CN119425263B - Dust filtration system and filtration method for bridge engineering construction - Google Patents

Abstract

The present invention discloses a dust filtration system and filtration method for bridge engineering construction, including an exhaust device, an aeration dust removal device and a wastewater sedimentation device, wherein the wastewater sedimentation device includes a plurality of sedimentation units, the aeration dust removal device is connected to a drainage channel, the drainage channel is connected to the plurality of sedimentation units, and a buoyancy opening and closing mechanism is provided in the sedimentation unit, which can close the drainage channel where the sedimentation unit is located after wastewater is loaded into the sedimentation unit and open the water inlet of the adjacent sedimentation unit at the same time; a plurality of water outlets are also provided on both sides of the sedimentation unit, and a float normally closed switch is provided at each water outlet, which is used to open the water outlet when the liquid level drops; the water outlets on both sides of the sedimentation unit are arranged alternately in the vertical direction. The present invention solves the problem of slow wastewater filtration in traditional sedimentation-type, thereby improving the processing efficiency of dust filtration.

Description

Dust filtration system and filtration method for bridge engineering construction

Technical Field

The present invention relates to the technical field of dust removal and purification in engineering construction, and in particular to a dust filtering system and a filtering method for bridge engineering construction.

Background Art

During the construction of bridges, large amounts of dust will be generated in many specific construction processes, such as local mountain blasting, bridge deck cutting, steel bar welding, etc. At present, spray treatment is generally used to treat the dust generated by construction, so as to wet and settle the dust. However, this spray treatment method is generally only used for large-scale construction. For occasions with high concentration and high dust content, the dust removal effect is poor. For occasions with high concentration and high dust content, exhaust fans are generally used to extract air and pass it into a pool for water filtration. Water can remove dust from the air, and the air coming out is relatively clean. However, because the filtered water is rich in dust, it needs to be precipitated. The sludge after precipitation is collected and processed, and the clean water is recycled. However, the sedimentation treatment speed is slow. During the construction of bridge projects, it is difficult to build a large sedimentation tank for sedimentation and separation treatment. A small sedimentation tank is difficult to meet the construction needs of large amounts of dust.

Summary of the invention

Aiming at the problem of low sedimentation efficiency of dust filtration in the existing bridge construction process, the present invention provides a dust filtration system and a filtration method for bridge engineering construction, which can effectively improve the sedimentation efficiency and meet the application of large dust construction occasions.

The present invention is achieved through the following technical solutions:

A dust filtration system for bridge engineering construction, comprising an exhaust device, an aeration dust removal device and a wastewater sedimentation device, wherein the exhaust device is used to suck dust generated during the bridge engineering construction process, the aeration dust removal device is connected to the exhaust device, and the wind extracted by the exhaust device can be passed into the aeration dust removal device for aeration purification, the wastewater sedimentation device is connected to the aeration dust removal device, and is used to pass the dust-absorbed wastewater into the wastewater sedimentation device for sedimentation and separation, the wastewater sedimentation device has a clean water outlet and a sludge outlet, and the clean water outlet is connected to the aeration dust removal device so that the clean water after sedimentation is recycled;

The wastewater sedimentation device includes a plurality of sedimentation units. The aeration and dust removal device is connected to a drainage channel, which is connected to the plurality of sedimentation units. A buoyancy opening and closing mechanism is provided in the sedimentation unit, which can close the drainage channel where the sedimentation unit is located and open the water inlet of the adjacent sedimentation unit after wastewater is loaded into the sedimentation unit; a plurality of water outlets are also provided on both sides of the sedimentation unit, and a float normally closed switch is provided at each water outlet, which is used to open the water outlet when the liquid level drops; the water outlets on both sides of the sedimentation unit are arranged alternately in sequence in the vertical direction.

Optionally, the buoyancy opening and closing mechanism includes a buoyancy component, a first guide component, a first gate plate, a second guide component and a second gate plate. The buoyancy component is configured in the sedimentation unit and is guided by the first guide component; the first gate plate is connected to the buoyancy component by a first connecting rod, and the first gate plate is guided by the second guide component. The buoyancy component can drive the first gate plate to move on the second guide component through the first connecting rod, thereby opening or closing the drainage channel where the sedimentation unit is located; the second gate plate is used to close the water inlet of the sedimentation unit. The first gate plate is also connected to the second gate plate of the adjacent sedimentation unit through the second connecting rod. When the first gate plate closes the drainage channel where the sedimentation unit is located, it can drive the second gate plate of the adjacent sedimentation unit to move through the second connecting rod, thereby opening the water inlet of the adjacent sedimentation unit.

Optionally, the float normally closed switch includes a ball cage structure arranged in the vertical direction, a float is arranged in the ball cage structure, a sealing ball is arranged in the water outlet, and the float and the sealing ball are connected by a connecting line; the highest floating position of the buoyancy component is vertically lower than the floating position of the float of the float normally closed switch located at the top; in the vertical direction, the lowest floating position of the float of the float normally closed switch is lower than the highest floating position of the float of the next float normally closed switch.

Optionally, the water outlet at the lowest end is connected to a sludge tank, and the other water outlets are connected to an aeration and dust removal device.

Optionally, the bottom of the sedimentation unit adopts an inclined structure inclined toward a water outlet connected to the sludge tank, and the water inlet of the sedimentation unit is arranged on the opposite side of the water outlet connected to the sludge tank.

Optionally, the drainage channel also includes a drainage main pipe and a drainage branch pipe, the drainage main pipe is connected to all the sedimentation units in sequence, one end of the drainage branch pipe is connected to the drainage main pipe, and the other end is provided with a plurality of connecting parts, which are respectively connected to the drainage main pipes at a certain distance through the connecting parts, and each connecting part is provided with a solenoid valve.

Optionally, a clean water temporary storage device is provided between the wastewater sedimentation device and the aeration dust removal device.

Optionally, the aeration and dust removal device is also connected to a clean water supply device.

A filtering method based on the above-mentioned dust filtering system for bridge engineering construction comprises the following steps:

The dust is extracted through the exhaust device and then passed into the aeration dust removal device. The dust is purified and filtered by the water in the aeration dust removal device. The wastewater generated in the aeration dust removal device is passed into the wastewater sedimentation device for separation. The separated clean water is then returned to the aeration dust removal device for use, and the sludge is centrally treated;

Among them, the separation of the wastewater sedimentation device relies on the drainage channel to enter the sedimentation unit located at the end of the drainage channel. After it is full, the corresponding drainage channel is closed by the buoyancy opening and closing mechanism, and the water inlet of an adjacent sedimentation unit is opened at the same time to allow the next sedimentation unit to enter water, and so on, the water entry of each sedimentation unit is completed in sequence; after each sedimentation unit is filled with water, sedimentation begins, and the topmost float normally closed switch is opened first to release clean water, which is then collected and returned to the aeration dust removal device for use. When the water level drops to the position of the next float normally closed switch, the float normally closed switch is activated to continue to release clean water, and so on, from top to bottom, the clean water after sedimentation separation is released.

The technical solution of the present invention has at least the following beneficial effects:

The dust filtration system for bridge engineering construction of the present invention can realize separate sedimentation without affecting each other by dividing the wastewater sedimentation device into a plurality of sedimentation units. Compared with the traditional technology which requires a large-volume sedimentation tank for a long time, resulting in the problems of large floor space, slow sedimentation separation and inability to replenish water in time; the water inlet of each sedimentation unit is isolated by a buoyancy opening and closing mechanism, and drainage is achieved during the sedimentation process by means of alternately arranged float normally closed switches, ensuring that clean water separation can be achieved during the sedimentation process, even if water for dust filtration is replenished, thereby improving the dust filtration effect.

The dust filtering method for bridge engineering construction of the present invention relies on an aeration dust removal device to achieve dust filtration, and then continuously passes wastewater into a sedimentation device to achieve timely sedimentation and separation. The clean water after sedimentation and separation can be replenished to the aeration dust removal device in time, effectively saving water.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a dust filtration system for bridge engineering construction according to the present invention;

FIG2 is a schematic top view of the structure of the wastewater sedimentation device of the present invention;

FIG3 is a diagram showing the water inlet state of the terminal sedimentation unit of the wastewater sedimentation device of the present invention;

FIG4 is a diagram showing the water inflow state of the second sedimentation unit from the end of the wastewater sedimentation device of the present invention;

FIG5 is a schematic side view of the structure of the wastewater sedimentation device of the present invention;

FIG. 6 is an enlarged view of part a of FIG. 5 .

Icons: 100-exhaust device, 200-aeration and dust removal device, 300-wastewater sedimentation device, 400-clean water temporary storage device, 500-clean water supply device, 310-sedimentation unit, 320-buoyancy opening and closing mechanism, 321-buoyancy component, 322-first connecting rod, 323-first gate plate, 324-second connecting rod, 325-second gate plate, 326-first guide component, 327-second guide component, 331-drainage main pipeline, 332-drainage branch pipeline, 340-float normally closed switch, 341-drainage outlet, 342-sealing ball, 343-ball cage structure, 344-float.

DETAILED DESCRIPTION

1 , the dust filtration system for bridge engineering construction of the present invention includes an exhaust device 100, an aeration and dust removal device 200 and a wastewater sedimentation device 300. The exhaust device 100, the aeration and dust removal device 200 and the wastewater sedimentation device 300 can be integrated into a movable body, and can be moved to a place where dust filtration is required according to the changing needs of the construction site; of course, it can be integrated into a fixed place and used in places where large dust is generated at a fixed position during the entire construction process. Those skilled in the art can select the layout method according to the actual needs of the site. Among them, the exhaust device 100 mainly adopts the design of exhaust pipe integrated exhaust fan, which is used to suck the dust generated during the construction of the bridge project, while the aeration dust removal device 200 adopts a pool structure with an integrated aeration plate at the bottom. The dust extracted by the exhaust device 100 is passed into the aeration plate of the aeration dust removal device 200 through a pipeline. The pool structure is filled with clean water. The dust can be repeatedly mixed with water after aeration and finally remain in the water. In the construction process of the bridge project, most of the dust can be purified by water, so the dust can be filtered and purified by the aeration dust removal device 200. The wastewater sedimentation device 300 is connected to the aeration dust removal device 200, and is used to pass the dust-absorbed wastewater into the wastewater sedimentation device 300 for sedimentation and separation. The wastewater sedimentation device 300 has a clean water outlet and a sludge outlet. The clean water outlet is connected to the aeration dust removal device 200 so that the clean water after sedimentation can be recycled.

2-4, the wastewater sedimentation device 300 includes a plurality of sedimentation units 310, each of which adopts a rectangular box structure, for example, a box with a length of 100 cm, a width of 100 cm, and a thickness of 20 cm. After the sedimentation units 310 are arranged side by side in the thickness direction, a rectangular structure with a certain length can be formed. For example, 20 sedimentation units 310 are arranged side by side, then a rectangular structure with a length of 100 cm, a width of 100 cm, and a thickness of 400 cm is formed. The aeration and dust removal device 200 is provided with a drainage channel connecting the plurality of sedimentation units 310. In this embodiment, the drainage channel is directly arranged above one side of the rectangular structure after the 20 sedimentation units 310 are arranged. Each sedimentation unit 310 is provided with a water inlet, which is connected to the drainage channel through the water inlet, so that wastewater can be discharged into each sedimentation unit 310 through the drainage channel. The sedimentation unit 310 is provided with a buoyancy opening and closing mechanism 320, which can close the drainage channel where the sedimentation unit 310 is located and open the water inlet of the adjacent sedimentation unit 310 after a certain amount of wastewater is loaded into the sedimentation unit 310. In this embodiment, the wastewater in the aeration dust removal device 200 is introduced into the drainage channel through one end of the drainage channel, and then flows into the sedimentation unit 310 at the end. After the wastewater is introduced into the sedimentation unit 310 and the prescribed amount is waited for, the buoyancy opening and closing mechanism 320 can be activated, thereby closing the drainage channel connected to the water inlet in the sedimentation unit 310, and simultaneously opening the next sedimentation unit 310 to continue to introduce wastewater.

3-5, specifically, the buoyancy opening and closing mechanism 320 includes a buoyancy component 321, a first guide component 326, a first gate 323, a second guide component 327, and a second gate 325. The buoyancy component 321 is arranged in the sedimentation unit 310 and is guided by the first guide component 326. The buoyancy component 321 is made of a material having buoyancy, and the first guide component 326 is made of a guide rod or a guide rail to keep the buoyancy component 321 moving in the vertical direction. The first gate 323 is connected to the buoyancy component 321 through a first connecting rod 322, and the first gate 323 is guided by the second guide component 327. The buoyancy component 321 can drive the first gate 323 to move on the second guide component 327 through the first connecting rod 322, thereby opening or closing the drainage channel where the sedimentation unit 310 is located. The second guide component 327 also adopts the arrangement mode of guide rod or guide rail, and is arranged in direction according to the height of the drainage channel. In addition, the second guide component 327 in this embodiment is arranged horizontally, which can switch the first gate plate 323 between the position of inserting into the drainage channel to intercept the sedimentation unit 310 and retracting into the sedimentation unit 310 to load wastewater.

The second gate plate 325 is used to close the water inlet of the sedimentation unit 310. The first gate plate 323 is also connected to the second gate plate 325 of the adjacent sedimentation unit 310 through the second connecting rod 324. When the first gate plate 323 closes the drainage channel where the sedimentation unit 310 is located, the second gate plate 325 of the adjacent sedimentation unit 310 can be driven to move through the second connecting rod 324, thereby opening the water inlet of the adjacent sedimentation unit 310.

In order to realize the sequential water inflow from the beginning to the end in this embodiment, first of all, the last sedimentation unit 310 does not need to be provided with the second gate plate 325 at the water inlet position. After the drainage channel is opened, the wastewater enters the last sedimentation unit 310 first, and the water inlets of other sedimentation units 310 are in a closed state. When the wastewater loaded into the last sedimentation unit 310 can float the buoyancy component 321, the first gate plate 323 is driven to move along the second guide component 327 through the buoyancy component 321 and the first connecting rod 322 of the first gate plate 323, so that the first gate plate 323 blocks the drainage channel. At this time, the drainage channel stops water from entering the last sedimentation unit 310. When the first gate plate 323 moves, the adjacent sedimentation unit 310 (or the second one) is also driven through the second connecting rod 324. The second gate plate 325 of each sedimentation unit 310 moves, and the second gate plate 325 is located at the position of the drain outlet 341, and is arranged vertically with the first gate plate 323. The movement of the second gate plate 325 can open the water inlet of the sedimentation unit 310 where it is located. When the first sedimentation unit 310 at the end is closed by the first gate plate 323, the second gate plate 325 of the second sedimentation unit 310 is just opened. Therefore, the first sedimentation unit 310 stops taking in water, and the second sedimentation unit 310 starts taking in water. By installing according to this principle, the single sedimentation unit 310 can take in water in sequence from the end of the drainage channel, and complementary interference is achieved, which can ensure that when each sedimentation unit 310 can be precipitated, other sedimentation units 310 can take in water without affecting them.

When some of the sedimentation units 310 have completed sedimentation and drainage, but other sedimentation units 310 have not completed sedimentation and drainage or may still be taking in water, in order to improve the utilization rate of the sedimentation units 310, the drainage channel also includes a drainage main pipe 331 and a drainage branch pipe 332. The drainage main pipe 331 is connected to all the sedimentation units 310 in sequence. One end of the drainage branch pipe 332 is connected to the drainage main pipe 331, and the other end is provided with a plurality of connecting parts, which are respectively connected to the drainage main pipe 331 at a certain distance through the connecting parts, and each connecting part is provided with a solenoid valve. At this time, the drainage branch pipes 332 corresponding to the several sedimentation units 310 that have completed sedimentation and drainage can be opened, and drainage can be carried out from the drainage branch pipes 332, so as to continue to start these sedimentation units 310, so that these sedimentation units 310 can continue to achieve sedimentation and drainage. The opening and closing of the drainage branch pipe 332 can be controlled by the solenoid valve program to open at a time, or a manual valve can be used to open manually.

Referring to Fig. 5 and Fig. 6, a plurality of water outlets are also provided on both sides of the sedimentation unit 310, and a float normally closed switch 340 is provided at each water outlet, which is used to open the water outlet when the liquid level drops. The water outlets on both sides of the sedimentation unit 310 are arranged alternately in the vertical direction. Specifically, the float normally closed switch 340 includes a ball cage structure 343 arranged in the vertical direction, a float is arranged in the ball cage structure 343, a blocking ball 342 is arranged in the water outlet, and the float and the blocking ball 342 are connected by a connecting line; the highest floating position of the buoyancy component 321 is vertically lower than the floating position of the float of the float normally closed switch 340 located at the top; in the vertical direction, the lowest floating position of the float of the float normally closed switch 340 is lower than the highest floating position of the float of the next float normally closed switch 340. When the first gate 323 closes the drainage channel, the buoyancy component 321 also stops floating and is in a short-term stay state. The stay position of the buoyancy component 321 is lower than the floating position of the topmost float normally closed switch 340, that is, the topmost float normally closed switch 340 is not normally closed at this time, so the drainage starts at this time, and the sedimentation of wastewater starts from now on. At the same time, the drainage of the topmost water outlet also starts. The water outlet can be designed with a valve to adjust the size of the drainage volume. The drainage volume can generally be set according to the approximate sedimentation speed. When the water level line is lower than the topmost water outlet, the float in the float normally closed switch 340 at the next height has fallen to the bottom of the ball cage structure 343, releasing the closure of the second water outlet, and the second water outlet has begun to discharge water. By analogy, the drainage can be completed step by step to achieve the removal of clean water after sedimentation.

The outlet at the lowest end is connected to the sludge pool, and the other outlets are connected to the aeration dust removal device 200, so that the last high-mud content sewage discharged can be uniformly collected and processed. At the same time, the bottom of the sedimentation unit 310 adopts an inclined structure that is inclined toward the outlet connected to the sludge pool, and the water inlet of the sedimentation unit 310 is arranged on the opposite side of the outlet connected to the sludge pool. After the sedimentation unit 310 completes the sedimentation separation and drainage, the newly incoming sewage can fall from the water inlet and flush the inclined bottom structure very well. At the beginning, the float ball normally closed switch 340 of the outlet is still in an open state due to the lack of buoyancy. Therefore, the newly incoming wastewater can flush the bottom of the sedimentation unit 310 very well, and cooperate with the inclined structure to quickly complete the flushing of the sludge after the last sedimentation. When the page reaches a certain height, the float ball normally closed switch 340 is closed and water storage begins.

A clean water temporary storage device 400 is provided between the wastewater sedimentation device 300 and the aeration and dust removal device 200. Since the water flow at the water outlet is small, it can be well collected and temporarily stored by the clean water temporary storage device 400. The aeration and dust removal device 200 is also connected to a clean water supply device 500 for replenishing clean water to maintain the normal operation of the aeration and dust removal device 200.

This embodiment also provides a filtering method based on the above-mentioned dust filtering system for bridge engineering construction, comprising the following steps:

The dust is extracted by the exhaust device 100 and then passed into the aeration dust removal device 200. The dust is purified and filtered by the water in the aeration dust removal device 200. The wastewater generated in the aeration dust removal device 200 is passed into the wastewater sedimentation device 300 for separation. The separated clean water is then returned to the aeration dust removal device 200 for use, and the sludge is centrally treated.

Among them, the separation of the wastewater sedimentation device 300 relies on the drainage channel to enter the sedimentation unit 310 located at the end of the drainage channel. After it is full, the corresponding drainage channel is closed by the buoyancy opening and closing mechanism 320, and the water inlet of an adjacent sedimentation unit 310 is opened at the same time to allow water to enter the next sedimentation unit 310, and so on, and the water entry of each sedimentation unit 310 is completed in sequence; after each sedimentation unit 310 is filled with water, sedimentation begins, and the topmost float normally closed switch 340 is first opened to release clean water, which is then collected and returned to the aeration dust removal device 200 for use. When the water level drops to the position of the next float normally closed switch 340, the float normally closed switch 340 is started to continue to release clean water, and so on, from top to bottom, the clean water after sedimentation separation is released.

When some of the sedimentation units 310 have completed sedimentation drainage, but other sedimentation units 310 have not yet completed sedimentation drainage or may still be taking in water, the drainage branch pipes 332 corresponding to the sedimentation units 310 that have completed sedimentation drainage are opened, and water is discharged from the drainage branch pipes 332, so as to continue to start these sedimentation units 310 and allow these sedimentation units 310 to continue to achieve sedimentation drainage.

Claims (8)

1. The utility model provides a dust filtration system for bridge engineering construction, includes updraft ventilator, aeration dust collector and waste water precipitation device, updraft ventilator is used for sucking the dust that produces in the bridge engineering work progress, aeration dust collector is connected with updraft ventilator, can let in aeration dust collector with the wind of updraft ventilator extraction purifying, waste water precipitation device connects aeration dust collector is used for letting in dust absorption waste water precipitation device precipitation separation, waste water precipitation device has clear water export and mud export, clear water export is connected to aeration dust collector to make clear water cyclic utilization after the sediment, its characterized in that:

The wastewater sedimentation device comprises a plurality of sedimentation units, wherein the aeration dust removal device is connected with a drainage channel, the drainage channel is communicated with the plurality of sedimentation units, a buoyancy opening and closing mechanism is arranged in the sedimentation units, and the drainage channel where the sedimentation units are positioned can be closed after wastewater is filled in the sedimentation units, and water inlets of adjacent sedimentation units are simultaneously opened;

The buoyancy opening and closing mechanism comprises a buoyancy component, a first guide component, a first flashboard, a second guide component and a second flashboard, wherein the buoyancy component is arranged in the sedimentation unit and is guided and arranged through the first guide component, the first flashboard is connected with the buoyancy component through a first connecting rod, the first flashboard is guided and arranged through the second guide component, the buoyancy component can drive the first flashboard to move on the second guide component through the first connecting rod so as to open or close a drainage channel where the sedimentation unit is located, the second flashboard is used for closing a water inlet of the sedimentation unit, the first flashboard is connected with the second flashboard of an adjacent sedimentation unit through the second connecting rod, and when the first flashboard closes the drainage channel where the sedimentation unit is located, the second flashboard of the adjacent sedimentation unit can be driven to move through the second connecting rod so as to open a water inlet of the adjacent sedimentation unit.

2. The dust filtering system for bridge construction according to claim 1, wherein the normally closed float switch comprises a ball cage structure arranged in a vertical direction, wherein a float ball is arranged in the ball cage structure, a blocking ball is arranged in the water outlet, the float ball is connected with the blocking ball through a connecting wire, the highest floating position of the buoyancy member is vertically lower than the floating position of the float ball of the normally closed float switch positioned at the uppermost position, and the lowest floating position of the float ball of the normally closed float switch is lower than the highest floating position of the float ball of the normally closed float switch positioned at the next position in the vertical direction.

3. The dust filtering system for bridge construction according to claim 1, wherein the water outlet at the lowest end is connected to a sludge tank, and the other water outlets are connected to an aeration dust removing device.

4. A dust filtration system for bridge construction according to claim 3, wherein the bottom of the sedimentation unit adopts a slope structure inclined to the water outlet connected to the sludge tank, and the water inlet of the sedimentation unit is disposed on the opposite side to the water outlet connected to the sludge tank.

5. The dust filtering system for bridge construction according to any one of claims 1 to 4, wherein the drainage channel further comprises a main drainage pipe and branch drainage pipes, the main drainage pipe is sequentially connected to all the precipitation units, one end of the branch drainage pipe is connected to the main drainage pipe, a plurality of connection parts are provided at the other end of the branch drainage pipe, the branch drainage pipe is connected to the main drainage pipe at a certain distance through the connection parts, and each connection part is provided with an electromagnetic valve.

6. The dust filtering system for bridge construction according to claim 5, wherein a clear water temporary storage device is further arranged between the wastewater precipitation device and the aeration dust removal device.

7. The dust filtering system for bridge construction work according to claim 6, wherein the aeration dust removing device is further connected with a clean water supply device.

8. A filtering method based on the dust filtering system for bridge engineering construction according to any one of claims 1-2, characterized by comprising the following steps:

Extracting dust through an air draft device, then introducing the dust into an aeration dust removing device, purifying and filtering the dust by means of water in the aeration dust removing device, introducing waste water generated in the aeration dust removing device into a waste water precipitation device for separation, returning the separated clear water into the aeration dust removing device for use, and carrying out centralized treatment on sludge;

The separation of the wastewater sedimentation device is that the wastewater enters the sedimentation unit positioned at the tail end of the drainage channel by means of the drainage channel, after the wastewater is filled, the corresponding drainage channel is closed by the buoyancy opening and closing mechanism, the water inlet of the next sedimentation unit is opened, water inflow of the next sedimentation unit is performed, and the like, and water inflow of each sedimentation unit is completed sequentially, after each sedimentation unit is filled with water, sedimentation is started, the uppermost floating ball normally closed switch is firstly opened to discharge clear water, the clear water is returned to the aeration dust removal device after collection, the floating ball normally closed switch is started when the water surface falls to the position of the next floating ball normally closed switch, clear water is continuously discharged, and the clear water after sedimentation separation is discharged sequentially from top to bottom.