Two-stage air flotation deslagging system for shale oil flowback fluid wastewater treatment

Abstract

The invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a two-stage air flotation deslagging system for shale oil flowback fluid wastewater treatment, which comprises an air flotation assembly, wastewater enters the air flotation assembly through a wastewater inlet pipe, a gas dissolving assembly is arranged on the side surface of the air flotation assembly, and the gas dissolving assembly discharges water dissolved with gas into the air flotation assembly through a connecting pipe. Gas is released from the water, a large number of bubbles are generated in the wastewater in the air flotation assembly, the large number of bubbles move upwards, dirt in the sewage is combined with the bubbles to form dirt particles, the dirt particles float to the upper surface of the sewage, a scum scraping assembly is arranged at the upper end of the air flotation assembly, and scum collecting assemblies are arranged on the two sides of the air flotation assembly. Dirt particles are scraped into the scum collecting assemblies on the two sides of the air flotation assembly through the scum scraping assembly to be filtered and collected, water in the dirt particles is further discharged, the system is reasonable in design and high in automation degree, and the wastewater treatment efficiency is remarkably improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of industrial wastewater treatment, and particularly relates to a two-stage air flotation slag removal system for treating shale oil return flow wastewater. Background Art

[0002] Shale oil is a non-conventional petroleum resource, and a large amount of return flow wastewater is generated during its mining process. The return flow wastewater contains a large amount of suspended solids, oil substances and other pollutants. If it is directly discharged without effective treatment, it will cause serious pollution to the environment;

[0003] Air flotation technology is a commonly used water treatment method. By introducing fine bubbles into the water, suspended substances adhere to the surface of the bubbles and float to the water surface with the bubbles, thereby achieving the purpose of solid-liquid separation. The air flotation method has the advantages of fast treatment speed, small floor area, simple operation, etc., and is suitable for treating wastewater containing a large amount of suspended solids and oil substances;

[0004] For example, a sewage treatment air flotation device with the patent application number CN202410526550.0 includes an air flotation tank, a dissolved air mechanism and a slag scraping mechanism. The dissolved air mechanism is installed on the outer wall of the air flotation tank. A release mechanism is installed in the air flotation tank, and the release mechanism is connected to the dissolved air mechanism through a pipeline. The release mechanism is used to release the gas generated by the dissolved air mechanism into the air flotation tank. The slag scraping mechanism is installed above the air flotation tank, and a driving mechanism is also installed in the air flotation tank. However, the disadvantage of this technical solution is that after the slag scraping mechanism scrapes off the suspended substances, a large amount of water is scraped away together with the suspended substances, resulting in waste of water resources. Summary of the Invention

[0005] The purpose of the present invention is to provide a two-stage air flotation slag removal system for treating shale oil return flow wastewater to solve the problems in the prior art. The specific technical solutions are as follows:

[0006] A two-stage air flotation slag removal system for treating shale oil return flow wastewater includes an air flotation component. Wastewater enters the air flotation component through a wastewater inlet pipe. A dissolved air component is arranged on the side of the air flotation component. The dissolved air component discharges the water dissolved with gas into the air flotation component through a connecting pipe. A floating slag scraping component is arranged at the upper end of the air flotation component, and floating slag collection components are arranged on both sides of the air flotation component.

[0007] Further, the air flotation component includes an air flotation tank. A first guide plate and a second guide plate are arranged in parallel in the air flotation tank. The first guide plate and the second guide plate divide the inside of the air flotation tank into a primary air flotation chamber and a secondary air flotation chamber. There is a gap between the first guide plate and the bottom of the air flotation tank. Diffusion plates are arranged in both the primary air flotation chamber and the secondary air flotation chamber. The dissolved air component is communicated with the diffusion plates through two connecting pipes respectively. Mesh holes are arranged on both the flat surface and the inclined surface of the diffusion plates.

[0008] Further, the wastewater inlet pipe includes a first wastewater inlet pipe and a second wastewater inlet pipe, and the first wastewater inlet pipe and the second wastewater inlet pipe are fixedly connected through a thickened pipe.

[0009] Further, a protective cover is installed on the top of the air flotation tank. There are two air outlet holes on the protective cover. The second wastewater inlet pipe passes through the protective cover, and its end is located above the diffusion plate in the primary air flotation chamber.

[0010] Further, the dissolved air assembly includes an air inlet pipe. A gas pump is provided in the middle of the air inlet pipe. The lower end of the air inlet pipe is connected with a diffusion column. The diffusion column is located in the dissolved air tank. The dissolved air tank is communicated with two diffusion plates respectively through two connecting pipes. Control valves are provided on the connecting pipes. The dissolved air tank is communicated with the secondary air flotation chamber through a first water guide pipe. A first water pump is provided in the middle of the first water guide pipe. The secondary air flotation chamber is communicated with the outside through a drain pipe. A ball valve is provided in the drain pipe.

[0011] Further, the scum scraping assembly includes a first motor. The first motor is fixed on the outer wall of the air flotation tank. The output end of the first motor is connected with a first rotating shaft. The first rotating shaft is in transmission cooperation connection with a first belt. The first belts located on the upper and lower sides of the first rotating shaft are respectively fixedly connected with two connecting blocks. The connecting blocks are fixedly connected with a support plate. The support plate is rotatably connected with a scraper. A baffle is provided at the lower end of the support plate. The scraper is fixedly connected with a gear shaft. The gear shaft is in gear meshing transmission with a rack block. The rack block is slidably connected with the air flotation tank. The rack block is in threaded connection with a fastening screw. The front end of the fastening screw abuts against the outer wall of the air flotation tank.

[0012] Further, the scum collection assembly includes a housing. The housing is fixedly connected with a second motor. The output end of the second motor is connected with a second rotating shaft. The second rotating shaft is in transmission cooperation connection with a third rotating shaft through a second belt. Both the second rotating shaft and the third rotating shaft are in transmission cooperation connection with a mesh conveyor belt. The third rotating shaft is fixedly connected with a first gear. The first gear is in gear meshing transmission with a second gear. The second gear is in gear meshing transmission with a third gear. The second gear is fixedly connected with a first brush roller. The third gear is fixedly connected with a second brush roller. The first brush roller and the second brush roller rotate on the inner and outer sides of the mesh conveyor belt respectively.

[0013] Further, a partition is fixed in the housing. The outer wall of the air flotation tank, the inner wall of the housing and the partition enclose a liquid storage chamber. The liquid storage chamber is communicated with one end of a second water guide pipe. The other end of the second water guide pipe is fixed on the thickened pipe. A second water pump is provided in the middle of the second water guide pipe. The upper end of the partition abuts against the lower side of the mesh conveyor belt. A U-shaped groove is fixed on the side surface of the partition.

[0014] Further, a support frame is fixed in the housing. The support frame is fixedly connected with a third motor. The output end of the third motor is connected with a turntable. The support frame is rotatably connected with the lower end of a rotating rod. The rotating rod is slidably connected with a first slider. The first slider is rotatably connected with a small cylinder on the turntable. The rotating rod is slidably connected with a second slider. The second slider is rotatably connected with a push plate. The push plate slides in the U-shaped groove.

[0015] Furthermore, slag discharge ports are provided on both sides of the housing. Both of the two slag discharge ports are communicated with the U-shaped groove. Collection boxes are provided on both sides of the housing. A filter screen is provided inside the collection box. A water storage tank is provided at the lower end of the filter screen. The water storage tank is communicated with the liquid storage chamber through the third water guide pipe. A one-way valve is provided in the middle of the third water guide pipe. A door panel is provided on the side of the collection box.

[0016] The advantages of the present invention are as follows:

[0017] 1. Wastewater enters the air flotation assembly through the wastewater inlet pipe. The dissolved air assembly discharges the water dissolved with gas into the air flotation assembly through the connecting pipe. The gas is released from the water, and a large number of bubbles are generated in the wastewater in the air flotation assembly. The large number of bubbles move upward, and the contaminants in the sewage combine with the bubbles to form contaminant particles that float to the upper surface of the sewage. The contaminant particles are scraped into the scum collection assemblies on both sides of the air flotation assembly by the scum scraping assembly for filtration and collection, and the water in the contaminant particles is further discharged. The system is reasonably designed and has a high degree of automation, significantly improving the wastewater treatment efficiency.

[0018] 2. The scum scraping assembly can effectively scrape away the contaminant particles floating on the upper layer of the wastewater, preventing the accumulation of contaminant particles and thus affecting the air flotation effect.

[0019] 3. The scum collection assembly can filter the water in the contaminant particles multiple times, reducing the waste of water resources. At the same time, relatively dry contaminant particles are obtained, which is convenient for their transfer and treatment. Description of the Drawings

[0020] Figure 1 is the schematic diagram of the overall structure of the present invention Figure 1 ;

[0021] Figure 2 is the schematic diagram of the overall structure of the present invention Figure 2 ;

[0022] Figure 3 is the schematic diagram of the structure of the dissolved air assembly of the present invention;

[0023] Figure 4 is the schematic diagram of the structure of the air flotation assembly of the present invention;

[0024] Figure 5 is the schematic diagram of the structure of the wastewater inlet pipe of the present invention;

[0025] Figure 6 is the schematic diagram of the structure of the scum scraping assembly of the present invention Figure 1 ;

[0026] Figure 7 is Figure 6 the partial enlarged view at A in

[0027] Figure 8 is the schematic diagram of the structure of the scum scraping assembly of the present invention Figure 2 ;

[0028] Figure 9 For Figure 8 Partial enlarged view at position B in

[0029] Figure 10 Schematic structure of the scum collection component of the present invention Figure 1 ;

[0030] Figure 11 Schematic structure of the scum collection component of the present invention Figure 2 ;

[0031] Figure 12 Schematic structure of the scum collection component of the present invention Figure 3 ;

[0032] Figure 13 For Figure 12 Partial enlarged view at position C in

[0033] Explanation of marks in the figure:

[0034] Air inlet pipe 1; air pump 2; diffusion column 3; dissolved air tank 4; connecting pipe 5; control valve 6; diffusion disc 7; mesh holes 8; air flotation tank 9; first deflector 10; second deflector 11; first waste water inlet pipe 12; second waste water inlet pipe 13; thickened pipe 14; first water guide pipe 15; first water pump 16; drain pipe 17; first motor 18; first rotating shaft 19; first belt 20; connecting block 21; support plate 22; scraper 23; baffle 24; gear shaft 25; rack block 26; fastening screw 27; housing 28; second motor 29; second rotating shaft 30; second belt 31; third rotating shaft 32; first gear 33; second gear 34; third gear 35; first rotary brush 36; second rotary brush 37; mesh conveyor belt 38; partition 39; third motor 40; support frame 41; turntable 42; rotating rod 43; first slider 44; second slider 45; U-shaped groove 46; push plate 47; second water guide pipe 48; second water pump 49; slag discharge port 50; collection box 51; filter screen 52; water storage tank 53; third water guide pipe 54; door panel 55; protective cover 56; air outlet hole 57. Specific implementation mode

[0035] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0036] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0037] Embodiment 1

[0038] As Figures 1 - 13 shown, the two-stage air flotation slag removal system for shale oil flowback fluid wastewater treatment includes an air flotation assembly. Wastewater enters the air flotation assembly through a wastewater inlet pipe. A dissolved air assembly is provided on the side of the air flotation assembly. The dissolved air assembly discharges the water dissolved with gas into the air flotation assembly through a connecting pipe 5. A scum scraping assembly is provided at the upper end of the air flotation assembly, and scum collection assemblies are provided on both sides of the air flotation assembly;

[0039] The working principle of the above technical solution: Wastewater enters the air flotation assembly through the wastewater inlet pipe. The dissolved air assembly discharges the water dissolved with gas into the air flotation assembly through the connecting pipe 5. The gas is released from the water, generating a large number of bubbles in the wastewater in the air flotation assembly. The large number of bubbles move upward, and the contaminants in the sewage combine with the bubbles to form contaminant particles that float to the upper surface of the sewage. The scum scraping assembly scrapes the contaminant particles into the scum collection assemblies on both sides of the air flotation assembly for filtration and collection, and further discharges the water in the contaminant particles. The system is reasonably designed and has a high degree of automation, significantly improving the wastewater treatment efficiency.

[0040] Embodiment 2

[0041] As Figures 1 - 13 shown, the air flotation assembly includes an air flotation tank 9. A first guide plate 10 and a second guide plate 11 are arranged in parallel in the air flotation tank 9. The first guide plate 10 and the second guide plate 11 divide the inside of the air flotation tank 9 into a primary air flotation chamber and a secondary air flotation chamber. A gap is left between the first guide plate 10 and the bottom of the air flotation tank 9. Diffusion plates 7 are provided in both the primary air flotation chamber and the secondary air flotation chamber. The dissolved air assembly is communicated with the diffusion plates 7 through two connecting pipes 5 respectively. Mesh holes 8 are provided on both the flat surface and the inclined surface of the diffusion plates 7;

[0042] The wastewater inlet pipe includes a first wastewater inlet pipe 12 and a second wastewater inlet pipe 13. The first wastewater inlet pipe 12 and the second wastewater inlet pipe 13 are fixedly connected through a thickened pipe 14;

[0043] A protective cover 56 is installed on the top of the air flotation tank 9. Two air outlet holes 57 are provided on the protective cover 56. The second wastewater inlet pipe 13 passes through the protective cover 56, and its end is located above the diffusion plate 7 in the primary air flotation chamber;

[0044] Working principle of the above technical solution: Sewage enters the first - stage air - flotation chamber through the waste - water inlet pipe. The dissolved - air component discharges the water dissolved with gas into the diffusion plate 7 in the first - stage air - flotation chamber and the second - stage air - flotation chamber through the connecting pipe 5, releasing a large number of bubbles. The bubbles move upward through the mesh holes 8 on the diffusion plate 7, and the bubbles combine with the contaminants in the sewage to form contaminant particles, which float to the upper surface of the sewage in the first - stage air - flotation chamber. Due to the principle of the communicating vessel, the air - floated sewage in the first - stage air - flotation chamber enters the second - stage air - flotation chamber through the first guide plate 10 and the second guide plate 11 for further air - flotation treatment. Through two - stage air - flotation treatment, the sewage purification rate is improved;

[0045] The diffusion plate 7 is provided with mesh holes 8 on multiple sides, which improves the range of bubble diffusion;

[0046] The protective cover 56 protects the air - flotation component, the scum scraping component and the two scum collection components, playing a role in protecting the equipment components. The protective cover 56 is provided with two air - outlet holes 57, which is convenient for the bubbles in the first - stage air - flotation chamber and the second - stage air - flotation chamber to float out and be discharged, preventing the air pressure in the first - stage air - flotation chamber and the second - stage air - flotation chamber from being too high, resulting in slow gas release and affecting the air - flotation effect;

[0047] The water flowing back from the two scum collection components enters the thickened pipe 14, converges with the sewage flowing out of the first waste - water inlet pipe 12, and then enters the second waste - water inlet pipe 13 together and flows into the first - stage air - flotation chamber, effectively preventing the sewage flowing out of the first waste - water inlet pipe 12 from mistakenly entering the scum collection components.

[0048] Embodiment Three

[0049] As Figures 1 - 13 shown, the dissolved - air component includes an air inlet pipe 1. A gas pump 2 is provided in the middle of the air inlet pipe 1. The lower end of the air inlet pipe 1 is connected to a diffusion column 3. The diffusion column 3 is located in a dissolved - air tank 4. The dissolved - air tank 4 is connected to two diffusion plates 7 through two connecting pipes 5 respectively. A control valve 6 is provided on the connecting pipe 5. The dissolved - air tank 4 is connected to the second - stage air - flotation chamber through a first water guide pipe 15. A first water pump 16 is provided in the middle of the first water guide pipe 15. The second - stage air - flotation chamber is connected to the outside through a drain pipe 17. A ball valve is provided in the drain pipe 17;

[0050] Working principle of the above technical solution: In the initial state, the control valve 6 is in the closed state. Water is injected into the dissolved - air tank 4 through a water - cleaning pipe (not shown). The gas pump 2 sucks the outside air into the diffusion column 3, and the gas diffuses into the water in the dissolved - air tank 4 through the small holes on the diffusion column 3. Open the control valve 6 to make the connecting pipe 5 conduct. The water containing a large amount of gas enters the diffusion plate 7 through the connecting pipe 5 and releases the gas in the diffusion plate 7 to generate bubbles. Start the first water pump 16 to pump the purified water in the second - stage air - flotation chamber into the dissolved - air tank 4 through the first water guide pipe 15. Open the ball valve on the drain pipe 17, and the purified water in the second - stage air - flotation chamber can be discharged through the drain pipe 17.

[0051] Example 4

[0052] As Figures 1 - 13 shown, the scum scraping assembly includes a first motor 18, which is fixed on the outer wall of the air flotation tank 9. The output end of the first motor 18 is connected to a first rotating shaft 19. The first rotating shaft 19 is in transmission connection with a first belt 20. The first belts 20 on the upper and lower sides of the first rotating shaft 19 are respectively fixedly connected to two connecting blocks 21. The connecting blocks 21 are fixedly connected to a support plate 22. The support plate 22 is rotatably connected to a scraper 23. A baffle 24 is provided at the lower end of the support plate 22. The scraper 23 is fixedly connected to a gear shaft 25. The gear shaft 25 is in gear meshing transmission with a rack block 26. The rack block 26 is slidably connected to the air flotation tank 9. The rack block 26 is in threaded connection with a fastening screw 27. The front end of the fastening screw 27 abuts against the outer wall of the air flotation tank 9;

[0053] The working principle of the above technical solution: Start the first motor 18, drive the first rotating shaft 19 to rotate, drive the first belt 20 to rotate, drive the connecting blocks 21 on the upper and lower sides of the first belt 20 to move towards both ends respectively, drive the two support plates 22 to move towards both ends respectively, drive the gear shaft 25 and the rack block 26 to perform gear meshing rotation, drive the gear shaft 25 to rotate, drive the scraper 23 to rotate to the vertical state, and then be blocked by the baffle 24 and unable to rotate further, so that the gear shaft 25 cannot rotate further. The gear shaft 25 pulls the rack block 26 to move on the air flotation tank 9, and the vertical scraper 23 scrapes the dirt particles floating on the upper surface of the wastewater into the scum collection assembly;

[0054] Start the first motor 18 again, drive the first rotating shaft 19 to rotate in the opposite direction, drive the first belt 20 to rotate in the opposite direction, drive the connecting blocks 21 on the upper and lower sides of the first belt 20 to move towards each other, drive the two support plates 22 to move towards each other, drive the gear shaft 25 and the rack block 26 to perform gear meshing rotation, drive the gear shaft 25 to rotate, drive the scraper 23 to rotate 180 degrees and fit with the support plate 22. The scraper 23 cannot rotate further, so that the gear shaft 25 cannot rotate further. The gear shaft 25 pulls the rack block 26 to move on the air flotation tank 9. The scraper 23 rotated 180 degrees is separated from the upper surface of the wastewater to prevent scraping the dirt particles in the opposite direction;

[0055] The scum scraping assembly can effectively scrape away the dirt particles floating on the upper layer of the wastewater, preventing the accumulation of dirt particles and thus affecting the air flotation effect.

[0056] Example 5

[0057] As Figures 1 - 13As shown in the figure, the scum collection assembly includes a housing 28, the housing 28 is fixedly connected to the second motor 29, the output end of the second motor 29 is connected to the second rotating shaft 30, the second rotating shaft 30 is drivingly connected to the third rotating shaft 32 through the second belt 31, both the second rotating shaft 30 and the third rotating shaft 32 are drivingly connected to the mesh conveyor belt 38, the third rotating shaft 32 is fixedly connected to the first gear 33, the first gear 33 is in meshing transmission with the second gear 34, the second gear 34 is in meshing transmission with the third gear 35, the second gear 34 is fixedly connected to the first rolling brush 36, the third gear 35 is fixedly connected to the second rolling brush 37, and the first rolling brush 36 and the second rolling brush 37 rotate on the inner and outer sides of the mesh conveyor belt 38 respectively;

[0058] A partition 39 is fixed inside the housing 28. The outer wall of the air flotation tank 9, the inner wall of the housing 28 and the partition 39 enclose a liquid storage chamber. The liquid storage chamber is communicated with one end of the second water guide pipe 48, the other end of the second water guide pipe 48 is fixed on the thickened pipe 14, a second water pump 49 is arranged in the middle of the second water guide pipe 48, the upper end of the partition 39 abuts against the lower side of the mesh conveyor belt 38, and a U-shaped groove 46 is fixed on the side surface of the partition 39;

[0059] The working principle of the above technical solution: The dirt particles are scraped onto the mesh conveyor belt 38 by the scraper 23. Start the second motor 29 to drive the second rotating shaft 30 to rotate, drive the third rotating shaft 32 to rotate through the second belt 31, and drive the mesh conveyor belt 38 to rotate, so as to convey the dirt particles into the U-shaped groove 46. A large number of small mesh holes are provided on the mesh conveyor belt 38. During the conveying process of the dirt particles, the water in the dirt particles can fall into the liquid storage chamber through the small mesh holes. The upper end of the partition 39 contacts the outer surface of the mesh conveyor belt 38, and the dirt particles adhered to the mesh conveyor belt 38 can be scraped off;

[0060] The rotation of the third rotating shaft 32 drives the first gear 33 to rotate, drives the second gear 34 to rotate, drives the third gear 35 to rotate, drives the first rolling brush 36 and the second rolling brush 37 to rotate, and the first rolling brush 36 and the second rolling brush 37 respectively brush the inner and outer sides of the mesh conveyor belt 38 to reduce the blockage of the small mesh holes on the mesh conveyor belt 38;

[0061] Start the second water pump 49, pump the water in the liquid storage chamber into the thickened pipe 14 through the second water guide pipe 48, and converge with the wastewater entering through the first wastewater inlet pipe 12, and enter the first-stage air flotation chamber together through the second wastewater inlet pipe 13;

[0062] Through the scum collection assembly, the water in the dirt particles can be filtered multiple times, reducing the waste of water resources. At the same time, relatively dry dirt particles are obtained, which is convenient for their transfer and treatment.

[0063] Embodiment Six

[0064] As Figures 1 - 13As shown, a support frame 41 is fixed inside the housing 28. The support frame 41 is fixedly connected to the third motor 40. The output end of the third motor 40 is connected to the turntable 42. The support frame 41 is rotatably connected to the lower end of the rotating rod 43. The rotating rod 43 is slidably connected to the first slider 44. The first slider 44 is rotatably connected to the small cylinder on the turntable 42. The rotating rod 43 is slidably connected to the second slider 45. The second slider 45 is rotatably connected to the push plate 47. The push plate 47 slides in the U-shaped groove 46.

[0065] On both sides of the housing 28, there are slag discharge ports 50. Both of the two slag discharge ports 50 are communicated with the U-shaped groove 46. On both sides of the housing 28, there are collection boxes 51. A filter screen 52 is arranged inside the collection box 51. A water storage tank 53 is arranged at the lower end of the filter screen 52. The water storage tank 53 is communicated with the liquid storage chamber through the third water guide pipe 54. A one-way valve is arranged in the middle of the third water guide pipe 54. A door panel 55 is arranged on the side of the collection box 51.

[0066] The working principle of the above technical solution: Start the third motor 40, drive the turntable 42 to rotate, drive the first slider 44 to slide in the rotating rod 43, drive the rotating rod 43 to swing reciprocally with its lower end as the fulcrum, drive the second slider 45 to slide in the rotating rod 43, drive the push plate 47 to slide reciprocally in the U-shaped groove 46. The push plate 47 pushes the dirt particles in the U-shaped groove 46 to both ends. The dirt particles enter the collection box 51 through the slag discharge port 50. The dirt particles fall on the filter screen 52. The water in the dirt particles further falls into the water storage tank 53. The water in the water storage tank 53 enters the liquid storage chamber through the third water guide pipe 54. A one-way valve is arranged in the middle of the third water guide pipe 54 to prevent the water in the water storage tank 53 from flowing back into the liquid storage chamber. The door panel 55 on the side of the collection box 51 can be opened to facilitate removing the dirt particles on the filter screen 52. The filter screen 52 can be pulled out from the collection box 51 for easy cleaning or replacement.

[0067] It can be understood that the present invention is described through some embodiments. As is known to those skilled in the art, without departing from the spirit and scope of the present invention, various changes or equivalent replacements can be made to these features and embodiments. Additionally, under the teaching of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein. All embodiments falling within the scope of the claims of this application belong to the scope protected by the present invention.

Claims

1. Two-stage air flotation slag removal system for shale oil flowback fluid wastewater treatment, characterized in that, It includes an air flotation component. Wastewater enters the air flotation component through a wastewater inlet pipe. A dissolved air component is provided on the side of the air flotation component. The dissolved air component discharges the water dissolved with gas into the air flotation component through a connecting pipe (5). A scum scraping component is provided at the upper end of the air flotation component, and scum collection components are provided on both sides of the air flotation component.

2. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 1, wherein The air flotation component includes an air flotation tank (9). A first guide plate (10) and a second guide plate (11) are arranged in parallel in the air flotation tank (9). The first guide plate (10) and the second guide plate (11) divide the inside of the air flotation tank (9) into a primary air flotation chamber and a secondary air flotation chamber. There is a gap between the first guide plate (10) and the bottom of the air flotation tank (9). Diffusion plates (7) are provided in both the primary air flotation chamber and the secondary air flotation chamber. The dissolved air component is communicated with the diffusion plates (7) respectively through two connecting pipes (5). Mesh holes (8) are provided on both the flat surface and the inclined surface of the diffusion plate (7).

3. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 2, wherein, The wastewater inlet pipe includes a first wastewater inlet pipe (12) and a second wastewater inlet pipe (13). The first wastewater inlet pipe (12) and the second wastewater inlet pipe (13) are fixedly connected through a thickened pipe (14).

4. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 3, wherein A protective cover (56) is installed on the top of the air flotation tank (9). Two air outlet holes (57) are provided on the protective cover (56). The second wastewater inlet pipe (13) passes through the protective cover (56), and its end is located above the diffusion plate (7) in the primary air flotation chamber.

5. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 4, characterized in that, The dissolved air component includes an air inlet pipe (1). An air pump (2) is provided in the middle of the air inlet pipe (1). The lower end of the air inlet pipe (1) is connected with a diffusion column (3). The diffusion column (3) is located in a dissolved air tank (4). The dissolved air tank (4) is communicated with two diffusion plates (7) respectively through two connecting pipes (5). A control valve (6) is provided on the connecting pipe (5). The dissolved air tank (4) is communicated with the secondary air flotation chamber through a first water guide pipe (15). A first water pump (16) is provided in the middle of the first water guide pipe (15). The secondary air flotation chamber is communicated with the outside through a drain pipe (17). A ball valve is provided in the drain pipe (17).

6. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 5, characterized in that, The scum scraping component includes a first motor (18). The first motor (18) is fixed on the outer wall of the air flotation tank (9). The output end of the first motor (18) is connected with a first rotating shaft (19). The first rotating shaft (19) is in transmission cooperation connection with a first belt (20). The first belts (20) located on the upper and lower sides of the first rotating shaft (19) are respectively fixedly connected with two connecting blocks (21). The connecting blocks (21) are fixedly connected with a support plate (22). The support plate (22) is rotatably connected with a scraper (23). A baffle (24) is provided at the lower end of the support plate (22). The scraper (23) is fixedly connected with a gear shaft (25). The gear shaft (25) is in gear meshing transmission with a rack block (26). The rack block (26) is slidably connected with the air flotation tank (9). The rack block (26) is in threaded connection with a fastening screw (27). The front end of the fastening screw (27) abuts against the outer wall of the air flotation tank (9).

7. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 6, wherein The scum collection component includes a housing (28), the housing (28) is fixedly connected to the second motor (29), the output end of the second motor (29) is connected to the second rotating shaft (30), the second rotating shaft (30) is in transmission connection with the third rotating shaft (32) through the second belt (31), both the second rotating shaft (30) and the third rotating shaft (32) are in transmission connection with the mesh conveyor belt (38), the third rotating shaft (32) is fixedly connected to the first gear (33), the first gear (33) is in gear meshing transmission with the second gear (34), the second gear (34) is in gear meshing transmission with the third gear (35), the second gear (34) is fixedly connected to the first rolling brush (36), the third gear (35) is fixedly connected to the second rolling brush (37), and the first rolling brush (36) and the second rolling brush (37) rotate on the inner and outer sides of the mesh conveyor belt (38) respectively.

8. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 7, wherein, A partition (39) is fixedly arranged in the housing (28), the outer wall of the air flotation tank (9), the inner wall of the housing (28) and the partition (39) enclose a liquid storage chamber, the liquid storage chamber is communicated with one end of the second water guide pipe (48), the other end of the second water guide pipe (48) is fixedly arranged on the thickened pipe (14), a second water pump (49) is arranged in the middle of the second water guide pipe (48), the upper end of the partition (39) abuts against the lower side of the mesh conveyor belt (38), and a U-shaped groove (46) is fixedly arranged on the side surface of the partition (39).

9. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 8, characterized in that, A support frame (41) is fixedly arranged in the housing (28), the support frame (41) is fixedly connected to the third motor (40), the output end of the third motor (40) is connected to the turntable (42), the support frame (41) is rotatably connected to the lower end of the rotating rod (43), the rotating rod (43) is slidably connected to the first slider (44), the first slider (44) is rotatably connected to the small cylinder on the turntable (42), the rotating rod (43) is slidably connected to the second slider (45), the second slider (45) is rotatably connected to the push plate (47), and the push plate (47) slides in the U-shaped groove (46).

10. The two-stage air flotation slag removal system for shale oil flowback wastewater treatment according to claim 9, characterized in that, Discharge ports (50) are arranged on both sides of the housing (28), both discharge ports (50) are communicated with the U-shaped groove (46), collection boxes (51) are arranged on both sides of the housing (28), a filter screen (52) is arranged in the collection box (51), a water storage tank (53) is arranged at the lower end of the filter screen (52), the water storage tank (53) is communicated with the liquid storage chamber through the third water guide pipe (54), a one-way valve is arranged in the middle of the third water guide pipe (54), and a door panel (55) is arranged on the side surface of the collection box (51).

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