Nitrate removal device and method based on nitrate-selective low-pressure membranes

Abstract

The present application relates to a nitrate removal device and method based on nitrate selective low-pressure membrane, belonging to the technical field of water pollution treatment, comprising a pipeline chassis, a plurality of filter pipe racks are fixedly installed on the top of the pipeline chassis, a plurality of fixed pipe barrels are jointly clamped between the plurality of filter pipe racks, a reverse osmosis membrane is arranged on the inner wall of each of the plurality of fixed pipe barrels, and a blocking cover is threadedly connected to the left and right sides of the reverse osmosis membrane on the inner wall of each of the plurality of fixed pipe barrels, the present application realizes automatic pressure relief adjustment by utilizing internal water pressure change, can stably maintain the constant water pressure of water delivered to the nitrate selective low-pressure membrane, reduces the transmembrane pressure difference fluctuation, guarantees the stable water quality, and in the process of pressure stabilization and pressure relief, the device can synchronously drive the movement of the turbulence component through the mechanical linkage structure, disturb the water flow on the membrane surface, destroy the concentration polarization layer, avoid the enrichment of nitrate and hardness ions on the membrane surface and scale formation, and delay the membrane flux attenuation.

Description

Technical Field

[0001] This invention relates to the field of water pollution treatment technology, specifically to a nitrate removal device and method based on a nitrate-selective low-pressure membrane. Background Technology

[0002] Water pollution treatment includes various methods such as sedimentation, filtration, disinfection, adsorption, ion exchange, and biological treatment. Nitrate removal devices based on nitrate-selective low-pressure membranes are one of these methods. They utilize the selective separation characteristics of nanofiltration membranes to efficiently separate nitrates from wastewater at relatively low operating pressures, thereby achieving the effect of water pollution treatment.

[0003] However, traditional wastewater nitrate removal devices typically require connection to a water storage tank or wastewater delivery pipe. The water to be treated is pumped to the membrane filtration unit for filtration. During this process, the inlet water pressure fluctuates with the source water pressure, pipeline load, and pump operating conditions, making it difficult to maintain a stable operating pressure. This leads to unstable flow velocity and transmembrane pressure differential on the membrane surface, resulting in significant fluctuations in nitrate removal rate and difficulty in consistently meeting effluent quality standards. Furthermore, in traditional devices, water flow continuously washes the membrane surface along a fixed path and in a fixed direction, creating a relatively stable laminar boundary layer. This allows nitrates and hardness ions to continuously accumulate on the membrane surface, gradually forming scale, causing concentration polarization and membrane fouling. Ultimately, this leads to decreased membrane flux, increased filtration resistance, reduced nitrate removal efficiency, shortened membrane element lifespan, and increased equipment operation and maintenance costs.

[0004] To address the aforementioned issues, we propose a nitrate removal device based on a nitrate-selective low-pressure membrane. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention utilizes internal water pressure changes to achieve automatic pressure relief and regulation. This can stably maintain a constant water pressure delivered to the nitrate-selective low-pressure membrane, reduce transmembrane pressure fluctuations, ensure stable effluent quality, and further, during the pressure stabilization and relief process, the device can synchronously drive the movement of the turbulence-inducing components through a mechanical linkage structure to disturb the water flow on the membrane surface, disrupt the concentration polarization layer, prevent nitrate and hardness ions from accumulating and forming scale on the membrane surface, and delay membrane flux decay.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a nitrate removal device based on a nitrate-selective low-pressure membrane, comprising a pipeline base frame, a plurality of filter tube frames fixedly installed on the top of the pipeline base frame, a fixed tube cylinder being snapped together among the plurality of filter tube frames, a reverse osmosis membrane being provided on the inner wall of each of the plurality of fixed tube cylinders, a sealing cap being threadedly connected to the left and right sides of the inner wall of each of the plurality of fixed tube cylinders located on the reverse osmosis membrane, and an infusion assembly being provided on one side of the surface of each of the left side of the sealing cap.

[0007] The infusion assembly includes a liquid inlet connection pipe fixedly installed on the left side of the left sealing cover, and a liquid outlet connection pipe fixedly installed at the center of the right side of the right sealing cover. A sealing cone is slidably installed on the inner wall of the fixed tube on the side of the left sealing cover, and a pressure relief port is opened on the top of the sealing cone on the side of the sealing cone. A movable annular cavity is opened inside the sealing cone, and several push rods are slidably installed on the inner wall of the movable annular cavity.

[0008] The inner wall of the sealing cone extends integrally to form six fan-shaped extrusion plates. An adjusting rod is rotatably installed on the side of the fan-shaped extrusion plate near the moving annular cavity. The adjusting rod passes through the inner wall of the sealing cone and extends into the moving annular cavity. Its extended end is rotatably connected to the surface of the pushing rod. A turbulence component is provided at the end of several of the pushing rods away from the sealing cone.

[0009] Furthermore, a control unit is installed on the front side of the filter tube frame, and a pressure pump is fixedly installed on the top of the pipe base frame and on the front side of the filter tube frame. The pressure pump can ensure that the water pressure entering the fixed tube is stable and sufficient, ensuring the treatment effect of nitrate removal from sewage and the quality of effluent. Several pipelines are connected to the pipe base frame and the filter tube frame, which can ensure the stable and normal operation of the water filtration process in each fixed tube.

[0010] Furthermore, a main liquid inlet pipe is fixedly installed on the left end of several of the liquid inlet connecting pipes, and a pressure gauge is installed on the left side of the pipe wall of the main liquid inlet pipe. A main liquid outlet pipe is fixedly installed on the right end of several of the liquid outlet connecting pipes. Both the main liquid inlet pipe and the main liquid outlet pipe are used to connect to the external pipe network to ensure the smooth operation of the water treatment process.

[0011] Furthermore, the pressure relief port is a rectangular opening, and the sealing cone blocks the pressure relief port under normal conditions. A connecting pipe is fixedly installed on the surface of the fixed tube and on the periphery of the pressure relief port. One end of several of the connecting pipes is fixedly installed with a return vertical pipe, which is used to guide the overflow liquid back to the storage tank.

[0012] Furthermore, the reverse osmosis membrane is a core structure with a porous disc at one end, and its inner wall is provided with a filter cylinder structure. The inner wall of the reverse osmosis membrane is connected to one end of the liquid outlet connection pipe to ensure stable delivery of purified water.

[0013] Furthermore, one end of each of the aforementioned push rods penetrates one side surface of the reverse osmosis membrane and extends to the gap between the fixed tube and the reverse osmosis membrane. The turbulence-inducing component is disposed on the inner wall of the fixed tube and is located on the periphery of the reverse osmosis membrane, cooperating with the extended end of the push rod to achieve the turbulence-inducing action.

[0014] Furthermore, the turbulence assembly includes a turbulence cylinder and a spiral turbulence plate. The turbulence cylinder is fixedly installed on one end of several push rods. The inner wall of the fixed tube is provided with several limiting grooves on one side of the turbulence cylinder. A damping spring is fixedly installed on the inner wall of each limiting groove on the side away from the sealing cone. A limiting block is fixedly installed on the output end of the damping spring.

[0015] Furthermore, the spiral spoiler is spirally fixedly installed on the inner wall of the spoiler cylinder. To ensure corrosion resistance and structural strength, both the spoiler cylinder and the spiral spoiler are made of stainless steel. The surface of the limiting block is slidably connected to the inner wall of the corresponding limiting groove, and the surface of each limiting block is fixedly connected to the surface of the spoiler cylinder.

[0016] Furthermore, the inner wall of the sealing cone has a gradually decreasing aperture at the end away from the liquid filling connection pipe. This gradual structure ensures that the liquid delivered by the liquid filling connection pipe can drive the sealing cone to move axially.

[0017] The two ends of the adjusting rod are connected to the fan-shaped extrusion plate and the rotating connection of the pushing rod using a hole block structure, which can effectively ensure the structural stability during rotation. At the same time, the adjusting rod extends through the sealing cone to the connection position of the moving annular cavity, with sufficient deformation space to accommodate the slight deformation of the adjusting rod during rotation and avoid structural jamming. With the setting of the fan-shaped extrusion plate, even when the pressure inside the sealing cone is low, the force transmission through the fan-shaped structure can still drive the adjusting rod to drive the pushing rod to generate displacement, thereby driving the turbulence component to act, realizing continuous turbulence of the water flow entering the reverse osmosis membrane and ensuring the scale prevention effect.

[0018] The method of using a nitrate removal device based on a nitrate-selective low-pressure membrane includes the following steps:

[0019] Step 1: Connect the pipelines: Connect the main liquid inlet pipe and the main liquid outlet pipe to the pipeline base frame to ensure that the pipelines on the pipeline base frame and filter tube rack are properly connected;

[0020] Step 2: Start the device: Start the pressurization pump through the control unit to send water into the fixed tube through the main liquid supply pipe and the liquid supply connection pipe;

[0021] Step 3, Constant Pressure Turbulence: The water flow pushes the sealing cone to slide. When the water pressure exceeds the standard, the pressure relief port opens, and the overflow water flows back through the connecting pipe and the return vertical pipe. At the same time, the sealing cone drives the push rod through the fan-shaped extrusion plate and the adjusting connecting rod, which drives the turbulence cylinder and the spiral turbulence plate to turbulent the water flow around the reverse osmosis membrane.

[0022] Step 4: Filtration and Transportation: The treated water after denitrification by reverse osmosis membrane filtration is transported to the outside through the outlet connection pipe and the outlet main pipe;

[0023] Step 5: Monitoring and Maintenance: Monitor the pressure using pressure gauges and conduct regular inspections to ensure stable operation of the device.

[0024] Compared with the prior art, the present invention provides a nitrate removal device and method based on a nitrate-selective low-pressure membrane, which has the following beneficial effects:

[0025] 1. This device utilizes internal water pressure changes to achieve automatic pressure relief and regulation, which can stably maintain a constant water pressure delivered to the nitrate-selective low-pressure membrane, reduce transmembrane pressure fluctuations, ensure stable effluent quality, and ensure that the water quality meets standards. Furthermore, during the pressure stabilization and relief process, the device can synchronously drive the movement of the turbulence-inducing components through a mechanical linkage structure to disturb the water flow on the membrane surface, disrupt the concentration polarization layer, prevent nitrate and hardness ions from accumulating and forming scale on the membrane surface, and delay membrane flux decay.

[0026] 2. Even if the internal pressure fluctuations are small, the linkage mechanism can still drive the turbulence components through the micro-motion structure to continuously ensure the turbulence effect on the membrane surface, thereby improving the overall filtration stability and denitrification efficiency of the device and extending the service life of the membrane elements.

[0027] 3. By using a pressure gauge, the device can monitor the pressure value inside the device in real time, thereby avoiding the problem of blockage affecting water purification and further preventing damage to the internal structure of the device.

[0028] 4. Through the setting of the fan-shaped extrusion plate and the adjusting link, even if the water pressure is not high enough to push the sealing cone, the deformation of the fan-shaped extrusion plate can drive the adjusting link to move, thereby generating a turbulence effect. When the water pressure is high enough to push the sealing cone to move, the sealing cone can directly drive the turbulence component to move without affecting the normal operation of the turbulence. Attached Figure Description

[0029] Figure 1 This is a perspective view of the entire invention;

[0030] Figure 2 This is a perspective view of the fixed tube of the present invention;

[0031] Figure 3 This is a three-dimensional cross-sectional view of the fixed tube portion of the present invention;

[0032] Figure 4 for Figure 3 Enlarged structural diagram of section A in the middle;

[0033] Figure 5 for Figure 3 Enlarged structural diagram of section B;

[0034] Figure 6 This is a three-dimensional view of the reverse osmosis membrane of the present invention.

[0035] Figure 7 for Figure 6 Enlarged structural diagram of section C;

[0036] Figure 8 This is a vertical sectional perspective view of the sealing cone of the present invention;

[0037] Figure 9 This is a perspective view of the unfolded fan-shaped extrusion plate of the present invention;

[0038] Figure 10 for Figure 9 A schematic diagram of the enlarged structure of D is shown below;

[0039] Figure 11 This is a perspective view of the spoiler tube of the present invention.

[0040] In the diagram: 1. Pipeline base frame; 2. Filter tube frame; 201. Control unit; 202. Booster pump; 3. Fixed tube; 4. Reverse osmosis membrane; 5. Sealing cap;

[0041] 6. Infusion assembly; 601. Infusion connection pipe; 6011. Infusion main pipe; 6012. Pressure gauge; 602. Outflow connection pipe; 6021. Outflow main pipe; 603. Sealing cone; 604. Pressure relief port; 605. Connecting pipe; 606. Return riser; 607. Moving annular cavity; 608. Pushing rod; 609. Sector-shaped extrusion plate; 610. Adjusting rod;

[0042] 7. Spoiler assembly; 701. Spoiler tube; 702. Spiral spoiler; 704. Limiting groove; 705. Damping spring; 706. Limiting block. Detailed Implementation

[0043] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0044] Please see Figures 1 to 11 The nitrate removal device based on the nitrate selective low-pressure membrane in this embodiment includes a pipe base 1, a plurality of filter tube frames 2 are fixedly installed on the top of the pipe base 1, and a fixed tube 3 is snapped together between the plurality of filter tube frames 2.

[0045] The inner walls of several fixed tubes 3 are provided with reverse osmosis membranes 4. The reverse osmosis membrane 4 is a core tube structure with a porous disc at one end and a filter tube structure on its inner wall. Raw water enters the interior from the outside of the reverse osmosis membrane 4. Nitrates and other impurities in the water are intercepted. The purified water passes through the membrane layer and enters the interior of the reverse osmosis membrane 4. Finally, it flows out through the liquid outlet connection pipe 602 connected to the inner wall of the reverse osmosis membrane 4.

[0046] Several fixed tubes 3 have threaded plugs 5 on the left and right sides of the reverse osmosis membrane 4. A liquid delivery assembly 6 is provided on one side of the surface of the left plug 5, and a liquid outlet connection pipe 602 is fixedly installed at the center of the right plug 5.

[0047] The infusion assembly 6 includes a liquid inlet connection pipe 601 fixedly installed on the left side of the left side of the left sealing cover 5. The left ends of several liquid inlet connection pipes 601 are fixedly installed together to form a main liquid inlet pipe 6011. A pressure gauge 6012 is installed on the left side of the pipe wall of the main liquid inlet pipe 6011. The right ends of several liquid outlet connection pipes 602 are fixedly installed together to form a main liquid outlet pipe 6021. The main liquid inlet pipe 6011 is connected to an external water supply network, and the main liquid outlet pipe 6021 is connected to a treated water collection network.

[0048] A sealing cone 603 is slidably installed on the inner wall of the fixed tube 3 on one side of the left sealing cover 5. The diameter of the end of the inner wall of the sealing cone 603 away from the liquid filling connection tube 601 is gradually reduced to form a cone-shaped drainage surface, ensuring that the inflowing liquid can generate axial thrust on the sealing cone 603.

[0049] The top of the sealing cone 603 is provided with a pressure relief port 604. The pressure relief port 604 is a rectangular opening. Under normal conditions, the outer wall of the sealing cone 603 is attached to the inner wall of the fixed tube 3 to seal the pressure relief port 604. A connecting pipe 605 is fixedly installed on the surface of the fixed tube 3 and around the pressure relief port 604. One end of several connecting pipes 605 is fixedly installed with a return vertical pipe 606. The return vertical pipe 606 is used to guide the overflow liquid back to the original water storage tank.

[0050] The sealing cone 603 has a movable annular cavity 607 inside. Several pushing rods 608 are slidably installed on the inner wall of the movable annular cavity 607. The inner wall of the sealing cone 603 extends integrally to form six fan-shaped extrusion plates 609. Each fan-shaped extrusion plate 609 has an adjusting rod 610 rotatably installed on the side near the movable annular cavity 607. The adjusting rod 610 passes through the inner wall of the sealing cone 603 and extends into the movable annular cavity 607. Its extended end is rotatably connected to the surface of the pushing rod 608. Both ends of the adjusting rod 610 adopt a hole block structure to achieve rotatable connection, ensuring structural stability. Deformation space is reserved at the penetration point to avoid jamming.

[0051] One end of each of the several push rods 608 penetrates one side surface of the reverse osmosis membrane 4 and extends to the gap between the fixed tube 3 and the reverse osmosis membrane 4. The turbulence component 7 is disposed on the inner wall of the fixed tube 3 and is located on the periphery of the reverse osmosis membrane 4.

[0052] Specifically, the turbulence assembly 7 includes a turbulence cylinder 701 and a spiral turbulence plate 702. The spiral turbulence plate 702 is spirally fixedly installed on the inner wall of the turbulence cylinder 701. Both the turbulence cylinder 701 and the spiral turbulence plate 702 are made of 304 stainless steel to ensure corrosion resistance and structural strength. The turbulence cylinder 701 is fixedly installed on one end of several push rods 608. The inner wall of the fixed tube 3 is provided with several limiting grooves 704 on one side of the turbulence cylinder 701. A damping spring 705 is fixedly installed on the side of the inner wall of each limiting groove 704 away from the sealing cone 603. A limiting block 706 is fixedly installed at the output end of the damping spring 705. The surface of the limiting block 706 is slidably connected to the inner wall of the corresponding limiting groove 704, and the surface of each limiting block 706 is fixedly connected to the surface of the turbulence cylinder 701.

[0053] A control unit 201 is installed on the front side of the filter tube frame 2. A pressure pump 202 is fixedly installed on the top of the pipe base frame 1 and on the front side of the filter tube frame 2. The pressure pump 202 is electrically connected to the control unit 201 to ensure that the water pressure entering the fixed tube 3 is stable and sufficient. Several pipelines such as the liquid inlet main pipe 6011, the liquid outlet main pipe 6021, and the return vertical pipe 606 are connected to the pipe base frame 1 and the filter tube frame 2 to ensure that the water filtration process in each fixed tube 3 is stable and operates normally.

[0054] The method of using a nitrate removal device based on a nitrate-selective low-pressure membrane includes the following steps:

[0055] Step 1: Connect the pipelines: Connect the main liquid inlet pipe 6011 and the main liquid outlet pipe 6021 to the pipeline base 1 respectively, thereby ensuring that the pipelines on the pipeline base 1 and the filter tube rack 2 are properly connected;

[0056] Step 2: Start the device: Start the pressurization pump 202 through the control unit 201 to send water into the fixed tube 3 through the main liquid filling pipe 6011 and the liquid filling connection pipe 601;

[0057] Step 3, Constant Pressure Turbulence: The water flow pushes the sealing cone 603 to slide. When the water pressure exceeds the standard, the pressure relief port 604 opens, and the overflow water flows back through the connecting pipe 605 and the return vertical pipe 606. At the same time, the sealing cone 603 drives the push connecting rod 608 through the fan-shaped extrusion plate 609 and the adjusting connecting rod 610, which drives the turbulence cylinder 701 and the spiral turbulence plate 702 to turbulent the water flow around the reverse osmosis membrane.

[0058] Step 4, Filtration and Transportation: The treated water after filtration and denitrification through reverse osmosis membrane 4 is transported to the outside through outlet connection pipe 602 and outlet main pipe 6021;

[0059] Step 5: Monitoring and Maintenance: Monitor the pressure using pressure gauge 6012 and conduct regular inspections to ensure stable operation of the device.

[0060] The working principle of the above embodiments is as follows:

[0061] When using the device, first connect the main liquid supply pipe 6011 to the external sewage network to be treated, connect the main liquid outlet pipe 6021 to the external treated water delivery network, and connect the return riser pipe 606 to the external storage tank. Check the connection of all pipes on the pipe base 1 and the filter pipe rack 2 to ensure that the pipe connections are firm and leak-free. Check that the reverse osmosis membrane 4 in each fixed tube 3 is installed in place and that the threaded connection of the sealing cap 5 is tight to ensure that the fixed tube 3 is well sealed. Check the sliding flexibility of the sealing cone 603 and the rotation state of the adjusting rod 610 to ensure that there is no jamming. The limit block 706 and the limit groove 704 slide smoothly. The damping spring 705 is undamaged and has normal elasticity. This application highlights the innovative structure and does not elaborate too much on existing mature technologies, such as the control machine 201 and the connected water pipe network.

[0062] When the booster pump 202 is turned on, the raw water is diverted through the main liquid supply pipe 6011 to the liquid supply connection pipes 601 of each fixed pipe cylinder 3. The pressure gauge 6012 on the main liquid supply pipe 6011 displays the inlet water pressure in real time. After the wastewater to be treated enters the fixed pipe cylinder 3, it continuously impacts the inner wall of the sealing cone 603. Since the inner wall of the sealing cone 603 is gradually narrowed at the end away from the liquid supply connection pipe 601, the impact force of the water flow will be concentrated on the gradually narrowed inner wall of the sealing cone 603, which is converted into a driving force to push the sealing cone 603 to slide axially along the inner wall of the fixed pipe cylinder 3.

[0063] When the water pressure inside the fixed tube 3 exceeds the set value, the sealing cone 603 slides away from the left sealing cover 5 under the impact of the water flow. At this time, the rectangular pressure relief port 604 on the sealing cone 603 is opened, and the excess wastewater to be treated in the fixed tube 3 flows out through the pressure relief port 604, flows into the return vertical pipe 606 through the connecting pipe 605 on the surface of the fixed tube 3, and is finally guided back to the external storage tank, thereby achieving pressure relief and stabilization, and avoiding damage to the reverse osmosis membrane 4 and a decrease in nitrate removal rate due to excessive water pressure.

[0064] When the water pressure in the fixed tube 3 drops to the set range, the damping spring 705 in the limiting groove 704 generates an elastic restoring force, pushing the limiting block 706 to slide along the limiting groove 704 towards the sealing cone 603. The limiting block 706 drives the turbulence tube 701 to move synchronously. The turbulence tube 701 drives the sealing cone 603 to reset by pushing the connecting rod 608 and adjusting the connecting rod 610, and re-seals the pressure relief port 604. This cycle repeats continuously to maintain the water pressure in the fixed tube 3, ensure the filtration environment of the reverse osmosis membrane 4 is stable, and ensure that the effluent water quality meets the standards.

[0065] During the process of the sealing cone 603 sliding axially along the inner wall of the fixed tube 3, the six fan-shaped extrusion plates 609 extending integrally from its inner wall move synchronously with the sealing cone 603. Since the two ends of the adjusting rod 610 are rotatably connected to the fan-shaped extrusion plates 609 and the pushing rod 608 respectively through the hole block structure, the movement of the fan-shaped extrusion plates 609 will transmit the driving force to the pushing rod 608 through the adjusting rod 610, causing the pushing rod 608 to slide along the inner wall of the moving annular cavity 607.

[0066] The connecting rod 608 is extended to the end between the fixed tube 3 and the reverse osmosis membrane 4, which drives the turbulence cylinder 701 to slide synchronously along the limiting groove 704. The spiral turbulence plate 702 on the inner wall of the turbulence cylinder 701 slides with the turbulence cylinder 701, which spirally disturbs the wastewater flowing to the reverse osmosis membrane 4 in the fixed tube 3, breaks the laminar flow state of the water flow, and makes the water flow turbulent, so as to avoid the accumulation and scaling of nitrate and hardness ions on the surface of the reverse osmosis membrane 4, damage the concentration polarization layer, and delay the flux decay of the reverse osmosis membrane 4.

[0067] Even when the pressure fluctuation inside the fixed tube 3 is small, the fan-shaped extrusion plate 609 can convert the weak pressure into uniform force transmission through its own fan-shaped structure, which drives the adjusting rod 610 and pushes the connecting rod 608 to form a small displacement, thereby driving the turbulence component 7 to move slightly, maintaining continuous turbulence on the water flow, ensuring the anti-scaling effect, and solving the problem of weakened turbulence effect when the pressure of the traditional device is stable. At the same time, the deformation space reserved at the connection position of the adjusting rod 610 through the sealing cone 603 can adapt to the small deformation when the adjusting rod 610 rotates, further avoiding structural jamming and ensuring continuous and stable turbulence action.

[0068] After being disturbed by the spiral baffle 702, the wastewater to be treated flows evenly through the porous disc at one end of the reverse osmosis membrane 4. The porous disc diverts the water flow, allowing the water to contact the filter cartridge on the inner wall of the reverse osmosis membrane 4 evenly. The filter cartridge uses a nitrate-selective low-pressure membrane, which can selectively retain nitrates and some impurities in the water, thereby achieving nitrate removal and purification of wastewater, while allowing the treated water to pass through smoothly.

[0069] The purified water enters the interior of the reverse osmosis membrane 4. Since the inner wall of the reverse osmosis membrane 4 is connected to one end of the outlet connection pipe 602, the treated water flows out through the outlet connection pipe 602 and flows into the outlet main pipe 6021. Then, it is transported to the external treated water transportation network through the outlet main pipe 6021 to complete the nitrate removal treatment of the sewage and achieve stable transportation of the treated water.

[0070] During continuous operation of the device, the inlet water pressure is monitored in real time by the pressure gauge 6012 on the main liquid supply pipe 6011. If the pressure is abnormal, the operating condition of the booster pump 202 is adjusted in time by the control unit 201 to ensure stable water pressure. The operating status of each component is checked regularly, including the sliding flexibility of the sealing cone 603, the rotation status of the adjusting connecting rod 610, the wear of the turbulence component 7, the sealing performance of the sealing cover 5, and the sealing of the connection of each pipeline. Maintenance and replacement are carried out in a timely manner to ensure long-term stable operation of the device and extend its service life.

[0071] This application achieves simultaneous pressure stabilization and turbulence through the mechanical linkage of the sealing cone 603, the fan-shaped extrusion plate 609, the adjusting connecting rod 610, the pushing connecting rod 608, and the turbulence assembly 7. Even with small pressure fluctuations, continuous turbulence can be maintained, effectively preventing scaling on the surface of the reverse osmosis membrane 4. Through the selective filtration of the reverse osmosis membrane 4, nitrate removal and purification of wastewater are achieved. The coordinated work of all components ensures stable filtration quality and reliable operation of the device.

[0072] The installation, connection, or setting methods disclosed in this embodiment are all common mechanical connection methods. Any method that can achieve its beneficial effect can be implemented. In addition, the electrical components in this embodiment are all electrically connected to the main controller and the power supply. The main controller can be a conventional known device such as a computer that plays a control role. Those skilled in the art can control the electrical components through simple programming. Moreover, the existing disclosed power connection technology is also common knowledge in the field. Therefore, the specific structural composition and working principle will not be described in detail in this embodiment.

Claims

1. A nitrate removal device based on a nitrate-selective low-pressure membrane, comprising a pipe base (1), wherein a plurality of filter tube supports (2) are fixedly installed on the top of the pipe base (1), and a fixed tube cylinder (3) is clamped between the plurality of filter tube supports (2), characterized in that: The inner walls of several fixed tubes (3) are provided with reverse osmosis membranes (4), and the inner walls of several fixed tubes (3) are threaded with sealing caps (5) on the left and right sides of the reverse osmosis membranes (4). The surface of several left sealing caps (5) is provided with infusion components (6). The infusion assembly (6) includes a liquid inlet connection pipe (601) fixedly installed on the left side of the left sealing cover (5), and a liquid outlet connection pipe (602) fixedly installed at the center of the right side of the right sealing cover (5). A sealing cone (603) is slidably installed on the inner wall of the fixed tube (3) on the side of the left sealing cover (5), and a pressure relief port (604) is opened on the top of the sealing cone (603) on the side of the sealing cone (603). A movable annular cavity (607) is opened inside the sealing cone (603), and several push rods (608) are slidably installed on the inner wall of the movable annular cavity (607). The inner wall of the sealing cone (603) extends integrally to form six fan-shaped extrusion plates (609). An adjusting rod (610) is rotatably installed on the side of the fan-shaped extrusion plate (609) near the moving annular cavity (607). The adjusting rod (610) passes through the inner wall of the sealing cone (603) and extends into the moving annular cavity (607). Its extended end is rotatably connected to the surface of the pushing rod (608). A turbulence component (7) is provided at the end of several of the pushing rods (608) away from the sealing cone (603). The turbulence assembly (7) includes a turbulence cylinder (701) and a spiral turbulence plate (702). The turbulence cylinder (701) is fixedly installed at one end of a plurality of push rods (608). The inner wall of the fixed tube (3) is provided with a plurality of limiting grooves (704) on one side of the turbulence cylinder (701). A damping spring (705) is fixedly installed on the side of the inner wall of each limiting groove (704) away from the sealing cone (603). A limiting block (706) is fixedly installed at the output end of the damping spring (705). The spiral baffle (702) is spirally fixedly installed on the inner wall of the baffle cylinder (701). To ensure corrosion resistance and structural strength, both the baffle cylinder (701) and the spiral baffle (702) are made of (304) stainless steel. The surface of the limiting block (706) is slidably connected to the inner wall of the corresponding limiting groove (704), and the surface of each limiting block (706) is fixedly connected to the surface of the baffle cylinder (701).

2. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 1, characterized in that: A control unit (201) is provided on the front side of the filter tube frame (2), and a pressure pump (202) is fixedly installed on the top of the pipe base frame (1) and on the front side of the filter tube frame (2).

3. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 2, characterized in that: A liquid filling main pipe (6011) is fixedly installed on the left end of several liquid filling connecting pipes (601), and a pressure gauge (6012) is provided on the left side of the pipe wall of the liquid filling main pipe (6011). A liquid outlet main pipe (6021) is fixedly installed on the right end of several liquid outlet connecting pipes (602).

4. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 3, characterized in that: The pressure relief port (604) is a rectangular opening. The sealing cone (603) seals the pressure relief port (604) under normal conditions. A connecting pipe (605) is fixedly installed on the surface of the fixed tube (3) and on the periphery of the pressure relief port (604). A return vertical pipe (606) is fixedly installed at one end of several of the connecting pipes (605).

5. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 4, characterized in that: The reverse osmosis membrane (4) is a core structure with a porous disc at one end, and a filter cylinder structure is provided on its inner wall. The inner wall of the reverse osmosis membrane (4) is connected to one end of the liquid outlet connection pipe (602).

6. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 5, characterized in that: One end of each of the aforementioned push rods (608) penetrates one side surface of the reverse osmosis membrane (4) and extends to the gap between the fixed tube (3) and the reverse osmosis membrane (4). The turbulence-inducing component (7) is disposed on the inner wall of the fixed tube (3) and is located on the periphery of the reverse osmosis membrane (4), cooperating with the extended end of the push rods (608) to achieve the turbulence-inducing action.

7. The nitrate removal device based on a nitrate-selective low-pressure membrane according to claim 6, characterized in that: The inner wall of the sealing cone (603) is set with a gradually decreasing aperture at the end away from the liquid filling connection pipe (601). This gradual structure can ensure that the liquid delivered by the liquid filling connection pipe (601) can drive the sealing cone (603) to move axially. The two ends of the adjusting rod (610) are connected to the fan-shaped extrusion plate (609) and the pushing rod (608) by a hole block structure, which can effectively ensure the structural stability during the rotation process. At the same time, the adjusting rod (610) extends through the sealing cone (603) to the connection position of the moving ring cavity (607), with enough deformation space reserved to accommodate the slight deformation of the adjusting rod (610) during the rotation process.

8. A method for using a nitrate removal device based on a nitrate-selective low-pressure membrane, characterized in that: The nitrate removal device based on a nitrate-selective low-pressure membrane, as described in claim 7, is used in a method comprising the following steps: Step 1: Connect the pipelines: Connect the main liquid inlet pipe (6011) and the main liquid outlet pipe (6021) to the pipeline base (1) respectively, so as to ensure that the pipelines on the pipeline base (1) and the filter pipe rack (2) are properly connected; Step 2, Start the device: Start the pressurization pump (202) through the control unit (201) to send water into the fixed tube (3) through the main liquid filling pipe (6011) and the liquid filling connection pipe (601); Step 3, constant pressure turbulence: The water flow pushes the sealing cone (603) to slide. When the water pressure exceeds the standard, the pressure relief port (604) opens, and the overflow water flows back through the connecting pipe (605) and the return vertical pipe (606). At the same time, the sealing cone (603) drives the push rod (608) through the fan-shaped extrusion plate (609) and the adjusting connecting rod (610), which drives the turbulence cylinder (701) and the spiral turbulence plate (702) to turbulence the water flow around the reverse osmosis membrane (4). Step 4, Filtration and Transportation: The treated water after being filtered and denitrified by the reverse osmosis membrane (4) is transported to the outside through the outlet connection pipe (602) and the outlet main pipe (6021); Step 5, Monitoring and Maintenance: Monitor the pressure using pressure gauge (6012), conduct regular inspections, and ensure stable operation of the device.

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