Calcium ammonium nitrate wastewater treatment device and method

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a calcium ammonium nitrate wastewater treatment device and method.The device comprises a PH adjusting tank, a buffer tank, a heat exchanger, a multi-medium filter, a precision filter, a ceramic filter, an ultrafiltration device, a concentration reverse osmosis device, a desalination reverse osmosis device, a concentrated water reverse osmosis device and wastewater discharge system equipment; the multi-medium filter comprises a filter tank body, a fiber ball filter material layer is arranged in the filter tank body, and a liftable compression frame and bearing frame structure is arranged; the compression frame moves along the vertical guide pipe through a magnetic force driving mechanism, compresses the fiber balls to form a gradient pore structure during filtration, and moves upwards to release the fiber balls and trigger the dispersion frame to unfold during backwashing so as to assist in loose cleaning of the fiber balls; the compression frame is sleeved on a vertical guide pipe in the filter tank body in a lifting manner, and the bearing frame is movably hoisted at the bottom of the guide pipe; the device disclosed by the invention can efficiently realize graded purification and resource recovery.

Description

An ammonium calcium nitrate wastewater treatment device and method Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to an ammonium calcium nitrate wastewater treatment device and method. Background Technology

[0002] Calcium ammonium nitrate is a common nitrogen fertilizer, and its production process generates wastewater containing high concentrations of nitrates, ammonium ions, and calcium ions. Direct discharge of this wastewater can easily lead to eutrophication of water bodies, soil compaction, and pipe scaling, thus requiring effective treatment. Currently, the main methods for treating calcium ammonium nitrate wastewater include chemical precipitation, ion exchange, membrane separation, and biological denitrification.

[0003] Multi-media filters are widely used in industrial wastewater pretreatment due to their high filtration efficiency and stable operation. Traditional multi-media filters typically use quartz sand, anthracite, and activated carbon as filter media. However, when treating calcium ammonium nitrate wastewater containing suspended solids, colloids, and some dissolved pollutants, problems such as filter media caking and clogging easily occur, leading to decreased filtration efficiency and increased backwashing frequency. Fiber ball filter media, due to its large specific surface area, high porosity, and strong adsorption capacity, has been introduced into multi-media filtration systems to enhance the retention of fine suspended solids and colloidal substances.

[0004] However, fiber balls have the following problems in practical applications: The fiber balls have a radial structure, with denser fibers near the center, making it difficult for water to penetrate the central area during backwashing. This results in incomplete removal of trapped contaminants, leading to filter media fouling accumulation and reduced filtration efficiency over long-term operation. If air-water combined backwashing is used, the fiber balls, due to their low density, are easily washed out of the filter, causing filter media loss. When mechanical agitation is used for cleaning, the fiber balls are prone to breakage and fragmentation under shear force, damaging the filter media structure and shortening its service life. Summary of the Invention

[0005] The purpose of this invention is to provide an ammonium calcium nitrate wastewater treatment device and method to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a calcium ammonium nitrate wastewater treatment device, comprising a pH adjustment tank, a buffer tank, a heat exchanger, a multi-media filter, a precision filter, a ceramic filter, an ultrafiltration device, a concentration reverse osmosis device, a desalination reverse osmosis device, a concentrate reverse osmosis device, and a wastewater discharge system; the multi-media filter includes a filter tank containing a fiber ball filter media layer and equipped with a liftable compression frame and a support frame structure; the compression frame moves along a vertical guide tube via a magnetic drive mechanism, compressing the fiber balls to form a gradient pore structure during filtration, and releasing the fiber balls during backwashing and triggering the dispersion frame to unfold, thereby assisting in the loosening and cleaning of the fiber balls; the compression frame is lifted and sleeved on the vertical guide tube in the filter tank, and the support frame is movably suspended at the bottom of the guide tube; the compression frame can limit the support frame when compressing the fiber balls, and the support frame can vibrate under the action of the magnetic drive mechanism after the compression frame releases the fiber balls.

[0007] Preferably, the compression frame and the support frame are connected by an upper rotating rod and a lower rotating rod to form a dispersion frame. During backwashing, the compression frame moves upward to drive the dispersion frame to unfold and promote the dispersion of fiber balls.

[0008] Preferably, the compression frame is fixed to the guide tube by a pin mechanism. The pin mechanism includes a magnetic end, a movable frame, and a limiting rod. The magnetic force drives the movable frame to move to release the limiting rod from locking the positioning hole, thereby realizing the lifting and lowering control of the compression frame. The positioning hole is set on the side wall of the guide tube.

[0009] Preferably, a guide ring is provided in the middle of the compression frame, which is connected to the guide tube. A positioning seat is fixedly installed on the guide ring, and a magnetically controlled pin structure is provided in the positioning seat. A limiting rod is slidably installed in the positioning seat and is connected to the first spring. A slanted groove is provided at the bottom of the limiting rod, and a movable frame is movably installed in the positioning seat, and the movable frame is in contact with the slanted groove.

[0010] Preferably, the magnetic drive mechanism includes a waterproof box installed on the top of the filter tank, and the waterproof box is provided with an electromagnetic positive magnetic seat and a negative magnetic seat. By electromagnetic control, an attractive force or a repulsive force is applied to the magnetic end of the compression frame, driving the compression frame to move up and down on the guide tube.

[0011] Preferably, the load-bearing frame is movably mounted at the bottom of the guide tube, and a base is provided at the bottom of the guide tube. A lifting rod is connected to the middle of the load-bearing frame, and the lifting rod is slidably mounted in the base.

[0012] Preferably, the lifting rod is connected to a connecting rod that can extend into the guide tube. The top of the connecting rod is provided with a top block that is connected to a second spring in the guide tube. The top block can be blocked by a limiting rod inserted into the positioning hole.

[0013] Preferably, the lifting rod is movable in the base, and a horizontal rotating shaft is provided on the connecting rod. A magnetic plate and a gear are respectively connected to the two ends of the rotating shaft. A vertical rack is provided in the base and meshes with the gear. The magnetic plate can be driven by a magnetic drive mechanism, and the gear can drive the magnetic plate to rotate.

[0014] Preferably, a hanger is provided on the top of the filter tank, and the guide tube is vertically installed at the bottom of the hanger; the waterproof box is installed on the hanger.

[0015] Preferably, the top of the filter tank is connected to an upper inlet pipe, and the bottom is connected to a lower inlet pipe. A frame-type four-way pipe connects the upper inlet pipe and the lower inlet pipe. The frame-type four-way pipe has four channels, two of which are connected to the upper inlet pipe and the lower inlet pipe, and the other two are the water inlet and the sewage outlet. A water outlet pipe is connected to the lower inlet pipe. The inlet and outlet of wastewater and cleaning water are controlled by the channel structure of the frame-type four-way pipe and the valves installed on it.

[0016] A method for treating ammonium calcium nitrate wastewater includes the following steps: S1, the ammonium calcium nitrate process condensate is sequentially passed through a pH adjustment tank for pH adjustment, a buffer tank for temporary storage, and a heat exchanger for temperature adjustment; S2, the adjusted wastewater enters a multi-media filter for preliminary filtration to remove suspended solids and colloids; S3, the pre-filtered wastewater is sequentially passed through a precision filter and a ceramic filter for fine filtration; S4, the finely filtered wastewater enters an ultrafiltration unit for ultrafiltration treatment; S5, the ultrafiltration permeate enters a primary reverse osmosis system for primary reverse osmosis treatment, including: temporary storage in a primary reverse osmosis feed tank, pressurization by a primary reverse osmosis booster pump, filtration by a primary reverse osmosis security filter, and further pressurization by a primary reverse osmosis high-pressure pump before entering a primary reverse osmosis system. The first-stage reverse osmosis permeate enters the first-stage reverse osmosis permeate tank after processing by the first-stage reverse osmosis unit; S6, the first-stage reverse osmosis permeate enters the second-stage reverse osmosis system for further processing, including: pressurization by the second-stage reverse osmosis booster pump, filtration by the second-stage reverse osmosis security filter, pressurization by the second-stage reverse osmosis high-pressure pump, and processing by the second-stage reverse osmosis unit, with the permeate entering the reverse osmosis qualified water tank; S7, the water in the qualified water tank is transported to the point of use by the qualified water pump; S8, the first-stage reverse osmosis concentrate enters the concentrate treatment unit, including: temporary storage in the first-stage reverse osmosis concentrate tank, pressurization by the concentrate reverse osmosis high-pressure pump, and processing by the concentrate reverse osmosis unit, with the concentrate being recycled for the production of calcium ammonium nitrate by the reverse osmosis concentrate recovery pump.

[0017] Compared with existing technologies, the beneficial effects of this invention are: 1. In the pretreatment stage, this invention effectively removes suspended solids and colloids through a multi-media filter plus a precision filter and a ceramic filter, reducing the load on the subsequent membrane system. Subsequently, in the deep treatment stage, the combination of ultrafiltration and two-stage reverse osmosis ensures that the effluent ammonia nitrogen is ≤10mg / L and turbidity is ≤1NTU, meeting discharge standards. The concentrate reverse osmosis unit further concentrates the first-stage reverse osmosis concentrate for reuse in production, realizing the recycling of nutrients in the wastewater. The ultrafiltration and reverse osmosis devices adopt a low-flux design, extending membrane life and reducing the frequency of chemical cleaning.

[0018] 2. The multi-media filter achieves high-efficiency filtration and thorough backwashing. Through a liftable compression frame and support frame structure, the fiber ball filter media is compressed and loosened, solving the problem of traditional fiber balls being dense at the center and incomplete backwashing. The combination of the dispersion frame and vibration mechanism ensures the fiber balls are fully loosened during backwashing, avoiding mechanical damage and improving contaminant removal efficiency. A magnetically driven pin mechanism automatically locks and releases the compression frame, requiring no manual intervention and offering convenient operation. The fiber balls are cleaned under vibration and loosening conditions, preventing loss or breakage and extending filter media lifespan by more than 30%.

[0019] 3. The automatic switching of filtration, backwashing, and forward washing modes is achieved through the linkage of the frame-type four-way pipe and valve, reducing human operation errors. The online monitoring and control system is linked to adjust the operating parameters in real time to ensure stability. The modular design of the multi-media filter, such as the compression frame and the support frame, makes it easy to adjust the filter media combination or maintain and replace it according to the water quality. Attached Figure Description

[0020] Figure 1 is a flowchart of the processing method of the present invention.

[0021] Figure 2 is a schematic diagram of the overall multi-media filter of the present invention.

[0022] Figure 3 is a schematic diagram of the multi-media filter of the present invention in a semi-sectional state.

[0023] Figure 4 is a top view of the limiting frame structure of the present invention.

[0024] Figure 5 is a bottom schematic diagram of the limiting frame structure of the present invention.

[0025] Figure 6 is a schematic diagram of the distributed frame structure of the present invention.

[0026] Figure 7 is a schematic diagram of the compression frame structure of the present invention.

[0027] Figure 8 is a schematic diagram of the positioning seat structure of the present invention.

[0028] Figure 9 is a schematic diagram of the load-bearing frame structure of the present invention.

[0029] Figure 10 is a schematic diagram of the internal structure of the guide tube of the present invention.

[0030] Figure 11 is a schematic diagram of the lifting rod and connecting rod structure of the present invention.

[0031] In the diagram: 1. Filter tank; 2. Upper inlet pipe; 3. Lower inlet pipe; 4. Frame-type four-way pipe; 5. Outlet pipe; 6. Valve No. 1; 7. Valve No. 2; 8. Valve No. 3; 9. Valve No. 4; 10. Valve No. 5; 11. Hanger; 12. Guide pipe; 13. Compression frame; 14. Bearing frame; 15. Upper rotating rod; 16. Lower rotating rod; 17. Guide ring; 18. Positioning seat; 19. Positioning hole; 20. First spring; 21. Limiting rod; 22. Inclined groove; 23. Movable frame; 24. Magnetic end; 25. Waterproof box; 26. Positive magnetic seat; 27. Negative magnetic seat; 28. Base; 29. ​​Lifting rod; 30. Connecting rod; 31. Top block; 32. Second spring; 33. Magnetic plate; 34. Gear; 35. Rack. Detailed Implementation

[0032] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. It should be understood that the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0033] Please refer to Figures 1 to 11. The present invention provides a technical solution: a device and method for treating ammonium calcium nitrate wastewater.

[0034] During wastewater treatment, the content of 5Ca(NO3)2·NH4N3 in the wastewater is <1 g / L, of which Ca(NO3)2 content is <0.911 g / L, NH4NO3 content is <0.089 g / L, and calcium ion content is <0.222 g / L. Under normal circumstances, the feed rate is 2.5 m³ / L. 3 / h, maximum feed rate is 3.0 m 3 / h. After wastewater treatment, the requirements for the concentrated phase are: the concentration of salt (calcium ammonium nitrate) after concentration reaches about 5% to 10%, the discharge temperature is ≤50℃, and the discharge pressure is ~0.4MpaG. The requirements for the effluent quality are: the ammonia nitrogen content in the treated freshwater is 5 to 10 mg / l, the discharge temperature is ≤50℃, and the discharge pressure is ~0.4MpaG.

[0035] The ammonium nitrate calcium wastewater treatment unit includes: a pH adjustment tank, a buffer tank, a heat exchanger, a multi-media filter, a precision filter, a ceramic filter, an ultrafiltration unit, a concentration reverse osmosis unit, a desalination reverse osmosis unit, a concentrate reverse osmosis unit, and wastewater discharge system equipment; other auxiliary system equipment and water tanks and pumps; valves, pipes and accessories within the system; control equipment for each unit, local instruments and accessories. The equipment status and main process parameters of the wastewater treatment unit are sent to the control system in the wastewater treatment plant control room. The control system will handle equipment operation, interlock protection, alarms, and remote / local switching of equipment.

[0036] The main equipment capacity is provided as follows: two 5t / h pH adjustment tanks, one 5t / h heat exchanger, four 5t / h precision filters, two 5t / h ceramic filters, one 3.0t / h ultrafiltration unit, one 3.6t / h concentration reverse osmosis unit (including security filter, high-pressure pump, concentration reverse osmosis unit, internal piping, valves, accessories, instruments, instrument conduits, gas source pipes, instrument valves and gas source valves, pneumatic two-position valve box, power cabinet, programmable control cabinet, and cables and wiring for local instrument control equipment), one 2.3t / h desalination reverse osmosis unit (including high-pressure pump, desalination reverse osmosis unit, internal piping, valves, accessories, instruments, instrument conduits, gas source pipes, instrument valves and gas source valves, pneumatic two-position valve box, power cabinet, programmable control cabinet, and cables and wiring for local instrument control equipment), and one 1.3t / h... The concentrate reverse osmosis unit (including high-pressure pump, concentrate reverse osmosis unit, internal piping, valves, accessories, instruments, instrument conduits, air supply pipes, instrument valves and air supply valves, pneumatic two-position valve box, power cabinet, programmable control cabinet and cables and wiring for local instrument control equipment in the cabinet), 1 unit 5m 3 The first-stage reverse osmosis raw water tank, 1 5m 3 The first-stage reverse osmosis concentrate tank, 1 2m 3 Reverse osmosis concentrate tank, 1 5m 3 The package includes a qualified reverse osmosis water tank, one set of ultrafiltration reverse osmosis chemical cleaning equipment, all local indicating instruments (pressure gauges, local liquid level indicators for containers) and heat exchangers within the system, and all instruments and control devices (including instruments, instrument conduits, gas supply pipes, instrument valves and gas supply valves and accessories, control devices, and cables and wiring for local instrument control equipment in cabinets within the scope of supply) for the first-stage reverse osmosis, second-stage reverse osmosis, concentrate reverse osmosis, and electrodialysis units. All instrument selection is consistent with other parts of the wastewater treatment system.

[0037] The main process flow for wastewater treatment is as follows: ammonium nitrate calcium process condensate → pH adjustment tank → buffer tank → heat exchanger → multi-media filter → precision filter → ceramic filter → ultrafiltration unit → primary reverse osmosis feed tank → primary reverse osmosis booster pump → primary reverse osmosis security filter → primary reverse osmosis high-pressure pump → primary reverse osmosis unit → primary reverse osmosis product water tank → secondary reverse osmosis booster pump → secondary reverse osmosis security filter → secondary reverse osmosis high-pressure pump → secondary reverse osmosis unit → reverse osmosis qualified water tank → qualified water pump → point of use.

[0038] The concentrated reverse osmosis concentrate treatment process is as follows: primary reverse osmosis concentrate → primary reverse osmosis concentrate tank → concentrate reverse osmosis high-pressure pump → concentrate reverse osmosis unit → reverse osmosis concentrate recovery pump → ammonium nitrate calcium concentrate reuse point.

[0039] In the ammonium nitrate calcium wastewater treatment device, the filter medium of the multi-media filter is fiber balls. Fiber balls are filled into a container to form a bed. Because the individual fiber balls are relatively loose, the fiber filaments between them can interweave in the bed. At this point, the individual characteristics of the fiber balls are no longer important, and the bed forms a unified whole. The pressure on the fiber balls in the bed is the sum of the fluid resistance of the filtered water flow, the weight of the fiber balls themselves, and the weight of the suspended solids trapped. If the water flows through the bed from top to bottom, this force increases sequentially along the water flow direction in the filter layer. Due to the elasticity of the fiber balls, under pressure, the porosity and pore size of the filter layer gradually decrease, and the specific surface area of ​​the filter media gradually increases.

[0040] The filtration efficiency of multi-media filters using fiber balls increases progressively from low to high. Larger diameter suspended solids that are easily filtered out are retained by the upper filter layer, while smaller diameter suspended solids that are difficult to filter out are retained by the middle or lower filter layers. Throughout the filter layer, mechanical screening and contact flocculation are fully utilized, resulting in high filtration rate, high dirt-holding capacity, and good effluent quality. During filtration, the filter layer pores gradually decrease along the water flow direction, which closely matches the ideal pore distribution of larger pores at the top and smaller pores at the bottom of the filter media. This results in high efficiency, fast filtration rate, large dirt-holding capacity, and high organic matter removal rate. Backwashing with air and water is used, with a backwash volume of 1-2% of the filtered water volume.

[0041] Field test data on wastewater filtration using fiber balls show that when the operating flow rate is 25 km / h, the interception capacity is generally around 5 kg, which is several times that of sand filters. The effluent turbidity is significantly better than that of sand filters. However, considering the shortcomings of fiber balls as a medium—they are radially shaped spheres with dense fibers near the center, making it difficult to loosen them during backwashing, resulting in difficult-to-remove trapped contaminants; the fibers are easily lost during combined air and water cleaning; and they are easily broken during mechanical agitation—this invention's multi-media filter can compress and disperse the fiber ball medium, ensuring effective filtration and backwashing.

[0042] The multi-media filter of the present invention includes a filter tank 1, with an upper inlet pipe 2 connected to the top of the filter tank 1 and a lower inlet pipe 3 connected to the bottom. A frame-type four-way pipe 4 is connected between the upper inlet pipe 2 and the lower inlet pipe 3. The frame-type four-way pipe 4 is provided with four channels, two of which are connected to the upper inlet pipe 2 and the lower inlet pipe 3, and the other two are the water inlet and the sewage outlet. Wastewater and backwash water enter from the water inlet, while the dirty water during backwashing is discharged from the sewage outlet.

[0043] As shown in Figure 3, valves 6, 7, 8, and 9 are respectively installed on the frame-type four-way pipe 4 to control the inflow and outflow of wastewater, backwash water, and sewage. At the same time, an outlet pipe 5 is connected to the side of the lower inlet pipe 3, and valve 10 is connected to the outlet pipe 5. The filtered wastewater flows out from the outlet pipe 5. The specific wastewater pretreatment process is as follows: First, open valve 6 and valve 10. Wastewater enters the frame-type four-way pipe 4 from the inlet, then enters the filter tank 1 through the upper inlet pipe 2. After filtration, it flows out through the lower inlet pipe 3 and is discharged through the outlet pipe 5. Then, backwashing of the fiber ball media in the filter tank 1 is performed by opening valve 8 and valve 7. Backwash water enters from the inlet of the frame-type four-way pipe 4 and then enters the filter tank 1 through the lower inlet pipe 3. Wastewater after backwashing the media enters the frame-type four-way pipe 4 through the upper inlet pipe 2 and is discharged through the drain outlet. Finally, forward washing of the media is performed by opening valve 6 and valve 9. Clean water enters from the inlet of the frame-type four-way pipe 4 and enters the filter tank 1 through the upper inlet pipe 2. Wastewater after washing enters the frame-type four-way pipe 4 through the lower inlet pipe 3 and is discharged through the drain outlet.

[0044] The filter tank 1 of this invention is provided with a limiting frame structure consisting of a compression frame 13 and a support frame 14 for limiting the loading of fiber ball media. A hanger 11 is provided at the top of the filter tank 1, and a guide tube 12 is vertically installed at the bottom of the hanger 11. The compression frame 13 is movably sleeved on the guide tube 12, while the support frame 14 is movably suspended at the bottom of the guide tube 12. During filtration, the compression frame 13 is in a low position, enabling compression of the fiber balls to maintain a tight filtration state. During backwashing and forward washing, the compression frame 13 can be raised... The compression frame 13 is moved to a higher position, leaving space for the fiber balls to disperse and ensuring the cleaning effect. An upper rotating rod 15 is rotatably connected to the compression frame 13, and a lower rotating rod 16 is rotatably connected to the support frame 14. The upper rotating rod 15 and the lower rotating rod 16 are rotatably connected to form a dispersion frame. In the filtration state, the upper rotating rod 15 and the lower rotating rod 16 are respectively attached to the guide tube 12 and the support frame 14. In the cleaning state, due to the upward movement of the compression frame 13, the upper rotating rod 15 and the lower rotating rod 16 will rotate out to push the fiber balls and help them disperse. The pushing force will not damage the fiber balls.

[0045] A guide ring 17 is provided in the middle of the compression frame 13. The guide ring 17 is connected to the guide tube 12 for positioning. A positioning seat 18 is fixedly installed on the guide ring 17. The positioning seat 18 is provided with a magnetically controlled pin structure. The guide tube 12 is provided with a positioning hole 19. The connection between the pin structure and the positioning hole 19 can position the compression frame 13 in a low position, maintaining the compression of the fiber balls and ensuring its filtration effect. The pin structure includes a first spring 20 and a limiting rod 21 installed in the positioning seat 18. The limiting rod 21 is slidably installed in the positioning seat 18 and can be translated. The limiting rod 21 is connected to the first spring 20 and can pop out under the action of elastic force, thereby connecting with the positioning hole 19. At the same time, the bottom of the limiting rod 21 is provided with a slanted groove 22. A movable frame 23 is also movably installed in the positioning seat 18. The movable frame 23 is set through the positioning seat 18, and the top of the movable frame 23 is... The magnetic end 24 is installed. When the magnetic end 24 is magnetically attracted, it can cause the movable frame 23 to move upward and push the limiting rod 21 from the position of the inclined groove 22, so that the limiting rod 21 is pulled out from the positioning hole 19. Under the continuous magnetic attraction, it pulls the positioning seat 18 upward, thereby driving the compression frame 13 to move upward along the guide tube 12 to the high position. Conversely, when the magnetic end 24 is magnetically repelled, it can cause the compression frame 13 to reset and be fixed in the low position to maintain the compression of the limiting ball.

[0046] A waterproof box 25 is fixedly installed on the hanger 11. The electrical components are protected by the waterproof box 25. The bottom of the waterproof box 25 is provided with a positive magnetic base 26 and a negative magnetic base 27. Both are electromagnetic structures and can generate sufficiently large magnetic attraction and repulsion forces on the magnetic end 24 respectively, controlling the upward and downward movement of the compression frame 13.

[0047] The support frame 14 of the present invention is movably mounted at the bottom end of the guide tube 12, and has the ability to move within a small range. A base 28 is provided at the bottom of the guide tube 12, and a lifting rod 29 is connected to the middle of the support frame 14. The lifting rod 29 is slidably mounted in the base 28, and a connecting rod 30 is connected to the lifting rod 29. The connecting rod 30 can extend into the guide tube 12, and a top block 31 is provided at the top of the connecting rod 30. The top block 31 is connected to the second spring 32 in the guide tube 12, and the top block 31 can be inserted. The limiting rod 21, which enters the positioning hole 19, blocks the lifting rod 29, preventing it from moving. After the compression frame 13 moves to the high position, the obstruction on the top block 31 disappears, allowing the lifting rod 29 to move within a small range in the base 28. A horizontal rotating shaft is provided on the connecting rod 30, with a magnetic plate 33 and a gear 34 connected to both ends of the shaft. A vertical rack 35 is provided in the base 28, meshing with the gear 34. When the lifting rod 29 is in the low position, the magnetic plate 33 is also attracted by the magnetic force of the positive magnetic seat 26, thereby driving the lifting rod 29 and the support frame 14 to move upward. During the movement, the gear 34 rotates, causing the magnetic plate 33 to flip over. Subsequently, the magnetic plate 33 is repelled by the magnetic force of the positive magnetic seat 26, causing the lifting rod 29 and the support frame 14 to move downward. Therefore, after the compression frame 13 moves upward, the support frame 14 can vibrate within a small range, and the dispersion frame formed by the upper rotating rod 15 and the lower rotating rod 16 will also vibrate within a small range, making the fiber balls looser and easier to clean.

[0048] The ultrafiltration unit uses high-quality ultrafiltration membranes. Based on the raw water quality and ease of cleaning during operation, the ultrafiltration membranes utilize membrane elements with good mechanical strength, high membrane flux, good chemical stability, and high-quality permeate. The water station's influent is considered to have relatively poor water quality, and a reasonable design flux is selected to ensure the long-term normal operation of the membrane elements and a reasonable cleaning cycle. The design water flux of the membrane elements should be selected according to the lower of the specified water flux values, requiring a membrane flux ≤ 50 L / m³. 2 • h, the recovery rate of the ultrafiltration unit is ≥90%. The ultrafiltration membrane material must be selected based on its strong resistance to fouling and oxidation. The service life of the ultrafiltration membrane should be more than three years. At any time within three years, the net output should meet the guaranteed value, and the SDI ≤ 3.

[0049] The ultrafiltration unit has interfaces on its feed water and concentrate inlet / outlet mains for connection to the cleaning solution inlet / outlet during cleaning. The ultrafiltration membrane modules are mounted on a frame, which includes all piping and fittings, supports, fasteners, clamps, and other accessories. Piping, flanges, and valves are all made of stainless steel or corrosion-resistant valves. The piping material is adapted to the requirements of the ultrafiltration unit's cleaning media.

[0050] Each ultrafiltration membrane module has sampling points and necessary testing instruments on its water pipes and inlet / outlet pipes. The quantity and location of these instruments effectively monitor, diagnose, and identify system defects. Sampling points are centrally located for easy sampling. The frame is equipped with all pipes and fittings, as well as all supports, fasteners, clamps, and other accessories, and the frame design meets local seismic intensity requirements.

[0051] Ultrafiltration membrane elements can meet the requirements for removing colloidal silica. The operation and backwashing of the ultrafiltration system must meet local / remote programmed control requirements, respectively.

[0052] The chemical cleaning system for the ultrafiltration unit is shared with the chemical cleaning system for the reverse osmosis unit.

[0053] The ultrafiltration unit is equipped with a chemical cleaning interface and valves to connect to the cleaning solution inlet and outlet pipes during cleaning.

[0054] The cleaning system includes a cleaning tank, cleaning pump, cleaning filter, valves, piping, and local flow and pressure gauges. All equipment is assembled on a single chassis, forming a unit. The materials and anti-corrosion coatings of the cleaning system are compatible with the cleaning fluid used.

[0055] The backwash system includes a backwash gas source, a backwash dosing device (including a backwash chlorination device or other dosing devices), valves, pipelines, flexible and reliable sealing joints, and local flow and pressure gauges.

[0056] The backwash system draws water from the ultrafiltration water tank. The backwash system is controlled automatically by a programmed system. The actual dosage of chemicals and the chemical dosing backwash cycle are determined through commissioning.

[0057] The inlet and outlet water headers on the ultrafiltration unit are made of UPVC pipes, and the materials of the external pipes and flanges meet the requirements for corrosion protection.

[0058] The operation and backwashing of the ultrafiltration system can be controlled manually, semi-automatically, and automatically. The operation of the ultrafiltration device is automatically controlled according to the water level in the ultrafiltration water tank.

[0059] A reverse osmosis system includes: a booster pump, a security filter, a high-pressure pump, a reverse osmosis unit, a chemical cleaning system, and a flushing system.

[0060] A complete reverse osmosis system includes a security filter, a high-pressure pump, reverse osmosis membrane modules, supporting instruments, valves, piping systems and main body components, as well as dosing and cleaning equipment.

[0061] The reverse osmosis system operates under automatic control. The system's raw water tank level and water production capacity monitoring instruments are configured to meet the requirements for automatic start-up, shutdown, or system switching.

[0062] A drain valve is installed on the water pipe leading to the security filter.

[0063] The high-pressure pump outlet is equipped with a soft start or slow opening device and a pressure switch to prevent the membrane module from being impacted by high-pressure water and to trigger an alarm and pump stop when the pressure is high.

[0064] A pressure switch is installed at the inlet of the high-pressure pump to trigger an alarm and stop the pump when the pressure is low.

[0065] In reverse osmosis systems, the selection of reverse osmosis membrane elements is based on the characteristics of the water quality, choosing membranes with high permeability, high desalination rate, good chemical stability, and good mechanical strength.

[0066] The design water flux of the reverse osmosis membrane element is selected according to the lower value specified by the membrane element manufacturer. The water flux of the membrane element in this unit is ≤22 L / m³. 2 •h, and select a reasonable arrangement and combination to ensure the normal operation of the membrane element and a reasonable cleaning cycle.

[0067] The selection of chemical cleaning solution is determined based on the quality of the feed water and the characteristics of the selected reverse osmosis membrane module.

[0068] The reverse osmosis unit's main feed water pipe and each section of concentrate pipe, as well as the product water inlet and outlet pipes, are equipped with sufficient interfaces and valves to connect to the cleaning solution inlet and outlet pipes during cleaning.

[0069] A flow control valve must be installed for reverse osmosis concentrate drainage to control the water recovery rate.

[0070] The reverse osmosis unit is equipped with a programmed start-stop device, which can automatically flush after a delay when it is stopped.

[0071] The design of reverse osmosis systems avoids subjecting membrane elements to back pressure.

[0072] Sampling points should be installed on the inlet and product water pipes of the reverse osmosis unit, and their locations and quantities should be specified. The number and location of sampling points can effectively diagnose and determine the operating status of the system.

[0073] The reverse osmosis membrane module is mounted on a frame, which is equipped with all the piping and fittings, as well as all the supports, fasteners, clamps and other accessories.

[0074] The design of the reverse osmosis assembly rack meets the seismic intensity requirements of the plant site and the expansion requirements of the components.

[0075] The flushing system includes flushing pumps, valves, and piping. It is required that the flushing pumps be activated when the high-pressure pump stops.

[0076] The reverse osmosis system piping is designed to avoid dead corners to prevent bacterial growth and is equipped with a flushing system.

[0077] High-pressure pipelines are made of stainless steel that is resistant to corrosion from different media.

[0078] The low-pressure pipeline of the reverse osmosis unit uses UPVC pipes and valves, which are chemical grade and rated at 1.6 MPa.

[0079] The number of monitoring instruments configured in the system meets the needs of safe, stable and reliable operation of the system: the reverse osmosis feed water header is equipped with an online oxidation-reduction potentiometer, pH meter, thermometer, flow meter and conductivity meter; each set of reverse osmosis permeate pipe is equipped with an online flow meter and conductivity meter, and the concentrate discharge pipe is equipped with a flow meter; and it can realize alarm, interlock protection and control functions based on indicators such as outlet conductivity, operating pressure difference, output and so on.

[0080] Flow measurement points: Each reverse osmosis permeate and concentrate discharge unit is equipped with a local flow meter; the cleaning water is equipped with a local flow indicator.

[0081] Pressure measurement sampling points: Local pressure indicators and pressure transmitters are installed at the inlet of each section of the reverse osmosis system and at the concentrate outlet; pressure switches are installed at the inlet and outlet of the reverse osmosis high-pressure pump.

[0082] Liquid level measurement sampling points: Each liquid tank is equipped with a liquid level switch, which can realize the interlocking function of starting and stopping the pump.

[0083] The reverse osmosis inlet header should be equipped with at least an inlet water temperature meter, an inlet water pH meter, and a total inlet water flow meter. Each reverse osmosis unit should be equipped with an inlet pressure transmitter, an inter-stage pressure transmitter, a concentrate pressure transmitter, a product water flow meter, a concentrate flow meter, a product water conductivity meter, a pressure gauge, and other necessary instruments to achieve online monitoring, recording, alarm, and interlock control functions.

[0084] The reverse osmosis system operates automatically based on the water levels in the raw water tank and the reverse osmosis product water tank, as well as the system's water production capacity. Start-up, shutdown, or system switching requires manual intervention by the operator after confirmation.

[0085] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for treating ammonium calcium nitrate wastewater, characterized in that: The system includes a pH adjustment tank, a buffer tank, a heat exchanger, a multi-media filter, a precision filter, a ceramic filter, an ultrafiltration unit, a concentration reverse osmosis unit, a desalination reverse osmosis unit, a concentrate reverse osmosis unit, and a wastewater discharge system. The multi-media filter includes a filter tank containing a layer of fiber ball filter media and is equipped with a liftable compression frame and a support frame structure. The compression frame moves along a vertical guide tube via a magnetic drive mechanism. During filtration, it compresses the fiber balls to form a gradient pore structure. During backwashing, it moves upward to release the fiber balls and triggers the dispersion frame to unfold, assisting in loosening and cleaning the fiber balls. The compression frame is lifted and fitted onto the vertical guide tube within the filter tank, and the support frame is movably suspended at the bottom of the guide tube. The compression frame can limit the movement of the support frame when compressing the fiber balls, and after the compression frame moves upward to release the fiber balls, the support frame vibrates under the action of the magnetic drive mechanism.

2. The ammonium nitrate calcium wastewater treatment device according to claim 1, characterized in that: The compression frame and the support frame are connected by an upper rotating rod and a lower rotating rod to form a dispersion frame. During backwashing, the compression frame moves upward to drive the dispersion frame to unfold and push the fiber balls to disperse.

3. The ammonium calcium nitrate wastewater treatment device according to claim 2, characterized in that: The compression frame is fixed to the guide tube by a pin mechanism. The pin mechanism includes a magnetic end, a movable frame, and a limiting rod. The magnetic force drives the movable frame to move to release the limiting rod from locking the positioning hole, thereby realizing the lifting and lowering control of the compression frame. The positioning hole is set on the side wall of the guide tube.

4. The ammonium calcium nitrate wastewater treatment device according to claim 3, characterized in that: A guide ring is provided in the middle of the compression frame, which is connected to the guide tube. A positioning seat is fixedly installed on the guide ring, and a magnetically controlled pin structure is provided in the positioning seat. The limiting rod is slidably installed in the positioning seat and is connected to the first spring. The bottom of the limiting rod is provided with an inclined groove, and the movable frame is movably installed in the positioning seat and is in contact with the inclined groove.

5. The ammonium nitrate calcium wastewater treatment device according to claim 4, characterized in that: The magnetic drive mechanism includes a waterproof box installed on the top of the filter tank, and the waterproof box is equipped with an electromagnetic positive magnetic seat and a negative magnetic seat. By electromagnetic control, an attractive or repulsive force is applied to the magnetic end of the compression frame, driving the compression frame to move up and down on the guide tube.

6. The ammonium calcium nitrate wastewater treatment device according to claim 5, characterized in that: The bearing frame is movably mounted at the bottom of the guide tube, and a base is provided at the bottom of the guide tube. A lifting rod is connected to the middle of the bearing frame, and the lifting rod is slidably mounted in the base.

7. The ammonium calcium nitrate wastewater treatment device according to claim 6, characterized in that: The lifting rod is connected to a connecting rod that can extend into the guide tube. The top of the connecting rod is provided with a top block, which is connected to a second spring in the guide tube. The top block can be blocked by a limiting rod inserted into the positioning hole.

8. The ammonium calcium nitrate wastewater treatment device according to claim 7, characterized in that: The lifting rod is movable in the base, and a horizontal rotating shaft is provided on the connecting rod. A magnetic plate and a gear are respectively connected to the two ends of the rotating shaft. A vertical rack is provided in the base and meshes with the gear. The magnetic plate can be driven by a magnetic drive mechanism, and the gear can drive the magnetic plate to rotate.

9. The ammonium nitrate calcium wastewater treatment device according to claim 8, characterized in that: The top of the filter tank is equipped with a hanger, and the guide tube is vertically installed at the bottom of the hanger; the waterproof box is installed on the hanger.

10. The ammonium calcium nitrate wastewater treatment device according to claim 9, characterized in that: The filter tank is connected to an upper inlet pipe at the top and a lower inlet pipe at the bottom, with a frame-type four-way pipe connecting the upper and lower inlet pipes. The frame-type four-way pipe has four channels, two of which are connected to the upper and lower inlet pipes, and the other two are water inlets and sewage outlets. A water outlet pipe is connected to the lower inlet pipe, and the inflow and outflow of wastewater and cleaning water are controlled by the channel structure of the frame-type four-way pipe and the valves installed on it.

11. A treatment method for ammonium calcium nitrate wastewater according to claim 10, characterized in that: The method includes the following steps: S1, the ammonium nitrate calcium process condensate is sequentially passed through a pH adjustment tank for pH adjustment, a buffer tank for temporary storage, and a heat exchanger for temperature adjustment; S2, the adjusted wastewater enters a multi-media filter for preliminary filtration to remove suspended solids and colloids; S3, the pre-filtered wastewater is sequentially passed through a precision filter and a ceramic filter for fine filtration; S4, the finely filtered wastewater enters an ultrafiltration unit for ultrafiltration treatment; S5, the ultrafiltration permeate enters a primary reverse osmosis system for primary reverse osmosis treatment, including: temporary storage in a primary reverse osmosis feed tank, pressurization by a primary reverse osmosis booster pump, filtration by a primary reverse osmosis security filter, and further pressurization by a primary reverse osmosis high-pressure pump before entering a primary reverse osmosis system. The first-stage reverse osmosis permeate enters the first-stage reverse osmosis permeate tank after processing by the first-stage reverse osmosis unit; S6, the first-stage reverse osmosis permeate enters the second-stage reverse osmosis system for further processing, including: pressurization by the second-stage reverse osmosis booster pump, filtration by the second-stage reverse osmosis security filter, pressurization by the second-stage reverse osmosis high-pressure pump, and processing by the second-stage reverse osmosis unit, with the permeate entering the reverse osmosis qualified water tank; S7, the water in the qualified water tank is transported to the point of use by the qualified water pump; S8, the first-stage reverse osmosis concentrate enters the concentrate treatment unit, including: temporary storage in the first-stage reverse osmosis concentrate tank, pressurization by the concentrate reverse osmosis high-pressure pump, and processing by the concentrate reverse osmosis unit, with the concentrate being recycled for the production of calcium ammonium nitrate by the reverse osmosis concentrate recovery pump.

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