High-alkalinity low-calcium hard water crystallization softening and water quality upgrading integrated device

Abstract

The application discloses a high-alkalinity low-calcium hard water crystallization softening and water quality improving integrated device, which comprises a crystallization unit, a sedimentation separation unit, a filtration unit and a PH adjusting unit which are sequentially and communicatively arranged along the water flow direction; the crystallization unit comprises a fluidized bed main body, the fluidized bed main body is internally provided with coaxially arranged inner cylinder one and inner cylinder two, the fluidized bed main body is respectively provided with contraction section one and contraction section two, the contraction section one is arranged at the bottom of the inner cylinder one, the contraction section two is arranged between the inner cylinder one and the inner cylinder two, the inner diameters of the contraction section one and the contraction section two are gradually reduced from top to bottom, and the bottoms of the inner cylinder one and the inner cylinder two are respectively provided with flow blocking ring one and flow blocking ring two. Through the arrangement of the inner cylinder one, the inner cylinder two, the contraction section one, the contraction section two, the flow blocking ring one and the flow blocking ring two, a forced circulation path is created, the effective residence time of particles is prolonged, the microcrystals are'recycled' in the bed layer and continue to grow into large particle crystals, the number of microcrystals escaping from the crystallization unit is reduced from the source, the treatment pressure of the subsequent units is directly relieved, and the secondary rebound of the water hardness is prevented.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, specifically to an integrated device for softening and improving the crystallization of high-alkalinity, low-calcium hard water. Background Technology

[0002] With the increasing demands for industrial and drinking water quality, hardness softening has become a core component of water treatment. Compared to traditional chemical precipitation and ion exchange methods, induced crystallization softening technology utilizes seed crystals within a fluidized bed to induce heterogeneous crystallization of calcium and magnesium ions on the seed crystal surface. This technology offers significant advantages such as high operating load, small footprint, and no chemical sludge production (the product is high-purity crystalline particles), aligning with the trend towards green and low-carbon water treatment.

[0003] Crystallization kinetics indicate that calcium ion concentration is the driving force for crystal growth. When the influent calcium content is <100 mg / L and the alkalinity is very high, the crystal growth rate on the seed surface is limited, making primary nucleation and the formation of calcium carbonate microcrystals highly likely. Because these microcrystals are too small to settle effectively in a fluidized bed, they are carried out by the water flow. Furthermore, the lack of sufficient colloidal particles in the water to act as flocculation nuclei means that traditional coagulation and sedimentation processes (such as adding PAC / PAM) have minimal effect on removing these microcrystals.

[0004] Because the pH value of the softened water after crystallization is high, acid must be added to adjust it to meet the requirements of subsequent water use. However, the calcium carbonate microcrystals that were not intercepted in the water are dissolved by acid. This leads to a rebound in hardness and a decrease in softening efficiency. Therefore, these microcrystals must be completely physically separated before adjusting the pH value, but current conventional equipment often overlooks this process timing requirement. Therefore, there is an urgent need to develop an integrated crystallization softening and water quality improvement device for high alkalinity and low calcium hardness. Summary of the Invention

[0005] The present invention aims to at least partially solve one of the technical problems in the above-mentioned technologies.

[0006] Therefore, the purpose of this invention is to propose an integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement. By using two coaxially arranged inner cylinders, a forced circulation path is created, extending the effective residence time of particles. Microcrystals are "recovered" in the bed and continue to grow into large crystal particles, which significantly reduces the number of microcrystals escaping from the crystallization unit from the source, directly alleviating the processing pressure of subsequent units, effectively preventing the secondary rebound of the hardness of the effluent, and ensuring the stability of the softening effect.

[0007] The technical solution of the present invention includes a crystallization unit, a sedimentation separation unit, a filtration unit and a pH adjustment unit arranged sequentially along the water flow direction; The crystallization unit includes a fluidized bed body, within which are coaxially arranged inner cylinder one and inner cylinder two. Both inner cylinder one and inner cylinder two have openings at their tops. The diameter of inner cylinder one is smaller than the diameter of inner cylinder two. The fluidized bed body is provided with a contraction section one and a contraction section two, respectively. Contraction section one is located at the bottom of inner cylinder one, and contraction section two is located between inner cylinder one and inner cylinder two. The inner diameters of both contraction section one and contraction section two gradually decrease from top to bottom. The bottoms of inner cylinder one and inner cylinder two are respectively provided with a flow-blocking ring one and a flow-blocking ring two, both of which are annular with inner diameters gradually increasing from top to bottom.

[0008] Furthermore, the precipitation separation unit includes a precipitation separation component, which is used to perform solid-liquid separation on the microcrystals entrained in the effluent of the crystallization unit, and the top of the precipitation separation component is provided with an overflow weir.

[0009] Furthermore, the bottom of the filter plate is provided with a second water inlet pipe and an air inlet pipe, which are used to perform combined air and water backwashing on the inside of the filter body.

[0010] Furthermore, the pH adjustment unit includes a pH adjustment body, which is connected to an acid dosing tube two. One end of the acid dosing tube two is connected to an acid addition unit, and the other end is connected to multiple release tubes. The acid dosing tube two is used to adjust the pH of the effluent after the microcrystals have been fully removed.

[0011] Furthermore, the fluidized bed body is also equipped with a dosing pipe, a dosing device, and a water distributor. The dosing pipe and the dosing device are used to uniformly add chemicals into the fluidized bed, and the water distributor is used to distribute the water flow in the fluidized bed.

[0012] Furthermore, the filtration unit includes a filtration body, a filter plate is provided inside the filtration body, the top of the filter plate is filled with filter media, and multiple filter heads are provided between the filter plate and the filter media.

[0013] Furthermore, the end of the water inlet pipe away from the filter plate is connected to an acid addition unit, which is used to perform real-time acid washing when scale forms on the filter media.

[0014] Furthermore, it also includes multiple filtration units arranged in parallel, each of which is connected to the outlet side of the sedimentation separation unit and the inlet side of the pH adjustment unit, and the multiple filtration units are used to achieve alternating operation by switching.

[0015] Furthermore, the fluidized bed body is also equipped with a seed crystal feeding pipe and a crystal particle discharge pipe, which are used to feed seed crystals and discharge crystal particles.

[0016] The advantages of this invention compared to existing technologies are: This invention provides an integrated device for softening and improving water quality in high-alkalinity, low-calcium hard water crystallization. Through coaxially arranged inner cylinders one and two, a forced circulation path is created. Water flow carries incompletely grown microcrystalline particles, not simply passing through the reactor once, but circulating multiple times within the bed. This forces microcrystals that did not have time to grow in the primary reaction zone back into the reaction environment, serving as "secondary seed crystals" or cores for continued growth, gaining the opportunity to combine with calcium ions again and grow. By extending the effective residence time of the particles, the microcrystals are "recovered" within the bed and continue to grow into larger crystal particles. This significantly reduces the number of microcrystals escaping from the crystallization unit at the source, directly alleviating the processing pressure on subsequent units, effectively preventing a secondary increase in effluent hardness, and ensuring the stability of the softening effect. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of an integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to the present invention.

[0018] Figure 2 This is a schematic diagram of the modular combination of various functional units in the integrated device for high alkalinity, low calcium hard water crystallization softening and water quality improvement of the present invention.

[0019] As shown in the figure: 1. Crystallization unit; 101. Fluidized bed body; 102. Inlet pipe 1; 103. Dosing pipe; 104. Dosing jacket; 105. Water distributor; 106. Dosing device; 107. Crystallization particle discharge pipe; 108. Baffle ring 1; 109. Seed crystal addition pipe; 110. Connecting ring 1; 111. Inner cylinder 1; 112. Baffle ring 2; 113. Connecting ring 2; 114. Inner cylinder 2; 115. Contraction section 1; 116. Contraction section 2; 2. Sedimentation separation unit; 201. Sedimentation separation assembly; 20 2. Overflow weir; 3. Filtration unit; 301. Filter body; 302. Drain pipe; 303. Filter media inlet pipe; 304. Filter media layer; 305. Filter media outlet pipe; 306. Filter head; 307. Filter plate; 308. Water inlet pipe II; 309. Air inlet pipe; 310. Connecting pipe; 4. Acid addition unit; 401. Acid storage tank; 402. Acid dosing pump; 403. Acid dosing pipe I; 5. pH adjustment unit; 501. pH adjustment body; 502. Water outlet pipe; 503. Acid dosing pipe II; 504. Release pipe. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses consistent with some aspects of this disclosure as detailed in the appended claims.

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 As shown, this embodiment proposes an integrated device for high alkalinity, low calcium hard water crystallization softening and water quality improvement, including a crystallization unit 1, a sedimentation separation unit 2, a filtration unit 3 and a pH adjustment unit 5 arranged sequentially along the water flow direction; Crystallization unit 1 includes a fluidized bed body 101. Inside the fluidized bed body 101, there are two inner cylinders, one 111 and the other 114, arranged coaxially. The tops of both inner cylinders 111 and 114 are open. The diameter of inner cylinder 111 is smaller than that of inner cylinder 114. The fluidized bed body 101 is provided with a contraction section 115 and a contraction section 116. The contraction section 115 is located at the bottom of inner cylinder 111, and the contraction section 116 is located between inner cylinders 111 and 114. The inner diameters of both contraction sections 115 and 116 gradually decrease from top to bottom. The bottoms of inner cylinders 111 and 114 are provided with a flow-blocking ring 108 and a flow-blocking ring 112, respectively. Both the flow-blocking ring 108 and the flow-blocking ring 112 are annular rings with inner diameters gradually increasing from top to bottom.

[0023] It should be noted that the length of inner cylinder 111 is greater than that of inner cylinder 2 114, thereby extending the effective residence time of the particles. The microcrystals are "recovered" in the bed and continue to grow into large-particle crystals, which greatly reduces the number of microcrystals escaping from the crystallization unit and directly alleviates the processing pressure of subsequent units.

[0024] Specifically, the dealkali-treated water is pumped into the fluidized bed body 101 via a water pump and inlet pipe 102. Seed crystals are then introduced into the fluidized bed body 101 via seed crystal addition pipe 109. The main components of the seed crystals are garnet, calcite, dolomite, or one of the following: artificially synthesized seed crystals. The seed crystals are used to induce calcium carbonate crystallization, provide crystallization sites, control the crystallization process, and improve product quality. Within the fluidized bed body 101, coaxially arranged inner cylinders 111 and 114, as well as constriction sections 115 and 116, form a two-stage forced internal circulation flow path. When the water flows through constriction section 115, the flow rate decreases due to its funnel-shaped shape, causing large seed crystals to sink while simultaneously blocking… The flow ring 108 is an annular shape with an inner diameter that gradually increases from top to bottom. This increases the water flow velocity in the middle of the flow ring 108, thus pushing the large sedimentary crystal particles back into the inner cylinder 111 for crystallization, forming a single cycle. The water flows through the narrow slit between the flow ring 108 and the flow ring 112 multiple times under the negative pressure. The inner cylinder 114 has the same circulation method as the inner cylinder 111. Through the cooperation of the inner cylinder 111 and the inner cylinder 114, a two-stage forced circulation path is formed, which causes calcium ions to crystallize heterogeneously on the surface of the crystal particles and continuously granulate and grow. This significantly reduces the number of microcrystals escaping from the crystallization unit from the source, directly alleviating the treatment pressure of subsequent units, effectively preventing a secondary increase in the hardness of the effluent, and ensuring the stability of the softening effect.

[0025] Furthermore, the fluidized bed body 101 is also provided with a dosing pipe 103, a dosing device 106, and a water distributor 105. The dosing pipe 103 and the dosing device 106 are used to uniformly add chemicals into the fluidized bed, and the water distributor 105 is used to distribute the water flow in the fluidized bed.

[0026] Furthermore, the fluidized bed body 101 is also provided with a seed crystal addition pipe 109 and a crystal particle discharge pipe 107, which are used to add seed crystals and discharge crystal particles.

[0027] The dosing pipe 103 passes through the fluidized bed body 101 and is connected to the dosing jacket 104. The top of the dosing jacket 104 is connected to multiple dosing devices 106 and water distributors 105. The dosing pipe 103, the dosing jacket 104 and the dosing devices 106 are used to uniformly add chemicals into the fluidized bed, and the water distributors 105 are used to distribute the water flow in the fluidized bed.

[0028] It should be noted that, within the fluidized bed reaction zone, alkaline agents are added. The main components of these agents are NaOH or Na2CO3. These agents primarily regulate the chemical environment of the water, converting calcium ions in the water into solid calcium carbonate crystals, thereby softening the water and removing calcium ions, maintaining the pH of the water in the reaction zone within the range of 9.2–9.6. By setting up a two-stage forced internal circulation granulation structure with inner cylinder 111 and inner cylinder 114 in crystallization unit 1, a graded and enhanced crystallization environment is provided for the removal of calcium and magnesium ions in the water. Microcrystals that do not undergo crystallization circulation granulation in inner cylinder 111 escape to inner cylinder 114 for secondary crystallization circulation granulation, improving the growth efficiency of the crystal particles. Calcium ions undergo heterogeneous crystallization on the seed crystal surface and gradually form calcium carbonate crystal particles. The crystallized particles are periodically discharged through the crystal particle discharge pipe 107.

[0029] The crystallization reaction in this process is represented by the following equation: Ca 2+ +CO3 2- →CaCO3↓ Under these simulated conditions, the concentration of calcium ions in the water can be reduced from 65-75 mg / L to approximately 25-35 mg / L. A small amount of calcium carbonate microcrystals may be carried in the crystallized water, which significantly reduces the number of microcrystals escaping from crystallization unit 1 at the source, directly alleviating the treatment pressure of subsequent units, effectively preventing a secondary increase in the hardness of the effluent, and ensuring the stability of the softening effect.

[0030] To clearly illustrate the previous embodiment, in one embodiment of the present invention, the precipitation separation unit 2 includes a precipitation separation component 201, the top of which is provided with an overflow weir 202. The precipitation separation unit 2 is used to perform solid-liquid separation on the microcrystals entrained in the effluent of the crystallization unit 1.

[0031] It should be noted that the sedimentation separation assembly includes a sedimentation separation body and an inclined plate / pipe component disposed inside it. The inclined plate / pipe component and the overflow weir 202 are used to perform solid-liquid separation on the microcrystals entrained in the effluent of the crystallization unit 1.

[0032] To clearly illustrate the previous embodiment, in one embodiment of the present invention, the filter unit 3 includes a filter body 301, a filter plate 307 is provided inside the filter body 301, the top of the filter plate 307 is filled with filter media [A3.1], and a plurality of filter heads 306 are provided between the filter plate 307 and the filter media.

[0033] Furthermore, the bottom of the filter plate 307 is provided with a water inlet pipe 308 and an air inlet pipe 309, which are used to perform combined air and water backwashing on the inside of the filter body 301.

[0034] Furthermore, the end of the water inlet pipe 308 away from the filter plate 307 is connected to an acid addition unit 4, which is used to perform real-time acid washing when scale forms on the filter media.

[0035] It should be noted that the acid addition unit 4 includes an acid dosing pump. The outlet of the acid dosing pump 402 is connected to the inlet pipe 308 through the acid dosing pipe 403. The inlet of the acid dosing pump 402 is connected to an acid storage tank 401. The main components of the acid are hydrochloric acid or sulfuric acid. The main function of the acid is to dissolve the calcium carbonate microcrystals that were not completely removed in the previous step, ensuring that the turbidity of the effluent is within a safe range.

[0036] Furthermore, it also includes multiple filter units 3 arranged in parallel. All filter units 3 are connected to the outlet side of the sedimentation and separation unit 2 and the inlet side of the pH adjustment unit 5. The multiple filter units 3 are used to achieve alternating operation by switching.

[0037] It should be noted that multiple filter units 3 are connected to the outlet side of the sedimentation and separation unit 2 and the inlet side of the pH adjustment unit 5, and the water flow channels are switched via switching valves. During normal operation, when one filter unit 3 is backwashed, the inlet water is automatically or manually switched to another parallel filter unit 3 via the switching valves, thus ensuring that the entire integrated device can continue to operate without shutdown during the backwashing of filter units 3. After backwashing, the backwashed filter unit 3 can be put back into operation, while another filter unit 3 can enter the backwashing state as needed according to the operating cycle, realizing the alternating operation of filter units 3. Through the above-mentioned parallel filter unit 3 configuration, the device improves the continuity and stability of system operation while ensuring filtration effect, making it suitable for engineering applications with high requirements for continuous water supply.

[0038] Furthermore, the pH adjustment unit 5 includes a pH adjustment body, which is connected to an acid dosing pipe 2 503. One end of the acid dosing pipe 2 503 is connected to the acid addition unit 4, and the other end is connected to multiple release pipes 504. The acid dosing pipe 2 503 is used to adjust the pH of the effluent after the microcrystals have been fully removed.

[0039] It should be noted that one end of acid dosing pipe 2 503 is connected to acid dosing pipe 1 403, and the other end is connected to multiple release pipes 504. The pH adjustment unit is equipped with an outlet pipe 502. Filtered water enters the pH adjustment unit 5 through connecting pipe 310. Acid is added to the water through acid dosing pipe 2 503 within the pH adjustment unit to finely adjust the pH of the effluent, which is then discharged through outlet pipe 502. Because the microcrystals are sufficiently physically intercepted before pH adjustment, the problem of increased hardness caused by acid dissolution of the microcrystals is effectively avoided.

[0040] Specifically, the water treated by the sedimentation and separation unit 2 and the filtration unit 3 enters the pH adjustment unit 5, where acid is added to adjust the pH of the effluent to the range of 7.2 to 7.6. Since the microcrystals have been effectively removed in the preceding units, there is no significant re-dissolution of calcium ions in the water during this pH adjustment process, and the calcium ion concentration in the effluent remains at approximately 25 to 35 mg / L.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0043] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. An integrated device for softening and improving water quality in high-alkalinity, low-calcium hard water crystallization, characterized in that, It includes a crystallization unit, a sedimentation separation unit, a filtration unit, and a pH adjustment unit that are sequentially connected along the water flow direction; The crystallization unit includes a fluidized bed body, within which are coaxially arranged inner cylinder one and inner cylinder two. Both inner cylinder one and inner cylinder two have openings at their tops. The diameter of inner cylinder one is smaller than the diameter of inner cylinder two. The fluidized bed body is provided with a contraction section one and a contraction section two, respectively. Contraction section one is located at the bottom of inner cylinder one, and contraction section two is located between inner cylinder one and inner cylinder two. The inner diameters of both contraction section one and contraction section two gradually decrease from top to bottom. The bottoms of inner cylinder one and inner cylinder two are respectively provided with a flow-blocking ring one and a flow-blocking ring two, both of which are annular with inner diameters gradually increasing from top to bottom.

2. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to claim 1, characterized in that: The filtration unit includes a filtration body, a filter plate inside the filtration body, filter media filling the top of the filter plate, and multiple filter heads between the filter plate and the filter media.

3. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to claim 2, characterized in that: The bottom of the filter plate is provided with a second water inlet pipe and an air inlet pipe, which are used to perform combined air and water backwashing on the inside of the filter body.

4. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to claim 3, characterized in that: The end of the water inlet pipe away from the filter plate is connected to an acid addition unit, which is used to perform real-time acid washing when scale forms on the filter media.

5. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to claim 4, characterized in that: The pH adjustment unit includes a pH adjustment body, which is connected to an acid dosing tube 2. One end of the acid dosing tube 2 is connected to an acid addition unit, and the other end is connected to multiple release tubes. The acid dosing tube 2 is used to adjust the pH of the effluent after the microcrystals have been fully removed.

6. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to any one of claims 1-5, characterized in that: It also includes multiple filtration units arranged in parallel, each of which is connected to the outlet side of the sedimentation and separation unit and the inlet side of the pH adjustment unit. The multiple filtration units are used to achieve alternating operation by switching.

7. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to any one of claims 1-5, characterized in that: The fluidized bed body is also equipped with a dosing pipe, a dosing device, and a water distributor. The dosing pipe and the dosing device are used to uniformly add chemicals into the fluidized bed, and the water distributor is used to distribute the water flow in the fluidized bed.

8. The integrated device for high-alkalinity, low-calcium hard water crystallization softening and water quality improvement according to any one of claims 1-5, characterized in that: The fluidized bed body is also equipped with a seed crystal addition pipe and a crystal particle discharge pipe, which are used to add seed crystals and discharge crystal particles.

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