Dredging system capable of automatically backwashing concave section of inverted siphon pipeline and using method thereof

Abstract

The invention provides a desilting system capable of automatically backwashing a concave section of an inverted siphon pipeline and a using method of the desilting system, and relates to the technical field of sewage pipe networks and water conveyance projects. The device comprises a water inlet pipeline, a water inlet distribution chamber, a grating, an overflow pipeline, a water inlet well gate, a water inlet well, a river water gate, a pipeline water inlet gate, an inverted siphon pipeline, a backwashing branch pipeline, a washing mask, a water outlet well, a pipeline water outlet gate, a water outlet well gate, a sludge pump, a sludge pipeline, a water outlet chamber, a water outlet pipeline, a liquid level meter, a PLC and the like. The mechanism that the backwashing branch pipes are arranged between the two inverted siphon pipelines and are communicated with each other is utilized for backwashing, and any backwashing device does not need to be additionally arranged.

Description

Technical Field

[0001] The invention relates to the technical field of sewage pipe networks and water delivery engineering, and in particular to a system for automatically backwashing and desilting a concave section of an inverted siphon pipe and a method for using the system. Background Art

[0002] When a water pipeline crosses a river, valley or road, if the pipeline cannot be crossed overhead and the downstream pipeline elevation must not be lowered, a pipeline layout plan with a local depression in the crossing area is generally adopted. This treatment method is an inverted siphon pipeline. Inverted siphon pipelines are widely used in sewage gravity flow pipelines and water pipelines, and have achieved good engineering benefits. However, sediments such as silt are easily accumulated in the concave part of the inverted siphon pipeline. At the same time, the concave pipeline is generally under the riverbed or road, and silt removal work cannot be carried out or silt removal is very difficult. The traditional method is to set up a grid and a silt trough in the water inlet section. In actual operation, due to the high silt content and difficulty in timely cleaning, the silt trough cannot meet the siltation demand, and the flow rate in the pipeline is low when the water flow is low for a long time, a large number of inverted siphon pipes are silted in the concave area. For this reason, a silt removal system that can automatically backwash the concave section of the inverted siphon pipeline is proposed.

[0003] The existing inverted siphon pipeline desilting technology is mainly based on installing mobile scrapers, sludge suction pumps, etc. in the inverted siphon pipeline. The main problems are as follows: ① The scraper will block the cross-section of the inverted siphon pipeline in the pipeline, affecting the flow capacity of the pipeline. If the pipeline is enlarged to reduce the obstruction of the cross-section, the flow rate in the pipeline will be too small, aggravating the sludge accumulation; ② The scraper is in the water for a long time, and the anti-rust and anti-corrosion requirements and protection level of the scraper are extremely high. If it is in sewage or corrosive water, the life of the scraper will be greatly affected; ③ There are many actual projects. The inverted siphon pipeline is buried deep, and the sludge is sucked and discharged by a sludge pump, which is greatly affected by the maximum suction capacity of the water pump. If the depth exceeds 4m, the sludge may not be pumped up; ④ The existing technologies are too complicated. Some require the arrangement of complex pipeline dredging devices, while others require the configuration of external suction pumps, air pumps and power supplies. The dredging is driven by an electric motor, which requires a high investment; ⑤ The existing technology cannot achieve automatic dredging, and dredging work needs to be achieved through manual cleaning or manual operation, and personnel need to conduct regular inspections to determine whether the dredging requirements have been met. Summary of the invention

[0004] The present invention provides a system for automatically backwashing and desilting the concave section of an inverted siphon pipe and a method for using the system, the purpose of which is to automatically backwash the sediment in the concave section of the inverted siphon pipe and overcome at least one technical problem of the existing inverted siphon pipe desilting technology mentioned in the background technology. Specifically, the present invention utilizes the liquid level difference between two inverted siphon pipes to achieve mutual backwashing and desilting; controls the opening and closing of the gates and the start and stop switching of the water pump between the pipes through a PLC program to achieve the formation of the backwashing liquid level difference; installs an online liquid level monitoring device to achieve regular and automatic backwashing of the inverted siphon pipe to prevent the sediment in the pipe from staying in the pipe for a long time and being compacted and solidified, making it impossible to clean; installs multiple backwash pipes between the two inverted siphon pipes to achieve dense coverage of the backwashing part at the bottom of the pipe, achieving good results.

[0005] The present invention adopts the following technical solutions to achieve the above purpose: A system for automatically backwashing and desilting the concave section of an inverted siphon pipe comprises an inlet distribution chamber, a grille is arranged in the inlet distribution chamber, the inlet distribution chamber is connected to an inlet pipe on one side of the grille, the upper part of the inlet distribution chamber is connected to an overflow pipe, and the middle part is connected to two inlet well gates on the other side of the grille, the two inlet well gates are respectively connected to an inlet well, and the inlet well is connected to a river water gate; the two inlet wells are respectively connected to one end of an inverted siphon pipe through the pipeline inlet gate, the two inverted siphon pipes are connected through a plurality of backwash branch pipes arranged at intervals, the backwash branch pipes are connected to the inverted siphon pipe from the bottom, the other ends of the two inverted siphon pipes are respectively connected to an outlet well through the pipeline outlet gate, the two outlet wells are respectively connected to an outlet chamber through the outlet well gate, the outlet chamber is connected to the outlet pipe, a sludge pump is arranged at the bottom of the outlet well, and the sludge pump is connected to the sludge pipe; liquid level gauges are respectively arranged in the inlet distribution chamber and the outlet well, and the liquid level gauges are electrically connected to a PLC.

[0006] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, a flushing mask is installed at the connection between the backwashing branch pipe and the inverted siphon pipe.

[0007] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, the flushing mask is arranged to be inclined toward the downstream side.

[0008] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, the backwashing branch pipes are arranged in equal spacing and parallel with a spacing of 2.5-3.5m.

[0009] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, the backwashing branch pipe is arranged below the inverted siphon pipe, and both ends are connected to the concave part at the bottom of the inverted siphon pipe through elbows, and the turning radius of the elbow is not less than 3 times the diameter of the backwashing branch pipe.

[0010] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, if the river water level exceeds the top of the inverted siphon pipe frequently, a river water gate is set on the inlet well and / or outlet well; otherwise, no river water gate is set.

[0011] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, the sludge pipe is connected to the outlet pipe and is arranged at a distance from the outlet chamber.

[0012] In the aforementioned automatic backwashing and dredging system for the concave section of the inverted siphon pipe, the inverted siphon pipe is inclined downward from the water inlet well to the water outlet well.

[0013] A method for using the system capable of automatically backwashing and desilting the concave section of an inverted siphon pipe comprises the following steps of backwashing and desilting the concave section of the inverted siphon pipe: S1: Open the water inlet gate, pipeline water inlet gate, pipeline water outlet gate and water outlet gate. After the system has been running for a period of time, when sediment accumulates in the inverted siphon pipe, the water flow section of the pipe will be reduced, the flow rate will increase and the head loss will increase. When the flow rate is large, the water level in the water inlet distribution room will rise. The water level data monitored by the liquid level meter in the water inlet distribution room is transmitted to the PLC in real time. When the water level data exceeds the maximum water level setting value, the PLC determines to start the backwashing program; S2: After the backwashing program is started, one of the two inverted siphon pipes is used as the flushed inverted siphon pipe, and the other is used as the flushing inverted siphon pipe; the PLC controls the corresponding water inlet well gates, water outlet well gates and river water gates at both ends of the flushed inverted siphon pipe to close, controls the corresponding pipe water inlet gates and pipe water outlet gates at both ends of the flushing inverted siphon pipe to close, starts the sludge pump in the outlet well corresponding to the flushed inverted siphon pipe, and pumps the water in the inlet well, outlet well and flushed inverted siphon pipe to be discharged through the sludge pipe; S3: When the water in the flushed inverted siphon pipe is pumped up and emptied to the lowest liquid level, the water level data transmitted to the PLC by the liquid level meter is lower than the lowest water level setting value, and the PLC controls to stop the sludge pump, and opens the corresponding inlet well gates and outlet well gates at both ends of the flushing inverted siphon pipe, and uses the water in the inlet pipe to fill the flushing inverted siphon pipe and the corresponding inlet wells, outlet wells, inlet distribution chambers, and outlet chambers with flushing water; when the river water gate is set, the PLC also opens the corresponding river water gate to use the river water to assist in filling the flushing water; S4: When the water level in the well chamber corresponding to the flushing inverted siphon pipeline and its two ends rises to the highest water level, the water level data transmitted to the PLC by the liquid level gauge in the corresponding outlet well reaches the set water level data after being judged by the PLC, and the PLC controls to first open the pipeline water inlet gate and pipeline water outlet gate corresponding to the two ends of the flushed inverted siphon pipeline, and then quickly open the pipeline water inlet gate and pipeline water outlet gate corresponding to the two ends of the flushing inverted siphon pipeline, and the flushing water stored in the well chamber corresponding to the two ends of the flushing inverted siphon pipeline enters the flushing inverted siphon pipeline and then hydraulically backwashes the concave part at the bottom of the flushed inverted siphon pipeline through the backwashing branch pipeline; S5: When the hydraulic backwashing continues until the water levels in the well chambers corresponding to both ends of the two inverted siphon pipes 9 reach equilibrium, the water level data transmitted to the PLC by the level gauges in the two outlet wells are consistent, and the backwashing program is ended through PLC control, and the corresponding pipe water inlet gates, pipe water outlet gates and river water gates at both ends of the backwashing inverted siphon pipes are closed, and the corresponding sludge pumps are started to pump up all the sludge in the flushed inverted siphon pipes and discharge them through the sludge pipes; S6: After the sludge pump has completed pumping up the sludge in the flushed inverted siphon pipe, the corresponding inlet well gates and outlet well gates at both ends of the flushed inverted siphon pipe are opened, and the corresponding pipe inlet gates and pipe outlet gates at both ends of the backwashing inverted siphon pipe are opened to restore the system to normal operation.

[0014] The aforementioned method for using the automatic backwashing and desilting system for the concave section of the inverted siphon pipe also includes setting the number of flushing times according to the actual flushing effect, and repeating steps S1-S6 for multiple flushings.

[0015] The present invention provides a system for automatically backwashing and desilting the concave section of an inverted siphon pipe, which has at least the following beneficial effects compared with the prior art: 1. The backwashing of the present invention utilizes the mechanism of interconnection of backwashing branches arranged between two inverted siphon pipes, without any additional backwashing device.

[0016] 2. The present invention realizes backwashing operation by opening and closing the gate and pumping water with a sludge pump, and utilizing the water level difference potential energy formed by incoming water and river water, thereby maximizing the use of existing facilities.

[0017] 3. The present invention realizes automatic regular backwashing and desilting of the inverted siphon pipe through online real-time monitoring of the water level meter and automatic control of the PLC program, avoiding manual cleaning work and hardening of silt after long-term operation that is difficult to clean.

[0018] 4. The present invention can realize the mutual switching of the backwashing pipe and the backwashed pipe between two or more inverted siphon pipes through gate opening and closing and PLC program control, thereby realizing mutual backwashing.

[0019] 5 The present invention arranges dense backwash branches between the inverted siphon pipes to achieve full coverage of the backwash area without leaving any dead corners, thereby improving the backwash effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the planar structure of the present invention; Figure 2 For the present invention Figure 1 Schematic diagram of the structural structure of section 1-1; Figure 3 For the present invention Figure 1 2-2 schematic diagram of the cross-sectional structure; Figure 4 For the present invention Figure 1 Schematic diagram of the structural construction of section 3-3; Figure 5 For the present invention Figure 1 Schematic diagram of the structural construction of section 4-4; Figure 6 Schematic diagram of the backwash branch pipe connection structure of the present invention ( Figure 5 (enlarged at A in the middle); Figure 7 The backwash branch pipe connection AA of the present invention ( Figure 6 (center) Schematic diagram of the cross-section structure.

[0021] The markings in the accompanying drawings are: water inlet pipe 1, water inlet distribution chamber 2, grille 3, overflow pipe 4, water inlet well gate 5, water inlet well 6, river water gate 7, pipeline water inlet gate 8, inverted siphon pipe 9, backwash branch pipe 10, flushing mask 101, water outlet well 11, pipeline water outlet gate 12, water outlet well gate 13, sludge pump 14, sludge pipe 141, water outlet chamber 15, water outlet pipe 16, liquid level meter 17, PLC 18. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment, a system for automatically backwashing and desilting the concave section of an inverted siphon pipe, the structure of which is referenced Figure 1-7As shown, it includes a water inlet distribution chamber 2, in which a grille 3 is arranged, the water inlet distribution chamber 2 is connected to a water inlet pipe 1 on one side of the grille 3, and the water inlet distribution chamber 2 is connected to an overflow pipe 4 at the top and two water inlet well gates 5 in the middle on the other side of the grille 3. The two water inlet well gates 5 are respectively connected to a water inlet well 6, and the water inlet well 6 is connected to a river water gate 7; the two water inlet wells 6 are respectively connected to one end of an inverted siphon pipe 9 through a pipeline inlet gate 8, and the two inverted siphon pipes 9 are separated by a plurality of intervals. The backwash branch pipe 10 is connected to the inverted siphon pipe 9 from the bottom. The other ends of the two inverted siphon pipes 9 are connected to a water outlet well 11 through a pipe outlet gate 12. The two water outlet wells 11 are connected to a water outlet chamber 15 through a water outlet gate 13. The water outlet chamber 15 is connected to a water outlet pipe 16. A sludge pump 14 is provided at the bottom of the water outlet well 11. The sludge pump 14 is connected to a sludge pipe 141. Liquid level gauges 17 are provided in the water inlet distribution chamber 2 and the water outlet well 11, respectively. The liquid level gauges 17 are electrically connected to PLC 18. Among them, the liquid level gauge 17 is preferably an ultrasonic liquid level gauge 15; and PLC 18 is preferably set as a PLC control cabinet.

[0024] A flushing mask 101 is installed at the connection between the backwash branch pipe 10 and the inverted siphon pipe 9 to prevent sludge with high density from entering the backwash branch pipe 10 and being deposited.

[0025] The flushing mask 101 is tilted toward the downstream side, so that the outflowing water during backwashing will also form an impact water flow toward the downstream side, which is conducive to flushing the sludge to the outlet well 11.

[0026] The backwash branch pipes 10 are arranged in parallel and at an equal spacing of 2.5-3.5 m, so as to achieve a reasonable density coverage of the backwashing part at the bottom of the pipe, thereby achieving a good flushing effect.

[0027] The backwash branch pipe 10 is horizontally arranged below the inverted siphon pipe 9, and its two ends are connected to the concave part at the bottom of the inverted siphon pipe 9 through elbows. The turning radius of the elbow is not less than 3 times the diameter of the backwash branch pipe 10 to achieve the best backwashing effect.

[0028] If the frequency of the river water level exceeding the top of the inverted siphon pipe 9 is high, a river water gate 7 is set on the water inlet well 6 and / or the water outlet well 11; otherwise, no river water gate 7 is set. The frequency is high enough that the river water level exceeds the top of the inverted siphon pipe 9 for more than 50% of the time. In this example, the preferred case shows that a river water gate 7 is set.

[0029] The sludge pipe 141 is connected to the outlet pipe 16 and is spaced apart from the outlet chamber 15. The sludge pipe 141 is directly connected to the outlet pipe 16 and is at a certain distance from the outlet chamber 15 to ensure that the flushed sludge is smoothly discharged into the downstream pipe.

[0030] The inverted siphon pipe 9 is arranged to be inclined downward from the water inlet well 6 to the water outlet well 11 to ensure the flow direction of water.

[0031] Preferably, the water inlet and outlet gates at both ends of the inverted siphon pipe 9 should be high-power gates with fast opening and closing speeds, and the rest can be low-power gates.

[0032] The above-mentioned automatic backwashing and desilting system for the concave section of the inverted siphon pipe can be used to perform backwashing and desilting of the concave section of the inverted siphon pipe 9 in addition to normal operation: S1: Open the water inlet gate 5, the pipeline water inlet gate 8, the pipeline water outlet gate 12 and the water outlet gate 13. After the system has been running for a period of time, when a certain amount of sediment is deposited in the inverted siphon pipe 9, the water flow section of the pipe will be reduced, the flow rate will increase and the head loss will increase. When the flow rate is large, the water level in the water inlet distribution chamber 2 will rise. The water level data monitored by the liquid level meter 17 in the water inlet distribution chamber 2 is transmitted to the PLC18 in real time. When the water level data exceeds the maximum water level setting value, the PLC18 determines to start the backwashing program; S2: After the backwashing program is started, one of the two inverted siphon pipes 9 is used as the flushed inverted siphon pipe 9, and the other is used as the flushing inverted siphon pipe 9; the PLC controls the corresponding water inlet well gate 5, water outlet well gate 13 and river water gate 7 at both ends of the flushed inverted siphon pipe 9 to close, controls the corresponding pipeline water inlet gate 8 and pipeline water outlet gate 12 at both ends of the flushing inverted siphon pipe 9 to close, starts the sludge pump 14 in the water outlet well 11 corresponding to the flushed inverted siphon pipe 9, and pumps the water in the water inlet well 6, the water outlet well 11 and the flushed inverted siphon pipe 9 to be discharged through the sludge pipe 141 and the water outlet pipe 16; S3: When the water in the flushed inverted siphon pipe 9 is pumped up and emptied to the lowest liquid level, the water level data transmitted to the PLC18 by the liquid level meter 17 is lower than the lowest water level setting value, and the PLC18 controls to stop the sludge pump 14, and opens the corresponding inlet well gate 5 and outlet well gate 13 at both ends of the flushing inverted siphon pipe 9, and uses the water in the inlet pipe 1 to fill the flushing inverted siphon pipe 9 and the corresponding inlet well 6, outlet well 11 and inlet distribution chamber 2 and outlet chamber 15 with flushing water; when the river water level is higher than the water level of the inlet pipe 1, the river water gate 7 can also be opened to use the water in the inlet pipe 1 and the river water to fill the flushing water together; S4: When the water level in the well chamber corresponding to the flushing inverted siphon pipe 9 and its two ends rises to the highest water level, the water level data transmitted to the PLC18 by the liquid level meter 17 in the corresponding outlet well 11 reaches the set water level data after being judged by the PLC18, and the PLC18 controls to first open the pipe water inlet gate 8 and the pipe water outlet gate 12 corresponding to the two ends of the flushed inverted siphon pipe 9, and then quickly open the pipe water inlet gate 8 and the pipe water outlet gate 12 corresponding to the two ends of the flushing inverted siphon pipe 9, and the flushing water stored in the well chamber corresponding to the two ends of the flushing inverted siphon pipe 9 enters the flushing inverted siphon pipe 9 and then hydraulically backwashes the concave part at the bottom of the flushed inverted siphon pipe 9 through the backwashing branch pipe 10; S5: When the hydraulic backwashing continues until the water levels in the corresponding well chambers at both ends of the two inverted siphon pipes 9 reach equilibrium, the water level data transmitted to the PLC 18 by the level gauges 17 in the two outlet wells 11 are consistent, and the backwashing program is ended through the control of the PLC 18, and the corresponding pipe water inlet gate 8, pipe water outlet gate 12 and river water gate 7 at both ends of the backwashing inverted siphon pipe 9 are closed, and the corresponding sludge pump 14 is started to pump up all the sludge in the flushed inverted siphon pipe 9 and discharge it through the sludge pipe 141 and the outlet pipe 16; S6: After the sludge pump 14 has completed pumping up the sludge in the flushed inverted siphon pipe 9, the corresponding inlet well gate 5 and outlet well gate 13 at both ends of the flushed inverted siphon pipe 9 are opened, and the corresponding pipe inlet gate 8 and pipe outlet gate 12 at both ends of the backwashing inverted siphon pipe 9 are opened to restore the system to normal operation.

[0033] In actual practice, the number of flushing times is set according to the actual flushing effect, and steps S1-S6 are repeated for multiple flushing to ensure the flushing effect.

[0034] Obviously, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. A system for automatically backwashing and desilting the concave section of an inverted siphon pipe, characterized in that: The invention comprises a water inlet distribution chamber (2), wherein a grille (3) is arranged in the water inlet distribution chamber (2), the water inlet distribution chamber (2) is connected to a water inlet pipe (1) on one side of the grille (3), and the water inlet distribution chamber (2) is connected to an overflow pipe (4) at the top and two water inlet well gates (5) in the middle on the other side of the grille (3), the two water inlet well gates (5) are respectively connected to a water inlet well (6), and the water inlet well (6) is connected to a river water gate (7); the two water inlet wells (6) are respectively connected to one end of an inverted siphon pipe (9) through a pipe inlet gate (8), and the two inverted siphon pipes (9) are connected by a plurality of spacers arranged between them. The backwash branch pipe (10) is connected to the inverted siphon pipe (9) from the bottom. The other ends of the two inverted siphon pipes (9) are respectively connected to a water outlet well (11) through a pipe water outlet gate (12). The two water outlet wells (11) are respectively connected to a water outlet chamber (15) through a water outlet gate (13). The water outlet chamber (15) is connected to the water outlet pipe (16). A sludge pump (14) is provided at the bottom of the water outlet well (11). The sludge pump (14) is connected to the sludge pipe (141). Liquid level gauges (17) are respectively provided in the water inlet distribution chamber (2) and the water outlet well (11). The liquid level gauges (17) are electrically connected to the PLC (18).

2. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: A flushing mask (101) is installed at the connection between the backwash branch pipe (10) and the inverted siphon pipe (9).

3. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 2 is characterized in that: The flushing mask (101) is arranged to be inclined toward the downstream side.

4. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: The backwash branch pipes (10) are arranged in parallel and at equal intervals with a spacing of 2.5-3.5 m.

5. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: The backwash branch pipe (10) is arranged below the inverted siphon pipe (9), and its two ends are connected to the concave portion at the bottom of the inverted siphon pipe (9) via elbows, wherein the turning radius of the elbow is not less than 3 times the pipe diameter of the backwash branch pipe (10).

6. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: If the frequency of the river water level exceeding the top of the inverted siphon pipe (9) is high, a river water gate (7) is provided on the water inlet well (6) and / or the water outlet well (11); otherwise, no river water gate (7) is provided.

7. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: The sludge pipeline (141) is connected to the water outlet pipe (16), and the sludge pipeline (141) is spaced apart from the water outlet chamber (15).

8. The automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 1 is characterized in that: The inverted siphon pipe (9) is arranged to be inclined downward from the water inlet well (6) to the water outlet well (11).

9. A method for using the automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to any one of claims 1 to 8, characterized in that: The method comprises the following steps of backwashing the concave section of the inverted siphon pipe (9): S1: Open the water inlet well gate (5), the pipeline water inlet gate (8), the pipeline water outlet gate (12) and the water outlet well gate (13). After the system has been running for a period of time, when sediment accumulates in the inverted siphon pipe (9), the water flow section of the pipe will be reduced, the flow rate will increase, and the head loss will increase. When the flow rate is large, the water level in the water inlet distribution chamber (2) will rise. The water level data monitored by the liquid level meter (17) in the water inlet distribution chamber (2) is transmitted to the PLC (18) in real time. When the water level data exceeds the maximum water level setting value, the PLC (18) determines to start the backwashing program; S2: After the backwashing procedure is started, one of the two inverted siphon pipes (9) is used as the flushed inverted siphon pipe (9), and the other is used as the flushing inverted siphon pipe (9); the PLC controls the corresponding water inlet well gate (5), water outlet well gate (13) and river water gate (7) at both ends of the flushed inverted siphon pipe (9) to be closed, controls the corresponding pipe inlet gate (8) and pipe outlet gate (12) at both ends of the flushing inverted siphon pipe (9) to be closed, and starts the sludge pump (14) in the outlet well (11) corresponding to the flushed inverted siphon pipe (9) to pump up the water in the inlet well (6), the outlet well (11) and the flushed inverted siphon pipe (9) and discharge it through the sludge pipe (141); S3: When the water in the flushed inverted siphon pipe (9) is pumped up and emptied to the lowest liquid level, the water level data transmitted by the liquid level meter (17) to the PLC (18) is lower than the lowest water level setting value, and the PLC (18) controls the sludge pump (14) to stop, and opens the corresponding inlet well gates (5) and outlet well gates (13) at both ends of the flushing inverted siphon pipe (9), and uses the water in the inlet pipe (1) to fill the flushing inverted siphon pipe (9) and the corresponding inlet wells (6), outlet wells (11) and inlet distribution chambers (2) and outlet chambers (15) with flushing water; when the river water gate (7) is set, the PLC (18) also opens the corresponding river water gate (7) to use river water to assist in filling the flushing water; S4: When the water level in the flushing inverted siphon pipe (9) and the well chambers corresponding to both ends thereof rises to the highest water level, the water level data transmitted to the PLC (18) by the liquid level meter (17) in the corresponding outlet well (11) reaches the set water level data, and the PLC (18) controls to first open the pipe water inlet gate (8) and the pipe water outlet gate (12) corresponding to both ends of the flushed inverted siphon pipe (9), and then quickly open the pipe water inlet gate (8) and the pipe water outlet gate (12) corresponding to both ends of the flushing inverted siphon pipe (9), and the flushing water stored in the well chambers corresponding to both ends of the flushing inverted siphon pipe (9) enters the flushing inverted siphon pipe (9) and then passes through the backwashing branch pipe (10) to hydraulically backwash the concave part at the bottom of the flushed inverted siphon pipe (9); S5: When the hydraulic backwashing continues until the water levels in the corresponding well chambers at both ends of the two inverted siphon pipes 9 reach equilibrium, the water level data transmitted from the level gauges (17) in the two outlet wells (11) to the PLC (18) are consistent, and the backwashing program is terminated through the control of the PLC (18), and the corresponding pipe water inlet gates (8), pipe water outlet gates (12) and river water gates (7) at both ends of the backwashing inverted siphon pipe (9) are closed, and the corresponding sludge pumps (14) are started to pump up all the sludge in the flushed inverted siphon pipe (9) and discharge it through the sludge pipe (141); S6: After the sludge pump (14) has completed pumping up the sludge in the flushed inverted siphon pipe (9), the corresponding inlet well gate (5) and outlet well gate (13) at both ends of the flushed inverted siphon pipe (9) are opened, and the corresponding pipe inlet gate (8) and pipe outlet gate (12) at both ends of the backwashing inverted siphon pipe (9) are opened, and the system is restored to normal operation.

10. The method for using the automatic backwashing and desilting system for the concave section of an inverted siphon pipe according to claim 9, characterized in that: It also includes setting the number of flushing times according to the actual flushing effect, and repeating steps S1-S6 to perform multiple flushing.

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