Sewage sedimentation tank for effectively treating desulfurization wastewater
By combining a primary sedimentation tank, a coagulation tank, a pH adjustment tank, and a high-density sedimentation tank in the treatment system, the problems of high heavy metals and turbidity in desulfurization wastewater were solved, achieving the effects of heavy metal removal and turbidity reduction.
Patent Information
- Application Number
- CN202520489085.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-20
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-03-20
AI Technical Summary
The desulfurization wastewater contains a large amount of heavy metals and has high turbidity, which affects its use.
The system employs a combination of primary sedimentation tank, coagulation tank, pH adjustment tank, and high-density sedimentation tank. Heavy metals are removed by adding TMT-15 agent, suspended particles are destabilized by using PAC or polyferric sulfate as coagulants, the pH value is adjusted by adding sodium hydroxide solution, and then PAM is added to form large flocs that settle in the high-density sedimentation tank. Finally, the sludge is discharged.
It effectively reduces heavy metals in desulfurization wastewater, lowers turbidity, and ensures that the water quality meets usage requirements.
Smart Images
Figure CN223936309U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of wastewater treatment technology, specifically to a wastewater sedimentation tank for effectively treating desulfurization wastewater. Background Technology
[0002] Our company currently has a tail gas desulfurization unit, which adopts the classic wet desulfurization method (limestone-gypsum method). The raw material added is lime slurry, which is sprayed downwards through nozzles inside the desulfurization tower. It reacts with the flue gas rising from the bottom to generate calcium sulfate, calcium sulfite, and nitrogen oxides. After being aerated by an aeration fan at the bottom of the desulfurization tower, the slurry converts sulfite into sulfate. The slurry is then pumped into a high-level hydrocyclone separator. The easily deposited gypsum is separated by the hydrocyclone separator and then enters a dewatering machine for dehydration and drying. The remaining muddy water enters a wastewater tank and is then pumped to other places for recycling.
[0003] However, after a period of operation, it was found that the wastewater pumped into other water usage areas contained large amounts of heavy metals and had high turbidity, affecting its use. Therefore, the applicant developed a new technical solution during actual production to solve the above-mentioned technical problems. Utility Model Content
[0004] The purpose of this invention is to provide a wastewater sedimentation tank for effectively treating desulfurization wastewater, which has the advantages of reducing heavy metals and turbidity in the desulfurization wastewater.
[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:
[0006] This utility model provides a wastewater sedimentation tank for effectively treating desulfurization wastewater, including a primary sedimentation tank and a high-density sedimentation tank set on the ground, and a coagulation tank, a flocculation tank and a pH adjustment tank arranged in a straight line between the primary sedimentation tank and the high-density sedimentation tank. The initial effluent pipe of the primary sedimentation tank is connected to the coagulation tank, the coagulation tank is connected to the pH adjustment tank through a connecting component, the pH adjustment tank is connected to the flocculation tank through a return pipe, and the upper end of the flocculation tank has a notch that connects to the high-density sedimentation tank.
[0007] Both the primary sedimentation tank and the high-density sedimentation tank are equipped with sludge scrapers and effluent weirs on the upper part of their inner walls. The primary sedimentation tank has an inlet pipe on one side, and the high-density sedimentation tank has a drain pipe at the upper part that corresponds to the effluent weir.
[0008] By adopting the above technical solution, TMT-15 reagent is added to the primary sedimentation tank to remove heavy metals such as lead, copper, and mercury. The settled sludge is discharged from the sludge discharge hole at the bottom of the primary sedimentation tank to the sludge tank. The clearer water is collected from the upper effluent weir plate of the primary sedimentation tank and enters the coagulation tank through the initial effluent pipe. The coagulant added to the coagulation tank is generally PAC or polyferric sulfate, the main function of which is to destabilize the suspended particles, that is, to make them lose stability. Then, the wastewater is passed to the pH adjustment tank through the connecting pipe. Sodium hydroxide solution is added to the pH adjustment tank, firstly to increase the pH value of the wastewater, and secondly to remove water. The medium-sized part temporarily hardens and is then fed into the flocculation tank. PAM flocculant is added to the flocculation tank, which generates suspended particles. Under the adsorption bridging effect of PAM, these particles aggregate to form large flocs that are easy to settle. The large flocs slowly enter the high-density sedimentation tank with the water flow, which avoids damage to the flocs. The large flocs settle in the high-density sedimentation tank and are finally discharged into the sludge tank through the sludge discharge hole at the bottom of the high-density sedimentation tank. The clear liquid on the upper layer of the high-density sedimentation tank is collected through the effluent weir and discharged through the drain pipe. This achieves the purpose of reducing heavy metals and lowering turbidity in desulfurization wastewater.
[0009] Preferably, the upper walls of the coagulation tank, flocculation tank and pH adjustment tank are provided with crossbeams, and the crossbeams are respectively provided with stirring shafts for stirring in the coagulation tank, flocculation tank and pH adjustment tank. Each stirring shaft has a number of stirring blades on its outer wall.
[0010] Preferably, a guide tube is provided on the wall of the flocculation tank via horizontally distributed connecting rods. The guide tube is open at the top and bottom. The stirring shaft and stirring blades of the flocculation tank are both inserted inside the guide tube. The return pipe is provided on the lower wall of the flocculation tank, with one end connected to the pH adjustment tank and the other end bent upwards into the guide tube.
[0011] Preferably, the initial outlet pipe is connected to a guide pipe extending downward into the coagulation tank via a flange, and the guide pipe is located on one side of the stirring shaft in the coagulation tank.
[0012] Preferably, the high-density sedimentation tank has buffer plates distributed towards the gap on its tank wall. The buffer plates are set on the opposite tank wall of the high-density sedimentation tank, and the lower end of the buffer plates has an inclined plate that gradually slopes away from the gap. The lower end of the inclined plate has a vertical plate. Both ends of the inclined plate and the vertical plate are connected to the tank wall of the high-density sedimentation tank. The lower end of the vertical plate is located above the scraper blade of the sludge scraper.
[0013] Preferably, the connecting component includes a connecting pipe disposed between the coagulation tank and the pH adjustment tank, with both ends of the connecting pipe connected to the upper tank walls of the coagulation tank and the pH adjustment tank respectively, and spanning across the flocculation tank.
[0014] Preferably, the bottom of the primary sedimentation tank and the high-density sedimentation tank are supported by several columns, and the bottom of the primary sedimentation tank and the high-density sedimentation tank are provided with sludge discharge holes. The two ends of the coagulation tank, the flocculation tank and the pH adjustment tank are respectively fixed to the outer walls of the primary sedimentation tank and the high-density sedimentation tank. The bottom of the coagulation tank, the flocculation tank and the pH adjustment tank are provided with vent pipes, and each of the vent pipes is provided with a shut-off valve.
[0015] Preferably, both the primary sedimentation tank and the high-density sedimentation tank are provided with maintenance manholes on opposite sides. The maintenance manholes are sealed by a sealing plate, which is detachably connected to the wall of the maintenance manhole by bolts.
[0016] The beneficial effects of this invention are as follows: TMT-15 reagent is added to the primary sedimentation tank to remove heavy metals such as lead, copper, and mercury. The settled sludge is discharged from the sludge discharge hole at the bottom of the primary sedimentation tank into the sludge tank. The clearer water is collected from the upper effluent weir plate of the primary sedimentation tank and enters the coagulation tank through the initial effluent pipe. The coagulant added to the coagulation tank is generally PAC or polyferric sulfate, whose main function is to destabilize suspended particles, i.e., to destabilize them. Subsequently, the wastewater is passed to the pH adjustment tank through a connecting component. Sodium hydroxide solution is added to the pH adjustment tank, firstly to increase the pH value of the wastewater, and secondly to remove... The water undergoes temporary hardening and is then introduced into a flocculation tank. PAM (particulate organic matter) flocculant is added, generating suspended particles that aggregate under the adsorption bridging effect of PAM to form large, easily settling flocs. These large flocs slowly flow into a high-density sedimentation tank, preventing damage to the flocs. The large flocs settle in the high-density sedimentation tank and are finally discharged into a sludge tank through the sludge discharge hole at the bottom of the tank. The clear liquid at the top of the high-density sedimentation tank is collected by the effluent weir and discharged through a drain pipe. This process effectively reduces heavy metals and turbidity in the desulfurization wastewater. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 This is a schematic diagram of the structure of this embodiment;
[0019] Figure 2 for Figure 1 A top-view structural diagram;
[0020] Figure 3 This is a schematic diagram illustrating the structure of the guide tube in this embodiment.
[0021] Explanation of reference numerals in the attached figures:
[0022] In the diagram: 1. Primary sedimentation tank; 11. Initial effluent pipe; 12. Inlet pipe; 13. Guide pipe; 14. Column; 15. Sludge discharge hole; 2. High-density sedimentation tank; 21. Coagulation tank; 211. Vent pipe; 22. Flocculation tank; 221. Notch; 23. pH adjustment tank; 24. Return pipe; 25. Sludge scraper; 251. Effluent weir plate; 26. Drainage pipe; 27. Crossbeam; 271. Agitator shaft; 272. Agitator blades; 28. Guide cylinder; 29. Buffer plate; 291. Inclined plate; 292. Vertical plate; 293. Connecting pipe; 294. Inspection manhole pipe. Detailed Implementation
[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0024] An effective wastewater sedimentation tank for treating desulfurization wastewater, such as Figure 1 and Figure 2 It includes a primary sedimentation tank 1 and a high-density sedimentation tank 2 set on the ground, and a coagulation tank 21, a flocculation tank 22 and a pH adjustment tank 23 arranged in a straight line between the primary sedimentation tank 1 and the high-density sedimentation tank 2. The primary effluent pipe 11 of the primary sedimentation tank 1 is connected to the coagulation tank 21. The coagulation tank 21 is connected to the pH adjustment tank 23 through a connecting piece. The pH adjustment tank 23 is connected to the flocculation tank 22 through a return pipe 24. A notch 221 is opened on the upper wall of the flocculation tank 22 to connect with the high-density sedimentation tank 2.
[0025] like Figure 1 and Figure 2Both the primary sedimentation tank 1 and the high-density sedimentation tank 2 are equipped with sludge scrapers 25 and effluent weirs 251 on the upper end of their inner walls. The height of the upper end of the effluent weir 251 is lower than the height of the upper opening of the primary sedimentation tank 1 and the high-density sedimentation tank 2. The longitudinal section of the effluent weir 251 is L-shaped. The horizontal part is connected to the tank wall of the primary sedimentation tank 1 and the high-density sedimentation tank 2, and the vertical part is away from the tank wall of the primary sedimentation tank 1 and the high-density sedimentation tank 2. The clear liquid in the primary sedimentation tank 1 and the high-density sedimentation tank 2 overflows over the vertical part of the effluent weir 251 and accumulates in the space on the side of the effluent weir 251 facing the primary sedimentation tank 1 and the high-density sedimentation tank 2. The effluent weir 251 of the primary sedimentation tank 1 and the high-density sedimentation tank 2 equipped with sludge scrapers 25 is an existing structure. This application is only a further description for the purpose of understanding. The primary sedimentation tank 1 is provided with an inlet pipe 12 on one side, and the high-density sedimentation tank 2 is provided with a drain pipe 26 at the upper end that is distributed corresponding to the effluent weir 251.
[0026] like Figure 1 and Figure 2 The primary sedimentation tank 1 and the high-density sedimentation tank 2 are supported by several columns 14 at the bottom, so that the primary sedimentation tank 1 and the high-density sedimentation tank 2 are far away from the ground, and the bottom of the primary sedimentation tank 1 and the high-density sedimentation tank 2 are provided with sludge discharge holes 15.
[0027] like Figure 1 and Figure 2 The two ends of the coagulation tank 21, flocculation tank 22 and pH adjustment tank 23 are fixed to the outer walls of the primary sedimentation tank 1 and the high-density sedimentation tank 2, respectively, so that the coagulation tank 21, flocculation tank 22 and pH adjustment tank 23 can be fixed, and the bottom of the coagulation tank 21, flocculation tank 22 and pH adjustment tank 23 is far away from the ground.
[0028] like Figure 1 and Figure 2The inlet pipe 12 directs the desulfurization wastewater to the primary sedimentation tank 1. TMT-15 reagent is added to the primary sedimentation tank 1 to remove heavy metals such as lead, copper, and mercury. The settled sludge is discharged from the sludge discharge hole 15 at the bottom of the primary sedimentation tank 1 into the sludge tank. The clearer water is collected from the upper effluent weir plate 251 of the primary sedimentation tank and enters the coagulation tank 21 through the primary effluent pipe 11. The coagulant added to the coagulation tank 21 is generally PAC or polyferric sulfate, whose main function is to destabilize suspended particles, i.e., to destabilize them. Subsequently, the wastewater is directed to the pH adjustment tank 23 through a connecting component. Sodium hydroxide solution is added to the pH adjustment tank 23, firstly to increase the pH value of the wastewater, and secondly... Secondly, it can remove some temporary hardness in the water, and then pass it into the flocculation tank 22. PAM flocculant is added to the flocculation tank 22, and then suspended particles are generated. Under the adsorption bridging effect of PAM, they aggregate to form large flocs that are easy to settle. The large flocs slowly enter the high-density sedimentation tank 2 with the water flow, which can avoid damage to the flocs. The large flocs settle in the high-density sedimentation tank 2, and finally are discharged into the sludge tank through the sludge discharge hole 15 at the bottom of the high-density sedimentation tank 2. The clear liquid on the upper layer of the high-density sedimentation tank 2 is collected through the effluent weir plate 251 and discharged through the drain pipe 26. In this way, the purpose of reducing heavy metals and reducing turbidity in desulfurization wastewater is achieved.
[0029] like Figure 1 and Figure 2 Each of the coagulation tank 21, flocculation tank 22 and pH adjustment tank 23 is equipped with a vent pipe 211 at the bottom, and each vent pipe 211 is equipped with a shut-off valve to facilitate the discharge of impurities and sludge accumulated at the bottom of the coagulation tank 21, flocculation tank 22 and pH adjustment tank 23.
[0030] like Figure 1 and Figure 2 and Figure 3 The upper walls of the coagulation tank 21, flocculation tank 22, and pH adjustment tank 23 are all equipped with crossbeams 27. Each crossbeam 27 is equipped with a stirring shaft 271 for stirring in the coagulation tank 21, flocculation tank 22, and pH adjustment tank 23. Each stirring shaft 271 has several stirring blades 272 on its outer wall. The crossbeam 27 is equipped with a motor to drive each stirring shaft 271 to rotate. In addition, the flocculation tank 22 is equipped with a guide tube 28 on its wall through horizontally distributed connecting rods. The guide tube 28 is open at the top and bottom. The stirring shafts 271 and stirring blades 272 of the flocculation tank 22 are all inserted into the guide tube 28. The return pipe 24 is set on the lower wall of the flocculation tank 22, with one end connected to the pH adjustment tank 23 and the other end bent upwards into the guide tube 28.
[0031] like Figure 1 and Figure 2 and Figure 3 The stirring shaft 271 and stirring blade 272 are located inside the guide tube 28. Under the action of the stirring blade 272, the wastewater and the agent in the guide tube 28 are mixed evenly. At this time, the agent is also introduced into the guide tube 28.
[0032] like Figure 1 and Figure 2 A guide pipe 13 extending downwards into the coagulation tank 21 is connected to the initial outlet pipe 11 via a flange. The guide pipe 13 is located on one side of the stirring shaft 271 inside the coagulation tank 21. The guide pipe 13 facilitates the entry of wastewater into the coagulation tank 21 for reaction and sedimentation. As the wastewater flows from the bottom of the coagulation tank 21 to the upper layer, it reacts with the reagents. The upper layer liquid of the coagulation tank 21 flows into the pH adjustment tank 23 through a connecting piece.
[0033] like Figure 1 and Figure 2 The connecting component includes a connecting pipe 293 disposed between the coagulation tank 21 and the pH adjustment tank 23. Both ends of the connecting pipe 293 are connected to the upper walls of the coagulation tank 21 and the pH adjustment tank 23, respectively, and it spans across the flocculation tank 22, facilitating liquid flow from the coagulation tank 21 to the pH adjustment tank 23. The liquid level in the coagulation tank 21 is higher than that in the pH adjustment tank 23, and the liquid level in the pH adjustment tank 23 is higher than that in the flocculation tank 22.
[0034] like Figure 1 and Figure 2 The high-density sedimentation tank 2 has buffer plates 29 distributed towards the gap 221 on its walls. The buffer plates 29 are positioned opposite the walls of the high-density sedimentation tank 2, and the lower end of each buffer plate 29 has an inclined plate 291 that gradually slopes away from the gap 221. A vertical plate 292 is located at the lower end of the inclined plate 291. Both ends of the inclined plate 291 and the vertical plate 292 are connected to the walls of the high-density sedimentation tank 2, with the lower end of the vertical plate 292 positioned above the scraper blade of the sludge scraper 25. The buffer plates 29, inclined plates 291, and vertical plates 292 are all designed to block the wastewater flowing out of the gap 221, changing its flow direction and causing it to flow towards the scraper blade of the sludge scraper 25, thus accelerating sedimentation.
[0035] like Figure 1 and Figure 2 Both the primary sedimentation tank 1 and the high-density sedimentation tank 2 are equipped with inspection manhole pipes 294 on opposite sides. These manhole pipes 294 are sealed by a sealing plate (not shown in the diagram), which is detachably connected to the manhole pipe 294 wall using bolts. The diameter of the manhole pipe 294 facilitates inspection of the bottom of the primary sedimentation tank 1 and the high-density sedimentation tank 2 by maintenance personnel.
[0036] In addition, the dosing device for each tank includes a dissolving tank containing the required chemical, a metering pump, and a dosing pipe entering each tank. The metering pump extracts the chemical from the dissolving tank as needed and adds it to the required tank through the dosing pipe. The dosing device is generally existing technology; this application is merely a further description for illustrative purposes.
[0037] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.
Claims
1. A wastewater sedimentation tank for effectively treating desulfurization wastewater, characterized in that, It includes a primary sedimentation tank (1) and a high-density sedimentation tank (2) set on the ground, and a coagulation tank (21), a flocculation tank (22) and a pH adjustment tank (23) arranged in a straight line between the primary sedimentation tank (1) and the high-density sedimentation tank (2). The primary sedimentation tank (1) has an initial effluent pipe (11) connected to the coagulation tank (21). The coagulation tank (21) is connected to the pH adjustment tank (23) through a connecting piece. The pH adjustment tank (23) is connected to the flocculation tank (22) through a return pipe (24). The flocculation tank (22) has a notch (221) on the upper wall of the tank that connects to the high-density sedimentation tank (2). Both the primary sedimentation tank (1) and the high-density sedimentation tank (2) are equipped with sludge scrapers (25) and effluent weirs (251) are provided on the upper end of the inner side wall. The primary sedimentation tank (1) is equipped with an inlet pipe (12) on one side, and the high-density sedimentation tank (2) is equipped with a drain pipe (26) corresponding to the effluent weir (251) at the upper end.
2. The wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The upper walls of the coagulation tank (21), flocculation tank (22) and pH adjustment tank (23) are all provided with crossbeams (27), and the crossbeams (27) are respectively provided with stirring shafts (271) for stirring in the coagulation tank (21), flocculation tank (22) and pH adjustment tank (23). Each stirring shaft (271) has several stirring blades (272) on its outer wall.
3. The wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 2, characterized in that, The flocculation tank (22) has a guide tube (28) on its wall through horizontally distributed connecting rods. The guide tube (28) is open at the top and bottom. The stirring shaft (271) and stirring blades (272) of the flocculation tank (22) are both installed inside the guide tube (28). The return pipe (24) is installed on the lower wall of the flocculation tank (22) and one end is connected to the pH adjustment tank (23). The other end bends upward and enters the guide tube (28).
4. A wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The initial outlet pipe (11) is connected by a flange to a guide pipe (13) extending downward into the coagulation tank (21), and the guide pipe (13) is located on one side of the stirring shaft (271) in the coagulation tank (21).
5. A wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The high-density sedimentation tank (2) has buffer plates (29) distributed towards the gap (221) on its tank wall. The buffer plates (29) are set on the opposite tank wall of the high-density sedimentation tank (2). The lower end of the buffer plates (29) is provided with an inclined plate (291) that gradually tilts away from the gap (221). The lower end of the inclined plate (291) is provided with a vertical plate (292). Both ends of the inclined plate (291) and the vertical plate (292) are connected to the tank wall of the high-density sedimentation tank (2). The lower end of the vertical plate (292) is located above the scraper of the sludge scraper (25).
6. A wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The connecting component includes a connecting pipe (293) disposed between the coagulation tank (21) and the pH adjustment tank (23). The two ends of the connecting pipe (293) are respectively connected to the upper walls of the coagulation tank (21) and the pH adjustment tank (23), and span across the flocculation tank (22).
7. A wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The bottom of the primary sedimentation tank (1) and the high-density sedimentation tank (2) are supported by several columns (14), and the bottom of the primary sedimentation tank (1) and the high-density sedimentation tank (2) are provided with sludge discharge holes (15). The two ends of the coagulation tank (21), the flocculation tank (22) and the pH adjustment tank (23) are respectively fixed on the outer walls of the primary sedimentation tank (1) and the high-density sedimentation tank (2). The bottom of the coagulation tank (21), the flocculation tank (22) and the pH adjustment tank (23) are provided with vent pipes (211), and each of the vent pipes (211) is provided with a shut-off valve.
8. A wastewater sedimentation tank for effectively treating desulfurization wastewater as described in claim 1, characterized in that, The primary sedimentation tank (1) and the high-density sedimentation tank (2) are each provided with a maintenance manhole pipe (294) on the opposite side. The maintenance manhole pipe (294) is closed by a sealing plate, which is detachably connected to the wall of the maintenance manhole pipe (294) by bolts.