Desulfurization wastewater anion dispersion scale reduction concentration decrement device

Abstract

The utility model discloses a desulfurization wastewater anion dispersion scale reduction concentration decrement device, which belongs to the technical field of desulfurization wastewater treatment and structurally comprises a plurality of anion screening membranes, anti-pollution cation membranes, partition plates, a cathode plate a, an anode plate a, a cathode plate b and an anode plate b. The anion screening membranes and the anti-pollution cation membranes are alternately stacked to form three dispersion units, and the three dispersion units are fixedly connected with the cathode plate a, the anode plate a, the cathode plate b and the anode plate b through a plurality of fasteners. The anion dispersion, scale reduction, concentration and reduction device for desulfurization wastewater has extremely low requirements on pretreatment of desulfurization wastewater, can realize high-power concentration, can prevent feed liquid from depositing on the surface of the separation net, and reduces the scaling tendency of an anti-pollution cation membrane and an anion screening membrane, so that fresh water obtained after dialysis of the desulfurization wastewater almost does not contain chloride ions; and the water can be directly recycled to a desulfurization system, so that the recycling of water resources is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of desulfurization wastewater treatment, in particular to a desulfurization wastewater anion dispersion, descaling, concentration and reduction device. Background Art

[0002] Wet flue gas desulfurization technology is a method widely used in large coal-fired power plants. It uses limestone and gypsum as the main desulfurizer. This technology is mature and reliable, with a wide range of applications. It can effectively reduce the sulfur oxide content in flue gas and is widely used in power plants with different types of coal. In order to maintain the chloride ion concentration in the desulfurization tower below 20,000 mg / L, desulfurization wastewater needs to be discharged. The "zero emission" process of desulfurization wastewater generally follows the basic route of "pretreatment-concentration reduction-terminal solidification crystallization". Among them, the concentration and reduction treatment of desulfurization wastewater can effectively reduce the amount of water in the terminal evaporation and solidification treatment, reduce the comprehensive treatment cost, and realize the cascade utilization of water resources. It is the focus of "zero emission" of wastewater.

[0003] At present, there are two main processes for concentrating high-salt wastewater from thermal power plants, namely thermal concentration and membrane concentration. Thermal concentration mainly includes mechanical vapor recompression, low-temperature multi-effect distillation, multi-stage flash evaporation, low-temperature flue gas concentration and other processes. The first three concentration technologies have strict requirements on softening the desulfurization wastewater; although low-temperature flue gas concentration does not require softening of the wastewater, its high shutdown frequency, easy damage to thermal balance, and unstable evaporation water volume have also become thorny problems; membrane concentration mainly includes reverse osmosis, forward osmosis, electrodialysis technology, etc. Conventional membrane concentration technology requires pre-softening of the wastewater, which has strict requirements; and traditional chemical softening requires a large amount of dosage and has limited room for adjustment to water quality fluctuations.

[0004] The terminal solidification crystallization treatment technologies for desulfurization wastewater include main flue evaporation technology, bypass hot flue gas evaporation technology, low-temperature multi-effect flash concentration technology, etc. No matter which solidification crystallization technology is used, in order to avoid scaling and clogging of the terminal evaporation and solidification system by a large amount of Ca2+, Mg2+, and SO42- plasma in the desulfurization wastewater, the desulfurization wastewater must be softened or the physical and chemical environment of hardness scaling must be destroyed before entering the terminal solidification crystallization system.

[0005] In order to achieve high concentration of desulfurization wastewater, improve the utilization of desulfurization wastewater water resources, avoid scaling and clogging in the desulfurization wastewater concentration and reduction system and the terminal evaporation and solidification system, and realize the recycling of desulfurization wastewater, a desulfurization wastewater anion dispersion scale reduction and concentration reduction device was proposed after long-term active exploration. Utility Model Content

[0006] In order to solve the deficiencies in the above-mentioned prior art, the purpose of the utility model is to provide a desulfurization wastewater anion dispersion scale reduction and concentration reduction device, which has extremely low pretreatment requirements for desulfurization wastewater, can curb the formation of sulfate crystals, and achieve high-fold concentration. During operation, it can ensure that the water quality in each frame chamber is evenly mixed, and can also prevent the deposition of the feed liquid on the surface of the partition screen, thereby reducing the scaling tendency of the anti-pollution cation membrane and the anion screening membrane, ensuring the high-efficiency and stable operation of the device. The fresh water after the desulfurization wastewater is dialyzed contains almost no chloride ions and can be directly reused in the desulfurization system, thereby improving the recycling of water resources.

[0007] The technical solution adopted by the utility model to solve its technical problems is:

[0008] Provided is a desulfurization wastewater anion dispersion scale reduction and concentration reduction device, comprising a plurality of anion screening membranes, anti-pollution cation membranes and partitions, wherein the anion screening membranes and the anti-pollution cation membranes are alternately stacked to form a dispersion unit, and adjacent anion screening membranes and anti-pollution cation membranes are separated from each other by partitions to alternately form a fresh water chamber and a concentrated water chamber, the partition is a plate-frame structure, and a partition net is fixed inside the partition, the number of the dispersion units is three and they are a primary dispersion unit, an enrichment unit and a secondary dispersion unit, a cathode plate a is provided on the top of the primary dispersion unit, an anode plate a is provided between the primary dispersion unit and the enrichment unit, a cathode plate b is provided between the enrichment unit and the secondary dispersion unit, an anode plate b is provided at the bottom of the secondary dispersion unit, and the three dispersion units are fixedly connected to the cathode plate a, the anode plate a, the cathode plate b and the anode plate b by a plurality of fasteners;

[0009] A water inlet channel and a water outlet channel are provided in the plurality of partitions, and a plurality of slit channels are provided on both inner sides of the partitions, and the water inlet channel and the water outlet channel are both connected to the slit channels;

[0010] The plurality of partitions are composed of a top dilute chamber partition, a top concentrated chamber partition, a bottom dilute chamber partition, a bottom concentrated chamber partition and a plurality of middle partitions, the plurality of middle partitions are composed of a plurality of middle dilute chamber partitions and middle concentrated chamber partitions with the same structure, and the plurality of middle dilute chamber partitions and middle concentrated chamber partitions are alternately stacked;

[0011] The internal frame chambers of the top dilute chamber partition, the middle dilute chamber partition and the bottom dilute chamber partition are all fresh water chambers, and several of the fresh water chambers are connected through a group of internal flow channels for circulation. The internal frame chambers of the top concentrated chamber partition, the middle concentrated chamber partition and the bottom concentrated chamber partition are all concentrated water chambers, and several of the concentrated water chambers are connected through another group of internal flow channels for circulation.

[0012] Furthermore, the two groups of internal flow channels include two groups of connecting flow channels a, two groups of connecting flow channels b and several groups of docking flow channels a and docking flow channels b opened on different partitions, and the connecting flow channels a, docking flow channels a, docking flow channels b and connecting flow channels b in each internal flow channel are vertically connected.

[0013] Further, two groups of the connecting flow channels a are respectively opened on the lower surface of the top dilute chamber partition and the top concentrated chamber partition, the top dilute chamber partition is stacked on the top of the top concentrated chamber partition, the water inlet flow channel and the water outlet flow channel are both connected to the connecting flow channel a, and one group of docking flow channels b is opened on the upper surface of the top concentrated chamber partition, and the docking flow channels b are connected to a group of connecting flow channels a on the top dilute chamber partition;

[0014] One side of the top dilute chamber partition is fixedly connected with a liquid inlet a and a liquid outlet a, and the liquid inlet a and the liquid outlet a are respectively connected to the water inlet flow channel and the water outlet flow channel. One side of the top concentrated chamber partition is fixedly connected with a liquid inlet b and a liquid outlet b, and the liquid inlet b and the liquid outlet b are respectively connected to the water inlet flow channel and the water outlet flow channel.

[0015] Furthermore, several groups of the docking channels a and the docking channels b are respectively opened on the middle partition, the water inlet channel and the water outlet channel in the middle partition are connected to the docking channel a, and the docking channel a on the adjacent middle partition is connected to the docking channel b.

[0016] Furthermore, several groups of the docking channels a and the docking channels b are respectively opened on the middle partition, the water inlet channel and the water outlet channel in the middle partition are connected to the docking channel a, and the docking channel a on the adjacent middle partition is connected to the docking channel b.

[0017] Furthermore, the partition is a thermoplastic elastic plate frame, a plurality of reinforcing ribs are arranged inside the partition net, the partition net is a diamond grid structure, and the thickness of the reinforcing ribs is 1-1.05 times the thickness of the partition net.

[0018] Furthermore, the fastener includes a fastening screw and a nut, the threaded end of the fastening screw sequentially passes through the cathode plate a, the primary dispersion unit, the anode plate a, the enrichment unit, the cathode plate b, the secondary dispersion unit and the anode plate b and cooperates with the nut thread, and insulating supports are fixedly installed at the four corners of the lower surface of the anode plate b.

[0019] Furthermore, the plurality of slit channels are divided into two groups, the upper and lower groups, the two groups of slit channels are separated by a partition net, and the two groups of slit channels are staggered, and each group of slit channels is equidistantly arranged along a straight line on the inner side of the partition.

[0020] Furthermore, the anion screening membrane is a modified sulfonated polyetheretherketone ion membrane equipped with grafted ionic organic functional groups, and the lower surface of the cathode plate a and the upper surface of the anode plate b are both provided with polar water chambers, and the upper and lower surfaces of the anode plate a and the cathode plate b are both provided with the same polar water chambers, and the interior of the polar water chambers is configured with brine.

[0021] Compared with the prior art, the beneficial effects of the utility model are:

[0022] 1. The desulfurization wastewater anion dispersion scale reduction and concentration reduction device exemplified in the utility model has extremely low pretreatment requirements for desulfurization wastewater compared to traditional electrodialysis devices. The desulfurization wastewater does not need to be softened and pretreated. It can directly enter the device after simple precipitation and filtration processes. The SO42- and Cl-, Ca2+, and Mg2+ in the desulfurization wastewater are separated through multi-stage dispersion screening of a primary dispersion unit, an enrichment unit, and a secondary dispersion unit. During the concentration process, the concentration of SO42- in the electrodialysis concentrated water hardly changes, while the concentration of cations such as Ca2+ and Mg2+ is significantly increased, making it difficult to form a physical and chemical environment that satisfies sulfate crystallization, curbing the formation of sulfate crystallization, effectively preventing the precipitation of a large amount of sulfate crystals, avoiding the thickening of electrodialysis concentrated water, and achieving high-multiple concentrated water of desulfurization wastewater, reducing the processing pressure of the terminal evaporation crystallization system of desulfurization wastewater, and adapting to the processing scale of the terminal evaporation crystallization system. Therefore, it will not cause the risk of scaling and clogging to the evaporation crystallization system, and is easy to assemble and debug.

[0023] 2. The desulfurization wastewater anion dispersion, descaling, concentration and reduction device exemplified in the utility model has an anti-pollution cation membrane that only allows cations to pass through, and an anion screening membrane that only allows monovalent anions to pass through, while blocking polyvalent ions, so that monovalent anions gather in the concentrated water flow. The internal circulation flow channel formed among the inlet flow channel, the outlet flow channel, the gap flow channel and the internal flow channel enables the desulfurization wastewater to be evenly distributed in the concentrated water chamber and the fresh water chamber, ensuring that the water quality in each frame chamber is evenly mixed. The desulfurization wastewater flows out from the inlet flow channel through the gap flow channel, and the water flow flushes the anti-pollution cation membrane and the anion screening membrane before entering the outlet flow channel through the gap flow channel, which promotes the mixing of the water flow while reducing the scaling tendency of the anti-pollution cation membrane and the anion screening membrane, ensuring the stable dispersion and concentration of the desulfurization wastewater by the device.

[0024] 3. The desulfurization wastewater anion dispersion scale reduction and concentration reduction device exemplified in the utility model has two sets of upper and lower slit flow channels staggered in distribution. During the discharge or entry of the desulfurization wastewater through the two sets of slit flow channels, the desulfurization wastewater will form multiple streams in the frame chamber. The collision of the multiple streams will form turbulence. The reinforcing ribs divide the partition into multiple upper and lower convection channels, further increasing the turbulence of the liquid, so that the anti-pollution cation membrane, the anion screening membrane and the partition can be washed by the larger turbulence, preventing the liquid from depositing on the surface of the partition, and further reducing the scaling tendency of the anti-pollution cation membrane and the anion screening membrane, thereby ensuring the efficient and stable operation of the device.

[0025] 4. The anion dispersion, scale reduction, concentration and reduction device for desulfurization wastewater in the utility model is an anion screening membrane that adopts a modified sulfonated polyetheretherketone ion membrane equipped with grafted ionic organic functional groups, which has an excellent screening effect on monovalent anions. Under the action of a DC electric field, the ions in the desulfurization wastewater migrate in a direction, and the monovalent anions in the fresh water chamber pass through the anion screening membrane and gather in the concentrated water chamber, while the polyvalent ions remain in the fresh water, thereby achieving the effect of dispersing and screening the monovalent anions and polyvalent anions, so that the fresh water after the desulfurization wastewater is dialyzed contains almost no chloride ions and can be directly reused in the desulfurization system without the need for secondary treatment, which is energy-saving and environmentally friendly, and improves the recycling of water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0027] Figure 1 It is a structural schematic diagram of the utility model;

[0028] Figure 2 It is a structural schematic diagram of the utility model from another angle;

[0029] Figure 3 It is a front view of the cathode plate a, the anode plate a and the primary dispersion unit of the utility model when assembled;

[0030] Figure 4 It is a structural schematic diagram of the utility model when the top desalination chamber partition and the partition net are connected;

[0031] Figure 5 It is a schematic diagram of the structure of the top desalination chamber partition of the utility model after transverse section;

[0032] Figure 6 It is a structural schematic diagram of the top desalination chamber partition of the utility model after longitudinal section;

[0033] Figure 7 It is a structural schematic diagram of the middle partition of the utility model after longitudinal sectioning;

[0034] Figure 8 It is a structural schematic diagram of the bottom desalination chamber partition of the utility model after longitudinal section;

[0035] Fig. 9 It is a schematic diagram of the water flow direction inside the dispersion unit of the utility model;

[0036] Fig.10 This is a process flow chart of the utility model for the anion dispersion, descaling, concentration and reduction of desulfurization wastewater.

[0037] In the figure, 1. cathode plate a, 2. anode plate a, 3. cathode plate b, 4. anode plate b, 5. fastening screw, 6. insulating support, 7. top dilute chamber partition, 8. liquid inlet a, 9. liquid outlet a, 10. top concentrated chamber partition, 11. liquid inlet b, 12. liquid outlet b, 13. polar water chamber, 14. anion screening membrane, 15. anti-pollution cation membrane, 16. middle dilute chamber partition, 17. middle concentrated chamber partition, 18. bottom dilute chamber partition, 19. bottom concentrated chamber partition, 20. partition, 21. reinforcing rib, 22. water inlet flow channel, 23. water outlet flow channel, 24. connecting flow channel a, 25. gap flow channel, 26. docking flow channel a, 27. docking flow channel b, 28. connecting flow channel b, 29. dilute water chamber, 30. concentrated water chamber. DETAILED DESCRIPTION

[0038] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0039] The components of the embodiments of the present invention generally described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention.

[0040] Based on the embodiments of the present utility model, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present utility model.

[0041] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. It should also be noted that, for ease of description, only the parts related to the utility model are shown in the drawings.

[0044] Example: Reference Figure 1-8 The device for dispersing and reducing the scale and concentration of desulfurized wastewater anions shown in the figure comprises a plurality of anion screening membranes 14, anti-pollution cation membranes 15 and partitions. The anion screening membranes 14 and the anti-pollution cation membranes 15 are alternately stacked to form a dispersion unit. Adjacent anion screening membranes 14 and anti-pollution cation membranes 15 are separated from each other by partitions and alternately form a fresh water chamber 29 and a concentrated water chamber 30. The partition is a plate-frame structure, and a partition net 20 is fixed inside the partition. The thickness of the partition net 20 is less than that of the partition. The partition plays the role of supporting the screening membrane and forming a water chamber. There are three dispersion units, which are a primary dispersion unit, an enrichment unit and a secondary dispersion unit. The three dispersion units are used for electrodialysis concentration of desulfurized wastewater at different stages. A cathode plate a1 is provided on the top of the first-stage dispersion unit, an anode plate a2 is provided between the first-stage dispersion unit and the enrichment unit, a cathode plate b3 is provided between the enrichment unit and the second-stage dispersion unit, and an anode plate b4 is provided at the bottom of the second-stage dispersion unit. The three dispersion units are fixedly connected to the cathode plate a1, the anode plate a2, the cathode plate b3 and the anode plate b4 by a plurality of fasteners. The plurality of fasteners are evenly distributed according to equal torque and press and fix the three dispersion units to the cathode plate a1, the anode plate a2, the cathode plate b3 and the anode plate b4;

[0045] A water inlet channel 22 and a water outlet channel 23 are provided in a plurality of partitions, and a plurality of slit channels 25 are provided on both inner sides of the partitions, and the water inlet channel 22 and the water outlet channel 23 are both connected with the slit channels 25; the desulfurized wastewater is pumped into the water inlet channel 22 by an external circulation pump, and then flows into the partition frame chamber through the slit channel 25. The desulfurized wastewater entering the frame chamber flows toward the side of the water outlet channel 23, and enters the water outlet channel 23 through the slit channel 25 again and is discharged, thus forming a cycle. The desulfurized wastewater will flush the anion screening membrane 14 and the anti-pollution cation membrane 15 during its flow in the frame chamber, thereby promoting the mixing of the water flow and reducing the scaling tendency of the anion screening membrane 14 and the anti-pollution cation membrane 15, thereby ensuring the stable electrodialysis concentration of the desulfurized wastewater by the device.

[0046] The plurality of partitions are composed of a top dilute chamber partition 7, a top concentrated chamber partition 10, a bottom dilute chamber partition 18, a bottom concentrated chamber partition 19 and a plurality of middle partitions, and the plurality of middle partitions are composed of a plurality of middle dilute chamber partitions 16 and middle concentrated chamber partitions 17 of the same structure, and the middle dilute chamber partitions 16 and the middle concentrated chamber partitions 17 are alternately stacked;

[0047] The internal frame chambers of the top dilute chamber partition 7, the middle dilute chamber partition 16 and the bottom dilute chamber partition 18 are all fresh water chambers 29, and a plurality of fresh water chambers 29 are circulated and connected through a group of internal flow channels. The internal frame chambers of the top concentrated chamber partition 10, the middle concentrated chamber partition 17 and the bottom concentrated chamber partition 19 are all concentrated water chambers 30, and a plurality of concentrated water chambers 30 are circulated and connected through another group of internal flow channels.

[0048] Each dispersion unit and the plates at both ends thereof constitute an electrodialysis device, which is electrically connected to the two poles of direct current to form a direct current electric field. The desulfurized wastewater is distributed in proportion and enters the top dilute chamber partition 7 and the top concentrated chamber partition 10 respectively. The wastewater entering the top dilute chamber partition 7 is evenly dispersed to a number of middle dilute chamber partitions 16 and the bottom dilute chamber partition 18 through the internal flow channel and circulates. The wastewater entering the top concentrated chamber partition 10 is evenly dispersed to a number of middle concentrated chamber partitions 17 and the bottom concentrated chamber partition 19 through the internal flow channel and circulates. Under the joint action of the direct current electric field, the anion screening membrane 14 and the anti-pollution cation membrane 15, the ions in the concentrated water chamber 30 basically do not migrate, while the cations in the dilute water chamber 29 pass through the anti-pollution cation membrane 15 and enter an adjacent concentrated water chamber 30, and the monovalent anions in the dilute water chamber 29 pass through the anion screening membrane 14 and enter another adjacent concentrated water chamber 30, thereby realizing efficient electrodialysis concentration of the desulfurized wastewater.

[0049] The anti-pollution cation membrane 15 only allows cations to pass through, and the anion screening membrane 14 only allows monovalent anions to pass through. The main monovalent anions that pass through the device are chloride ions.

[0050] As for the specific structure and connection method of the internal flow channels, in the present embodiment, the two groups of internal flow channels include two groups of connecting flow channels a24, two groups of connecting flow channels b28 and several groups of docking flow channels a26 and docking flow channels b27 which are opened on different partitions, and the connecting flow channels a24, docking flow channels a26, docking flow channels b27 and connecting flow channels b28 in each internal flow channel are vertically connected, the two groups of connecting flow channels a24 are respectively opened on the lower surfaces of the top dilute chamber partition 7 and the top concentrated chamber partition 10, the top dilute chamber partition 7 is stacked on the top of the top concentrated chamber partition 10, the water inlet flow channel 22 and the water outlet flow channel 23 are both connected to the connecting flow channels a24, one group of docking flow channels b27 is opened on the upper surface of the top concentrated chamber partition 10, and the group of docking flow channels b27 is connected to a group of connecting flow channels a24 on the top dilute chamber partition 7, and one side of the top dilute chamber partition 7 is fixedly connected to The liquid inlet a8 and the liquid outlet a9 are connected to the water inlet channel 22 and the water outlet channel 23 respectively. The liquid inlet b11 and the liquid outlet b12 are fixedly connected on one side of the top concentration chamber partition 10. The liquid inlet b11 and the liquid outlet b12 are connected to the water inlet channel 22 and the water outlet channel 23 respectively. Several groups of docking channels a26 and docking channels b27 are respectively opened on the middle partition. The water inlet channel 22 and the water outlet channel 23 in the middle partition are both connected to the docking channel a26. The docking channel a26 on the adjacent middle partition is connected to the docking channel b27. Two groups of connecting channels b28 are respectively opened on the upper surfaces of the bottom dilute chamber partition 18 and the bottom concentration chamber partition 19. One group of docking channels b27 is opened on the upper surface of the bottom concentration chamber partition 19. The docking channel b27 is connected to the connecting channel b28 on the bottom dilute chamber partition 18.

[0051] The specific water inlet route of desulfurization wastewater can be referred to Fig. 9 As indicated by the middle arrow, the fresh water inlet route of the electrodialysis fresh water chamber 29 is to enter the water inlet channel 22 from the liquid inlet a8 and flow downward through the connecting channel a24, the docking channel b27 and the docking channel a26 and be diverted into the water inlet channel 22 in the middle fresh water chamber partition 16, and finally enter the water inlet channel 22 in the bottom fresh water chamber partition 18 through the connecting channel b28, so that the electrodialysis fresh water is evenly distributed into the fresh water chamber 29 and enters the water outlet channel 23, and finally rises vertically through another connecting channel b28, the docking channel b27, the docking channel a26 and the connecting channel a24 in turn and converges to the liquid outlet a9, and is discharged through the liquid outlet a9 to form an internal circulation.

[0052] The inlet and outlet routes of the fresh water in the electrodialysis concentrated water chamber 30 are the same as the inlet and outlet routes of the fresh water.

[0053] The circulation connection among the water inlet channel 22, the water outlet channel 23, the gap channel 25 and the internal channels enables the desulfurization wastewater to be evenly distributed in the concentrated water chamber 30 and the fresh water chamber 29, ensuring that the water quality in each frame chamber is evenly mixed, so that the water flow can flush the anti-pollution cation membrane 15 and the anion screening membrane 14 with greater force, promoting the mixing of the water flow while reducing the scaling tendency of the anti-pollution cation membrane 15 and the anion screening membrane 14, ensuring the stable dispersion and concentration of the desulfurization wastewater by the device.

[0054] In order to avoid increasing the structural strength of the partition 20 and enhance the turbulence on the surface of the partition 20, in this embodiment, the partition is a thermoplastic elastic plate frame, and a plurality of reinforcing ribs 21 are provided inside the partition 20. The partition 20 is a diamond grid structure, and the thickness of the reinforcing ribs 21 is 1-1.05 times the thickness of the partition 20. The reinforcing ribs 21 divide the partition 20 into a plurality of upward and downward convection channels, so that the water flows downward in the convection channels, thereby increasing the turbulence of the liquid. When the thickness of the reinforcing ribs 21 is higher than the thickness of the partition 20, the turbulence generated when the liquid flows is further increased due to the obstruction of the water flow by the reinforcing ribs 21, so that the anti-pollution cation membrane 15 and the anion screening membrane 14 as well as the partition 20 can be washed by the larger turbulence, thereby preventing the liquid from being deposited on the surface of the partition 20, and further reducing the scaling tendency of the anti-pollution cation membrane 15 and the anion screening membrane 14.

[0055] In this embodiment, the specific structure of the fastener includes a fastening screw 5 and a nut. The threaded end of the fastening screw 5 sequentially passes through the cathode plate a1, the primary dispersion unit, the anode plate a2, the enrichment unit, the cathode plate b3, the secondary dispersion unit and the anode plate b4 and cooperates with the nut thread. The four corners of the lower surface of the anode plate b4 are fixedly installed with insulating supports 6. The device is used according to Figure 1 The method shown is to install vertically and fix it in a suitable position by an insulating support 6;

[0056] In addition, since the device needs to calculate the required desalination salt charge equivalent according to the water quality of the desulfurization wastewater, the scale of the desulfurization wastewater to be treated, and the required concentration multiple in actual use, the required number of anti-pollution cation membranes 15 and anion screening membranes 14 are calculated according to the charge equivalent, and the primary dispersion unit, the secondary dispersion unit and the enrichment unit all need to be calculated according to the working conditions, the device needs to be assembled and debugged when used. The structure of the fastener is simple, which facilitates the assembly of each dispersion unit.

[0057] In order to prevent the slurry from forming deposits on the surface of the partition 20 and further reduce the scaling tendency of the anti-pollution cation membrane and the anion screening membrane, in the present embodiment, a plurality of slit channels 25 are divided into two groups, the two groups of slit channels 25 are separated by the partition 20, and the two groups of slit channels 25 are staggered, and each group of slit channels 25 is arranged equidistantly along a straight line on the inner side of the partition. The staggered distribution of the upper and lower groups of slit channels 25 causes the desulfurization wastewater to form multiple streams of water in the frame chamber during the process of being discharged or entering through the two groups of slit channels 25, and the collision of the multiple streams of water will form stronger turbulence.

[0058] In order to avoid scaling on the electrode plates and improve the screening effect of the anion screening membrane 14 on chloride ions, in this embodiment, the anion screening membrane 14 is a modified sulfonated polyetheretherketone ion membrane equipped with grafted ionic organic functional groups, and an electrode water chamber 13 is provided on the lower surface of the cathode plate a1 and the upper surface of the anode plate b4. The upper and lower surfaces of the anode plate a2 and the cathode plate b3 are both provided with the same electrode water chamber 13, and the interior of the electrode water chamber 13 is configured with brine.

[0059] The electrode plate is separated from the partition by the electrode water chamber 13, and the electrode water chamber 13 is separated from the adjacent partition by the electrode membrane. The accumulated water is configured into a salt water with a certain concentration using ordinary sodium chloride solution. The salt water is configured in the electrode chamber mainly to provide charge migration conditions for the DC electric field. Ordinary salt solution does not have scaling ions such as Ca2+, Mg2+, SO42-, etc., thus avoiding the occurrence of plate scaling.

[0060] The sulfonated polyetheretherketone ion membrane equipped with grafted ionic organic functional groups has an efficient screening effect on chloride ions, but it needs to be subjected to interface modification when used in this device. The interface modification process is as follows: first, it is immersed in deionized water for 30 minutes to make it swell, in order to prevent local swelling of the base membrane after contacting with water during the modification process. It is placed in a modification tank, and the organic phase solution is poured in for 1 hour, then the solution is poured out, and left to cool at room temperature. Subsequently, the aqueous phase solution is poured into the mold, poured out after sufficient reaction, and dried at room temperature for 30 minutes. The membrane is taken out of the mold and placed in a 60°C oven to dry for 2 hours to obtain the desired anion screening membrane 14.

[0061] refer to Fig.10 As shown, the specific workflow of the utility model is:

[0062] Step 1: Preliminarily perform sedimentation, filtration and other treatment processes on the desulfurization wastewater to make the suspended solids in the desulfurization wastewater ≤1mg / L; then determine the concentration multiple required according to the water quality of the desulfurization wastewater, and distribute the desulfurization wastewater in proportion according to the concentration multiple, or adjust and distribute it to the pre-set fresh water tank and concentrated water tank according to the working conditions, connect the outlet of the fresh water tank with the liquid inlet a8 on the primary dispersion unit through a pipeline, and then connect the water inlet of the fresh water tank with the liquid outlet a9 on the primary dispersion unit through a pipeline, and install a water pump on the pipeline to circulate the desulfurization wastewater to be dispersed between the fresh water chamber 29 of the primary dispersion unit and the fresh water tank; then connect the outlet of the concentrated water tank with the liquid outlet a9 on the primary dispersion unit through a pipeline. The liquid inlet b11 is connected, and then the water inlet of the fresh water tank is connected to the liquid outlet b12 on the primary dispersion unit through a pipeline. A water pump is installed on the pipeline to allow the desulfurization wastewater to be concentrated to circulate between the concentrate chamber 30 of the primary dispersion unit and the concentrate tank; the alternating current is converted into stable direct current through a rectifier, and the cathode plate a1 and the anode plate a2 are electrically connected to the two poles of the direct current, so that the primary dispersion unit forms a stable direct current electric field. After a certain period of time, the TDS content of the concentrate tank and the chloride ion content of the fresh water tank are respectively detected. When the TDS content in the concentrate reaches 80000-100000 mg / L and the chloride ion content in the fresh water is less than 1000 mg / L, the dispersion can be stopped and the DC electric field can be removed.

[0063] Step 2: Determine the concentration multiple required again according to the water quality of the primary fresh water obtained by electrodialysis in step 1, distribute the primary fresh water obtained by electrodialysis in proportion according to the concentration multiple, and introduce the distributed primary fresh water into the fresh water chamber 29 and the concentrated water chamber 30 of the secondary dispersion unit respectively according to step S2 and circulate; connect the cathode plate b3 and the anode plate b4 to the two poles of the direct current so that the secondary dispersion unit forms a stable direct current electric field, and concentrate the primary fresh water. After a certain period of time, detect the TDS and chloride ion content in the fresh water in the fresh water chamber 29 of the secondary dispersion unit. When the chloride ion content in the fresh water is less than 100 mg / L and the TDS is less than 1000 mg / L, the secondary dispersion is completed and the direct current field is removed; connect the qualified fresh water obtained in S5 to the wet flue gas desulfurization system and use it as desulfurized water, and mix the concentrated water with the concentrated water in S3;

[0064] This step is implemented because the chloride ion content in the primary fresh water obtained by electrodialysis in the first-stage dispersion unit is still relatively high, and secondary separation and concentration are required to further screen out the chloride ions.

[0065] Step 3: Determine the concentration multiple according to the water quality of the mixed concentrated water obtained in step 2, distribute the mixed concentrated water according to the concentration multiple, and respectively pass the distributed mixed concentrated water into the fresh water chamber 29 and the concentrated water chamber 30 of the enrichment unit according to step S2 and circulate; connect the anode plate a2 and the cathode plate b3 to the two poles of the direct current, so that the enrichment unit forms a stable direct current electric field, and further concentrates and enriches the concentrated concentrated water. After a certain period of time, detect the TDS (total dissolved solids) in the electrodialysis concentrated water in the enrichment unit. When the TDS of the concentrated water reaches the target value, remove the electric field, the enrichment and concentration is completed, and the generated fresh water is connected to the wet flue gas desulfurization system for use as desulfurized water, and the concentrated water after the secondary concentration enters the next treatment link;

[0066] In this step, the mixed concentrate obtained in S6 can be concentrated and enriched again because the SO42- concentration in the concentrate produced by electrodialysis concentration in the primary dispersion unit and the secondary dispersion unit is similar to the content of the initial desulfurization wastewater. The SO42- content in the mixed concentrate cannot form a physical and chemical environment that satisfies the crystallization of sulfate, thereby curbing the formation of sulfate crystals and avoiding the precipitation of a large amount of sulfate crystals. Therefore, it can be further enriched and concentrated, thereby further improving the concentration multiple of the desulfurization wastewater.

[0067] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the utility model involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the concept of the utility model. For example, the above features are replaced with the technical features with similar functions disclosed in the present application (but not limited to) by each other to form a technical solution.

[0068] Except for the technical features described in the specification, the other technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present utility model, the other technical features will not be described in detail here.

Claims

1. A desulfurization wastewater anion dispersion scale reduction and concentration device, comprising a plurality of anion screening membranes (14), anti-pollution cation membranes (15) and partitions, wherein the anion screening membranes (14) and the anti-pollution cation membranes (15) are alternately stacked to form a dispersion unit, and adjacent anion screening membranes (14) and anti-pollution cation membranes (15) are separated from each other by partitions and alternately form fresh water chambers (29) and concentrated water chambers (30), wherein the partitions are of a plate-frame structure and a partition net (20) is fixed inside the partitions, characterized in that: The number of the dispersion units is three and they are a primary dispersion unit, an enrichment unit and a secondary dispersion unit, a cathode plate a (1) is provided on the top of the primary dispersion unit, an anode plate a (2) is provided between the primary dispersion unit and the enrichment unit, a cathode plate b (3) is provided between the enrichment unit and the secondary dispersion unit, and an anode plate b (4) is provided at the bottom of the secondary dispersion unit, and the three dispersion units are fixedly connected to the cathode plate a (1), the anode plate a (2), the cathode plate b (3) and the anode plate b (4) by a plurality of fasteners; A water inlet flow channel (22) and a water outlet flow channel (23) are provided in each of the plurality of partitions, and a plurality of slit flow channels (25) are provided on both inner side surfaces of the partitions, and the water inlet flow channels (22) and the water outlet flow channels (23) are both connected to the slit flow channels (25); The plurality of partitions are composed of a top dilute chamber partition (7), a top concentrated chamber partition (10), a bottom dilute chamber partition (18), a bottom concentrated chamber partition (19), and a plurality of middle partitions; the plurality of middle partitions are composed of a plurality of middle dilute chamber partitions (16) and middle concentrated chamber partitions (17) having the same structure; and the plurality of middle dilute chamber partitions (16) and middle concentrated chamber partitions (17) are alternately stacked; The internal frame chambers of the top dilute chamber partition (7), the middle dilute chamber partition (16) and the bottom dilute chamber partition (18) are all dilute water chambers (29), and a plurality of the dilute water chambers (29) are cyclically connected via a group of internal flow channels. The internal frame chambers of the top concentrated chamber partition (10), the middle concentrated chamber partition (17) and the bottom concentrated chamber partition (19) are all concentrated water chambers (30), and a plurality of the concentrated water chambers (30) are cyclically connected via another group of internal flow channels.

2. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 1 is characterized in that: The two groups of internal flow channels include two groups of connecting flow channels a (24), two groups of connecting flow channels b (28) and a plurality of groups of docking flow channels a (26) and docking flow channels b (27) which are opened on different partitions, and the connecting flow channels a (24), docking flow channels a (26), docking flow channels b (27) and connecting flow channels b (28) in each internal flow channel are vertically connected.

3. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 2 is characterized in that: The two groups of connecting flow channels a (24) are respectively provided on the lower surface of the top dilute chamber partition (7) and the top concentrated chamber partition (10); the top dilute chamber partition (7) is stacked on the top of the top concentrated chamber partition (10); the water inlet flow channel (22) and the water outlet flow channel (23) are both connected to the connecting flow channel a (24); and a group of docking flow channels b (27) is provided on the upper surface of the top concentrated chamber partition (10); the docking flow channels b (27) are connected to a group of connecting flow channels a (24) on the top dilute chamber partition (7); A liquid inlet a (8) and a liquid outlet a (9) are fixedly connected on one side of the top dilute chamber partition (7), and the liquid inlet a (8) and the liquid outlet a (9) are respectively connected to the water inlet flow channel (22) and the water outlet flow channel (23). A liquid inlet b (11) and a liquid outlet b (12) are fixedly connected on one side of the top concentrated chamber partition (10), and the liquid inlet b (11) and the liquid outlet b (12) are respectively connected to the water inlet flow channel (22) and the water outlet flow channel (23).

4. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 3 is characterized in that: A plurality of groups of the docking flow channels a (26) and the docking flow channels b (27) are respectively arranged on the middle partition, the water inlet flow channel (22) and the water outlet flow channel (23) in the middle partition are both connected to the docking flow channel a (26), and the docking flow channels a (26) and the docking flow channels b (27) on adjacent middle partitions are connected.

5. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 4 is characterized in that: The two groups of connecting flow channels b (28) are respectively opened on the upper surface of the bottom dilute chamber partition (18) and the bottom concentrated chamber partition (19), and one group of docking flow channels b (27) is opened on the upper surface of the bottom concentrated chamber partition (19), and the docking flow channels b (27) are connected to the connecting flow channels b (28) on the bottom dilute chamber partition (18).

6. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 1, characterized in that: The partition plate is a thermoplastic elastic plate frame, a plurality of reinforcing ribs (21) are provided inside the partition net (20), the partition net (20) is a diamond grid structure, and the thickness of the reinforcing ribs (21) is 1-1.05 times the thickness of the partition net (20).

7. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 1, characterized in that: The fastener comprises a fastening screw (5) and a nut, wherein the threaded end of the fastening screw (5) sequentially passes through the cathode plate a (1), the primary dispersion unit, the anode plate a (2), the enrichment unit, the cathode plate b (3), the secondary dispersion unit and the anode plate b (4) and is matched with the thread of the nut, and insulating supports (6) are fixedly mounted at the four corners of the lower surface of the anode plate b (4).

8. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 1, characterized in that: The plurality of slit flow channels (25) are divided into two groups, an upper group and an lower group. The two groups of slit flow channels (25) are separated by a partition net (20). The two groups of slit flow channels (25) are staggeredly distributed. Each group of slit flow channels (25) is arranged equidistantly along a straight line on the inner side surface of the partition.

9. The desulfurization wastewater anion dispersion descaling concentration and reduction device according to claim 1, characterized in that: The anion sieving membrane (14) is a modified sulfonated polyetheretherketone ion membrane equipped with grafted ionic organic functional groups. The lower surface of the cathode plate a (1) and the upper surface of the anode plate b (4) are both provided with a polar water chamber (13). The upper and lower surfaces of the anode plate a (2) and the cathode plate b (3) are both provided with the same polar water chamber (13), and salt water is disposed inside the polar water chamber (13).

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