Novel settling tank center feeding well

Abstract

The utility model discloses a novel center feeding well of a settling tank, and relates to the technical field of settling tanks, in particular to the novel center feeding well of the settling tank, which comprises the settling tank, a top plate is arranged at the top of the settling tank, a shaft body is arranged in the middle of the settling tank, and a center shaft body concentric with the shaft body is fixedly arranged below the top plate. A flow baffle is fixedly installed on the upper portion of the inner wall of the center shaft body, and a grating is fixedly installed on the lower portion of the inner wall of the center shaft body. According to the novel settling tank center feeding well, the flow baffle, the grating and the discharging cone are arranged in a matched mode, so that the novel settling tank center feeding well has the effects that materials can be fully mixed, the utilization rate of a flocculating agent is increased, and high-solid-content underflow is obtained; the novel center feeding well of the settling tank has the effects that materials can be uniformly and orderly discharged into the settling tank, and disturbance underflow is reduced as much as possible.

Description

Technical Field

[0001] This utility model relates to the field of settling tank technology, specifically a novel settling tank central feed well. Background Technology

[0002] The settling tank is an important settling device in the Bayer process of alumina production. Its purpose is to separate the material into a high-quality clarified liquid (i.e., sodium aluminate solution) and a high-solids-content precipitate (i.e., underflow). The working principle is that the material is introduced into the central well through a pipe or chute and mixed with flocculant. Then, the material is sent into the settling tank below the liquid surface through the lower part of the central well. The material will then be rapidly dispersed in the overall cross-section. As the liquid flows upward and the solid particles sink to the bottom of the settling tank, the liquid and solid are separated. Then, a slowly rotating rake gradually gathers the bottom sediment solids to the sludge outlet in the center of the bottom and continuously discharges them. The discharged thick sludge is called the underflow. In the end, the material is continuously fed in and out, and a high-quality solution with low suspended solids and a high-solids-content underflow are obtained.

[0003] The material enters the cylinder tangentially through the center of the central well. Under the impetus of a certain flow rate, the material and flocculant rotate at high speed and mix thoroughly. At this time, the material rapidly aggregates under the action of the flocculant and its specific gravity increases. Finally, it is evenly discharged from the bottom of the central well cylinder to minimize disturbance to the material outside the central well and achieve rapid liquid-solid separation. Therefore, the flocculation process of the material is completed in the central well, and the performance of the settling tank depends on the central well.

[0004] In existing technologies, the central well of settling tanks is mostly a straight cylinder discharge. The material and flocculant from the upstream process are mixed in the feed pipe or chute before entering the central well. After a brief residence time in the flow due to disturbance, the material enters the settling tank for sedimentation. The mixing effect of the material in the central well varies depending on the feed rate. If the feed rate is too large, the material rotates too fast in the central well, resulting in a short residence time. Most of the solids are contained in the solution and sink with the flow, while most of the unadsorbed flocculant flows out of the central well. The upper part of the central well is also not effectively utilized. If the feed rate is too small, the flow rate is too slow, and the material forms a parabolic short-circuit in the central well, flowing directly from the bottom of the central well cylinder. The flocculant is not fully mixed to exert an effective flocculation effect. Therefore, the current central well structure has some shortcomings in use. On the one hand, uneven mixing of materials leads to low solid content in the bottom flow of the settling tank and high flocculant consumption. On the other hand, the flow rate affects the direction of material discharge, causing eddies and disturbances in the bottom flow of the liquid in the settling tank. Utility Model Content

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this utility model provides a novel central feed well for settling tanks, which solves the problems mentioned in the background section.

[0007] (II) Technical Solution

[0008] To achieve the above objectives, this utility model is implemented through the following technical solution: a novel settling tank central feed well, including a settling tank, a top plate is provided at the top of the settling tank, a shaft is provided in the middle of the settling tank, a central well body concentric with the shaft is fixedly installed below the top plate, a baffle plate and a grid are fixedly installed on the inner wall of the central well body, a discharge cone is provided at the lower end of the central well body, a connector is fixedly installed on the outer side of the discharge cone, a material distribution cone is fixedly installed below the connector, and a feed trough is provided on the outer side of the central well body near the baffle plate.

[0009] Preferably, there are two baffles installed in staggered layers and spiraling downwards, which can lift the material to travel along a predetermined track, making the material close to the spiral flow direction, and achieving better and more complete flocculation.

[0010] Preferably, a number of grids are evenly placed on the outside of the baffle plate. The grids are welded from steel pipes. The grids can longitudinally intercept and disturb the material to make the material secondary fusion, which can achieve better full fusion and flocculation.

[0011] Preferably, a number of connectors are evenly distributed between the discharge cone and the distribution cone. The connectors are set at a certain angle to change the material flow direction. By cooperating with the distribution cone, the material can be evenly dispersed in all directions to expand the settling area and speed.

[0012] Preferably, the feed chute is tangent to the inner wall of the central well body, the outlet end of the feed chute is located above the baffle plate, and the feed chute is provided with a downward tilt angle to accelerate the flow of materials under the action of gravity.

[0013] Preferably, the settling tank is filled with liquid, and the central well body is immersed in the liquid. The central well body isolates the internal and external liquids and is connected only through the lower end of the discharge cone. The reduced diameter of the discharge cone can not only effectively increase the material residence time but also increase the flow rate.

[0014] This utility model provides a novel central feed well for a settling tank, which has the following beneficial effects:

[0015] 1. The new type of settling tank's central feed well, through the coordinated arrangement of baffles, grids, and discharge cones, enables the central feed well to achieve the effect of fully mixing materials, improving flocculant utilization, and obtaining high solids content underflow. The baffles effectively utilize the upper part of the central well to increase the material's residence time and improve the mixing effect. At the same time, the material is guided to rotate downwards along the wall and pass through the grid. The grid can further break up the initial material flocs, disperse the residual flocculant, and fully absorb and coagulate it again, thereby enabling the material to be fully mixed, improving flocculant utilization, and obtaining high solids content underflow.

[0016] 2. The new type of settling tank's central feed well, through the coordinated arrangement of baffles, discharge cones, connectors, distribution cones, and feed troughs, enables the central feed well to uniformly and orderly discharge materials into the settling tank, minimizing underflow disturbance. As the material is rapidly discharged onto the baffles through the feed trough tangent to the inner wall of the central well, regardless of the flow rate, the material is guided by the baffles to rotate downwards against the wall. Then, it falls into the discharge cone in the same motion and accelerates. Finally, it is guided by the connectors and distribution cones to uniformly diffuse into the liquid interior in the same motion. Because the material is discharged uniformly and moves in the same direction, underflow disturbance is reduced. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of the main view of this utility model;

[0018] Figure 2 This is a top view of the structure of this utility model;

[0019] Figure 3 This is a structural schematic diagram of the three-dimensional view of this utility model;

[0020] Figure 4 This is a structural schematic diagram of the cross-sectional view of this utility model.

[0021] In the diagram: 1. Settling tank; 2. Top plate; 3. Shaft; 4. Central shaft; 5. Baffle plate; 6. Grating; 7. Discharge cone; 8. Connecting piece; 9. Distribution cone; 10. Feed trough. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0023] Please see Figures 1 to 4This utility model provides a technical solution: a novel settling tank central feed well, including a settling tank 1, a top plate 2 at the top of the settling tank 1, a shaft 3 in the middle of the settling tank 1, a central well body 4 concentric with the shaft 3 fixedly installed below the top plate 2, baffles 5 and grids 6 fixedly installed on the inner wall of the central well body 4, the number of baffles 5 is two, installed in staggered layers and spiraling downwards, and the two baffles 5 can form a complete spiral when connected, the baffles 5 can lift the material to travel along a predetermined track, so that the material is close to the spiral flow direction, which can achieve better full fusion and flocculation, the number of grids 6 is several and evenly wrapped around the outside of the baffles 5, the grids 6 are welded from steel pipes, the grids 6 can longitudinally intercept and disturb the material to make the material secondary fusion, which can achieve better full fusion and flocculation, and a discharge cone 7 is provided at the lower end of the central well body 4, the outside of the discharge cone 7 is... A connector 8 is fixedly installed on the surface, and a feeding cone 9 is fixedly installed below the connector 8. Several connectors 8 are evenly distributed between the discharge cone 7 and the feeding cone 9. The connector 8 is set at a certain angle to change the material flow direction. Through the cooperation of the connector 8 and the feeding cone 9, the material can be evenly dispersed in all directions to expand the settling area and speed. A feed trough 10 is set on the outer side of the central well body 4 near the baffle plate 5. The feed trough 10 is tangent to the inner wall of the central well body 4. The outlet end of the feed trough 10 is located above the baffle plate 5. The feed trough 10 is set at a downward tilt angle to accelerate the flow of the material under the action of gravity. The interior of the settling tank 1 is filled with liquid, and the central well body 4 is immersed in the liquid. The central well body 4 is isolated from the internal and external liquids and is only connected through the lower end of the discharge cone 7. The reduced diameter of the discharge cone 7 can not only effectively increase the material residence time but also increase the flow rate.

[0024] During use, the mixture of material and coagulant enters the central well body 4 through the feed chute 10. Because the feed chute 10 has a downward inclination angle, the material enters the central well body 4 with a certain velocity. Since the feed chute 10 is tangential to the inner wall of the central well body 4, the material flows downwards along the inner wall. This flow velocity further propels the material to high-speed rotation. The material then falls onto the baffle plate 5. Because the baffle plate 5 also rotates downwards, the material, under its own gravity, is guided by the baffle plate 5 to continue accelerating and rotating downwards along the wall. The material is then thrown off the bottom of the baffle plate 5 and continues to rotate downwards along the inner wall. During this process, the material hits the grid 6, which longitudinally intercepts and disturbs the material, causing secondary fusion and achieving better and more complete flocculation. Finally, the material falls at a certain speed. As the material gradually decreases in diameter at the discharge cone 7, it not only effectively increases the material residence time but also increases the flow rate. Finally, the material is directed through the gap between the discharge cone 7 and the distribution cone 9 and diffuses evenly in all directions via the connector 8. Since the material is lifted and guided downward by the baffle plate 5 as soon as it enters the central well body 4, the movement trajectory is the same regardless of the flow rate. This ensures that the final discharge direction of the material does not change due to the flow rate, thus greatly reducing disturbance. The baffle plate 5 can also make full use of the space in the upper part of the central well body 4 and increase the material's residence time to improve the mixing effect between the flocculant and the material. After the solid particles of the material aggregate, their own specific gravity increases to achieve the liquid-solid separation effect. The central well can fully mix and flocculate the material and expand the settling area, improve the flocculant utilization rate, reduce the amount of secondary addition, and reduce the unit consumption.

[0025] In summary, this novel settling tank's central feed well, guided by the baffle plate 5, effectively utilizes the upper half of the central well to increase the material's residence time and improve mixing. Simultaneously, it guides the material to rotate downwards along the wall and pass through the grid 6. The grid 6 further breaks down the initial material flocs, dispersing residual flocculants and allowing for further coagulation. This results in thorough mixing of the material, improved flocculant utilization, and a high-solids-content underflow. Because the material is rapidly discharged onto the baffle plate 5 through the feed chute 10 tangential to the inner wall of the central well, regardless of flow rate, the material is guided downwards and rotates along the wall by the baffle plate 5. It then falls into the discharge cone 7 in the same motion and accelerates, before being guided by the connector 8 and the distribution cone 9 to diffuse evenly into the liquid interior. Since the material discharge is uniform and the direction of movement is consistent, it reduces disturbance to the underflow.

[0026] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A new type of central feedwell for a thickener, comprising a thickener (1), characterized in that: The top of the settling tank (1) is provided with a top plate (2), the middle of the settling tank (1) is provided with a shaft body (3), the lower side of the top plate (2) is fixedly installed with a center shaft body (4) concentric with the shaft body (3), the inner wall of the center shaft body (4) is fixedly installed with a flow baffle (5) and a grid (6), the lower end of the center shaft body (4) is provided with a discharge cone (7), the outer side of the discharge cone (7) is fixedly installed with a connecting piece (8), the lower side of the connecting piece (8) is fixedly installed with a distribution cone (9), and the outer side of the center shaft body (4) close to the upper side of the flow baffle (5) is provided with a feeding groove (10).

2. The new style central feedwell of a thickener according to claim 1, characterized in that: The number of the flow baffles (5) is two, which are installed in staggered layers and spiral downward, can hold the material to travel along the predetermined track, make the material approach the spiral flow direction, and can realize better full integration flocculation.

3. The new style central feedwell of a thickener according to claim 1, characterized in that: The number of the grids (6) is several and uniformly holds the outside of the flow baffles (5), the grid (6) is welded by steel pipes, the grid (6) can longitudinally intercept and disturb the material to make the material secondary integration, and can realize better full integration flocculation.

4. The new style central feedwell of a thickener according to claim 1, characterized in that: The number of the connecting pieces (8) is several and uniformly distributed between the discharge cone (7) and the distribution cone (9), the connecting piece (8) is provided with a certain angle to change the material flow direction, through the cooperation of the connecting piece (8) and the distribution cone (9), the material can be uniformly dispersed to the four directions to realize the expansion of the settling area and speed.

5. The new style central feedwell of a thickener according to claim 1, characterized in that: The feeding groove (10) is tangent to the inner wall of the center shaft body (4), the outlet end of the feeding groove (10) is located above the flow baffle (5), and the feeding groove (10) is provided with a downward inclination angle to make the material flow faster under the action of gravity.

6. The new style central feedwell of a thickener according to claim 1, characterized in that: The inside of the settling tank (1) is filled with liquid, the center shaft body (4) is soaked in the liquid, the center shaft body (4) isolates the inside and outside liquid and only communicates through the lower end of the discharge cone (7), and the small diameter of the discharge cone (7) can not only effectively increase the material residence time but also improve the flow rate.

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