Sewage superposed sedimentation tank

Abstract

The present invention discloses a sewage superposed sedimentation tank, which comprises a tank body; a water inlet pipe is provided on the side wall of the tank body, and a circumferential inlet and circumferential outlet sedimentation area is arranged inside; the lower end of the circumferential inlet and circumferential outlet sedimentation area is communicated with the position of the tank body close to the lower end; the position close to the upper end in the circumferential inlet and circumferential outlet sedimentation area is connected to the bottom of the mixing area through a communicating pipe; the lower end of the mixing area is closed and the upper end is open, and a flocculation area is arranged outside; an inclined plate sedimentation area with the same shape as the tank body is arranged outside the flocculation area and is communicated with the inclined plate sedimentation area through an opening at the lower end; a perforated plate formed by arranging a plurality of inclined tubes side by side is arranged between the inner wall of the inclined plate sedimentation area and the outer wall of the flocculation area, and an annular water outlet trough is arranged at a position close to the upper end; the treated sewage is output through a water outlet pipe at the bottom of the annular water outlet trough; sludge discharge pipes are arranged at the bottom of the tank body and the bottom of the inclined plate sedimentation area, and the precipitated sludge is discharged through the sludge discharge pipes.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment, and particularly to an overlapping sedimentation tank for sewage. Background Art

[0002] With the improvement of the national discharge standard requirements for sewage treatment plants, most newly built sewage treatment plants need to meet the first-class A discharge standard. Therefore, in the design and construction process, sewage biological treatment and advanced treatment facilities are involved. Currently, for sewage treatment, the effluent from the secondary sedimentation tank of biological treatment is usually subjected to chemical coagulation and sedimentation after adding chemicals, and then further removes suspended solids, phosphorus and other pollutants in the sewage, and is discharged after reaching the first-class A discharge standard.

[0003] The existing advanced sewage treatment system mainly consists of a biological reaction tank, a secondary sedimentation tank, a coagulation inclined plate sedimentation tank, etc. Among them, the biological reaction tank generally adopts the activated sludge method, and the secondary sedimentation tank realizes the separation of mud and water. Most of the sludge is recycled. The effluent from the secondary sedimentation tank enters the coagulation inclined plate sedimentation tank, which consists of a coagulation reaction zone and an inclined plate sedimentation zone, and is a place where the coagulant is added to fully mix and contact with the organic pollutants in the sewage and then separate the mud and water. After being treated by the biological reaction tank, the secondary sedimentation tank and the coagulation inclined plate sedimentation system, the pollutants in the sewage can basically reach the first-class A discharge standard.

[0004] In the traditional sewage biological treatment and advanced treatment system, the secondary sedimentation tank and the coagulation inclined plate sedimentation tank are in two different structures, and the head loss caused by the connection of the pipelines or orifices inside and between each tank is relatively large, and a certain floor area is required. Especially in the construction of existing sewage treatment plants, for some areas with tight land use, the traditional sewage biological treatment and advanced treatment system is difficult to adapt.

[0005] Therefore, how to make the floor area smaller, the head loss smaller, the effective treatment volume of the pool higher and the operation and management more convenient has become an urgent technical problem to be solved by those skilled in the art. Summary of the Invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides an overlapping sedimentation tank for sewage, and the purpose is to solve the problems of large land use and high operation cost caused by many treatment structures and large head loss in the existing sewage biological and advanced treatment systems.

[0007] To achieve the above purpose, the present invention discloses an overlapping sedimentation tank for sewage, including a pool body; the pool body is open at the top and has a truncated conical shape with an inner diameter gradually decreasing with the increase of depth at the bottom;

[0008] A water inlet pipe for inputting sewage is provided on the side wall of the pool body near the upper opening;

[0009] An interval parallel to the inner wall of the pool body is provided inside the pool body, surrounding a circumferential inlet and outlet sedimentation area within the pool body;

[0010] The circumferential inlet and outlet sedimentation area is in a vertically arranged tubular structure, with its lower end communicating with the position of the pool body near the lower end, and the height of the upper end exceeding the water inlet pipe;

[0011] The position near the upper end within the circumferential inlet and outlet sedimentation area is connected to the bottom of the mixing area vertically arranged near the center of the pool body through a connecting pipe;

[0012] The mixing area is in a vertically arranged tubular structure with a closed lower end and an open upper end, and the height of the open upper end is above the water inlet pipe;

[0013] An interval parallel to the outer wall of the mixing area is provided outside the mixing area, surrounding a flocculation area outside the mixing area;

[0014] The flocculation area is in a vertically arranged tubular structure, and an inclined plate sedimentation area with the same shape as the pool body outside, that is, an open upper part and a truncated conical shape with an inner diameter gradually decreasing with the increase of depth at the bottom, is connected to the position near the lower part of the inclined plate sedimentation area through an opening at the lower end;

[0015] The sewage flowing out from the upper end of the mixing area enters the inclined plate sedimentation area from the position near the lower end of the flocculation area;

[0016] The upper ends of the flocculation area and the inclined plate sedimentation area are flush with the upper end of the circumferential inlet and outlet sedimentation area;

[0017] A perforated plate formed by arranging multiple inclined tubes side by side is provided between the inner wall of the inclined plate sedimentation area and the outer wall of the flocculation area;

[0018] When the sewage rises upward from the position near the lower end of the inclined tube sedimentation area and passes over the perforated plate, it flows obliquely upward through the perforated plate;

[0019] An annular water outlet trough is provided at the position near the upper end between the inner wall of the inclined plate sedimentation area and the outer wall of the flocculation area;

[0020] The treated sewage is output through a water outlet pipe at the bottom of the annular water outlet trough;

[0021] Sludge discharge pipes are provided at the bottom of the pool body and the bottom of the inclined plate sedimentation area, and the precipitated sludge is discharged through the sludge discharge pipes.

[0022] Preferably, between the pool body and the circumferential inlet and outlet sedimentation area, below the water inlet pipe and near the water inlet pipe, a water distribution channel surrounding the pool body is provided;

[0023] The influent pipe inputs the sewage into the tank body through the water distribution channel.

[0024] More preferably, the sewage enters the tank body downward through a number of diversion holes arranged around the inner side wall of the tank body at the bottom of the water distribution channel.

[0025] More preferably, a diversion groove is provided corresponding to each diversion hole below the water distribution channel.

[0026] Preferably, a water outlet channel is provided at a position near the upper end in the peripheral inlet and peripheral outlet sedimentation area, which is arranged around the inner wall of the peripheral inlet and peripheral outlet sedimentation area;

[0027] The upper end of the inner side wall of the water outlet channel is above the influent pipe, the bottom is below the influent pipe, and the bottom is connected to the communicating pipe.

[0028] Preferably, the cross-sections of the tank body, the flocculation area, the inclined plate sedimentation area and the peripheral inlet and peripheral outlet sedimentation area are all circular and are coaxially arranged.

[0029] Preferably, the tank body and the inclined plate sedimentation area respectively discharge the precipitated sludge through two sludge discharge pipes.

[0030] Preferably, the height of the upper end of the side wall of the annular water outlet trough is above the position where the influent pipe is located on the side wall of the tank body and below the upper end of the inner side wall of the water outlet channel.

[0031] Preferably, a water baffle is provided at the lower end of the flocculation area.

[0032] Advantages of the present invention:

[0033] The sewage superposition type sedimentation tank of the present invention solves the problems of large land occupation and high operation cost caused by many treatment structures and large head loss in the traditional sewage biological and advanced treatment systems, and realizes the invention purposes of reasonable layout of two sedimentation systems, small floor area, small head loss, high effective treatment volume of the pool, convenient operation management and economy and effectiveness.

[0034] The present invention combines the layout of the pool type with the technical characteristics of the sewage treatment hydraulic process. The volume, flow rate, etc. requirements of each treatment unit of the two sedimentations are different. By reasonably arranging the positions and shapes of each treatment unit according to the hydraulic process, the hydraulic flow in the pool is smooth, the water distribution is uniform, and the effective treatment volume of the pool is increased.

[0035] The present invention embodies the technical characteristics of the integration of sewage treatment systems. By arranging the coagulation reaction zone and the inclined plate sedimentation zone in the middle of the peripheral inlet and outlet sedimentation zone and sedimentation and filtration zone, the organic combination of the gravity separation of two different sludges and water is realized, changing the traditional sewage treatment method in which biological sedimentation and chemical coagulation sedimentation are carried out in different structures. This not only solves the problem of bottom sludge discharge of the two sedimentation tanks, but also minimizes the head loss, saves land, and reduces the operation cost and project investment.

[0036] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, features and effects of the present invention. Brief Description of the Drawings

[0037] Figure 1 A schematic structural diagram in the top view direction showing an embodiment of the present invention.

[0038] Figure 2 A schematic cross-sectional structural diagram in the longitudinal section showing an embodiment of the present invention. Detailed Description of the Invention Embodiment

[0039] As Figure 1 and Figure 2 shown, the sewage superimposed sedimentation tank includes a tank body 1; the tank body 1 is open at the upper part and has a truncated conical shape with an inner diameter gradually decreasing with the increase of depth at the bottom;

[0040] A water inlet pipe 8 for inputting sewage is provided on the side wall of the tank body 1 near the upper opening;

[0041] A circle of intervals parallel to the inner wall of the tank body 1 is provided inside the tank body 1, enclosing a peripheral inlet and outlet sedimentation zone 4 in the tank body 1;

[0042] The peripheral inlet and outlet sedimentation zone 4 is a vertically arranged tubular structure, the lower end is communicated with the position of the tank body 1 near the lower end, and the height of the upper end exceeds the water inlet pipe 8;

[0043] Near the upper end position in the peripheral inlet and outlet sedimentation zone 4, it is connected to the bottom of the mixing zone 6 vertically arranged near the center of the tank body through a connecting pipe 10;

[0044] The mixing zone 6 is a vertically arranged tubular structure with a closed lower end and an open upper end, and the height of the upper end opening is above the water inlet pipe 8;

[0045] A circle of intervals parallel to the outer wall of the mixing zone 6 is provided outside the mixing zone 6, enclosing a flocculation zone 5 around the mixing zone 6;

[0046] The flocculation zone 5 is arranged in a vertical tubular structure, and the external is provided with an inclined plate sedimentation zone 3 with the same shape as the pool body 1, that is, an opening at the upper part and a truncated conical shape with an inner diameter gradually decreasing with the increase of depth at the bottom, and is communicated with the lower part close to the lower end opening of the inclined plate sedimentation zone 3;

[0047] The sewage flowing out from the upper end of the mixing zone 6 enters the flocculation zone 5 from a position close to the lower end of the flocculation zone 5;

[0048] The upper end of the flocculation zone 5 and the upper end of the inclined plate sedimentation zone 3 are flush with the upper end of the peripheral inlet and outlet sedimentation zone 4;

[0049] A perforated plate 15 formed by arranging multiple inclined tubes side by side is provided between the inner wall of the inclined plate sedimentation zone 3 and the outer wall of the flocculation zone 5;

[0050] When the sewage rises upward from a position close to the lower end of the inclined plate sedimentation zone 3 and passes over the perforated plate 15, it flows obliquely upward through the perforated plate 15;

[0051] An annular water outlet groove 13 is provided between the inner wall of the inclined plate sedimentation zone 3 and the outer wall of the flocculation zone 5 at a position close to the upper end;

[0052] The treated sewage is output through a water outlet pipe 14 at the bottom of the annular water outlet groove 13;

[0053] A sludge discharge pipe 2 is provided at the bottom of the pool body 1 and a sludge discharge pipe 17 is provided at the bottom of the inclined plate sedimentation zone 3, and the precipitated sludge is discharged through the sludge discharge pipe 2 and the sludge discharge pipe 17 respectively.

[0054] The principle of the present invention is as follows:

[0055] The present invention combines the sewage treatment process characteristics of a secondary sedimentation tank and a coagulation sedimentation tank. According to the traditional layout method of discharging sewage from the secondary sedimentation tank to the coagulation sedimentation tank for chemical dosing and sedimentation, the completely isolated mode of the secondary sedimentation tank and the coagulation sedimentation tank is changed, so that the sewage biological treatment and chemical dosing and coagulation sedimentation can be completed in one structure, greatly reducing the head loss, reducing the sewage treatment structures, and solving the problems of more structures and large floor area in the traditional sewage biological treatment and chemical dosing and coagulation sedimentation systems.

[0056] In some embodiments, between the pool body 1 and the peripheral inlet and outlet sedimentation zone 4, below the water inlet pipe 8 and close to the water inlet pipe 8, a water distribution channel 7 is provided around the pool body 1;

[0057] The water inlet pipe 8 inputs the sewage into the pool body 1 through the water distribution channel 7.

[0058] In some embodiments, the sewage enters the pool body 1 downward through a plurality of diversion holes 11 provided around the inner side wall of the pool body 1 at the bottom of the water distribution channel 7.

[0059] In some embodiments, a diversion groove 12 is provided below the water distribution channel 7 corresponding to each diversion hole 11.

[0060] The existence of the above structure can evenly distribute the sewage introduced by the water inlet pipe 8.

[0061] In some embodiments, a water outlet channel 9 is provided in a position close to the upper end inside the peripheral inlet and peripheral outlet sedimentation zone 4 and is arranged around the inner wall.

[0062] The upper end of the inner side wall of the water outlet channel 9 is below the water surface of the peripheral inlet and peripheral outlet sedimentation zone 4, and the bottom is connected to the communicating pipe 10.

[0063] In some embodiments, the cross-sections of the pool body 1, the flocculation zone 5, the inclined plate sedimentation zone 3, and the peripheral inlet and peripheral outlet sedimentation zone 4 are all circular and are coaxially arranged.

[0064] In some embodiments, the pool body 1 and the inclined plate sedimentation zone 3 respectively discharge the precipitated sludge through two sludge discharge pipes 17.

[0065] In some embodiments, the height of the upper end of the side wall of the annular water outlet trough 13 is above the position where the water inlet pipe 8 is located on the side wall of the pool body 1 and below the upper end of the inner side wall of the water outlet channel 9.

[0066] In some embodiments, a water baffle 16 is provided at the lower end of the flocculation zone 5.

[0067] In practical applications, the working process of the present invention is as follows:

[0068] As Figure 1 and Figure 2 shown, the pool body 1 is a circular pool body, and the pool body 1 is divided into three annular unit treatment areas, namely a mixing zone 6, a flocculation zone 5, an inclined plate sedimentation zone 3, and a peripheral inlet and peripheral outlet sedimentation zone 4. The sewage enters from the upper part of the outer wall of the pool body 1 and is discharged from the water outlet trough 13 at the upper part of the inclined plate sedimentation zone 3 after biological sedimentation and chemical coagulation sedimentation.

[0069] The conical bottoms of the inclined plate sedimentation zone 3 and the peripheral inlet and peripheral outlet sedimentation zone 4 are sludge zones, and the precipitated sludge is respectively discharged from the pool body 1 through the sludge discharge pipe 2 and the sludge discharge pipe 17.

[0070] Since the areas and volumes required for the three annular unit treatment areas are different, the hydraulic power between the units is reasonably formed to flow from the outside to the center of the pool according to the technological process and the required flow rate, and then naturally diffuses vertically and radially. After passing through the water outlet trough 13 at the upper part of the inclined plate sedimentation zone 3, it is discharged.

[0071] The mixing zone 6, the flocculation zone 5, and the inclined plate sedimentation zone 3 are arranged in the middle of the peripheral inlet and peripheral outlet sedimentation zone 4, so that the organic combination of the gravity separation of two different sludges and water is realized, changing the traditional sewage treatment method in which biological sedimentation and chemical coagulation sedimentation are carried out in different structures, minimizing the head loss, saving land, and reducing the operation cost and project investment.

[0072] As shown by the arrows in the figure, the sewage enters from the water inlet pipe 8 at the upper part of the peripheral inlet and outlet sedimentation area 4. The water outlet channel 9 guides the water discharged after sedimentation in the peripheral inlet and outlet sedimentation area 4 into the lower part of the mixing area 6 through the connecting pipe 10. The sewage turns into the flocculation area 5 at the upper part of the mixing area 6, and then flows into the inclined plate sedimentation area 3 from the lower part of the flocculation area 5. After the sewage is sedimented from bottom to top, it is discharged through the water outlet pipe 14 by the annular water outlet trough 13 in the clear water area at the upper part of the inclined plate sedimentation area 3.

[0073] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should fall within the protection scope determined by the claims.

Claims

1. The sewage superposed sedimentation tank comprises a tank body (1); it is characterized in that The pool body (1) is open at the top and has a truncated conical shape at the bottom with an inner diameter gradually decreasing as the depth increases; A water inlet pipe (8) for inputting sewage is provided on the side wall of the pool body (1) near the upper opening; A ring of intervals parallel to the inner wall of the pool body (1) is provided inside the pool body (1), enclosing a circumferential inlet and circumferential outlet sedimentation area (4) inside the pool body (1); The circumferential inlet and circumferential outlet sedimentation area (4) is a vertically arranged tubular structure, with the lower end communicating with the position of the pool body (1) near the lower end, and the height of the upper end exceeding the water inlet pipe (8); Near the upper end position inside the circumferential inlet and circumferential outlet sedimentation area (4), it is connected to the bottom of a mixing area (6) vertically arranged near the center of the pool body through a connecting pipe (10); The mixing area (6) is a vertically arranged tubular structure with a closed lower end and an open upper end, and the height of the upper end opening is above the water inlet pipe (8); A ring of intervals parallel to the outer wall of the mixing area (6) is provided outside the mixing area (6), enclosing a flocculation area (5) around the mixing area (6); The flocculation area (5) is a vertically arranged tubular structure, and an inclined plate sedimentation area (3) with the same shape as the pool body (1), that is, open at the top and having a truncated conical shape at the bottom with an inner diameter gradually decreasing as the depth increases, is provided outside. It is communicated with the position near the lower part of the inclined plate sedimentation area (3) through the lower end opening; The sewage flowing out from the upper end of the mixing area (6) enters the inclined plate sedimentation area (3) from the position near the lower end of the flocculation area (5); The upper ends of the flocculation area (5) and the inclined plate sedimentation area (3) are flush with the upper end of the circumferential inlet and circumferential outlet sedimentation area (4); A perforated plate (15) formed by arranging multiple inclined tubes side by side is provided between the inner wall of the inclined plate sedimentation area (3) and the outer wall of the flocculation area (5); When the sewage rises upward from the position near the lower end of the flocculation area (5) and passes over the perforated plate (15), it flows upward obliquely through the perforated plate (15); An annular water outlet trough (13) is provided near the upper end position between the inner wall of the inclined plate sedimentation area (3) and the outer wall of the flocculation area (5); The treated sewage is output through a water outlet pipe (14) at the bottom of the annular water outlet trough (13); Sludge discharge pipes (17) are provided at the bottom of the pool body (1) and the bottom of the inclined plate sedimentation area (3), and the precipitated sludge is discharged through the sludge discharge pipes (17); The pool body (1) and the inclined plate sedimentation area (3) respectively discharge the precipitated sludge through two of the sludge discharge pipes (17); A water baffle (16) is provided at the lower end of the flocculation area (5); 2. The superimposed sedimentation tank for sewage according to claim 1, characterized in that, Between the pool body (1) and the circumferential inlet and circumferential outlet sedimentation area (4), below the water inlet pipe (8) and near the water inlet pipe (8), a water distribution channel (7) surrounding the pool body (1) is provided; The water inlet pipe (8) inputs the sewage into the pool body (1) through the water distribution channel (7); 3. The sewage superposed sedimentation tank according to claim 2, characterized in that, The sewage enters the pool body (1) downward through a number of diversion holes (11) provided at the bottom of the water distribution channel (7) and surrounding the inner side wall of the pool body (1).

4. The sewage superposed sedimentation tank according to claim 3, characterized in that, A diversion trough (12) is provided corresponding to each of the diversion holes (11) below the cloth water channel (7).

5. The sewage superposed sedimentation tank according to claim 1, wherein, An outlet channel (9) is provided at a position near the upper end inside the peripheral inlet and outlet sedimentation area (4) and is arranged around the inner wall of the peripheral inlet and outlet sedimentation area (4). The upper end of the inner side wall of the outlet channel (9) is below the water surface of the peripheral inlet and outlet sedimentation area (4), and the bottom is connected to the connecting pipe (10).

6. The sewage superimposed sedimentation tank according to claim 5, characterized in that The height of the upper end of the side wall of the annular outlet trough (13) is below the upper end of the inner side wall of the outlet channel (9).

7. The superimposed sewage sedimentation tank according to claim 1, wherein The cross-sections of the pool body (1), the flocculation area (5), the inclined plate sedimentation area (3) and the peripheral inlet and outlet sedimentation area (4) are all circular and are arranged coaxially.

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