Aerated grit chamber for optimizing slag scraping effect and control method thereof

Abstract

The invention relates to an aerated grit chamber capable of optimizing a slag scraping effect and a control method of the aerated grit chamber. The device comprises a grit chamber, the water inlet well and the water outlet well are respectively arranged at the upstream and the downstream of the grit chamber; the slag hopper is arranged on the side wall of the grit chamber, the slag hopper is communicated with a slag outlet pipe, the slag hopper is provided with a slag hopper inlet, and an inlet covering surface is arranged on the slag hopper inlet; the sand suction machine comprises a moving platform which reciprocates along the top of the grit chamber, and a sand suction pump and a slag scraping device which are respectively mounted on the moving platform, and the slag scraping device comprises a slag scraping plate and a driving device for driving the slag scraping plate to lift; the aeration pipe is positioned in the middle of the grit chamber and is used for introducing air into the grit chamber to form circular flow; the ultrasonic liquid level meter synchronously moves along with the slag scraping plate and is used for detecting the real-time liquid level height in the grit chamber and outputting a liquid level signal; the height of the slag scraping plate is adjusted according to the liquid level signal, so that the bottom of the slag scraping plate is always lower than the real-time liquid level height. The slag scraping device greatly improves the slag scraping effect.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to an aerated grit chamber with optimized sludge scraping effect and its control method. Background Technology

[0002] Wastewater treatment plant aerated grit chambers typically use aeration pipes to create a swirling effect along the cross-section of the wastewater flowing into the chamber. This swirling action causes heavier sand particles to fall to the bottom and be discharged by a grit pump. Lighter scum tends to float on the surface and is therefore removed by a scraper mounted on a grit suction machine. Normally, the scraper is fixed to the suction machine platform at a constant height, only activating to remove scum when the liquid level is just above the bottom of the scraper. While the scraper is typically installed at the designed liquid level, in actual operation, the liquid level in the grit chamber fluctuates significantly with the water volume. The fixed scraper cannot adapt to these fluctuations, resulting in poor scraping efficiency, ineffective removal of scum from the surface, poor appearance of the chamber, and negatively impacting wastewater treatment effectiveness. Summary of the Invention

[0003] Therefore, the present invention provides an aerated grit chamber and its control method for optimizing sludge scraping effect. By setting the linkage between the liquid level signal provided by the ultrasonic level gauge and the height of the sludge scraper, the sludge scraper can be automatically adjusted with the water level, which greatly improves the sludge scraping effect.

[0004] To solve the above-mentioned technical problems, the present invention provides an aerated grit chamber with optimized sludge scraping effect, comprising: Grit chamber; The inlet well and outlet well are respectively located upstream and downstream of the sedimentation tank; A slag hopper is provided on the side wall of the sedimentation tank. The slag hopper is connected to a slag discharge pipe. The slag hopper is provided with a slag hopper inlet and an inlet cover is provided on the slag hopper inlet. The sand suction machine includes a mobile platform that reciprocates along the top of the sedimentation tank, and a sand suction pump and a slag scraping device respectively installed on the mobile platform. The slag scraping device includes a slag scraping plate and a drive device for driving the slag scraping plate to rise and fall. An aeration pipe, located in the middle of the settling tank, is used to introduce air into the settling tank to form a circulation. Heavier sand in the settling tank settles to the bottom of the settling tank and is sucked out by the sand suction pump. Lighter scum floats to the surface of the settling tank under the action of air, is scraped into the scum hopper by the scum scraping device, and is discharged out through the scum outlet pipe. An ultrasonic level gauge moves synchronously with the scraper plate to detect the real-time liquid level in the sedimentation tank and output a liquid level signal. The control system is configured to receive the liquid level signal and adjust the height of the scraper plate according to the liquid level signal during the reciprocating motion of the scraper driven by the sand suction machine, so that the bottom of the scraper plate is always lower than the real-time liquid level height.

[0005] In one embodiment of the present invention, a guide rod is connected between the driving device and the scraper plate. A guide rod slot is provided at the top of the sedimentation tank at the corresponding position of the guide rod, extending along the length of the tank body. The guide rod can be guided to move along the guide rod slot to realize the reciprocating movement of the scraper device.

[0006] In one embodiment of the present invention, the slag hopper is a rectangular concrete structure connected to the wall of the settling tank, and the slag discharge pipe is connected to the bottom of the slag hopper for transporting the scum scraped into the slag hopper to the outside of the settling tank.

[0007] In one embodiment of the present invention, the slag hopper inlet is inclined at 45° along the horizontal plane of the sedimentation tank.

[0008] In one embodiment of the present invention, the inlet cover is fixed to the pool wall of the slag hopper inlet using expansion bolts.

[0009] In one embodiment of the present invention, the driving device is an electric gate hoist, which is equipped with a stepless adjustable motor and can linearly adjust the height of the scraper plate according to the liquid level signal.

[0010] In one embodiment of the present invention, the slag scraper is made of plastic-lined steel plate, the plastic-lined steel plate is L-shaped plate, and the bottom of the short side of the L-shaped plate is provided with a plastic lining layer, the plastic lining layer being made of rubber.

[0011] In one embodiment of the present invention, the slag scraping device further includes a ribbed steel plate, the plastic-lined steel plate and the ribbed steel plate are detachably connected by connecting screws, and the ultrasonic level gauge is connected to the ribbed steel plate.

[0012] In one embodiment of the present invention, the lowest point of the scraper is level with the bottom elevation of the inlet cover.

[0013] This invention also provides a control method for an aerated grit chamber with optimized sludge scraping effect. The control method, utilizing the aforementioned aerated grit chamber with optimized sludge scraping effect, includes: Wastewater flows into the grit chamber from the inlet well, where fine sand is separated and scum floats to the surface of the grit chamber under the aeration of the aeration pipes. Wastewater then flows into the outlet well through the overflow hole of the grit chamber and is discharged to the next treatment structure. The first real-time liquid level height in the sedimentation tank is obtained by an ultrasonic level gauge. The lifting position of the scraper is adjusted by the drive device, and the bottom elevation of the scraper is controlled to be a predetermined distance lower than the first real-time liquid level, so that the bottom of the scraper is always kept lower than the first real-time liquid level. Control the sand suction machine to move along the length of the sedimentation tank at a preset walking speed, and drive the scum scraper to scrape and push the scum from the effluent well side to the scum hopper side. When the slag scraper moves to the vicinity of the inlet cover, the second real-time liquid level height in the sedimentation tank is obtained by the ultrasonic level gauge; When the difference between the first real-time liquid level height and the second real-time liquid level height is greater than the preset height difference threshold, the rising control amount of the drive device is adjusted based on the preset walking speed so that the rising speed of the slag scraper is equal to the preset walking speed. The slag is guided and scraped into the slag hopper by the slag scraper and then discharged out of the sedimentation tank through the slag outlet pipe. The third real-time liquid level height in the sedimentation tank is obtained by an ultrasonic level gauge. In response to the third real-time liquid level height reaching the highest point of the slag hopper inlet, the sand suction machine is controlled to move in the opposite direction at the preset walking speed, and the slag scraping device is controlled to descend and reset at the same speed as the preset walking speed, so that the bottom elevation of the slag scraping plate is restored to a predetermined distance lower than the first real-time liquid level height.

[0014] The technical solution of the present invention has the following advantages compared with the prior art: This invention discloses an aerated grit chamber and its control method for optimizing scum scraping. After wastewater enters the grit chamber, air is introduced into the water through aeration pipes installed within the chamber, creating a stable swirling flow. Under this swirling effect, denser sand particles settle downwards and are discharged from the chamber by a sand suction pump, while less dense scum floats and accumulates on the surface. By controlling the scum scraping device, the bottom of its scraper plate is always kept 2-3 cm below the real-time water level. During the reciprocating motion of the sand suction pump, the scraping device operates accordingly, continuously scraping and pushing the scum from the surface into the scum hopper, which is then discharged from the chamber through the scum outlet pipe.

[0015] This aerated grit chamber and its control method effectively avoid the problem of the scraper plate being unable to remove scum due to fluctuations in the liquid level in the chamber, which would cause the scum to rise above the water level. At the same time, it prevents scum from accumulating to an excessively thick state and then being forcibly scraped off, which could lead to abnormal stress on the scraper plate or even damage. This significantly improves the stability and reliability of scum removal in the aerated grit chamber, allowing scum on the surface of the chamber to be continuously and evenly scraped off, reducing scum accumulation and optimizing the overall operating effect. Attached Figure Description

[0016] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of the aerated grit chamber with optimized sludge scraping effect according to the present invention.

[0018] Figure 2 This is a side view of the aerated grit chamber structure for optimizing sludge scraping effect according to the present invention.

[0019] Explanation of reference numerals in the instruction manual: 1. Inlet well; 2. Sedimentation tank; 3. Sand suction machine; 4. Outlet well; 5. Sand suction pump; 6. Drive unit; 7. Guide rod; 8. Ribbed steel plate; 9. Slag scraper; 10. Connecting screw; 11. Slag hopper; 12. Slag discharge pipe; 13. Slag hopper inlet; 14. Inlet cover; 15. Aeration pipe; 16. Ultrasonic level gauge; 31. Moving platform; 32. Slag scraper; 71. Guide rod slot. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0021] In this invention, when directions (up, down, left, right, front, and back) are described, it is only for the purpose of describing the technical solution of this invention, and does not indicate or imply that the technical features referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0022] In this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number. In the description of this invention, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0023] In this invention, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; a fixed connection, a detachable connection, or an integrally formed connection; a mechanical connection, an electrical connection, or a connection capable of mutual communication; or the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this invention based on the specific content of the technical solution.

[0024] Reference Figure 1 , Figure 2As shown, an aerated grit chamber 2 for optimizing sludge scraping effect according to the present invention includes: Sedimentation tank 2; Inlet well 1 and outlet well 4 are respectively located upstream and downstream of the sedimentation tank 2; Slag hopper 11 is provided on the side wall of the sedimentation tank 2. The slag hopper 11 is connected to a slag discharge pipe 12. The slag hopper 11 is provided with a slag hopper inlet 13. An inlet cover 14 is provided on the slag hopper inlet 13. The sand suction machine 3 includes a mobile platform 31 that reciprocates along the top of the sedimentation tank 2, a sand suction pump 5 and a slag scraping device 32 respectively installed on the mobile platform 31, and the slag scraping device 32 includes a slag scraping plate 9 and a driving device 6 that drives the slag scraping plate 9 to rise and fall. The aeration pipe 15 is located in the middle of the sedimentation tank 2 and is used to introduce air into the sedimentation tank 2 to form a circulation. The heavier sand in the sedimentation tank 2 settles to the bottom of the sedimentation tank 2 and is sucked out by the sand suction pump 5. The lighter scum floats to the surface of the sedimentation tank 2 under the action of air and is scraped into the scum hopper 11 by the scum scraping device 32 and discharged through the scum outlet pipe 12. The ultrasonic level gauge 16 moves synchronously with the scraper 9 and is used to detect the real-time liquid level in the sedimentation tank 2 and output a liquid level signal. The control system (such as a PLC) is configured to receive the liquid level signal and adjust the height of the scraper plate 9 according to the liquid level signal during the reciprocating motion of the sand suction machine 3 and the scraper device 32. This ensures that the bottom of the scraper plate 9 is always lower than the real-time liquid level (e.g., 2cm-3cm) and that the bottom of the scraper plate 9 is always kept within a small submersion range below the liquid surface. This allows for continuous and effective pushing of the scum on the pool surface, preventing the scraper plate 9 from being suspended and unable to scrape the scum due to liquid level fluctuations, thus optimizing the scum removal effect of the aerated grit chamber 2.

[0025] In one embodiment, a guide rod 7 is connected between the drive device 6 and the scraper plate 9. The top of the sedimentation tank 2 has a guide rod slot 71 extending along the length of the tank body at the corresponding position of the guide rod 7. The guide rod 7 can be guided to move along the guide rod slot 71 to realize the reciprocating movement of the scraper device 32.

[0026] In one embodiment, the slag hopper 11 is a rectangular concrete structure connected to the wall of the sedimentation tank 2, and the slag discharge pipe 12 is connected to the bottom of the slag hopper 11 to transport the scum scraped into the slag hopper 11 to the outside of the sedimentation tank 2.

[0027] In one embodiment, the slag hopper inlet 13 is inclined at 45° along the horizontal plane of the sedimentation tank 2, so that the scum can more easily cross the boundary and enter the slag hopper 11 under the action of scraping force, reducing the accumulation at the slag hopper inlet 13.

[0028] In one embodiment, the inlet cover 14 is fixed to the pool wall of the slag hopper inlet 13 using expansion bolts. It should be noted that the inlet cover 14 (along a 45° angle) extends onto the slag hopper inlet 13 and is a cover panel fixed at the slag hopper inlet 13, used to cover the top of the slag hopper inlet 13 and form a guide interface for scum introduction. The scum pushed by the scraper 9 slides along the inlet cover 14 and enters the slag hopper 11 along the boundary of the inlet cover 14, reducing scum accumulation along the slag hopper inlet 13.

[0029] In one embodiment, the driving device 6 is an electric gate hoist, which is equipped with a stepless adjustable motor that can linearly adjust the height of the scraper plate 9 according to the liquid level signal.

[0030] In one embodiment, the scraper plate 9 is made of plastic-lined steel plate, which is an L-shaped plate, and the bottom of the short side of the L-shaped plate is provided with a plastic lining layer, which is made of rubber.

[0031] In one embodiment, the slag scraping device 32 further includes a reinforcing steel plate 8. The plastic-lined steel plate and the reinforcing steel plate 8 are detachably connected by connecting screws 10, and the ultrasonic level gauge 16 is connected to the reinforcing steel plate 8. The bottom of the plastic-lined steel plate is lined with rubber material to prevent sharp friction noise during slag scraping. To facilitate system replacement and maintenance, the plastic-lined steel plate is connected to the bottom of the reinforcing steel plate 8 with connecting bolts, allowing for easy replacement if the plastic-lined steel plate bends due to system debugging or electric hoist malfunction.

[0032] In one embodiment, the lowest point of the scraper 9 is level with the bottom elevation of the inlet cover 14.

[0033] This embodiment also provides a control method for an aerated grit chamber 2 with optimized sludge scraping effect. The control method, utilizing the aerated grit chamber 2 with optimized sludge scraping effect, includes: S1. Sewage flows into grit chamber 2 from inlet well 1, where fine sand is separated and scum floats to the surface of grit chamber 2 under the aeration of aeration pipe 15. Sewage flows into outlet well 4 through the overflow hole of grit chamber 2 and is discharged to the next treatment structure. S2. Obtain the first real-time liquid level height h1 in the sedimentation tank 2 using the ultrasonic level gauge 16; S3. Adjust the lifting position of the scraper plate 9 by the drive device 6, and control the bottom elevation of the scraper plate 9 to be 2cm-3cm lower than the first real-time liquid level height h1 by a predetermined distance, so that the bottom of the scraper plate 9 is always kept lower than the first real-time liquid level height h1. S4. Control the sand suction machine 3 to move along the length of the sedimentation tank 2 at a preset walking speed v, and drive the scum scraper 32 to scrape and push the scum from the side of the outlet well 4 to the side of the scum hopper 11. Figure 1 (From the right side of the pool to the left side of the pool) S5. When the slag scraping device 32 moves to the vicinity of the inlet cover 14, the second real-time liquid level height h2 in the sedimentation tank 2 is obtained by the ultrasonic level gauge 16. S6. When the slag scraping device 32 approaches the vicinity of the inlet cover 14, the liquid level reading of the ultrasonic level gauge 16 will suddenly decrease due to the influence of the inlet cover 14. In response to the difference between the first real-time liquid level height h1 and the second real-time liquid level height h2 being greater than the preset height difference threshold, the upward control amount of the drive device 6 is adjusted based on the preset walking speed v, so that the upward speed of the slag scraping device 32 is equal to the preset walking speed. The slag is guided by the scraper plate 9 to adhere to the inlet cover 14 and scraped into the slag hopper 11, and discharged out of the sedimentation tank 2 through the slag discharge pipe 12. S7. The third real-time liquid level height h3 in the sedimentation tank 2 is obtained by the ultrasonic level gauge 16. In response to the third real-time liquid level height h3 reaching the elevation H of the highest point of the slag hopper inlet 13, the sand suction machine 3 is controlled to move in the opposite direction at the preset walking speed, and the slag scraping device 32 is controlled to descend and reset at the same speed as the preset walking speed v, so that the bottom elevation of the slag scraping plate 9 is restored to a predetermined distance lower than the first real-time liquid level height h1. S8. Repeat steps S2 to S7 to maintain stable slag scraping under conditions of water level fluctuation and surface disturbance, and continuously guide the slag into the slag hopper 11 for discharge.

[0034] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An aerated grit chamber (2) with optimized sludge scraping effect, characterized in that, include: Sedimentation tank (2); The inlet well (1) and the outlet well (4) are respectively located upstream and downstream of the sedimentation tank (2); A slag hopper (11) is provided on the side wall of the sedimentation tank (2). The slag hopper (11) is connected to a slag outlet pipe (12). The slag hopper (11) is provided with a slag hopper inlet (13). An inlet cover (14) is provided on the slag hopper inlet (13). The sand suction machine (3) includes a mobile platform (31) that moves back and forth along the top of the sedimentation tank (2) and a sand suction pump (5) and a slag scraping device (32) respectively installed on the mobile platform (31). The slag scraping device (32) includes a slag scraping plate (9) and a driving device (6) that drives the slag scraping plate (9) to rise and fall. The aeration pipe (15) is located in the middle of the sedimentation tank (2) and is used to introduce air into the sedimentation tank (2) to form a circulation. The heavier sand in the sedimentation tank (2) is deposited to the bottom of the sedimentation tank (2) and sucked out by the sand suction pump (5). The lighter scum floats to the surface of the sedimentation tank (2) under the action of air and is scraped into the scum hopper (11) by the scum scraping device (32) and discharged outside through the scum outlet pipe (12). An ultrasonic level gauge (16) moves synchronously with the scraper (9) to detect the real-time liquid level in the sedimentation tank (2) and output a liquid level signal. The control system is configured to receive the liquid level signal and adjust the height of the scraper plate (9) according to the liquid level signal during the reciprocating motion of the sand suction machine (3) driving the scraper device (32), so that the bottom of the scraper plate (9) is always lower than the real-time liquid level height.

2. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, A guide rod (7) is connected between the drive device (6) and the scraper plate (9). The top of the sedimentation tank (2) has a guide rod slot (71) extending along the length of the tank body at the corresponding position of the guide rod (7). The guide rod (7) can be guided to move along the guide rod slot (71) to realize the reciprocating movement of the scraper device (32).

3. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The slag hopper (11) is a rectangular concrete structure connected to the wall of the sedimentation tank (2). The slag discharge pipe (12) is connected to the bottom of the slag hopper (11) and is used to transport the slag scraped into the slag hopper (11) to the outside of the sedimentation tank (2).

4. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The slag hopper inlet (13) is set at an angle of 45° along the horizontal plane of the sedimentation tank (2).

5. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The inlet cover (14) is fixed to the pool wall of the slag hopper inlet (13) by expansion bolts.

6. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The drive device (6) is an electric gate opener, which is equipped with a stepless adjustable motor and can linearly adjust the height of the scraper plate (9) according to the liquid level signal.

7. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The scraper plate (9) is made of plastic-lined steel plate. The plastic-lined steel plate is an L-shaped plate, and the bottom of the short side of the L-shaped plate is provided with a plastic lining layer. The plastic lining layer is made of rubber.

8. The aerated grit chamber (2) with optimized sludge scraping effect according to claim 7, characterized in that, The slag scraping device (32) also includes a ribbed steel plate (8), the plastic-lined steel plate and the ribbed steel plate (8) are detachably connected by connecting screws (10), and the ultrasonic level gauge (16) is connected to the ribbed steel plate (8).

9. An aerated grit chamber (2) with optimized sludge scraping effect according to claim 1, characterized in that, The lowest point of the scraper (9) is level with the bottom elevation of the inlet cover (14).

10. A control method for an aerated grit chamber (2) to optimize sludge scraping effect, characterized in that, The control method for the aerated grit chamber (2) with optimized sludge scraping effect according to any one of claims 1-9 includes: Wastewater flows into the grit chamber (2) through the inlet well (1), where fine sand is separated. The scum floats to the surface of the grit chamber (2) under the aeration of the aeration pipe (15). Wastewater flows into the outlet well (4) through the overflow hole of the grit chamber (2) and is discharged to the next treatment structure. The first real-time liquid level height in the sedimentation tank (2) is obtained by ultrasonic level gauge (16); The lifting position of the scraper (9) is adjusted by the drive device (6), and the bottom elevation of the scraper (9) is controlled to be a predetermined distance lower than the first real-time liquid level height, so that the bottom of the scraper (9) is always kept lower than the first real-time liquid level height. Control the sand suction machine (3) to move along the length of the sedimentation tank (2) at a preset walking speed, and drive the scum scraper (32) to scrape and push the scum from the side of the outlet well (4) to the side of the scum hopper (11); When the slag scraper (32) moves to the vicinity of the inlet cover (14), the second real-time liquid level height in the sedimentation tank (2) is obtained by the ultrasonic level gauge (16); When the difference between the first real-time liquid level height and the second real-time liquid level height is greater than the preset height difference threshold, the rising control amount of the drive device (6) is adjusted based on the preset walking speed so that the rising speed of the scraper device (32) is equal to the preset walking speed. The scum is guided and scraped into the scum hopper (11) by the scraper plate (9) and then discharged out of the sedimentation tank (2) through the scum outlet pipe (12). The third real-time liquid level height in the sedimentation tank (2) is obtained by the ultrasonic level gauge (16). In response to the third real-time liquid level height reaching the highest elevation of the slag hopper inlet (13), the sand suction machine (3) is controlled to move in the opposite direction at the preset walking speed, and the slag scraping device (32) is controlled to descend and reset at the same speed as the preset walking speed, so that the bottom elevation of the slag scraper (9) is restored to a predetermined distance lower than the first real-time liquid level height.

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