CN-118724133-B - Salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing double-scale structure and preparation method thereof

Abstract

The invention provides a salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing a double-scale structure and a preparation method thereof, belonging to the field of salt-containing sewage treatment such as sea water desalination. The salt-resistant evaporator comprises an evaporation main body frame, a millimeter-sized channel and a hydrophilic photo-thermal conversion coating, wherein the evaporation main body frame is formed by connecting micron-sized single cells in an array mode, micron-sized holes are wrapped between every two of the micron-sized single cells, the millimeter-sized channel penetrates through the evaporation main body frame and is positioned in the geometric center of the evaporation main body frame, the millimeter-sized channel is communicated with the micron-sized holes wrapped between every two of the micron-sized single cells, and the hydrophilic photo-thermal conversion coating is arranged on the outer surface of the evaporation main body frame. The salt-resistant evaporator forms a temperature gradient and a concentration gradient inside, so that marangoni convection is triggered, salt is pumped from a high concentration area (micron-sized unit cell) to a low concentration area (millimeter-sized channel), and finally the salt is returned to a solution to be evaporated, and finally, the real-time salt migration is realized.

Inventors

• FU KUNKUN
• LI LUNCAO
• CUI XIAOYU
• ZHU HUIXIN

Assignees

• 同济大学

Dates

Publication Date

20260505

Application Date

20240702

Claims (4)

1. 1. A salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing a double-scale structure is characterized in that the salt-resistant evaporator is applied to provide stable evaporation flux of 3.417 kg/(m 2 .h) for 20wt% of brine for 120h continuously under 1 solar light intensity, Wherein the salt-resistant evaporator comprises an evaporation main body frame, a millimeter-sized channel and a hydrophilic photothermal conversion coating, The evaporation main body frame is a cylinder with the diameter of 4mm, the evaporation main body frame is formed by connecting micron-sized single cells with the diameter of 600 mu m in an array mode, micron-sized holes are wrapped between every two micron-sized single cells, The millimeter-sized channels penetrate through the evaporation main body frame and are positioned in the geometric center of the evaporation main body frame, the millimeter-sized channels are communicated with the micron-sized holes wrapped between every two micron-sized unit cells, the cross section of each millimeter-sized channel is circular, the hydraulic diameter of each millimeter-sized channel is 1mm, The hydrophilic photo-thermal conversion coating is arranged on the outer surface of the evaporation main body frame, the material of the hydrophilic photo-thermal conversion coating comprises hydrophilic multi-wall carbon nano tubes and acrylic resin, The salt resistant evaporator is characterized in that water supplementing along the length direction of the salt resistant evaporator is realized through a double-scale structure formed by the micron-sized single cells and the millimeter-sized channels, water supplementing from the millimeter-sized channels to the micron-sized single cells is realized, and marangoni convection is actively triggered, and salt ions are spontaneously sent back into the salt water from the inside of the salt resistant evaporator through the marangoni convection.
2. 2. The preparation method of the salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing the double-scale structure is characterized by comprising the following steps of: s10, establishing a three-dimensional structure model of the evaporation main body frame and the millimeter-level channel by using three-dimensional modeling software, and performing 3D printing; And S20, arranging the hydrophilic photothermal conversion coating on the surface of the evaporation main body frame to obtain the salt-resistant evaporator.
3. 3. The method for preparing the salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing the double-scale structure according to claim 2, wherein the method comprises the following steps of: Wherein, the step S10 and the step S20 also comprise the step S11 of removing the impurities on the surface of the printed evaporation main body frame by using a plasma cleaning machine, In step S20, after the hydrophilic photothermal conversion coating is disposed, a plasma cleaning machine is further used to clean the surface of the hydrophilic photothermal conversion coating.
4. 4. A method for preparing a salt evaporator for realizing salt migration and bidirectional water replenishing by utilizing a double-scale structure according to claim 2 or 3, wherein the method comprises the following steps: wherein in step S10, the 3D printing method comprises any one of resin-based 3D printing, ceramic-based 3D printing, metal 3D printing or 3D printing based on surface projection lithography, In step S20, the method of disposing the hydrophilic photothermal conversion coating is chemical deposition.

Description

Salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing double-scale structure and preparation method thereof Technical Field The invention belongs to the field of salt-containing sewage treatment such as sea water desalination and the like, and particularly relates to a salt-resistant evaporator for realizing salt migration and bidirectional water supplementing by utilizing a double-scale structure and a preparation method thereof. Background The salt-containing wastewater has an important proportion in the wastewater, has poor biochemistry and high treatment difficulty, and meanwhile, the increasingly strict environmental supervision policy promotes zero (near zero) emission to gradually become a necessary policy for high-salt wastewater management. In the zero (near zero) emission treatment process, the key is to carry out reduction treatment on the wastewater so as to improve the salt content of the wastewater and reduce the volume of the wastewater, thereby reducing the process energy consumption and the cost. However, the high-salt wastewater reduction treatment process consumes a great amount of energy to achieve salt/water separation, resulting in a much higher carbon emission than other industrial wastewater. Therefore, the construction of the green low-carbon wastewater concentration and decrement treatment technology has important significance for realizing the energy-saving and high-efficiency treatment of the high-salt wastewater and promoting the sustainable development of the economy of China. The solar energy interface evaporation technology utilizes solar energy to carry out local photo-thermal evaporation on the surface of an evaporator so as to realize efficient separation of salt/water, is recognized as a green low-carbon sustainable concentration separation technology, and has been widely studied and paid attention in recent years. However, most of the existing solar evaporators are manufactured by adopting a single-scale result or a single material, which causes salt scale precipitated on the surface and inside of the evaporator in the process of treating high brine to cause the blockage of the evaporator, and further causes the rapid reduction of the treatment performance of the system until the treatment capacity is lost, which is a main bottleneck problem restricting the development and application of the technology. Disclosure of Invention The present invention has been made to solve the above problems, and an object of the present invention is to provide a salt-resistant evaporator for realizing salt migration and water replenishment in both directions using a double-scale structure, and a method for manufacturing the same. The invention provides a salt-resistant evaporator for realizing salt migration and bidirectional water supplementing by utilizing a double-scale structure, which is characterized by comprising an evaporation main body frame, a millimeter-sized channel and a hydrophilic photothermal conversion coating, wherein the evaporation main body frame is formed by connecting micron-sized single cells in an array mode, micron-sized holes are wrapped between every two of the micron-sized single cells, the millimeter-sized channel penetrates through the evaporation main body frame and is positioned in the geometric center of the evaporation main body frame, and the millimeter-sized channel is communicated with the micron-sized holes wrapped between every two of the micron-sized single cells. The salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing the double-scale structure can also be characterized in that the structure of the evaporation main body frame comprises any one of a cylinder, a prism, a pyramid or a round table. The salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing the double-scale structure provided by the invention can also be characterized in that when the structure of the evaporation main body frame is a cylinder, the diameter of the evaporation main body frame is 4-20 mm. The salt-resistant evaporator for realizing salt migration and bidirectional water replenishing by utilizing the double-scale structure provided by the invention can be further characterized in that the shape of the micron-sized unit cell is any one of the shapes shown in fig. 4, and the size of the micron-sized unit cell is 50-900 mu m. The salt-resistant evaporator for realizing salt migration and bidirectional water supplementing by utilizing the double-scale structure provided by the invention can be further characterized in that the cross section of the millimeter-sized channel comprises any one of a circle, a rectangle or a triangle, and the hydraulic diameter of the millimeter-sized channel is 1-3 mm. The salt-resistant evaporator for realizing salt migration and bidirectional water supplementing by utilizing the double-scale str