阅读说明：本技术 一种市政排水系统 (Municipal drainage system ) 是由 宋伟 朱超云 于 2021-07-05 设计创作，主要内容包括：本发明公开了一种市政排水系统,市政排水系统包括箱涵和排水管,箱涵内设置有第一导流墙和第二导流墙,第一导流墙和第二导流墙将箱涵依次分隔形成粗砂沉淀池、细砂沉淀池和污泥沉淀池,粗砂沉淀池与细纱沉淀池的顶端相连通,污泥沉淀池的顶端与排水管相连通；第一导流墙上设有第一过滤孔,第二导流墙上设有第二过滤孔；第一导流墙的上方设有过滤网,过滤网的一侧与细砂沉淀池上方的箱涵内壁连接,过滤网的另一侧倾斜向下设置且位于粗砂沉淀池的上方。本发明市政排水系统,通过依次布设的粗砂沉淀池、细砂沉淀池和污泥沉淀池,对雨水中不同规格的砂粒进行过滤,有效阻止砂粒进入排水管,防止下水道的堵塞。(The invention discloses a municipal drainage system which comprises a box culvert and a drainage pipe, wherein a first guide wall and a second guide wall are arranged in the box culvert, the box culvert is sequentially divided by the first guide wall and the second guide wall to form a coarse sand sedimentation tank, a fine sand sedimentation tank and a sludge sedimentation tank, the coarse sand sedimentation tank is communicated with the top end of a spun yarn sedimentation tank, and the top end of the sludge sedimentation tank is communicated with the drainage pipe; a first filter hole is formed in the first flow guide wall, and a second filter hole is formed in the second flow guide wall; the top of first guide wall is equipped with the filter screen, and one side and the box culvert inner wall connection of fine sand sedimentation tank top of filter screen, the opposite side slope of filter screen sets up downwards and is located the top of coarse sand sedimentation tank. According to the municipal drainage system, the coarse sand sedimentation tank, the fine sand sedimentation tank and the sludge sedimentation tank are sequentially arranged to filter sand grains with different specifications in rainwater, so that the sand grains are effectively prevented from entering a drainage pipe, and a sewer is prevented from being blocked.)

1. The municipal drainage system is characterized by comprising a box culvert (1) and a drainage pipe (19), wherein a first guide wall (3) and a second guide wall (22) are arranged in the box culvert (1), the box culvert is sequentially divided into a coarse sand sedimentation tank (6), a fine sand sedimentation tank (11) and a sludge sedimentation tank (15) by the first guide wall (3) and the second guide wall (22), and the coarse sand sedimentation tank (6), the fine sand sedimentation tank (11) and the sludge sedimentation tank (15) are provided with top end openings; the top end opening of the coarse sand sedimentation tank (6) is communicated with the top end opening of the fine sand sedimentation tank (11), and the sludge sedimentation tank (15) is communicated with the inlet of the drain pipe (19); the top end of the box culvert (1) is provided with a first cover plate (27), and the first cover plate (27) covers the top end opening of the sludge sedimentation tank (15); the first guide wall (3) is provided with a first filtering hole (5), and the second guide wall (22) is provided with a second filtering hole (21); the top of first guide wall (3) is equipped with filter screen (25), box culvert (1) inner wall connection of one side and fine sand sedimentation tank (11) top of filter screen (25), the opposite side slope of filter screen (25) sets up downwards and is located the top of coarse sand sedimentation tank (6).

2. The municipal drainage system according to claim 1, wherein a settling pipe (20) is provided in the sludge settling tank (15); the sedimentation pipe (20) is obliquely arranged, and the inclination angle is 60 degrees; the top end of the settling pipe (20) is lower than the bottom end of the drain pipe (19), and the bottom end of the settling pipe (20) is higher than the second filtering hole (21).

3. The municipal drainage system according to claim 1, wherein the filter screen (25) is hinged to the inner wall of the culvert (1).

4. The municipal drainage system according to claim 1, wherein a first guide plate (2) is further disposed between the filter screen (25) and the top of the first guide wall (3), one end of the first guide plate (2) is connected to the free side of the filter screen (25), and the other end of the first guide plate (2) is connected to the top of the first guide wall (3).

5. The municipal drainage system according to claim 1, wherein a second deflector (4) is provided in the fine sand settling tank (11), the second deflector (4) being located below the first deflector (2); one side of the second guide plate (4) is connected with the inner wall of the box culvert (1), and a gap is reserved between the other side of the second guide plate (4) and the first guide wall (3).

6. The municipal drainage system according to claim 1, wherein the bottom end of the first guide wall (3) is provided with a first sand discharge port (10), and the coarse sand settling tank (6) is communicated with the bottom of the fine sand settling tank (11) through the first sand discharge port (10); the bottom end of the second guide wall (22) is provided with a second sand discharge port (13), and the bottoms of the fine sand sedimentation tank (11) and the sludge sedimentation tank (15) are communicated through the second sand discharge port (13).

7. The municipal drainage system according to claim 6, wherein the bottom of the sludge settling tank (15) is provided with a second slope (14), the bottom of the fine sand settling tank (11) is provided with a first slope (12), and the slope of the second slope (14) is greater than the slope of the first slope (12); a sand accumulation groove (9) is arranged at the bottom of the coarse sand sedimentation tank (6); a mud suction hopper (8) is arranged in the sand accumulation groove (9).

8. The municipal drainage system according to claim 6, wherein a flush pipe (17) is provided in the sludge settling tank (15).

9. The municipal drainage system according to claim 1, wherein an oxygen concentration sensor (18) is further disposed within the sludge settling tank (15).

10. The municipal drainage system according to claim 1, wherein the top end of the box culvert (1) is further provided with a second cover plate (26), the second cover plate (26) covering the top end openings of the coarse sand settling pond (6) and the fine sand settling pond (11); the second cover plate (26) is provided with a rainwater hole.

Technical Field

The invention belongs to the technical field of urban drainage waterlogging prevention engineering, and particularly relates to a municipal drainage system.

Background

A large amount of organic matters, heavy metals and solid pollutants are carried in initial rainwater runoff, along with the continuous acceleration of the urbanization process, the urban water system is seriously threatened, meanwhile, sundries which are washed off by rainwater are more, rainwater sundries carry a large amount of leaves and silt to enter a sewer pipeline together, the cleaning is difficult, the water cross section of a sewer is continuously reduced, and the municipal drainage capacity is continuously reduced.

Disclosure of Invention

The invention aims at the defects and provides a municipal drainage system which can effectively prevent solid substances such as sand grains and the like from entering a drainage pipe and prevent a sewer from being blocked.

In order to solve the technical problem, the embodiment of the invention adopts the following technical scheme:

the embodiment of the invention provides a municipal drainage system, which comprises a box culvert and a drainage pipe, wherein a first guide wall and a second guide wall are arranged in the box culvert, the box culvert is sequentially divided into a coarse sand sedimentation tank, a fine sand sedimentation tank and a sludge sedimentation tank by the first guide wall and the second guide wall, and the coarse sand sedimentation tank, the fine sand sedimentation tank and the sludge sedimentation tank are all provided with top end openings; the top end opening of the coarse sand sedimentation tank is communicated with the top end opening of the fine sand sedimentation tank, and the sludge sedimentation tank is communicated with the inlet of the drain pipe; the top end of the box culvert is provided with a first cover plate, and the first cover plate covers the top end opening of the sludge sedimentation tank; a first filter hole is formed in the first flow guide wall, and a second filter hole is formed in the second flow guide wall; the top of first guide wall is equipped with the filter screen, the box culvert inner wall connection of one side and fine sand sedimentation tank top of filter screen, the opposite side slope of filter screen sets up downwards and is located the top of coarse sand sedimentation tank.

As a further improvement of the embodiment of the invention, a sedimentation pipe is arranged in the sludge sedimentation tank; the sedimentation pipe is obliquely arranged, and the inclination angle is 60 degrees.

As a further improvement of the embodiment of the invention, the top end of the settling pipe is lower than the bottom end of the drain pipe, and the bottom end of the settling pipe is higher than the second filtering holes.

As a further improvement of the embodiment of the invention, the filter screen is hinged with the inner wall of the box culvert.

As a further improvement of the embodiment of the invention, a first guide plate is further arranged between the filter screen and the top end of the first guide wall, one end of the first guide plate is connected with the free side of the filter screen, and the other end of the first guide plate is connected with the top end of the first guide wall.

As a further improvement of the embodiment of the invention, a second guide plate is arranged in the fine sand sedimentation tank and is positioned below the first guide plate; one side of the second guide plate is connected with the inner wall of the box culvert, and a gap is formed between the other side of the second guide plate and the first guide wall.

As a further improvement of the embodiment of the present invention, the second baffle is an arc-shaped plate protruding upward.

As a further improvement of the embodiment of the invention, the bottom end of the first guide wall is provided with a first sand discharge port, and the coarse sand sedimentation tank is communicated with the bottom of the fine sand sedimentation tank through the first sand discharge port; and a second sand discharge port is formed in the bottom end of the second guide wall, and the bottoms of the fine sand sedimentation tank and the sludge sedimentation tank are communicated through the second sand discharge port.

As a further improvement of the embodiment of the invention, the bottom of the sludge sedimentation tank is provided with a second slope, the bottom of the fine sand sedimentation tank is provided with a first slope, and the bottom of the coarse sand sedimentation tank is provided with a sand accumulation groove; a sludge suction hopper is arranged in the sand accumulation groove.

As a further improvement of the embodiment of the invention, the slope of the second slope is greater than the slope of the first slope.

As a further improvement of the embodiment of the invention, a flushing pipe is arranged in the sludge settling tank.

As a further improvement of the embodiment of the invention, an oxygen concentration sensor is also arranged in the sludge settling tank.

As a further improvement of the embodiment of the invention, a second cover plate is further arranged at the top end of the box culvert and covers the top end openings of the coarse sand sedimentation tank and the fine sand sedimentation tank; and the second cover plate is provided with a rainwater hole.

Compared with the prior art, the technical scheme of the invention has the following beneficial effects: according to the municipal drainage system provided by the invention, through the coarse sand sedimentation tank, the fine sand sedimentation tank and the sludge sedimentation tank which are sequentially arranged, sand grains with different specifications in rainwater are filtered, the sand grains are effectively prevented from entering a drainage pipe, the blockage of a sewer is prevented, and the normal operation of the municipal drainage system is ensured.

Drawings

FIG. 1 is a schematic diagram of a municipal drainage system according to an embodiment of the invention.

The figure shows that: the box culvert 1, first guide plate 2, first guide wall 3, second guide plate 4, first filtration pore 5, coarse sand sedimentation tank 6, getter device 7, suction hopper 8, long-pending sand groove 9, first row of sand mouth 10, fine sand sedimentation tank 11, first slope 12, second row of sand mouth 13, second slope 14, mud sedimentation tank 15, wash mouthful 16, wash pipe 17, oxygen concentration sensor 18, drain pipe 19, sedimentation pipe 20, second filtration pore 21, second guide wall 22, second hinge 23, first hinge 24, filter screen 25, second apron 26, first apron 27.

Detailed Description

The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

The embodiment of the invention provides a municipal drainage system, which comprises a box culvert 1 and a drainage pipe 19, wherein the drainage pipe 19 is connected with one side of the box culvert 1, as shown in figure 1. The top end of the box culvert 1 is provided with an opening, and when raining, rainwater flows into the box culvert 1 from the opening. Vertically in the box culvert 1 be provided with first guide wall 3 and second guide wall 22, first guide wall 3 and second guide wall 22 separate the box culvert in proper order and form coarse sand sedimentation tank 6, fine sand sedimentation tank 11 and sludge sedimentation tank 15, first guide wall 3 is located between coarse sand sedimentation tank 6 and the fine sand sedimentation tank 11, second guide wall 22 is located between fine sand sedimentation tank 11 and the sludge sedimentation tank 15, coarse sand sedimentation tank 6, fine sand sedimentation tank 11 and sludge sedimentation tank 15 all have the top opening. The top of first guide wall 3 has the distance of predetermineeing apart from the top of box culvert 1 to the open-top of coarse sand sedimentation tank 6 is linked together with the open-top of fine sand sedimentation tank 11. The sludge settling tank 15 is communicated with the inlet of a drain pipe 19. The top of box culvert 1 is equipped with first apron 27, and first apron 27 covers the top opening of sludge sedimentation tank 15, and the entry that is located sludge sedimentation tank 15 top of box culvert 1 is sealed, and the entry that is located coarse sand sedimentation tank 6 and fine sand sedimentation tank 11 top of box culvert 1 still opens. A filter screen 25 is arranged above the first guide wall 3, one side of the filter screen 25 is connected with the inner wall of the box culvert 1 above the fine sand sedimentation tank 11, and the other side of the filter screen 25 is obliquely and downwards arranged and is positioned above the coarse sand sedimentation tank 6. The first guide wall 3 is provided with a first filtering hole 5, and rainwater in the coarse sand sedimentation tank 6 flows into the fine sand sedimentation tank 11 after being filtered by the first filtering hole 5. The second guide wall 22 is provided with a second filtering hole 21, and the rainwater in the fine sand sedimentation tank 11 flows into the sludge sedimentation tank 15 after being filtered by the second filtering hole 21. Preferably, the central height of the first filtering holes 5 is located at the middle upper portion of the first guide wall 3. In coarse sand sedimentation tank 6, the suspension coarse sand of the well upper portion height of first guiding wall 3 is less, and first filtration pore 5 is located this position, can prevent effectively that the coarse sand in coarse sand sedimentation tank 6 from entering into in the fine sand sedimentation tank 11.

The municipal drainage system of above-mentioned embodiment, rainwater are at first all through filter screen 25 in getting into box culvert 1 from box culvert 1's the entry that is located coarse sand sedimentation tank 6 and fine sand sedimentation tank 11 top, and the rainwater after the filtration mostly flows into fine sand sedimentation tank 11, and coarse sand and partial rainwater that the filter screen was held back flow into coarse sand sedimentation tank 6. After the rainwater in the coarse sand sedimentation tank 6 is primarily precipitated, the rainwater enters the fine sand sedimentation tank 11 after being filtered by the first filtering holes 5 on the first flow guide wall 3, and the floating objects in the rainwater cannot enter the fine sand sedimentation tank 11 due to the obstruction of the first flow guide wall 3. The rainwater in the fine sand sedimentation tank 11 is filtered through the second filtering holes 21 on the second guide wall 22 after being settled again, and then enters the sludge sedimentation tank 15. Rainwater in the sludge settling tank 15 flows upwards to the drain pipe 19, and fine solid matters such as sludge are basically not arranged in the drain pipe 19, so that the smoothness of a drain pipeline is ensured.

According to the municipal drainage system provided by the embodiment of the invention, the coarse sand sedimentation tank 6, the fine sand sedimentation tank 11 and the sludge sedimentation tank 15 are sequentially arranged to filter sand grains with different specifications in rainwater, so that the sand grains are effectively prevented from entering a drainage pipe, a sewer is prevented from being blocked, and the normal operation of the municipal drainage system is ensured.

Preferably, a settling pipe 20 is arranged in the sludge settling tank 15, and two ends of the settling pipe 20 are respectively fixed on the inner wall of the box culvert 1 and the second guide wall 22. Preferably, the height of the top end of the settling tube 20 is lower than the height of the bottom end of the drain tube 19. The sedimentation tube 20 in the sludge sedimentation tank 15 is used for further carrying out mud-water sedimentation separation, improves the filter effect for rainwater in the sludge sedimentation tank 15 all passes through the filtration of sedimentation tube 20 before entering into drain pipe 19, makes more tiny mud granule deposit in the bottom of sludge sedimentation tank 15, guarantees not that the precipitate gets into drain pipe 19, effectively prevents the jam of sewer. Preferably, the top end of the second filtering hole 21 is 500mm away from the bottom end of the settling tube 20. In the fine sand sedimentation tank 11, the suspended fine sand at the height of the position is less, and the fine sand in the fine sand sedimentation tank 11 can be effectively prevented from entering the sludge sedimentation tank 15. And the height of the bottom end of the settling pipe 20 is higher than that of the second filtering hole 21, so that rainwater flowing into the sludge settling tank 15 from the fine sand settling tank 11 through the second filtering hole 21 is filtered by the settling pipe 20 and then enters the drain pipe 19, and rainwater with fine solid precipitates in the fine sand settling tank 11 is prevented from directly entering the drain pipe 19. Further, the settling tube 20 is disposed obliquely at an angle of 60 degrees. The inclined setting of the sedimentation pipe 20 increases the sedimentation area, reduces the path of the sedimentation of suspended particles in water, improves the removal rate of suspended matters and hydraulic load, and shortens the sedimentation time.

Preferably, the filtering net 25 is hinged with the inner wall of the box culvert 1 through a first hinge 24. When the box culvert 1 needs manual cleaning or maintenance, the filter screen 25 can be turned, and the filter screen 25 rotates around the first hinge 24 and is attached to the inner wall of the box culvert 1, so that cleaning or maintenance of workers is facilitated.

Preferably, a first guide plate 2 is further arranged between the filter screen 25 and the top end of the first guide wall 3, one end of the first guide plate 2 is connected with the free side of the filter screen 25, and the other end of the first guide plate 2 is connected with the top end of the first guide wall 3. On the one hand, the free side of the filter screen 25 can be stabilized by the first guide plate 2, and the reliable use of the filter screen 25 is ensured. On the other hand, the rainwater filtered by the filter screen 25 can completely enter the fine sand sedimentation tank 11 after being guided and blocked by the first guide plate 2, and cannot enter the coarse sand sedimentation tank 6. The coarse sand that filter screen 25 was held back all gets into in coarse sand sedimentation tank 6 under the effect of blockking of first guide plate 2, and can not fall into fine sand sedimentation tank 11, realizes the high-efficient reposition of redundant personnel of coarse sand and rainwater after filtering.

Preferably, a second guide plate 4 is arranged in the fine sand sedimentation tank 11, and the second guide plate 4 is positioned below the first guide plate 2. One side of the second guide plate 4 is connected with the inner wall of the box culvert 1, and a gap is formed between the other side of the second guide plate 4 and the first guide wall 3. The rainwater filtered by the filter screen 25 falls on the second guide plate 4, so that the first-time speed reduction of the rainwater is realized, and the impact of the rainwater on the rainwater in the fine sand sedimentation tank 11 is reduced. Then, a part of the rainwater falling on the second guide plate 4 slides down along the surface of the second guide plate 4 and falls into the fine sand sedimentation tank 11, and the other part impacts the first guide wall 3, so that the second speed reduction of the rainwater is realized. Finally, one part of the rainwater impacting on the first guide wall 3 flows into the fine sand sedimentation tank 11 through a gap between the second guide plate 4 and the first guide wall 3 along the first guide wall 3, and the other part of the rainwater reversely impacts the lower part of the second guide plate 4 again and flows into the fine sand sedimentation tank 11 along the second guide plate 4, so that the third-time speed reduction of the rainwater is realized. The rainwater is buffered for three times, so that the impact force and the impact range of the rainwater on the water in the fine sand sedimentation tank 11 are effectively reduced, the stirring of the rainwater on sand grains at the bottom of the tank is slowed down, the fine sand at the bottom of the tank cannot float upwards, and the rainwater cannot enter the sludge sedimentation tank 15. Preferably, the second baffle 4 is arranged on the inner wall of the box culvert 1 through a second hinge 23 for cleaning or maintenance convenience.

Further, the second baffle 4 is an arc-shaped plate protruding upwards. The rainwater buffering is facilitated, and meanwhile, fine sand grains in rainwater are effectively prevented from being gathered on the second flow guide plate 4.

Preferably, the bottom end of the first guide wall 3 is provided with a first sand discharge port 10, and the coarse sand sedimentation tank 6 is communicated with the bottom of the fine sand sedimentation tank 11 through the first sand discharge port 10. The bottom end of the second guide wall 22 is provided with a second sand discharge port 13, and the bottoms of the fine sand sedimentation tank 11 and the sludge sedimentation tank 15 are communicated through the second sand discharge port 13. The sand grains precipitated at the bottom in the coarse sand sedimentation tank 6, the fine sand sedimentation tank 11 and the sludge sedimentation tank 15 can be gathered in the same tank through the first sand discharge port 10 and the second sand discharge port 13, and the cleaning is convenient.

Further, the bottom of the sludge sedimentation tank 15 is provided with a second slope 14, the bottom of the fine sand sedimentation tank 11 is provided with a first slope 12, and the bottom of the coarse sand sedimentation tank 6 is provided with a sand accumulation groove 9. The settled sand in the sludge settling tank 15 flows into the fine sand settling tank 11 through the second sand discharge port 13 along the second slope 14, the settled sand in the fine sand settling tank 11 flows into the coarse sand settling tank 6 through the first sand discharge port 10 along the first slope 12, and finally the settled sand in the three tanks is gathered in the sand accumulation tank 9, so that only the sand accumulation tank 9 needs to be cleaned, and the cleaning is convenient. Preferably, the slope of the second slope 14 is larger than that of the first slope 12, so that the sludge in the sludge settling tank 15 can move towards the sand accumulation groove 9 and can be finally accumulated in the sand accumulation groove 9.

Preferably, a mud suction hopper 8 is arranged in the sand accumulation groove 9. The mud suction hopper 8 is provided with an air suction device 7, the air suction device 7 lifts precipitated sand in the sand accumulation groove 9 out of the pool through compressed air with certain pressure, and a movable air compressor can be used for providing an air source to carry out air stripping on the precipitated sand.

Preferably, a flushing pipe 17 is arranged in the sludge settling tank 15. The flushing pipe 17 is connected with a movable air compressor, a flushing port 16 is arranged on the flushing pipe 17, and the flushing port 16 faces to the lower side of the sludge sedimentation tank 15. The provision of the flushing pipe 17 has two functions: firstly, wash the bottom of the pool deposit to mud sedimentation tank 15 and fine sand sedimentation tank 11 and sweep, compressed air promotes the deposit of bottom of the pool and moves forward, and the deposit of bottom of the pool loops through second sand discharge port 13 and first sand discharge port 10 and enters into long-pending sand groove 9. Secondly, the water in the pool is oxygenated through the flushing pipe 17, so that the oxygen content in the water is increased, the deterioration of the water is prevented, and the working environment is improved.

Preferably, an oxygen concentration sensor 18 is also arranged in the sludge sedimentation tank 15. The oxygen concentration sensor 18 is used to detect the oxygen content of the water in the tank, and the oxygen concentration sensor 18 may employ an oxygen sensor KE-25 of fegarro, japan. When the oxygen content in the water is lower than a set value, the rainwater in the box culvert is anoxic, the water body is easy to deteriorate, toxic and harmful gases such as hydrogen sulfide are generated, the working environment is poor, and at the moment, the water body at the bottom of the pond is oxygenated by connecting the movable air compressor, so that the water quality in the pond is improved.

Preferably, the top end of the box culvert 1 is further provided with a second cover plate 26, and the second cover plate 26 covers the top end openings of the coarse sand sedimentation tank 6 and the fine sand sedimentation tank 11, i.e. the inlet of the box culvert 1 above the coarse sand sedimentation tank 6 and the fine sand sedimentation tank 11 is covered by the second cover plate 26. The second cover plate 26 is provided with a rain water hole. When the rainwater passes through second apron 26 and gets into box culvert 1, the rainwater hole can prevent solid matter such as great branch, rubbish from entering into box culvert 1 in the rainwater, reduces the precipitate in the box culvert 1.

The operation of the municipal drainage system of the preferred embodiment described above is as follows:

when raining, the rainwater enters the box culvert 1 after the second cover plate 26 on the box culvert 1 filters out the sundries with larger volume. The filter screen 25 in the box culvert 1 filters the rainwater once more, and the coarse sand that the filter screen 25 held back gets off slides into the coarse sand sedimentation tank 6 along the filter screen 25 and under the blockking of first guide plate 2, falls into in the long-pending sand groove 9 of bottom of the pool. The rainwater filtered by the filter screen 25 flows to the fine sand sedimentation tank 11 under the diversion and blocking of the first diversion plate 2. Firstly, the rainwater filtered by the filter screen 25 falls on the second guide plate 4, so that the first-time speed reduction of the rainwater is realized, and the impact of the rainwater on the rainwater in the fine sand sedimentation tank 11 is reduced. Then, a part of the rainwater falling on the second guide plate 4 slides down along the surface of the second guide plate 4 and falls into the fine sand sedimentation tank 11, and the other part impacts the first guide wall 3, so that the second speed reduction of the rainwater is realized. Finally, one part of the rainwater impacting on the first guide wall 3 flows into the fine sand sedimentation tank 11 through a gap between the second guide plate 4 and the first guide wall 3 along the first guide wall 3, and the other part of the rainwater impacts the lower part of the second guide plate 4 again and flows into the fine sand sedimentation tank 11 along the second guide plate 4, so that the third-time speed reduction of the rainwater is realized. The rainwater is buffered for three times, the descending speed is greatly reduced, so that the impact force and the impact range of the rainwater on the water in the fine sand sedimentation tank 11 are effectively reduced, the stirring of the rainwater on sand grains at the bottom of the tank is slowed down, the fine sand at the bottom of the tank cannot float upwards, and the rainwater cannot enter the sludge sedimentation tank 15.

The rainwater in the coarse sand sedimentation tank 6 enters the fine sand sedimentation tank 11 after being filtered by the first filtering holes 5 on the first guide wall 3, and the floating objects in the coarse sand sedimentation tank cannot enter the fine sand sedimentation tank 11 due to the obstruction of the first guide wall 3. The rainwater in the fine sand sedimentation tank 11 enters the sludge sedimentation tank 15 after being filtered by the second filtering holes 21 on the second guide wall 22. The rainwater in the sludge sedimentation tank 15 flows upwards and is settled again through the sedimentation pipe 20, and the finer sand grains and the sludge in the water are further settled at the bottom of the tank. The clear water filtered by the settling pipe 20 flows upwards to the drain pipe 19, at this time, fine solid matters such as sludge are basically not present in the drain pipe 19, and therefore the smoothness of a drain pipeline is guaranteed.

After the rainwater stops, if the bottoms of the sludge sedimentation tank 15 and the fine sand sedimentation tank 11 need to be washed, the washing pipe 17 is connected to the movable air compressor, the compressed air is sprayed out through the washing port 16, on one hand, solid sediments such as sludge and fine sand grains at the bottom of the tank are washed, and the sludge and the fine sand enter the sand accumulation groove 9 through the second sand discharge port 13 and the first sand discharge port 10 in sequence along the second slope 14 and the first slope 12. On the other hand, as the rainwater stops, part of rainwater is still retained in the municipal drainage system, when solid precipitates such as sludge and sand at the bottom of the pool are washed, oxygen in the air enters the rainwater at the bottom of the pool, the oxygenation capacity of the rainwater is improved, and the phenomenon that the rainwater in the pool goes bad due to oxygen deficiency is effectively prevented. The air suction device 7 is connected to a movable air compressor, and at the moment, a sand suction hopper 8 lifts solid sediments such as sludge, sand grains and the like in a sand accumulation groove 9 out of the pool through compressed air with certain pressure.

When the rain is not rained for a long time, the water in the box culvert is seriously anoxic due to poor fluidity, and the oxygen concentration sensor 18 in the pond detects that the oxygen content in the water is lower than a set value and transmits a signal to the control system. The flushing pipe 17 is connected with a movable air compressor, compressed air with certain pressure is sprayed through the flushing port 16 to oxygenate the water body in the pool, so that the oxygen content in the water is increased, and the water quality and the working environment are improved.

The embodiments of the present invention are merely preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. That is, all equivalent changes and modifications made according to the content of the claims of the present invention should be regarded as the technical scope of the present invention.