is 400~500rpm, and the stirring time is 36~48h.

3. The method according to claim 1, characterized in that, In step 2, the product is cleaned with ethanol, with a total ethanol volume of 30-60 ml and 3-5 cleaning cycles. After cleaning, it is dried in a vacuum environment at 30-40°C for 24-48 hours. In step 3, DVBAPS powder is dissolved in water to prepare a DVBAPS solution with a concentration of 5-15 wt%. The nitrogen blowing time is 10-30 min.

4. The method according to claim 1, characterized in that, In step 4, the chitosan solution concentration is 0.5~1.5wt%, and the total amount of chitosan added is in a mass ratio of 1:1.25~1:5 to DVBAPS; the glutaraldehyde solution is a 25% aqueous solution, and the amount added is 4~12% of the total amount of chitosan.

5. The method according to claim 1, characterized in that, First, stir and mix the chitosan grafting solution with the ungrafted chitosan solution for 10-15 minutes, then add glutaraldehyde solution. The chitosan solution concentration is 0.5-1.5 wt%, and the glutaraldehyde solution is a 20-25% aqueous solution. The volume ratio of chitosan grafting solution, chitosan solution and glutaraldehyde solution is 1:4:2 to 1:2:

1.

6. The method according to claim 5, characterized in that, The chitosan solution is obtained by dissolving chitosan powder in acetic acid, wherein the volume fraction of acetic acid is 1% and the mass ratio of acetic acid to chitosan powder is 1:0.5~1:

2. Chitosan grafting solution, chitosan solution and glutaraldehyde solution are mixed and stirred at 250-450 rpm for 3-5 min; allowed to stand for crosslinking for 20-60 min; the bottom of the container is submerged in liquid nitrogen and frozen for 30-70 min; the freeze-drying temperature is -45 to -60℃ and the freeze-drying time is 12-36 h.

7. The method according to claim 6, characterized in that, The specific steps for adsorbing and fixing a photothermal layer on the gel surface are as follows: The antifouling gel with straight channels is immersed in pyrrole solution and ammonium persulfate solution for 10-30 minutes each. After cleaning, a photothermal interface gel evaporator with straight channels is obtained.

8. The application of the straight-channel anti-fouling photothermal interface gel evaporator obtained by the preparation method according to any one of claims 1-7, characterized in that, The aforementioned straight-channel anti-fouling photothermal interface gel evaporator is used for concentrating high-salinity brine.

9. The application according to claim 8, characterized in that, An asymmetric structure is formed by floating supports, allowing the evaporator to rotate around any axis and achieve self-cleaning.

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