A heterogeneous nucleation circulating crystallization granulation fluid bed and system thereof

Abstract

This invention relates to a heterogeneous nucleation circulating crystallization granulation fluidized bed and its system. The fluidized bed includes a water collection zone, a circulating crystallization zone, a filtration zone, and a mineralization zone. The circulating crystallization zone includes an inner cylinder, an outer cylinder outside the inner cylinder, an outer cylinder bottom at the bottom of the outer cylinder, and a throat and a flow guiding component at the outer cylinder bottom. The inlet of the throat is in the filtration zone, and the outlet is in the circulating crystallization zone. The circulating crystallization zone and the water collection zone are connected. The filtration zone includes a filter cylinder, a filter cylinder bottom at the bottom of the filter cylinder, a main water supply pipe for the filtration zone inside the filter cylinder, and a filter component. The mineralization zone includes a mineralization cylinder, a water distributor plate inside the mineralization cylinder, a water distributor on the water distributor plate, a flow guiding plate below the water distributor plate, a lower water inlet below the flow guiding plate, an air inlet communicating with the lower part of the mineralization cylinder, and a water collection plate at the upper part of the mineralization cylinder. The flow guiding component is connected to the upper part of the mineralization cylinder through a crystallization particle conveying device. This system can be used to adjust the hardness of seawater desalination product.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to a heterogeneous nucleation circulating crystallization granulation fluidized bed and its system. Background Technology

[0002] The treatment of circulating wastewater from thermal power plants and the resulting crystal particles after the adoption of heterogeneous nucleation crystallization granulation technology has become a real problem that needs to be solved. Currently, the treatment of circulating wastewater usually involves filtration devices, with security filters being a common example. However, after a period of use, these security filters typically require shutdown to replace the filter element, making it impossible to achieve filtration without shutting down the system.

[0003] Meanwhile, in membrane-based seawater desalination projects, the reverse osmosis membrane technology used intercepts most of the ions in seawater, resulting in low hardness of the desalinated water. When used as drinking water, this water lacks essential minerals such as calcium ions. Therefore, desalinated water requires post-mineralization treatment to increase its hardness before it can be used as drinking water. Currently, the main technology for mineralizing desalinated water is to add calcium-rich chemical agents, such as slaked lime (calcium hydroxide Ca(OH)2), magnesium oxide (calcium carbonate MgOCaCO3), and calcium chloride (CaCl2). However, the artificial addition of these chemical agents can easily cause secondary pollution to the desalinated water due to other components within them.

[0004] Therefore, there is an urgent need for a novel coupling technology of heterogeneous nucleation crystallization, crystallization granulation and mineralization to achieve the adjustment of the hardness of seawater desalination products without the need for artificial addition of chemical agents, and to achieve efficient treatment of circulating wastewater. Summary of the Invention

[0005] The purpose of this invention is to solve the problem of difficult-to-treat crystal particles generated after the use of heterogeneous nucleation crystallization granulation technology in the circulating wastewater and circulating wastewater system of thermal power plants, as well as the problem that the addition of chemical agents for hardness adjustment of seawater desalination products can easily cause secondary pollution to seawater desalination products due to other components contained in the chemical agents. The invention provides a heterogeneous nucleation circulating crystallization granulation fluidized bed and its system.

[0006] To achieve the above objectives, the first aspect of the present invention provides a heterogeneous nucleation circulating crystallization granulation fluidized bed, which includes a water collection zone, a circulating crystallization zone, a filtration zone and a mineralization zone forming an integral structure.

[0007] The circulating crystallization zone includes an inner cylinder, an outer cylinder disposed outside the inner cylinder, an outer cylinder bottom disposed at the bottom of the outer cylinder, and a throat and a flow guiding component disposed at the center of the outer cylinder bottom. The inlet of the throat is disposed at the top of the filtration zone, and the outlet is disposed at the bottom of the circulating crystallization zone. The circulating crystallization zone is connected to the water collection zone.

[0008] The filtration zone includes a filter cylinder, a filter cylinder bottom disposed at the bottom of the filter cylinder, a filtration zone water production main pipe disposed inside the filter cylinder, and at least two filter components. The filter components are used to filter the circulating wastewater entering the zone, and the filtration zone water production main pipe is used to transport the circulating wastewater filtered by the filter components to the circulating crystallization zone through the throat pipe.

[0009] The mineralization zone includes a mineralization cylinder, a water distributor plate disposed inside the mineralization cylinder and dividing the cylinder into upper and lower parts, several water distributors disposed on the water distributor plate, the nozzles of the water distributors being located at the upper part of the mineralization cylinder, the water inlet head being located at the lower part of the mineralization cylinder, and several air inlets being provided on the side of the water inlet head, a guide plate disposed below the water distributor plate, a lower water inlet disposed below the guide plate, an air inlet communicating with the lower part of the mineralization cylinder, and a water collection plate disposed at the upper part of the mineralization cylinder for guiding the mineralized water flow to the outside; the upper part of the mineralization cylinder and the guide component are connected by a crystallization particle conveying device.

[0010] Optionally, the nozzle has 4-8 spray surfaces on its circumferential side, and each spray surface has 5-9 nozzles.

[0011] Optionally, the nozzle located at the center of each spray surface sprays water in a horizontal direction, while the other nozzles spray water at an angle of 15-25° outward from the center nozzle.

[0012] Optionally, a crystallization granulation particle monitoring device is provided on the upper part of the mineralization cylinder to monitor the height of the crystallization granulation particle layer on the water distributor plate.

[0013] Optionally, the height of the crystalline granulation layer ranges from 500 to 900 mm.

[0014] Optionally, the water collection tray has a U-shaped basin structure.

[0015] Optionally, the crystallizing particle conveying device includes an upper particle discharge ring, a lower particle discharge ring, and a plurality of connecting pipes connecting the upper particle discharge ring and the lower particle discharge ring. A crystallizing particle discharge control valve is provided on the connecting pipe. A plurality of guide pipes are provided at intervals on the inner sides of the upper particle discharge ring and the lower particle discharge ring. The guide pipe of the upper particle discharge ring is connected to the bottom of the guide component of the circulating crystallization zone, and the guide pipe of the lower particle discharge ring is connected to the upper part of the mineralization cylinder.

[0016] Optionally, the flow guiding component is disposed at the bottom center of the outer cylinder bottom, and the flow guiding component has a smooth W-shaped cross-section with a through hole in the center for the throat tube to pass through.

[0017] Optionally, a lower partition and an upper partition are sequentially arranged above the bottom of the filter cylinder. The outlet of the main water production pipe of the filtration zone is connected to the inlet of the throat pipe. The inlet extends through the upper partition and the lower partition to the water production chamber between the lower partition and the bottom of the filter cylinder. One end of the filter shell of the filter component is located above the upper partition, and the other end passes through the upper partition and is placed in the water inlet jacket between the upper partition and the lower partition. A water production pipe is arranged in the middle of the interior of the filter shell. One end of the water production pipe passes through the filter shell and the lower partition and extends into the water production chamber. A plurality of filter discs are arranged on the outer surface of the water production pipe above the upper partition. A pressing component is arranged on the top of the filter shell to press the filter discs, so that filter holes are formed between adjacent filter discs. A plurality of opposing strip holes are arranged along the axial direction of the water production pipe. The upper water inlet pipe located outside the filter cylinder is connected to the interior of the filter shell in the water inlet jacket.

[0018] Optionally, the filter component further includes a backwash discharge three-way valve and an upper drain pipe;

[0019] The backwash discharge three-way valve is installed on the upper water inlet pipe, the upper sewage pipe is connected to the backwash discharge three-way valve, and the filter water production pipe is provided with several tangential strip holes along the axial direction.

[0020] Optionally, the filter water production pipe is a hollow cylinder, and the filter discs are filter discs with micron-level triangular grooves cast on both sides.

[0021] Optionally, the water collection area includes a water collection cavity, a guide ring disposed in the water collection cavity, and an upper water outlet communicating with the water collection cavity.

[0022] A second aspect of the present invention provides a heterogeneous nucleation circulating crystallization granulation fluidized bed system, the fluidized bed system comprising a hydrocyclone and the fluidized bed described above, wherein the seed end of the hydrocyclone is connected to the water collection zone, and the mineralized water end is connected to the water outlet end of the water collection plate.

[0023] According to the above technical solution, based on the heterogeneous nucleation circulating crystallization granulation fluidized bed and its system, the water entering the circulating crystallization zone can be purified by treating the power plant circulating wastewater (with high suspended solids (SS) content) through the filtration zone. Furthermore, under the action of seed crystals, calcium ions in the purified circulating wastewater can be removed through the circulating crystallization zone to achieve crystallization granulation. Then, the crystallized granules in the circulating crystallization zone are transferred to the mineralization zone through the crystallization particle conveying device, where they react under the action of carbon dioxide to produce calcium bicarbonate. The dissolved calcium ions are used to adjust the hardness of the seawater desalination reverse osmosis permeate. Finally, the crystal seed crystals in the mineralized reverse osmosis permeate can be recovered through the water collection zone to the circulating crystallization zone for circulating crystallization granulation by the hydrocyclone. By coupling crystallization granulation and mineralization technologies, the hardness of seawater desalination product can be adjusted without the need for artificial chemical addition, and efficient treatment of circulating wastewater can be achieved. It also absorbs a large amount of carbon dioxide gas, and by removing calcium ions from the cleaned circulating wastewater, it can effectively improve the tendency of calcium salt scaling in subsequent membrane treatment processes.

[0024] Specifically, the reaction equation for the mineralization technology is as follows:

[0025] CaCO3 + CO2 + H2O = Ca 2+ +2HCO3 -

[0026] Meanwhile, by setting a guide plate below the water distributor plate, and a lower water inlet below the guide plate, the bottom water intake can be made stable and uniform, avoiding the occurrence of water turbulence, thereby improving the mineralization effect of seawater desalination product.

[0027] The nozzle has 4-8 spray surfaces arranged around its circumference, each with 5-9 nozzles. The central nozzle on each surface sprays water horizontally, while the other nozzles spray water at a 15-25° angle outwards from the central nozzle. This enhances the contact between the desalination product and the crystallized particles, thereby improving the mineralization effect of the desalination product. Furthermore, a crystallized particle monitoring device is installed at the top of the cylinder to monitor the height of the crystallized particle layer on the water distributor plate. A crystallized particle layer height of 500-900mm further enhances the contact between the desalination product and the crystallized particles.

[0028] The U-shaped water collection tray is used to guide the mineralized reverse osmosis permeate, which can minimize the disturbance of the water flow from the side wall of the conventional permeate, making the water flow in the mineralization zone more stable, thereby improving the mineralization effect of the seawater desalination permeate.

[0029] By setting the filter components, not only can the circulating sewage be effectively filtered based on the filter discs with micron-level triangular grooves cast on both sides, but the filter discs of the other filter component can also be cleaned while one filter component is used to filter the circulating sewage. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a heterogeneous nucleation, cyclic crystallization, and granulation fluidized bed;

[0031] Figure 2 This is a schematic diagram of the structure of a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed system in a specific embodiment;

[0032] Figure 3 This is a schematic diagram of the water distributor of a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed;

[0033] Figure 4 This is a nozzle layout diagram of the nozzles for a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed.

[0034] Figure 5 This is a schematic cross-sectional view of the guide plate structure of a heterogeneous nucleation cyclic crystallization granulation fluidized bed;

[0035] Figure 6 This is a three-dimensional structural diagram of the guide plate of a heterogeneous nucleation and cyclic crystallization granulation fluidized bed;

[0036] Figure 7 This is a schematic diagram of the water collection tray of a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed;

[0037] Figure 8 This is a schematic diagram of the crystallization particle conveying device in a heterogeneous nucleation circulating crystallization granulation fluidized bed.

[0038] Figure 9 This is a schematic diagram of the flow guiding component of a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed;

[0039] Figure 10 This is a schematic diagram of the filtration zone of a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed.

[0040] Figure 11 This is a schematic diagram of the structure of multiple filtration components in a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed;

[0041] Figure 12 This is a schematic diagram of the structure of a single filter component in a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed;

[0042] Figure 13 This is a partial structural diagram of the filter water production pipe of a heterogeneous nucleation circulating crystallization granulation fluidized bed;

[0043] Figure 14 This is a schematic diagram of the cross-sectional structure of the filter water production pipe of a heterogeneous nucleation circulating crystallization granulation fluidized bed;

[0044] Figure 15 This is a top view schematic diagram of the filter water production pipe of a heterogeneous nucleation circulating crystallization granulation fluidized bed;

[0045] Figure 16 This is a schematic diagram of the filter pores formed by adjacent filter stacks in a heterogeneous nucleation, circulating crystallization, and granulation fluidized bed.

[0046] Explanation of reference numerals in the attached figures

[0047] 1. Water collection area; 11. Water collection chamber; 12. Flow guide ring; 13. Upper outlet; 2. Circulation crystallization zone; 21. Inner cylinder; 22. Outer cylinder; 23. Bottom of outer cylinder; 24. Throat; 25. Flow guide component; 3. Filtration zone; 31. Filter cylinder; 32. Bottom of filter cylinder; 33. Lower baffle; 34. Upper baffle; 35. Main water supply pipe for filtration zone; 36. Filtration component; 361. Filter shell; 362. Filter water supply pipe; 3621. Opposing strip holes; 3622. Tangential strip holes; 363. Filter discs; 3631. Filter holes; 364. Pressing component; 365. Upper inlet pipe; 366. Backwash discharge three-way valve; 36 7. Upper drain pipe; 4. Mineralization zone; 41. Mineralization cylinder; 42. Water distributor; 421. Sprinkler head; 422. Nozzle; 423. Water inlet head; 424. Air inlet; 43. Water distributor plate; 44. Water collection plate; 45. Lower outlet; 46. Air inlet; 47. Lower inlet; 48. Lower manhole; 49. Upper manhole; 50. Guide plate; 5. Support leg; 6. Crystallized particle conveying device; 61. Upper particle discharge ring; 62. Connecting pipe; 63. Lower particle discharge ring; 64. Crystallized particle discharge control valve; 7. Hydrocyclone; 71. Hydrocyclone outlet; 8. Conveying pump; 91. First valve; 92. Second valve; 93. Third valve. Detailed Implementation

[0048] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0049] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of indicated technical features. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean a non-exclusive inclusion, the possibility of the presence or addition of one or more other features, units, components, and / or combinations thereof.

[0050] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] The first aspect of this invention provides a heterogeneous nucleation circulating crystallization granulation fluidized bed, such as... Figure 1 As shown in 3-16, the heterogeneous nucleation circulating crystallization granulation fluidized bed includes a water collection zone 1, a circulating crystallization zone 2, a filtration zone 3, and a mineralization zone 4, which constitute an integrated structure.

[0052] The circulating crystallization zone 2 includes an inner cylinder 21, an outer cylinder 22 disposed outside the inner cylinder 21, an outer cylinder bottom 23 disposed at the bottom of the outer cylinder 22, and a throat 24 and a flow guiding component 25 disposed at the center of the outer cylinder bottom 23. The inlet of the throat 24 is disposed at the top of the filtration zone 3, and the outlet is disposed at the bottom of the circulating crystallization zone 2. The circulating crystallization zone 2 is connected to the water collection zone 1.

[0053] The filtration zone 3 includes a filter cylinder 31, a filter cylinder bottom 32 disposed at the bottom of the filter cylinder 31, a filtration zone water production main pipe 35 disposed inside the filter cylinder 31, and at least two filter components 36. The filter components 36 are used to filter the circulating wastewater entering the zone. The filtration zone water production main pipe 35 is used to transport the circulating wastewater filtered by the filter components 36 to the circulating crystallization zone 2 through the throat pipe 24.

[0054] The mineralization zone 4 includes a mineralization cylinder 41, a water distributor plate 43 disposed inside the mineralization cylinder 41 and dividing the mineralization cylinder 41 into upper and lower parts, several water distributors 42 disposed on the water distributor plate 43, the nozzles 421 of the water distributors 42 being located at the upper part of the mineralization cylinder 41, the water inlet head 423 being located at the lower part of the mineralization cylinder 41, and several air inlets 424 being provided on the side of the water inlet head 423, a guide plate 50 disposed below the water distributor plate 43, a lower water inlet 47 disposed below the guide plate 50, an air inlet 46 communicating with the lower part of the mineralization cylinder 41, and a water collection plate 44 disposed at the upper part of the mineralization cylinder 41 for guiding the mineralized water flow to the outside; the upper part of the mineralization cylinder 41 and the guide component 25 are connected by a crystallization particle conveying device 6.

[0055] The guide plate 50, located below the water distributor plate 43, has a lower water inlet 47 below it. This design ensures stable and uniform bottom water intake, preventing turbulence and improving the mineralization effect of the desalination product. Specifically, as... Figure 5 and 6 As shown, the desalinated seawater to be mineralized enters the lower part of the mineralization cylinder 41 through the lower inlet 47 and achieves stable and uniform water intake under the guiding action of the guide plate 50. Furthermore, under the action of the water distributor 42, carbon dioxide and water can enter the nozzle 421 through the air inlet 424 and water inlet 423 located at the lower part of the mineralization cylinder 41, respectively, thereby achieving mineralization of the desalinated seawater in the upper part of the mineralization cylinder 41.

[0056] The mineralization cylinder 41 is provided with support legs 5 on the outer side of its bottom. The upper and lower parts of the mineralization cylinder 41 are respectively provided with an upper manhole 49 and a lower manhole 48 for maintenance. In the initial state, both the upper manhole 49 and the lower manhole 48 are in a sealed state.

[0057] According to the above technical solution, based on the heterogeneous nucleation circulating crystallization granulation fluidized bed and its system, the water entering the circulating crystallization zone can be purified by treating the power plant circulating wastewater (with high suspended solids (SS) content) through the filtration zone. Furthermore, under the action of seed crystals, calcium ions in the purified circulating wastewater can be removed through the circulating crystallization zone to achieve crystallization granulation. Then, the crystallized granules in the circulating crystallization zone are transferred to the mineralization zone through the crystallization particle conveying device, where they react under the action of carbon dioxide to produce calcium bicarbonate. The dissolved calcium ions are used to adjust the hardness of the seawater desalination reverse osmosis permeate. Finally, the crystal seed crystals in the mineralized reverse osmosis permeate can be recovered through the water collection zone to the circulating crystallization zone for circulating crystallization granulation by the hydrocyclone. By coupling crystallization granulation and mineralization technologies, the hardness of seawater desalination product can be adjusted without the need for artificial chemical addition, and efficient treatment of circulating wastewater can be achieved. It also absorbs a large amount of carbon dioxide gas, and by removing calcium ions from the cleaned circulating wastewater, it can effectively improve the tendency of calcium salt scaling in subsequent membrane treatment processes.

[0058] In the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention, preferably, the water collection zone 1 includes a water collection cavity 11, a guide ring 12 disposed within the water collection cavity 11, and an upper outlet 13 communicating with the water collection cavity 11. For example... Figure 1As shown, by setting up the water collection zone 1 and the circulating crystallization zone 2, in practical applications, a certain amount of seed crystals (typically with a particle size of no more than 0.09 mm) are pre-added to the circulating crystallization zone 2. Then, the circulating wastewater from the main water supply pipe 35 of the filtration zone enters the circulating crystallization zone 2 through the throat pipe 24. Under the guidance of the guide ring 12 and the smooth W-shaped guide component 25 located at the center of the bottom of the outer cylinder bottom 23, the circulating wastewater carries the seed crystals and undergoes circulating fluidization to form crystallized granules. As the running time continues, the crystallized granules continuously grow. Finally, according to engineering experience, when the particle size of the crystallized granules grows to 2-3 mm, under the action of water pressure, the crystallization particle discharge control valve 64 of the crystallization particle conveying device 6 can periodically discharge them into the upper part of the mineralization cylinder 41. Specifically, the implementation process based on the water collection zone 1 and the circulating crystallization zone 2 is described in patent publication number CN111547927A, and will not be repeated here.

[0059] In one specific implementation, such as Figure 1 , 8 As shown in Figure 9, the crystallizing particle conveying device 6 includes an upper particle discharge ring 61, a lower particle discharge ring 63, and a plurality of connecting pipes 62 connecting the upper particle discharge ring 61 and the lower particle discharge ring 63. A crystallizing particle discharge control valve 64 is provided on the connecting pipe 62. A plurality of guide pipes are provided at intervals on the inner side of the upper particle discharge ring 61 and the lower particle discharge ring 63. The guide pipe of the upper particle discharge ring 61 is connected to the bottom of the guide component 25 of the circulating crystallization zone 2, and the guide pipe of the lower particle discharge ring 63 is connected to the upper part of the mineralization cylinder 41.

[0060] In the heterogeneous nucleation cyclic crystallization granulation fluidized bed described in this invention, preferably, as follows: Figure 10-16As shown, a lower partition 33 and an upper partition 34 are sequentially arranged above the bottom 32 of the filter cylinder. The outlet of the main water production pipe 35 of the filtration zone is connected to the inlet of the throat pipe 24. The inlet extends sequentially through the upper partition 34 and the lower partition 33 into the water production chamber between the lower partition 33 and the bottom 32 of the filter cylinder. One end of the filter housing 361 of the filter component 36 is located above the upper partition 34, and the other end passes through the upper partition 34 and is placed in the water inlet interlayer between the upper partition 34 and the lower partition 33. A water production pipe 362 is arranged in the middle of the interior of the filter housing 361. The filter tube 362 passes sequentially through the filter housing 361 and the lower partition 33 and extends into the filter water production chamber. A plurality of filter discs 363 are arranged on the outer surface of the filter water production pipe 362 above the upper partition 34. A pressing component 364 is disposed on the top of the filter housing 361 to press the filter discs 363, so that filter holes 3631 are formed between adjacent filter discs 363. The filter water production pipe 362 has a plurality of opposing strip-shaped holes 3621 arranged axially. The upper inlet pipe 365, located outside the filter cylinder 31, communicates with the interior of the filter housing 361 within the inlet jacket, thereby achieving effective filtration of circulating wastewater. Specifically, the pressing component 364 is a component with an internal check spring, which can be opened during reverse water intake and pressed inward under the elastic action of the check spring during forward water intake.

[0061] In a further preferred embodiment, the filter component 36 further includes a backwash discharge three-way valve 366 and an upper drain pipe 367;

[0062] The backwash discharge three-way valve 366 is installed on the upper water inlet pipe 365, and the upper sewage pipe 367 is connected to the backwash discharge three-way valve 366. The filter water production pipe 362 is provided with a number of tangential strip holes 3622 along the axial direction, so as to effectively filter the circulating sewage while realizing the backwashing of the filter discs 363.

[0063] In another further preferred embodiment, the filter water production pipe 362 is a hollow cylinder, and the filter stack 363 is a filter stack with micron-level triangular grooves cast on both sides, thereby better filtering the circulating sewage and realizing the backwashing of the filter stack 363.

[0064] In practical applications, the filter operates under the following conditions:

[0065] Driven by the booster pump, the circulating wastewater enters the three filter components 36. Specifically, with the backwash discharge three-way valve 366 inlet channel open (backwash discharge channel closed), the circulating wastewater enters each filter housing 361 through the upper inlet pipe 365. Then, the water entering the filter housing 361 flows through the filter holes 3631 (diamond-shaped filter channels) between several adjacent filter plates with micron-level triangular grooves cast on both sides, and enters the filter product water pipe 362 through several opposing strip holes 3621 arranged axially. After being filtered by several filter plates 363, the circulating wastewater enters the filter product water chamber under the action of the filter product water pipe 362, and is transported to the circulating crystallization zone 2 for fluidized granulation through the filter zone product water main pipe 35 and the throat pipe 24.

[0066] Cleaning without shutting down the machine:

[0067] As the working water volume increases, the impurities intercepted by the filter disc 363 gradually increase. As the impurities accumulate, the internal and external pressure difference of the filter disc 363 increases. When the pressure difference between the influent side and the product water side of the filter disc 363 reaches a certain value or the set filtration time is reached, the backwash discharge three-way valve 366 of the designated filter component 36 needs to be opened to discharge the sewage. Specifically, two of the filter elements 36 are in the filtration state, and one of the filter elements 36 is in the backwash state. The backwash discharge three-way valve 366 of the filter element 36 in the backwash state is open (the inlet channel is closed). The circulating wastewater enters the respective filter housings 361 through the upper inlet pipes 365 of the two filter elements 36 in the filtration state. Then, the water entering the filter housings 361 flows through the filter holes 3631 formed between several adjacent filter plates with micron-level triangular grooves cast on both sides, and enters the filter water production pipe 362 through several opposing strip-shaped holes 3621 arranged axially. Finally, the circulating wastewater, after being filtered by several filter plates 363, enters the filter water production chamber under the action of the filter water production pipe 362. One stream flows through the main water supply pipe 35 and the throat pipe 24 of the filtration zone to the circulating crystallization zone 2 for fluidized granulation. The other stream enters the filter water supply pipe 362 of the filter component 36, which is in a backwashing state. At this time, the clamping component 364 is lifted by water pressure, and the small pores between all the filter discs 363 are loosened. Water is sprayed tangentially through the tangential strip holes 3622 of the filter water supply pipe 362, causing the filter discs 363 to rotate. Under the action of the water flow and the separation force of the rotation of the filter discs 363, the dirt trapped on the filter discs 363 is washed away, forming backwash wastewater. Subsequently, the backwash wastewater enters the upper drain pipe 367 of the backwash discharge three-way valve 366 through the gap between the filter discs 363 and the filter shell 361, and is discharged from the fluidized bed equipment. During backwashing, the filter pores between the filter discs 363 are fully opened, and with the centrifugal jet action, a very good cleaning effect is achieved. When the backwash discharge three-way valve 366 returns to the open state (backwash discharge channel closed), the clamping component 364 on the filter product water pipe 362 presses the filter discs 363 back into place, restoring the filter discs 363 to the filtration state. Within the filtration zone, each filter component 36 is backwashed sequentially. The three filter components 36 automatically switch between filtration and backwashing states to ensure continuous water output.

[0068] In the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention, preferably, the nozzle 421 has 4-8 spray surfaces on its circumferential side, and each spray surface has 5-9 nozzles 422. As an example, the number of spray surfaces can be 4, 5, 6, 7, or 8, preferably 6. The number of nozzles 422 can be 5, 6, 7, 8, or 9, preferably 7. By providing multiple spray surfaces on the circumferential side of the nozzle 421 and multiple nozzles 422 on these spray surfaces, the contact between the seawater desalination product and the crystallization granulation particles can be enhanced, thereby improving the mineralization effect on the seawater desalination product.

[0069] In a further preferred embodiment, the central nozzle 422 on each spray surface sprays water horizontally, while the other nozzles 422 spray water at an outward angle of 15-25° around the central nozzle 422. As an example, the outward angle of the other nozzles besides the central nozzle 422 can be 15°, 16°, 17°, 18°, 19°, 20°, 21°, 22°, 23°, 24°, and 25°, preferably 20°. Figure 3-4 As shown, by spraying water in a horizontal direction with the central nozzle 422 and spraying water at a set angle with the other nozzles 422 tilted outward around the central nozzle 422, the contact between the seawater desalination product and the crystallizing particles can be further enhanced, thereby improving the mineralization effect of the seawater desalination product.

[0070] In the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention, preferably, a crystallization granulation particle monitoring device is provided on the upper part of the cylinder 41 to monitor the height of the crystallization granulation particle layer on the water distributor plate 43. By keeping the height of the crystallization granulation particle layer on the water distributor plate 43 within a set range, for example, within a height range of 500-900 mm, preferably within a height range of 600-800 mm, it can be further used in conjunction with the water distributor 42 to enhance the contact between the seawater desalination product and the crystallization granulation particles, thereby improving the mineralization effect and rate of the seawater desalination product.

[0071] In the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention, preferably, the water collection plate 44 has a U-shaped basin structure, used to guide and discharge the mineralized reverse osmosis permeate, which can maximize the avoidance of water flow disturbance from the conventional permeate discharged from the side wall, making the water flow in the mineralization zone more stable, thereby improving the mineralization effect on seawater desalination permeate. Specifically, as Figure 7 As shown, the water collection tray 44 is connected to the upper inner wall of the mineralization cylinder 41 through 6 obliquely pulled rectangular connecting plates, and the mineralized water is diverted to the outside through the lower water outlet 45 connected to its bottom.

[0072] A second aspect of this invention provides a heterogeneous nucleation circulating crystallization granulation fluidized bed system. This fluidized bed system includes a hydrocyclone 7 and the aforementioned fluidized bed. The seed crystal end of the hydrocyclone 7 is connected to the water collection zone 1, and the mineralized water end is connected to the outlet end of the water collection pan 44. Specifically, water flowing from the lower outlet 45 of the water collection pan 44 can be diverted to the outside and / or flow to the hydrocyclone 7, thereby allowing the seed crystals in the mineralized reverse osmosis permeate to be recovered through the water collection zone 1 and returned to the circulating crystallization zone 2 for circulating crystallization granulation. Whether the water flows to the outside or to the hydrocyclone 7 is determined according to actual needs. Specifically, for example... Figure 2 As shown, in Mode a: When it is necessary to recover the crystal seeds, open the first valve 91 and the second valve 92, close the third valve 93, and start the transfer pump 8 to transport the mineralized seawater desalination product to the hydrocyclone 7. Under the action of the hydrocyclone 7, the purified water flows out from the hydrocyclone outlet 71, and the separated crystal seeds enter the circulating crystallization zone 2 for recycling under the action of gravity through the water collection zone 1. In Mode b: When it is not necessary to recover the crystal seeds, open the third valve 93 and close the first valve 91 and the second valve 92, allowing the mineralized seawater desalination product to flow out directly. In Mode c: Of course, some crystal seeds can also be recovered. In this case, open the first valve 91, the second valve 92, and the third valve 93 and start the transfer pump 8. However, in practical applications, Modes a and b are commonly used.

[0073] The present invention will be described in detail below through embodiments, but the scope of protection of the present invention is not limited thereto.

[0074] Example 1

[0075] Adopting such Figure 1 and 3 The heterogeneous nucleation circulating crystallization granulation fluidized bed shown in -16 is used for mineralization of seawater desalination products. Specifically, the heterogeneous nucleation circulating crystallization granulation fluidized bed includes a water collection zone 1, a circulating crystallization zone 2, a filtration zone 3, and a mineralization zone 4, which form an integrated structure.

[0076] The circulating crystallization zone 2 includes an inner cylinder 21, an outer cylinder 22 disposed outside the inner cylinder 21, an outer cylinder bottom 23 disposed at the bottom of the outer cylinder 22, and a throat 24 and a flow guiding component 25 disposed at the center of the outer cylinder bottom 23. The inlet of the throat 24 is disposed at the top of the filtration zone 3, and the outlet is disposed at the bottom of the circulating crystallization zone 2. The circulating crystallization zone 2 is connected to the water collection zone 1.

[0077] The filtration zone 3 includes a filter cylinder 31, a filter cylinder bottom 32 disposed at the bottom of the filter cylinder 31, a filtration zone water production main pipe 35 disposed inside the filter cylinder 31, and at least two filter components 36. The filter components 36 are used to filter the circulating wastewater entering the zone. The filtration zone water production main pipe 35 is used to transport the circulating wastewater filtered by the filter components 36 to the circulating crystallization zone 2 through the throat pipe 24.

[0078] The mineralization zone 4 includes a mineralization cylinder 41, a water distributor plate 43 disposed inside the mineralization cylinder 41 and dividing the mineralization cylinder 41 into upper and lower parts, several water distributors 42 disposed on the water distributor plate 43, the nozzles 421 of the water distributors 42 being located at the upper part of the mineralization cylinder 41, the water inlet head 423 being located at the lower part of the mineralization cylinder 41, and several air inlet holes 424 being provided on the side of the water inlet head 423, a guide plate 50 disposed below the water distributor plate 43, a lower water inlet 47 disposed below the guide plate 50, an air inlet 46 communicating with the lower part of the mineralization cylinder 41, and a water collection plate 44 disposed at the upper part of the mineralization cylinder 41 for guiding the mineralized water flow to the outside; the upper part of the mineralization cylinder 41 is connected to the guide component 25 through a crystallization particle conveying device 6.

[0079] The water collection tray 44 has a U-shaped basin structure and is used to guide the mineralized reverse osmosis permeate through the lower outlet 45 for discharge. The crystallization particle conveying device 6 includes an upper particle discharge ring 61, a lower particle discharge ring 63, and several connecting pipes 62 connecting the upper particle discharge ring 61 and the lower particle discharge ring 63. A crystallization particle discharge control valve 64 is provided on the connecting pipe 62. Several guide pipes are provided at intervals on the inner sides of the upper particle discharge ring 61 and the lower particle discharge ring 63. The guide pipe of the upper particle discharge ring 61 is connected to the bottom of the guide component 25 of the circulating crystallization zone 2, and the guide pipe of the lower particle discharge ring 63 is connected to the upper part of the mineralization cylinder 41.

[0080] The flow guiding component 25 is located at the bottom center of the outer cylinder bottom 23. The cross-section of the flow guiding component 25 is smooth W-shaped and has a through hole in the center for the throat tube 24 to pass through.

[0081] The water collection area 1 includes a water collection cavity 11, a guide ring 12 disposed in the water collection cavity 11, and an upper water outlet 13 communicating with the water collection cavity 11.

[0082] In practical applications, the circulating wastewater, driven by the booster pump, enters the filter cylinder 31. Then, under the action of the filter element 36, the circulating wastewater is filtered before entering the circulating crystallization zone 2 through the filter zone's main water pipe 35 and throat pipe 24 for fluidized granulation. When the particle size of the crystallized particles at the bottom of the guide element 25 reaches 2-3 mm, under water pressure, the crystallization particle discharge control valve 64 of the crystallization particle conveying device 6 can periodically discharge them into the mineralization cylinder. At the upper part of 41, when the crystallized granulation particle layer on the water distributor plate 43 reaches a certain height, the desalination water is introduced into the lower part of the mineralization cylinder 41 through the lower inlet 47 and guided by the guide plate 50. Carbon dioxide is introduced into the lower part of the mineralization cylinder 41 through the air inlet 46. The water flows to the nozzle 421 through the water inlet head 423, and the carbon dioxide enters the nozzle 421 through the air inlet 424. Finally, the desalination water is mineralized in the upper part of the mineralization cylinder 41 and then guided to the outside through the water collection plate 44.

[0083] The heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention couples crystallization and mineralization technologies, enabling the mineralization of seawater desalination product water without the need for artificial chemical addition. It also achieves efficient treatment of circulating wastewater and absorbs a large amount of carbon dioxide. Furthermore, by removing calcium ions from the cleaned circulating wastewater, it can effectively improve the tendency of calcium salt scaling in subsequent membrane treatment processes.

[0084] Example 2

[0085] Referring to Embodiment 1, the difference is that the nozzle 421 has 6 spray surfaces around its circumference, and each spray surface has 7 nozzles 422. The central nozzle 422 on each spray surface sprays water horizontally, while the other nozzles 422 spray water at a 20° angle outward from the central nozzle 422. A crystallization granulation particle monitoring device is provided on the upper part of the cylinder 41 to monitor the height of the crystallization granulation particle layer on the water distributor plate 43. The height of the crystallization granulation particle layer ranges from 600 to 800 mm.

[0086] Compared with the scheme in Example 1, the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention can further enhance the contact between seawater desalination product and crystallization granulation particles, thereby improving the mineralization effect on seawater desalination product.

[0087] Example 3

[0088] Referring to Embodiment 2, the difference is that a lower partition 33 and an upper partition 34 are sequentially arranged above the bottom 32 of the filter cylinder. The outlet of the main water production pipe 35 of the filtration zone is connected to the inlet of the throat pipe 24. The inlet extends sequentially through the upper partition 34 and the lower partition 33 into the water production chamber between the lower partition 33 and the bottom 32 of the filter cylinder. One end of the filter shell 361 of the filter component 36 is located above the upper partition 34, and the other end passes through the upper partition 34 and is placed in the water inlet interlayer between the upper partition 34 and the lower partition 33. A water production pipe 36 is arranged in the middle of the interior of the filter shell 361. 2. One end of the filter water production pipe 362 passes through the filter shell 361 and the lower partition 33 in sequence and extends into the filter water production chamber. The outer surface of the filter water production pipe 362 above the upper partition 34 is provided with a plurality of filter plates 363. A pressing component 364 is provided on the top of the filter shell 361 to press the filter plates 363, so that filter holes 3631 are formed between adjacent filter plates 363. The filter water production pipe 362 is provided with a plurality of opposing strip holes 3621 along the axial direction. The upper water inlet pipe 365 located outside the filter cylinder 31 communicates with the interior of the filter shell 361 in the water inlet jacket.

[0089] The filter component 36 further includes a backwash discharge three-way valve 366 and an upper drain pipe 367. The backwash discharge three-way valve 366 is installed on the upper water inlet pipe 365, and the upper drain pipe 367 is connected to the backwash discharge three-way valve 366. The filter water production pipe 362 has several tangential strip holes 3622 arranged along the axial direction. The filter water production pipe 362 is a hollow cylinder, and the filter discs 363 are filter discs with micron-level triangular grooves cast on both sides.

[0090] Compared with the scheme in Example 2, the heterogeneous nucleation circulating crystallization granulation fluidized bed described in this invention can further improve the filtration effect and efficiency of circulating wastewater, thereby improving the mineralization efficiency of seawater desalination products.

[0091] Example 4

[0092] Adopting such Figure 2 The heterogeneous nucleation circulating crystallization granulation fluidized bed system shown is used for mineralization of seawater desalination product. Specifically, the heterogeneous nucleation circulating crystallization granulation fluidized bed system includes a hydrocyclone 7 and the fluidized bed described in Example 3 above. The seed end of the hydrocyclone 7 is connected to the water collection zone 1, and the mineralized water end is connected to the water outlet end of the water collection plate 44.

[0093] Compared to the scheme in Example 3, the heterogeneous nucleation and circulating crystallization granulation fluidized bed system described in this invention can recover crystal seeds in the mineralized reverse osmosis permeate through the water collection zone to the circulating crystallization zone via a hydrocyclone, thereby achieving circulating crystallization granulation.

[0094] The heterogeneous nucleation circulating crystallization granulation fluidized bed and its system provided by this invention treats power plant circulating wastewater (high suspended solids (SS) content) in the filtration zone, purifying the water entering the circulating crystallization zone. Further, under the action of seed crystals, calcium ions in the purified circulating wastewater are removed through the circulating crystallization zone, achieving crystallization granulation. The crystallized granules in the circulating crystallization zone are then transferred to the mineralization zone via a crystallization particle conveying device, where they react under the action of carbon dioxide to produce calcium bicarbonate. The dissolved calcium ions are used to adjust the hardness of the seawater desalination reverse osmosis permeate. Finally, the seed crystals in the mineralized reverse osmosis permeate are recovered through the water collection zone to the circulating crystallization zone for circulating crystallization granulation via a hydrocyclone. Thus, by coupling crystallization granulation and mineralization technologies, the hardness of seawater desalination permeate can be adjusted without the artificial addition of chemical agents, achieving efficient treatment of circulating wastewater and absorbing a large amount of carbon dioxide gas. Furthermore, by removing calcium ions from the purified circulating wastewater, the tendency for calcium salt scaling in subsequent membrane treatment processes can be effectively reduced.

[0095] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A heterogeneous nucleation circulating crystallization granulation fluidized bed, characterized in that, The heterogeneous nucleation circulating crystallization granulation fluidized bed includes a water collection zone (1), a circulating crystallization zone (2), a filtration zone (3), and a mineralization zone (4) that form an integrated structure; The circulating crystallization zone (2) includes an inner cylinder (21), an outer cylinder (22) located outside the inner cylinder (21), an outer cylinder bottom (23) located at the bottom of the outer cylinder (22), and a throat (24) and a flow guide (25) located in the center of the outer cylinder bottom (23). The inlet of the throat (24) is located at the top of the filtration zone (3), and the outlet is located at the bottom of the circulating crystallization zone (2). The circulating crystallization zone (2) and the water collection zone (1) are connected. The filtration zone (3) includes a filter cylinder (31), a filter cylinder bottom (32) disposed at the bottom of the filter cylinder (31), a filtration zone water production main pipe (35) disposed inside the filter cylinder (31), and at least two filter components (36). The filter components (36) are used to filter the circulating wastewater entering the zone. The filtration zone water production main pipe (35) is used to transport the circulating wastewater filtered by the filter components (36) to the circulating crystallization zone (2) through the throat pipe (24). The mineralization zone (4) includes a mineralization cylinder (41), a water distributor plate (43) disposed inside the mineralization cylinder (41) and dividing the mineralization cylinder (41) into upper and lower parts, and a plurality of water distributors (42) disposed on the water distributor plate (43). The nozzles (421) of the water distributors (42) are located in the upper part of the mineralization cylinder (41), and the inlet heads (423) are located in the lower part of the mineralization cylinder (41). A plurality of water inlet heads (423) are provided on the side of the inlet heads (423). An air inlet (424) is provided below the water distributor plate (43) and a guide plate (50) is provided below the guide plate (50). An air inlet (47) is provided below the guide plate (50) and an air inlet (46) is connected to the lower part of the mineralization cylinder (41). A water collection plate (44) is provided at the upper part of the mineralization cylinder (41) for guiding the mineralized water to the outside. The upper part of the mineralization cylinder (41) is connected to the guide component (25) through a crystallization particle conveying device (6).

2. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1, characterized in that, The nozzle (421) has 4-8 spray surfaces on its circumferential side, and each spray surface has 5-9 nozzles.

3. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 2, characterized in that, The nozzle at the center of each spray surface sprays water horizontally, while the other nozzles are tilted outward at a 15-25° angle around the center nozzle.

4. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to any one of claims 1-3, characterized in that, The upper part of the mineralization cylinder (41) is equipped with a crystallization granulation particle monitoring device, which is used to monitor the height of the crystallization granulation particle layer on the water distributor plate (43).

5. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 4, characterized in that, The height of the crystallized granulation layer ranges from 500 to 900 mm.

6. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1 or 5, characterized in that, The water collection tray (44) has a U-shaped basin structure.

7. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1, characterized in that, The crystallization particle conveying device (6) includes an upper particle discharge ring (61), a lower particle discharge ring (63), and a plurality of connecting pipes (62) connecting the upper particle discharge ring (61) and the lower particle discharge ring (63). A crystallization particle discharge control valve (64) is provided on the connecting pipe (62). A plurality of guide pipes are provided at intervals on the inner side of the upper particle discharge ring (61) and the lower particle discharge ring (63). The guide pipe of the upper particle discharge ring (61) is connected to the bottom of the guide component (25) of the circulating crystallization zone (2), and the guide pipe of the lower particle discharge ring (63) is connected to the upper part of the mineralization cylinder (41).

8. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1 or 7, characterized in that, The flow guide component (25) is located at the bottom center of the outer cylinder bottom (23). The flow guide component (25) has a smooth W-shaped cross-section and a through hole in the center for the throat tube (24) to pass through.

9. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1, characterized in that, A lower partition (33) and an upper partition (34) are sequentially arranged above the bottom (32) of the filter cylinder. The outlet of the main water production pipe (35) of the filtration zone is connected to the inlet of the throat pipe (24). The inlet passes through the upper partition (34) and the lower partition (33) and extends into the water production chamber between the lower partition (33) and the bottom (32) of the filter cylinder. One end of the filter shell (361) of the filter component (36) is located above the upper partition (34), and the other end passes through the upper partition (34) and is placed in the water inlet jacket between the upper partition (34) and the lower partition (33). A water production pipe (362) is arranged in the middle of the interior of the filter shell (361). One end of the water pipe (362) passes through the filter shell (361) and the lower partition (33) in sequence and extends into the filter water production chamber. The outer surface of the filter water production pipe (362) above the upper partition (34) is provided with a plurality of filter discs (363). A pressing component (364) is provided on the top of the filter shell (361) to press the filter discs (363) so that filter holes (3631) are formed between adjacent filter discs (363). The filter water production pipe (362) is provided with a plurality of opposing strip holes (3621) along the axial direction. The upper water inlet pipe (365) located outside the filter cylinder (31) communicates with the interior of the filter shell (361) in the water inlet jacket.

10. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 9, characterized in that, The filter component (36) also includes a backwash discharge three-way valve (366) and an upper drain pipe (367); The backwash discharge three-way valve (366) is installed on the upper water inlet pipe (365), the upper sewage pipe (367) is connected to the backwash discharge three-way valve (366), and the filter water production pipe (362) is provided with a plurality of tangential strip holes (3622) along the axial direction.

11. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 9 or 10, characterized in that, The filter water production pipe (362) is a hollow cylinder, and the filter disc (363) is a filter disc with micron-level triangular grooves cast on both sides.

12. The heterogeneous nucleation circulating crystallization granulation fluidized bed according to claim 1, characterized in that, The water collection area (1) includes a water collection cavity (11), a guide ring (12) disposed in the water collection cavity (11), and an upper outlet (13) communicating with the water collection cavity (11).

13. A heterogeneous nucleation circulating crystallization granulation fluidized bed system, characterized in that, The fluidized bed system includes a hydrocyclone (7) and a fluidized bed as described in any one of claims 1-12 above. The seed end of the hydrocyclone (7) is connected to the water collection zone (1), and the mineralized water end is connected to the water outlet end of the water collection plate (44).

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