A dynamic water cushion type energy dissipation drop well

Abstract

This invention discloses a dynamic water cushion type energy dissipation drop manifold, belonging to the field of municipal drainage construction technology. The drop manifold comprises an inlet pipe and an outlet pipe connected to the top inlet and bottom outlet of the manifold shaft, respectively. A dynamic water cushion forming device is disposed within the manifold shaft. The dynamic water cushion forming device includes a guide plate, an energy dissipation groove, and an elastic stopper. The guide plate is inclined towards the bottom of the manifold shaft, with its two ends connected to the inner wall of the manifold shaft and the top of the energy dissipation groove, respectively. The energy dissipation groove is disposed within the manifold shaft, with a bottom hole at its bottom and an overflow hole on its side wall. The elastic stopper includes a conical plug and a spring. The spring is located directly below the bottom hole, with one end connected to the bottom surface of the manifold shaft and the other end connected to the conical plug. The tip of the conical plug penetrates the bottom hole, and the bottom surface is larger than the area of ​​the bottom hole. This invention can adapt to changes in flow rate, exhibiting different operating states for different flow rates. It provides excellent energy dissipation for large, medium, and small flow rates and is widely applicable to municipal drainage networks and water conservancy projects.

Description

Technical Field

[0001] This invention belongs to the field of municipal drainage construction technology, specifically relating to a dynamic water cushion type energy dissipation drop well. Background Technology

[0002] Currently, commonly used drop systems include water cushion drop systems and stepped drop systems, but they have certain limitations in actual operation. For example: The energy dissipation effect of traditional water cushion type energy dissipation wells is significantly affected by the flow rate. When the flow rate is low, sewage flows along the well wall, and the water cushion in the stilling basin plays almost no role in energy dissipation. When the flow rate is moderate, the water cushion in the stilling basin cannot completely cover the jet impact area, and the water flow will directly impact the concrete at the bottom of the well, resulting in poor energy dissipation and long-term damage to the well structure. When the flow rate is high, water cushion puncture is likely to occur. High-speed water flow hits the water cushion with great kinetic energy, and the impact force of the water flow will cause violent water turbulence, resulting in splashing water and destroying the integrity of the water cushion. At this time, the water flow penetrates the water cushion and directly impacts the bottom of the basin, resulting in poor energy dissipation.

[0003] The stepped drop system is constrained by engineering costs and land area. Its principle is to dissipate water energy through multiple cascades. Precise calculation of the step height is crucial. If a single step is too high, the kinetic energy of a single cascade cannot be fully dissipated by the step surface, causing the water to impact the next step or the bottom of the well at high speed, resulting in splashing water and odor emissions, and accelerating wear on the well structure. If the step height is too small, there will be too many steps, making it difficult for the water to detach from the step surface and fall freely. The water will flow along the step surface, lacking the strong energy dissipation effect of jet impact and water jump turbulence, relying solely on frictional energy dissipation, which reduces the energy dissipation effect. Furthermore, stepped drop systems involve large engineering projects, with costs far exceeding those of water cushion drop systems. Sufficient buffer space must be reserved for each step, resulting in a large land area, making them unsuitable for compact sites such as urban core areas and narrow factory areas.

[0004] Both traditional cushion-type and stepped-type drop structures face a high risk of siltation. Due to the unstable flow of rainwater, stepped drop structures easily trap suspended solids in sewage during low flow periods. Long-term accumulation will reduce the flow cross-section and decrease the energy dissipation effect. For traditional cushion-type drop structures, the water velocity decreases after impacting the water cushion, making it easy for suspended solids carried by sewage to settle. Long-term operation will reduce the effective depth of the water cushion in the stilling basin.

[0005] Maintenance difficulties and odor problems: Deposits tend to harden and are difficult to remove with conventional water flushing, requiring maintenance personnel to descend into the well for cleaning, but the narrow space inside the well makes this difficult. If used in a sewage network, the negative pressure zone at the bottom of the well will actively draw in air from above, mixing it with hydrogen sulfide and ammonia escaping from the sewage, filling the well with foul odor. Summary of the Invention

[0006] Technical problem solved: To address the above-mentioned technical problems, this invention provides a dynamic water cushion type energy dissipation drop well. The drop well can adapt to changes in flow rate and has different working states for different flow rates. It can play a good energy dissipation role for large, medium and small flow rates and is widely applicable to municipal drainage pipe networks and water conservancy projects.

[0007] Technical Solution: A dynamic water cushion type energy dissipation drop well includes an inlet pipe, a well shaft, an outlet pipe, and a dynamic water cushion forming device. The inlet pipe and outlet pipe are respectively connected to the top inlet and bottom outlet of the well shaft. The dynamic water cushion forming device is located inside the well shaft. The dynamic water cushion forming device includes a guide plate, an energy dissipation groove, and an elastic stopper. The guide plate is inclined towards the bottom of the well shaft, and its two ends are respectively connected to the inner wall of the well shaft and the top of the energy dissipation groove. The energy dissipation groove is located inside the well shaft, and its bottom has a bottom hole, and its side wall has an overflow hole. The elastic stopper includes a conical plug and a spring. The spring is located directly below the bottom hole, with one end connected to the bottom surface of the well shaft and the other end connected to the conical plug. The tip of the conical plug penetrates the bottom hole, and the bottom plane is larger than the area of ​​the bottom hole.

[0008] Preferably, the drop well further includes an exhaust pipe, with both ends of the exhaust pipe respectively located on the well wall above and below the guide plate.

[0009] Preferably, the energy dissipation tank of the dynamic water cushion forming device is supported by a bottom support body at a certain height above the bottom of the well.

[0010] Preferably, the overflow holes are provided in at least one row, and the overflow holes in the same row are distributed at equal intervals.

[0011] Preferably, the conical plug is conical, and the diameter of its bottom plane is not less than the diameter of the bottom hole.

[0012] Furthermore, the cone apex of the conical plug is on the same straight line as the center of the bottom hole.

[0013] Preferably, the vertical distance between the lowest point of the overflow hole and the plane where the bottom hole is located is greater than 0.5m.

[0014] Preferably, the longitudinal slope of the bottom of the well shaft is 2-5%.

[0015] Beneficial effects: The present invention has the following technical effects: (1) No water cushion is required from the stilling basin, avoiding water cushion failure and frequent maintenance caused by sludge accumulation. The lower end of the exhaust pipe is set in the gas collection area, which is located between the back of the dynamic water cushion forming device and the well. Part of the gas carried by the jet can be collected in this area and guided to the wellhead through the exhaust pipe, which increases the gas content in the upper space of the dynamic water cushion forming device, reduces the amount of gas carried by the water, and avoids the gas from accumulating in the downstream pipeline to form an air pocket, thereby reducing the generation of water hammer in the downstream pipeline and reducing the amount of odor escaping from the downstream inspection well.

[0016] (2) Multi-stage energy dissipation: The drop well is a dynamic multi-stage energy dissipation system. The water cushion formed by the water accumulation in the dynamic water cushion forming device, the elastic baffle, and the water cushion formed by the water accumulation at the bottom of the drop well all have energy dissipation effects. The thickness of the water cushion and the degree of spring compression change with the inflow of water. It can play a good energy dissipation role for different flow ranges and can solve the problem of unstable flow in the rainwater pipe network.

[0017] (3) The main energy dissipation facility is a dynamic water cushion forming device, which is made of stainless steel. It can be prefabricated, has high strength, and is easy to install and remove. When cleaning and maintenance are required, it can be lifted out by hooks, which solves the problem of long construction cycle and high cost of existing drop wells. Attached Figure Description

[0018] Figure 1 This is a plan view of the present invention; Figure 2 AA cross-section of dynamic water cushion energy dissipation drop well at medium flow rate; Figure 3 AA cross-section diagram of dynamic water cushion energy dissipation drop well at low flow rate; Figure 4 AA cross-sectional view of dynamic water cushion energy dissipation drop well under high flow rate; The numbers in the diagram represent the following: 1. Inlet pipe, 2. Well shaft, 3. Outlet pipe, 4. Guide plate, 5. Energy dissipation groove, 6. Bottom hole, 7. Overflow hole, 8. Conical plug, 9. Spring, 10. Vent pipe, 11. Bottom support; The arrows in the diagram indicate the direction of water flow. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Example 1

[0020] like Figures 1-4 As shown, a dynamic water cushion forming device type energy dissipation drop well includes an inlet pipe 1, a well shaft 2, an outlet pipe 3, and a dynamic water cushion forming device. The inlet pipe 1 and the outlet pipe 3 are respectively connected to the top inlet and the bottom outlet of the well shaft 2, and the dynamic water cushion forming device is located inside the well shaft 2. The dynamic water cushion forming device is made of stainless steel, and the well shaft 2 is constructed by masonry or concrete pouring.

[0021] The dynamic water cushion forming device includes a guide plate 4, an energy dissipation trough 5, and an elastic baffle. The guide plate 4 is inclined towards the bottom of the well shaft 2, and the inclination angle should not be too large. At low flow rates, the water flow can still flow along the wall after passing through the guide plate 4. The two ends of the guide plate 4 are connected to the inner wall of the well shaft 2 and the top of the energy dissipation trough 5, respectively, dividing the air in the drop well into upper and lower parts. The lower air will accumulate in the space between the back of the dynamic water cushion forming device and the well shaft 2 due to the obstruction between the dynamic water cushion forming device and the well shaft 2. The energy dissipation trough 5 is located inside the well shaft 2, with a bottom hole 6 at its bottom and an overflow hole 7 on its side wall. The bottom of the energy dissipation trough 5 is also provided with a bottom support body 11, which is a cuboid column that can support the energy dissipation trough 5 at a certain height. The elastic stopper includes a conical plug 8 and a spring 9. The spring 9 is located directly below the bottom hole 6, with one end connected to the bottom surface of the wellbore 2 and the other end connected to the conical plug 8, providing support for the conical plug 8. The magnitude of this support force can be automatically set according to Hooke's law and general formulas of mechanics of materials based on the opening requirements corresponding to different flow rates. The tip of the conical plug 8 penetrates the bottom hole 6, and the bottom plane is larger than the area of ​​the bottom hole 6. The conical plug 8, the spring 9, and the overflow hole 7 together achieve self-adjustment of the orifice opening of the bottom hole 6.

[0022] The drop well also includes an exhaust pipe 10, with its two ends located below the guide plate 4 and on the side wall of the well cylinder 2 near the well opening, respectively.

[0023] The conical plug 8 is conical, and the diameter of its bottom plane is not less than the diameter of the bottom hole 6; the apex of the conical plug 8 is collinear with the center of the bottom hole 6. Under no water pressure, most of the volume of the conical plug 8 is located inside the energy dissipation tank 5, blocking most of the flow area of ​​the bottom hole 6. This flow area increases with the height of the water cushion within the energy dissipation tank 5. When the water volume reaches a certain value, under the pressure of the water cushion and the impact of the incoming water, the conical plug 8 completely exits the energy dissipation tank 5. At this point, the lower flow area of ​​the dynamic water cushion forming device is the entire area of ​​the bottom hole 6.

[0024] The overflow holes 7 are distributed along the height direction of the energy dissipation groove 5, and several rows can be arranged on its side wall, with the overflow holes 7 in the same row distributed at equal intervals.

[0025] The vertical distance between the lowest point of the overflow hole 7 and the plane containing the bottom hole 6 is greater than 0.5m. This distance represents the thickness of the water cushion within the energy dissipation tank 5 at medium water flow rates. A water cushion thickness of at least 0.5m within the energy dissipation tank 5 is necessary to achieve a good energy dissipation effect for medium to high inflow rates. (See also...) Figure 2 and Figure 4Section AB: front energy dissipation, rectification, and rear air collection, with exhaust pipe 10 located in this area for easy exhaust and to prevent odor diffusion; Section BC: collision of upper and lower water flows, water dropletization, and overflow; Section CD: formation of dynamic water cushion for energy dissipation, with the height of sections BC and CD varying with the height of the water cushion; Section DE: elastic stopper self-adjusts the opening of bottom hole 6, and spring 9 converts a portion of the kinetic energy of the incoming water into elastic potential energy; Section EF: water cushion at the bottom of the drop well absorbs the energy of water falling from bottom hole 6 and sliding down the side wall of conical stopper 8, further dissipating energy.

[0026] The bottom longitudinal slope of the well shaft 2 is 2~5%, which achieves the goals of energy dissipation, scour prevention, siltation prevention, and maintenance-free operation. The dynamic water cushion forming device can be designed as a circle or a rectangle, but is generally set as a circle. The circular structure has uniform stress distribution and is easy to construct.

[0027] When the sewage flow is small or at the beginning of rain, the flow rate is low and the flow velocity is low, so a water cushion cannot be formed inside the dynamic water cushion forming device. The water flows along the well wall to the guide plate 4, and then along the guide plate 4 to the side wall of the energy dissipation tank 5. Then the water flows through the gap between the bottom hole 6 and the elastic baffle to the side of the conical plug 8. Finally, the water flows along the side of the cone into the bottom of the drop well. After a period of time, a thin water cushion is formed at the bottom of the drop well. The water cushion at the bottom of the well also plays a role in energy dissipation. The water flow does not hit the well body during the whole process, so it will not damage the structure of the drop well. The flow velocity of the outlet pipe 3 will be significantly reduced compared with the flow velocity of the inlet pipe 1, resulting in a good energy dissipation effect.

[0028] At medium water flow rates, after a period of operation, the water flowing into the dynamic water cushion forming device cannot flow out through the gap between the bottom hole 6 and the elastic stopper in time. A water cushion of a certain thickness will form within the energy dissipation tank 5 of the dynamic water cushion forming device. After the sewage flow stabilizes, a water cushion of medium thickness will also form at the bottom of the drop well. Under the pressure of the water cushion in the dynamic water cushion forming device, the conical plug 8 of the elastic stopper will be compressed downwards, increasing the gap between the bottom hole 6 and the elastic stopper, thus controlling the thickness of the water cushion in the energy dissipation tank 5 below the lowest row of overflow holes 7. Part of the kinetic energy of the water jetted from the inlet pipe 1 is absorbed by the water cushion, and part is converted into the elastic potential energy of the spring 9. Furthermore, after the water flows down the side wall of the conical plug 8 and falls into the water cushion at the bottom of the drop well, the kinetic energy of the water is further consumed. Finally, the flow velocity of the water flowing downstream is significantly reduced compared to the inlet flow velocity.

[0029] When the water volume is large, the water jet enters the dynamic water cushion forming device. Based on the medium water volume, spring 9 continues to compress downwards, further increasing the opening of the bottom hole 6 and increasing the thickness of the water cushion within the energy dissipation groove 5. Due to the large water volume, a thicker water cushion forms at the bottom of the drop well after a period of time. Part of the water jetting in through the inlet flows out through the bottom hole 6, and part flows out through the multiple overflow holes 7 of the dynamic water cushion forming device, both landing on the water cushion at the bottom of the well. Most of the kinetic energy of the water jetting in is dissipated by the water cushion within the dynamic water cushion forming device and the water cushion at the bottom of the drop well, with a portion converted into the elastic potential energy of spring 9. Therefore, the water flow velocity from the outlet pipe 3 is significantly reduced.

Claims

1. A dynamic water cushion type energy dissipation drop well, characterized in that, The system includes an inlet pipe (1), a well shaft (2), an outlet pipe (3), and a dynamic water cushion forming device. The inlet pipe (1) and the outlet pipe (3) are connected to the top inlet and bottom outlet of the well shaft (2), respectively. The dynamic water cushion forming device is located inside the well shaft (2). The dynamic water cushion forming device includes a guide plate (4), an energy dissipation groove (5), and an elastic baffle. The guide plate (4) is inclined towards the bottom of the well shaft (2), and its two ends are connected to the inner wall of the well shaft (2) and the top of the energy dissipation groove (5), respectively. The energy dissipation groove (5) is located inside the well shaft (2), and its bottom is provided with a bottom hole (6), and its side wall is provided with an overflow hole (7). The elastic baffle includes a conical plug (8) and a spring (9). The spring (9) is located directly below the bottom hole (6), with one end connected to the bottom surface of the well shaft (2) and the other end connected to the conical plug (8). The tip of the conical plug (8) penetrates the bottom hole (6), and the bottom plane is larger than the area of ​​the bottom hole (6).

2. The dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The drop well also includes an exhaust pipe (10), with both ends of the exhaust pipe (10) located on the side wall of the well cylinder (2) above and below the guide plate (4).

3. The dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The energy dissipation tank (5) of the dynamic water cushion forming device is erected by the bottom support (11) at a certain height from the bottom of the well.

4. A dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The overflow holes (7) are provided in at least one row, and the overflow holes (7) in the same row are distributed at equal intervals.

5. A dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The conical plug (8) is conical, and the diameter of its bottom plane is not less than the diameter of the bottom hole (6), and the cone apex of the conical plug (8) and the center of the bottom hole (6) are on the same straight line.

6. A dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The vertical distance between the lowest point of the overflow hole (7) and the plane where the bottom hole (6) is located is greater than 0.5m.

7. A dynamic water cushion type energy dissipation drop well according to claim 1, characterized in that, The bottom longitudinal slope of the well shaft (2) is 2-5%.

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