Secondary sedimentation tank system

Abstract

The utility model provides a secondary sedimentation tank system and belongs to the technical field of sewage treatment. The secondary sedimentation tank system comprises a water distribution area and a sedimentation area, the water distribution area and the sedimentation area are sequentially connected in the water flow direction, the water distribution area comprises a water distribution channel, the sedimentation area comprises a sedimentation tank, a water distribution wall is arranged between the water distribution channel and the sedimentation tank, water distribution holes are formed in the water distribution wall, a sludge hopper area is arranged on the lower portion of the sedimentation tank, and the sludge hopper area comprises a sludge hopper. Each sludge hopper is in a three-dimensional isosceles trapezoid shape with a wide upper part and a narrow lower part, the included angle between the inclined plane of the side edge of each sludge hopper and the horizontal plane is 55-60 degrees, the sludge hoppers are arranged in rows along the width direction and the length direction of the sedimentation tank and are fully distributed at the bottom of the tank, each sludge hopper is provided with a sludge discharge pipe, and each sludge discharge pipe is provided with a sludge discharge control valve; and each sludge discharge control valve is electrically connected with the PLC control system. The secondary sedimentation tank system disclosed by the utility model is wide in application range, good sedimentation effect can be guaranteed, and construction investment can be saved.

Description

Technical Field

[0001] The utility model relates to the technical field of sewage treatment, in particular to a secondary sedimentation tank system. Background Art

[0002] The secondary sedimentation tank is a sedimentation tank after the sewage is biologically treated. The function of the secondary sedimentation tank is to separate mud and water, clarify the mud-water mixture, concentrate the sludge, and return the separated sludge to the biological treatment section. The effect directly affects the water quality of the effluent and the concentration of the return sludge. If the sedimentation and concentration effect is not good, the activated sludge suspended matter will increase in the effluent, thereby increasing the BOD mass concentration of the effluent; at the same time, the concentration of the return sludge will also decrease, thereby reducing the concentration of the mixed liquid in the aeration tank, affecting the purification effect.

[0003] At present, most of the secondary sedimentation tanks in sewage treatment systems adopt central inlet and peripheral outlet, peripheral inlet and peripheral outlet radial flow secondary sedimentation tanks, and rectangular peripheral inlet and peripheral outlet secondary sedimentation tanks. These types of secondary sedimentation tanks must be equipped with scraper suction machines. At the same time, in order to ensure the mud and water separation effect, the surrounding water depth must be at least 4m, and most of them are about 4.5m. The construction diameter of the peripheral inlet and peripheral outlet radial flow secondary sedimentation tank must be greater than 20m. When the diameter is less than 20m, the sedimentation effect is not good. However, in some renovation projects, the above conventional secondary sedimentation tank forms cannot be applied due to issues such as land area, land shape or excavation depth.

[0004] Therefore, a secondary sedimentation tank system is urgently needed to solve the above problems. Utility Model Content

[0005] The utility model aims to provide a secondary sedimentation tank system, which is suitable for renovation or new construction projects with various land shapes and different excavation depths, can ensure good mud-water separation and sludge concentration effects, and can also save construction investment.

[0006] To achieve the above-mentioned purpose, the utility model provides a secondary sedimentation tank system, including a water distribution area and a sedimentation area, the water distribution area and the sedimentation area are connected in sequence along the water flow direction, the water distribution area includes a water distribution channel, the sedimentation area includes a sedimentation tank, a water distribution wall is arranged between the water distribution channel and the sedimentation tank, a water distribution hole is arranged on the water distribution wall, a clear water area is arranged at the upper part of the sedimentation tank, a water outlet trough is arranged at the side of the clear water area away from the water distribution area, a sludge bucket area is arranged at the lower part of the sedimentation tank, the sludge bucket area includes a sludge bucket, the sludge bucket is a three-dimensional isosceles trapezoidal shape that is wide at the top and narrow at the bottom, the angle between the side slope of the sludge bucket and the horizontal plane is 55° to 60°, there are a plurality of sludge buckets, and the plurality of sludge buckets are arranged in a row along the width direction and the length direction of the sedimentation tank and cover the bottom of the tank, each of the sludge buckets is provided with a sludge discharge pipe, each of the sludge discharge pipes is provided with a sludge discharge control valve, and each of the sludge discharge control valves is electrically connected to a PLC control system.

[0007] Compared with the prior art, the secondary sedimentation tank system of the utility model breaks the shackles of conventional circular and rectangular water tanks, is suitable for sites with various aspect ratios, can reduce the matching of traditional scraper and suction sludge machines, saves equipment investment, and has the advantages of safe and reliable operation and stable sedimentation effect, as follows:

[0008] (1) The sludge hopper of the utility model is in the shape of a three-dimensional isosceles trapezoid, which is wide at the top and narrow at the bottom, and the angle between its side slope and the horizontal plane is 55° to 60°. This arrangement improves the sludge concentration effect, increases the solid content of the return sludge, and further increases the sludge concentration of the biochemical system, ensuring the sewage treatment effect.

[0009] (2) The utility model has a plurality of sludge hoppers, which are arranged in a row along the length and width of the sedimentation tank and cover the bottom of the tank. Such an arrangement can reduce the total height of the tank, reduce the construction cost, and can be applied to more sites in terms of plane layout, with a wider range of applications.

[0010] (3) The sludge hopper of the utility model is provided with a sludge discharge pipe and a sludge discharge control valve connected to the outside of the secondary sedimentation tank system, and the sludge discharge control valve is electrically connected to the PLC control system. The PLC control system can be used to realize the sludge discharge of individual sludge hoppers in turn, thereby ensuring smooth and uniform sludge discharge.

[0011] As a preferred technical solution, there are multiple water distribution holes, and the multiple water distribution holes are evenly distributed on the water distribution wall.

[0012] As a preferred technical solution, the distance between two adjacent water distribution holes is 150 mm to 200 mm.

[0013] As a preferred technical solution, the diameter of the water distribution hole is 100 mm to 150 mm.

[0014] As a preferred technical solution, a water inlet is provided at one end of the water distribution channel.

[0015] As a preferred technical solution, a water outlet is provided at one end of the water outlet trough.

[0016] As a preferred technical solution, at least one water outlet trough is provided, and the water outlet trough is arranged parallel to the water distribution wall.

[0017] As a preferred technical solution, a manual mud discharge valve is also provided on the mud discharge pipe.

[0018] As a preferred technical solution, the secondary sedimentation tank system of the utility model further includes a sludge discharge main pipe, and the output end of the sludge discharge pipe is connected to the sludge discharge main pipe.

[0019] As a preferred technical solution, a mud discharge pump is provided on the mud discharge main pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic plan view of the upper layer of the secondary sedimentation tank system of the utility model;

[0021] Figure 2 It is a plan view of the lower layer of the secondary sedimentation tank system of the utility model;

[0022] Figure 3 It is a cross-sectional schematic diagram of the secondary sedimentation tank system of the utility model in the AA direction;

[0023] Figure 4 It is a cross-sectional schematic diagram of the secondary sedimentation tank system of the utility model in the BB direction;

[0024] Figure 5 It is a cross-sectional schematic diagram of the secondary sedimentation tank system of the utility model in the CC direction.

[0025] Explanation of component symbols: 100-secondary sedimentation tank system, 10-water distribution area, 11-water distribution channel, 12-water distribution wall, 121-water distribution hole, 13-water inlet, 20-sedimentation area, 21-sedimentation tank, 22-clean water area, 221-water outlet trough, 222-water outlet, 23-sludge hopper area, 231-sludge hopper, 232-sludge discharge pipe, 233-sludge discharge control valve, 234-PLC control system, 235-manual sludge discharge valve, 236-sludge discharge main pipe, 237-sludge discharge pump. DETAILED DESCRIPTION

[0026] In order to better illustrate the purpose, technical solution and beneficial effects of the utility model, the utility model will be further described below in conjunction with the accompanying drawings. It should be noted that the embodiments described below are only part of the embodiments of the utility model, not all of them.

[0027] The terms "include", "comprising", etc. used herein indicate the presence of the features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components. All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0028] In this document, unless otherwise specified, directional terms such as "upper", "lower", "left", "right", "inner", "outer", etc. are used to indicate the orientation or positional relationship based on the drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device, element or component referred to must have a specific orientation, be constructed or operate in a specific orientation. It should be understood that when the absolute position of the described object changes, the relative positional relationship they represent may also change accordingly. Therefore, these directional terms cannot be understood as limiting the present invention.

[0029] Please refer to Figure 1 and Figure 5 The utility model provides a secondary sedimentation tank system 100, including a water distribution area 10 and a sedimentation area 20, which are connected in sequence along the water flow direction. The water distribution area 10 includes a water distribution channel 11, and the sedimentation area 20 includes a sedimentation tank 21. A water distribution wall 12 is provided between the water distribution channel 11 and the sedimentation tank 21, and a water distribution hole 121 is provided on the water distribution wall 12. In the utility model, the muddy and water mixture in the water distribution channel 11 enters the sedimentation tank 21 through the water distribution hole 121 of the water distribution wall 12 to separate muddy and water and concentrate sludge.

[0030] like Figure 1 As shown, a plurality of water distribution holes 121 are provided, and the plurality of water distribution holes 121 are evenly distributed on the water distribution wall 12, and the spacing between two adjacent water distribution holes 121 is 150 mm to 200 mm. Specifically, the spacing between two adjacent water distribution holes 121 may be, but not limited to, 150 mm, 155 mm, 160 mm, 165 mm, 170 mm, 175 mm, 180 mm, 185 mm, 190 mm, 195 mm, 200 mm. The diameter of the water distribution hole 121 is 100 mm to 150 mm. Specifically, the diameter of the water distribution hole 121 may be, but not limited to, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm. With such arrangement, the flow rate of the mixed liquid can be controlled within the range of 0.1 m / s to 0.15 m / s. The uniform arrangement of the water distribution holes 121 can achieve uniform water distribution, thereby improving the mud-water separation effect.

[0031] like Figure 1 and Figure 3 As shown, a clear water area 22 is provided at the upper part of the sedimentation tank 21, and a water outlet trough 221 is provided on the side of the clear water area 22 away from the water distribution area 10. At least one water outlet trough 221 is provided, and the water outlet trough 221 is provided parallel to the water distribution wall. In this embodiment, two water outlet troughs 221 are provided, and the two water outlet troughs 221 are parallel to the water distribution wall and are arranged side by side on the side away from the water distribution area 10 to achieve uniform water collection and drainage.

[0032] like Figure 1 to Figure 4 As shown, a sludge bucket area 23 is provided at the lower part of the sedimentation tank 21. The sludge bucket area 23 includes a sludge bucket 231, which is a three-dimensional isosceles trapezoidal shape that is wide at the top and narrow at the bottom, and the angle between the side slope of the sludge bucket 231 and the horizontal plane is 55° to 60°. The design of the sludge bucket being wide at the top and narrow at the bottom can make the sludge settle better inside the sludge bucket, and further set the angle between the side slope of the sludge bucket and the horizontal plane at 55° to 60°, so that the deposited sludge can be more strongly compressed by gravity, thereby improving the concentration effect of the sludge, thereby improving the solid content of the return sludge, and ensuring the effect of sewage treatment. In this embodiment, the angle between the side slope of the sludge bucket and the horizontal plane is 55°.

[0033] like Figure 2 As shown, there are a plurality of sludge hoppers 231, which are arranged in a row along the width and length of the sedimentation tank 21 and spread all over the bottom of the tank. Spreading the sludge hoppers 231 all over the bottom of the sedimentation tank can reduce the total height of the tank body, reduce the engineering cost, and be applicable to more sites in the plane layout, with a wider range of applications.

[0034] Continue as Figure 2 As shown, each sludge hopper 231 is provided with a sludge discharge pipe 232, and each sludge discharge pipe 232 is provided with a sludge discharge control valve 233, and each sludge discharge control valve 233 is electrically connected to a PLC control system 234. With such a configuration, the sludge discharge control valves 233 located on the sludge discharge pipes 232 of the sludge hopper 231 can be opened in turn by the PLC control system 234, so that each sludge hopper 231 can discharge sludge in turn and periodically. The specific sludge discharge time and sludge discharge cycle can be adjusted by the PLC control program, thereby avoiding the adverse effects of inconsistent sludge discharge amounts of each sludge hopper 231 to the greatest extent. Further, as Figure 2 As shown, each mud discharge pipe 232 is also provided with a manual mud discharge valve 235. When the mud discharge control valve 233 fails and cannot operate, the mud discharge work of the sludge hopper 231 can be continued through the manual mud discharge valve 235, thereby improving the practicality of the secondary sedimentation tank system of the utility model.

[0035] The secondary sedimentation tank system of the present invention also includes a sludge discharge main pipe 236, the output end of the sludge discharge pipe 232 is connected to the sludge discharge main pipe 236, and a sludge discharge pump 237 is also provided on the sludge discharge main pipe 236. In the present embodiment, one end of the sludge discharge pipe 232 extends into the bottom of the sludge bucket 231 and is connected to the sludge bucket 231, and the other end is connected to the sludge discharge main pipe 236. Under the power of the sludge discharge pump 237, the sludge in the sludge bucket 231 enters the sludge discharge main pipe 236 through the sludge discharge pipe 232, and is transported to the biochemical system through the sludge discharge main pipe 236 to continue to participate in the reaction and perform sewage treatment. Among them, multiple sludge discharge pumps 237 can be provided, and in the present embodiment, two are provided. Such a design allows that when one of the sludge discharge pumps 237 fails, other sludge discharge pumps 237 can be used to replace it, thereby improving the operational stability of the secondary sedimentation tank system of the present invention.

[0036] like Figure 2 to Figure 4 As shown, in this embodiment, 4 sludge hoppers 231 are arranged along the length direction of the sedimentation tank, and 3 sludge hoppers 231 are arranged along the width direction of the sedimentation tank, and a total of 12 sludge hoppers 231 are arranged, and each sludge hopper 231 is equipped with a sludge discharge pipe 232, a manual sludge discharge valve 235, and a sludge discharge control valve 233. The sludge discharge pump 237 is in operation, and the 1# sludge discharge control valve 233 is opened through the PLC control system 234, and the 2# sludge discharge control valve 233 is opened after 5 minutes (the time can be adjusted by the PLC control system), and the 1# sludge discharge control valve 233 is closed at the same time, and the 2# sludge discharge control valve 233 is opened. After 5 minutes (the time can be adjusted by the PLC control system), the 3# sludge discharge control valve 233 is opened, and the 2# sludge discharge control valve 233 is closed at the same time; and the 12 sludge discharge control valves 233 are opened in turn, and the cycle is carried out later to ensure that each sludge hopper discharges sludge smoothly and evenly.

[0037] like Figure 1 As shown, a water inlet 13 is provided at one end of the water distribution channel 11, and a water outlet 222 is provided at one end of the water outlet trough 221. In this embodiment, the water inlet 13 is provided at the upper end of the water distribution channel 11, and the water outlet 222 is provided at the lower end of the water outlet trough 221. With such a design, the water inlet 13 and the water outlet 222 are staggered at both ends of the secondary sedimentation tank system, which increases the residence time of the mud-water mixture in the secondary sedimentation tank system, thereby improving the mud-water separation effect.

[0038] In the utility model, the biochemical system can be any biochemical system in the prior art, and the utility model does not limit the specific settings of its biochemical system (not shown in the figure); the PLC control system 234 is also any PLC control system in the prior art, which can realize functions such as controlling the start and stop and operation cycle of the mud discharge control valve, and the utility model does not specifically limit its specific control method and system configuration.

[0039] When the secondary sedimentation tank system of the present invention is in use, the mud-water mixture from the biochemical system (not shown in the figure) enters the water distribution area 10 from the water inlet 13, and is evenly distributed into the sedimentation area 20 through the water distribution holes 121 on the water distribution wall 12. The mixed liquid is subjected to mud-water separation and stratified sedimentation in the sedimentation area 20, and the clean water stays in the clean water area 21 and is discharged from the water collection tank 221 arranged in the clean water area 22 to the outside of the secondary sedimentation tank system for the next step of treatment. The sludge is precipitated into the sludge hopper area 23 at the bottom of the sedimentation tank 21, and the sludge is compressed by gravity in the sludge hopper 231, and the PLC control system 234 is used to discharge the sludge from the individual sludge hoppers 231 in turn, and the sludge is returned to the biochemical system (not shown in the figure) through the suction action of the sludge discharge pipe 232 and the sludge discharge pump 237.

[0040] Finally, it should be noted that what is disclosed above is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the scope of the patent application of the present invention are still within the scope covered by the present invention.

Claims

1. A secondary sedimentation tank system, comprising a water distribution area and a sedimentation area, characterized in that: The water distribution area and the sedimentation area are connected in sequence along the water flow direction, the water distribution area includes a water distribution channel, the sedimentation area includes a sedimentation tank, a water distribution wall is arranged between the water distribution channel and the sedimentation tank, a water distribution hole is arranged on the water distribution wall, a clear water area is arranged at the upper part of the sedimentation tank, a water outlet trough is arranged at the side of the clear water area away from the water distribution area, a sludge hopper area is arranged at the lower part of the sedimentation tank, the sludge hopper area includes a sludge hopper, the sludge hopper is a three-dimensional isosceles trapezoidal shape that is wide at the top and narrow at the bottom, the angle between the side slope of the sludge hopper and the horizontal plane is 55° to 60°, there are a plurality of sludge hoppers, the plurality of sludge hoppers are arranged in a row along the width and length directions of the sedimentation tank and cover the bottom of the tank, each of the sludge hoppers is provided with a sludge discharge pipe, each of the sludge discharge pipes is provided with a sludge discharge control valve, and each of the sludge discharge control valves is electrically connected to the PLC control system.

2. The secondary sedimentation tank system according to claim 1, characterized in that: There are multiple water distribution holes, and the multiple water distribution holes are evenly distributed on the water distribution wall.

3. The secondary sedimentation tank system according to claim 2, characterized in that: The distance between two adjacent water distribution holes is 150 mm to 200 mm.

4. The secondary sedimentation tank system according to claim 1, characterized in that: The diameter of the water distribution hole is 100 mm to 150 mm.

5. The secondary sedimentation tank system according to claim 1, characterized in that: A water inlet is arranged at one end of the water distribution area.

6. The secondary sedimentation tank system according to claim 1, characterized in that: A water outlet is arranged at one end of the water outlet trough.

7. The secondary sedimentation tank system according to claim 1, characterized in that: At least one water outlet trough is provided, and the water outlet trough is arranged parallel to the water distribution wall.

8. The secondary sedimentation tank system according to claim 1, characterized in that: The mud discharge pipe is also provided with a manual mud discharge valve.

9. The secondary sedimentation tank system according to claim 1, characterized in that: It also includes a mud discharge main pipe, and the output end of the mud discharge pipe is connected to the mud discharge main pipe.

10. The secondary sedimentation tank system according to claim 9, characterized in that: The mud discharge main pipe is provided with a mud discharge pump.

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