Coal-fired power plant high-low brine advanced treatment recycling system and method based on ion replacement concentration technology

Abstract

The invention provides a coal-fired power plant high-low salt water advanced treatment and recycling method based on an ion replacement concentration technology. Refined treatment iron and manganese removal filter backwashing water, mixed bed regeneration wastewater low-salt water and bed regeneration wastewater high-salt water are fed into an industrial wastewater storage pool to be stored, and quality-divided recycling is achieved; an automatic valve is arranged at an outlet of each industrial wastewater storage pool, and different dosing modes and retention time are adopted; as the industrial wastewater is finally recycled to a desulfurization system, acid and alkali do not need to be added into a final neutralization tank; low-salt water obtained after industrial wastewater treatment enters an iron and manganese removal filter for secondary removal of iron and manganese influencing operation of a desulfurization system, and is finally recycled to the desulfurization system; the mixed bed regeneration wastewater high-salinity water is discharged to a desulfurization wastewater clarification tank and treated together with desulfurization wastewater through ultrafiltration and IRCT systems, and treatment of the high-salinity water and recycling of water resources are achieved; and backwashing process treatment is regularly realized according to different water qualities.

Description

Technical Field

[0001] The present invention relates to the field of industrial wastewater, and belongs to the technology of recycling high and low brine in coal-fired power plants, and in particular to a system and method for deep treatment and recycling of high and low brine in coal-fired power plants based on ion exchange concentration technology. Background Art

[0002] Coal-fired power plants have extensive applications in boiler feed water and condensate polishing. The anionic bed and cation bed of boiler feed water can be replaced by secondary reverse osmosis, and the mixed bed of boiler feed water can be replaced by EDI. Condensate polishing still uses a high-speed mixed bed and cannot be replaced by other technologies. This is mainly due to its high operating temperature, about 55°C for water-cooled units and about 75°C for air-cooled units. The operating pressure is high and reverse osmosis cannot operate under this condition. It also has a large amount of water (this is why condensate polishing is called a high-speed mixed bed). If reverse osmosis and EDI are used, the investment is large (the large amount of water brings about a large treatment scale), so a high-speed mixed bed is used. It is irreplaceable in the condensate polishing of coal-fired power plants.

[0003] The working principle of the mixed bed is mainly based on the ion exchange principle. When water passes through the mixed bed, the cation exchange resin will adsorb the cations in the water, and the anion exchange resin will adsorb the anions in the water. In this way, the ionic impurities in the water are adsorbed by the resin, thereby achieving water purification. As time goes by, the resin will gradually become saturated and can no longer adsorb the ions in the water. At this time, a regeneration process is required to restore the adsorption capacity of the resin. During regeneration, the acid concentration is generally controlled within the range of 4-5%, and the alkali concentration is controlled within the range of 3-4%. The acid-base wastewater has a high salt content due to the use of a large amount of acid and alkali, which makes it difficult to reuse in coal-fired power plants.

[0004] Mixed beds have many advantages, such as high efficiency in desalination, strong adaptability, easy operation and stability. The core issue of the gradual replacement of mixed beds is the strict environmental protection requirements. Power plants choose to reduce the process route of sewage treatment. Reverse osmosis also has environmental protection issues such as waste membrane treatment and concentrated water treatment. If the comprehensive utilization of its recycled wastewater can be effectively solved, its technology will be revitalized. At the same time, there is no relevant alternative technology for the mixed bed of condensate polishing treatment. Although the amount of recycled wastewater is small, there is no effective way to absorb it in coal-fired power plants. If it can be recycled and utilized according to the zero-emission facilities of thermal method in the plant, it will improve the ecological environment to a certain extent.

[0005] Ion Replacement Concentration Technology (IRCT) achieves efficient and selective removal of ionic pollutants in desulfurized slurry. The cations (calcium ions, magnesium ions, sodium ions, etc.) in the slurry are driven by a DC electric field to migrate into the chloride salt concentrated water system, and the anions (chloride ions, sulfate ions, etc.) are migrated into the sodium salt concentrated water system. They work synergistically with the slurry degreasing system. The gypsum and salt in the desulfurized slurry are discharged from the slurry system by vacuum belt conveyors and IRCT equipment respectively, and the desalinated water is recycled into the slurry system, thereby controlling the concentration of ionic components in the slurry within a relatively low range. The ionic components discharged from the slurry system are concentrated in the chloride salt concentrated water system, and the concentration TDS can reach more than 14%, which can be used as resources through separation treatment, but evaporation and drying technology is still used for treatment today.

[0006] In non-zero emission coal-fired power plants, the three types of water, namely, backwash water from the fine treatment iron and manganese removal filter, high-salt water from the mixed bed regeneration wastewater, and low-salt water, are mixed and treated using conventional industrial wastewater treatment methods. They are then discharged after meeting the standards, which can basically achieve normal treatment. However, there are certain environmental risks and a large amount of low-salt water resources are wasted (each time the mixed bed is regenerated, a large amount of desalted water is required for flushing).

[0007] In zero-emission coal-fired power plants, the three types of water, namely, fine treatment iron and manganese removal backwash water, mixed bed regeneration wastewater, high brine and low brine, are mixed and treated with conventional industrial wastewater, and all are used as desulfurization makeup water. However, the fine treatment iron and manganese removal backwash water and the fine treatment mixed bed regeneration high and low brine contain a large amount of iron and manganese ions, which cause the desulfurization slurry to change color, which affects the desulfurization efficiency in small amounts, and the byproduct gypsum changes color, affecting the sales of gypsum, especially in the current real estate downturn. In serious cases, it can only be sent to the purchaser. If the gypsum cannot be shipped out in time, it will seriously affect the operation of the power plant.

[0008] Moreover, since the high-salt water enters the desulfurization system directly without any treatment, the ion content of the desulfurization slurry increases significantly, resulting in insufficient dissolution of calcium and sulfur dioxide, and poor absorption of sulfur dioxide by the desulfurization system, affecting the desulfurization efficiency. In addition, since the oxidation of iron and manganese ions also requires oxygen, sulfur oxidation is incomplete, affecting the quality of gypsum. Due to the entry of a large number of ions, the desulfurization system needs to increase the discharge of wastewater, and the desulfurization wastewater increases dramatically. Summary of the invention

[0009] To solve the above problems, the present invention discloses a mixed bed regeneration deep treatment reuse system and process for a coal-fired power plant based on ion exchange concentration technology, which solves a series of problems of the desulfurization system caused by reuse to desulfurization.

[0010] A method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology, the specific steps of which include the following:

[0011] Step 1: Separation and recovery: the refined iron and manganese removal backwash water, the mixed bed regeneration low brine and the mixed bed regeneration high brine are stored in the industrial wastewater storage tank A, the industrial wastewater storage tank B and the industrial wastewater storage tank C respectively;

[0012] Step 2: Separation treatment: Separate treatment by low-salinity and high-salinity treatment.

[0013] Step 3: System operation control: Monitor the conductivity of low salt water through the conductivity meter to ensure the separate treatment of high salt water and low salt water; empty the wastewater in the industrial wastewater treatment equipment every time the water quality is switched.

[0014] Furthermore, in the high-salt water treatment step, the mixed bed regenerated high-salt water is treated by a desulfurization ultrafiltration device and an IRCT device, and the concentrated high-salt water is recycled by a drying system evaporator.

[0015] Furthermore, the low-salt water enters the pH adjustment tank through the lifting pump 1, and acid or alkali is added to the pH adjustment tank to adjust the pH; the adjusted low-salt water enters the reaction tank, and flocculant is added to the reaction tank for flocculation reaction; the low-salt water after flocculation enters the flocculation tank, and a coagulant aid is added to the flocculation tank for further flocculation; the low-salt water after flocculation enters the clarifier, and sedimentation and separation are carried out in the clarifier, the clean water enters the clean water tank, and the sediment is discharged through the mud outlet; the low-salt water in the clean water tank enters the iron and manganese removal filter through the lifting pump 2.

[0016] Furthermore, the low-salt water treated by the iron and manganese removal filter is recycled to the desulfurization system as make-up water for the desulfurization system.

[0017] Furthermore, the high-salt water enters the pH adjustment tank from the industrial wastewater storage tank C through the lifting pump 1, and acid or alkali is added to the pH adjustment tank for pH adjustment; the adjusted low-salt water enters the reaction tank, and flocculant is added to the reaction tank for flocculation reaction; the low-salt water after flocculation enters the flocculation tank, and a coagulant is added to the flocculation tank for further flocculation; the low-salt water after flocculation enters the clarifier, and sedimentation separation is carried out in the clarifier, the clean water enters the clean water tank, and the sediment is discharged through the mud outlet; the high-salt water in the clean water tank enters the desulfurization wastewater clarification tank and the desulfurization clarification water tank through the lifting pump 2 for mixing; the mixed wastewater is sent to the desulfurization self-cleaning filter through the lifting pump 3 for preliminary filtration, and the filtered wastewater enters the desulfurization ultrafiltration device, and is further filtered through the ultrafiltration membrane to remove suspended matter and large molecular organic matter; the wastewater after ultrafiltration enters the desulfurization ultrafiltration water tank and is sent to the security filter through the lifting pump 4; and enters the IRCT device through the security filter.

[0018] Furthermore, in the IRCT device, the high-salt water is treated by ion exchange concentration technology. The concentrated high-salt water enters the concentrate storage tank and enters the drying system evaporator through the concentrate spray lift pump for evaporation and drying treatment to achieve resource utilization of the high-salt water. The treated clean water is reused in the desulfurization system as make-up water for the desulfurization system.

[0019] Furthermore, the system control operation includes conductivity meter monitoring and emptying operation; wherein the conductivity meter monitoring includes: setting a conductivity meter after the clean water tank lifting pump to monitor the conductivity of low salt water; when the conductivity is higher than the set value of 7-15ms / cm, it is judged as high salt water and enters the desulfurization wastewater treatment system for treatment; when the conductivity is lower than the set value, it is judged as low salt water and enters the iron and manganese removal filter and then reused in the desulfurization system; emptying operation: each time the water quality is switched, the industrial wastewater treatment equipment including the PH adjustment tank, reaction tank, flocculation tank, clarifier, clean water tank, and final neutralization tank needs to be emptied; the emptying method is: first discharge the bottom sediment to the pit sludge tank, and the upper clean water back to the original industrial wastewater storage tank.

[0020] A high and low salt water deep treatment and reuse system for a coal-fired power plant based on ion exchange concentration technology, comprising an industrial wastewater storage tank A, an industrial wastewater storage tank B, and an industrial wastewater storage tank C; wherein the outlets of the industrial wastewater storage tank A, the industrial wastewater storage tank B, and the industrial wastewater storage tank C are connected to a main outlet pipe through automatic valves, and the main outlet pipe is connected to a pH adjustment tank, a reaction tank, a flocculation tank, a clarifier, a clean water tank, and a final neutralization tank in sequence through a lifting pump. The pool is used to store treated low-salt water and high-salt water. The low-salt water in the clean water pool is connected to the iron and manganese removal filter through lifting pump 2; the high-salt water in the clean water pool enters the desulfurization wastewater clarification pool and the desulfurization clarification water tank through lifting pump 2; the mixed wastewater is sent into the desulfurization self-cleaning filter through lifting pump 3, the desulfurization self-cleaning filter is connected to the desulfurization ultrafiltration device, and the desulfurization ultrafiltration device is connected to the desulfurization ultrafiltration water tank; the desulfurization ultrafiltration water tank is connected to the security filter through lifting pump 4; and it enters the IRCT device through the security filter for concentration treatment.

[0021] Furthermore, industrial wastewater storage tank A, industrial wastewater storage tank B, and industrial wastewater storage tank C are used to store respectively the refined iron and manganese removal backwash water, the mixed bed regeneration low brine, and the mixed bed regeneration high brine.

[0022] Furthermore, the high-salt water concentrated in the IRCT device enters the concentrated liquid storage tank, and the concentrated liquid storage tank is recycled through the concentrated liquid spray lift pump and the drying system evaporator.

[0023] The present invention has developed a process route for deep treatment and reuse of high and low brine in mixed bed regeneration of coal-fired power plants based on ion exchange concentration technology. The backwash water of the finely treated iron and manganese removal filter is sent to the industrial wastewater storage tank, the low-salt water of the mixed bed regeneration wastewater is sent to the industrial wastewater storage tank, and the high-salt water of the mixed bed regeneration wastewater is sent to the industrial wastewater storage tank for storage to achieve quality-based recovery; according to the characteristics of the three types of water quality, automatic valves are set at the outlets of the industrial wastewater storage tank, the industrial wastewater storage tank, and the industrial wastewater storage tank, and automatic valves are set at the outlets of each industrial wastewater storage tank, and different The dosing method and residence time are determined; the residence time is changed by adjusting the manual valve of the lifting pump 1 or by frequency conversion of the lifting pump 1 to change the treated water flow; the treatment of industrial wastewater is completed, and since it is finally reused in the desulfurization system, there is no need to add acid and alkali in the final neutralization tank; the water after the iron and manganese removal backwash water and the low-salt water treatment of the mixed bed regeneration wastewater are collectively referred to as low-salt water, which enters the iron and manganese removal filter for secondary removal of iron and manganese that affect the operation of the desulfurization system, and is finally reused in the desulfurization system; the high-salt water of the mixed bed regeneration wastewater is discharged to the desulfurization wastewater clarification tank, and together with the desulfurization wastewater, it is treated by ultrafiltration and IRCT system to achieve the treatment of high-salt water and the reuse of water resources;

[0024] (1) According to the characteristics of the three types of water quality, an automatic valve is set at the outlet of the industrial wastewater storage tank, and different dosing methods and retention times are used (the retention time adopts the method of adjusting the manual valve of lift pump 1 or the frequency conversion method of lift pump 1 to change the treated water flow rate.) to complete the treatment of industrial wastewater. Since it is finally reused in the desulfurization system, there is no need to add acid and alkali in the final neutralization tank. Since the backwashing cycle of the fine treatment iron and manganese removal filter and the mixed bed regeneration are both long (generally more than 45 days), each time the backwashing of the treated water quality filter and the mixed bed regeneration water are switched, the industrial wastewater treatment equipment (PH adjustment tank\reaction tank\flocculation tank\clarifier\clean water tank\final neutralization tank) needs to be emptied. In order to save overall investment, the final neutralization tank can be equipped with no submersible lift pump. During its regular treatment, a temporary submersible lift pump is used for cleaning. The small amount of wastewater has little impact on the operation. The recommended volume ratio of the clean water tank and the final neutralization tank is about 4:1).

[0025] (2) Discharge method: The pH adjustment tank, reaction tank, flocculation tank and clarifier are all equipped with bottom discharge valves to first discharge the bottom sediment into the underground sludge pool (the sludge pool will be transported to the sludge treatment room for centralized dehydration), and then the upper clean water is discharged back to the original industrial wastewater storage tank.

[0026] (3) The final neutralization tank and the clean water tank adopt a rotary overflow design. The recommended volume ratio of the clean water tank and the final neutralization tank is about 4:1 to improve the water quality. The final neutralization tank is regularly cleaned with a submersible lift pump.

[0027] (4) Fine treatment of iron and manganese removal backwash water and mixed bed regeneration wastewater. The water after low-salt water treatment is collectively referred to as low-salt water. It enters the iron and manganese removal filter for secondary removal of iron and manganese that affect the operation of the desulfurization system, and is finally reused in the desulfurization system.

[0028] (5) The high-salt water in the mixed bed regeneration wastewater is discharged to the desulfurization wastewater clarification tank and treated together with the desulfurization wastewater by ultrafiltration and IRCT system to achieve the treatment of high-salt water and reuse of water resources.

[0029] (6) A conductivity meter is installed after the lifting pump of the clean water tank. The conductivity meter is used to determine the salt content in the water. When it is higher than the set value, it is judged as high salt water and is treated by a zero discharge system. Otherwise, it is filtered by an iron and manganese removal filter and reused. The conductivity value is generally set between 7ms / cm-15ms / cm and can be adjusted according to the conductivity of the desulfurization slurry. When the desulfurization slurry is high, it should be set lower, and when the desulfurization slurry is low, it should be set higher.

[0030] Beneficial effects of the present invention:

[0031] 1. Fine treatment of iron and manganese removal backwash water, high-salt water of mixed bed regeneration wastewater, and quality recovery of low-salt water of mixed bed regeneration wastewater;

[0032] 2. Set different dosages according to different water qualities to achieve better treatment effects;

[0033] 3. Before the low-salt water is reused in the desulfurization system, an iron and manganese removal filter is installed to reduce the entry of iron and manganese into the desulfurization system and improve the desulfurization operation effect;

[0034] 4. Coupled with the zero emission system of coal-fired power plants, the high-salt water in the mixed bed regeneration wastewater is treated and reused to avoid the adverse effects of high-salt water on the desulfurization system.

[0035] 5. It is particularly suitable for coal-fired power plants that have adopted ion replacement concentration technology (IRCT for short). BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 , a flow chart of the process system of the present invention. DETAILED DESCRIPTION

[0037] The present invention is further explained below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0038] As shown in the figure, the list is as follows

[0039] Serial number name Serial number name 1 Fine treatment of iron and manganese removal backwash water 26 #3 Loop Box 2 Mixed bed regeneration low brine 26.1 #3 Circulation Pump 3 Mixed bed regeneration high brine 26.2 #3 Security Filter 4 Industrial wastewater storage tank A 26.3 #3 Heat Exchanger 5 Industrial wastewater storage tank B 27 #4 Loop Box 6 Industrial wastewater storage tank C 27.1 #4 Circulation Pump 7 atmosphere 27.2 #4 Security Filter 8 Roots blower 27.3 #4 Heat Exchanger 9 PH adjustment tank 28 #2 Loop Box 9.1 Acidification 28.1 #2 Circulation Pump 9.2 Add alkali 28.2 #2 Security Filter 10 Reaction tank 28.3 #2 Heat Exchanger 10.1 Add flocculant 29 #5 Loop Box 11 Flocculation tank 29.1 Aeration fan 11.1 Add coagulant 29.2 #5 Circulation Pump 12 Clarifier 29.3 #5 Security Filter 13 Final neutralization tank 29.4 #5 Heat Exchanger 14 Clean water pool 30 #6 Loop Box 15 Low salt water 30.1 Aeration fan 16 High salt water 30.2 #6 Circulation Pump 17 Iron and manganese removal filter 30.3 #6 Security Filter 16 High salt water 30.4 #6 Heat Exchanger 17 Iron and manganese removal filter 31 Reducing agent dosing device 18 Reuse to make up water for desulfurization system 31.1 Reductant dosing pump 19 Desulfurization wastewater clarification tank 32 Acid dosing device 20 Desulfurization clarified water tank 32.1 Acid dosing pump 21 Desulfurization self-cleaning filter 33 Desalination liquid drainage tank 22 Desulfurization ultrafiltration device 34 Concentrate storage tank 22.1 Desulfurization ultrafiltration backwash water pump 35 Concentrate buffer tank 23 Desulfurization ultrafiltration water tank 35.1 Concentrated liquid spray lift pump 24 Security Filters 36 Drying system evaporator 25 #1 Loop Box 37 High temperature smoke 25.1 #1 Circulation Pump 38 Air preheater outlet flue 25.2 #1 Security Filter 39 IRCT device 25.3 #1 Heat Exchanger Note 1 Mud discharge Note 2 Flue gas, smoke, evaporated solids and water vapor mixture

[0040] A method for deep treatment and reuse of high and low brine in coal-fired power plants based on ion exchange concentration technology.

[0041] Step 1: Separation and recovery: the refined iron and manganese removal backwash water 1, the mixed bed regeneration low brine 2 and the mixed bed regeneration high brine 3 are stored in the industrial wastewater storage tank A4, the industrial wastewater storage tank B5 and the industrial wastewater storage tank C6 respectively;

[0042] Step 2: Separation treatment: Separate treatment by low-salinity and high-salinity treatment.

[0043] Step 3: System operation control: Monitor the conductivity of low salt water through the conductivity meter to ensure the separate treatment of high salt water and low salt water; empty the wastewater in the industrial wastewater treatment equipment every time the water quality is switched.

[0044] The low-salt water treatment specifically includes the low-salt water entering the pH adjustment tank 9 through the lifting pump 1, and adding acid 9.1 or alkali 9.2 to the pH adjustment tank for pH adjustment; the adjusted low-salt water enters the reaction tank 10, and adding flocculant 10.1 to the reaction tank for flocculation reaction; the low-salt water after flocculation enters the flocculation tank 11, and adding coagulant aid 11.1 to the flocculation tank for further flocculation; the low-salt water after flocculation enters the clarifier 12, and is precipitated and separated in the clarifier, and the clean water enters the clean water tank 14, and the sediment is discharged through the mud outlet; the low-salt water 15 in the clean water tank 14 enters the iron and manganese removal filter 17 through the lifting pump 2; the low-salt water 15 treated by the iron and manganese removal filter 17 is recycled to the desulfurization system 18 as water replenishment for the desulfurization system.

[0045] The treatment of high-salt water specifically includes high-salt water entering the pH adjustment tank 9 from the industrial wastewater storage tank C6 through the lifting pump 1, adding acid 9.1 or alkali 9.2 to the pH adjustment tank for pH adjustment; the adjusted low-salt water enters the reaction tank 10, adding flocculant 10.1 to the reaction tank for flocculation reaction; the flocculated low-salt water enters the flocculation tank 11, adding coagulant aid 11.1 to the flocculation tank for further flocculation; the flocculated low-salt water enters the clarifier 12, and sedimentation and separation are carried out in the clarifier, and the clean water enters the clean water tank 14, The sediment is discharged through the mud outlet; the high-salt water 16 in the clean water tank 14 enters the desulfurization wastewater clarification tank 19 and the desulfurization clarification water tank 20 through the lifting pump 2 for mixing; the mixed wastewater is sent to the desulfurization self-cleaning filter 21 through the lifting pump 3 for preliminary filtration; the filtered wastewater enters the desulfurization ultrafiltration device 22, and is further filtered through the ultrafiltration membrane to remove suspended matter and macromolecular organic matter; the ultrafiltered wastewater enters the desulfurization ultrafiltration water tank 23 and is sent to the security filter 24 through the lifting pump 4; it enters the IRCT device 39 through the security filter 24; the concentrated high-salt water is recycled through the drying system evaporator 36; it is evaporated and dried through the drying system evaporator 36 to realize the resource utilization of high-salt water; the treated clean water is reused in the desulfurization system 18 as make-up water for the desulfurization system.

[0046] The system control operation includes conductivity meter monitoring and emptying operation; the conductivity meter monitoring includes: setting a conductivity meter after the clean water tank lifting pump to monitor the conductivity of low salt water; when the conductivity is higher than the set value of 7-15ms / cm, it is judged as high salt water and enters the desulfurization wastewater treatment system for treatment; when the conductivity is lower than the set value, it is judged as low salt water and enters the iron and manganese removal filter and is reused in the desulfurization system; emptying operation: each time the water quality is switched, the industrial wastewater treatment equipment including the PH adjustment tank 9, the reaction tank 10, the flocculation tank 11, the clarifier 12, the clean water tank 14, and the final neutralization tank 13 need to be emptied; the emptying method is: first discharge the bottom sediment to the pit sludge tank, and discharge the upper clean water back to the original industrial wastewater storage tank.

[0047] Among them, industrial wastewater storage tank A4, industrial wastewater storage tank B5 and industrial wastewater storage tank C6 are used to store the finely treated iron and manganese removal backwash water 1, the mixed bed regeneration low brine 2 and the mixed bed regeneration high brine 3 respectively.

[0048] The high-salt water passes through the desulfurization wastewater clarification tank and then passes through the desulfurization clarification water tank, the desulfurization self-cleaning filter, the desulfurization ultrafiltration device, the desulfurization ultrafiltration water tank, and the security filter and is sent to the IRCT device 39; the specific flow of the concentration of the IRCT device 39 can be found in CN117695851A, which will not be described in detail.

[0049] Anti-corrosion design: The tank bodies and equipment of industrial wastewater storage tank A4, industrial wastewater storage tank B5, and industrial wastewater storage tank C(6) must be designed with corresponding anti-corrosion according to the water quality characteristics to ensure the long-term stable operation of the system.

[0050] Rotation overflow design: The final neutralization tank 13 and the clean water tank 14 adopt a rotation overflow design to ensure the quality of the produced water. The volume ratio of the clean water tank and the final neutralization tank is recommended to be 4:1 to improve the treatment efficiency.

[0051] Roots blower 8: used to provide aeration to ensure that the wastewater in the reaction tank 10 and the flocculation tank 11 are fully mixed.

[0052] #1 circulation box 25, #1 circulation pump 25.1, #1 safety filter 25.2, #1 heat exchanger 25.3: used for circulating wastewater in the treatment system to ensure efficient operation of the system.

[0053] #2 circulation box 28, #2 circulation pump 28.1, #2 safety filter 28.2, #2 heat exchanger 28.3: used for circulating wastewater in the treatment system to ensure efficient operation of the system.

[0054] #3 circulation box 26, #3 circulation pump 26.1, #3 safety filter 26.2, #3 heat exchanger 26.3: used for circulating wastewater in the treatment system to ensure efficient operation of the system.

[0055] #4 circulation box 27, #4 circulation pump 27.1, #4 safety filter 27.2, #4 heat exchanger 27.3: used for circulating wastewater in the treatment system to ensure efficient operation of the system.

[0056] #5 circulation box 29, #5 circulation pump 29.2, #5 safety filter 29.3, #5 heat exchanger 29.4: used to circulate wastewater in the treatment system to ensure efficient operation of the system.

[0057] #6 circulation box 30, #6 circulation pump 30.2, #6 safety filter 30.3, #6 heat exchanger 30.4: used for circulating wastewater in the treatment system to ensure efficient operation of the system.

[0058] Reductant dosing device 31, reductant dosing pump 31.1: used to add reductant to the system to ensure smooth chemical reaction in the wastewater treatment process.

[0059] Acid dosing device 32, acid dosing pump 32.1: used to add acid to the system to ensure pH adjustment during wastewater treatment.

[0060] Desalted liquid drainage tank 33: used to store desalted liquid to ensure the normal operation of the system.

[0061] The concentrated liquid storage tank 34 and the concentrated liquid buffer tank 35 are used to store concentrated high-salt water to ensure resource utilization of high-salt water.

[0062] High-temperature flue gas 37 and air preheater outlet flue 38 are used to provide high-temperature flue gas to ensure efficient operation of the drying system evaporator 36.

Claims

1. A method for deep treatment and reuse of high and low brine in coal-fired power plants based on ion exchange concentration technology, characterized in that: Step 1: Separation and recovery: the refined iron and manganese removal backwash water (1), the mixed bed regeneration low brine (2) and the mixed bed regeneration high brine (3) are stored in the industrial wastewater storage tank A (4), the industrial wastewater storage tank B (5) and the industrial wastewater storage tank C (6) respectively; Step 2: Separation treatment: Separate treatment by low-salinity and high-salinity treatment. Step 3: System operation control: Monitor the conductivity of low salt water through the conductivity meter to ensure the separate treatment of high salt water and low salt water; empty the wastewater in the industrial wastewater treatment equipment every time the water quality is switched.

2. The method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology according to claim 1, characterized in that: The low-salt water treatment specifically includes the low-salt water entering the pH adjustment tank (9) through the lifting pump 1, adding acid (9.1) or alkali (9.2) to the pH adjustment tank for pH adjustment; the adjusted low-salt water enters the reaction tank (10), adding flocculant (10.1) to the reaction tank for flocculation reaction; the low-salt water after flocculation enters the flocculation tank (11), adding coagulant aid (11.1) to the flocculation tank for further flocculation; the low-salt water after flocculation enters the clarifier (12), and sedimentation and separation are carried out in the clarifier, and the clean water enters the clean water tank (14), and the sediment is discharged through the mud outlet; the low-salt water (15) in the clean water tank (14) enters the iron and manganese removal filter (17) through the lifting pump 2.

3. The method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology according to claim 2, characterized in that: The low salt water (15) treated by the iron and manganese removal filter (17) is recycled to the desulfurization system (18) as make-up water for the desulfurization system.

4. The method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology according to claim 1, characterized in that: The treatment of high-salt water specifically includes high-salt water entering a pH adjustment tank (9) from an industrial wastewater storage tank C (6) through a lifting pump, and adding an acid (9.1) or an alkali (9.2) to the pH adjustment tank for pH adjustment; the adjusted low-salt water enters a reaction tank (10), and a flocculant (10.1) is added to the reaction tank for flocculation reaction; the low-salt water after flocculation enters a flocculation tank (11), and a coagulant (11.1) is added to the flocculation tank for further flocculation; the low-salt water after flocculation enters a clarifier (12), and sedimentation separation is carried out in the clarifier, and the clean water enters a clean water tank (14), and the sediment is passed through The wastewater is discharged through the mud outlet; the high-salt water (16) in the clean water tank (14) enters the desulfurization wastewater clarification tank (19) and the desulfurization clarification water tank (20) through the lifting pump 2 for mixing; the mixed wastewater is sent to the desulfurization self-cleaning filter (21) through the lifting pump 3 for preliminary filtration. The filtered wastewater enters the desulfurization ultrafiltration device (22) and is further filtered through the ultrafiltration membrane to remove suspended matter and large molecular organic matter; the wastewater after ultrafiltration enters the desulfurization ultrafiltration water tank (23) and is sent to the security filter (24) through the lifting pump 4; and enters the IRCT device (39) through the security filter (24).

5. The method for deep treatment and reuse of high and low brine in coal-fired power plants based on ion exchange concentration technology according to claim 4, characterized in that: In the high-salt water treatment step, the mixed bed regenerated high-salt water is treated by a desulfurization ultrafiltration device (22) and an IRCT device (39), and the concentrated high-salt water is recycled by a drying system evaporator (36).

6. The method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology according to claim 5, characterized in that: The drying system evaporator (36) performs evaporation and drying treatment to realize resource utilization of high-salt water; the treated clean water is recycled to the desulfurization system (18) as water replenishment for the desulfurization system.

7. The method for deep treatment and reuse of high and low brine in a coal-fired power plant based on ion exchange concentration technology according to claim 1, characterized in that: The system control operation includes conductivity meter monitoring and emptying operation; wherein the conductivity meter monitoring includes: setting a conductivity meter after the clean water tank lifting pump to monitor the conductivity of the low salt water; when the conductivity is higher than the set value of 7-15 ms / cm, it is judged as high salt water and enters the desulfurization wastewater treatment system for treatment; when the conductivity is lower than the set value, it is judged as low salt water and enters the iron and manganese removal filter and is reused in the desulfurization system; emptying operation: each time the water quality is switched, it is necessary to empty the wastewater in the industrial wastewater treatment equipment including the pH adjustment tank (9), the reaction tank (10), the flocculation tank (11), the clarifier (12), the clean water tank (14), and the final neutralization tank (13); the emptying method is: first discharge the bottom sediment to the pit sludge tank, and discharge the upper clean water back to the original industrial wastewater storage tank.

8. A high and low brine deep treatment and reuse system for coal-fired power plants based on ion exchange concentration technology, characterized by: The invention comprises an industrial wastewater storage tank A (4), an industrial wastewater storage tank B (5), and an industrial wastewater storage tank C (6); wherein the outlets of the industrial wastewater storage tank A (4), the industrial wastewater storage tank B (5), and the industrial wastewater storage tank C (6) are connected to a main outlet pipe through automatic valves, and the main outlet pipe is connected to a pH adjustment tank (9), a reaction tank (10), a flocculation tank (11), a clarifier (12), a clean water tank (14), and a final neutralization tank (13) in sequence through a lifting pump, wherein the clean water tank (14) and the final neutralization tank (13) are used to store treated low-salt water and high-salt water, and the low-salt water in the clean water tank (14) is connected to the reaction tank (10), the flocculation tank (11), the clarifier (12), the clean water tank (14), and the final neutralization tank (13). The salt water (15) is connected to the iron and manganese removal filter (17) through the lifting pump 2; the high salt water (16) in the clean water tank (14) enters the desulfurization wastewater clarification tank (19) and the desulfurization clarification water tank (20) through the lifting pump 2; the mixed wastewater is sent to the desulfurization self-cleaning filter (21) through the lifting pump 3, the desulfurization self-cleaning filter (21) is connected to the desulfurization ultrafiltration device (22), and the desulfurization ultrafiltration device (22) is connected to the desulfurization ultrafiltration water tank (23); wherein the desulfurization ultrafiltration water tank (23) is connected to the security filter (24) through the lifting pump 4; and enters the IRCT device (39) through the security filter (24) for concentration treatment.

9. The high and low brine deep treatment and reuse system for coal-fired power plants based on ion exchange concentration technology according to claim 8 is characterized by: Industrial wastewater storage tank A (4), industrial wastewater storage tank B (5), and industrial wastewater storage tank C (6) are used to store the refined iron and manganese removal backwash water (1), the mixed bed regeneration low salt water (2), and the mixed bed regeneration high salt water (3), respectively.

10. The high and low brine deep treatment and reuse system for coal-fired power plants based on ion exchange concentration technology according to claim 8, characterized in that: The high-salt water concentrated in the IRCT device (39) enters the concentrated liquid storage tank (34), and the concentrated liquid storage tank (34) is recycled through the concentrated liquid spray lift pump (35.1) and the drying system evaporator (36).

Images