Circulating cooling water hardness removal device

Abstract

The utility model relates to the technical field of water treatment, and discloses a circulating cooling water hardness removal device which comprises a circulating cooling water settling tank, a circulating cooling water recycling tank, a crystallization and granulation fluidized bed and an ion exchange system, wherein the crystallization and granulation fluidized bed is communicated with the circulating cooling water settling tank, the ion exchange system is respectively communicated with the crystallization and granulation fluidized bed and the circulating cooling water recycling tank, and an ion exchange agent in the ion exchange system is a weakly acidic ion exchange agent; according to the utility model, the weakly acidic ion exchanger and the acidic reagent are used as the regenerant, so that the pH value of the produced water with increased alkalinity after calcium removal treatment by the crystallization and granulation fluidized bed can be adjusted back; therefore, the pH value of the produced water flowing into the circulating cooling water recycling tank subsequently can be equivalent to the pH value of the circulating cooling water which flows out of the self-circulating cooling water settling tank and needs to be treated, so that the circulating cooling water system cannot be damaged.

Description

Technical Field

[0001] The utility model relates to a device for removing hardness from circulating cooling water, belonging to the technical field of water treatment. Background Technique

[0002] A circulating cooling water system is a system used for equipment cooling and heat management, which is widely applied in industries, commerce and various facilities. Its main function is to take away the heat generated by the equipment through circulating cooling water, so as to keep the equipment within a safe working temperature range. At present, during the use of the circulating cooling water system, in order to improve the concentration ratio and ensure the stable operation of the system, scale prevention treatment is required. The currently common scale prevention treatment methods are as follows: direct sewage discharge method, scale inhibitor treatment method, chemical softening treatment and ion exchange method. The above methods have the following disadvantages:

[0003] 1. Direct sewage discharge method: This method is applicable to a narrow range of water quality, with a low concentration ratio, a large amount of sewage discharged, and a large amount of makeup water.

[0004] 2. Scale inhibitor treatment method: The stable limit concentration ratio of this method is low, so that the hardness is not removed, but only the scale formation is delayed. When applied to high-temperature and high-pressure systems, the medium temperature is high, which is likely to cause the scale inhibitor to decompose and fail, resulting in obvious scale formation.

[0005] 3. Chemical softening treatment: This method usually requires a high-density sedimentation tank or a crystallization granulation fluidized bed. This method uses the principle of chemical precipitation, adding alkaline agents such as Na2CO3 and NaOH to the water to react with Ca2+ and Mg2+ in the water to form CaCO3 and Mg(OH)2 precipitates, and reducing the hardness of the water after sedimentation and filtration. At the same time, in order to remove magnesium ions, a large amount of NaOH usually needs to be added to adjust the pH to above 10.5. Since the produced water needs to be recycled to the circulating water system, acid needs to be added to adjust the pH back to about 8, which will thus introduce a large amount of chloride ions, sulfate ions and nitrate ions. The increase in chloride ion concentration will cause chloride ion corrosion problems; the increase in sulfate ion concentration is likely to cause the formation of calcium sulfate scale in the circulating water system, which is difficult to clean; the increase in nitrate ion concentration will cause the increase in the concentration of nitrate nitrogen in the discharged water, resulting in a large increase in the denitrification load of the downstream biochemical system. If the acid is not added to adjust the pH back, the residual alkalinity in the produced water will increase the risk of scale formation in the system, and the free OH- ions will cause intergranular corrosion of the metal materials in the water system, resulting in brittle fracture, called caustic embrittlement, thus triggering accidents such as pipe bursts. In addition, the high-density sedimentation tank process will generate a large amount of sludge that needs to be treated, with problems such as large floor area and high operating costs; when using the crystallization granulation fluidized bed method for treatment, the generated CaCO3 can be discharged in the form of particles, but the Mg(OH)2 precipitate is still discharged in the form of mud and needs to be treated separately.

[0006] 4. Ion exchange method: Although the operating cost is relatively low and a high concentration ratio can be achieved, a regenerated waste liquid with high salt and high hardness needs to be treated. Especially in projects with zero-discharge requirements, the treatment of this waste water will greatly increase the investment and operating costs of the zero-discharge system.

[0007] In the prior art, the invention patent with the Chinese patent authorization announcement number CN116444105B discloses a method for resource pretreatment of high-hardness and high-mineralization coal mine mine water. It first proposes to use a crystallization circulating granulating fluidized bed for this treatment, and then uses a sodium ion exchanger for magnesium removal treatment, so as to achieve the step-by-step recovery of calcium and magnesium ions, achieve the goal of resource utilization, and combined with the membrane method, zero discharge of high-hardness and high-mineralization mine water can be realized. However, the alkalinity of the water treated by this method is relatively high. Since it is directly discharged, the high alkalinity of the treated water will not have an impact. However, when it is applied to a circulating cooling water system, the circulating water with high alkalinity will increase the risk of system scaling, and it is also possible that the metal materials of the water system will undergo intergranular corrosion, resulting in brittle fracture. Therefore, it is not suitable for hardness removal in circulating cooling water. Utility Model Content

[0008] In order to solve the above problems existing in the prior art, the present utility model provides a method and device for removing hardness from circulating cooling water.

[0009] The technical solution of the present utility model is as follows:

[0010] In the first aspect, the present utility model provides a method for removing hardness from circulating cooling water, including the following steps:

[0011] The first step: Add circulating cooling water to a crystallization granulating fluidized bed and add sodium carbonate for calcium removal treatment. When performing calcium removal treatment, there are seed particles in a fluidized state in the crystallization granulating fluidized bed to remove the calcium hardness and part of the bicarbonate hardness in the permanent hardness of the circulating cooling water. By utilizing the characteristics of high mixing intensity and high mass transfer efficiency of the fluidized bed, combined with the added sodium carbonate, carbonate ions can react quickly with calcium ions. Compared with the traditional stirring method for chemical softening, the amount of carbonate ions hydrolyzed into bicarbonate ions can be reduced, so that the pH value of the circulating cooling water entering the crystallization granulating fluidized bed does not need to be adjusted upward, and the pH value of the circulating cooling water discharged after being treated by the crystallization granulating fluidized bed changes little. At the same time, since there are seed particles in a fluidized state in the crystallization granulating fluidized bed, when calcium ions in the circulating cooling water react with sodium carbonate, the produced calcium carbonate can adhere to the surface of the seed particles and grow, thereby reducing the supersaturation required for calcium carbonate crystallization precipitation, and reducing the excess amount of chemicals. Compared with the traditional chemical softening method of first adding liquid alkali to adjust the pH value and then adding soda ash to remove calcium and magnesium ions simultaneously, the increase in the alkalinity of the produced water can be greatly reduced, and the acid consumption required for subsequent alkalinity reduction can also be reduced.

[0012] While controlling the hardness of the produced water, the chemical dosage of the crystallization granulation fluidized bed can be determined according to the hardness and alkalinity values of the influent water and the hardness and alkalinity value requirements of the produced water. By adjusting the chemical dosage (hardness removal amount), the pH value and alkalinity of the produced water can be controlled, thereby enhancing the adaptability of the crystallization granulation fluidized bed to the influent alkalinity.

[0013] Step 2: Add the produced water from the first step into the ion exchange system for removing magnesium hardness and the remaining calcium hardness, and add an acidic reagent as a regenerant. The acidic reagent can be selected from strong acids such as hydrochloric acid and sulfuric acid. In the ion exchange system, a weakly acidic ion exchanger is used. The weakly acidic ion exchanger can be selected from natural ores such as zeolite and sulfonated coal, or can also be selected from weakly acidic cation exchange resins such as polystyrene resins, polycarbamate resins, and crosslinked polyacrylic acid resins. The magnesium hardness and a small amount of calcium hardness that may remain in the produced water will undergo an ion exchange reaction with the H+ ions in the weakly acidic ion exchanger, and thus be adsorbed onto the weakly acidic ion exchanger to achieve the removal of hardness. The exchanged H+ ions can play a role in reducing the pH value and alkalinity of the produced water. The exchanged H+ ions will react with the HCO3- ions in the produced water to form H2CO3. When the magnesium hardness and a small amount of calcium hardness that may remain are adsorbed and saturated on the weakly acidic ion exchanger, a regenerant is introduced to restore the ion exchange capacity of the weakly acidic ion exchanger to ensure the reliability of the ion exchange in the ion exchange system.

[0014] Step 3: Recycle the produced water in the second step. The waste liquid in the second step (i.e., the regenerated waste liquid containing high salt generated after washing the weakly acidic ion exchanger with the regenerant) is discharged to the lower-level treatment system for treatment. The lower-level treatment system is a drying system or a membrane treatment system. When the volume of the waste liquid is small, the high-salt product can be directly dried and obtained for reuse through the drying system. When the volume of the waste liquid is large, the waste liquid is introduced into the membrane treatment system for membrane separation to obtain the high-salt product for reuse.

[0015] In the process of removing calcium hardness in the first step, the calcium hardness will finally be discharged out of the crystallization granulation fluidized bed in the form of calcium carbonate particles, and dehydration and reuse can be achieved through simple water drainage. The calcium hardness and magnesium hardness removed in the second step will be concentrated in the waste liquid, which can prevent sludge generation in the ion exchange system and eliminate the need for additional dehydration equipment.

[0016] In a second aspect, the present invention provides a device for use in the aforementioned method for removing hardness from circulating cooling water, including

[0017] A circulating cooling water settling tank for connecting the circulating cooling water to be treated;

[0018] A circulating cooling water reuse tank for outputting the treated circulating cooling water;

[0019] A crystallization granulation fluidized bed is arranged between a circulating cooling water settling tank and a circulating cooling water reuse tank and is used for removing calcium from the passing circulating cooling water.

[0020] An ion exchange system is arranged between a circulating cooling water settling tank and a circulating cooling water reuse tank and is used for removing magnesium hardness and remaining calcium hardness from the passing circulating cooling water.

[0021] Wherein, the crystallization granulation fluidized bed is communicated with the circulating cooling water settling tank, and the ion exchange system is respectively communicated with the crystallization granulation fluidized bed and the circulating cooling water reuse tank. The ion exchanger in the ion exchange system is selected as a weakly acidic ion exchanger.

[0022] Furthermore, the crystallization granulation fluidized bed and the circulating cooling water settling tank are communicated through a lift pump.

[0023] Furthermore, a seed fluidization tank is communicated with the crystallization granulation fluidized bed through a seed addition pump, and a chemical agent storage tank is communicated with the crystallization granulation fluidized bed through a chemical agent addition pump.

[0024] Furthermore, the crystallization granulation fluidized bed and the ion exchange system are communicated through a filtration system.

[0025] Furthermore, the ion exchange system and the circulating cooling water reuse tank are communicated through a degassing tower.

[0026] Furthermore, a regenerant storage tank is also arranged on the ion exchange system, and the regenerant storage tank and the ion exchange system are communicated through a regenerant addition pump.

[0027] Furthermore, the circulating cooling water settling tank is also directly connected to the circulating cooling water reuse tank through a pipeline.

[0028] Furthermore, the ion exchange system and the filtration system are also communicated through a pipeline, and the circulating cooling water settling tank is also communicated with the ion exchange system and the filtration system through a pipeline.

[0029] The utility model has the following beneficial effects:

[0030] 1. By using a weakly acidic ion exchanger and an acidic reagent as a regenerant, the utility model can adjust the pH value and alkalinity of the water produced after the calcium removal treatment by the crystallization granulation fluidized bed, so that the pH value and alkalinity of the water produced flowing into the circulating cooling water reuse tank subsequently can be equivalent to those of the circulating cooling water to be treated flowing out of the circulating cooling water settling tank, and it hardly causes changes in the pH value and alkalinity of the circulating cooling water, so that it will not damage the circulating cooling water system when flowing into the circulating cooling water system subsequently.

[0031] 2. The utility model can control the alkalinity of the produced water finally recycled to the circulating cooling water reuse tank by adjusting the dosage of the medicament according to requirements, and at the same time, it will not introduce anions such as Cl⁻, SO₄²⁻, NO₃⁻, etc., so as to avoid many side effects such as corrosion and scaling to the circulating cooling water system.

[0032] 3. Compared with the traditional medicament softening process using a high-density sedimentation tank, the utility model can reduce the amount of carbonate hydrolyzed into bicarbonate by only adding sodium carbonate and allowing carbonate ions to react quickly with calcium ions, thereby saving the consumption of medicaments and reducing the overall operating cost.

[0033] 4. Compared with the traditional ion exchange system, the utility model can greatly reduce the amount of waste liquid generated by removing hardness through two-stage processes, thereby greatly reducing the investment and operating costs required for the downstream treatment system. At the same time, removing hardness through two-stage processes can prevent the ion exchange system in this hardness removal method from generating sludge, thereby reducing the overall operating cost.

[0034] 5. The utility model removes hardness through two-stage processes. By adjusting the proportion of hardness removal in the two-stage processes according to actual requirements, it can adapt to a large range of influent alkalinity and improve applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the device used for the hardness removal method in the utility model.

[0036] The reference numerals in the figure are shown as:

[0037] 1. Circulating cooling water sedimentation tank; 2. Circulating cooling water reuse tank; 3. Crystallization granulation fluidized bed; 4. Ion exchange system; 5. Lift pump; 6. Seed addition pump; 7. Seed fluidization tank; 8. Medicament addition pump; 9. Medicament storage tank; 10. Filtration system; 11. Degassing tower; 12. Regenerant storage tank; 13. Regenerant addition pump. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following will describe the utility model in detail with reference to the drawings and specific embodiments.

[0039] Example 1: Please refer to Figure 1, this embodiment provides a device for removing hardness from circulating cooling water, including a circulating cooling water sedimentation tank 1, a circulating cooling water reuse tank 2, a crystallization granulation fluidized bed 3, and an ion exchange system 4. Among them, the circulating cooling water sedimentation tank 1 is used to connect the circulating cooling water to be treated in the external circulating cooling water system. The circulating cooling water reuse tank 2 is used to output the circulating cooling water that has been treated by this hardness removal device. The crystallization granulation fluidized bed 3 is arranged between the circulating cooling water sedimentation tank 1 and the circulating cooling water reuse tank 2, and is used to remove calcium from the passing circulating cooling water. The ion exchange system 4 is arranged between the circulating cooling water sedimentation tank 1 and the circulating cooling water reuse tank 2, and is used to remove magnesium hardness and residual calcium hardness from the passing circulating cooling water.

[0040] In this embodiment, a lift pump 5 is arranged between the crystallization granulation fluidized bed 3 and the circulating cooling water sedimentation tank 1. The water inlet end of the lift pump 5 is communicated with the water outlet end of the circulating cooling water sedimentation tank 1, and the water inlet end of the lift pump 5 is communicated with the liquid inlet end of the crystallization granulation fluidized bed 3. The lift pump 5 can input the circulating cooling water to be treated in the circulating cooling water sedimentation tank 1 into the crystallization granulation fluidized bed 3 for treatment.

[0041] In this embodiment, a seed fluidization tank 7 and a chemical storage tank 9 are also arranged on one side of the crystallization granulation fluidized bed 3. The seed inlet of the crystallization granulation fluidized bed 3 is communicated with the discharge port of the seed fluidization tank 7 through a seed dosing pump 6, and the chemical inlet of the crystallization granulation fluidized bed 3 is communicated with the chemical outlet of the chemical storage tank 9 through a chemical dosing pump 8. The seed dosing pump 6 can input the fluidized seeds in the seed fluidization tank 7 into the crystallization granulation fluidized bed 3 for use, and the chemical dosing pump 8 can input the chemicals in the chemical storage tank 9 into the crystallization granulation fluidized bed 3 for use.

[0042] In this embodiment, a filtration system 10 is arranged between the crystallization granulation fluidized bed 3 and the ion exchange system 4. The liquid inlet end of the filtration system 10 is communicated with the liquid outlet end of the crystallization granulation fluidized bed 3, so that the produced water of the crystallization granulation fluidized bed 3 can flow into the filtration system 10. The liquid outlet end of the filtration system 10 is communicated with the liquid inlet end of the ion exchange system 4. The filtration system 10 can filter the produced water of the passing crystallization granulation fluidized bed 3 to remove colloids and suspended solids in the production. The produced water removed by the filtration system 10 can enter the ion exchange system 4 for corresponding ion exchange.

[0043] In this embodiment, a degassing tower 11 is provided between the ion exchange system 4 and the recycled circulating cooling water tank 2. The liquid inlet end of the degassing tower 11 is communicated with the liquid outlet end of the ion exchange system 4, and the liquid outlet end of the degassing tower 11 is communicated with the liquid inlet end of the recycled circulating cooling water tank 2. The produced water of the ion exchange system 4 can enter the degassing tower 11. The degassing tower 11 can, by means of air blowing by a blower or vacuum pumping by a vacuum pump, etc., enable dissolved gases such as CO2 and O2 to escape from the produced water, thereby reducing the alkalinity of the produced water, which is beneficial to preventing corrosion in the subsequent external circulating cooling water system. The produced water treated by the degassing tower 11 flows into the recycled circulating cooling water tank 2 for recycling, that is, it is input back into the external circulating cooling system.

[0044] In this embodiment, a regenerant storage tank 12 is further provided on one side of the ion exchange system 4. The regenerant storage tank 12 is communicated with the ion exchange system 4 through a regenerant dosing pump 13 provided. The regenerant dosing pump 13 can dose the regenerant in the regenerant storage tank 12 into the ion exchange system 4 for use.

[0045] In this embodiment, the circulating cooling water sedimentation tank 1 can also be directly communicated with the recycled circulating cooling water tank 2 through a pipeline to play a role in shunting, so as to avoid affecting the normal operation of the crystallization granulation fluidized bed 3 when the flow rate of the circulating cooling water is too large.

[0046] In this embodiment, the ion exchange system 4 and the filtration system 10 are also communicated through a pipeline provided. The circulating cooling water sedimentation tank 1 is also communicated with the ion exchange system 4 and the filtration system 10 through a pipeline provided. The setting of these two pipelines is used to pass the backwashing water for the backwashing operations of the filtration system 10 and the ion exchange system 4.

[0047] Embodiment Two: Please refer to Figure 1 , the present utility model provides a method for removing hardness from circulating cooling water, including the following steps:

[0048] First step: Start the lift pump 5 to add the circulating cooling water to be treated in the circulating cooling water sedimentation tank 1 into the crystallization granulation fluidized bed 3, and provide a seed dosing pump 6 and a chemical dosing pump 8 to dose seeds for treating the fluidized state and sodium carbonate into the crystallization granulation fluidized bed 3 to carry out calcium removal treatment, which can remove the calcium hardness and part of the bicarbonate hardness in the permanent hardness of the circulating cooling water to be treated.

[0049] While controlling the hardness of the produced water, the chemical dosage of the crystallization granulation fluidized bed 3 can be determined according to the hardness and alkalinity values of the influent water and the hardness and alkalinity value requirements of the produced water. By adjusting the chemical dosage (hardness removal amount), the pH value of the produced water can be controlled, thereby enhancing the adaptability of the crystallization granulation fluidized bed 3 to the influent water alkalinity.

[0050] In the second step, the produced water of the crystallization granulation fluidized bed 3 is input into the filtration system 10. The filtration system 10 can filter the produced water of the crystallization granulation fluidized bed 3 passing through it to remove colloids and suspended substances in the production. The produced water after being removed by the filtration system 10 is input into the ion exchange system 4.

[0051] In the third step: The produced water entering the ion exchange system 4 is processed in the ion exchange system 4 to remove magnesium hardness and residual calcium hardness. In the ion exchange system 4, a weakly acidic ion exchanger is used. The weakly acidic ion exchanger can be selected as natural ores such as zeolite and sulfonated coal, or can also be selected as weakly acidic cation exchange resins such as polystyrene resins, polycarbamate resins, cross-linked polyacrylic acid resins, etc. The magnesium hardness and a small amount of residual calcium hardness in the produced water will undergo an exchange reaction with the H+ ions in the weakly acidic ion exchanger, and thus be adsorbed onto the weakly acidic ion exchanger to achieve the removal of hardness. The exchanged H+ ions can play a role in reducing the pH value and alkalinity of the produced water. The exchanged H+ ions will react with the HCO3- ions in the produced water to form H2CO3. When the magnesium hardness and a small amount of residual calcium hardness adsorbed on the weakly acidic ion exchanger are saturated, the regenerant dosing pump 13 starts to work. The regenerant dosing pump 13 doses the regenerant in the regenerant storage tank 12 into the ion exchange system 4. The introduced regenerant can wash the weakly acidic ion exchanger to restore the ion exchange capacity of the weakly acidic ion exchanger, that is, wash down the magnesium hardness and calcium hardness adsorbed on the weakly acidic ion exchanger to ensure the reliability of ion exchange in the ion exchange system 4. In this process, waste liquid will be generated. The added regenerant is an acidic reagent, and the acidic reagent can be selected as strong acids such as hydrochloric acid and sulfuric acid.

[0052] In the fourth step: The produced water of the ion exchange system 4 is input into the degassing tower 11. The degassing tower 11 can make dissolved gases such as CO2 and O2 escape from the produced water through methods such as blowing air by a fan or evacuating with a vacuum pump, thereby reducing the alkalinity of the produced water and being beneficial to preventing corrosion in the subsequent external circulating cooling water system. The produced water processed by the degassing tower 11 flows into the circulating cooling water reuse tank 2 for recycling, that is, input back into the external circulating cooling system.

[0053] The waste liquid generated by the ion exchange system 4 (i.e., the regenerated waste liquid containing high salts produced after washing the weakly acidic ion exchanger with the regenerant) is discharged to the lower-level treatment system for treatment. The lower-level treatment system is a drying system or a membrane treatment system. When the volume of the waste liquid is small, high-salt products can be directly dried and obtained for reuse through the drying system. When the volume of the waste liquid is large, the waste liquid is passed into the membrane treatment system for membrane separation to obtain high-salt products for reuse.

[0054] In the first step of removing calcium hardness, the calcium hardness will finally be discharged out of the crystallization granulation fluidized bed 3 in the form of calcium carbonate particles, and dehydration and reuse can be achieved through simple water drainage. The calcium hardness and magnesium hardness removed in the four steps will be concentrated in the waste liquid, which can prevent sludge generation in the ion exchange system 4 and eliminate the need for additional dehydration equipment.

[0055] Taking the influent total hardness of 600 mg / L, alkalinity of 300 mg / L, effluent total hardness of 100 mg / L, and alkalinity of 200 mg / L as an example, the chemical consumption and waste liquid volume of different processes are compared as shown in Table 1 below (unit: mg / L, calculated as calcium carbonate).

[0056] Table 1

[0057]

[0058] In summary, the following points can be obtained:

[0059] 1) Taking the chemical softening process such as the high-density sedimentation tank as an example, to remove the total hardness in water, the pH value needs to be adjusted to above 10.5. Moreover, since the effluent hardness requirement is reduced from 600 mg / L to 100 mg / L, the excess amount of added alkali is relatively large, with the alkali addition amount being 800 mg / L, and the acid addition amount for callback is also relatively large, reaching 400 mg / L. This will introduce a large amount of anions such as Cl−, SO 42 42−, NO3−, etc., subsequently bringing many side effects such as corrosion, scaling in the circulating water system and affecting the biochemical system.

[0060] 2) If only the ion exchange system is used for hardness removal, when hydrochloric acid is used as the regenerant, it will cause negative alkalinity in the effluent, and alkali needs to be added to supplement the alkalinity to avoid equipment corrosion. If sodium chloride is used as the regenerant, the alkalinity cannot be reduced, and acid needs to be added to the effluent, which will introduce anions such as Cl−, SO42−, NO3−, etc., and the volume of the desorption waste liquid is large.

[0061] 3) In the first step of this embodiment, adding sodium carbonate can remove a relatively high part of the hardness in the circulating cooling water (reducing from 600 mg / L to 300 mg / L), with high chemical utilization rate and less excess amount. Then, ion exchange is used to remove the remaining hardness. The H+ ions exchanged can react with the alkalinity of the effluent in the first step, achieving the functions of both hardness removal and alkalinity reduction simultaneously. Compared with processes such as high-density sedimentation, half of the chemicals can be saved. Compared with the traditional ion exchange process, the regeneration waste liquid is only two-fifths of it, which can greatly reduce the treatment scale and cost of the regeneration waste liquid.

[0062] The above description is only an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A circulating cooling water de-hardening device, characterized in that: include A circulating cooling water settling tank (1) for receiving circulating cooling water to be treated; A circulating cooling water recycling tank (2) for outputting the processed circulating cooling water; The crystallization granulation fluidized bed (3) is arranged between the circulating cooling water settling tank (1) and the circulating cooling water reuse tank (2) and is used to remove calcium from the circulating cooling water passing through; An ion exchange system (4) is disposed between the circulating cooling water settling tank (1) and the circulating cooling water reuse tank (2) and is used to remove magnesium hardness and residual calcium hardness from the circulating cooling water; The crystallization granulation fluidized bed (3) is connected to the circulating cooling water settling tank (1), the ion exchange system (4) is connected to the crystallization granulation fluidized bed (3) and the circulating cooling water recycling tank (2), respectively, and the ion exchanger in the ion exchange system (4) is a weakly acidic ion exchanger.

2. A circulating cooling water hardness removal device according to claim 1, characterized in that: The crystallization and granulation fluidized bed (3) is connected to the circulating cooling water sedimentation tank (1) by providing a lifting pump (5).

3. The circulating cooling water hardness removal device according to claim 1, characterized in that: The crystallization and granulation fluidized bed (3) is connected to a crystal seed fluidization tank (7) by arranging a crystal seed dosing pump (6), and is connected to a reagent storage tank (9) by arranging a reagent dosing pump (8).

4. A circulating cooling water hardness removal device according to claim 3, characterized in that: The crystallization and granulation fluidized bed (3) and the ion exchange system (4) are connected by providing a filtering system (10).

5. The circulating cooling water hardness removal device according to claim 1, characterized in that: The ion exchange system (4) is connected to the circulating cooling water reuse tank (2) by providing a degassing tower (11).

6. The circulating cooling water hardness removal device according to claim 1, characterized in that: The ion exchange system (4) is also provided with a regeneration agent storage tank (12), and the regeneration agent storage tank (12) and the ion exchange system (4) are connected by providing a regeneration agent dosing pump (13).

7. The circulating cooling water hardness removal device according to claim 2, characterized in that: The circulating cooling water sedimentation tank (1) is also directly connected to the circulating cooling water reuse tank (2) via a pipeline.

8. The circulating cooling water hardness removal device according to claim 1, characterized in that: The ion exchange system (4) and the filtration system (10) are also connected via a pipeline, and the circulating cooling water sedimentation tank (1) is also connected to the ion exchange system (4) and the filtration system (10) via a pipeline.

Images