Sludge settling tank and sludge-water separation method
By introducing a rotary drive and stirring rod into the settling tank, combined with an irregularly shaped surrounding cylinder structure, the problem of insufficient mixing of sludge and precipitant was solved, achieving rapid sludge settling and efficient sludge-water separation, thus improving sludge treatment efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FUQING WATER RESOURCES & HYDRO POWER CONSTR ENG CO
- Filing Date
- 2024-05-21
- Publication Date
- 2026-05-29
AI Technical Summary
In existing sedimentation tanks, the sludge and precipitant are not mixed sufficiently, resulting in a slow reaction rate and slow sludge settling, which affects sludge treatment efficiency.
A sludge settling tank was designed, which uses a rotary drive and stirring rod to quickly mix sludge and flocculant through a mixing tube, and uses an irregularly shaped surrounding cylinder structure to accelerate sludge settling. Combined with a drainage mechanism and baffles, it reduces water disturbance.
It achieves rapid and thorough mixing of sludge and precipitant, improves sludge settling speed and treatment efficiency, reduces disturbance to the sludge and water at the bottom of the tank, and enhances sludge-water separation effect.
Smart Images
Figure CN118324385B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of sludge treatment technology, and more specifically, to a sludge settling tank and a sludge-water separation method. Background Technology
[0002] When treating river silt, a cutter suction dredger is first used to extract the silt from the river. The silt is then piped into a sludge tank and pumped into a sedimentation tank. A flocculant is added to the sedimentation tank so that most of the suspended solids settle at the bottom of the tank. The supernatant overflows from the top of the sedimentation tank into a clear water tank for temporary storage. The sludge at the bottom of the sedimentation tank is then transported to a filter press for further dewatering.
[0003] The main function of the settling tank is to reduce the water content of the sludge by adding a settling agent, thereby reducing the operating load of the subsequent filter press and improving the sludge treatment efficiency.
[0004] Some sedimentation tanks operate by drawing sludge from the outside into the central pipe of the tank from top to bottom. The sludge diffuses and suspends within the tank, while a flocculant is added. The sludge and flocculant mix naturally within the tank. Under the influence of the flocculant and the sludge's own gravity, the suspended sludge gradually settles into the conical hopper at the bottom of the tank. The supernatant overflows from the top of the tank and is channeled into a storage tank through pipes or long troughs. The bottom sludge is periodically discharged from the sedimentation tank. Using this type of sedimentation tank to separate clean water and sludge results in a slow and inefficient mixing of the sludge and flocculant, leading to a slower sludge settling rate. Summary of the Invention
[0005] In view of the problem that when using some sedimentation tanks to separate clean water and sludge, the sludge and the added precipitant do not mix quickly and thoroughly, the reaction rate of sludge and precipitant is slow, resulting in a slow sludge settling rate, this application proposes a sludge sedimentation tank and a method for sludge-water separation using the sludge sedimentation tank.
[0006] In the first aspect, this application proposes a sludge settling tank and adopts the following technical solution.
[0007] A sludge settling tank includes a tank body, an enclosing cylinder, a mixing tube, a rotary actuator, and a stirring rod. The enclosing cylinder is fixed inside the tank body; both its upper and lower ends are open; the mixing tube is fixed inside the enclosing cylinder; the upper end of the mixing tube is a feed inlet, and the lower end is a discharge outlet; the enclosing cylinder surrounds the discharge outlet at intervals; the rotary actuator is fixed to the tank body; the output end of the rotary actuator is connected to the stirring rod; and the stirring rod is inserted into the mixing tube.
[0008] By adopting the above technical solution, the stirring rod can rotate under the drive of the rotary driver, thereby stirring the sludge and precipitant injected into the mixing tube. Compared with the natural diffusion solution, this solution can make the sludge and precipitant mix more quickly, thereby accelerating the sludge aggregation reaction and allowing the solid components in the sludge to settle quickly, thereby improving the sludge treatment efficiency.
[0009] A preferred embodiment of the sludge settling tank is that the surrounding cylinder has a hollow neck, a hollow enlarged portion, a hollow belly, and a hollow constricted portion connected sequentially from top to bottom; the upper end of the neck is open; the lower end of the constricted portion is open; the enlarged portion gradually expands from the end connected to the neck to the end connected to the belly; the constricted portion gradually shrinks from the end connected to the belly to the end away from the belly; the outer wall of the neck is designed to be vertical; the outer wall of the enlarged portion is a first inclined annular surface facing upwards; the outer wall of the belly is designed to be vertical; and the outer wall of the constricted portion is a second inclined annular surface facing downwards.
[0010] By employing the above technical solution, sludge is reacted with a precipitant in a mixing tube. The settled sludge falls from the lower end of the converging section into the bottom of the tank. Under continuous feeding conditions and water pressure, water can move upward along the outer wall of the converging section. This upward-moving water also pushes the water between the surrounding cylinder and the tank upward. This water moves upward through the outer walls of the converging section, the belly, the enlarged section, and the neck, respectively, thus separating some water from the sludge. The supernatant can be discharged through overflow or extraction from the top of the tank. Objects in the sludge with a density less than water can float to the water surface at the upper opening of the neck and the upper water surface between the surrounding cylinder and the tank, and are thus collected, rather than remaining inside the settling tank. At the same time, a small amount of sludge carried upward by the water can easily move downward along the vertical outer wall of the neck, the inclined outer wall of the enlarged section, the vertical outer wall of the belly, and the inclined outer wall of the converging section, falling back to the bottom of the tank, thereby effectively separating the sludge from the water and removing floating matter.
[0011] A further preferred embodiment of the sludge settling tank with the above-described surrounding cylinder is that the neck and the belly are coaxial cylinders; the tank body has a cylindrical shell section; the neck and the belly are both installed at the center of the cylindrical shell section; the distance L1 from the outer wall of the neck to the inner wall of the cylindrical shell section is 3 to 10 times the distance L2 from the outer wall of the belly to the inner wall of the cylindrical shell section.
[0012] By adopting the above technical solution: the space between the upper part of the surrounding cylinder and the tank is large, and the water storage is large, so more supernatant can be separated; the space between the lower part of the surrounding cylinder and the tank is small, and with the meandering channel formed by the narrowing section, the flow path of the disturbed liquid below can be extended, increasing the chance of solids settling, so that the proportion of solids contained in the water flow passing between the belly and the tank is smaller.
[0013] A further preferred embodiment of the above-mentioned sludge settling tank is that the sludge settling tank further includes a drainage mechanism; the water inlet of the drainage mechanism is located at the upper part of the tank body; the water inlet of the drainage mechanism faces the outer wall of the neck.
[0014] By adopting the above technical solution, water is drawn from the neck and flows along the outer wall of the neck towards the water inlet. The water flowing here is deviated from the channel between the abdomen and the tank body, and the suction force on the water between the abdomen and the tank body is smaller, thereby reducing the disturbance to the sedimented mud and water at the bottom of the tank body and improving the efficiency of the sludge sedimentation tank in separating mud and water.
[0015] A further preferred embodiment of the above-mentioned sludge settling tank is that the drainage mechanism is an overflow pipe; the overflow pipe is inserted into the tank body, and the water inlet of the overflow pipe faces the outer wall of the neck of the surrounding cylinder; the radius of the neck is r, the radius of the belly is R, and the distance L3 from the water inlet of the overflow pipe to the outer wall of the neck is ≤ (Rr) / 2.
[0016] By adopting the above technical solution, the overflow water causes less disturbance to the mud and water at the bottom of the tank, resulting in a higher efficiency in separating mud and water in the sludge sedimentation tank.
[0017] A preferred embodiment of the sludge settling tank is that the sludge settling tank further includes a blocking component; the blocking component is fixed inside the surrounding cylinder; the blocking component is disposed below the discharge port; the outer surface of the blocking component is divided into an upper conical surface and a lower conical surface; the end of the upper conical surface with a larger diameter and the end of the lower conical surface with a larger diameter are connected to each other.
[0018] By adopting the above technical solution, the blocking component can better guide the sludge to move downwards at an angle, reduce the disturbance of the sludge discharged from the discharge port to the bottom sediment, and at the same time, the upper and lower surfaces of the blocking component are not prone to the accumulation of sediment and floating matter.
[0019] In a preferred embodiment of the sludge settling tank, the stirring rod includes a central rod and a plurality of side rods; one end of each side rod is fixed to the central rod, and the other end is inclined downward; the upper end of the central rod is connected to the rotary drive; and the lower end of the central rod is connected to the blocking member via a bearing.
[0020] By adopting the above technical solution, the resistance of water to the stirring rod is reduced. Meanwhile, the inclined side rod increases the stirring area, improving the mixing efficiency of sludge and precipitant. The rotation of the central rod is less prone to eccentricity and is more stable.
[0021] In a preferred embodiment of the sludge settling tank, the stirring rod includes a fan blade assembly; the outer diameter of the fan blade assembly is smaller than the inner diameter of the mixing pipe; the fan blade assembly is disposed between the discharge port and the blocking member.
[0022] By adopting the above technical solution, the stirring rod can be removed from the sludge settling tank for easy cleaning and repair. The fan blade assembly can efficiently throw the sludge and water discharged from the outlet in all directions, improving the sludge turnover efficiency.
[0023] In a preferred embodiment of the sludge settling tank, the inner wall of the abdominal section faces the fan blade assembly and the upper conical surface; the inner wall of the narrowed section faces the lower conical surface.
[0024] By adopting the above technical solution, the sludge thrown out by the fan blade assembly is blocked by the inner wall of the abdomen and can slide down along the upper cone surface, and then slide down and settle along the inner wall of the narrowing part. This design effectively reduces the disturbance of the violently disturbed sludge to the water between the surrounding cylinder and the tank, and reduces the energy of solid matter in the mud and water moving between the surrounding cylinder and the tank.
[0025] Secondly, this application proposes a mud-water separation method and adopts the following technical solution.
[0026] A sludge-water separation method, using the aforementioned sludge settling tank to separate a portion of the water from the sludge, includes:
[0027] Start the rotary driver and set it to repeatedly switch between clockwise and counterclockwise rotation, thereby driving the stirring rod to synchronously switch between clockwise and counterclockwise rotation;
[0028] Sludge and precipitant are injected from the feed inlet;
[0029] With the repeated stirring action of the stirring rod, the sludge and precipitant are fully mixed, and the solid sludge in the sludge reacts with the precipitant to form precipitated sludge.
[0030] Under the rotation of the fan blade assembly, the mixture of sediment and water is thrown out of the discharge port;
[0031] Under the blocking action of the blocking member and the surrounding restraint of the abdomen, the mixture of sediment and water moves downward along the inner wall of the narrowed part;
[0032] The sediment falls to the bottom of the tank under gravity, thereby squeezing the water upward; some water moves upward along the outer wall of the narrow section, and the water in the upper part of the tank flows out of the tank, thereby separating a portion of the water from the sludge.
[0033] By adopting the above technical solution, the stirring rod synchronously switches between clockwise and counterclockwise rotation, which improves the mixing reaction efficiency of sludge and precipitant. The surrounding cylinder and the blocking component reduce the disturbance of the sludge water thrown out by the fan blade assembly to the water between the surrounding cylinder and the tank, thereby improving the sludge settling efficiency. The supernatant in the upper part between the surrounding cylinder and the tank contains a low proportion of solids, which allows some of the water in the sludge to be separated efficiently.
[0034] In summary, the sludge settling tank and the method for separating sludge and water using the sludge settling tank of this application have the following beneficial effects: The sludge settling tank is equipped with a rotary drive and a stirring rod, which can stir the sludge and precipitant injected into the mixing tube. Compared with the solution of sludge and precipitant naturally diffusing and combining, this solution can make the sludge and precipitant mix thoroughly at a faster speed, thereby accelerating the aggregation reaction of sludge and precipitant, and enabling the solid components in the sludge to settle quickly, thereby improving the sludge treatment efficiency. Attached Figure Description
[0035] Figure 1 This is an external structural diagram of a sludge settling tank.
[0036] Figure 2 for Figure 1 A cross-sectional view of a sludge settling tank.
[0037] Figure 3 for Figure 2 A three-dimensional structural diagram of the surrounding cylinder inside the sludge settling tank.
[0038] Figure 4 for Figure 2 A three-dimensional structural diagram of the baffle and its surrounding connecting rods in a sludge settling tank.
[0039] Reference numerals: Tank 1; Enclosing cylinder 2; Mixing pipe 3; Rotary actuator 4; Support frame 401; Stirring rod 5; Neck 201; Enlarged section 202; Abdomen 203; Narrowed section 204; Sludge pipe 6; Sediment pipe 7; Cylindrical shell section 101; Conical shell section 102; Guardrail 103; U-shaped trough 104; Overflow pipe 8; Water inlet 801; Blocking component 9; Connecting rod 10; Upper conical surface 901; Lower conical surface 902; Central rod 501; Side rod 502; Fan blade assembly 503. Detailed Implementation
[0040] The sludge settling tank and sludge-water separation method of this application are described in detail below with reference to the accompanying drawings.
[0041] Please refer to Figure 1 and Figure 2 A sludge settling tank includes a tank body 1, a surrounding cylinder 2, a mixing pipe 3, a rotary actuator 4, and a stirring rod 5.
[0042] The surrounding cylinder 2 is fixed inside the tank body 1. Both the upper and lower ends of the surrounding cylinder 2 are open. The mixing pipe 3 is fixed inside the surrounding cylinder 2. The upper end of the mixing pipe 3 is the feed inlet, and the lower end is the discharge outlet. The surrounding cylinder 2 surrounds the discharge outlet at intervals.
[0043] The rotary actuator 4 can be fixed to the tank 1 by a support frame 401. The rotary actuator 4 can be a motor or the like, and its output end is connected to a stirring rod 5. The stirring rod 5 is inserted into the mixing tube 3 to stir the mixture injected into the mixing tube 3.
[0044] In the above-mentioned sludge settling tank, sludge and precipitant are generally injected into the mixing tube 3. Driven by the rotary drive 4, the stirring rod 5 can rotate, thereby stirring the sludge and precipitant injected into the mixing tube 3. Compared with the solution of letting the sludge and precipitant diffuse and combine naturally, this solution can make the sludge and precipitant mix thoroughly at a faster speed, thereby accelerating the sludge aggregation reaction and allowing the solid components in the sludge to settle quickly, thereby improving the sludge treatment efficiency.
[0045] refer to Figure 3 To facilitate rapid sedimentation of the stirred slurry and minimize disturbance to the water between the surrounding cylinder 2 and the tank 1, this application designs a preferred structure for the surrounding cylinder 2. The surrounding cylinder 2 has, from top to bottom, a hollow neck 201, a hollow enlarged portion 202, a hollow belly 203, and a hollow constricted portion 204, connected sequentially. The neck 201 is open at its upper end; the constricted portion 204 is open at its lower end; the enlarged portion 202 gradually expands from the end connected to the neck 201 towards the end connected to the belly 203; the constricted portion 204 gradually narrows from the end connected to the belly 203 towards the end away from the belly 203; the outer wall of the neck 201 is designed to be vertical; the outer wall of the enlarged portion 202 is a first inclined annular surface facing upwards; the outer wall of the belly 203 is designed to be vertical; the outer wall of the constricted portion 204 is a second inclined annular surface facing downwards. The enlarged portion 202 and the constricted portion 204 can be frustum-shaped or pyramidal prism-shaped.
[0046] Based on the above-described structure of the surrounding cylinder 2, the process of treating sludge using this sludge settling tank can be as follows: Sludge is reacted with a precipitant added to the mixing pipe 3. The settled sludge falls from the lower end of the constriction section 204 into the bottom of the tank body 1. Under continuous feeding conditions and water pressure, water can move upward along the outer wall of the constriction section 204. The upward-moving water can also push the water between the surrounding cylinder 2 and the tank body 1 upward. This water moves upward through the outer walls of the constriction section 204, the belly 203, the expansion section 202, and the neck 201, respectively, so that some water in the sludge is separated out. The supernatant can be discharged through overflow or extraction from the top of the tank body 1. Objects in the sludge with a density less than water can float to the water surface at the upper opening of the neck 201 and the upper water surface between the surrounding cylinder 2 and the tank body 1, and thus be collected, rather than remaining inside the settling tank. At the same time, the small amount of sludge carried upward by the water can easily move downward along the vertical outer wall of the neck 201, the inclined outer wall of the enlarged part 202, the vertical outer wall of the abdomen 203, and the inclined outer wall of the narrowed part 204 and fall back to the bottom of the tank 1, thereby effectively separating the mud and water and separating the floating matter.
[0047] The aforementioned sludge settling tank may also include a sludge pipe 6 and a precipitant pipe 7. The outlet end of the sludge pipe 6 and the outlet end of the precipitant pipe 7 are both located in the mixing pipe 3, so that sludge and precipitant are injected into the mixing pipe 3 respectively.
[0048] A further preferred embodiment of the sludge settling tank with the aforementioned surrounding cylinder 2 is that the neck 201 and the belly 203 are coaxial cylindrical sections; the tank body 1 has a cylindrical shell section 101; both the neck 201 and the belly 203 are installed at the center of the cylindrical shell section 101; the distance L1 from the outer wall of the neck 201 to the inner wall of the cylindrical shell section 101 is 3 to 10 times the distance L2 from the outer wall of the belly 203 to the inner wall of the cylindrical shell section 101. The tank body 1 also has a conical shell section 102, integrally connected to the lower part of the cylindrical shell section 101. The bottom of the conical shell section 102 is the outlet for the settled sludge. The upper end of the tank body 1 may be provided with a guardrail 103, multiple U-shaped channels 104, etc. The guardrail 103 is fixed around the upper circumference of the cylindrical shell section 101. Each U-shaped channel 104 is provided on the upper surface of the tank body 1, arranged radially, connecting the cylindrical shell section 101, the surrounding cylinder 2, and the mixing pipe 3.
[0049] Besides being cylindrical, the neck 201 and abdomen 203 can also be coaxial prismatic or irregular columnar shapes, which also have vertical outer walls and are conducive to the settling of solids. This verticality can be completely vertical or a slightly inclined vertical outer wall that is smaller at the top and larger at the bottom, for example, with an inclination angle of 0~30° away from the vertical axis.
[0050] For the enclosing cylinder 2 with the above two distances L1 and L2, the large space between the upper part of the enclosing cylinder 2 and the tank body 1 allows for the storage of more water and the separation of a larger amount of supernatant. The small space between the lower part of the enclosing cylinder 2 and the tank body 1, combined with the meandering channel formed by the narrowing section 204, can extend the flow path of the disturbed liquid below, increase the chance of solids settling, and reduce the proportion of solids in the water flow passing between the abdomen 203 and the tank body 1.
[0051] The sludge settling tank may also include a drainage mechanism. The water inlet of the drainage mechanism is located at the upper part of the tank body 1. The water inlet of the drainage mechanism faces the outer wall of the neck 201, allowing water to be drawn from the neck 201. The water flows along the outer wall of the neck 201 towards the water inlet. The water flowing here is deviated from the channel between the belly 203 and the tank body 1, resulting in less suction on the water between the belly 203 and the tank body 1. This reduces disturbance to the sludge and water settling at the bottom of the tank body 1 and improves the efficiency of the sludge settling tank in separating sludge and water.
[0052] The drainage mechanism can be a combination of a water pump and a water pipe. The inlet end of the water pipe is located at the top of the tank 1, close to the outer wall of the surrounding cylinder 2.
[0053] The drainage mechanism can also be an overflow pipe 8, which automatically overflows to save energy. The overflow pipe 8 is inserted into the tank 1, and the water inlet 81 of the overflow pipe 8 faces the outer wall of the neck 201 surrounding the cylinder 2. The radius of the neck 201 is r, and the radius of the belly 203 is R. The distance L3 from the water inlet 81 of the overflow pipe 8 to the outer wall of the neck 201 is ≤ (Rr) / 2, which means that the water inlet 81 is deviated from the waterway between the belly 203 and the inner wall of the tank 1, and is biased towards the flow of water. This makes the disturbance of the overflow water to the mud and water at the bottom of the tank 1 smaller, and makes the sludge sedimentation tank more efficient in separating mud and water. Meanwhile, due to the structure of the surrounding cylinder 2 consisting of a neck 201, an enlarged portion 202, a belly 203, and a narrowed portion 204, the neck 201 is relatively concave inward and has a small diameter. This allows the overflow pipe 8 to be inserted inward close to the outer wall of the neck 201, and also allows the water inlet 81 of the overflow pipe 8 to be offset from the waterway of the belly 203 and the inner wall of the tank 1. This design reduces the suction force of the overflow water on the mud and water at the bottom of the tank 1, reduces the disturbance to the mud and water at the bottom, reduces the proportion of solids moving upward, and effectively separates mud and water. This design also increases the upper space between the surrounding cylinder 2 and the tank 1, increasing the amount of water that can be stored and improving the proportion of supernatant, making the sludge settling tank more effective at separating mud and water.
[0054] refer to Figure 2 To further reduce the disturbance of the sludge discharged from the mixing pipe 3 to the settled sludge at the bottom of the tank 1, a baffle 9 is also installed in the sludge settling tank. The baffle 9 is fixed within the surrounding cylinder 2. The baffle 9 is located below the discharge port. (Reference) Figure 4The outer surface of the baffle 9 is divided into an upper conical surface 901 and a lower conical surface 902. The baffle 9 is preferably a hollow structure. The larger diameter end of the upper conical surface 901 and the larger diameter end of the lower conical surface 902 are joined together. The upper conical surface 901 and the lower conical surface 902 can be smooth curved surfaces or pyramidal shapes. This baffle 9 can effectively guide the sludge to move downwards at an angle, reducing the disturbance of the sludge discharged from the discharge port to the bottom sediment. Simultaneously, the upper and lower surfaces of the baffle 9 are not prone to the accumulation of sedimented sludge and floating matter.
[0055] The surrounding cylinder 2 can be fixed to the tank body 1 by connecting rods 10. The mixing pipe 3 can be fixed to the surrounding cylinder 2 by connecting rods 10. The blocking member 9 can be fixed to the surrounding cylinder 2 by connecting rods 10.
[0056] One optional structure of the stirring rod 5 in the sludge settling tank is that the stirring rod 5 includes a central rod 501 and multiple side rods 502, which can be cylindrical rods. One end of each side rod 502 is fixed to the central rod 501, and the other end is inclined downwards; the upper end of the central rod 501 is connected to a rotary actuator 4. (Reference) Figure 4 A groove is formed at the top of the upper conical surface 901, and the lower end of the central rod 501 is connected to the blocking member 9 via a bearing, with the outer ring of the bearing fixed in this groove. Water provides less resistance to the stirring rod 5, and the inclined side rod 502 increases the stirring area, improving the mixing efficiency of sludge and precipitant. The rotation of the central rod 501 is less prone to eccentricity and is relatively stable.
[0057] To efficiently discharge the sludge-water reactants from the mixing pipe 3, the stirring rod 5 includes a fan blade assembly 503, which comprises three equidistant fan blades. The outer diameter of the fan blade assembly 503 is smaller than the inner diameter of the mixing pipe 3; the fan blade assembly 503 is positioned between the discharge port and the blocking member 9. This arrangement allows the stirring rod 5 to be removed from the sludge settling tank for easy cleaning and repair. The fan blade assembly 503 efficiently flings the sludge-water material discharged from the discharge port in all directions, improving the sludge turnover efficiency.
[0058] To further improve the settling efficiency of sludge, the inner wall of the abdomen 203 is designed to face the fan blade assembly 503 and the upper conical surface 901, and the inner wall of the narrowing part 204 faces the lower conical surface 902. In this way, the sludge thrown out by the fan blade assembly 503 is blocked by the inner wall of the abdomen 203 and can slide down along the upper conical surface 901, and then slide down along the inner wall of the narrowing part 204 to settle. This design effectively reduces the disturbance of the violently disturbed sludge to the water between the surrounding cylinder 2 and the tank 1, and reduces the energy of solids in the sludge-water moving between the surrounding cylinder 2 and the tank 1.
[0059] A sludge-water separation method, using the aforementioned sludge settling tank to separate a portion of the water from the sludge, includes:
[0060] Start the rotary driver 4 and set it to repeatedly switch between clockwise and counterclockwise rotation, thereby driving the stirring rod 5 to synchronously switch between clockwise and counterclockwise rotation;
[0061] Sludge and precipitant are injected from the feed inlet;
[0062] Under the repeated stirring action of the stirring rod 5, the sludge and the precipitant are fully mixed, and the solid sludge in the sludge reacts with the precipitant to generate precipitated sludge.
[0063] Under the rotation of the fan blade assembly 503, the mixture of sedimented mud and water is thrown out of the discharge port;
[0064] Under the blocking action of the blocking member 9 and the surrounding restraint of the abdomen 203, the mixture of sediment and water moves downward along the inner wall of the shrinkage section 204.
[0065] The sediment falls to the bottom of the tank 1 under the action of gravity, thereby squeezing the water upward; some of the water moves upward along the outer wall of the shrinkage section 204, and the water in the upper part of the tank 1 flows out of the tank 1, thereby separating a part of the water from the sludge.
[0066] In the above mud-water separation method, the stirring rod 5 synchronously switches between clockwise and counterclockwise rotation, which improves the mixing reaction efficiency of sludge and precipitant. The surrounding cylinder 2 and the blocking component 9 reduce the disturbance of the water between the surrounding cylinder 2 and the tank 1 caused by the mud and water thrown out by the fan blade assembly 503, thereby improving the sludge settling efficiency. The supernatant in the upper part between the surrounding cylinder 2 and the tank 1 contains a small proportion of solids, which allows some of the water in the sludge to be separated efficiently.
[0067] The sludge settling tank of this application is equipped with a rotary drive 4 and a stirring rod 5, which allows the sludge and precipitant to mix quickly and thoroughly, accelerating the aggregation reaction of the sludge and precipitant. On the other hand, it is equipped with an irregularly shaped surrounding cylinder 2, which reduces the disturbance of the rapidly moving sludge water to the bottom settling sludge and reduces the disturbance to the water between the surrounding cylinder 2 and the tank body 1, so that the solid components in the sludge can settle quickly and improve the sludge treatment efficiency.
[0068] The above are merely some embodiments of this application. The scope of protection of this application is not limited to the above embodiments. For those skilled in the art, any improvements and modifications made without departing from the inventive concept of this application also fall within the scope of protection of this application.
Claims
1. A sludge settling tank, characterized in that, It includes a tank (1), a surrounding cylinder (2), a mixing tube (3), a rotary drive (4), and a stirring rod (5); The surrounding cylinder (2) is fixed inside the tank body (1); the upper and lower ends of the surrounding cylinder (2) are both open; the mixing tube (3) is fixed inside the surrounding cylinder (2); the upper end of the mixing tube (3) is the feed inlet and the lower end is the discharge outlet; the surrounding cylinder (2) surrounds the discharge outlet at intervals; the rotary driver (4) is fixed on the tank body (1); the output end of the rotary driver (4) is connected to the stirring rod (5); the stirring rod (5) is inserted into the mixing tube (3); The surrounding cylinder (2) has a hollow neck (201), a hollow enlarged portion (202), a hollow belly (203), and a hollow constricted portion (204) connected sequentially from top to bottom; the upper end of the neck (201) is open; the lower end of the constricted portion (204) is open; the enlarged portion (202) gradually enlarges from one end connected to the neck (201) to one end connected to the belly (203); the constricted portion (204) gradually shrinks from one end connected to the belly (203) to one end away from the belly (203); the outer wall of the neck (201) is designed to be vertical; the outer wall of the enlarged portion (202) is a first inclined annular surface facing upwards; the outer wall of the belly (203) is designed to be vertical; the outer wall of the constricted portion (204) is a second inclined annular surface facing downwards; The sludge settling tank also includes a blocking component (9); the blocking component (9) is fixed in the surrounding cylinder (2); the blocking component (9) is located below the discharge port; the outer surface of the blocking component (9) is divided into an upper conical surface (901) and a lower conical surface (902); the larger diameter end of the upper conical surface (901) and the larger diameter end of the lower conical surface (902) are connected to each other; The stirring rod (5) includes a central rod (501) and a plurality of side rods (502); one end of each side rod (502) is fixed to the central rod (501), and the other end is inclined downward; the upper end of the central rod (501) is connected to the rotary driver (4); the lower end of the central rod (501) is connected to the blocking member (9) through a bearing. The stirring rod (5) includes a fan blade assembly (503); the outer diameter of the fan blade assembly (503) is smaller than the inner diameter of the mixing tube (3); the fan blade assembly (503) is disposed between the discharge port and the blocking member (9); The inner wall of the abdomen (203) faces the fan blade assembly (503) and the upper conical surface (901); the inner wall of the narrowing part (204) faces the lower conical surface (902). The surrounding cylinder (2) is fixed in the tank body (1) by some connecting rods (10); the mixing pipe (3) is fixed in the surrounding cylinder (2) by some connecting rods (10); the blocking member (9) is fixed in the surrounding cylinder (2) by some connecting rods (10).
2. The sludge settling tank according to claim 1, characterized in that, The neck (201) and the abdomen (203) are coaxial cylindrical; the tank body (1) has a cylindrical shell section (101); the neck (201) and the abdomen (203) are both installed at the center of the cylindrical shell section (101); the distance L1 from the outer wall of the neck (201) to the inner wall of the cylindrical shell section (101) is 3 to 10 times the distance L2 from the outer wall of the abdomen (203) to the inner wall of the cylindrical shell section (101).
3. The sludge settling tank according to claim 1 or 2, characterized in that, The sludge settling tank also includes a drainage mechanism; the water intake of the drainage mechanism is located at the upper part of the tank body (1); the water intake of the drainage mechanism faces the outer wall of the neck (201).
4. The sludge settling tank according to claim 3, characterized in that, The drainage mechanism is an overflow pipe (8); the overflow pipe (8) is inserted into the tank (1), and the water intake (81) of the overflow pipe (8) faces the outer wall of the neck (201) of the surrounding cylinder (2); the radius of the neck (201) is r, the radius of the abdomen (203) is R, and the distance L3 from the water intake (81) of the overflow pipe (8) to the outer wall of the neck (201) is ≤ (Rr) / 2.
5. A method for separating sludge and water, using the sludge settling tank of claim 1 to separate a portion of the water from the sludge, characterized in that, include: Start the rotary driver (4) and set the rotary driver (4) to repeatedly switch between clockwise and counterclockwise rotation, thereby driving the stirring rod (5) to switch between clockwise and counterclockwise rotation synchronously; Sludge and precipitant are injected from the feed inlet; Under the repeated stirring action of the stirring rod (5), the sludge and the precipitant are fully mixed, and the solid sludge in the sludge reacts with the precipitant to generate precipitated sludge. Under the rotation of the fan blade assembly (503), the mixture of sedimented mud and water is thrown out of the discharge port; Under the blocking action of the blocking member (9) and the surrounding restraint of the abdomen (203), the mixture of sediment and water moves downward along the inner wall of the narrowing part (204); The sediment falls into the bottom of the tank (1) under the action of gravity, thereby squeezing the water upward; a part of the water moves upward along the outer wall of the narrowing part (204), and the water in the upper part of the tank (1) flows out of the tank (1), thereby separating a part of the water in the sludge.