Desulfurization tower waste residue liquid treatment system

Abstract

The utility model discloses a kind of desulfurization tower waste residue liquid processing systems, including the water inlet unit, reaction unit, filtering unit, sludge dewatering unit, dosing unit connected in turn;The reflux line of sludge dewatering unit is also connected with water inlet unit;It further includes water collecting tank unit, and the water collecting tank unit is connected by trench water inlet unit, reaction unit, filtering unit, sludge dewatering unit, water collecting tank unit and the drain of dosing unit.The utility model is linear series through water inlet unit pretreatment (homogeneous adjustment), reaction unit (chemical coagulation), filtering unit (solid-liquid separation), sludge dewatering unit (sludge reduction), dosing unit (reagent accurate dosing), and the process chain of stepwise pollutant removal is formed.

Description

Technical Field

[0001] This utility model belongs to the field of desulfurization tower waste liquid treatment technology, specifically relating to a desulfurization tower waste liquid treatment system. Background Technology

[0002] Inside the desulfurization tower, the desulfurization slurry reacts with the sulfur dioxide gas in the flue gas to achieve desulfurization. After desulfurization, a certain amount of desulfurization waste liquid is generated. The impurities in this waste liquid mainly originate from the flue gas. These impurities enter the desulfurization unit and dissolve in the absorption slurry. Through continuous operation of the desulfurization system, they are gradually concentrated, ultimately resulting in high levels of salts and heavy metals in the desulfurization waste liquid, which poses a serious threat to both production and the environment.

[0003] Currently, the industry commonly uses chemical precipitation methods such as oxidation, neutralization, flocculation, and sedimentation to treat desulfurization wastewater. Chemical precipitation methods have the advantages of simple operation and low operating costs, but they require more equipment, have higher construction investment, and also have many problems in actual operation, such as frequent clogging of the dosing system, poor clarification effect, and instability of diaphragm filter press.

[0004] After treatment using the above methods, pollutants such as suspended solids and heavy metals in the water can be removed to a certain extent. However, the COD, ammonia nitrogen, and dissolved salt content of the system's produced water are still relatively high, which cannot meet the discharge standards or the requirements for entering the enterprise's comprehensive industrial wastewater treatment system. In addition, there are problems such as equipment corrosion, reduced production capacity, and pollution of the workplace environment in the reuse production process that urgently need to be solved.

[0005] It is worth noting that the pollutants in desulfurization wastewater are affected by many factors such as limestone quality, coal type, process water quality, system operation status, and gypsum dewatering effect, resulting in a wide range of water quality variations. In automatic dosing mode, this can lead to waste of reagents or insufficient dosage to achieve the expected results, which is also an important reason for the high cost of existing chemical precipitation treatment. Utility Model Content

[0006] In view of this, the main objective of this utility model is to provide a desulfurization tower waste liquid treatment system.

[0007] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0008] A desulfurization tower waste liquid treatment system includes an inlet unit, a reaction unit, a filtration unit, a sludge dewatering unit, and a chemical dosing unit connected in sequence.

[0009] The return pipeline of the sludge dewatering unit is also connected to the inlet water unit;

[0010] It also includes a water collection tank unit, which is connected to the drainage outlets of the water inlet unit, reaction unit, filtration unit, sludge dewatering unit, water collection tank unit and dosing unit via a trench.

[0011] Preferably, the water inlet unit includes a buffer tank, a sludge pump, a stirrer, and an aeration pipe. The outlet of the sludge pump is connected to the water inlet of the buffer tank via a pipe. The stirrer is vertically installed at the center of the buffer tank. The air outlet of the stirrer is connected to the aeration pipe via an air supply pipe. The aeration pipe is laid flat at the bottom of the buffer tank in a branch pipe structure.

[0012] Preferably, the reaction unit includes a flocculation reaction tank, a sedimentation tank, and a sludge circulation pump; the flocculation reaction tank is connected to the outlet of the buffer tank of the inlet unit via a booster pump, the sedimentation tank is connected to the bottom of the flocculation reaction tank via a gravity weir, the inlet end of the sludge circulation pump is connected to the conical bottom of the sedimentation tank, and the outlet end is connected to the inlet pipe of the flocculation reaction tank via a return pipe.

[0013] Preferably, the flocculation reaction chamber has a circular structure and baffles on its inner wall, and is equipped with a double-layer baffle-type agitator; the double-layer baffle-type agitator vertically penetrates the top cover of the flocculation reaction chamber.

[0014] Preferably, the baffles are welded to the inner wall of the flocculation reaction chamber at a 30° angle, and the distance between adjacent baffles is 40-60cm.

[0015] Preferably, the filtration unit includes a clean water tank, a self-cleaning filter, and an outlet water tank, wherein the self-cleaning filter is disposed between the clean water tank and the outlet water tank.

[0016] The clean water tank is connected to the upper part of the sedimentation tank through an overflow trough; the water pump connected to the clean water tank is connected to the inlet of the self-cleaning filter through a pressure pipeline;

[0017] The outlet of the self-cleaning filter is connected to the water tank.

[0018] Preferably, the sludge dewatering unit includes a diaphragm filter press and a sludge tank, wherein the diaphragm filter press is connected to the sludge tank via a sludge pump;

[0019] The bottom of the sedimentation tank is connected to the sludge tank via a sludge pump, and the sludge tank is connected to the diaphragm filter press via a sludge pressing pump. The diaphragm filter press is also connected to the water collection tank unit.

[0020] Preferably, the dosing unit includes a liquid alkali dosing device, a heavy metal scavenging agent dosing device, a flocculant dosing device, a coagulant aid dosing device, and an oxidant dosing device;

[0021] The liquid alkali dosing device, heavy metal scavenging agent dosing device, flocculant dosing device, coagulant aid dosing device, and oxidant dosing device are respectively connected to the flocculation reaction tank.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] This invention forms a process chain for the removal of pollutants through the linear series connection of the influent pretreatment unit (homogenization adjustment), reaction unit (chemical coagulation), filtration unit (solid-liquid separation), sludge dewatering unit (sludge reduction), and dosing unit (precise dosing of chemicals). Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this invention, illustrate exemplary embodiments of the present invention and, together with their description, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0025] Figure 1 This invention provides a schematic diagram of the structure of a desulfurization tower waste liquid treatment system according to an embodiment of the present invention;

[0026] Figure 2 This invention provides a schematic diagram of the specific structure of the water inlet unit and the reaction unit in a desulfurization tower waste liquid treatment system. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0028] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0029] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, article, or apparatus that includes that element.

[0030] This utility model provides a desulfurization tower waste liquid treatment system, including a water inlet unit, a reaction unit, a filtration unit, a sludge dewatering unit, and a chemical dosing unit connected in sequence.

[0031] The return pipeline of the sludge dewatering unit is also connected to the inlet water unit;

[0032] It also includes a water collection tank unit 5, which is connected to the drainage outlets of the water inlet unit, reaction unit, filtration unit, sludge dewatering unit, water collection tank unit 5 and dosing unit via a trench.

[0033] This invention forms a process chain for the removal of pollutants through the linear series connection of the influent pretreatment unit (homogenization adjustment), reaction unit (chemical coagulation), filtration unit (solid-liquid separation), sludge dewatering unit (sludge reduction), and dosing unit (precise dosing of chemicals).

[0034] This invention treats pollutants such as COD, suspended solids, and heavy metals in a gradient manner, resulting in a high overall removal rate. Each unit has a specialized function (e.g., the reaction unit focuses solely on flocculation), and the total residence time is shortened.

[0035] The water inlet unit includes a buffer tank 101, a sludge pump, a stirrer 102, a stirrer 103, and an aeration pipe 104. The outlet of the sludge pump is connected to the water inlet of the buffer tank 101 through a pipe. The stirrer 102 is vertically installed at the center of the buffer tank 101. The air outlet of the stirrer 103 is connected to the aeration pipe 104 through an air supply pipe. The aeration pipe 104 is laid flat at the bottom of the buffer tank 101 in a branch pipe structure.

[0036] The waste liquid from the desulfurization tower is pumped to buffer tank 101 for pretreatment processes such as homogenization and aeration. This is intended to provide preliminary treatment of the waste liquid from the desulfurization tower to reduce the processing load of subsequent units.

[0037] The buffer tank 101 is made of glass flake anti-corrosion material and is equipped with an aeration pipe 104 in the form of a branch pipe. The air source is provided by a three-lobe agitator 103.

[0038] The aeration pipe 104 serves two purposes: firstly, to minimize the formation of sludge in the buffer tank, and secondly, to perform pre-oxidation to reduce COD in the wastewater and decrease the consumption of subsequent oxidant reagents.

[0039] The reaction unit includes a flocculation reaction tank 201, a sedimentation tank 202, and a sludge circulation pump. The flocculation reaction tank 201 is connected to the outlet of the buffer tank 101 of the inlet unit via a booster pump. The sedimentation tank 202 is connected to the bottom of the flocculation reaction tank 201 via a gravity weir. The inlet end of the sludge circulation pump is connected to the conical bottom of the sedimentation tank 202, and the outlet end is connected to the inlet pipe of the flocculation reaction tank 201 via a return pipe.

[0040] The flocculation reaction chamber 201 has a circular structure and baffles on its inner wall, and is equipped with a double-layer baffle agitator 102; the double-layer baffle agitator 102 penetrates vertically through the top cover of the flocculation reaction chamber 201.

[0041] The flocculation reaction chamber 201 has glass flake anti-corrosion coating.

[0042] The baffles are welded to the inner wall of the flocculation reaction chamber 201 at a 30° angle, and the distance between adjacent baffles is 40-60cm.

[0043] The buffer tank 101 is connected to the flocculation reaction tank 201 via a first butterfly valve 1011, a first pump body 1012, a first check valve 1013, and a second butterfly valve 1014; and via a third butterfly valve 1015, a second pump body 1016, a second check valve 107, and a fourth butterfly valve 1018, thus realizing the main and backup switching. During normal operation, only the main line is opened, and the backup branch line is kept closed; when the pump body of the main line is being maintained, the system switches to the backup branch line.

[0044] The filtration unit includes a clean water tank 301, a self-cleaning filter 302, and an outlet water tank 303, wherein the self-cleaning filter 302 is disposed between the clean water tank and the outlet water tank.

[0045] The clean water tank 301 is connected to the upper part of the sedimentation tank through an overflow trough; the water pump connected to the clean water tank 301 is connected to the inlet of the self-cleaning filter 302 through a pressure pipe.

[0046] The outlet of the self-cleaning filter 302 is connected to the water tank 303.

[0047] The sludge dewatering unit includes a diaphragm filter press 401 and a sludge tank 402. The diaphragm filter press 401 is connected to the sludge tank via a sludge pump 403.

[0048] The bottom of the sedimentation tank 202 is connected to the sludge tank 402 via a sludge pump. The sludge tank 402 is connected to the diaphragm filter press 401 via a sludge pressing pump. The diaphragm filter press 401 is also connected to the water collection tank unit 5.

[0049] After pretreatment, the waste liquid is pumped to the flocculation reaction tank 201. A continuous treatment process involving chemical dosing of alkali, flocculant, and coagulant aid, along with contact sludge, is employed to complete both neutralization and coagulation reactions in a single step. After the reaction, the waste liquid flows by gravity from the flocculation reaction tank 201 into the sedimentation tank 202. The flocculants in the wastewater are deposited at the bottom of the sedimentation tank 202 by gravity, concentrating into sludge, which is then removed by a sludge scraper. The clear water rises to the top and flows by gravity through a ring-shaped triangular overflow weir to the clear water tank.

[0050] The sludge returned from the bottom of sedimentation tank 202 is thoroughly mixed with the raw water, thereby enhancing the contact and adsorption between solid particles in the water, forming good flocculation, and accelerating the reaction and sedimentation rate. A sludge circulation pump is installed to pump the sediment from the bottom of the reaction tank outlet to the reaction tank inlet for circulation treatment. This design allows the sludge deposited at the bottom of the reaction tank to flow, thus minimizing the problem of easy pipe blockage and further promoting the reaction and sedimentation rate.

[0051] The dosing unit includes a liquid alkali dosing device 501, a heavy metal scavenger dosing device 502, a flocculant dosing device 503, a coagulant aid dosing device 504, and an oxidant dosing device 505.

[0052] The liquid alkali dosing device 501, heavy metal scavenging agent dosing device 502, flocculant dosing device 503, coagulant aid dosing device 504, and oxidant dosing device 505 are respectively connected to the flocculation reaction tank 201.

[0053] Different agents are added at the inlets of the two water tanks, which can promote uniform mixing of the agents by means of water flow.

[0054] The liquid alkali dosing device 501, heavy metal scavenging agent dosing device 502, flocculant dosing device 503, coagulant aid dosing device 504, and oxidant dosing device 505 are respectively installed at different sections of the inlet of the flocculation reaction tank 201, and the agents are mixed evenly by means of water flow.

[0055] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A desulfurization tower waste liquid treatment system, characterized in that, It includes an inlet unit, a reaction unit, a filtration unit, a sludge dewatering unit, and a chemical dosing unit connected in sequence; The return pipeline of the sludge dewatering unit is also connected to the inlet water unit; It also includes a water collection tank unit, which is connected to the drainage outlets of the water inlet unit, reaction unit, filtration unit, sludge dewatering unit, water collection tank unit and dosing unit via a trench.

2. The desulfurization tower waste liquid treatment system according to claim 1, characterized in that, The water inlet unit includes a buffer tank, a sludge pump, a stirrer, and an aeration pipe. The outlet of the sludge pump is connected to the water inlet of the buffer tank through a pipe. The stirrer is vertically installed at the center of the buffer tank. The air outlet of the stirrer is connected to the aeration pipe through an air supply pipe. The aeration pipe is laid flat at the bottom of the buffer tank in a branch pipe structure.

3. The desulfurization tower waste liquid treatment system according to claim 1 or 2, characterized in that, The reaction unit includes a flocculation reaction tank, a sedimentation tank, and a sludge circulation pump. The flocculation reaction tank is connected to the outlet of the buffer tank of the inlet unit via a booster pump. The sedimentation tank is connected to the bottom of the flocculation reaction tank via a gravity weir. The inlet end of the sludge circulation pump is connected to the conical bottom of the sedimentation tank, and the outlet end is connected to the inlet pipe of the flocculation reaction tank via a return pipe.

4. The desulfurization tower waste liquid treatment system according to claim 3, characterized in that, The flocculation reaction chamber has a circular structure and baffles on its inner wall, and is equipped with a double-layer baffle-type agitator; the double-layer baffle-type agitator vertically penetrates the top cover of the flocculation reaction chamber.

5. The desulfurization tower waste liquid treatment system according to claim 4, characterized in that, The baffles are welded to the inner wall of the flocculation reaction chamber at a 30° angle, and the distance between adjacent baffles is 40-60cm.

6. The desulfurization tower waste liquid treatment system according to claim 5, characterized in that, The filtration unit includes a clean water tank, a self-cleaning filter, and an outlet water tank, with the self-cleaning filter disposed between the clean water tank and the outlet water tank; The clean water tank is connected to the upper part of the sedimentation tank through an overflow trough; the water pump connected to the clean water tank is connected to the inlet of the self-cleaning filter through a pressure pipeline; The outlet of the self-cleaning filter is connected to the water tank.

7. The desulfurization tower waste liquid treatment system according to claim 6, characterized in that, The sludge dewatering unit includes a diaphragm filter press and a sludge tank, and the diaphragm filter press is connected to the sludge tank via a sludge pump. The bottom of the sedimentation tank is connected to the sludge tank via a sludge pump, and the sludge tank is connected to the diaphragm filter press via a sludge pressing pump. The diaphragm filter press is also connected to the water collection tank unit.

8. The desulfurization tower waste liquid treatment system according to claim 7, characterized in that, The dosing unit includes a liquid alkali dosing device, a heavy metal scavenger dosing device, a flocculant dosing device, a coagulant aid dosing device, and an oxidant dosing device. The liquid alkali dosing device, heavy metal scavenging agent dosing device, flocculant dosing device, coagulant aid dosing device, and oxidant dosing device are respectively connected to the flocculation reaction tank.

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