Continuous hardness removal and regeneration device for weak acid cation bed

Abstract

The utility model belongs to the technical field of hardness removal and regeneration of weak acid cation beds, and particularly relates to a continuous hardness removal and regeneration device of a weak acid cation bed, which is characterized in that two or more than two weak acid cation beds are connected in parallel; each weak acid cation bed runs alternately in time according to the steps of hardness removal, acid washing regeneration, produced water flushing, alkali washing regeneration and produced water re-flushing, hardness removal and regeneration are carried out continuously, waste acid and waste alkali generated during regeneration of the weak acid cation bed are utilized to regenerate the weak acid cation bed, and then good acid liquor and good alkali liquor are utilized to regenerate the weak acid cation bed. The waste acid liquor and the waste alkali liquor are fully utilized, and meanwhile, the consumption of good acid liquor and good alkali liquor is reduced; according to the high-hardness water hardness removal device, consumption of acid liquor and alkali liquor for high-hardness water hardness removal is greatly reduced, waste of acid and alkali resources caused by neutralization of waste acid liquor and waste alkali liquor is avoided, and the waste acid and alkali resources are effectively utilized; the weak acid cation bed device disclosed by the utility model can be used for continuously and circularly removing hardness and regenerating, so that continuous hardness removal production of high-hardness water is realized.

Description

Technical Field

[0001] The utility model belongs to the technical field of hard removal and regeneration of weak acid cation beds, and specifically relates to a device for continuous hard removal and regeneration of a weak acid cation bed. Background Art

[0002] During the production process of coal chemical enterprises, a lot of high-hardness wastewater is generated. In order to recycle this part of high-hardness wastewater, it is necessary to reduce its hardness. Or, the boiler soft water in the production process of coal chemical enterprises needs hard removal treatment. The weak acid cation exchange resin has a weak reactive group such as a hydroxyl group (-COOH group). This ion exchange resin can only exchange cations in weak bases such as Ca2+ and Mg2+, and cannot exchange ions in strong bases such as Na+ and K+. Therefore, the weak acid cation exchange resin is used to remove the hardness of high-hardness wastewater or prepare boiler soft water. However, during the actual industrial production process of hard removal of wastewater or preparation of soft water, the weak acid cation exchange resin bed (referred to as the cation bed) needs to be regenerated, which will generate a large amount of waste acid and waste alkali. This part of waste acid and waste alkali is difficult to utilize, bringing the problem of treating waste acid and waste alkali to the enterprise. The neutralization of waste acid and waste alkali causes waste of acid resources and alkali resources. Content of the Utility Model

[0003] Based on the problems of the existing technology, the utility model provides a device for continuous hard removal and regeneration of a weak acid cation bed. The utility model enables the weak acid cation bed device to continuously and cyclically remove hardness and regenerate. At the same time, the weak acid cation bed wastes less acid resources and alkali resources, reducing the treatment amount of waste acid and waste alkali.

[0004] In order to solve the above technical problems, the technical solution of the utility model is as follows:

[0005] A device for continuous hard removal and regeneration of a weak acid cation bed, comprising a weak acid cation bed, an acid tank, an alkali tank, a recycled acid tank, a recycled alkali tank, and a wastewater tank. Two or more weak acid cation beds are provided and are connected in parallel. The upper water inlet of each weak acid cation bed is connected to the incoming water pipeline through a pipeline. The bottom inlet and outlet of each weak acid cation bed are connected to the inlet of the product water tank through a pipeline. The outlet of the product water tank is connected to the bottom inlet and outlet of each weak acid cation bed through a product water pump, and the outlet of the product water pump is also connected to the downstream device through pipeline a; The bottom inlet and outlet of each weak acid cation bed are communicated with the acid tank through an acid pipeline, and the bottom inlet and outlet of each weak acid cation bed are communicated with the alkali tank through an alkali pipeline. Each weak acid cation bed is provided with two upper outlets and one middle outlet. The two upper outlets are respectively the upper outlet a and the upper outlet b. The upper outlet a and the middle outlet are respectively communicated with the recycled acid tank, the recycled alkali tank, and the wastewater tank through pipelines. The upper outlet b is communicated with the wastewater tank through a pipeline; The recycled acid tank is communicated with the bottom inlet and outlet of the weak acid cation bed through a pipeline and a recycled acid pump. The recycled alkali tank is communicated with the bottom inlet and outlet of the weak acid cation bed through a pipeline and a recycled alkali pump; The bottom inlet and outlet of the weak acid cation bed are also connected to the water inlet of the buffer water tank through a pipeline. The water outlet of the buffer water tank is connected to the incoming water pipeline through a buffer water pump; The wastewater tank is connected to the downstream wastewater treatment device through a wastewater pump and a wastewater pipeline.

[0006] Further, acid pumps and alkali pumps are respectively arranged on the pipelines connecting the weak acid cation bed with the acid tank and the alkali tank.

[0007] Further, acid-base concentration meters are arranged on the pipelines connected to the upper outlet a, the upper outlet b, and the middle outlet of each weak acid cation bed; Acid-base concentration meters are arranged on the pipelines connecting the bottom inlet and outlet of the weak acid cation bed with the recycled acid tank and the recycled alkali tank; Acid-base concentration meters are arranged on both the acid pipeline and the alkali pipeline.

[0008] Further, a liquid level detection device is arranged on the weak acid cation bed.

[0009] Further, an air suction and exhaust port is arranged at the top of the weak acid cation bed.

[0010] Further, an automatic control device is further included, and the automatic control device is connected to the device for continuous hard removal and regeneration of the weak acid cation bed.

[0011] Further, one or more recycled acid tanks and one or more recycled alkali tanks are respectively provided to collect waste acid liquid and waste alkali liquid with different concentrations. Beneficial effects

[0012] 1. The utility model realizes continuous hardness removal and regeneration by arranging two or more weak acid cation exchangers in parallel, and each weak acid cation exchanger operates staggeredly in time according to the steps of hardness removal, pickling regeneration, product water flushing, caustic washing regeneration, and product water re-flushing, so as to make the hardness removal and regeneration continuous. The waste acid liquid and waste alkali liquid generated during the regeneration process of the cation exchanger are used to regenerate the weak acid cation exchanger, and then good acid liquid and good caustic washing are used for regeneration, so that the waste acid liquid and waste alkali liquid can be fully utilized, and at the same time, the consumption of good acid liquid and good caustic liquid is also reduced. The utility model greatly reduces the consumption of acid liquid and alkali liquid for hardness removal of high-hardness water, and at the same time effectively utilizes waste acid resources and waste alkali resources, avoiding the waste of acid resources and alkali resources caused by the neutralization of waste acid liquid and waste alkali liquid.

[0013] 2. The utility model avoids a large amount of wastewater generated by the neutralization of waste acid liquid and waste alkali liquid by recycling waste acid liquid and waste alkali liquid. In addition, the utility model arranges a buffer water tank to collect the drained water in the weak acid cation exchanger after hardness removal, the drained water in the weak acid cation exchanger after product water flushing, and the drained water in the weak acid cation exchanger after product water re-flushing, and sends the water collected in the buffer water tank into the weak acid cation exchanger for hardness removal again, also avoiding the conversion of this part of water into wastewater.

[0014] 3. The invention arranges a plurality of recycled acid tanks and recycled alkali tanks to collect waste acid liquid and waste alkali liquid with different concentrations respectively. When regenerating the cation exchanger, the weak acid cation exchanger is first regenerated with low-concentration waste acid liquid or waste alkali liquid, then regenerated with high-concentration waste acid liquid or waste alkali liquid, and finally regenerated with good acid liquid or good caustic liquid, so as to form a cascade utilization of waste acid liquid or waste alkali liquid from low concentration to high concentration, and make the low-concentration waste acid liquid or waste alkali liquid converted into wastewater as much as possible when regenerating the weak acid cation exchanger.

[0015] 4. The weak acid cation exchanger device of the utility model can continuously and cyclically remove hardness and regenerate, realizing continuous hardness removal production of high-hardness water and obtaining low-hardness water or soft water. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is the structural schematic diagram a of the utility model;

[0017] Figure 2 is the structural schematic diagram b of the utility model;

[0018] Figure 3 is the structural schematic diagram c of the utility model;

[0019] Figure 4 is the structural schematic diagram d of the utility model;

[0020] In the figure: 1 - weak acid cation bed a; 2 - weak acid cation bed b; 3 - weak acid cation bed c; 4 - weak acid cation bed d; 5 - weak acid cation bed e; 6 - weak acid cation bed f; 7 - product water tank; 8 - product water pump; 9 - pipeline a; 10 - buffer water pump; 11 - buffer water tank; 12 - alkali pump; 13 - alkali tank; 14 - acid pump; 15 - acid tank; 16 - recycled acid pump; 17 - recycled acid tank; 18 - recycled alkali pump; 19 - recycled alkali tank; 20 - waste water tank; 21 - waste water pump; 22 - incoming water pipeline; 23 - waste water pipeline. Detailed implementation manner Example 1

[0021] Refer to Figure 1, in order to reduce the consumption of acid solution and alkali solution during the hard removal process of the weak acid cation bed, fully utilize the waste acid solution and waste alkali solution generated during the regeneration process of the weak acid cation bed, reduce the treatment volume of the waste acid solution and waste alkali solution, and reduce the production cost.The utility model provides a device for continuous hard removal and regeneration of a weak acid cation exchanger bed, which includes a weak acid cation exchanger bed, an acid tank 15, an alkali tank 13, a recycled acid tank 17, a recycled alkali tank 19, a wastewater tank 20, and an automatic control device. The automatic control device is connected to the device for continuous hard removal and regeneration of the weak acid cation exchanger bed, and controls the automatic operation of the device of the utility model. Two weak acid cation exchanger beds are provided, namely a weak acid cation exchanger bed a1 and a weak acid cation exchanger bed b2. The two weak acid cation exchanger beds are connected in parallel. The upper water inlet of each weak acid cation exchanger bed is connected to the incoming water pipeline 22 through a pipeline. The bottom inlet and outlet of each weak acid cation exchanger bed are connected to the inlet of the product water tank 7 through a pipeline. The outlet of the product water tank 7 is connected to the bottom inlet and outlet of each weak acid cation exchanger bed through a product water pump 8. The outlet of the product water pump 8 is also connected to the downstream device through a pipeline a9. The bottom inlet and outlet of each weak acid cation exchanger bed are communicated with the acid tank 15 through an acid pipeline, so that a hydrochloric acid solution with a mass concentration of 3% - 9% can be added to the weak acid cation exchanger bed. The bottom inlet and outlet of each weak acid cation exchanger bed are communicated with the alkali tank 13 through an alkali pipeline, so that a sodium hydroxide solution with a mass concentration of 3% - 9% can be added to the weak acid cation exchanger bed. Acid pumps 14 and alkali pumps 12 are respectively arranged on the pipelines connecting the weak acid cation exchanger bed with the acid tank 15 and the alkali tank 13. Each weak acid cation exchanger bed is provided with two upper outlets and one middle outlet. The two upper outlets are respectively the upper outlet a and the upper outlet b. The upper outlet a and the middle outlet are respectively communicated with the recycled acid tank 17, the recycled alkali tank 19, and the wastewater tank 20 through pipelines. The upper outlet b is communicated with the wastewater tank 20 through a pipeline. The upper outlet a is used for discharging liquid during alkali washing regeneration, so that the wastewater generated during alkali washing flows into the wastewater tank 20, and the waste alkali generated when the alkali solution penetrates the weak acid cation exchanger bed during alkali washing flows into the recycled alkali tank 19. The upper outlet b is used for discharging liquid during product water flushing and product water re-flushing. The middle outlet is used for discharging liquid during acid washing regeneration, so that the wastewater generated during acid washing flows into the wastewater tank 20, and the waste acid generated when the acid penetrates the weak acid cation exchanger bed during acid washing flows into the recycled acid tank 17. The setting position of the upper outlet b is related to the height of shrinkage of the weakly acidic cation exchange resin after acid washing regeneration, so that the weakly acidic cation exchange resin can just be submerged by acid after the acid washing regeneration is completed. The recycled acid tank 17 is communicated with the bottom inlet and outlet of the weak acid cation exchanger bed through a pipeline and a recycled acid pump 16, so that the waste acid liquid can be recycled for acid washing regeneration of the weak acid cation exchanger bed. The recycled alkali tank 19 is communicated with the bottom inlet and outlet of the weak acid cation exchanger bed through a pipeline and a recycled alkali pump 18, so that the waste alkali liquid can be recycled for alkali washing regeneration of the weak acid cation exchanger bed. The bottom inlet and outlet of the weak acid cation exchanger bed are also communicated with the inlet of a buffer water tank 11 through a pipeline. The outlet of the buffer water tank 11 is connected to the incoming water pipeline 22 through a buffer water pump 10. The buffer water tank 11 is used for collecting the drained water in the weak acid cation exchanger bed after hard removal, the drained water in the weak acid cation exchanger bed after product water flushing, and the drained water in the weak acid cation exchanger bed after product water re-flushing, and sending the water collected in the buffer water tank 11 into the weak acid cation exchanger bed for re-hard removal. The wastewater tank 20 is connected to the downstream wastewater treatment device through a wastewater pump 21 and a wastewater pipeline 23.

[0022] An acid-base concentration meter is provided on the pipelines connected to the upper outlet a, upper outlet b, and middle outlet of each weak acid cation bed; acid-base concentration meters are provided on the acid pipeline and the base pipeline; an acid-base concentration meter is provided on the pipeline connecting the bottom liquid inlet and outlet of the weak acid cation bed to the recycled acid tank 17 and the recycled base tank 19; a liquid level detection device is provided on the weak acid cation bed; an air suction and exhaust port is provided at the top of the weak acid cation bed to facilitate exhaust during liquid inlet and air suction during liquid outlet of the weak acid cation bed.

[0023] A method for continuous hard removal and regeneration of a weak acid cation bed is realized through a device for continuous hard removal and regeneration of a weak acid cation bed, and includes the following steps:

[0024] (1) Hard removal: High-hardness water enters from the top of the weak acid cation bed, and hard removal is carried out in the weak acid cation bed. After hard removal, produced water is obtained, and the produced water flows out from the bottom liquid inlet and outlet of the weak acid cation bed and enters the produced water tank 7; the weakly acidic cation exchange resin filled in the weak acid cation bed undergoes hard removal for a period of time. The calcium and magnesium ions in the high-hardness water are exchanged with the sodium ions in the weakly acidic cation exchange resin, and the weakly acidic cation exchange resin is converted from the sodium type to the calcium-magnesium type. The weakly acidic cation exchange resin loses its hard removal performance. At this time, the high-hardness water is switched through a valve to enter the next weak acid cation bed for hard removal, and the high-hardness water in the weak acid cation bed that has lost its hard removal performance is discharged into the buffer water tank 11.

[0025] (2) Pickling regeneration: The weak acid cation bed at the end of hard removal in step (1) is passed through waste acid solution for pickling regeneration to form regeneration liquid a. The regeneration liquid a is discharged into the waste water tank 20 through the middle outlet. When the acid-base concentration meter detects that the acid concentration of the regeneration liquid a is 0.01%, the regeneration liquid a is made to enter the recycled acid tank 17 by switching the valve. As the pickling regeneration progresses, the acid-base concentration meter detects that the acid concentration of the regeneration liquid a gradually increases. When the acid concentration of the regeneration liquid a detected by the acid-base concentration meter is equal to the waste acid concentration entering the weak acid cation bed, the waste acid solution pickling regeneration is stopped by switching the valve, and good acid solution in the acid tank 15 is passed through for pickling regeneration. When the acid concentration of the regeneration liquid a detected by the acid-base concentration meter is equal to the concentration of the good acid solution entering the weak acid cation bed, the good acid solution pickling regeneration is stopped by switching the valve, and the good acid solution in the weak acid cation bed is discharged into the recycled acid tank 17.

[0026] (3) Produced water flushing: The weak acid cation bed at the end of pickling in step (2) is passed through produced water for flushing to flush the residual acid solution in step (2). The drainage of the produced water flushing is discharged into the waste water tank 20 through the upper outlet b of the weak acid cation bed. After the produced water flushing is completed, the produced water in the weak acid cation bed is discharged into the buffer water tank 11.

[0027] (4) Caustic washing regeneration: The weak acid cation exchanger that has completed the water rinsing in step (3) is subjected to caustic washing regeneration by introducing waste caustic solution to form regeneration liquid b. Regeneration liquid b is discharged into waste water tank 20 through upper outlet a. When the caustic concentration meter detects that the caustic concentration of regeneration liquid b is 0.01%, regeneration liquid b is made to enter reuse caustic tank 19 by switching the valve. As the caustic washing regeneration progresses, the caustic concentration meter detects that the caustic concentration of regeneration liquid b gradually increases. When the caustic concentration meter detects that the caustic concentration of regeneration liquid b is equal to the caustic concentration of the waste caustic solution introduced into the weak acid cation exchanger, the caustic washing regeneration with waste caustic solution is stopped by switching the valve, and good caustic solution in caustic tank 13 is introduced for caustic washing regeneration. When the caustic concentration meter detects that the caustic concentration of regeneration liquid b is equal to the concentration of the good caustic solution introduced into the weak acid cation exchanger, the caustic washing regeneration with good caustic solution is stopped by switching the valve, and the good caustic solution in the weak acid cation exchanger is discharged into reuse caustic tank 19;

[0028] (5) Produced water re-rinsing: The weak acid cation exchanger that has completed the caustic washing in step (4) is re-rinsed by introducing produced water to rinse the residual caustic solution in step (4). The drainage from the produced water re-rinsing is discharged into waste water tank 20 through upper outlet b of the weak acid cation exchanger. After the produced water re-rinsing is completed, the produced water in the weak acid cation exchanger is discharged into buffer water tank 11. After the produced water re-rinsing is completed, the weak acid cation exchanger enters the waiting for hardness removal step;

[0029] Each weak acid cation exchanger operates in a cycle according to the sequence of steps (1) to (5). When weak acid cation exchanger a1 is performing step (1), weak acid cation exchanger b2 operates steps (2) to (5). The two weak acid cation exchangers are combined in parallel and operate in a cycle to achieve continuous hardness removal and regeneration.

[0030] The acid solution is a hydrochloric acid solution with a mass concentration of 9%, and the caustic solution is a sodium hydroxide solution with a mass concentration of 9%%; The water in buffer water tank 11 and the high-hardness water are simultaneously fed into the weak acid cation exchanger for hardness removal.

[0031] Four reuse acid tanks and reuse caustic tanks are respectively provided. The four reuse acid tanks are respectively used to collect waste acid solutions with acid concentrations of 0.01% - 1%, 1% - 3%, 3% - 6% and 6% - 9%. The four reuse caustic tanks are respectively used to collect waste caustic solutions with caustic concentrations of 0.01% - 1%, 1% - 3%, 3% - 6% and 6% - 9%. First, the weak acid cation exchanger is regenerated with low-concentration waste acid solution or waste caustic solution, then with high-concentration waste acid solution or waste caustic solution, and finally with good acid solution or good caustic solution, so as to achieve a cascade utilization of waste acid solution or waste caustic solution from low concentration to high concentration, and make the low-concentration waste acid solution or waste caustic solution be converted into waste water as much as possible when regenerating the weak acid cation exchanger.

[0032] When the weak acid cation bed is first put into operation, it is first washed with alkali to replace hydrogen ions with sodium ions, converting the weakly acidic cation exchange resin from the hydrogen form to the sodium form, which is convenient for removing hardness from high-hardness water. When the weak acid cation bed is first put into operation, pickling regeneration is carried out using good acid, and alkali washing regeneration is carried out using good alkali solution. Example 2

[0033] Refer to Figure 2 In Example 2, the difference from Example 1 is as follows: Four recycling acid tanks 17 and recycling alkali tanks are respectively provided. The four recycling acid tanks are respectively used to collect waste acid solutions with acid concentrations of 0.01% - 1%, 1% - 3%, 3% - 5% and 5% - 7%. The four recycling alkali tanks are respectively used to collect waste alkali solutions with alkali concentrations of 0.01% - 1%, 1% - 3%, 3% - 5% and 5% - 7%. First, the weak acid cation bed is regenerated with low-concentration waste acid solution or waste alkali solution, then with high-concentration waste acid solution or waste alkali solution, and finally with good acid solution or good alkali solution, so as to form a cascaded utilization of waste acid solution or waste alkali solution from low concentration to high concentration, and make the low-concentration waste acid solution or waste alkali solution be converted into wastewater as much as possible when regenerating the weak acid cation bed. Three weak acid cation beds are provided, namely weak acid cation bed a1, weak acid cation bed b2, and weak acid cation bed c3. Each weak acid cation bed operates in a cycle according to the sequence of steps (1) to (5). When weak acid cation bed a1 performs step (1), weak acid cation bed b2 performs steps (4) and (5), and weak acid cation bed c3 performs steps (2) and (3). The three weak acid cation beds are combined in parallel and operate in a cycle to achieve continuous hardness removal and regeneration.

[0034] The acid solution is a hydrochloric acid solution with a mass concentration of 7%, and the alkali solution is a sodium hydroxide solution with a mass concentration of 7%. The water in the buffer water tank 11 and the high-hardness water are sent into the weak acid cation bed simultaneously for hardness removal. Example 3

[0035] Refer to Figure 3, the difference between Example 3 and Example 1 is that: three recycling acid tanks 17 and three recycling alkali tanks are respectively provided. The three recycling acid tanks are respectively used to collect waste acid solutions with acid concentrations of 0.01% - 1%, 1% - 3% and 3% - 5%, and the three recycling alkali tanks are respectively used to collect waste alkali solutions with alkali concentrations of 0.01% - 1%, 1% - 3% and 3% - 5%. First, the weak acid cation exchanger is regenerated with low-concentration waste acid solution or waste alkali solution, then the weak acid cation exchanger is regenerated with high-concentration waste acid solution or waste alkali solution, and finally the weak acid cation exchanger is regenerated with good acid solution or good alkali solution, so as to form a cascade utilization of waste acid solution or waste alkali solution from low concentration to high concentration, and make the low-concentration waste acid solution or waste alkali solution be converted into wastewater as much as possible when regenerating the weak acid cation exchanger; five weak acid cation exchangers are provided, namely weak acid cation exchanger a1, weak acid cation exchanger b2, weak acid cation exchanger c3, weak acid cation exchanger d4, and weak acid cation exchanger e5. Each weak acid cation exchanger operates in a cycle according to the sequence of steps (1) to (5). When weak acid cation exchanger a1 performs step (1), weak acid cation exchanger b2 operates step (5), weak acid cation exchanger c3 operates step (4), weak acid cation exchanger d4 operates step (3), and weak acid cation exchanger e5 operates step (2). The five weak acid cation exchangers are combined in parallel and operate in a cycle to achieve continuous hardness removal and regeneration.

[0036] The acid solution is a hydrochloric acid solution with a mass concentration of 5%, and the alkali solution is a sodium hydroxide solution with a mass concentration of 5%; the water in the buffer water tank 11 and the high-hardness water are sent into the weak acid cation exchanger for hardness removal at the same time. Example 4

[0037] Refer to Figure 4 , the difference between Example 4 and Example 1 is that: two recycling acid tanks 17 and two recycling alkali tanks are respectively provided. The two recycling acid tanks are respectively used to collect waste acid solutions with acid concentrations of 0.01% - 1% and 1% - 3%, and the two recycling alkali tanks are respectively used to collect waste alkali solutions with alkali concentrations of 0.01% - 1% and 1% - 3%. First, the weak acid cation exchanger is regenerated with low-concentration waste acid solution or waste alkali solution, then the weak acid cation exchanger is regenerated with high-concentration waste acid solution or waste alkali solution, and finally the weak acid cation exchanger is regenerated with good acid solution or good alkali solution, so as to form a cascade utilization of waste acid solution or waste alkali solution from low concentration to high concentration, and make the low-concentration waste acid solution or waste alkali solution be converted into wastewater as much as possible when regenerating the weak acid cation exchanger; six weak acid cation exchangers are provided, namely weak acid cation exchanger a1, weak acid cation exchanger b2, weak acid cation exchanger c3, weak acid cation exchanger d4, weak acid cation exchanger e5, and weak acid cation exchanger f6. Each weak acid cation exchanger operates in a cycle according to the sequence of steps (1) to (5). When weak acid cation exchanger a1 performs step (1), weak acid cation exchanger b2 waits to perform step (1), weak acid cation exchanger c3 operates step (5), weak acid cation exchanger d4 operates step (4), weak acid cation exchanger e5 operates step (3), and weak acid cation exchanger f6 operates step (2). The six weak acid cation exchangers are combined in parallel and operate in a cycle to achieve continuous hardness removal and regeneration.

[0038] The acid solution is a hydrochloric acid solution with a mass concentration of 3%, and the alkali solution is a sodium hydroxide solution with a mass concentration of 3%; the water in the buffer water tank 11 and the high-hardness water are simultaneously fed into the weak acid cation exchanger for hardness removal. Example 5

[0039] Refer to Figure 4 Example 5 is different from Example 1 in that: two recycling acid tanks 17 and two recycling alkali tanks are respectively provided. The two recycling acid tanks are respectively used to collect waste acid solutions with acid concentrations of 0.01% - 1% and 1% - 3%, and the two recycling alkali tanks are respectively used to collect waste alkali solutions with alkali concentrations of 0.01% - 1% and 1% - 3%. First, the weak acid cation exchanger is regenerated with low-concentration waste acid solution or waste alkali solution, then with high-concentration waste acid solution or waste alkali solution, and finally with good acid solution or good alkali solution, so as to form a stepped utilization of waste acid solution or waste alkali solution from low concentration to high concentration, and make the low-concentration waste acid solution or waste alkali solution be converted into wastewater as much as possible when regenerating the weak acid cation exchanger; six weak acid cation exchangers are provided, namely weak acid cation exchanger a1, weak acid cation exchanger b2, weak acid cation exchanger c3, weak acid cation exchanger d4, weak acid cation exchanger e5, and weak acid cation exchanger f6. Each weak acid cation exchanger operates in a cycle according to the order of steps (1) to (5). When weak acid cation exchanger a1 performs step (1), weak acid cation exchanger b2 delays running step (1) for a certain time, weak acid cation exchanger c3 runs step (5), weak acid cation exchanger d4 runs step (4), weak acid cation exchanger e5 runs step (3), and weak acid cation exchanger f6 runs step (2). In this example, two weak acid cation exchangers perform step (1) at the same time, and the six weak acid cation exchangers are combined in parallel and operate in a cycle to achieve continuous hardness removal and regeneration.

[0040] The acid solution is a hydrochloric acid solution with a mass concentration of 3%, and the alkali solution is a sodium hydroxide solution with a mass concentration of 3%; the water in the buffer water tank 11 and the high-hardness water are simultaneously fed into the weak acid cation exchanger for hardness removal.

[0041] Each weak acid cation exchanger in the present utility model operates in a cycle according to the steps of hardness removal, pickling regeneration, product water flushing, caustic washing regeneration, and product water re-flushing. The number of weak acid cation exchangers is reasonably set according to the running time of each step. More units are set for the steps with longer running time, and fewer units are set for the steps with shorter running time. By reasonably matching the number of weak acid cation exchangers in each running step, the optimal running effect is achieved.

[0042] In order to more clearly express the technical solution of the present utility model, many stop valves are drawn in the specification drawings. The technical solution protected by the applicant is not limited to stop valves, and any valve that can implement the technical solution of the present utility model is acceptable.

[0043] Working principle of the present utility model: The present utility model realizes continuous hard removal and regeneration by arranging two or more weak acid cation exchangers in parallel, and each weak acid cation exchanger operates staggeredly in time according to steps (1) to (5). The waste acid and waste alkali generated during the regeneration process of the cation exchanger are used for waste acid washing or waste alkali washing of the weak acid cation exchanger, and then good acid solution and good alkali solution are used for regeneration, so that the waste acid solution and waste alkali solution are fully utilized, and at the same time, the consumption of good acid solution and good alkali solution is reduced; the present utility model greatly reduces the consumption of acid solution and alkali solution during the hard removal process of high-hardness water, and at the same time effectively utilizes the waste acid resources and waste alkali resources, avoiding the waste of acid resources and alkali resources caused by the neutralization of waste acid solution and waste alkali solution.

[0044] Modifications and changes to this creation by those familiar with the present utility model fall within the scope of the patent of the present utility model, not limited to those described in the embodiments.

Claims

1. A device for continuous hardness removal and regeneration of a weak acid cation bed, characterized in that: It includes weak acid cation beds, acid tanks, alkali tanks, recycled acid tanks, recycled alkali tanks, and wastewater tanks. Two or more weak acid cation beds are provided, and two or more weak acid cation beds are connected in parallel. The upper water inlet of each weak acid cation bed is connected to the incoming water pipeline through a pipeline. The bottom inlet and outlet of each weak acid cation bed are connected to the inlet of the product water tank through a pipeline. The outlet of the product water tank is connected to the bottom inlet and outlet of each weak acid cation bed through a product water pump. The outlet of the product water pump is also connected to the downstream device through pipeline a; the bottom inlet and outlet of each weak acid cation bed are communicated with the acid tank through an acid pipeline, and the bottom inlet and outlet of each weak acid cation bed are communicated with the alkali tank through an alkali pipeline. Each weak acid cation bed is provided with two upper outlets and one middle outlet. The two upper outlets are respectively upper outlet a and upper outlet b. Upper outlet a and the middle outlet are respectively communicated with the recycled acid tank, the recycled alkali tank, and the wastewater tank through pipelines. Upper outlet b is communicated with the wastewater tank through a pipeline; the recycled acid tank is communicated with the bottom inlet and outlet of the weak acid cation bed through a pipeline and a recycled acid pump, and the recycled alkali tank is communicated with the bottom inlet and outlet of the weak acid cation bed through a pipeline and a recycled alkali pump; the bottom inlet and outlet of the weak acid cation bed are also communicated with the inlet of the buffer water tank through a pipeline, and the outlet of the buffer water tank is connected to the incoming water pipeline through a buffer water pump; the wastewater tank is connected to the downstream wastewater treatment device through a wastewater pump and a wastewater pipeline.

2. The device for continuously removing hardness and regenerating a weak acid cation bed according to claim 1, wherein: Acid pumps and alkali pumps are respectively arranged on the pipelines connecting the weak acid cation beds with the acid tank and the alkali tank.

3. The device for continuous hardness removal and regeneration of a weak acid cation bed according to claim 1, characterized in that: Acid-base concentration meters are arranged on the pipelines connecting upper outlet a, upper outlet b and the middle outlet of each weak acid cation bed; acid-base concentration meters are arranged on the pipelines connecting the bottom inlet and outlet of the weak acid cation bed with the recycled acid tank and the recycled alkali tank; acid-base concentration meters are arranged on both the acid pipeline and the alkali pipeline.

4. A device for continuous hardness removal and regeneration of a weak acid cation bed according to claim 1, characterized in that: The weak acid cation bed is provided with a liquid level detection device.

5. The device for continuous hardness removal and regeneration of a weak acid cation bed according to claim 1, characterized in that: An air suction and exhaust port is arranged at the top of the weak acid cation bed.

6. The device for continuous hard removal and regeneration of a weak acid cation bed according to claim 1, characterized in that: One or more recycled acid tanks and one or more recycled alkali tanks are provided, which respectively collect waste acid liquid and waste alkali liquid with different concentrations.

7. A device for continuous hardness removal and regeneration of a weak acid cation bed according to any one of claims 1-6, characterized in that: It also includes an automatic control device, and the automatic control device is connected to the device for continuous hard removal and regeneration of the weak acid cation bed.

Images