A high-density settling device with delayed fouling

Abstract

This application relates to the field of wastewater treatment equipment, and in particular to a high-density sedimentation device for delaying scaling. It includes a pretreatment tank, a flocculation tank, a sedimentation tank, and a sludge discharge pipe. The pretreatment tank is covered with a first cover plate, and a partition plate is fixed to its inner bottom. The partition plate divides the pretreatment tank into a coagulation chamber and a reaction chamber. An inlet baffle and a jet assembly are installed inside the pretreatment tank, with the jet assembly located on the side of the inlet baffle facing the flocculation tank. A second cover plate is installed on the top of the flocculation tank, and a guide tube is installed inside the flocculation tank. A stirring assembly with its stirring end located inside the upper opening of the guide tube is installed on the second cover plate. A third cover plate is installed on the top of the sedimentation tank, and a sludge scraper is installed on the third cover plate. An inclined tube and a water collection trough embedded in the inclined tube are installed inside the sedimentation tank. The bottom of the water collection trough is connected to the upper end of the inclined tube, achieving the effect of delaying the scaling rate of the high-density sedimentation tank and increasing sedimentation efficiency.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment equipment, and in particular to a high-density sedimentation device for delaying scaling. Background Technology

[0002] Currently, in industrial wastewater treatment processes in the petroleum or chemical industries, wastewater contains high concentrations of hardness ions and silicon. If these ions are not removed, they will affect the effectiveness of subsequent treatment processes, such as clogging of reverse osmosis membranes. Conventional high-density sedimentation tanks use a double-alkali method by adding agents such as lime or soda ash to react the hardness ions with relevant silicon removal agents to form precipitates, thereby removing hardness and silicon from the wastewater.

[0003] Existing high-density sedimentation tanks for hardening and silica removal, while effectively removing calcium and magnesium ions from high-hardness wastewater to reduce water hardness, are prone to scaling during operation. During the hardening process, chemicals such as lime (Ca(OH)2), soda ash (Na2CO3), or magnesium hydroxide are added to the wastewater. These chemicals react with the calcium and magnesium ions in the water, forming precipitates such as calcium carbonate (CaCO3), magnesium hydroxide (Mg(OH)2), or magnesium silicate (MgSiO3). The water flow conditions within these high-density sedimentation tanks also affect scaling; if the water flow is too slow, precipitates tend to accumulate within the tank.

[0004] Scale buildup reduces the effective volume of sedimentation tanks, lowers sedimentation efficiency, and affects wastewater treatment. For example, scale buildup on inclined tubes reduces the cross-sectional area for water flow, increasing water velocity and thus hindering sediment settling. Scale buildup also increases the operating load on equipment, leading to malfunctions. For instance, scale buildup on agitator blades can cause imbalance, increasing the motor load and potentially causing it to burn out. Furthermore, scale requires regular cleaning and maintenance, increasing the operating and maintenance costs and workload of high-density sedimentation tanks.

[0005] The existing technical solutions mentioned above have the following defects: sediments are deposited in the pipes, tank walls, agitator blades and inclined tubes of the high-density sedimentation tank, forming a scale layer. When water quality changes, the sedimentation reaction is incomplete or the properties of the sediments change, scale is easily formed in the high-density sedimentation tank. At the same time, it leads to mismatch in the dosage of chemicals and excessive turbidity in the effluent. Utility Model Content

[0006] This application provides a high-density sedimentation device for slowing down scaling in order to reduce the scaling rate of high-density sedimentation tanks and increase sedimentation efficiency.

[0007] The above-mentioned technical objective of this application is achieved through the following technical solution: A high-density sedimentation device for delaying scaling includes a pretreatment tank, a flocculation tank connected to the pretreatment tank, a sedimentation tank connected to the side of the flocculation tank away from the pretreatment tank, and a sludge discharge pipe with one end connected to the bottom of the sedimentation tank and a section away from the sedimentation tank connected to the pretreatment tank and the flocculation tank respectively. The top of the pretreatment tank is covered with a first cover plate. A partition plate is fixed to the bottom of the pretreatment tank and is spaced apart from the first cover plate. The partition plate divides the pretreatment tank into a coagulation chamber and a reaction chamber. The reaction chamber is located between the coagulation chamber and the flocculation tank and is connected to the flocculation tank. Both the coagulation chamber and the reaction chamber are equipped with inlet baffles and jet components. The inlet baffle in the coagulation chamber is close to the inlet side of the pretreatment tank, and the inlet baffle in the reaction chamber is close to the partition plate and is spaced apart from the partition plate. The jet components are located on the side of the inlet baffle facing the flocculation tank. A second cover plate is provided on the top of the flocculation tank, and a guide tube is installed inside the flocculation tank. A stirring assembly with its stirring end located inside the upper opening of the guide tube is installed on the second cover plate. The sedimentation tank is equipped with a third cover plate at the top, and a sludge scraper is installed on the third cover plate. The sedimentation tank is equipped with an inclined tube and a water collection trough embedded in the inclined tube. The bottom of the water collection trough is connected to the upper end of the inclined tube.

[0008] By adopting the above technical solution, wastewater enters the coagulation and reaction chambers under the guidance of the inlet baffle. The baffle's obstruction allows for more uniform mixing and reaction. Sludge containing sediment tends to accumulate in the dead corners at the bottom of the pretreatment tank over time; this can be addressed periodically by increasing the operating frequency of the bottom ejector and removing the sludge. The high-speed fluid ejected from the nozzles of the ejector carries the coagulant, achieving efficient mixing. Adding chemicals such as lime or soda ash to the pretreatment tank reacts with calcium and magnesium ions in the water, producing precipitates such as calcium carbonate and magnesium hydroxide. Most of these precipitates adhere to the coagulant's coagulation nuclei, reducing adhesion to the equipment and slowing down scaling.

[0009] Optionally, the jet assembly includes a first mounting tube fixed at its upper end to the bottom of the first cover plate and a plurality of jets fixed at intervals on the first mounting tube.

[0010] Optionally, the pretreatment tank is also provided with a dosing pipe, and the dosing pipe has multiple sets of dosing holes that correspond one-to-one with the multiple jet injectors.

[0011] By adopting the above technical solution, after lime, magnesium agent, sodium carbonate and sodium hydroxide are added to the coagulation chamber through the dosing pipe, the jet nozzle sprays out wastewater and stirs the wastewater through fluid dynamics to form a circulation, so that the reagents and wastewater are mixed quickly and efficiently.

[0012] Optionally, the guide tube includes a cylinder, a flared section fixed to the lower end of the cylinder, and a support plate with its upper end fixed to the flared section and its lower end fixed to the bottom of the flocculation tank, wherein the lower end of the flared section is spaced apart from the bottom of the flocculation tank.

[0013] By adopting the above technical solution, the wastewater enters the inside of the guide tube and forms an internal circulation. Through the addition of flocculant polyacrylamide solution, the wastewater in the guide tube can be fully mixed with the flocculant in two directions, from top to bottom and from bottom to top, under the action of the agitator. After being slowly stirred by the agitator, the complex compounds and complex flocs formed rapidly aggregate and grow larger.

[0014] Optionally, a first online pH meter is suspended and installed at the bottom of the second cover plate, located inside the flocculation tank. The first online pH meter is located on the side of the cylinder away from the pretreatment tank.

[0015] By adopting the above technical solution, the pH value of the wastewater entering the flocculation tank can be monitored in real time. If the pH value of the wastewater is not around 10.3 or 11, or if the pH value is too high or too low, the amount of reagent added in the pretreatment tank and the flocculation tank can be manually adjusted according to the real-time pH value.

[0016] Optionally, a first aeration device is inclinedly installed at the bottom of the flocculation tank and below the first online pH meter.

[0017] By adopting the above technical solution, the first aeration device can reduce the accumulation of sludge at the bottom of the plug flow zone and slow down scaling.

[0018] Optionally, the sedimentation tank is equipped with a second aeration device located below the inclined tube.

[0019] By adopting the above technical solution, when sludge accumulates above the inclined tube due to abnormal operation, the aeration device can be turned on for quick cleaning. At the same time, the aeration device below the inclined tube operates indirectly, which also reduces scaling on the inclined tube and the effluent tank.

[0020] Optionally, an outlet pipe is installed on the outer wall of the sedimentation tank away from the flocculation tank, and a second online pH meter is installed inside the outlet pipe.

[0021] By adopting the above technical solution, it is convenient to discharge the clear water in the sedimentation tank while also being able to monitor the pH of the clear water.

[0022] Optionally, the sedimentation tank is connected to a sludge return pipe, one end of which is connected to the bottom of the sedimentation tank, and the other end passes through the second cover plate and is located in the flocculation tank.

[0023] By adopting the above technical solution, the sludge deposited in the sedimentation tank can be transported back to the flocculation zone by a sludge pump. The sludge return flow rate can be adjusted according to the on-site operating conditions. Under the condition that the polymer and sewage have been fully mixed, the injection of return sludge greatly enhances the flocculation effect.

[0024] Optionally, the first cover plate is provided with a locking assembly, which includes a shell fixed to the first cover plate and having an open end and a closed end respectively, a sealing plate fixed to the open end of the shell, a locking rod movably passing through the closed end of the shell and the sealing plate and having a length greater than the sum of the lengths of the shell and the sealing plate, a sliding baffle slidably disposed inside the shell and fixedly connected to the locking rod, and a spring sleeved on the locking rod and having its two ends abutting against the sliding baffle and the sealing plate respectively. The section of the locking rod located outside the closed end of the shell is spaced apart from the surface of the first cover plate. The first cover plate has a strip hole for inserting a water inlet baffle. A horizontal plate with a width greater than the strip hole is fixed to the top of the water inlet baffle. The horizontal plate can be located between the locking rod and the first cover plate, and the outer wall of the locking rod is in contact with the upper surface of the horizontal plate.

[0025] By adopting the above technical solution, the locking rod can lock the horizontal plate on the first cover plate, so that even after the sewage enters the pretreatment tank and causes a strong impact on the inlet baffle, the inlet baffle will not easily shake. When the inlet baffle needs to be cleaned regularly, pulling the end of the locking rod away from the sliding baffle can disengage the locking rod from the horizontal plate, making it easy to remove the inlet baffle from the first cover plate for cleaning.

[0026] In summary, this application has the following technical effects: 1. By setting up a pretreatment tank, flocculation tank, sedimentation tank, and sludge discharge pipe, wastewater enters the coagulation chamber and reaction chamber under the guidance of the inlet baffle. The baffle's obstruction allows for more uniform mixing and reaction. Sludge containing sediment tends to accumulate in the dead corners at the bottom of the pretreatment tank over time; this can be addressed periodically by increasing the operating frequency of the bottom ejector and removing the sludge. The high-speed fluid ejected from the nozzles of the ejector carries the coagulant, achieving efficient mixing. Adding lime, magnesium oxide, or soda ash to the pretreatment tank reacts with calcium and magnesium ions in the water, generating precipitates such as calcium carbonate, magnesium hydroxide, and magnesium silicate. Most of these precipitates adhere to the coagulant's flocculation nuclei, reducing adhesion to the equipment and slowing down scaling. 2. By setting up a jet assembly, the jet nozzle sprays wastewater and uses hydrodynamics to stir the wastewater, forming a circulation, which enables the reagents and wastewater to mix quickly and efficiently; the agitator device used in conventional high-density sedimentation tanks is eliminated; 3. By setting up a guide tube, the wastewater enters the guide tube and forms an internal circulation. Through the flocculant addition ring, the flocculant polyacrylamide solution is added. Under the action of the agitator, the wastewater in the guide tube can be fully mixed with the flocculant in two directions: from top to bottom and from bottom to top. After being slowly stirred by the agitator, the complex compounds and complex flocs formed rapidly aggregate and grow larger. Attached Figure Description

[0027] Figure 1 This is a cross-sectional structural diagram of this application; Figure 2 This is a cross-sectional view of the pretreatment tank; Figure 3 It is a cross-sectional structural diagram of the first cover plate, locking assembly and water inlet baffle; Figure 4 This is a cross-sectional structural diagram of a flocculation tank.

[0028] Explanation of reference numerals in the attached drawings: 1. Pretreatment tank; 11. First cover plate; 111. Locking assembly; 1111. Outer shell; 1112. Sliding baffle; 1113. Locking rod; 1114. Spring; 1115. Sealing plate; 12. Divider plate; 13. Coagulation chamber; 14. Reaction chamber; 15. Sludge discharge pipe in the coagulation zone; 16. Sludge discharge pipe in the reaction zone; 17. Inlet baffle; 171. Horizontal plate; 172. Handle; 18. Dosing pipe; 19. Jet assembly; 191. First mounting pipe; 192. Jet ejector; 2. Connecting pipe; 3. Flocculation tank; 31. Second cover plate; 32. 321. Guide tube; 322. Cylinder body; 323. Flared section; 324. Support plate; 35. Agitator; 36. Agitator motor; 37. Agitator shaft; 38. Agitator blades; 39. Flocculant addition ring; 30. First online pH meter; 31. Second installation pipe; 32. First aeration device; 43. Sludge discharge pipe in flocculation zone; 44. Sedimentation tank; 45. Third cover plate; 46. Sludge scraper; 47. Second aeration device; 48. Inclined tube; 49. Water collection tank; 40. Water outlet pipe; 41. Second online pH meter; 42. Sludge return pipe; 5. Sludge discharge pipe. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] This application discloses a high-density sedimentation device for delaying scaling, referring to... Figure 1 The sedimentation device includes a pretreatment tank 1, a connecting pipe 2 that is inclined and fixed at its upper end to the outer wall of the pretreatment tank 1, a flocculation tank 3 whose outer wall is fixed to the lower end of the connecting pipe 2, a sedimentation tank 4 that is connected to the side of the flocculation tank 3 away from the connecting pipe 2, and a sludge discharge pipe 5 that is fixed at one end to the bottom of the sedimentation tank 4 and is connected to the bottom of the pretreatment tank 1 and the bottom of the flocculation tank 3 respectively.

[0031] Reference Figure 2 The pretreatment tank 1 is square in shape, with rounded corners to avoid dead angles and facilitate cleaning of sediment inside. The top of the pretreatment tank 1 is open, covered by a first cover plate 11. A partition plate 12 is vertically fixed to the bottom of the pretreatment tank 1, with its top spaced apart from the first cover plate 11. The partition plate 12 divides the interior of the pretreatment tank 1 into a coagulation chamber 13 and a reaction chamber 14, with the connecting pipe 2 communicating with the upper part of the reaction chamber 14.

[0032] Reference Figure 2 A sludge discharge pipe 15 for the coagulation zone and a sludge discharge pipe 16 for the reaction zone are fixedly installed on the outer bottom of the pretreatment tank 1. One end of the sludge discharge pipe 15 for the coagulation zone is connected to the interior of the coagulation zone, and the other end is fixedly connected to and connected to the sludge discharge pipe 5. One end of the sludge discharge pipe 16 for the reaction zone is connected to the interior of the reaction zone, and the other end is fixedly connected to and connected to the sludge discharge pipe 5.

[0033] Reference Figure 2 An inlet baffle 17, a dosing pipe 18, and a jet assembly 19 are respectively installed in the coagulation chamber 13 and the reaction chamber 14. The inlet baffle 17 is inserted into the first cover plate 11, the dosing pipe 18 is vertically inserted through the first cover plate 11 and spaced apart from the inlet baffle 17, and the jet assembly 19 is fixed to the lower surface of the first cover plate 11 and located between the inlet baffle 17 and the dosing pipe 18. The inlet baffle 17 in the coagulation chamber 13 is located on the side of the coagulation chamber 13 away from the partition plate 12, and the upper part of the side wall of the coagulation chamber 13 near the inlet baffle 17 is connected to an external sewage source. The dosing pipe 18 in the coagulation chamber 13 is located between the jet assembly 19 and the partition plate 12. The inlet baffle 17 in the reaction chamber 14 is located on the side near the partition plate 12 and spaced apart from the partition plate 12, so that the partition plate 12 and the inlet baffle 17 in the reaction chamber 14 form an inlet passage for the reaction chamber 14.

[0034] Combination Figure 2 and Figure 3 The first cover plate 11 has a strip-shaped hole for inserting a water inlet baffle 17 into the pretreatment tank 1. The water inlet baffle 17 is adapted to the strip-shaped hole and inserted into it. A strip-shaped horizontal plate 171 is fixedly connected to the upper surface of the water inlet baffle 17. A handle 172 is fixedly connected to the upper surface of the horizontal plate 171. The handle 172 and the water inlet baffle 17 are respectively located on the two surfaces of the horizontal plate 171. The width of the horizontal plate 171 is greater than the width of the strip-shaped hole. After the horizontal plate 171 abuts against the first cover plate 11, the bottom of the water inlet baffle 17 is suspended above the bottom of the pretreatment tank 1.

[0035] Reference Figure 3A locking assembly 111 is fixedly disposed on the surface of the first cover plate 11. The locking assembly 111 includes a housing 1111 fixed to the first cover plate 11 with an open end and a closed end, respectively; a sliding baffle 1112 movably disposed within the housing 1111; a locking rod 1113 passing through the middle of the sliding baffle 1112 and slidably passing through the closed end of the housing 1111 at one end; a spring 1114 sleeved on the locking rod 1113 and located on a section of the locking rod 1113 near the open end of the housing 1111; and a spring fixedly disposed on the open end of the housing 1111. The locking rod 1113 slides through the sealing plate 1115. The locking rod 1113 is fixedly connected to the sliding baffle 1112. The length of the locking rod 1113 is greater than the sum of the lengths of the outer shell 1111 and the sealing plate 1115. The length of the section of the locking rod 1113 outside the sealing plate 1115 is greater than the length of the section of the locking rod 1113 outside the closed end of the outer shell 1111. The locking rod 1113 is spaced apart from the upper surface of the first cover plate 11. The horizontal plate 171 can be located between the locking rod 1113 and the first cover plate 11, and the outer wall of the locking rod 1113 is in contact with the upper surface of the horizontal plate 171. The spring 1114 is arranged in an extended state inside the outer shell 1111, and its two ends abut against the two opposite surfaces of the sliding baffle 1112 and the sealing plate 1115, respectively.

[0036] The locking rod 1113 is a strip rod with a rectangular end face. The section of the locking rod 1113 located outside the closed end of the housing 1111 has an upward inclined surface facing the handle 172. When the water inlet baffle 17 is inserted into the strip hole, the horizontal plate 171 abuts against the inclined surface, which allows the locking rod 1113 to automatically retract into the housing 1111, thereby facilitating the locking of the water inlet baffle 17.

[0037] Reference Figure 2 A dosing pipe 18, passing through the upper surface of the first cover plate 11, is connected to a dosing device at one end. Multiple sets of outlet holes are evenly spaced along a section of the dosing pipe 18 within the pretreatment tank 1. The jet assembly 19 includes a vertically mounted first mounting pipe 191, its upper end fixed to the lower surface of the first cover plate 11, and jet injectors 192 evenly spaced along the length of the first mounting pipe 191. Wires are connected to the jet injectors 192, passing through the first mounting pipe 191 and connected to an external power source. Multiple jet injectors 192 are arranged corresponding to multiple sets of outlet holes. After lime, magnesium oxide, sodium carbonate, and sodium hydroxide are added to the coagulation chamber 13 through the dosing pipe 18, the jet injectors 192 spray wastewater, which is then agitated by hydrodynamic forces to form a circulating flow, allowing the chemicals and wastewater to mix rapidly and efficiently. Chemical agents such as lime, magnesium hydroxide, or sodium carbonate react with calcium and magnesium ions in water to produce precipitates such as calcium carbonate, magnesium hydroxide, and magnesium silicate. Most of these precipitates adhere to the coagulation nuclei of the coagulant, reducing adhesion to the equipment and slowing down scaling.

[0038] The upper end of the connecting pipe 2 is located near the upper part of the pretreatment tank 1. Flanges are fixed to the outer walls of both the pretreatment tank 1 and the flocculation tank 3. Flanges are also provided at both ends of the connecting pipe 2. The connecting pipe 2 is connected between the pretreatment tank 1 and the flocculation tank 3 through the flanges, which facilitates the disassembly and cleaning of the connecting pipe 2 after long-term use.

[0039] Reference Figure 4 The flocculation tank 3 is square in shape, with rounded corners to avoid dead angles and facilitate cleaning of sediment from the pretreatment tank 1. The top of the flocculation tank 3 is open, covered by a second cover plate 31. A guide tube 32 is vertically fixed inside the flocculation tank 3, with its lower end fixed to the bottom. The guide tube 32 includes a vertically positioned cylinder 321 with openings at both ends, a flared section 322 fixed to the lower end of the cylinder 321, and multiple support plates 323 spaced at equal angles around the flared section 322. The smaller opening end of the flared section 322 connects to the lower end of the cylinder 321. The outer wall of the cylinder 321 is spaced apart from the inner wall of the flocculation tank 3. The lower ends of the support plates 323 are fixed to the bottom of the flocculation tank 3, and the lower end of the cylinder 321 is suspended above the bottom of the flocculation tank 3.

[0040] A stirrer 33 is provided on the second cover plate 31. The stirrer 33 includes a stirring motor 331 fixedly mounted on the upper surface of the second cover plate 31 with its shaft vertically mounted, a stirring shaft 332 vertically mounted and whose upper end is fixedly connected to the shaft of the stirring motor 331, and stirring blades 333 installed at the lower end of the stirring shaft 332 and located in the upper opening of the cylinder 321. A flocculant adding ring 34 in the shape of a ring and located below the stirring blades 333 is also provided inside the guide cylinder 32. The flocculant adding ring 34 is made of tubular material and has several dosing holes on its outer wall. The flocculant adding ring 34 is connected to an external dosing device.

[0041] A second mounting pipe 351 is vertically fixed to the lower surface of the second cover plate 31. The second mounting pipe 351 is located on the side of the guide tube 32 away from the connecting pipe 2. A first online pH meter 35 is installed at the lower end of the second mounting pipe 351. The first online pH meter 35 can be connected to an external terminal of the sedimentation device via wired or wireless connection to monitor the pH value of the wastewater entering the flocculation tank 3 in real time. If the pH of the wastewater is not around 10.3 or 11, or if the pH is too high or too low, the amount of reagent added in the pretreatment tank 1 and the flocculation tank 3 is manually adjusted according to the real-time pH value. The bottom of the flocculation tank 3 on the side away from the connecting pipe 2 is connected to the sedimentation tank 4. A first aeration device 36 is installed at the bottom of the flocculation tank 3, tilted towards the guide tube 32, which reduces the accumulation of sludge at the bottom of the plug flow zone and slows down scaling. A sludge discharge pipe 37 for the flocculation zone is fixedly connected to the bottom of the flocculation tank 3. One end of the sludge discharge pipe 37 is fixedly connected to and connected to the flocculation tank 3, and the other end of the sludge discharge pipe 37 is fixedly connected to and connected to the sludge discharge pipe 5.

[0042] Wastewater enters the flocculation tank 3 through the reaction chamber 14 via the connecting pipe 2 and then enters the guide tube 32, forming an internal circulation inside the guide tube 32. Flocculant polyacrylamide solution is added through the flocculant dosing ring. Under the action of the agitator 33, the wastewater in the guide tube 32 can be fully mixed with the wastewater in two directions, from top to bottom and from bottom to top. After being slowly stirred by the agitator 33 for 10-15 minutes, the complex compounds and complex flocs formed rapidly aggregate and grow larger.

[0043] Reference Figure 1 One side of the sedimentation tank 4 is connected to the flocculation tank 3. The top of the sedimentation tank 4 is open and its interior is circular. A third cover plate 41 is installed at the open. A sludge scraper 42 is installed on the third cover plate 41 at the center of the sedimentation tank 4. A second aeration device 43 is installed in the sedimentation tank 4, near the open section. Several inclined tubes 44 in a honeycomb shape are installed on the upper part of the second aeration device 43. Multiple receiving tanks are formed at intervals at the upper end of the inclined tubes 44. A water collection tank 45 is set in the receiving tank. The bottom of the water collection tank 45 is connected to the upper end of the inclined tubes 44, allowing a stream of clean water to enter the water collection tank 45.

[0044] An outlet pipe 46 is installed on the outer wall of the sedimentation tank 4 on the side opposite to the flocculation tank 3. A second online pH meter 47 is installed inside the outlet pipe 46. A sludge return pipe 48 is installed on the bottom of the sedimentation tank 4. One end of the sludge return pipe 48 is fixedly connected to and communicates with the sedimentation tank 4, and the other end passes through the second cover plate 31 and is located inside the flocculation tank 3. A sludge pump is installed on the sludge return pipe 48, which can transport the sludge deposited in the sedimentation tank 4 back to the flocculation zone. The sludge return flow rate can be adjusted according to the on-site operating conditions. Under the condition that the polymer and sewage are fully mixed, the injection of return sludge greatly enhances the flocculation effect, producing large and uniform flocs that can settle quickly. By adjusting the frequency of the sludge circulation pump, the sludge circulation volume can be varied to cope with changes in the influent flow rate and load.

[0045] Sludge pumps are installed on the sludge discharge pipe 15 in the coagulation zone, the sludge discharge pipe 16 in the reaction zone, the sludge discharge pipe 37 in the flocculation zone, and the sludge discharge pipe 5. These pumps are used to periodically pump out and clean the sludge in the sedimentation device, thereby reducing the scaling problem caused by sludge accumulation and also reducing the workload of maintenance personnel to clean the bottom of the pool.

[0046] The inner surfaces of the pretreatment tank 1, flocculation tank 3 and sedimentation tank 4 are coated with a hydrophobic layer. The hydrophobic layer is made of a coating material with added polytetrafluoroethylene. The polytetrafluoroethylene coating is hydrophobic and has low surface energy, which can effectively inhibit the formation of scale nuclei on its surface.

[0047] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A scale delay high density settling device, characterized by: It includes a pretreatment tank (1), a flocculation tank (3) connected to the pretreatment tank (1), a sedimentation tank (4) connected to the side of the flocculation tank (3) away from the pretreatment tank (1), and a sludge discharge pipe (5) with one end connected to the bottom of the sedimentation tank (4) and a section away from the sedimentation tank (4) connected to the pretreatment tank (1) and the flocculation tank (3) respectively. The pretreatment tank (1) is covered with a first cover plate (11). A partition plate (12) is fixed to the bottom of the pretreatment tank (1) and the partition plate (12) is spaced apart from the first cover plate (11). The partition plate (12) divides the pretreatment tank (1) into a coagulation chamber (13) and a reaction chamber (14). The reaction chamber (14) is located between the coagulation chamber (13) and the flocculation tank (3) and is connected to the flocculation tank (3). Both the coagulation chamber (13) and the reaction chamber (14) are equipped with inlet baffles (17) and jet components (19). The inlet baffle (17) in the coagulation chamber (13) is close to the inlet side of the pretreatment tank (1), and the inlet baffle (17) in the reaction chamber (14) is close to the partition plate (12) and is arranged at intervals from the partition plate (12). The jet components (19) are respectively located on the side of the inlet baffle (17) facing the flocculation tank (3). The top of the flocculation tank (3) is provided with a second cover plate (31), and a guide tube (32) is installed inside the flocculation tank (3). A stirring assembly with the stirring end located inside the upper opening of the guide tube (32) is installed on the second cover plate (31). The sedimentation tank (4) is provided with a third cover plate (41) on top, and a sludge scraper (42) is installed on the third cover plate (41). The sedimentation tank (4) is provided with an inclined tube (44) and a water collection trough (45) embedded in the inclined tube (44). The bottom of the water collection trough (45) is connected to the upper end of the inclined tube (44).

2. The high-density sedimentation device for delaying scaling according to claim 1, characterized in that: The jet assembly (19) includes a first mounting tube (191) fixed at its upper end to the bottom of the first cover plate (11) and a plurality of jets (192) fixed at intervals to the first mounting tube (191).

3. The high-density sedimentation device for delaying scaling according to claim 2, characterized in that: The pretreatment tank (1) is also equipped with a dosing pipe (18), and the dosing pipe (18) has multiple sets of dosing holes that correspond one-to-one with the multiple jets (192).

4. A device for retarding scale formation in a high density settling tank according to claim 1 or 3, wherein: The guide tube (32) includes a tube body (321), a flared section (322) fixed to the lower end of the tube body (321), and a support plate (323) with its upper end fixed to the flared section (322) and its lower end fixed to the bottom of the flocculation tank (3). The lower end of the flared section (322) is arranged at a distance from the bottom of the flocculation tank (3).

5. A scale delay high density precipitation device as claimed in claim 4, wherein: The bottom of the second cover plate (31) is suspended and installed with a first online pH meter (35) located in the flocculation tank (3). The first online pH meter (35) is located on the side of the cylinder (321) away from the pretreatment tank (1).

6. A scale delay high density precipitation device according to claim 5, wherein: The first aeration device (36) is inclinedly installed at the bottom of the flocculation tank (3) and below the first online pH meter (35).

7. The high-density sedimentation device for delaying scaling according to claim 1, characterized in that: The sedimentation tank (4) is equipped with a second aeration device (43) located below the inclined tube (44).

8. The high-density sedimentation device for delaying scaling according to claim 7, characterized in that: The sedimentation tank (4) has an outlet pipe (46) installed on the outer wall of the side opposite to the flocculation tank (3), and a second online pH meter (47) is installed in the outlet pipe (46).

9. A scale delay high density precipitation device according to claim 7 or 8, wherein: The sedimentation tank (4) is connected to a sludge return pipe (48). One end of the sludge return pipe (48) is connected to the bottom of the sedimentation tank (4), and the other end passes through the second cover plate (31) and is located in the flocculation tank (3).

10. A high-density sedimentation device for delaying scaling according to claim 1, characterized in that: A locking assembly (111) is provided on the first cover plate (11). The locking assembly (111) includes a housing (1111) fixed to the first cover plate (11) with an open end and a closed end respectively at its two ends, a sealing plate (1115) fixed to the open end of the housing (1111), and a movably inserted through the closed end of the housing (1111) and the sealing plate (1115) with a length greater than the length of the housing (1111) and the sealing plate (1115). The lock rod (1113) with a total degree, the sliding baffle (1112) which is slidably disposed in the outer shell (1111) and fixedly connected to the lock rod (1113), and the spring (1114) which is sleeved on the lock rod (1113) and whose two ends respectively abut against the sliding baffle (1112) and the sealing plate (1115), the section of the lock rod (1113) located outside the closed end of the outer shell (1111) is arranged at intervals with the upper surface of the first cover plate (11); The first cover plate (11) has a strip hole for inserting the water inlet baffle (17). The top of the water inlet baffle (17) is fixed with a horizontal plate (171) with a width greater than the strip hole. The horizontal plate (171) can be located between the locking rod (1113) and the first cover plate (11), and the outer wall of the locking rod (1113) is in contact with the upper surface of the horizontal plate (171).

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