Crystallization fluid bed water treatment device

Abstract

A water treatment device for a crystallizing fluidized bed includes a cylindrical body, comprising a lower circulating crystallization reaction section and an upper solid-liquid separation section. The circulating crystallization reaction section is configured with a descending zone and an ascending zone, connected at both ends. The descending zone and / or the ascending zone have multiple wastewater inlets and / or return inlets arranged at multiple points and heights to balance the concentration of pollutants within the cylindrical body while reducing the highest concentration of pollutants. The inflow of water from the wastewater inlets and return inlets provides the kinetic energy for the chemical crystallization and granulation of wastewater and reagents. The solid-liquid separation section is equipped with a return outlet. Particles formed during the chemical crystallization and granulation process are intercepted by the solid-liquid separation section and then settle towards the bottom in the ascending zone, being discharged through the crystal discharge port. This application effectively solves the problems of low crystallization efficiency, easy crystal disintegration, and easy turbidity of effluent in current crystallizing fluidized beds, while also reducing the complexity of the water distribution system and lowering the requirements for equipment height space and foundation bearing capacity.

Description

Technical Field

[0001] This invention belongs to the field of water treatment technology, and in particular refers to a crystallization fluidized bed water treatment device. Background Technology

[0002] Chemical precipitation is a method of removing pollutants from wastewater by adding appropriate reagents to react with the pollutants and form insoluble precipitates. Currently, chemical precipitation is widely used in common water treatment projects such as water softening (hardness removal), phosphate removal, heavy metal ion removal, and fluoride removal due to its maturity, stability, and ease of operation. However, after decades of application, chemical precipitation has also revealed the following drawbacks:

[0003] Chemical precipitation processes need to be used in conjunction with coagulation and sedimentation processes. The process route is relatively long, involves many pieces of equipment, consumes a lot of electricity, and has high maintenance costs.

[0004] The utilization rate of reagents added in chemical precipitation processes is not high, and a large proportion of reagents need to be added in excess, which easily leads to waste.

[0005] The combination of chemical precipitation and coagulation sedimentation processes requires large tank volumes to accommodate high retention times, resulting in a large footprint.

[0006] The sludge produced by chemical precipitation needs to be filtered by pressure, and the moisture content of the sludge is still around 60% after filtration.

[0007] Theoretically, all pollutants that can be chemically precipitated can be removed by crystallization. Therefore, in recent years, numerous fluidized bed crystallization reactors have been used to remove chemically precipitable pollutants such as hardness, fluoride ions, phosphate ions, ammonium ions, and some metal ions. A fluidized bed crystallization reactor is a physicochemical technology that continuously and efficiently induces crystallization by controlling the reaction supersaturation and the flow state of the liquid and solid phases. In the fluidized bed crystallization reactor, wastewater containing the target pollutant, reagents, and seed crystals move in the reactor according to certain patterns. The target pollutant and reagents in the wastewater undergo a chemical reaction on the surface of the seed crystals, causing the seed crystals to grow larger and simultaneously achieving the effect of pollutant removal.

[0008] The fluidized bed crystallization process has the following advantages over chemical precipitation:

[0009] Because the stay time is short (5-30 minutes), the footprint is small and the investment cost is low;

[0010] The equipment is few in number and easy to operate and maintain;

[0011] It has relatively low power consumption and dosage, resulting in lower operating costs.

[0012] After the pollutants crystallize and precipitate, normal draining can reduce the moisture content to less than 15%, greatly reducing the volume of solids.

[0013] However, the current fluidized bed crystallization process also faces the following problems:

[0014] The existing crystallization fluidized bed water distribution and chemical dosing structure is complex and easily damaged, requiring maintenance and replacement every 1-2 years.

[0015] The upflow velocity of existing crystallization fluidized beds is generally controlled between 50 m / h and 120 m / h, which limits the influent flow rate per unit cross-sectional area of ​​the reactor. When the influent flow rate is too large, the upflow velocity exceeds 120 m / h, which will cause small crystals to be washed out.

[0016] Existing crystallization fluidized beds typically have water inlet and chemical dosing at the bottom, resulting in the highest pollutant concentration at the bottom. The pollutant concentration decreases sharply with increasing height, and pollutant removal can be basically completed at a height of 1-3m. However, in order to form a better flow pattern, the height-to-diameter ratio of existing crystallization fluidized bed reactors is usually greater than 3.3, and the height is generally higher than 5.0m, resulting in a significant waste of internal space in the fluidized bed.

[0017] The existing crystallization fluidized bed is generally 5m-30m high, which requires high foundation bearing capacity and installation space, and also generates a large amount of water intake energy consumption;

[0018] Existing crystallizing fluidized beds generally have water inlet and chemical dosing at the bottom. The pollutant concentration and supersaturation are highest at the bottom, which easily leads to primary nucleation and turbidity of the effluent. This drawback is particularly noticeable when the pollutant concentration in the influent is high.

[0019] Existing crystallization fluidized beds generally have water inlet and chemical dosing at the bottom. The pollutant concentration and supersaturation are highest at the bottom, and the crystallization load is the largest at the bottom, which easily leads to loose crystals at the bottom that are easy to disintegrate. This disadvantage is particularly obvious when the pollutant concentration in the influent is high.

[0020] Existing crystallization fluidized beds typically have water and chemicals added at the bottom, resulting in the highest pollutant concentration and supersaturation at the very bottom, leading to the highest crystallization rate. Simultaneously, due to mass limitations, the largest particles also remain at the bottom of the fluidized bed. This results in the largest crystals having the highest crystallization rate, causing the size difference between the bottom and top crystals to widen significantly. Consequently, the upward flow velocity of the crystallization fluidized bed cannot simultaneously meet the technical requirements of suspending and fluidizing large particles at the bottom while preventing small particles at the top from being washed away.

[0021] Currently, the technology for water treatment using chemical precipitation is relatively simple, mainly consisting of chemical reaction + sedimentation or chemical reaction + coagulation sedimentation. The retention time is generally 2.5-4 hours, and the tank volume and footprint are relatively large.

[0022] Patent CN114409141A proposes adding calcium ions to the ash water from the gasification reaction of phosphate / silicate, and then using coagulation and sedimentation for solid-liquid separation to simultaneously remove residual phosphate / silicate.

[0023] Patent CN116514253A proposes to directly add lime milk to high-concentration phosphorus-containing wastewater to react and remove phosphorus, followed by precipitation, so that the total phosphorus content in the wastewater meets the discharge standards.

[0024] Patent CN116119863A proposes to reduce the fluoride concentration in effluent by using lime slurry with a concentration of 3500-4000 mg / L in two stages for defluorination followed by precipitation.

[0025] Patent CN112624432A proposes using sodium sulfide under alkaline conditions in combination with a coagulation and sedimentation process to remove heavy metals;

[0026] Currently, the crystallization fluidized bed process on the market has made significant progress compared with the chemical precipitation method in terms of removal efficiency, investment cost, land area and operating cost. However, problems such as crystal disintegration and turbid effluent still exist, and there is still room for improvement in terms of crystallization efficiency.

[0027] Patent CN116177762A discloses an internally pressurized self-circulating heterogeneous crystallization fluidized bed water treatment device. This device has a typical structure of existing fluidized beds, with the interior divided from bottom to top into an inlet zone, a reagent mixing zone, a reaction reflux zone, and a sedimentation separation zone. The inlet zone is equipped with a seed crystal discharge port and a reagent inlet. This crystallization fluidized bed has a complex water distribution and dosing structure, and suffers from all the disadvantages of bottom inlet and dosing. It has poor volume utilization when treating high and low concentration wastewater, and the effluent is prone to turbidity when treating high concentration wastewater. The crystal structure is also loose and easily disintegrates.

[0028] Patent CN110395824A discloses a device and method for deep phosphorus removal and recovery of secondary effluent from wastewater treatment plants. It utilizes an upward flow of water in a fluidized bed to fluidize a large number of fine HAP seed crystals, forming an induced crystallization zone. Water is fed in from the bottom, and chemicals are added. Mixing and crystallization occur in the induced crystallization zone, thereby removing phosphorus. However, this fluidized bed crystallization system has a complex water distribution and chemical addition structure, and suffers from all the disadvantages of bottom-feed and bottom-addressed systems. Furthermore, it has poor volume utilization when treating low-concentration phosphorus-containing wastewater. Summary of the Invention

[0029] To address the above-mentioned technical problems, the present invention aims to provide a water treatment device for a crystallizing fluidized bed, which can effectively solve the problems of low crystallization efficiency, easy crystal disintegration, and easy turbidity of effluent when high-concentration influent is present in current crystallizing fluidized beds. It also greatly reduces the complexity of the water distribution system, and at the same time, the requirements of crystallizing fluidized bed equipment on height space and foundation bearing capacity can be reduced by lowering the height.

[0030] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0031] A crystallization fluidized bed water treatment device includes a cylindrical body.

[0032] The cylinder includes a lower circulating crystallization reaction section and an upper solid-liquid separation section.

[0033] The circulating crystallization reaction section is provided with a descending zone and an ascending zone, and the two ends of the descending zone and the ascending zone are connected. The descending zone and / or the ascending zone has multiple points and heights of sewage inlet and / or return inlet for balancing the concentration of pollutants in the cylinder and reducing the highest concentration of pollutants in the cylinder. The water inlet of the sewage inlet and the return inlet provides the kinetic energy for the chemical crystallization and granulation of sewage and reagents.

[0034] The solid-liquid separation section is equipped with a clean water outlet and a return water outlet connected to the return water inlet via a pipeline. The particles formed during the chemical crystallization cyclic granulation process are intercepted by the solid-liquid separation section and then settle to the bottom in the rising zone before being discharged through the crystal discharge port.

[0035] In some technical solutions, the sewage inlet and / or return inlet are distributed in the upper, middle and lower parts of the descending zone;

[0036] And / or, the sewage inlet and / or return inlet are distributed to the middle and lower parts of the rising zone.

[0037] In some technical solutions, the sewage inlet includes a first inlet and a second inlet respectively located at the top and middle of the descending zone, and the return inlet includes a return dosing inlet located at the bottom of the descending zone.

[0038] In some technical solutions, the angle between the water flow direction of the first water inlet, the second water inlet, and the return dosing water inlet and the circulating flow direction of the wastewater in the circulating crystallization reaction section is less than 75°, preferably 0-45°.

[0039] In some technical solutions, a partition plate is arranged longitudinally inside the circulating crystallization reaction section, and the partition plate and the inner wall of the cylinder define the descending zone and the ascending zone; and / or,

[0040] The cross-sections of the rising and falling regions are regular geometric shapes, and their dimensions are identical.

[0041] In some technical solutions, a flow channel is formed between the bottom end of the partition plate and the bottom wall of the circulating crystallization reaction section. The height of the flow channel is between 20-2000 mm and the length is between 1.2-10 m.

[0042] In some technical solutions, the solid-liquid separation section is provided with a solid-liquid separation zone, which is connected to the upper middle part of the rising zone. The solid-liquid separation zone is provided with a guide plate assembly and a purified water outlet weir. The guide plate assembly includes a first guide plate located at the connection between the rising zone and the solid-liquid separation zone, a second guide plate located before the return water outlet, and a third guide plate located before the purified water outlet. The purified water outlet weir is located below the purified water outlet. The guide plate assembly and the purified water outlet weir are used to adjust the water flow direction and guide crystal sedimentation.

[0043] In some technical solutions, the height of the cylinder is 1m-12m, preferably 2-6m.

[0044] In some technical solutions, the descending region and / or ascending region also have sampling ports and / or transparent windows arranged at multiple points and heights; and / or,

[0045] A maintenance manhole is provided at the bottom of the descending zone.

[0046] In some technical solutions, during the chemical crystallization cyclic granulation process, the inlet flow velocity of the sewage inlet and the return inlet is controlled above 0.5 m / s, the inlet flow rate of the sewage inlet is controlled at 18-1000 m³ / h, the inlet flow rate of the return inlet is controlled at 40-1200 m³ / h, and the flow velocity in the rising zone is 100 m / h to 1000 m / h.

[0047] The present invention, by employing the above technical solution, has at least the following beneficial effects:

[0048] 1. The crystallization fluidized bed water treatment device proposed in this application balances the pollutant concentration in the reactor by introducing water at multiple points and heights, while reducing the highest concentration of pollutants in the reactor. At the same time, it avoids the highest point of crystallization supersaturation from remaining at the bottom, reducing the probability and number of primary nucleation in the reactor and avoiding turbidity of the effluent. This beneficial effect is particularly obvious when the concentration of pollutants in the influent is high.

[0049] 2. The crystallization fluidized bed water treatment device proposed in this application disperses the area with high supersaturation in the upper, middle and lower sections of the cylinder through high-speed circulation and multi-point water inlet. At the same time, the high-speed circulation is conducive to the full diffusion of the reaction substrate inside the crystallization fluidized bed, avoiding the situation where the bottom has the highest supersaturation, resulting in excessive crystallization load and loose crystals that are easy to disintegrate. This beneficial effect is particularly obvious when the concentration of pollutants in the inlet water is high.

[0050] 3. The crystallization fluidized bed water treatment device proposed in this application uses high-speed circulating multi-point water inlet to make the high supersaturation area not completely overlap with the large crystal area at the bottom of the reaction zone. This allows the small crystals in the upper part of the reaction zone to crystallize rapidly and increase their volume in the high supersaturation area, avoiding the widening of the size difference between the bottom and top crystals, which would make it difficult to control the upward flow velocity. This ensures that the small particles of the required particle size are not washed away, while also ensuring that the large crystal particles at the bottom remain fluidized and do not settle.

[0051] 4. The crystallization fluidized bed water treatment device proposed in this application has a simple water distribution and dosing structure, is not easily damaged, and has a long maintenance cycle;

[0052] 5. The crystallization fluidized bed water treatment device proposed in this application has an upward flow velocity between 100 m / h and 1000 m / h, a wider range of influent flow rates, and a greater water volume that can be treated per unit cross-sectional area;

[0053] 6. The crystallization fluidized bed water treatment device proposed in this application, through the design of multi-point and multi-height water inlet and water inlet method, facilitates the formation of a better fluidization state by high-speed circulation inside the cylinder, which can reduce the height of the cylinder accordingly, complete the crystallization reaction of pollutants in the most efficient range, and reduce the waste of space and height;

[0054] 7. The crystallization fluidized bed water treatment device proposed in this application can control the height of the cylinder to within 6m, which has low requirements for foundation bearing capacity and installation space. At the same time, the required head of the inlet return pump is small, saving energy consumption. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings and their markings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a schematic diagram of the structure of the crystallization fluidized bed water treatment device according to an embodiment of the present invention.

[0057] The meanings of the symbols marked in the figure are as follows:

[0058] 10—Circulating crystallization reaction section, 11—Descending zone, 12—Ascending zone, 13—Separator plate, 141—First water inlet, 142—Second water inlet, 15—Recirculating chemical dosing water inlet, 16—Crystal discharge port, 17—Sampling port, 18—Maintenance manhole, 19—Transparent window;

[0059] 20—Solid-liquid separation section, 211—First guide plate, 212—Second guide plate, 213—Third guide plate, 22—Clean water outlet weir, 23—Return water outlet, 24—Clean water outlet. Detailed Implementation

[0060] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0061] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0062] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0063] In this document, it should be noted that, 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0064] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0065] In one embodiment, please refer to Figure 1 The present invention discloses a crystallization fluidized bed water treatment device, including a cylinder, which can be made of metal or non-metal materials, such as stainless steel, carbon steel or PP material. The cylinder comprises two parts, namely a circulating crystallization reaction section 10 and a solid-liquid separation section 20.

[0066] The internal longitudinal arrangement of the circulating crystallization reaction section 10 includes a partition plate 13, which defines a descending zone 11 and a rising zone 12 between the partition plate 13 and the inner wall of the cylinder. The cross-sections of the descending zone 11 and the rising zone 12 can be regular or irregular geometric shapes such as rectangles and circles, and the shape and area of ​​the rising zone 12 and the descending zone 11 can be different. The two ends of the descending zone 11 and the rising zone 12 are connected. The descending zone 11 and / or the rising zone 12 have multiple sewage inlet and / or return inlet pipes arranged at multiple points and heights to balance the concentration of pollutants in the cylinder and reduce the highest concentration of pollutants in the cylinder. The water inlet of the sewage inlet and the return inlet pipe provides the kinetic energy for the chemical crystallization and granulation of sewage and reagents.

[0067] The solid-liquid separation section 20 is provided with a solid-liquid separation zone, which is connected to the upper middle part of the rising zone 12. The solid-liquid separation zone is provided with a clean water outlet 24 and a return water outlet 23 on both sides. The return water outlet 23 is connected to the return water inlet of the circulating crystallization reaction section 10 through a pipeline. The particles formed in the chemical crystallization cyclic granulation process are intercepted by the solid-liquid separation section 20 and then settle to the bottom in the rising zone and are discharged through the crystal discharge port 16.

[0068] In the above embodiments, the sewage inlet and return inlet are distributed in the upper, middle, and lower parts of the descending zone 11, and can also be distributed in the middle and lower parts of the ascending zone 12. This specific arrangement can ensure the maximum diffusion of the inlet water along the vertical height of the cylinder, and also ensure the stability of the purified water output from the solid-liquid separation zone at the top of the ascending zone 12.

[0069] This application utilizes high-speed circulation with multi-point, multi-height water inlet to balance the pollutant concentration within the reactor while reducing the highest pollutant concentration. This prevents the highest point of supersaturation from remaining at the bottom, reducing the probability and number of primary nucleation sites within the reactor and avoiding turbidity in the effluent. Furthermore, it disperses the high-supersaturation area throughout the upper, middle, and lower sections of the cylinder, using high-speed circulation to ensure sufficient diffusion of the reaction substrate within the crystallization fluidized bed. This avoids the situation where the highest supersaturation at the bottom causes excessive crystallization load, resulting in loose crystals that are prone to disintegration. Moreover, it ensures that the high-supersaturation area within the cylinder does not completely overlap with the large crystal area at the bottom of the reaction zone, allowing small crystals in the upper and middle parts of the reaction zone to rapidly crystallize and increase in volume within the high-supersaturation area. This prevents the size difference between the bottom and top crystals from widening, which would make it difficult to maintain the upward flow velocity. This approach ensures that the required small particles are not washed away while maintaining fluidization at the bottom to prevent sedimentation of large crystal particles.

[0070] In some specific embodiments, the sewage inlet includes a first inlet 141 and a second inlet 142 respectively located at the top and middle of the descending zone 11, and the return inlet includes a return dosing inlet 15 located at the bottom of the descending zone 11. In this arrangement, the return inlet and dosing are carried out simultaneously at the bottom of the descending zone 11, which can dilute the circulating sewage while replenishing the agent, and fully mix it into the rising zone 12 through the reflection effect at the bottom of the cylinder to further remove the tiny pollutants in the sewage.

[0071] In some preferred embodiments, the angle between the inlet water flow direction of the first inlet pipe 141, the second inlet pipe 142, and the return dosing inlet pipe 15 and the circulating flow direction of the wastewater in the circulating crystallization reaction section 10 is less than 75°, preferably 0-45°. In this embodiment, the arrangement at a certain angle allows the inlet water and the circulating wastewater to mix rapidly, and transfers the kinetic energy of the inlet water from the wastewater inlet pipe and the return dosing inlet pipe 15 to the circulating wastewater to provide kinetic energy for circulation.

[0072] In some specific embodiments, a flow channel is formed between the bottom end of the partition plate 13 and the bottom wall of the circulating crystallization reaction section 10. The height of the flow channel is between 20-2000 mm, and the length is between 1.2-10 m. At the same time, by controlling the inlet flow velocity of the sewage inlet and the return inlet to be above 0.5 m / s, the inlet flow rate of the sewage inlet is 18-1000 m3 / h, and the inlet flow rate of the return inlet is 40-1200 m3 / h, so that the flow velocity in the rising zone 12 reaches 100 m / h to 1000 m / h, thereby realizing high-speed circulation inside the cylinder.

[0073] Because the high-speed circulation of this application can form a better fluidization state, the height of the cylinder can be reduced accordingly. This allows for the crystallization reaction of pollutants to be completed within the most efficient range, reducing wasted space and height. Specifically, the height of the cylinder is 1m-12m, preferably 2-6m, and it can be operated as a single unit or in series or parallel with multiple units. This reduces the requirements for foundation bearing capacity and installation space, while the required head of the inlet return pump is small, saving energy.

[0074] In addition, a maintenance manhole 18 is provided at the bottom of the descending zone 11 for maintenance of the pipe opening and equipment; multiple sampling ports 17 and transparent windows 19 are distributed at different heights of the ascending zone 12 and the descending zone 11 for observation and analysis of the morphology and fluidization state of chemical crystal particles.

[0075] In the above embodiment, the solid-liquid separation zone is further provided with a guide plate assembly and a purified water outlet weir 22. The guide plate assembly includes a first guide plate 211 located at the connection between the rising zone 12 and the solid-liquid separation zone, a second guide plate 212 located before the return water outlet 23, and a third guide plate 213 located before the purified water outlet 24. The purified water outlet weir 22 is located below the purified water outlet 24. The guide plate assembly and the purified water outlet weir 22 are used to adjust the water flow direction and guide crystal sedimentation.

[0076] The operating principle of the above-mentioned crystallization fluidized bed water treatment device is further explained below:

[0077] Wastewater enters the descending zone 11 of the circulating crystallization reaction section 10 at a certain flow rate from the top and side wastewater inlet pipes. When it mixes rapidly with the circulating wastewater, it transfers part of its kinetic energy to the circulating wastewater. At the same time, the pollutants in the influent and the reagents in the circulating wastewater crystallize on the seed crystals in the circulating wastewater and flow downwards. During the descent, the concentration of the target pollutants decreases and they are fully mixed with the wastewater. The returned wastewater and the added chemicals enter the bottom of the descending zone of the circulating crystallization reaction section 10 at the intersection of the descending zone and the rising zone 12, through the return chemical inlet 15 at a certain flow rate. Utilizing the reflection effect at the bottom of the cylinder, a region with a relatively high flow velocity (greater than 200 m / h) is formed at the bottom. Simultaneously, this region mixes with the circulating wastewater and enters the rising zone 12. The chemicals and target pollutants in the wastewater crystallize on the fluidized crystals, reacting completely upon passing through the rising zone 12. Subsequently, the wastewater enters the solid-liquid separation zone through the first guide plate 211. Part of the wastewater, after being acted upon by the second guide plate 212, flows back into the return chemical inlet 15 through the return outlet 23. Part of the wastewater is guided by the third guide plate 213 and the purified water outlet weir 22 and discharged through the purified water outlet 24. The crystals carried by the wastewater entering the solid-liquid separation zone flow back to the circulating crystallization reaction section 10 through the slow-flow area created by the guide plate assembly. This cycle repeats continuously.

[0078] Example 1

[0079] The crystallization fluidized bed water treatment device is divided into a circulating crystallization reaction section 10 and a solid-liquid separation section 20. The dimensions of the circulating crystallization reaction section 10 are length × width × height = 2m × 1.5m × 5m, and the dimensions of the solid-liquid separation section 20 are length × width × height = 2m × 1.8m × 1.5m. Inside the circulating crystallization reaction section of the crystallization fluidized bed, a vertical partition plate 13 with a length of 3.2m divides the space into a rising zone 12 with a width of 0.9m and a descending zone 11 with a width of 0.6m. The rising zone 12 and the descending zone 11 are connected vertically. The sewage inlet is located in the descending zone at a height of 4m. At 8m and 2.5m high, the inlet flow rate is 18m³ / h; the reflux dosing inlet 15 is located at the bottom of the descending zone at a height of 0.5m, with a reflux flow rate of 100m³ / h-160m³ / h and a flow velocity of reflux dosing inlet 15 controlled above 5m / s; the maintenance manhole 18 is located at the bottom of the descending zone at a height of 0.6m, the crystal discharge port 16 is located at the bottom of the ascending zone 12 at a height of 0.3m, and the sampling port 17 is located at the ascending zone 12 and the descending zone at heights of 2m and 4m, respectively; the transparent viewing window 19 is located at the ascending zone 12 at a height of 3.5m.

[0080] The guide plate group in the solid-liquid separation zone is located before the return water outlet 23, before the clean water outlet 24, and at the connection point between the solid-liquid separation zone and the rising zone 12, respectively. It plays a role in adjusting the water flow direction and guiding the crystal sedimentation. The clean water outlet 24 and the return water outlet 23 are located on both sides of the solid-liquid separation zone. The clean water outlet weir 22 is 0.3m away from the top of the solid-liquid separation zone and is 0.3m high.

[0081] The distance between the partition plate 13 and the bottom of the circulating crystallization reaction section 10 is 0.2m. When the water flows through the channel with a bottom length of 2m and a width of 0.2m, the flow velocity is between 450m / h and 800m / h.

[0082] The influent hardness is 2000 mg / L, and the effluent hardness is reduced to less than 100 mg / L.

[0083] Example 2

[0084] The differences from Example 1 are as follows: the cylinder size is different, the calcium ion concentration of the inlet and outlet water is different, the inlet flow rate and the return flow rate are different, the transparent window 19 is not set, the number of sampling ports 17 is different, and the position of the inlet pipe is different. For details, please refer to Table 1.

[0085] Example 3

[0086] The differences from Example 1 are as follows: the cylinder size is different, the calcium ion concentration of the inlet and outlet water is different, the inlet flow rate and the return flow rate are different, the number of transparent windows 19 is different, and the number of sampling ports 17 is different. For details, please refer to Table 1.

[0087] Example 4

[0088] The differences from Example 1 are as follows: the cylinder size is different, the calcium ion concentration of the inlet and outlet water is different, the inlet flow rate and the return flow rate are different, the number of transparent windows 19 is different, and the number of sampling ports 17 is different. For details, please refer to Table 1.

[0089] Table 1. Differences between the embodiments

[0090]

[0091] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A crystallization fluidized bed water treatment device, comprising a cylindrical body, characterized in that, The cylinder includes a lower circulating crystallization reaction section and an upper solid-liquid separation section. The internal longitudinal arrangement of the circulating crystallization reaction section is a partition plate, which defines a descending zone and a rising zone between the partition plate and the inner wall of the cylinder. The two ends of the descending zone and the rising zone are connected. The descending zone has multiple sewage inlet ports and return inlet ports arranged at multiple points and heights. The sewage inlet ports include a first inlet port and a second inlet port respectively located at the top and middle of the descending zone. The return inlet port includes a return dosing inlet port located at the bottom of the descending zone. The first inlet port, the second inlet port, and the return dosing inlet port are used to balance the pollutant concentration in the cylinder and reduce the highest pollutant concentration in the cylinder. The angle between the water flow direction of the first inlet port, the second inlet port, and the return dosing inlet port and the circulating flow direction of the sewage in the circulating crystallization reaction section is less than 75°. The water inlet ports of the sewage inlet port and the return inlet port provide the kinetic energy for the chemical crystallization and granulation of sewage and chemicals. The solid-liquid separation section is provided with a clean water outlet and a return water outlet connected to the return water inlet via a pipeline. The solid-liquid separation section is provided with a solid-liquid separation zone, which is connected to the upper middle part of the rising zone. The solid-liquid separation zone is provided with a guide plate assembly and a clean water outlet weir. The guide plate assembly includes a first guide plate located at the connection between the rising zone and the solid-liquid separation zone, a second guide plate located before the return water outlet, and a third guide plate located before the clean water outlet. The clean water outlet weir is located below the clean water outlet. The guide plate assembly and the clean water outlet weir are used to adjust the water flow direction and guide crystal sedimentation. The particles formed in the chemical crystallization cycle granulation process are intercepted by the solid-liquid separation section and then settle to the bottom in the rising zone and are discharged through the crystal discharge port.

2. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, The angle between the water flow direction of the first water inlet, the second water inlet, and the return dosing water inlet and the circulating flow direction of the wastewater in the circulating crystallization reaction section is 0-45°.

3. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, The cross-sections of the rising and falling regions are regular geometric shapes, and their dimensions are identical.

4. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, A flow channel is formed between the bottom end of the partition plate and the bottom wall of the circulating crystallization reaction section. The height of the flow channel is between 20-2000 mm and the length is between 1.2-10 m.

5. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, The height of the cylinder is 1m-12m.

6. The crystallization fluidized bed water treatment device according to claim 5, characterized in that, The height of the cylinder is 2-6m.

7. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, The descending and / or ascending zones also have sampling ports and / or transparent windows arranged at multiple points and heights; and / or, A maintenance manhole is provided at the bottom of the descending zone.

8. The crystallization fluidized bed water treatment device according to claim 1, characterized in that, During the chemical crystallization cyclic granulation process, the inlet flow velocity of the wastewater inlet and the return inlet is controlled above 0.5 m / s, the inlet flow rate of the wastewater inlet is controlled at 18-1000 m³ / h, the inlet flow rate of the return inlet is controlled at 40-1200 m³ / h, and the flow velocity in the rising zone is 100 m / h to 1000 m / h.

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