A water-saving and safe ion exchange regeneration device and method and wastewater recovery process

Abstract

The present invention provides a water-saving and safe ion exchange regeneration device and method and a wastewater recovery process, including a water inlet pipe, an ion exchanger, an alkali inlet pipe, an acid inlet pipe, a compressed air inlet pipe, and a water production pipe; the water inlet pipe is connected to the top of the ion exchanger, and one end of the alkali inlet pipe is connected to the top of the ion exchanger through the water inlet pipe; the other end of the alkali inlet pipe is connected to the alkali source; the water production pipe is arranged at the bottom of the ion exchanger, and one end of the acid inlet pipe and the compressed air inlet pipe are both connected to the water production pipe; the other end of the acid inlet pipe is connected to the acid source, and the other end of the compressed air inlet pipe is connected to the compressed air source. The water-saving and safe ion exchange regeneration device and method and wastewater recovery process described in the present invention have a wide range of applications. The patent can be used for the regeneration process of different ion exchange equipment to collect the backwash wastewater, acid-base wastewater, displacement wastewater, forward wash wastewater and other parts with better water quality, and the typical one-time recovery rate is ≥90%.

Description

Technical Field

[0001] The invention belongs to the field of ion exchanger regeneration and wastewater recovery in chemical, petrochemical, thermal power and other industries, and in particular relates to a water-saving and safe ion exchange regeneration device and method and a wastewater recovery process. Background Art

[0002] When regenerating a traditional mixed ion exchanger, all wastewater is discharged into the ditch by gravity flow, and other wastewater is collected through the ditch and sent to the sewage treatment device or zero-discharge device for unified treatment, resulting in a more complex composition of the wastewater. The scale of the treatment facilities for this wastewater is too large and the energy consumption is high.

[0003] The acid and alkaline wastewater generated during the backwashing and regeneration process is discharged into underground facilities such as ditches and pools, posing a high risk of groundwater pollution.

[0004] Traditional ion exchangers have the risk of acid and alkali leakage during normal operation, which affects the water quality. Acids and alkalis are corrosive and also bring certain safety risks.

[0005] The traditional process will mix the ion exchange wastewater with other wastewaters, and only after being treated by regulating tanks, biochemical tanks, high-density sedimentation tanks, V-type filters, ozone catalytic oxidation tanks and other devices can it enter the ultrafiltration front-end filtration system for filtration, desalination and recovery. The process is long and the disposal process is complicated. The design scale of each water treatment device is large, and after mixing with other wastewaters, the treatment effect of this wastewater is deteriorated, and the water quality of the recycled water is affected. Summary of the invention

[0006] In view of this, the present invention aims to propose a water-saving and safe ion exchange regeneration device and method and a wastewater recovery process to solve the problem.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A water-saving and safe ion exchange regeneration device comprises a water inlet pipeline, an ion exchanger, an alkali inlet pipeline, an acid inlet pipeline, a compressed air inlet pipeline, and a water production pipeline;

[0009] The water inlet pipe is connected to the top of the ion exchanger, one end of the alkali inlet pipe is connected to the top of the ion exchanger through the water inlet pipe; the other end of the alkali inlet pipe is connected to the alkali source;

[0010] The water production pipeline is arranged at the bottom of the ion exchanger, and one end of the acid inlet pipeline and the compressed air inlet pipeline are connected to the water production pipeline; the other end of the acid inlet pipeline is connected to the acid source, and the other end of the compressed air inlet pipeline is connected to the compressed air source.

[0011] Furthermore, the water inlet pipe is provided with a backwash water inlet pipe and a backwash water outlet pipe, the backwash water inlet pipe is connected to the water production pipe, and the backwash water outlet pipe is connected to the wastewater recovery pipe;

[0012] The wastewater recovery pipeline is connected to other wastewater recovery pipelines of the same type of ion exchangers, a conductivity analyzer is provided on the wastewater recovery pipeline through a discharge pipeline, and a wastewater discharge valve is provided on the discharge pipeline;

[0013] Furthermore, the top of the ion exchanger is provided with an upper pipe, and the upper pipe is provided with an upper water discharge valve.

[0014] The water production pipeline is provided with a down-drain pipeline, a drain pipeline, a first resin catcher, a positive wash drainage pipeline, and a water production valve in sequence;

[0015] The down-discharge pipe is arranged between the acid inlet pipe and the compressed air inlet pipe, and a down-discharge valve is arranged on the down-discharge pipe; the drain pipe is arranged between the compressed air inlet pipe and the first backwash water inlet pipe, and a drain valve is arranged on the drain pipe.

[0016] One end of the forward wash drainage pipe is arranged on the water production pipe, and the other end of the forward wash drainage pipe is arranged on the backwash outlet pipe;

[0017] A positive wash drainage valve is provided on the positive wash drainage pipeline.

[0018] Furthermore, the water inlet pipe is provided with a water inlet valve, and the water inlet valve is arranged between the backwash water inlet pipe and the backwash water outlet pipe;

[0019] A backwash water inlet valve is arranged on the backwash water inlet pipe, and a backwash water outlet valve is arranged on the backwash water outlet pipe.

[0020] Furthermore, a middle row of pipes is provided in the middle of the ion exchanger, and a middle row of valves and a second resin trap are provided on the middle row of pipes in sequence, and the second resin trap is arranged on a side away from the ion exchanger.

[0021] Furthermore, a first acid inlet valve is provided on the acid inlet pipeline, a first pipeline and a second pipeline are connected in parallel on the acid inlet pipeline, the other end of the first pipeline is connected to the water production pipeline, a second acid inlet valve is provided on the first pipeline, and a third acid inlet valve is provided on the second pipeline.

[0022] Furthermore, the alkali inlet pipeline is provided with a first alkali inlet valve, the alkali inlet pipeline is connected with a third pipeline and a fourth pipeline, and the other end of the fourth pipeline is connected with the water inlet pipeline.

[0023] The fourth pipeline is provided with a second alkali inlet valve, and the third pipeline is provided with a third alkali inlet valve.

[0024] Preferably, a plurality of evenly distributed sight glasses are provided on the ion exchanger.

[0025] The ion exchange process is to place the exchange agent (resin) in the ion exchanger (or bed) and restore the ion exchange capacity by regeneration after the ion exchange agent fails. In order to improve the economy and technical applicability of the ion exchange process, different resin combinations, different bed types and various ion exchange systems have been produced.

[0026] This patent proposes a new type of water-saving and safe ion exchange regeneration method and wastewater recovery process, which is particularly suitable for factories with both desalinated water devices and zero emission devices. The regeneration method is applicable to a variety of ion exchange systems, including strong / weak anion, cation and mixed ion exchange systems.

[0027] When the ion exchanger is undergoing acid-base regeneration, the wastewater produced only contains high salt content (TDS, mainly sodium chloride or sodium sulfate), and other impurities (such as COD, turbidity, etc.) are very low. In addition, the regeneration wastewater of the ion exchanger used for condensate refining will also have high ammonia nitrogen. If this part of the regeneration wastewater is collected, it needs to be pre-treated to remove part of the ammonia nitrogen.

[0028] The regenerated wastewater from the ion exchanger has a certain residual pressure and can enter a separate wastewater collection tank for direct use in other devices.

[0029] This patent is aimed at the recycling of regenerated wastewater and proposes a process method that can safely and stably recycle regenerated wastewater. The function of recycling wastewater can be realized through program control. At the same time, by setting up a three-valve group, the risk of acid and alkali valves leaking during normal operation and regeneration, causing acids and alkalis to enter the ion exchange system, is eliminated.

[0030] This patent eliminates the water discharge step before adding acid and alkali in the sequence, and uses the residual pressure of the acid, alkali and replacement water pumped in by the regeneration pump to effectively collect the acid and alkali wastewater and replacement wastewater. The backwash wastewater and forward wash wastewater generated in the other steps have residual pressure themselves. By setting up a recovery main pipe, the residual pressure wastewater is collected. In order to ensure that the recycled wastewater does not contain resin impurities, a resin catcher B is added to the middle discharge pipeline. At the end of regeneration, the regeneration effect is determined by measuring the conductivity of the forward wash water. For the case of multiple systems in parallel, a conductivity analyzer is designed on the recovery wastewater main pipe to analyze the regeneration effect of all ion exchangers of the same type.

[0031] At the same time, two pneumatic valves are added to the acid and alkali inlet pipelines. During normal operation, even if the acid and alkali valves leak, they will not enter the ion exchanger, ensuring the stability of the system's water production.

[0032] A water-saving and safe ion exchange regeneration method comprises the following steps:

[0033] S1: Incoming water enters the ion exchanger through the water inlet pipe, and the water produced by the ion exchanger enters the downstream storage tank through the first resin trap on the water production pipe;

[0034] S2: Forward wash, the incoming water enters the wastewater recovery pipe through the water inlet pipe and the forward wash drainage pipe. The conductivity analyzer on the wastewater recovery pipe measures the conductivity of the produced water; the duration is 10-20 minutes;

[0035] S3: Backwash stratification, the incoming water enters the ion exchanger through the water inlet pipe and the first backwash water inlet pipe, and the ion exchanger backwash water is recycled through the water inlet pipe, the backwash water outlet pipe, and the recycled wastewater pipe in turn; the duration is 10-20 minutes;

[0036] S4: Alkali enters the ion exchanger from the top through the alkali inlet pipe and the water inlet pipe. At the same time, acid enters the ion exchanger from the bottom through the acid inlet pipe. The acid reacts with the cation resin. H + The cations adsorbed by the cation resin are replaced, and the base reacts with the anion resin to form OH - The other anions in the anion resin are replaced, and the acid and alkali after the reaction are recovered as neutralized wastewater through the middle discharge pipe and the wastewater recovery pipe, and the duration is 30-60 minutes;

[0037] S5: Replacement, the excess acid and alkali need to be replaced with water, the duration is 60-90 minutes;

[0038] S6: Compressed air mixed with fat is introduced. The compressed air enters the ion exchanger from the bottom through the compressed air inlet pipe and is discharged through the upper pipe. The duration is 0.5-1min.

[0039] S7: Gravity flow discharge, the upper valve on the upper pipe is opened, and the water is discharged into the ditch through the lower pipe by gravity flow, and the duration is 1-10 minutes.

[0040] Furthermore, in the step S4, the first alkali inlet valve, the second alkali inlet valve, and the third alkali inlet valve are in an open state, and in the step S4, the first acid inlet valve, the second acid inlet valve, and the third acid inlet valve are in an open state.

[0041] In the steps S1, S2 and S3, the first alkali inlet valve and the second alkali inlet valve are in a closed state, and the third alkali inlet valve is in an open state; in the steps S1, S2 and S3, the first acid inlet valve and the second acid inlet valve are in a closed state, and the third acid inlet valve is in an open state.

[0042] According to the water quality characteristics of the recycled wastewater, this patent directly collects it into the ultrafiltration front end of the zero-emission system (pretreatment is required to remove ammonia nitrogen when the ammonia nitrogen is too high). After being treated by the ultrafiltration device, weak acid cationic bed, and reverse osmosis device of the zero-emission system, the produced water is directly reused to the front end of the cationic bed, and desalted water is prepared for secondary treatment. The concentrated water enters the downstream for further treatment. According to this process, the comprehensive wastewater recovery rate can reach 61.75%, and the salt in the neutralized wastewater can be effectively recovered and neutralized for secondary use.

[0043] The specific process flow of recycled wastewater recovery is as follows: Figure 2 (Among them, strong acid cation bed, strong base anion bed, mixed bed, weak acid cation bed, etc. can refer to the attached Figure 1 Regeneration method for wastewater collection):

[0044] The traditional process will mix the ion exchange wastewater with other wastewaters, and only after being treated by regulating tanks, biochemical tanks, high-density sedimentation tanks, V-type filters, ozone catalytic oxidation tanks and other devices can it enter the ultrafiltration front-end filtration system for filtration, desalination and recovery. The process is long and the disposal process is complicated. The design scale of each water treatment device is large, and after mixing with other wastewaters, the treatment effect of this wastewater is deteriorated, and the water quality of the recycled water is affected.

[0045] Compared with the traditional process flow, the ion exchange wastewater recovery process proposed in this patent reduces some water treatment equipment. The process flow is short, highly targeted, the recycled water has good water quality and good treatment effect. It is a new process method for recovering high-quality ion exchange wastewater.

[0046] A wastewater recovery process for a water-saving and safe ion exchange regeneration device comprises the following steps:

[0047] S1: Fresh water used to prepare demineralized water first enters the pre-treatment filter device;

[0048] S2: Fresh water after filtration passes through a strong acid cation bed to remove cations in the water, and the acidic water enters a denitrification tower to remove the generated carbon dioxide;

[0049] S3: After decarbonization, the anions in the water are removed by a strong alkaline anion bed, and the produced water enters the mixed bed for secondary refining. The prepared deionized water can be used externally;

[0050] S4: The regeneration system includes an acid system and an alkali system. The time of adding acid and alkali in the step is adjusted to control the wastewater generated by the synchronous regeneration of the yin and yang beds and the recycled wastewater generated by the mixed bed regeneration to be neutral. The pH value of the wastewater is monitored after mixing, and acid and alkali are added to ensure that the wastewater remains neutral;

[0051] S5: Recycle wastewater into the pretreatment device to remove excess ammonia nitrogen in the water;

[0052] S6: The pretreated wastewater enters the zero-emission ultrafiltration, weak acid cation bed, and reverse osmosis device for treatment. Part of the regenerated wastewater from the weak acid cation bed can be recycled and mixed with the recycled wastewater from the cation bed, anion bed, and mixed bed, and then recycled as high-quality wastewater.

[0053] The difference is that the backwash wastewater and acid inlet wastewater of the weak acid cation bed contain more divalent scaling cations (calcium and magnesium ions), which can be directly discharged into the ditch and mixed with other wastewater for post-treatment. The replacement wastewater and forward wash wastewater of the weak acid cation bed have better water quality and can be recycled according to the wastewater recycling process proposed in this patent.

[0054] S7: The water produced by the reverse osmosis of the zero-emission device is recycled to the front end of the strong acid cation bed for secondary utilization, and the reverse osmosis concentrated water is discharged to the downstream for further treatment, and industrial salt is prepared by the subsequent evaporation and crystallization device.

[0055] Strong acid cation bed, strong base anion bed, mixed bed and weak acid cation bed are the steps of ion exchange in this process. Figure 1 Targeted recycling of regenerated wastewater. If there are other ion exchange equipment in the system, the high-quality wastewater produced by it can also be recycled according to the recycling method proposed in this process and treated after mixing.

[0056] Compared with the prior art, the water-saving and safe ion exchange regeneration device and method and wastewater recovery process described in the present invention have the following beneficial effects:

[0057] 1. This patent proposes a water-saving and safe ion exchange regeneration method based on the water quality characteristics of recycled wastewater. It has a wide range of applications and can collect the backwash wastewater, acid-base wastewater, replacement wastewater, forward wash wastewater and other parts with better water quality during the regeneration process of different ion exchange equipment. The typical one-time recovery rate is ≥90%.

[0058] 2. This patent directly collects the ion exchange recovery wastewater inside the system into the ultrafiltration front end of the zero-emission system. After being treated by the ultrafiltration device, weak acid cationic bed, reverse osmosis device, etc. of the zero-emission system (recovery rate ≥ 65%), the produced water is directly reused to the front end of the cationic bed for secondary preparation of demineralized water, and the concentrated water enters the downstream for further treatment. The comprehensive wastewater recovery rate can reach 61.75%.

[0059] 3. This patent shortens the process flow of treating the regenerated wastewater, reduces the operating cost and energy consumption of treating the wastewater, and regenerated wastewater is recycled for the second time as the influent of the desalted water system for preparing desalted water; concentrated water enters the downstream evaporation and crystallization device for preparing industrial salt.

[0060] 4. The collected high-quality wastewater is treated specifically for reuse. Compared with the traditional treatment of mixed wastewater, the wastewater treatment effect is good and the recycled water quality is excellent. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0062] Figure 1 A schematic diagram of a water-saving and safe ion exchange regeneration device according to an embodiment of the present invention;

[0063] Figure 2 This is a schematic diagram of Example 1 of a water-saving and safe ion exchange regeneration device according to an embodiment of the present invention;

[0064] Figure 3 This is a schematic diagram of a water-saving and safe ion exchange regeneration method described in an embodiment of the present invention.

[0065] Description of reference numerals:

[0066] 1. First alkali inlet valve; 2. Second alkali inlet valve; 3. Third alkali inlet valve; 4. Water inlet valve; 5. Backwash outlet valve; 6. Upper row valve; 7. Backwash inlet valve; 8. Forward wash water valve; 9. First acid inlet valve; 10. Second acid inlet valve; 11. Third acid inlet valve; 12. Compressed air inlet valve; 13. Water production valve; 14. Lower row valve; 15. First resin trap; 16. Second resin trap; 17. Sight glass; 18. Middle row valve; 19. Conductivity analyzer; 2 0. Wastewater discharge valve; L001. Water inlet pipe; L002. Water production pipe; L003. Wastewater recovery pipe; L101. Backwash water inlet pipe; L102. Backwash water outlet pipe; L201. Alkali inlet pipe; L202. Acid inlet pipe; L203. Middle row pipe; L301. Compressed air inlet pipe; L401. Forward wash drainage pipe; L501. Upper row pipe; L502. Lower row pipe; L601. Drain pipe; L901. Wastewater recovery pipe of other ion exchangers of the same type. DETAILED DESCRIPTION

[0067] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0068] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0069] Embodiment 1:

[0070] A water-saving and safe ion exchange regeneration device comprises a water inlet pipeline L001, an ion exchanger, an alkali inlet pipeline L201, an acid inlet pipeline L202, a compressed air inlet pipeline L301, and a water production pipeline L002; the water inlet pipeline L001 is connected to the top of the ion exchanger, and one end of the alkali inlet pipeline L201 is connected to the top of the ion exchanger through the water inlet pipeline L001; the other end of the alkali inlet pipeline L201 is connected to an alkali source; the water production pipeline L002 is arranged at the bottom of the ion exchanger, and one end of the acid inlet pipeline L202 and the compressed air inlet pipeline L301 are both connected to the water production pipeline L002; the other end of the acid inlet pipeline L202 is connected to the acid source, and the other end of the compressed air inlet pipeline L301 is connected to the compressed air source. The water inlet pipe L001 is provided with a backwash water inlet pipe L101 and a backwash water outlet pipe L102, the backwash water inlet pipe L101 is connected to the water production pipe L002, and the backwash water outlet pipe L102 is connected to the recovery wastewater pipe L003; the recovery wastewater pipe L003 is connected to other ion exchanger recovery wastewater pipes L901 of the same type, and the recovery wastewater pipe L003 is provided with a conductivity analyzer 19 through a discharge pipe, and a wastewater discharge valve 20 is provided on the discharge pipe; it also includes that an upper row pipe L501 is provided on the top of the ion exchanger, and the upper row pipe L501 is provided with an upper drainage valve. The water production pipeline L002 is provided with a downpipe L502, a drain pipeline L601, a first resin catcher 15, a forward wash drainage pipeline L401, and a water production valve 13 in sequence; the downpipe L502 is arranged between the acid inlet pipeline L202 and the compressed air inlet pipeline L301, and a downpipe valve 14 is provided on the downpipe L502; the drain pipeline L601 is arranged between the compressed air inlet pipeline L301 and the first backwash water inlet pipeline L101, and a drain valve is provided on the drain pipeline L601.

[0071] One end of the forward wash drainage pipe L401 is arranged on the water production pipe L002, and the other end of the forward wash drainage pipe L401 is arranged on the backwash outlet pipe L102; a forward wash drainage valve is arranged on the forward wash drainage pipe L401. A water inlet valve 4 is arranged on the water inlet pipe L001, and the water inlet valve 4 is arranged between the backwash water inlet pipe L101 and the backwash outlet pipe L102; a backwash water inlet valve 74 is arranged on the backwash water inlet pipe L101, and a backwash outlet valve 5 is arranged on the backwash outlet pipe L102. A middle row pipe L203 is arranged in the middle of the ion exchanger, and a middle row valve 18 and a second resin trap 16 are arranged in sequence on the middle row pipe L203, and the second resin trap 16 is arranged on the side away from the ion exchanger. The acid inlet pipeline L202 is provided with a first acid inlet valve 9, the acid inlet pipeline L202 is connected with a first pipeline and a second pipeline in parallel, the other end of the first pipeline is connected to the water production pipeline L002, the first pipeline is provided with a second acid inlet valve 10, and the second pipeline is provided with a third acid inlet valve 11. The alkali inlet pipeline L201 is provided with a first alkali inlet valve 1, the alkali inlet pipeline L201 is connected with a third pipeline and a fourth pipeline in parallel, the other end of the fourth pipeline is connected to the water inlet pipeline L001, the fourth pipeline is provided with a second alkali inlet valve 2, and the third pipeline is provided with a third alkali inlet valve 3. Preferably, the ion exchanger is provided with a plurality of evenly distributed sight glasses 17.

[0072] The ion exchange process is to place the exchange agent (resin) in the ion exchanger (or bed) and restore the ion exchange capacity by regeneration after the ion exchange agent fails. In order to improve the economy and technical applicability of the ion exchange process, different resin combinations, different bed types and various ion exchange systems have been produced.

[0073] This patent proposes a new type of water-saving and safe ion exchange regeneration method and wastewater recovery process, which is particularly suitable for factories with both desalinated water devices and zero emission devices. The regeneration method is applicable to a variety of ion exchange systems, including strong / weak anion, cation and mixed ion exchange systems.

[0074] When the ion exchanger is undergoing acid-base regeneration, the wastewater produced only contains high salt content (TDS, mainly sodium chloride or sodium sulfate), and other impurities (such as COD, turbidity, etc.) are very low. In addition, the regeneration wastewater of the ion exchanger used for condensate refining will also have high ammonia nitrogen. If this part of the regeneration wastewater is collected, it needs to be pre-treated to remove part of the ammonia nitrogen.

[0075] The regenerated wastewater from the ion exchanger has a certain residual pressure and can enter a separate wastewater collection tank for direct use in other devices.

[0076] This patent is aimed at the recycling of regenerated wastewater and proposes a process method that can safely and stably recycle regenerated wastewater. The function of recycling wastewater can be realized through program control. At the same time, by setting up a three-valve group, the risk of acid and alkali valves leaking during normal operation and regeneration, causing acids and alkalis to enter the ion exchange system, is eliminated.

[0077] This patent eliminates the water discharge step before adding acid and alkali in the sequence, and utilizes the residual pressure of the acid, alkali and replacement water pumped in by the regeneration pump to effectively collect the acid and alkali wastewater and replacement wastewater. The backwash wastewater and forward wash wastewater generated in the other steps have residual pressure themselves. By setting up a recovery main pipe, the residual pressure wastewater is collected. In order to ensure that the recycled wastewater does not contain resin impurities, a resin catcher B is added to the middle row pipeline. At the end of regeneration, the regeneration effect is determined by measuring the conductivity of the forward wash water. For the case of multiple systems in parallel, a conductivity analyzer 19 is designed on the recovery wastewater main pipe to analyze the regeneration effect of all ion exchangers of the same type.

[0078] At the same time, two pneumatic valves are added to the acid and alkali inlet pipelines. During normal operation, even if the acid and alkali valves leak, they will not enter the ion exchanger, ensuring the stability of the system's water production. The main steps of the ion exchange regeneration method are as follows: Figure 2 As shown:

[0079] During normal operation, the incoming water enters the ion exchanger through L001, and the water produced by the ion exchanger enters the downstream storage tank through L002. L002 is provided with a resin trap A, as shown in step 4.

[0080] In the positive wash, water enters the ion exchanger through L001, and the water produced by the ion exchanger is recycled as waste water through L401-L003. L003 is equipped with a conductivity analyzer, which can measure the conductivity of the produced water through conductivity AT-80 to ensure that the ion exchanger meets the design requirements, such as steps 3, 10, 15, etc., and the duration is 10 to 20 minutes.

[0081] Backwash stratification, water enters the ion exchanger through L001-L101, and the ion exchanger backwash water is recovered as waste water through L001-L102-L003, as shown in step 6, lasting 10-20 minutes.

[0082] Acid and alkali are introduced, and the alkali enters the ion exchanger from the top through L201. At the same time, the acid enters the ion exchanger from the bottom through L202. The acid reacts with the cation resin, and H+ displaces other cations adsorbed by the cation resin. The alkali reacts with the anion resin, and OH- displaces other anions adsorbed by the anion resin. The acid and alkali after the reaction are completed are recovered as neutralization wastewater through the middle row pipe L203-L003. L203 is equipped with a resin collector B, as shown in step 8, and the duration is 30-60 minutes.

[0083] Replacement: Excessive acid and alkali need to be replaced with water, such as step 9, lasting 60-90 minutes.

[0084] Compressed air mixed with fat is introduced, and the compressed air enters the ion exchanger from the bottom through L301 and is discharged through L501, as shown in step 12, and the duration is 0.5-1min.

[0085] Gravity flow discharge, the pneumatic valve of L501 pipeline is opened, and the water is discharged into the ditch through L502 gravity flow. This part of water is not collected, such as steps 11 and 13, and the duration is 1-10 minutes

[0086] KV-90F1 / F2 / F3 and KV-90E1 / E2 / E3 are in action only during regeneration. During normal operation, KV-90F1 / F2 and KV-90E1 / E2 are kept in the closed state, and KV-90F3 and KV-90E3 are kept in the open state.

[0087] The main process pipelines and pneumatic valves set up in this patent are shown in the following table:

[0088]

[0089]

[0090] Example 2. Water saving rate calculation example

[0091] The mixed ion exchanger has a water inlet of 240m3 / h. There are 3 units in total, 2 in use and 1 as a spare. The diameter of each unit is 3000mm.

[0092] The regeneration sequence of the ion exchanger designed in the present invention is summarized and calculated, and the total regeneration sequence and time (the time is adjustable, the following data is for example) are as follows:

[0093] (1) Backwash v = 10 m / h, t = 15 min

[0094] Backwash water consumption V1 = 0.785 × 3 × 3 × 10 × 15 / 60 = 17.6m 3

[0095] (2) Regeneration of cationic resin

[0096] The regeneration acid used was 4% HCl, v = 4m / h, t = 56min

[0097] Dilute acid consumption V2 = 0.785 × 3 × 3 × 4 × 56 / 60 = 26.4m 3

[0098] To ensure the consistency of acid-base time, the 4-minute differential water volume V6 = 0.785 × 3 × 3 × 4 × 4 / 60 = 1.9 m 3

[0099] (3) Anion resin regeneration

[0100] The regeneration alkali uses 4% NaOH, v = 4m / h, t = 60min

[0101] Consumption of diluted alkali V3 = 0.785 × 3 × 3 × 4 × 60 / 60 = 28.3m 3

[0102] (4) Replacement

[0103] v=4m / h,t=75min

[0104] Water consumption V4 = 0.785 × 3 × 3 × 4 × 2 × 75 / 60 ​​= 70.7m 3

[0105] (5) Gas mixing

[0106] Use 0.15MPa compressed air for fat mixing, air volume 2.5Nm 3 / m 2 .min, mixing time 1min

[0107] (6) Washing

[0108] v=25m / h,t=10min

[0109] Water consumption V5 = 0.785 × 3 × 3 × 25 × 10 / 60 = 29.5m 3

[0110] (7) Gravity flow displacement

[0111] Each regeneration gravity flow needs to be drained twice, and the total drainage level is about 1 meter. Calculate the drainage volume:

[0112] V7=0.785×3×3×1=7.1m 3

[0113] (8) Total water volume

[0114] Total amount of wastewater produced V8 = V1 + V2 + V3 + V4 + V5 + V6 + V7 = 17.6 + 26.4 + 28.3 + 70.7 + 29.5 + 1.9 + 7.1 = 181.5m 3

[0115] Total amount of wastewater recovered: V9 = 181.5-7.1 = 174.4m 3

[0116] Wastewater recovery rate: 174.4 / 181.5=96.1%

[0117] It can be concluded from the above calculation that, typically, the wastewater recovery rate of the ion exchanger proposed in the present invention is 96.1%.

[0118] When a common mixed ion exchanger is regenerated, gravity flow drainage is one more time than that proposed in this patent, and the water volume is about 0.5*V7=3.6m 3 Therefore, the total amount of wastewater discharged from the common mixed ion exchanger is (181.5+3.6=184.1m 3 ), all these wastewaters are discharged into the ditch, which collects other sewage and enters the sewage treatment plant or zero-discharge device for unified treatment.

[0119] This method proposes that the high-quality wastewater (174.4 mm 3 ) are collected and combined with other high-quality wastewater from ion exchange to be treated as a high-quality wastewater source. Compared with ordinary ion exchangers, the wastewater recovery rate is: 174.4 / 184.1=94.7%.

[0120] Embodiment 3:

[0121] Table 1

[0122]

[0123] Comparative Example 1

[0124] Table 2

[0125]

[0126] The above K represents that the valve is open, and G represents that the valve is closed.

[0127] Comparing Appendix 1 and Appendix 2 of Example 2, the main differences between the conventional ion exchange and the novel ion exchange regeneration method and configuration proposed in the present invention are as follows:

[0128] Ordinary ion exchangers do not have the second acid inlet valve (KV-90E2), the third acid inlet valve (KV-90E3), the second alkali inlet valve (KV-90F2), and the third alkali inlet valve (KV-90F3), and cannot effectively block acid and alkali leakage.

[0129] The common ion exchanger has no lower drain valve (KV-90L), and the drainage is directly discharged into the ditch through the positive wash drain valve (KV-90K) and the middle drain valve (KV-90J)

[0130] Ordinary ion exchangers do not have a conductivity pneumatic valve (KV-90M), and the conductivity of the produced water cannot be measured through the forward wash drainage.

[0131] Before the ordinary ion exchanger enters the acid-base regeneration, the water is drained and part of the water in the container is discharged into the ditch. After the clean water is replaced, the water is filled, as shown in steps 8 and 11.

[0132] In the steps 3 / 6 / 8 / 9 / 10 / 12 / 13 / 15 / 17 of Appendix 2, ordinary ion exchangers directly discharge wastewater into the ditch. The process method proposed in this process (Appendix 1) can collect and treat the wastewater from the steps 3 / 6 / 9 / 10 / 12 / 17 of Appendix 2 (corresponding to the steps 3 / 6 / 8 / 9 / 10 / 15 of Appendix 1), and only the wastewater from the steps 8 / 13 / 15 needs to be discharged into the ditch. Through the innovation of the regeneration process, the typical wastewater recovery rate can reach more than 90% (Example 1).

Claims

1. A water-saving and safe ion exchange regeneration device, characterized in that: Including water inlet pipeline (L001), ion exchanger, alkali inlet pipeline (L201), acid inlet pipeline (L202), compressed air inlet pipeline (L301), and water production pipeline (L002); The water inlet pipeline (L001) is connected to the top of the ion exchanger, and one end of the alkali inlet pipeline (L201) is connected to the top of the ion exchanger through the water inlet pipeline (L001); the other end of the alkali inlet pipeline (L201) is connected to the alkali source; The water production pipeline (L002) is arranged at the bottom of the ion exchanger, and one end of the acid inlet pipeline (L202) and the compressed air inlet pipeline (L301) are both connected to the water production pipeline (L002); the other end of the acid inlet pipeline (L202) is connected to the acid source, and the other end of the compressed air inlet pipeline (L301) is connected to the compressed air source; The water inlet pipeline (L001) is provided with a backwash water inlet pipeline (L101) and a backwash water outlet pipeline (L102), the backwash water inlet pipeline (L101) is connected to the water production pipeline (L002), and the backwash water outlet pipeline (L102) is connected to the wastewater recovery pipeline (L003); The wastewater recovery pipeline (L003) is connected to other wastewater recovery pipelines (L901) of the same type of ion exchangers, a conductivity analyzer (19) is provided on the wastewater recovery pipeline (L003) through a discharge pipeline, and a wastewater discharge valve (20) is provided on the discharge pipeline; The invention also includes that an upper row pipeline (L501) is provided on the top of the ion exchanger, and an upper row valve (6) is provided on the upper row pipeline (L501); The water production pipeline (L002) is provided with a down-discharge pipeline (L502), a drain pipeline (L601), a first resin catcher (15), a positive wash drainage pipeline (L401), and a water production valve (13) in sequence; The lower discharge pipeline (L502) is arranged between the acid inlet pipeline (L202) and the compressed air inlet pipeline (L301), and a lower discharge valve (14) is arranged on the lower discharge pipeline (L502); the drain pipeline (L601) is arranged between the compressed air inlet pipeline (L301) and the first backwash water inlet pipeline (L101), and a drain valve is arranged on the drain pipeline (L601); One end of the forward wash drainage pipeline (L401) is arranged on the water production pipeline (L002), and the other end of the forward wash drainage pipeline (L401) is arranged on the backwash outlet pipeline (L102); A forward wash drainage valve is provided on the forward wash drainage pipeline (L401); The water inlet pipe (L001) is provided with a water inlet valve (4), and the water inlet valve (4) is arranged between the backwash water inlet pipe (L101) and the backwash water outlet pipe (L102); A backwash water inlet valve (7) is provided on the backwash water inlet pipe (L101), and a backwash water outlet valve (5) is provided on the backwash water outlet pipe (L102); A middle row of pipes (L203) is provided in the middle of the ion exchanger, and a middle row of valves (18) and a second resin trap (16) are sequentially provided on the middle row of pipes (L203), and the second resin trap (16) is arranged on a side away from the ion exchanger.

2. A water-saving and safe ion exchange regeneration device according to claim 1, characterized in that: The acid inlet pipeline (L202) is provided with a first acid inlet valve (9), the acid inlet pipeline (L202) is connected in parallel with a first pipeline and a second pipeline, the other end of the first pipeline is connected to the water production pipeline (L002), the first pipeline is provided with a second acid inlet valve (10), and the second pipeline is provided with a third acid inlet valve (11).

3. The water-saving and safe ion exchange regeneration device according to claim 1 is characterized in that: The alkali inlet pipeline (L201) is provided with a first alkali inlet valve (1), and the alkali inlet pipeline (L201) is connected to a third pipeline and a fourth pipeline, and the other end of the fourth pipeline is connected to the water inlet pipeline (L001). The fourth pipeline is provided with a second alkali inlet valve (2), and the third pipeline is provided with a third alkali inlet valve (3).

4. A water-saving and safe ion exchange regeneration method, using a water-saving and safe ion exchange regeneration device according to any one of claims 1 to 3, characterized in that: The steps include: S1: Incoming water enters the ion exchanger through the water inlet pipe (L001), and the water produced by the ion exchanger enters the downstream storage tank through the first resin trap (15) on the water production pipe (L002); S2: Forward wash, the incoming water passes through the water inlet pipe (L001) and the forward wash drainage pipe (L401) into the recovery wastewater pipe (L003), and the conductivity analyzer (19) on the recovery wastewater pipe (L003) measures the conductivity of the produced water; S3: Backwash stratification, the incoming water enters the ion exchanger through the water inlet pipe (L001) and the first backwash water inlet pipe (L101), The backwash water of the ion exchanger is recycled through the water inlet pipe (L001), the backwash outlet pipe (L102), and the wastewater recycling pipe (L003) in sequence; S4: Alkali enters the ion exchanger from the top through the alkali inlet pipe (L201) and the water inlet pipe (L001), and at the same time, acid enters the ion exchanger from the bottom through the acid inlet pipe (L202). The acid reacts with the cation resin, and H+ replaces other cations adsorbed by the cation resin. The alkali reacts with the anion resin, and OH- replaces other anions adsorbed by the anion resin. The acid and alkali after the reaction are recovered as neutralization wastewater through the middle discharge pipe (L203) and the recovery wastewater pipe (L003); S5: Replacement, the excess acid and alkali need to be replaced with water; S6: Compressed air mixed with fat is introduced, and the compressed air enters the ion exchanger from the bottom through the compressed air inlet pipe (L301) and is discharged through the upper pipe (L501); S7: Drain water by gravity flow. The upper valve (6) on the upper pipe (L501) is opened, and the water is discharged into the ditch by gravity flow through the lower pipe (L502).

5. A water-saving and safe ion exchange regeneration method according to claim 4, characterized in that: In the step S4, the first alkali inlet valve (1), the second alkali inlet valve (2), and the third alkali inlet valve (3) are in an open state, and the first acid inlet valve (9), the second acid inlet valve (10), and the third acid inlet valve (11) are in an open state; In the steps S1, S2 and S3, the first alkali inlet valve (1) and the second alkali inlet valve (2) are in a closed state, and the third alkali inlet valve (3) is in an open state; in the steps S1, S2 and S3, the first acid inlet valve (9) and the second acid inlet valve (10) are in a closed state, and the third acid inlet valve (11) is in an open state.

6. A wastewater recovery process for a water-saving and safe ion exchange regeneration device, characterized in that: The steps include: S1: Fresh water used to prepare demineralized water first enters the pre-treatment filter device; S2: Fresh water after filtration passes through a strong acid cation bed to remove cations in the water, and the acidic water enters a denitrification tower to remove the generated carbon dioxide; S3: After decarbonization, the anions in the water are removed by a strong alkaline anion bed, and the produced water enters the mixed bed for secondary refining. The prepared deionized water can be used externally; S4: The regeneration system includes an acid system and an alkali system. The time of adding acid and alkali in the step is adjusted to control the wastewater generated by the synchronous regeneration of the yin and yang beds and the recycled wastewater generated by the mixed bed regeneration to be neutral. The pH value of the wastewater is monitored after mixing, and acid and alkali are added to ensure that the wastewater remains neutral; S5: Recycle wastewater into the pretreatment device to remove excess ammonia nitrogen in the water; S6: The pre-treated wastewater enters the zero-discharge ultrafiltration, weak acid cation bed, and reverse osmosis device for treatment. Part of the regenerated wastewater from the weak acid cation bed can be recycled and mixed with the recycled wastewater from the cation bed, anion bed, and mixed bed, and recycled as high-quality wastewater; S7: The water produced by the reverse osmosis of the zero-discharge device is recycled to the front end of the strong acid cation bed for secondary utilization, and the concentrated water of the reverse osmosis is discharged to the downstream for further treatment, and industrial salt is prepared by the subsequent evaporation and crystallization device; The strong acid cation bed, strong base anion bed, mixed bed and weak acid cation bed use the water-saving and safe ion exchange regeneration method described in claim 4 or 5.

Images