Double-membrane seawater desalination and water regeneration device and method

Abstract

The invention discloses a double-membrane seawater desalination and water regeneration device and method, and particularly relates to the field of water treatment.The double-membrane seawater desalination and water regeneration device comprises ultrafiltration units and reverse osmosis units, the ultrafiltration units are longitudinally arranged and communicated with the transversely arranged reverse osmosis units through bent pipes, and the water inlet ends of the ultrafiltration units are fixedly communicated with T-shaped pipes; a left side port of the T-shaped pipe is fixedly communicated with a water inlet pipe I through a flange, a right side port of the T-shaped pipe is fixedly communicated with a water inlet pipe II through a flange, and a switching valve is fixedly mounted on the T-shaped pipe. The T-shaped pipe can achieve independent water inlet or combined water inlet switching of the first water inlet pipe and the second water inlet pipe through the switching valve, seawater to be treated can be connected into the first water inlet pipe, regenerated water raw water can be connected into the second water inlet pipe, and independent treatment or mixed treatment of the two water sources is achieved by adjusting the opening degree of the switching valve. The double-working-condition operation requirements of seawater desalination and reclaimed water preparation are met; therefore, the effect of freely switching water inlet sources is achieved.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a dual-membrane seawater desalination and reclaimed water apparatus and method. Background Technology

[0002] The dual-membrane method (ultrafiltration + reverse osmosis) is currently the mainstream technology for seawater desalination and deep treatment of reclaimed water. The ultrafiltration unit can effectively remove impurities such as suspended solids, colloids, and microorganisms from the raw water and play a pre-protective role for the reverse osmosis membrane. The reverse osmosis unit can further remove salt, heavy metals, and dissolved organic matter from the water, achieving deep purification of the water body. It is widely used in water treatment scenarios such as coastal water supply and reclaimed water reuse.

[0003] Chinese patent publication number CN114940530B discloses a modular integrated water treatment device, filed on June 10, 2022. This patented technology, through an integrated pump-membrane design, eliminates the traditional membrane frame, significantly reducing the device's size and manufacturing cost, thereby improving its adaptability to different usage spaces and meeting the needs of customers with water treatment requirements but limited space. However, the aforementioned patent only has a single inlet pipe at the water inlet end, lacking a dual-source switching inlet structure, and cannot achieve flexible switching and mixing of seawater and reclaimed water, thus limiting its applicability. Therefore, this invention provides a dual-membrane seawater desalination and reclaimed water device and method to solve the problems mentioned in the background art. Summary of the Invention

[0004] The purpose of this invention is to provide a dual-membrane seawater desalination and reclaimed water device and method, thereby achieving the effect of freely switching the water source.

[0005] The objective of this invention can be achieved through the following technical solutions: A dual-membrane seawater desalination and reclaimed water device and method includes an ultrafiltration unit and a reverse osmosis unit. The ultrafiltration unit is arranged longitudinally and connected to the transversely arranged reverse osmosis unit through a bend in the pipe. A T-shaped pipe is fixedly connected to the inlet end of the ultrafiltration unit. The left port of the T-shaped pipe is fixedly connected to an inlet pipe one through a flange, and the right port of the T-shaped pipe is fixedly connected to an inlet pipe two through a flange. A switching valve is fixedly installed on the T-shaped pipe. A dosing mechanism is connected to the outlet end of the reverse osmosis unit.

[0006] As a further embodiment of the present invention: the dosing mechanism includes a dosing pipe, a water guide pipe is fixedly connected to the right side of the dosing pipe via a flange, and injection pipes are fixedly connected to the front and rear sides of the dosing pipe respectively. A push rod that moves in the same direction is slidably connected inside the two injection pipes, and a piston is fixedly connected to the inner end of the push rod, the piston being in contact with the inner wall of the injection pipe. A one-way valve is fixedly installed at the end of the injection pipe, which can only inject the liquid medicine in the injection pipe into the dosing pipe. A drug inlet pipe is fixedly connected to the left side of the injection pipe, and a drug storage tank is fixedly connected to the other end of the drug inlet pipe. A two-way valve is fixedly installed on the outside of the drug inlet pipe, which restricts the drug inlet pipe to only discharge the liquid medicine in the drug storage tank into the injection pipe.

[0007] As a further embodiment of the present invention: a fixing ring is fixedly connected to the left and right sides of the inside of the dosing tube, a cross bracket is fixedly connected inside the fixing ring, and a rotating shaft is connected to the center of the two cross brackets through a bearing. An impeller is fixedly connected to the left end of the rotating shaft, and a stirring paddle is fixedly connected to the outside of the rotating shaft.

[0008] As a further embodiment of the present invention: the left side of the dosing pipe is fixedly connected to an inclined pipe via a flange, and the left side of the inclined pipe is fixedly connected to the outlet end of the reverse osmosis unit via a flange.

[0009] As a further embodiment of the present invention: a disk is fixedly connected to the right end of the rotating shaft, and a connecting rod off-center is fixedly connected to the right side of the disk. A pair of connecting rods symmetrically distributed front and back are hinged to the outside of the connecting rods. An L-shaped rod is hinged to the other side of each of the two connecting rods. The L-shaped rod is divided into a horizontal rod and a vertical rod that are perpendicular to each other. The vertical rod passes through the dosing tube and the surface of the dosing tube is slidably connected to the vertical rod through a sealing sleeve. The horizontal rod is fixedly connected to the corresponding side push rod.

[0010] As a further embodiment of the present invention: the inside of the dosing tube is provided with a discharging mechanism, the discharging mechanism including a pair of transfer boxes fixedly connected to the front and rear sides of the inside of the dosing tube, the transfer boxes being connected to the discharging port of the dosing tube, the two transfer boxes being respectively fixedly connected to a connecting pipe, the inner sides of the two connecting pipes being fixedly connected to an annular pipe, the right side of the annular pipe having a set of circumferentially arranged discharging holes; the inside of the two transfer boxes being fixedly connected to an arc-shaped pipe, the right side of the arc-shaped pipe having a set of arc-shaped discharging holes, the inside of the transfer box being slidably connected to a sealing plate that can move left and right, the sealing plate being attached to the surface of the connection between the transfer box and the connecting pipe, and the sealing plate sealing the opening of the connecting pipe.

[0011] As a further embodiment of the present invention: a support ring is provided on the outer side of the rotating shaft, and the bottom of the support ring is fixedly connected to the dosing tube via a support frame. A movable ring that can move left and right is provided on the left side of the support ring. An annular guide rail is fixedly connected to the outer side of the movable ring. A rotating block is rotatably connected to the outer side of the annular guide rail. A connecting rod two is hinged to the outer side of the rotating block via a hinge. A slider is hinged to the other end of the connecting rod two. A slide rail is slidably connected to the left side of the slider. A turntable is fixedly connected to the left side of the slide rail. The turntable is fixedly connected to the rotating shaft. A driving rod is fixedly connected to the front and rear sides of the movable ring, respectively. The driving rod includes a vertical rod and a horizontal rod. The horizontal rod passes through the corresponding transfer box and is slidably connected to the transfer box, and a sealing sleeve is provided at the connection point. The right end of the horizontal rod is fixedly connected to a sealing plate.

[0012] As a further embodiment of the present invention: a support spring is fixedly connected to the left side of the support ring, and a movable ring is fixedly connected to the left side of the support spring.

[0013] As a further embodiment of the present invention: a pair of guide rods arranged in a front-to-back pattern are fixedly connected to the left side of the support ring, and the guide rods are slidably connected to the movable ring respectively.

[0014] This invention also proposes a dual-membrane method for seawater desalination and reclaimed water, comprising the following steps: S1. Seawater is pumped and transported from the ocean by a water pump. After being filtered by a preliminary filter to remove large-volume debris and silt, it is transported to the first water inlet pipe. The treated domestic sewage and industrial wastewater that meet the standards are collected and transported to the second water inlet pipe. Both types of raw water undergo pre-treatment with coarse filtration. S2. Adjust the switching valve on the T-tube to achieve precise switching of the inlet water source; when preparing desalinated seawater separately, open inlet pipe one and close inlet pipe two, and the pretreated seawater flows into the T-tube through inlet pipe one; when producing reclaimed water separately, open inlet pipe two and close inlet pipe one, and the reclaimed water raw water flows into the T-tube through inlet pipe two; the opening of the switching valve can also be finely adjusted to achieve proportional mixing of seawater and reclaimed water raw water; after the water intake is completed, the raw water is uniformly guided to the interior of the vertically arranged ultrafiltration unit; S3. After the raw water enters the ultrafiltration unit, it flows through the internal ultrafiltration membrane element. Under the physical sieving action of the ultrafiltration membrane, the remaining suspended solids, colloids, algae, microorganisms and macromolecular organic matter in the water are precisely removed, and various particulate impurities are intercepted. At the same time, the membrane element of the subsequent reverse osmosis unit is prevented from being contaminated and damaged. After ultrafiltration treatment, clean ultrafiltration water is obtained. S4. The ultrafiltration permeate flows from the longitudinal ultrafiltration unit to the transversely arranged reverse osmosis unit through the connecting bend. Under the selective permeation of the reverse osmosis membrane element, it efficiently removes salt, calcium and magnesium hardness ions, heavy metal ions and dissolved small molecule organic matter from the water, and completely completes the desalination and purification process to obtain salt-free, clean desalinated seawater or reclaimed water. The concentrate is discharged separately and collected through the concentrate end of the reverse osmosis unit. S5. The purified water after being treated by the reverse osmosis unit is discharged into the dosing unit, where an appropriate amount of chemical solution is added to adjust and stabilize the water quality. S6. Desalinated seawater or reclaimed water that has met the water quality standards is fully mixed in the dosing pipe and then discharged through the water pipe. Desalinated seawater can be directly used for domestic water, industrial water, and irrigation water, while reclaimed water is introduced into the corresponding reuse network, completing the entire process from raw water extraction to deep treatment and reuse of the produced water.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This dual-membrane seawater desalination and reclaimed water device and method allows for independent or combined water intake switching between inlet pipe one and inlet pipe two via a switching valve. Inlet pipe one can be connected to seawater to be treated, while inlet pipe two can be connected to raw reclaimed water. The opening degree of the switching valve can be adjusted to achieve separate or mixed treatment of the two water sources, meeting the dual-condition operation requirements of seawater desalination and reclaimed water preparation, thus achieving the effect of free switching of water sources.

[0016] Furthermore, in this dual-membrane seawater desalination and reclaimed water device and method, the two push rods moving in the same direction alternately push and pull. When the push rod is pulled outward, the internal volume of the injection tube increases, creating a negative pressure environment. To balance this negative pressure, the chemical solution in the storage tank enters the injection tube unidirectionally through the inlet pipe under atmospheric pressure, completing the absorption process. Conversely, when the push rod is pushed inward, the second one-way valve automatically closes, and the chemical solution inside the injection tube is pressurized to open the first one-way valve, injecting into the dosing tube to mix with the water treated by the dual-membrane method. Through the alternating push and pull motion of the push rods, the effect of quantitative chemical input is achieved. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a dual-membrane seawater desalination and reclaimed water device and method. Figure 2 This is a schematic diagram of the chemical dosing mechanism in a dual-membrane seawater desalination and reclaimed water device and method. Figure 3 This is a schematic cross-sectional view of the dosing mechanism in a dual-membrane seawater desalination and reclaimed water device and method. Figure 4 This is a schematic diagram of the internal structure of the dosing mechanism in a dual-membrane seawater desalination and reclaimed water device and method. Figure 5 This is a schematic diagram of the right side of the dosing mechanism in a dual-membrane seawater desalination and reclaimed water device and method; Figure 6 This is a schematic diagram of the chemical discharge mechanism in a dual-membrane seawater desalination and reclaimed water device and method. Figure 7 This is a schematic cross-sectional view of the chemical discharge mechanism in a dual-membrane seawater desalination and reclaimed water device and method.

[0018] In the diagram: 10. Ultrafiltration unit; 11. Reverse osmosis unit; 12. T-tube; 13. Switching valve; 14. Inlet pipe one; 15. Inlet pipe two; 16. Water guide pipe; 20. Dosing mechanism; 201. Dosing pipe; 202. Injection pipe; 203. Push rod; 204. Inlet pipe; 205. Storage tank; 206. Fixing ring; 207. Rotating shaft; 208. Impeller; 209. Disc; 210. Connecting rod one; 211. 212. L-shaped rod; 213. Stirring paddle; 30. Inclined tube; 30. Discharge mechanism; 301. Transfer box; 302. Connecting tube; 303. Arc-shaped tube; 304. Sealing plate; 305. Support ring; 306. Moving ring; 307. Support spring; 308. Guide rod; 309. Turntable; 310. Slide rail; 311. Slider; 312. Connecting rod II; 313. Rotating block; 314. Driving rod; 315. Annular tube. Detailed Implementation

[0019] like Figures 1-7 As shown, a dual-membrane seawater desalination and reclaimed water device and method includes an ultrafiltration unit 10 and a reverse osmosis unit 11. The ultrafiltration unit 10 is arranged longitudinally and connected to the transversely arranged reverse osmosis unit 11 through a bend. The inlet end of the ultrafiltration unit 10 is fixedly connected to a T-shaped pipe 12. The left port of the T-shaped pipe 12 is fixedly connected to an inlet pipe 14 through a flange, and the right port of the T-shaped pipe 12 is fixedly connected to an inlet pipe 25 through a flange. A switching valve 13 is fixedly installed on the T-shaped pipe 12. The outlet end of the reverse osmosis unit 11 is connected to a dosing mechanism 20.

[0020] The ultrafiltration unit 10 includes a longitudinally arranged membrane housing, an ultrafiltration membrane element, an end cap, and inlet / outlet water interfaces, used for pre-treatment filtration of raw water for suspended solids, colloids, and macromolecular organic matter; the reverse osmosis unit 11 includes a transversely arranged high-pressure membrane housing, a reverse osmosis membrane element, an end cap, and concentrate and permeate channels, used for desalination treatment of ultrafiltration permeate to obtain desalinated seawater or reclaimed water.

[0021] In use, the T-pipe 12 can switch between independent or combined water intake of inlet pipe 14 and inlet pipe 2 15 via switching valve 13. Inlet pipe 14 can be connected to seawater to be treated, and inlet pipe 2 15 can be connected to raw water for reclaimed water. The opening of switching valve 13 can be adjusted to achieve separate or mixed treatment of the two water sources, meeting the dual-condition operation requirements of seawater desalination and reclaimed water preparation. Raw water enters the longitudinally arranged ultrafiltration unit 10 through the T-pipe 12. Under the sieving action of the ultrafiltration membrane, colloids, particles and microorganisms in the water are removed, completing the first-stage purification. The ultrafiltration permeate flows through the bend pipe into the horizontally arranged reverse osmosis unit 11. Under the selective permeation action of the reverse osmosis membrane, salt, hardness ions and dissolved organic matter in the water are removed, resulting in qualified desalinated water or reclaimed water, completing the dual-membrane deep purification treatment.

[0022] refer to Figures 1-7 The dosing mechanism 20 includes a dosing pipe 201. A water guide pipe 16 is fixedly connected to the right side of the dosing pipe 201 via a flange. Injection pipes 202 are fixedly connected to the front and rear sides of the dosing pipe 201, respectively. A push rod 203 that moves in the same direction is slidably connected inside the two injection pipes 202. A piston is fixedly connected to the inner end of the push rod 203, and the piston is in contact with the inner wall of the injection pipe 202. A one-way valve is fixedly installed at the end of the injection pipe 202. The one-way valve can only inject the liquid medicine in the injection pipe 202 into the dosing pipe 201. A drug inlet pipe 204 is fixedly connected to the left side of the injection pipe 202. A drug storage tank 205 is fixedly connected to the other end of the drug inlet pipe 204. A one-way valve 2 is fixedly installed on the outside of the drug inlet pipe 204. The one-way valve 2 restricts the drug inlet pipe 204 to only discharge the liquid medicine in the drug storage tank 205 into the injection pipe 202.

[0023] During operation, the two push rods 203 moving in the same direction alternate between pushing and pulling. When push rod 203 is pulled outward, the internal volume of the injection tube 202 increases, creating a negative pressure environment. To balance this negative pressure, the liquid medicine in the storage tank 205 enters the injection tube 202 through the inlet pipe 204 under atmospheric pressure, completing the absorption process. Conversely, when push rod 203 is pushed inward, the one-way valve 2 automatically closes, and the liquid medicine inside the injection tube 202 is pressurized to open the one-way valve 1, injecting into the dosing tube 201 to mix with the water treated by the dual-membrane method. This alternating push-pull motion of push rod 203 ensures continuous and quantitative delivery of the liquid medicine, preventing interruptions or pulsating fluctuations and guaranteeing stable water quality. Furthermore, the amount of liquid medicine injected can be controlled based on the speed of push rod 203 movement.

[0024] Furthermore, fixing rings 206 are fixedly connected to the left and right sides of the inside of the dosing pipe 201, and cross brackets are fixedly connected inside the fixing rings 206. The center of the two cross brackets is connected to a rotating shaft 207 through bearings. An impeller 208 is fixedly connected to the left end of the rotating shaft 207, and an agitator 212 is fixedly connected to the outside of the rotating shaft 207. An inclined pipe 213 is fixedly connected to the left side of the dosing pipe 201 through a flange. The left side of the inclined pipe 213 is fixedly connected to the outlet of the reverse osmosis unit 11 through a flange.

[0025] After seawater or reclaimed water is treated by the ultrafiltration unit 10 and the reverse osmosis unit 11, it will be discharged to the dosing pipe 201 through the inclined pipe 213. The downward-sloping inclined pipe 213 can increase the water flow velocity and impact kinetic energy, so that the water flow can efficiently impact the surface of the impeller 208, drive the impeller 208 to rotate continuously, and then drive the rotating shaft 207 and the agitator 212 to rotate synchronously, so that the injected chemical solution and the purified water form turbulent mixing, increase the contact area and mixing uniformity between the chemical solution and the water, avoid local chemical solution concentrations that are too high or too low, and ensure that the subsequent water quality adjustment effect is uniform and stable. The chemical dosing unit 20 here mainly administers mineral conditioning agents to replenish the potassium, calcium, magnesium, and other minerals that the desalinated water lacks, thus improving the taste and drinking quality of the water. A subsequent chemical dosing unit 20 at the rear of the water pipe 16 is used to administer pH-adjusting agents, allowing for the precise adjustment of the water's pH value to the drinking water standard range. After disinfection and settling stabilization, the desalinated seawater can be directly used for domestic, industrial, and irrigation purposes, while the reclaimed water is introduced into the corresponding reuse network, completing the entire process from raw water extraction to deep treatment, multi-stage water quality control, and product water reuse.

[0026] Furthermore, a disk 209 is fixedly connected to the right end of the rotating shaft 207, and a connecting rod off-center is fixedly connected to the right side of the disk 209. A pair of connecting rods 210 symmetrically distributed front and back are hinged to the outside of the connecting rod. An L-shaped rod 211 is hinged to the other side of the two connecting rods 210 respectively. The L-shaped rod 211 is divided into a horizontal rod and a vertical rod that are perpendicular to each other. The vertical rod passes through the dosing tube 201 and the surface of the dosing tube 201 is slidably connected to the vertical rod through a sealing sleeve. The horizontal rod is fixedly connected to the corresponding side push rod 203.

[0027] When water flows and impacts the impeller 208, it causes the impeller 208 to rotate. The size of the water flow directly determines the rotation speed of the impeller 208. The larger the water flow, the greater the impact torque of the water flow on the impeller 208, and the higher the rotation speed of the impeller 208. The smaller the water flow, the smaller the impact torque, and the lower the rotation speed of the impeller 208. When the impeller 208 rotates, it drives the disc 209 to rotate synchronously via the rotating shaft 207. The eccentric rotation of the disc 209 drives the L-shaped rods 211 on both sides to move back and forth through the connecting rods 210 on both sides. The two L-shaped rods 211 move in the same direction, which in turn drives the push rods 203 on both sides to move in the same direction, completing the suction and injection of chemicals. When the water flow rate is larger, the impeller 208 rotates faster, the push rods 203 reciprocate at a higher frequency, and the amount of chemicals added per unit time is larger. When the water flow rate is smaller, the impeller 208 rotates slower, the push rods 203 move at a lower frequency, and the amount of chemicals added is smaller. This achieves the effect of adaptively adjusting the amount of chemicals according to the real-time water flow rate, realizing a precise match between the amount of chemicals and the amount of water to be treated.

[0028] When the above-mentioned dosing device dispenses drugs, since the injection pipe 202 is located on both sides of the dosing pipe 201 and the drug is dispensed asynchronously, the drug solution is injected from a fixed position on one side only. The contact position with the water body is singular, which can easily cause uneven local mixing and insufficient drug diffusion. Especially under high flow conditions, the drug mixing is prone to lag and the water quality adjustment is not timely. Therefore, a drug dispensing mechanism 30 is proposed.

[0029] refer to Figures 1-7 The dispensing mechanism 30 includes a pair of transfer boxes 301 fixedly connected to the front and rear sides of the inside of the dosing tube 201. The transfer boxes 301 are connected to the outlet of the dosing tube 202. The two transfer boxes 301 are respectively fixedly connected to the inside of the two transfer boxes 301. The inner sides of the two connecting tubes 302 are fixedly connected to an annular tube 315. The right side of the annular tube 315 has a set of circumferentially arranged dispensing holes. The inside of the two transfer boxes 301 is fixedly connected to an arc-shaped tube 303. The right side of the arc-shaped tube 303 has a set of arc-shaped dispensing holes. The inside of the transfer box 301 is slidably connected to a sealing plate 304 that can move left and right. The sealing plate 304 is attached to the surface of the connection between the transfer box 301 and the connecting tube 302, and the sealing plate 304 blocks the opening of the connecting tube 302.

[0030] Furthermore, a support ring 305 is provided on the outer side of the rotating shaft 207. The support ring 305 does not contact the rotating shaft 207, and its bottom is fixedly connected to the dosing tube 201 via a support frame. A support spring 307 is fixedly connected to the left side of the support ring 305, and a moving ring 306 is fixedly connected to the left side of the support spring 307. An annular guide rail is fixedly connected to the outer side of the moving ring 306, and a rotating block 313 is rotatably connected to the outer side of the annular guide rail. A connecting rod 2 is hinged to the outer side of the rotating block 313 via a hinge. 312, the other end of the connecting rod 312 is hinged to a slider 311, the slider 311 is slidably connected to a slide rail 310 on the left side, the slide rail 310 is fixedly connected to a turntable 309 on the left side, and the turntable 309 is fixedly connected to the rotating shaft 207; the front and rear sides of the moving ring 306 are respectively fixedly connected to a driving rod 314, the driving rod 314 includes a vertical rod and a horizontal rod, the horizontal rod passes through the corresponding transfer box 301 and is slidably connected to the transfer box 301 and a sealing sleeve is provided at the connection, and the right end of the horizontal rod is fixedly connected to the sealing plate 304.

[0031] Preferably, a pair of guide rods 308 arranged in a front-to-back pattern are fixedly connected to the left side of the support ring 305. The guide rods 308 are slidably connected to the moving ring 306, thereby achieving the effect of guiding and limiting the movement of the moving ring 306 and preventing the moving ring 306 from deflecting or getting stuck.

[0032] After the water flows through the dual-membrane method, the following situations may occur: the water flow is small and occupies less than half of the cross-section of the dosing pipe 201; the water flow is moderate and occupies more than half of the cross-section of the dosing pipe 201; the water flow is large and will occupy the entire cross-section of the dosing pipe 201.

[0033] When the first scenario occurs, the water flow impacting the surface of the impeller 208 will only cause the impeller 208 to rotate at a low speed. As a result, the rotating disc 309 at a low speed cannot use centrifugal force to make the slider 311 overcome the supporting force of the support spring 307 and slide outward along the slide rail 310. Therefore, the positions of the moving ring 306 and the driving rod 314 remain unchanged, and the sealing plate 304 still covers the opening of the connecting pipe 302. Therefore, when the liquid medicine enters the transfer box 301, it will only be discharged to the arc-shaped pipe 303 and finally discharged through a set of drain holes.

[0034] At this time, the dosing frequency of the dosing mechanism 20 is low and the amount of dosing per unit time is small. The small flow of water only occupies a local section of the dosing pipe 201. Using the arc-shaped pipe 303 to dispense the drug at a fixed point on one side can make a small amount of drug act precisely on the local water flow, avoiding the drug being dispersed to the waterless area and causing waste. This ensures that the drug concentration matches the water body under the small flow condition and improves the drug utilization rate.

[0035] In the second scenario, the impeller 208 rotates at a faster speed, causing the turntable 309 to rotate at the same frequency. The centrifugal force of the rotation overcomes part of the elastic force of the support spring 307, causing the slider 311 to slide outward along the slide rail 310 and revolve. This causes the moving ring 306 to move to the left via the connecting rod 312, while simultaneously causing the rotating block 313 to rotate synchronously along the annular guide rail. This, in turn, causes the support spring 307 to deform and the driving rod 314 to move to the left, causing the sealing plate 304 to move to the left to cover part of the opening of the connecting pipe 302 and part of the opening of the arc-shaped pipe 303. The amount of arc-shaped pipe 303 opening covered is proportional to the water flow impact force. At the same time, the size of the opening of the arc-shaped pipe 303 is the same as that of the opening of the connecting pipe 302. The moving displacement of the sealing plate 304 is linearly related to the centrifugal sliding distance of the slider 311, ensuring continuous and stable adjustment of the pipe opening. The liquid medicine entering the transfer box 301 will be diverted to the arc-shaped tube 303 and the connecting tube 302. The amount of diversion is proportional to the exposed part of the tube opening. Thus, the liquid medicine is discharged through the arc-shaped tube 303 and the ring tube 315 respectively and mixed with water.

[0036] At this time, the dosing frequency and dosage of the corresponding dosing mechanism 20 are moderate. The water body occupies most of the cross section of the dosing pipe 201. The use of arc-shaped pipe 303 and ring pipe 315 to divert the drug can expand the drug diffusion range, allowing the drug to be released simultaneously from a fixed point on one side and multiple points around the perimeter. This takes into account both the drug diffusion rate and the mixing uniformity, adapts to the mixing needs of medium flow water, and avoids local drug concentration imbalance.

[0037] When the third scenario occurs, the impeller 208 rotates at high speed, causing the slider 311 on the turntable 309 to slide to the outer end of the slide rail 310. This causes the moving ring 306 to move to the left limit via the connecting rod 312, which in turn causes the sealing plate 304 to move to the left via the driving rod 314, completely covering the opening of the arc-shaped tube 303. As a result, the liquid medicine entering the transfer box 301 enters the annular tube 315 through the connecting pipe 302 and is discharged through the liquid outlet.

[0038] At this time, the dosing mechanism 20 has a high dosing frequency and the largest dosing amount per unit time. The water fills the entire cross section of the dosing pipe 201. The use of the annular pipe 315 to uniformly dispense the drug in the circumferential direction can realize the synchronous diffusion of the agent along the entire cross section of the water flow. With the turbulent stirring effect of the agitator 212, a large amount of agent is fully and uniformly mixed with the large flow of water in a short time, avoiding the problem of untimely mixing of agents and local water quality failure under high flow, and ensuring that the water quality of the effluent from the dual-membrane method is stable and meets the standards.

[0039] This invention also proposes a dual-membrane method for seawater desalination and reclaimed water, comprising the following steps: S1. Seawater is pumped and transported from the ocean by a water pump. After being filtered by a preliminary filter to remove large-volume debris and silt, it is transported to the inlet pipe 14. The treated domestic sewage and industrial wastewater that meet the standards are collected and transported to the inlet pipe 25. Both types of raw water undergo pre-treatment with coarse filtration. S2. Adjust the switching valve 13 on the T-pipe 12 to complete the precise switching of the inlet water source; when preparing desalinated seawater alone, open the inlet pipe 14 and close the inlet pipe 2 15, and the pretreated seawater flows into the T-pipe 12 through the inlet pipe 14; when producing reclaimed water alone, open the inlet pipe 2 15 and close the inlet pipe 14, and the reclaimed water raw water flows into the T-pipe 12 through the inlet pipe 2 15; the opening of the switching valve 13 can also be finely adjusted to achieve the mixing of seawater and reclaimed water raw water in proportion; after the water intake is completed, the raw water is uniformly guided to the interior of the longitudinally arranged ultrafiltration unit 10; S3. After the raw water enters the ultrafiltration unit 10, it flows through the internal ultrafiltration membrane element. Under the physical sieving action of the ultrafiltration membrane, the remaining suspended solids, colloids, algae, microorganisms and macromolecular organic matter in the water are precisely removed, and various particulate impurities are intercepted. At the same time, the membrane element of the subsequent reverse osmosis unit 11 is prevented from being contaminated and damaged. After ultrafiltration treatment, clean ultrafiltration water is obtained. S4. The ultrafiltration permeate flows from the longitudinal ultrafiltration unit 10 to the interior of the transversely arranged reverse osmosis unit 11 through the connecting bend. Under the selective permeation of the reverse osmosis membrane element, salt, calcium and magnesium hardness ions, heavy metal ions and dissolved small molecule organic matter in the water are efficiently removed, and the desalination and purification treatment is completely completed to obtain salt-free and clean desalinated seawater or reclaimed water. The concentrate is discharged separately and collected through the concentrate end of the reverse osmosis unit 11. S5. The purified water treated by the reverse osmosis unit 11 is discharged into the dosing unit 20, where an appropriate amount of chemical solution is added to adjust and stabilize the water quality.

[0040] S6. Desalinated seawater or reclaimed water that has met the water quality standards is fully mixed in the dosing pipe 201 and then discharged through the water pipe. Desalinated seawater can be directly used for domestic water, industrial water, and irrigation water, while reclaimed water is introduced into the corresponding reuse network, completing the entire process from raw water extraction to deep treatment and reuse of the produced water.

[0041] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A dual-membrane seawater desalination and reclaimed water device, comprising an ultrafiltration unit (10) and a reverse osmosis unit (11), characterized in that, The ultrafiltration unit (10) is arranged longitudinally and connected to the transversely arranged reverse osmosis unit (11) through a bend. The inlet end of the ultrafiltration unit (10) is fixedly connected to a T-shaped pipe (12). The left port of the T-shaped pipe (12) is fixedly connected to an inlet pipe one (14) through a flange. The right port of the T-shaped pipe (12) is fixedly connected to an inlet pipe two (15) through a flange. A switching valve (13) is fixedly installed on the T-shaped pipe (12). The outlet end of the reverse osmosis unit (11) is connected to a dosing mechanism (20).

2. The dual-membrane seawater desalination and reclaimed water device according to claim 1, characterized in that, The dosing mechanism (20) includes a dosing pipe (201), with a water guide pipe (16) fixedly connected to the right side of the dosing pipe (201) via a flange. Injection pipes (202) are fixedly connected to the front and rear sides of the dosing pipe (201), respectively. A push rod (203) is slidably connected inside the two injection pipes (202). A piston is fixedly connected to the inner end of the push rod (203), and the piston fits against the inner wall of the injection pipe (202). A one-way valve is fixedly installed at the end of the injection tube (202), which can only inject the liquid medicine in the injection tube (202) into the dosing tube (201); the left side of the injection tube (202) is fixedly connected to the inlet tube (204), and the other end of the inlet tube (204) is fixedly connected to the storage tank (205). A one-way valve is fixedly installed on the outside of the inlet tube (204), which restricts the inlet tube (204) to only discharge the liquid medicine in the storage tank (205) into the injection tube (202).

3. The dual-membrane seawater desalination and reclaimed water device according to claim 2, characterized in that, The dosing tube (201) has fixed rings (206) fixedly connected to the left and right sides respectively. The fixed rings (206) have cross brackets fixedly connected inside. The center of the two cross brackets is connected to a rotating shaft (207) through a bearing. The left end of the rotating shaft (207) is fixedly connected to an impeller (208). The outside of the rotating shaft (207) is fixedly connected to a stirring paddle (212).

4. The dual-membrane seawater desalination and reclaimed water device according to claim 3, characterized in that, The left side of the dosing pipe (201) is fixedly connected to an inclined pipe (213) via a flange, and the left side of the inclined pipe (213) is fixedly connected to the outlet end of the reverse osmosis unit (11) via a flange.

5. A dual-membrane seawater desalination and reclaimed water device according to claim 4, characterized in that, A disc (209) is fixedly connected to the right end of the rotating shaft (207). A connecting rod off-center is fixedly connected to the right side of the disc (209). A pair of connecting rods (210) symmetrically distributed front and back are hinged to the outside of the connecting rod. An L-shaped rod (211) is hinged to the other side of the two connecting rods (210). The L-shaped rod (211) is divided into a horizontal rod and a vertical rod that are perpendicular to each other. The vertical rod passes through the dosing tube (201) and the surface of the dosing tube (201) is slidably connected to the vertical rod through a sealing sleeve. The horizontal rod is fixedly connected to the corresponding side push rod (203).

6. The dual-membrane seawater desalination and reclaimed water device according to claim 5, characterized in that, The dosing tube (201) is equipped with a discharging mechanism (30). The discharging mechanism (30) includes a pair of transfer boxes (301) fixedly connected to the front and rear sides of the dosing tube (201). The transfer boxes (301) are connected to the outlet of the dosing tube (202). The two transfer boxes (301) are respectively fixedly connected to connecting pipes (302). The inner sides of the two connecting pipes (302) are jointly fixedly connected to an annular pipe (315). The right side of the annular pipe (315) is... A set of circumferentially arranged medicine outlet holes are provided on the side; the interiors of the two transfer boxes (301) are connected by an arc-shaped tube (303), and a set of arc-shaped medicine outlet holes are provided on the right side of the arc-shaped tube (303). A sealing plate (304) that can move left and right is slidably connected inside the transfer box (301). The sealing plate (304) is attached to the surface of the connection between the transfer box (301) and the connecting tube (302), and the sealing plate (304) blocks the opening of the connecting tube (302).

7. A dual-membrane seawater desalination and reclaimed water device according to claim 6, characterized in that, A support ring (305) is provided on the outer side of the rotating shaft (207). The bottom of the support ring (305) is fixedly connected to the dosing tube (201) through a support frame. A movable ring (306) that can move left and right is provided on the left side of the support ring (305). An annular guide rail is fixedly connected to the outer side of the movable ring (306). A rotating block (313) is rotatably connected to the outer side of the annular guide rail. A connecting rod (312) is hinged to the outer side of the rotating block (313) through a hinge. A slider (311) is hinged to the other end of the connecting rod (312). The slider (311) is slidably connected to the slide rail (310) on the left side, and the slide rail (310) is fixedly connected to the turntable (309) on the left side. The turntable (309) is fixedly connected to the rotating shaft (207). The front and rear sides of the moving ring (306) are respectively fixedly connected to the driving rod (314). The driving rod (314) includes a vertical rod and a horizontal rod. The horizontal rod passes through the corresponding transfer box (301) and is slidably connected to the transfer box (301) with a sealing sleeve at the connection. The right end of the horizontal rod is fixedly connected to the sealing plate (304).

8. A dual-membrane seawater desalination and reclaimed water device according to claim 7, characterized in that, A support spring (307) is fixedly connected to the left side of the support ring (305), and a movable ring (306) is fixedly connected to the left side of the support spring (307).

9. A dual-membrane seawater desalination and reclaimed water device according to claim 8, characterized in that, A pair of guide rods (308) arranged in a front-to-back pattern are fixedly connected to the left side of the support ring (305), and the guide rods (308) are slidably connected to the moving ring (306).

10. A dual-membrane method for seawater desalination and reclaimed water, characterized in that, Includes the following steps: S1. Seawater from the ocean is pumped and transported by pumps. After being filtered by a preliminary filter screen to remove large-volume debris and silt, it is transported to the first inlet pipe (14). The treated domestic sewage and industrial wastewater that meet the standards are collected and transported to the second inlet pipe (15). Both types of raw water undergo front-end coarse filtration pretreatment. S2. Adjust the switching valve (13) on the T-tube (12) to complete the precise switching of the water source; when preparing desalinated seawater separately, open the first water inlet pipe (14) and close the second water inlet pipe (15), and the pretreated seawater flows into the T-tube (12) through the first water inlet pipe (14); when producing reclaimed water separately, open the second water inlet pipe (15) and close the first water inlet pipe (14), and the reclaimed water raw water flows into the T-tube (12) through the second water inlet pipe (15); the opening of the switching valve (13) can also be finely adjusted to achieve the mixing of seawater and reclaimed water raw water in proportion; after the water intake is completed, the raw water is uniformly guided to the interior of the longitudinally arranged ultrafiltration unit (10); S3. After the raw water enters the ultrafiltration unit (10), it flows through the internal ultrafiltration membrane element. Under the physical sieving action of the ultrafiltration membrane, the remaining suspended solids, colloids, algae, microorganisms and macromolecular organic matter in the water are precisely removed, and various particulate impurities are intercepted. At the same time, the membrane element of the subsequent reverse osmosis unit (11) is prevented from being contaminated and damaged. After ultrafiltration treatment, clean ultrafiltration water is obtained. S4. The ultrafiltration water is guided from the longitudinal ultrafiltration unit (10) to the interior of the transversely arranged reverse osmosis unit 11 through the connecting bend. Under the selective permeation of the reverse osmosis membrane element, salt, calcium and magnesium hardness ions, heavy metal ions and dissolved small molecule organic matter in the water are efficiently removed, and the desalination and purification treatment is completely completed to obtain salt-free and clean desalinated seawater or reclaimed water. The concentrated water is discharged separately from the concentrated water end of the reverse osmosis unit (11) for collection. S5. The purified water after treatment by the reverse osmosis unit (11) is discharged into the dosing mechanism (20) where the dosing mechanism adds an appropriate amount of chemical solution to adjust and stabilize the water quality. S6. Desalinated seawater or reclaimed water that has met the water quality standards is fully mixed in the dosing pipe 201 and then discharged through the water pipe. Desalinated seawater can be directly used for domestic water, industrial water, and irrigation water, while reclaimed water is introduced into the corresponding reuse network, completing the entire process from raw water extraction to deep treatment and reuse of the produced water.

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