A device for utilizing residual pressure of concentrated brine from seawater desalination and reverse osmosis

Abstract

The present application relates to the field of seawater desalination, and in particular to a device for utilizing the residual pressure of reverse osmosis concentrated brine for seawater desalination, comprising: a reaction mechanism comprising a fixed portion and a rotating portion, the fixed portion being provided with a concentrated brine inlet, a residual pressure inlet, a carbon dioxide waste gas inlet and outlet, the residual pressure inlet and outlet being located at both ends of the rotating portion, and a reaction chamber being provided in the rotating portion; a screening mechanism for receiving reacted solid particles and water, and screening solid particles with a size within a set range; a cleaning mechanism for frictionally flushing the ultrafiltration membrane with solid particles and water between the screening mechanism and the ultrafiltration membrane; and a cleaning mechanism comprising a first liquid inlet pipe between the screening mechanism and the water inlet pipe. The present application uses the residual pressure of the secondary reverse osmosis brine to drive the primary reverse osmosis concentrated brine to react with carbon dioxide to generate solid calcium carbonate particles, and uses the solid particles and the clean brine produced by the secondary reverse osmosis to clean the ceramic ultrafiltration membrane. While achieving energy utilization and carbon emission reduction, it can also enhance the cleaning effect of the ceramic ultrafiltration membrane.

Description

Technical Field

[0001] The present application relates to the field of seawater desalination, and in particular to a device for utilizing excess pressure of concentrated brine in seawater desalination reverse osmosis. Background Art

[0002] With the increasing global shortage of freshwater resources, seawater desalination technology has been widely used and researched as an effective means of increasing water resources. Currently, the common method for treating seawater is to first remove suspended matter, colloids, bacteria, viruses, macromolecular organic matter, some emulsified oils, and greases through ultrafiltration; then, reverse osmosis is used to remove dissolved salts, small molecular organic matter, heavy metal ions, and microbial residues. However, due to the small pore size of the reverse osmosis membrane, high pressure must be applied to the water to ensure smooth passage through the membrane for filtration, while the original seawater is concentrated. Therefore, the reverse osmosis process produces highly concentrated brine with residual pressure energy. For example, primary reverse osmosis produces high-salinity brine rich in calcium and magnesium ions. However, because it passes through the energy conversion device, the discharged brine has a low residual pressure. Secondary reverse osmosis produces clean, fresh brine with a high residual pressure. Its salt content is much lower than that of the original seawater, but because it does not undergo energy conversion, the fresh brine discharged from the secondary reverse osmosis still contains a high residual pressure energy. If the fresh brine produced by primary reverse osmosis is discharged directly into the sea, due to its high salinity, it will pose a serious risk to the marine ecological environment. At the same time, if the fresh brine produced by secondary reverse osmosis with a high residual pressure is discharged directly, it will also lead to a waste of energy and water resources.

[0003] Carbon dioxide (CO2) is one of the main greenhouse gases contributing to global warming, and its emission control is a key area of global environmental protection. CO2 emissions primarily originate from industrial production processes. Currently, to reduce water supply costs, desalination plants are typically located near industrial areas. This makes the large amounts of CO2 tail gas emitted during industrial production a valuable resource. Therefore, combining the CO2 from industrial tail gas with the high-salinity brine produced by the desalination process to achieve efficient recycling of this resource is a key area of technological innovation.

[0004] In addition, ultrafiltration membranes are susceptible to contamination during long-term operation, especially when the inlet water quality is poor, such as during jellyfish outbreaks. The fouling of the membrane by colloidal substances will seriously affect the system's operating efficiency and the life of the membrane elements, especially the internal pressure membrane. Summary of the Invention

[0005] In response to the above problems, the present application provides a device for utilizing the residual pressure of concentrated brine from seawater desalination reverse osmosis, which utilizes the high-pressure environment provided by the residual pressure of clean brine generated by secondary reverse osmosis to achieve efficient conversion of primary reverse osmosis concentrated brine with carbon dioxide in industrial exhaust gas to produce calcium carbonate solid particles, and utilizes the generated solid particles and the clean brine generated by secondary reverse osmosis to clean the ceramic ultrafiltration membrane. On the basis of realizing energy utilization, it also solves the problem of ultrafiltration membrane fouling and clogging, especially under harsh water inlet conditions such as severe colloidal pollution during jellyfish outbreaks, thereby improving the overall efficiency and stability of the system.

[0006] The present application provides a device for utilizing residual pressure of concentrated brine by reverse osmosis desalination of seawater, which adopts the following technical solution:

[0007] A device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis, comprising:

[0008] The reaction mechanism comprises a fixed portion and a rotating portion, wherein the fixed portion is provided with a concentrated brine inlet for connecting to the first-stage reverse osmosis, a residual pressure inlet for connecting to the second-stage reverse osmosis, a carbon dioxide waste gas inlet for supplying carbon dioxide gas, and an outlet. The residual pressure inlet and the outlet are respectively located at the two ends of the rotating portion. A reaction chamber is provided inside the rotating portion, which can be connected to the residual pressure inlet, the concentrated brine inlet, and the carbon dioxide waste gas inlet respectively through the rotation of the rotating portion.

[0009] Screening mechanism: connected to the outlet, used to receive the solid particles and water discharged from the outlet after the reaction of concentrated brine and carbon dioxide, and output the solid particles with a size within a set range after screening;

[0010] Cleaning mechanism: includes a placement bin connected to the screening mechanism for holding solid particles with a size within a set range and a first liquid inlet pipe connected to the secondary reverse osmosis, the other end of the first liquid inlet pipe is connected to the ultrafiltration membrane, the placement bin is connected to the side wall of the first liquid inlet pipe, so that the solid particles in the placement bin are driven to the ultrafiltration membrane by the residual pressure of the secondary reverse osmosis to frictionally flush the ultrafiltration membrane; one end of the ultrafiltration membrane is a water inlet pipe, and the other end is a water production pipe and a concentrated water discharge pipe; the first liquid inlet pipe is connected to the water inlet pipe.

[0011] By adopting this technical solution, the residual pressure generated by the secondary reverse osmosis process can be effectively utilized to drive a chemical reaction between the concentrated brine from the primary reverse osmosis process and carbon dioxide from industrial exhaust gases to produce solid calcium carbonate particles. These particles, mixed with the clean, low-pressure brine discharged from the secondary reverse osmosis process, can then be used to clean the ultrafiltration membranes. This not only effectively recycles and utilizes energy, but also significantly improves the operating efficiency and service life of the ultrafiltration membranes under harsh influent conditions. This is particularly suitable for resolving the severe membrane blockage caused by colloidal contamination during jellyfish outbreaks, thereby improving the stability and economic efficiency of the entire desalination system.

[0012] Optionally, the outlet is connected to a first air inlet pipe, and the cleaning mechanism further includes a first air inlet pipe connected between the first air inlet pipe and the water inlet pipe.

[0013] By adopting the above technical solution, the function of introducing the gases generated during the reaction process into the cleaning mechanism is achieved. This allows these gases to be further guided to the water inlet pipe and participate in the ultrafiltration membrane cleaning process, thereby enhancing the cleaning effect and improving resource utilization.

[0014] Optionally, a second air inlet pipe is arranged between the first air inlet pipe and the water production pipe, and control valves are installed on both the first air inlet pipe and the second air inlet pipe; a second liquid inlet pipe is arranged between the first liquid inlet pipe and the water production pipe, and control valves are installed on both the first liquid inlet pipe and the second liquid inlet pipe.

[0015] By adopting the above technical solution, precise control of the gas-liquid flow path in the device is achieved. Specifically, installing a control valve on the first air inlet pipe can effectively regulate the opening and closing state of the first air inlet pipe, avoiding unnecessary gas loss; setting a second air inlet pipe and the control valve thereon further optimizes the gas flow management, ensuring that the gas generated during the reaction process is reasonably distributed to the water production pipe or other required locations. In terms of liquid flow, the control valve equipped with the first liquid inlet pipe can accurately adjust the amount and timing of liquid entering the ultrafiltration membrane; at the same time, adding a second liquid inlet pipe between the first liquid inlet pipe and the water production pipe and implementing control through the control valve can help to flexibly adjust the reflux strategy, so that the ultrafiltration membrane can be cleaned and backwashed, thereby improving the overall flexibility and reliability of the equipment operation, thereby ensuring that the entire seawater desalination reverse osmosis brine residual pressure utilization process is more efficient and stable.

[0016] Optionally, two fixed parts are provided, the rotating part is rotatably connected between the two fixed parts, and a rotating seal is provided between the fixed part and the rotating part to achieve a rotational seal between the fixed part and the rotating part; the two fixed parts are respectively referred to as the first part and the second part, the residual pressure inlet, the concentrated brine inlet and the carbon dioxide waste gas inlet are opened on the first part, the outlet is opened on the second part, the second part is also provided with a first drain port opposite to the concentrated brine inlet and a second drain port opposite to the carbon dioxide waste gas inlet, the outlet is connected to a discharge pipe, the first drain port and the second drain port are both connected to the discharge pipe, the end of the discharge pipe away from the outlet is connected to the screening mechanism, and the first air intake pipe is connected to the discharge pipe.

[0017] By adopting the above technical solution, by dividing the fixed part into a first part and a second part and providing a rotating seal therebetween, good sealing between the rotating part and the fixed part is ensured, leakage of concentrated brine, carbon dioxide gas and other media is avoided, and the overall reliability of the device is improved. The first part is provided with a residual pressure inlet, a concentrated brine inlet and a carbon dioxide waste gas inlet, and the second part is provided with an outlet, a first drain port and a second drain port. This layout design is reasonable, which facilitates the flow of each medium along a predetermined path and participates in the reaction, thereby improving the reaction efficiency. The design in which the outlet, the first drain port and the second drain port are all connected to the discharge pipe effectively integrates a variety of outflow streams and simplifies the subsequent processing flow. In particular, the discharge pipe is finally connected to the screening mechanism, which further promotes the separation and utilization of the reaction products.

[0018] Optionally, the rotating seal includes a one-way valve installed in the reaction chamber and located at both ends of the reaction chamber, and a sealing ring installed at one end of the fixed part facing the rotating part. There are three sealing rings on each fixed part, and the three sealing rings on the first part are respectively mounted on the residual pressure inlet, the concentrated brine inlet and the carbon dioxide waste gas inlet; the three sealing rings on the second part are respectively mounted on the outlet, the first drain port and the second drain port.

[0019] By adopting this technical solution, the one-way valve effectively prevents backflow of materials within the reaction chamber, ensuring a stable reaction process. The sealing ring design enhances the sealing performance between the fixed and rotating parts, preventing leakage. Multiple sealing rings are installed on each inlet and outlet, further improving the sealing reliability of each channel. This can significantly reduce energy loss and material waste caused by leakage, especially during long-term operation or high-pressure conditions, thereby improving the efficiency and stability of the entire device.

[0020] Optionally, a mounting groove for mounting the sealing ring is provided on the fixing portion, and a tightening spring is fixedly connected between the bottom of the mounting groove and the sealing ring.

[0021] By adopting this technical solution, the retaining spring provides elastic support between the fixed and rotating parts, ensuring that the sealing ring fits tightly against the rotating surface, thereby enhancing the sealing performance of the rotary seal. This design effectively prevents leakage of the primary reverse osmosis brine, carbon dioxide gas, and secondary reverse osmosis residual pressure medium within the reaction chamber, ensuring the stability and reliability of the device's operation. Specifically, this structure optimizes the sealing effect, extends the equipment's service life, and provides more reliable protection for the entire seawater desalination reverse osmosis brine residual pressure utilization process.

[0022] Optionally, the residual pressure inlet includes a circular hole provided at an end of the first part away from the rotating part and an arc-shaped hole provided at an end of the first part toward the rotating part, and the arc-shaped hole is in communication with the circular hole.

[0023] By adopting this technical solution and providing a structure that connects the circular and arc-shaped holes, the angle flexibility of the residual pressure water flow into the reaction chamber can be effectively increased, ensuring that the residual pressure water can enter the reaction chamber smoothly at different positions of the rotating part, thereby improving the stability and reliability of the device operation. The arc-shaped hole design also helps to reduce the imbalance caused by the impact of the water flow on the rotating part, extending the service life of the device while improving energy transfer efficiency.

[0024] Optionally, the reaction mechanism also includes a rotational drive assembly for driving the rotating part to rotate, and a pressure dividing pipe is provided between the residual pressure inlet and the rotational drive assembly, and the pressure dividing pipe can transmit the pressure of the residual pressure inlet to the rotational drive assembly to provide a power source for the rotational drive assembly.

[0025] By adopting this technical solution, the high-pressure water flow from the residual pressure inlet is used as a power source to drive the rotary drive assembly, which in turn drives the rotating part. This not only achieves efficient energy recovery and reuse, but also reduces the need for external energy input.

[0026] Optionally, the rotary drive assembly includes a turbine, a generator connected to the turbine, a driving gear fixed to an output shaft of the generator, and a driven gear installed on the rotating part and meshing with the driving gear.

[0027] By adopting the above-mentioned technical solution, the rotary drive assembly consisting of a turbine and a generator can be used to effectively recover the residual pressure energy carried in the secondary reverse osmosis concentrated brine. Specifically, the residual pressure drives the turbine to operate, which in turn drives the generator to generate electricity, achieving efficient conversion and utilization of energy. At the same time, the meshing transmission of the driving gear and the driven gear ensures the stable rotation of the rotating part, so that the concentrated brine and carbon dioxide in the reaction chamber are fully mixed and reacted to generate solid calcium carbonate particles. This design not only improves the energy utilization rate, but also provides stable operation guarantee for the subsequent screening mechanism and cleaning mechanism, further enhancing the energy circulation effect and system stability of the entire device.

[0028] Optionally, the placement bin includes a support leg, a cylinder fixed on the support leg, and a discharge pipe fixed on the lower end of the cylinder, the discharge pipe is connected to the first liquid inlet pipe, a switch valve is installed on the discharge pipe, and a conveying pipe for conveying the solid particles screened by the screening mechanism into the cylinder is fixed between the screening mechanism and the cylinder.

[0029] By adopting the above technical solution, effective storage and transportation of solid particles of appropriate size after screening is achieved. Specifically, the design of the legs and the cylinder ensures the stable storage of solid particles, and the connectivity between the discharge pipe and the first liquid inlet pipe enables the solid particles to be accurately transported to the ultrafiltration membrane for friction washing under the action of the secondary reverse osmosis residual pressure, thereby effectively removing pollutants on the membrane surface. In addition, the setting of the switch valve facilitates the control of the release timing of the solid particles and improves operational flexibility. The delivery pipe ensures a close connection between the screening mechanism and the placement bin, ensuring that the screened solid particles can accurately enter the placement bin, further improving the working efficiency and reliability of the entire device.

[0030] In summary, this application includes at least one of the following beneficial technical effects:

[0031] The residual pressure of clean, fresh brine generated by the secondary reverse osmosis process is used to provide a high-pressure reaction environment, prompting the primary reverse osmosis concentrated brine to react efficiently with carbon dioxide to form calcium carbonate solid particles. This achieves efficient utilization of the residual pressure energy, avoids energy waste, and reduces the impact of direct discharge of the primary reverse osmosis concentrated brine on the marine ecological environment.

[0032] The clean, fresh brine produced by the secondary reverse osmosis process and the residual pressure energy contained therein are used to drive the production of calcium carbonate solid particles generated by the primary reverse osmosis concentrated brine and carbon dioxide. These particles are then used to enhance the cleaning process of the ceramic ultrafiltration membranes. This effectively solves the problem of ceramic ultrafiltration membrane fouling and clogging under harsh influent conditions (such as jellyfish outbreaks), thereby improving the system's operating efficiency and the service life of the membrane elements.

[0033] The entire device is rationally designed, making full use of carbon dioxide in industrial exhaust gas and converting it into economic crops such as calcium carbonate and magnesium carbonate, thus achieving carbon dioxide capture and fixation, reducing greenhouse gas emissions, promoting the recycling of resources, and improving the overall economy and environmental protection of the seawater desalination process. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of this application.

[0035] Figure 2 This is a schematic diagram made for submitting the reaction mechanism structure.

[0036] Figure 3 This is a cross-sectional diagram after the explosion, which is made to show the internal structure of the reaction mechanism.

[0037] Figure 4 yes Figure 3 Enlarged schematic diagram of point A in the middle.

[0038] Figure 5 This is a schematic diagram to reflect the structure of the cleaning mechanism.

[0039] Explanation of Reference Numerals: 1. Reaction mechanism; 11. Fixed portion; 111. First portion; 1111. Concentrated brine inlet; 1112. Residual pressure inlet; 1113. Carbon dioxide waste gas inlet; 112. Second portion; 1121. Outlet; 1122. First drain port; 1123. Second drain port; 1124. Circular hole; 1125. Arc-shaped hole; 1126. Connecting pipe; 12. Rotating portion; 121. Reaction chamber; 13. Rotating seal; 131. One-way valve; 132. Sealing ring; 133. Mounting groove; 134. Clamping spring; 14. Rotary drive assembly; 141. Turbine; 142. Generator; 143. Driving gear; 144. Driven gear; 15. Pressure dividing pipe; 16. Discharge pipe; 17. Connecting assembly; 171. Limiting ring; 172. Snap ring; 173. Tightening bolt; 174. Abutting ring; 175. Force spring; 2. Screening mechanism; 3. Cleaning mechanism; 31. Storage bin; 311. Support legs; 312. Cylinder body; 313. Discharge pipe; 314. Switch valve; 315. Delivery pipe; 32. First liquid inlet pipe; 33. First air inlet pipe; 34. Second liquid inlet pipe; 35. Second air inlet pipe; 4. Ultrafiltration membrane; 41. Filter cartridge; 42. Ceramic membrane; 43. Water inlet pipe; 44. Water production pipe; 45. Concentrated water discharge pipe; 46. Sewage pipe. DETAILED DESCRIPTION

[0040] The following is combined with Figure 1-5 This application is described in further detail.

[0041] During jellyfish outbreaks, strengthening the forward and backwash processes for both organic and ceramic ultrafiltration membranes is crucial for ensuring stable ultrafiltration membrane operation. This eliminates concentration polarization on the membrane surface and promptly removes jellyfish colloids from the inlet channel. By leveraging the high mechanical strength, chemical stability, and pore size of ceramic ultrafiltration membranes, as well as the ceramic material's ability to withstand friction from solid particles like calcium carbonate, solid particles within a certain size range, generated by carbon dioxide and primary reverse osmosis brine, are introduced into the inlet channel of the ceramic ultrafiltration membrane. This is supplemented by high-pressure gas-assisted scrubbing, which is crucial for reducing the fouling and clogging effects of jellyfish colloids on the ceramic membrane.

[0042] The present application discloses a device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis. Figure 1 The device for utilizing the residual pressure of reverse osmosis brine for desalination of seawater includes a reaction mechanism 1 for driving the mixed reaction of carbon dioxide and primary reverse osmosis brine through the pressure of secondary reverse osmosis, a screening mechanism 2 for screening solid particles after the reaction of carbon dioxide and primary reverse osmosis brine, and a cleaning mechanism 3 connected between the secondary reverse osmosis and the ultrafiltration membrane 4 for flushing the ultrafiltration membrane 4 through the pressure of the secondary reverse osmosis. The cleaning mechanism 3 can transport the solid particles screened by the screening mechanism 2 to the ultrafiltration membrane 4 to frictionally flush the ultrafiltration membrane 4.

[0043] Reference Figure 2 and Figure 3The reaction mechanism 1 includes two fixed parts 11 and a rotating part 12 rotatably connected between the two fixed parts 11. The two fixed parts 11 are respectively called the first part 111 and the second part 112. The first part 111 is provided with a concentrated brine inlet 1111 for connecting to the first-level reverse osmosis, a residual pressure inlet 1112 for connecting to the second-level reverse osmosis, and a carbon dioxide waste gas inlet 1113 for supplying carbon dioxide gas. The concentrated brine inlet 1111, the residual pressure inlet 1112 and the carbon dioxide waste gas inlet 1113 are arranged at intervals around the axis of the first part 111; the second part 112 is provided with an outlet 1121, a first drain port 1122 and a second drain port 1123. The outlet 1121, the first drain port 1122 and the second drain port 1123 are arranged at intervals around the axis of the second part 112. The residual pressure inlet 1112 and outlet 1121 are positioned opposite each other, the concentrated brine inlet 1111 and first drain port 1122 are positioned opposite each other, and the carbon dioxide waste gas inlet 1113 and second drain port 1123 are positioned opposite each other. The first drain port 1122, the second drain port 1123, and the outlet 1121 are connected. Reaction chambers 121 are formed through opposite ends of the rotating portion 12 and are offset from the axis of the rotating portion 12. When the rotating part 12 rotates, it will drive the reaction chamber 121 to rotate around the axis of the rotating part 12. When the reaction chamber 121 rotates to the point where both ends are connected to the residual pressure inlet 1112 and the outlet 1121, the water from the secondary reverse osmosis carrying the residual pressure will reach the reaction chamber 121 and push the water in the reaction chamber 121 to the outlet 1121 and out. As the rotating part 12 rotates, both ends of the reaction chamber 121 will be connected to the concentrated brine inlet 1111 and the first drain port 1122. At this time, the concentrated brine from the primary reverse osmosis will reach the reaction chamber 121 and push the water in the reaction chamber 121 to be discharged from the first drain port 1122. Then, as the rotating part 12 rotates again, the reaction chamber 121 will rotate to the point where both ends are connected to the carbon dioxide waste gas inlet 1113 and the second drain port 1123. At this time, carbon dioxide also enters the reaction chamber 121 and mixes with the concentrated brine in the reaction chamber 121, thereby reacting to generate insoluble carbonates mainly composed of calcium carbonate and magnesium carbonate. If the pressure in the reaction chamber 121 is too high due to the introduction of carbon dioxide, the water in the reaction chamber 121 will be discharged from the first drain port 1122 to achieve pressure relief. This achieves the treatment of carbon dioxide and concentrated brine. Finally, as the rotating part 12 continues to rotate, when the reaction chamber 121 rotates again to be connected to the residual pressure inlet 1112 and the outlet 1121, as water with a higher residual pressure flows into the reaction chamber 121, the carbonate generated by the mixing of carbon dioxide and concentrated brine in the reaction chamber 121 and the remaining water flow out from the outlet 1121. This achieves the residual pressure of the secondary reverse osmosis to provide power for the mixing of carbon dioxide and concentrated brine.

[0044] Among them, the concentrated brine is first introduced into the reaction chamber 121, and then the carbon dioxide is introduced into the reaction chamber 121. When the carbon dioxide is introduced into the reaction chamber 121 from the bottom, the carbon dioxide will be dissolved into the concentrated brine and move upward because it is lighter, so that the carbon dioxide and the concentrated brine are mixed more evenly and the reaction effect is better.

[0045] In order to improve the efficiency of the reaction between carbon dioxide and concentrated brine, a plurality of reaction chambers 121 may be provided spaced apart around the axis of the rotating part, so that the plurality of reaction chambers 121 can simultaneously realize the reaction operation between carbon dioxide and concentrated brine.

[0046] Among them, the residual pressure inlet 1112, the concentrated brine inlet 1111, the carbon dioxide waste gas inlet 1113, the outlet 1121, the first drain port 1122 and the second drain port 1123 have the same structure, and the only difference is the opening position. This application takes the structure of the residual pressure inlet 1112 as an example for explanation.

[0047] Reference Figure 3 The residual pressure inlet 1112 includes a circular hole 1124 provided at the end of the fixed portion 11 away from the rotating portion 12 and an arc-shaped hole 1125 provided at the end of the fixed portion 11 toward the rotating portion 12. The circular hole 1124 and the arc-shaped hole 1125 are connected, so that when the rotating portion 12 rotates, the reaction chamber 121 can be connected to the residual pressure inlet 1112 for a longer time so that the water with residual pressure in the residual pressure inlet 1112 can fully flow into the reaction chamber 121.

[0048] At the same time, a rotary seal 13 for performing rotational sealing between the fixed part 11 and the rotating part 12 is provided at both ends of the two fixed parts 11 and the rotating part 12. The rotary seal 13 can realize rotational sealing between the fixed part 11 and the rotating part 12.

[0049] Reference Figure 3 and Figure 4The rotating seal 13 includes a one-way valve 131 installed in each reaction chamber 121 and located at both ends of the reaction chamber 121, and a sealing ring 132 installed on the end of the fixed part 11 facing the rotating part 12. The one-way valve 131 is set so that liquid and gas can only flow from the residual pressure inlet 1112, the concentrated brine inlet 1111, and the carbon dioxide waste gas inlet 1113 to the outlet 1121, the first drain port 1122, and the second drain port 1123. There are three sealing rings 132 on each fixed part 11. The three sealing rings 132 on the first part 111 are respectively mounted on the residual pressure inlet 1112, the concentrated brine inlet 1111, and the carbon dioxide waste gas inlet 1113. The three sealing rings 132 on the second part 112 are respectively mounted on the outlet 1121, the first drain port 1122, and the second drain port 1123. The setting of the one-way valve 131 can prevent the liquid in the reaction chamber 121 from flowing out of the reaction chamber 121 when the rotating part rotates, and the setting of the sealing ring 132 can seal the residual pressure inlet 1112, the concentrated brine inlet 1111 and the carbon dioxide waste gas inlet 1113, thereby preventing the liquid or gas in the residual pressure inlet 1112, the concentrated brine inlet 1111 and the carbon dioxide waste gas inlet 1113 from leaking out from between the fixed part 11 and the rotating part 12, thereby ensuring the rotation sealing performance between the fixed part 11 and the rotating part 12.

[0050] Reference Figure 4 A mounting groove 133 for mounting a sealing ring 132 is also provided on the fixed part 11, and a tightening spring 134 is fixed between the bottom of the mounting groove 133 and the sealing ring 132. Under the elastic force of the tightening spring 134, the sealing ring 132 can always be pressed against the rotating part 12 to ensure the seal between the fixed part 11 and the rotating part 12.

[0051] Reference Figure 3 and Figure 4 A connecting assembly 17 for connecting the fixed portion 11 and the rotating portion 12 is provided between each end of the fixed portion 11 and the rotating portion 12 .

[0052] The connecting assembly 17 includes a limiting ring 171 fixed to the outer wall of the rotating part 12 and a retaining ring 172 fixed to the side of the fixed part 11 facing the rotating part 12. A space for the limiting ring 171 to be embedded is formed between the retaining ring 172 and the end of the fixed part 11. By embedding the limiting ring 171 into the space between the retaining ring 172 and the fixed part 11, the axial position of the rotating part 12 and the fixed part 11 can be fixed without affecting the normal rotation of the rotating part 12.

[0053] To ensure a tighter fit between the rotating portion 12 and the fixed portion 11, a plurality of abutting bolts 173 are threadedly connected to the retaining ring 172 around its axis. An abutting ring 174 is placed in the space formed by the retaining ring 172 and the fixed portion 11. The abutting bolts 173 abut the abutting ring 174, and the limiting ring 171 is located between the abutting ring 174 and the end of the fixed portion 11. When the abutting bolts 173 are tightened, the abutting ring 174 pushes the limiting ring 171, thereby clamping the limiting ring 171 between the abutting ring 174 and the fixed portion 11. The tightness of the abutting bolts 173 can be adjusted to adjust the fit between the fixed portion 11 and the rotating portion 12.

[0054] At the same time, a force spring 175 is also provided on the tightening bolt 173, so that when the tightening degree of the tightening bolt 173 is adjusted, the force spring 175 can give the abutment ring 174 a force to move closer to the limiting ring 171, so that the fixed part 11 and the rotating part 12 fit tightly while still having a certain buffer margin.

[0055] Reference Figure 1 and Figure 2 The reaction mechanism 1 also includes a rotary drive assembly 14 for driving the rotating part 12 to rotate. A pressure dividing pipe 15 is connected between the residual pressure inlet 1112 and the rotary drive assembly 14, so that the pressure dividing pipe 15 can transmit the pressure of the residual pressure inlet 1112 to the rotary drive assembly 14, so as to realize that the water with residual pressure through secondary reverse osmosis provides a power source for the rotary drive assembly 14.

[0056] Specifically, the rotary drive assembly 14 includes a turbine 141, a generator 142 connected to the turbine 141, a driving gear 143 fixed to the output shaft of the generator 142, and a driven gear 144 mounted on the rotating portion 12 and meshing with the driving gear 143. The water discharged from the secondary reverse osmosis process, with residual pressure, partially enters the fixed portion 11 to propel the solid particles and water after the reaction of carbon dioxide and concentrated brine to the next process. The remaining water enters the turbine 141 to generate electricity, driving the rotating portion 12 to rotate, thus reusing the residual pressure.

[0057] Valves are installed on both the residual pressure inlet and the pressure-dividing pipeline 15 to control the flow of water with residual pressure flowing to the fixing portion 11 and the rotary drive assembly 14 .

[0058] Reference Figure 1A discharge pipe 16 is installed at the outlet 1121. The first drain port 1122 and the second drain port 1123 are respectively connected to the discharge pipe 16 via connecting pipes 1126, so that water discharged from the first drain port 1122 and the second drain port 1123 can reach the discharge pipe 16 through the connecting pipes 1126. In order to prevent water from the discharge pipe 16 from reaching the first drain port 1122 and the second drain port 1123 through the connecting pipes 1126 and affecting the outflow of liquid in the reaction space, one-way valves are installed on the discharge pipe 16 at the first drain port 1122 and the second drain port 1123, so that liquid can only flow from the first drain port 1122 and the second drain port 1123 to the discharge pipe 16.

[0059] Reference Figure 1 The screening mechanism 2 is connected to the discharge pipe 16 and is used to transport the solid particles and water after the reaction of carbon dioxide and concentrated brine discharged from the discharge pipe 16 to the screening mechanism 2, so as to separate the solid particles and water through the screening mechanism 2 and screen out solid particles with a size within a set range.

[0060] The screening mechanism 2 can use the three-stage screening device currently available on the market. Its specific structure and working principle are existing technologies and will not be described in detail in this application. It is equipped with three levels of screens. The aperture of the top screen is larger, which can screen out solid particles with a size larger than the set value; the aperture of the middle screen is smaller, which can screen out solid particles with a size within the set range; the bottom screen can be a multi-layer gauze that only allows water to pass through, so that the fine solid particles are blocked by the bottom gauze, while the water will pass through the gauze to the bottom, realizing the separation of water and solid particles. The solid particles that are screened out by the middle screen and whose size is within the set range are transported to the cleaning mechanism 3 to achieve the cleaning of the ultrafiltration membrane 4.

[0061] Reference Figure 5 The ultrafiltration membrane 4 that needs to be cleaned in this application refers to a ceramic ultrafiltration membrane 4, which has high chemical stability, strength and pressure resistance. The ultrafiltration membrane 4 includes a filter cartridge 41 and a ceramic membrane 42 installed in the filter cartridge 41. A water inlet pipe 43 is provided at the lower end of the filter cartridge 41, a water production pipe 44 is provided on one side of the upper end of the filter cartridge 41, and a concentrated water discharge pipe 45 is provided at the upper end of the filter cartridge 41. When in use, the water to be treated is passed into the filter cartridge 41 from the water inlet pipe 43. The suspended matter, colloidal substances, etc. in the water will flow from the inner hole of the ceramic membrane 42 to the concentrated water discharge pipe 45 and be discharged from the concentrated water discharge pipe 45; while the water and small molecular organic matter in the water will pass through the side wall of the ceramic membrane 42 and flow from the water production pipe 44 to the next process.

[0062] Reference Figure 5The cleaning mechanism 3 includes a placement bin 31 connected to the screening mechanism 2 for holding solid particles with a size within a set range, and a first liquid inlet pipe 32 connected to the secondary reverse osmosis. The placement bin 31 is connected to the side wall of the first liquid inlet pipe 32, so that the clean brine with a higher residual pressure discharged from the secondary reverse osmosis can reach the ultrafiltration membrane 4 to clean the ceramic membrane 42. In the process of the water in the secondary reverse osmosis reaching the ultrafiltration membrane 4, the solid particles in the placement bin 31 will also reach the first liquid inlet pipe 32, so that the solid particles are transported to the ultrafiltration membrane 4 together with the water of the secondary reverse osmosis, thereby realizing friction flushing of the ultrafiltration membrane 4.

[0063] The storage bin 31 includes a support leg 311, a cylinder 312 fixed to the support leg 311, and a discharge pipe 313 fixed to the lower end of the cylinder 312. The end of the discharge pipe 313 away from the cylinder 312 is connected to the first liquid inlet pipe 32 to achieve communication with the first liquid inlet pipe 32. At the same time, a switch valve 314 is installed on the discharge pipe 313. A delivery pipe 315 is fixed between the screening mechanism 2 and the cylinder 312. The delivery pipe 315 is connected to the upper side of the middle screen of the screening mechanism 2 to transport solid particles within a set size range screened by the screening mechanism 2 through the delivery pipe 315 to the first liquid inlet pipe 32. The water with a higher residual pressure flowing out of the secondary reverse osmosis will transport the solid particles reaching the first liquid inlet pipe 32 to the ultrafiltration membrane 4, thereby achieving friction cleaning of the ultrafiltration membrane 4.

[0064] Control valves are installed on both the first liquid inlet pipe 32 and the water inlet pipe 43, allowing the ultrafiltration membrane 4 to be switched between operating and cleaning mode. When the ultrafiltration membrane 4 is switched to the cleaning mode, the produced water pipe 44 is closed, the concentrated water discharge pipe 45 is opened, and the on-off valve 314 and the control valve on the first liquid inlet pipe 32 are opened, while the control valve on the water inlet pipe 43 is closed. At this point, high-pressure water discharged from the secondary reverse osmosis process can pass through the first liquid inlet pipe 32, carrying solid particles of a predetermined size to the ultrafiltration membrane 4, thereby cleaning the ultrafiltration membrane 4. The cleaned wastewater and solid particles are then discharged from the concentrated water discharge pipe 45.

[0065] Reference Figure 1 and Figure 5 In order to make the cleaning efficiency of the ultrafiltration membrane 4 higher, the cleaning mechanism 3 also includes a first air inlet pipe 33 connected between the outlet 1121 and the ultrafiltration membrane 4. Because the gas entering the reaction chamber 121 from the carbon dioxide waste gas inlet 1113 contains other gases such as oxygen in addition to carbon dioxide, the carbon dioxide in the gas mixes and reacts with the concentrated brine, and the remaining gas is discharged from the outlet 1121.

[0066] An exhaust valve is installed on the exhaust pipe 16, and one end of the first air inlet pipe 33 is installed at the exhaust valve outlet 1121. This allows the remaining gas discharged into the exhaust pipe 16 to be discharged through the exhaust valve and flow along the first air inlet pipe 33 into the ultrafiltration membrane 4, causing some of the water to be converted into bubbles. This allows the ultrafiltration membrane 4 to be cleaned simultaneously with the bubbles, solid particles, and water, making cleaning more convenient. Of course, a control valve is also installed on the first air inlet pipe 33 to control the on-off of the first air inlet pipe 33, thereby controlling the gas entering the ultrafiltration membrane 4.

[0067] Reference Figure 5 A second liquid inlet pipe 34 is connected between the first liquid inlet pipe 32 and the produced water pipe 44. This second liquid inlet pipe 34 is connected to the side of the control valve of the first liquid inlet pipe 32 that is away from the ultrafiltration membrane 4. A control valve for opening and closing the second liquid inlet pipe 34 is also installed on the second liquid inlet pipe 34. This allows the flow of water to the ultrafiltration membrane 4 to be controlled, allowing the water discharged from the secondary reverse osmosis process to flow either to the water inlet pipe 43 of the ultrafiltration membrane 4 for positive flushing of the membrane 4 or to flow to the produced water pipe 44 of the ultrafiltration membrane 4 for backwashing of the membrane 4.

[0068] Of course, a second air inlet pipe 35 can also be provided between the first air inlet pipe 33 and the water production pipe 44. The second air inlet pipe 35 is located on the side of the first air inlet pipe 33 away from the ultrafiltration membrane 4, and a control valve is also installed on the second air inlet pipe 35. This allows the opening and closing of the control valves on the first air inlet pipe 33 and the second air inlet pipe 35 to be controlled to control the flow direction of the gas, so that the ultrafiltration membrane 4 can be flushed with both bubbles and water during the backwashing process.

[0069] The implementation principle of the device for utilizing the residual pressure of concentrated brine from reverse osmosis for seawater desalination in an embodiment of the present application is as follows: Under normal conditions, the concentrated brine from the first-stage reverse osmosis and the carbon dioxide produced by an external chemical plant can be directly transported to the reaction chamber 121, and the residual pressure from the second-stage reverse osmosis ensures the normal reaction and transportation of the concentrated brine and carbon dioxide. After the reaction of the concentrated brine and carbon dioxide, solid calcium carbonate particles are generated. The generated solid particles are transported together with water to the screening mechanism 2, and the solid particles and water are separated by the screening mechanism 2. At the same time, the solid particles are screened and classified according to size. Solid particles with a size within the set range will arrive at the storage bin 31. When the ultrafiltration membrane 4 needs to be cleaned, the first water inlet pipe 43, the first air inlet pipe 33 and the switch valve 314 are directly opened, so that the water with a higher residual pressure discharged through the secondary reverse osmosis can transport solid particles and gases within a set size range to the ultrafiltration membrane 4, so that the ceramic membrane 42 of the ultrafiltration membrane 4 is friction-cleaned by solid particles, bubbles and water, so as to remove the colloid on the inner pore wall of the ceramic membrane 42; and if backwashing is required, the second water inlet pipe 43 and the second air inlet pipe 35 are directly opened, so that water and gas can be transported to the water production pipe 44, so that the water and bubbles can backwash the ceramic membrane 42.

[0070] It is understood that when cleaning the ceramic membrane 42, the concentrate discharge pipe 45 is opened and the production water pipe 44 is closed, so that the water and solid particles entering through the water inlet pipe 43 are directly discharged through the concentrate discharge pipe 45. When backwashing the ceramic membrane 42, the concentrate discharge pipe 45 is closed and the water inlet pipe 43 is opened, so that the water entering through the production water pipe 44 is discharged through the water inlet pipe 43.

[0071] In order to facilitate the smooth discharge of the water after backwashing, a sewage pipe 46 is connected to the water inlet pipe 43 so that the water after backwashing can be discharged from the sewage pipe 46.

[0072] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis, characterized in that: include: The reaction mechanism (1) comprises a fixed portion (11) and a rotating portion (12); the fixed portion (11) is provided with a concentrated brine inlet (1111) for connecting to the first-stage reverse osmosis, a residual pressure inlet (1112) for connecting to the second-stage reverse osmosis, a carbon dioxide waste gas inlet (1113) for allowing carbon dioxide gas to enter, and an outlet (1121); the residual pressure inlet (1112) and the outlet (1121) are respectively located at two ends of the rotating portion (12); a reaction chamber (121) is provided inside the rotating portion (12) and can be respectively communicated with the residual pressure inlet (1112), the concentrated brine inlet (1111), and the carbon dioxide waste gas inlet (1113) by the rotation of the rotating portion (12); Screening mechanism (2): connected to the outlet (1121), used for receiving solid particles and water discharged from the outlet (1121) after the reaction of concentrated brine and carbon dioxide, and outputting solid particles with a size within a set range after screening; The cleaning mechanism (3) comprises a storage bin (31) connected to the screening mechanism (2) for storing solid particles with a size within a set range and a first liquid inlet pipe (32) connected to the secondary reverse osmosis, the other end of the first liquid inlet pipe (32) being connected to the ultrafiltration membrane (4), the storage bin (31) being connected to the side wall of the first liquid inlet pipe (32), so that the water with residual pressure discharged through the secondary reverse osmosis drives the solid particles in the storage bin (31) to the ultrafiltration membrane (4) to perform friction washing on the ultrafiltration membrane (4); one end of the ultrafiltration membrane (4) is a water inlet pipe (43), and the other end is a water production pipe (44) and a concentrated water discharge pipe (45); the first liquid inlet pipe (32) is connected to the water inlet pipe (43).

2. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 1, characterized in that: The cleaning mechanism (3) further comprises a first air inlet pipe (33) communicating between the first air inlet pipe (33) and the water inlet pipe (43).

3. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 2, characterized in that: A second air inlet pipe (35) is provided between the first air inlet pipe (33) and the water production pipe (44), and control valves are installed on both the first air inlet pipe (33) and the second air inlet pipe (35); a second liquid inlet pipe (34) is provided between the first liquid inlet pipe (32) and the water production pipe (44), and control valves are installed on both the first liquid inlet pipe (32) and the second liquid inlet pipe (34).

4. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 2, characterized in that: Two fixed parts (11) are provided, and the rotating part (12) is rotatably connected between the two fixed parts (11). A rotary seal (13) is provided between the fixed part (11) and the rotating part (12) to achieve a rotational seal between the fixed part (11) and the rotating part (12); the two fixed parts (11) are respectively referred to as a first part (111) and a second part (112); the residual pressure inlet (1112), the concentrated brine inlet (1111) and the carbon dioxide waste gas inlet (1113) are provided on the first part (111), and the outlet (1121) is provided on the second part ( 112), the second part (112) is further provided with a first drain port (1122) opposite to the concentrated brine inlet (1111) and a second drain port (1123) opposite to the carbon dioxide waste gas inlet (1113), the outlet (1121) is connected to a discharge pipe (16), the first drain port (1122) and the second drain port (1123) are both connected to the discharge pipe (16), one end of the discharge pipe (16) away from the outlet (1121) is connected to the screening mechanism (2), and the first air inlet pipe (33) is connected to the discharge pipe (16).

5. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 4, characterized in that: The rotary seal (13) comprises a one-way valve (131) installed in the reaction chamber (121) and located at both ends of the reaction chamber (121), and a sealing ring (132) installed at one end of the fixed part (11) facing the rotating part (12). Three sealing rings (132) are provided on each fixed part (11). The three sealing rings (132) on the first part (111) are respectively sleeved on the residual pressure inlet (1112), the concentrated brine inlet (1111) and the carbon dioxide waste gas inlet (1113); and the three sealing rings (132) on the second part (112) are respectively sleeved on the outlet (1121), the first drain port (1122) and the second drain port (1123).

6. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 5, characterized in that: The fixing portion (11) is provided with a mounting groove (133) for mounting the sealing ring (132), and a tightening spring (134) is fixedly connected between the bottom of the mounting groove (133) and the sealing ring (132).

7. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 4, characterized in that: The residual pressure inlet (1112) comprises a circular hole (1124) provided at one end of the first part (111) away from the rotating part (12) and an arc-shaped hole (1125) provided at one end of the first part (111) facing the rotating part (12), wherein the arc-shaped hole (1125) and the circular hole (1124) are in communication.

8. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 1, characterized in that: The reaction mechanism (1) further comprises a rotary drive assembly (14) for driving the rotating part (12) to rotate. A pressure-dividing pipe (15) is provided between the residual pressure inlet (1112) and the rotary drive assembly (14). The pressure-dividing pipe (15) is capable of transmitting the pressure of the residual pressure inlet (1112) to the rotary drive assembly (14), thereby providing a power source for the rotary drive assembly (14).

9. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 8, characterized in that: The rotary drive assembly (14) includes a turbine (141), a generator (142) connected to the turbine (141), a driving gear (143) fixed to an output shaft of the generator (142), and a driven gear (144) mounted on the rotating portion (12) and meshing with the driving gear (143).

10. The device for utilizing excess pressure of concentrated brine from seawater desalination and reverse osmosis according to claim 1, characterized in that: The storage bin (31) comprises a support leg (311), a cylinder (312) fixedly connected to the support leg (311), and a discharge pipe (313) fixedly connected to the lower end of the cylinder (312); the discharge pipe (313) is in communication with the first liquid inlet pipe (32); a switch valve (314) is installed on the discharge pipe (313); and a delivery pipe (315) for delivering solid particles screened by the screening mechanism (2) to the cylinder (312) is fixedly connected between the screening mechanism (2) and the cylinder (312).

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