Flotation device for sewage treatment

Abstract

The invention discloses a flotation device for sewage treatment, and belongs to the technical field of sewage treatment equipment. The flotation device comprises a flotation tank, a dissolved air water release area is arranged on the side, close to a water inlet, in the flotation tank, and a scum area is arranged on the top of the flotation tank; the microbubble air-dissolved water generation system comprises a first release branch and a second release branch, and the outlet end of the first release branch extends into the air-dissolved water release area; the outlet end of the second release branch is positioned on one side, close to the water inlet of the flotation tank, of the scum area; the scum conveyor is located on the side, far away from the water inlet of the flotation tank, of the scum area and comprises an inclined lifting section, one end of the inclined lifting section extends into the scum area, the other end of the inclined lifting section is obliquely arranged upwards in the direction far away from the second release branch, and the scum is released by the dissolved air water released by the outlet end of the second release branch under the pushing action of the dissolved air water released by the outlet end of the second release branch. And scum in the scum area moves towards one side where the scum conveyor is located. According to the flotation device, the scum is lifted, so that the scum is taken away from the scum area.

Description

Technical Field

[0001] The present invention relates to the technical field of sewage treatment equipment, and more particularly to a flotation device for sewage treatment. Background Art

[0002] Flotation is one of the solid-liquid separation technologies widely used in sewage treatment. It produces micro-bubbles that attach to suspended matter, reducing the density of the suspended matter and causing it to float to the liquid surface, thereby achieving the effect of solid-liquid separation.

[0003] Common flotation devices for sewage treatment generally include a dosing mechanism for adding flocculants and coagulants, a generator for generating dissolved air water, and a scraper for scraping away scum. Existing scrapers are typically driven by chains or belts. Scrapers are evenly spaced along the conveying direction on the chain or belt. The scrapers extend into the scum layer and, driven by a motor, move within the layer, pushing the scum from one side of the layer to a scum collection area located near the other side. For example, Chinese patent application publication number CN210885400U discloses a flotation device for sewage treatment, which specifically includes a flotation tank, a dissolved air device, and a scraper. The flotation tank is sequentially arranged, from left to right, with an inlet dosing area, a dissolved air water area, an air flotation area, and a clear water area. The scraper is located above the air flotation area. The scraper device in this application utilizes evenly spaced scrapers on a chain or belt.

[0004] Existing scraper machines usually have the following problems: (1) The scraper extends into the scum area. Since the scraper is generally driven by a chain or belt, it is inevitable that it will vibrate during the scraping process, which can easily cause the scum layer floating on the water surface to vibrate, and then easily cause the bubbles on the surface of the suspended matter to detach, resulting in the density of the suspended matter increasing and sinking to the bottom; in addition, the scraping distance of the existing scraper machine is generally the distance between the two sides of the scum area, and the running distance of the scraper in the scum area is relatively long, so its vibration has a greater adverse effect on the scum layer; (2) The existing scraper machine has a large moving stroke, which causes it to occupy a large area. The area is large and the equipment cost is high; (3) the multiple scrapers distributed at intervals in the scraper are successively extended into the slag area to scrape the slag. This scraping method is periodic, and the slag is discharged discontinuously, resulting in uneven thickness of the slag layer; (4) the height at which the bottom end of the scraper is extended into the slag area is generally fixed, so the scraping thickness is also relatively fixed, which is not convenient for adapting to the scene of different slag layer thickness in the slag area in the actual process; (5) during the scraping process, the slag moves toward the slag collection area with the scraper, and the area between the two ends of the scraper along the width direction of the flotation tank and the two inner walls of the flotation tank is easy to be not scraped thoroughly enough. Summary of the Invention

[0005] 1. Technical problems to be solved

[0006] The present invention provides a flotation device for existing sewage treatment. This solution solves at least one technical problem described in the background art of the scraper in the existing flotation device by optimizing the design of the branch for releasing dissolved air water of the micro-bubble dissolved air water generating system and the arrangement of the scum conveyor.

[0007] 2. Technical solutions adopted

[0008] The present invention provides a flotation device for sewage treatment, comprising: a flotation tank, wherein a dissolved air water release zone is provided on one side of the flotation tank near its water inlet, and a scum zone is formed on the top of the flotation tank during flotation; a micro-bubble dissolved air water generating system, wherein the micro-bubble dissolved air water generating system comprises a first release branch and a second release branch, wherein the outlet end of the first release branch extends into the dissolved air water release zone; the outlet end of the second release branch is located on a side of the scum zone near the flotation tank water inlet; and a scum conveyor, wherein the scum conveyor is located on a side of the scum zone away from the flotation tank water inlet, and comprises an inclined lifting section, wherein one end of the inclined lifting section extends into the scum zone, and the other end is inclined upward in a direction away from the second release branch. Under the pushing action of the dissolved air water released at the outlet end of the second release branch, the scum in the scum zone moves toward the side where the scum conveyor is located.

[0009] Furthermore, the outlet end of the second release branch is provided with an air outlet pipe connected thereto, the air outlet pipe extends along the width direction of the flotation tank, and is provided with a long strip air outlet belt opening toward the side where the slag conveyor is located or a plurality of air outlet holes distributed at intervals.

[0010] Furthermore, the inclined lifting section has an inclination angle of 15 to 30 degrees with respect to the horizontal direction; and a scum collecting area is further provided below one end of the inclined lifting section away from the scum area.

[0011] Furthermore, the dissolved air and water release zone is located at the bottom of the flotation tank. The bottom of the flotation tank is also provided with a sedimentation zone located on the side of the dissolved air and water release zone close to the scum conveyor. The flotation tank and the sedimentation zone are separated by a partition; and are connected through the scum zone.

[0012] Furthermore, the sedimentation area includes an inclined tube sedimentation area and a sedimentation tank arranged from top to bottom, and the bottom of the sedimentation tank constitutes a sludge collection area; the inclined tube sedimentation area includes a first inclined tube sedimentation area and a second inclined tube sedimentation area located at the same horizontal height; the inclination directions of the first inclined tube sedimentation area and the second inclined tube sedimentation area are opposite, and the lower parts of the adjacent ends form a blind spot for sewage falling.

[0013] Furthermore, the micro-bubble dissolved air water generating system includes a water storage tank and a water collecting pipe, one end of the water collecting pipe is located inside the water storage tank, and the other end extends into the upper part of the sedimentation tank. The water collecting pipe includes a first water collecting section, a second water collecting section and a non-water collecting section that are coaxial and connected in sequence. The second water collecting section is located directly below the blind spot where sewage falls; the density of water collecting holes opened in the second water collecting section is greater than that in the first water collecting section and the non-water collecting section.

[0014] Furthermore, the first inclined tube sedimentation zone is arranged close to the dissolved air and water release zone, the second inclined tube sedimentation zone is arranged close to the slag conveyor and is located below the inclined lifting section, the size of the first inclined tube sedimentation zone along the length direction of the flotation tank is larger than the size of the second inclined tube sedimentation zone; the non-water collection section is located directly below the lower end of the second inclined tube sedimentation zone; the density of water collection holes opened in the first water collection section is greater than that in the non-water collection section.

[0015] Furthermore, the water storage tank is arranged close to the second inclined tube sedimentation area, and the bottom of the sludge collection area is arranged to be inclined downward in the direction close to the water storage tank.

[0016] Furthermore, the outlet end of the first release branch is provided with a plurality of first dissolved air water releasers connected thereto, and the plurality of first dissolved air water releasers are spaced apart along the width direction of the flotation tank and are located directly above the water distribution plate in the dissolved air water release area; the density of water distribution holes opened in the area of ​​the water distribution plate directly below two adjacent first dissolved air water releasers is greater than the density in other areas.

[0017] Furthermore, the flotation tank also includes a coagulation reaction zone, a flocculation reaction zone and a water distribution zone which are connected in sequence, and the water inlet of the dissolved air water release zone is connected to the water outlet of the water distribution zone; the coagulant dosing system is used to provide coagulant to the coagulation reaction zone, and the flocculant dosing system is used to provide flocculant to the flocculation reaction zone; and / or an inclined platform is provided below the inclined lifting section and is spaced apart from it, and the inclined lifting section has the same inclination angle as the inclined platform.

[0018] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0019] (1) The present invention optimizes the design of the branch for releasing dissolved air water from the microbubble dissolved air water generating system and the arrangement of the slag conveyor. Specifically, a second release branch is added to the microbubble dissolved air water generating system, and the second release branch releases dissolved air water toward the slag area, which is used to push the slag in the slag area to move toward the side where the slag conveyor is located; the bottom end of the slag conveyor extends into the slag conveyor, which is similar to the existing elevator, and it drives the slag to be lifted in the direction away from the slag area, thereby separating the slag from the slag area.

[0020] (2) The present invention further optimizes the design of the water inlet of the water collecting pipe in the microbubble dissolved air water generating system. Specifically, the inclined pipes in the first inclined pipe settling zone and the second inclined pipe settling zone are inclined in opposite directions, forming a blind area for sewage falling at the lower part of the adjacent ends of the two. The second water collecting section with more water collecting holes in the water collecting pipe is located directly below the blind area for sewage falling. The settling trajectory of the sewage settling tank is far away from the second water collecting section, which has little effect on the disturbance of the settled sewage in the area where the second water collecting section is located. This not only improves the speed and amount of water entering through the second water collecting section, but also helps to reduce the sludge content of the sewage in the water inlet collecting pipe.

[0021] (3) The present invention further optimizes the design of the dissolved air water release area. Specifically, the density of water distribution holes in the area directly below the two adjacent first dissolved air water releasers in the water distribution plate is greater than the density in the remaining areas. The dissolved air water release density in the area between the two adjacent first dissolved air water releasers is greater, and accordingly more water distribution holes are provided to improve the uniformity of the mixing of dissolved air water and sewage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the main structure of a flotation device for sewage treatment according to an embodiment of the present invention.

[0023] Figure 2 This is a schematic top view of the structure of a flotation device for sewage treatment according to an embodiment of the present invention.

[0024] Figure 3 This is a left-side structural schematic diagram of a flotation device for sewage treatment according to an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram of the three-dimensional structure of the second dissolved air water releaser in the flotation device for sewage treatment according to an embodiment of the present invention.

[0026] Figure 5 It is a schematic diagram of the three-dimensional structure of the water collecting pipe in the flotation device for sewage treatment according to an embodiment of the present invention.

[0027] Figure 6 It is a schematic plan view of the structure of a water collecting pipe in a flotation device for sewage treatment according to an embodiment of the present invention.

[0028] Figure 7 It is a schematic plan view of the partial structure of a sludge conveying and concentrating machine in a flotation device for sewage treatment according to an embodiment of the present invention.

[0029] Figure 8 for Figure 7 A magnified schematic diagram of the local structure.

[0030] Description of labels:

[0031] 1. Flotation tank; 101. Coagulation reaction zone; 111. First agitator; 112. First water inlet; 113. First dosing port; 102. Flocculation reaction zone; 121. Second agitator; 122. Second dosing port; 103. Water distribution zone; 104. Dissolved air and water release zone; 141. Water distribution plate; 142. Water distribution holes; 105. Scum zone; 106. Sludge collection zone; 107. First inclined tube settling zone; 108. Second inclined tube settling zone; 109. Scum collection zone; 191. Scum discharge port;

[0032] 2. Coagulant dosing system;

[0033] 3. Flocculant dosing system;

[0034] 4. Slag conveyor; 401. Inclined lifting section; 402. Inclined platform;

[0035] 5. Microbubble dissolved air water generating system; 501. First release branch; 511. First dissolved air water releaser; 502. Second release branch; 521. Air outlet pipe; 503. Liquid level regulator; 504. Water collection pipe; 541. First water collection section; 542. Second water collection section; 543. Non-water collection section; 544. Water collection hole; 505. Water storage tank; 551. Water storage tank outlet; 506. Air compressor; 507. Bubble generating tank; 571. Spiral mixing guide trough; 508. Water inlet pump; 509. Liquid level controller;

[0036] 6. Sludge conveying concentrator; 601. Sludge concentrating motor; 602. Sludge back pressure plate; 603. Concentrating section housing; 604. Screw shaft;

[0037] 7. Intelligent control system. DETAILED DESCRIPTION

[0038] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0039] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for understanding and reading by those familiar with this technology. They are not used to limit the conditions for implementation of the present invention and therefore have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, terms such as "upper", "lower", "left", "right", and "middle" quoted in this specification are only for the convenience of description and are not used to limit the scope of implementation. Changes or adjustments in their relative relationships should also be considered as the scope of implementation of the present invention without substantially changing the technical content.

[0040] The flotation tank 1 is generally a rectangular box structure. For the following embodiments and directions, please refer to Figure 1 The viewing angle shown, Figure 1 The direction of the line connecting the left and right sides is called the length direction of the flotation tank 1, that is, the horizontal direction of the line connecting the outlet end of the second release branch 502 to the slag conveyor 4 is called the length direction of the flotation tank 1. Figure 2 The direction of the line connecting the upper and lower sides is called the width direction of the flotation cell 1 , that is, the horizontal direction perpendicular to the above-mentioned length direction is called the width direction of the flotation cell 1 .

[0041] This embodiment provides a flotation device for sewage treatment, referring to Figure 1 、 Figure 2 、 Figure 3 As shown, the flotation device includes a flotation tank 1; a dissolved air water release area 104 is provided on one side of the flotation tank 1 near its water inlet, and a scum area 105 is formed on the top of the flotation tank 1 during the flotation process; a micro-bubble dissolved air water generating system 5, the micro-bubble dissolved air water generating system 5 includes a first release branch 501 and a second release branch 502, the outlet end of the first release branch 501 extends into the dissolved air water release area 104; the outlet end of the second release branch 502 is located in the scum area 105 near the flotation tank 1. One side of the water inlet of the selection tank 1; and the slag conveyor 4, the slag conveyor 4 is located on the side of the slag area 105 away from the water inlet of the flotation tank 1, the slag conveyor 4 includes an inclined lifting section 401, one end of the inclined lifting section 401 extends into the slag area 105, and the other end is inclined upward in a direction away from the second release branch 502. Under the push of the dissolved air water released at the outlet end of the second release branch 502, the slag in the slag area 105 moves toward the side where the slag conveyor 4 is located.

[0042] The present invention adds a second release branch 502 to the microbubble dissolved air water generating system 5, and the outlet end of the second release branch 502 is located on the side of the scum area 105 close to the water inlet of the flotation tank 1; the second release branch 502 releases dissolved air toward the scum area 105, which is used to push the scum in the scum area 105 toward the side where the scum conveyor 4 is located; the bottom end of the inclined lifting section 401 in the scum conveyor 4 extends into the scum conveyor 4, and the inclined lifting section 401 is similar to an existing elevator. It drives the scum to move upward in a direction away from the second release branch 502, that is, lifts it in a direction away from the outlet end of the second release branch 502, thereby separating the scum from the scum area 105.

[0043] The present invention can achieve the following technical effects: a. The traditional scraper has a long movement route when extending into the scum area, while the present invention only needs to extend the bottom end of the scum conveyor 4 into one side of the scum area 105. The contact area between the scum conveyor 4 and the scum area 105 is small, so its shaking has little effect on the scum area, and it is not easy to cause the bubbles on the surface of the suspended matter to separate; b. The present invention only needs to use the scum conveyor 4 to lift the scum for a distance so that it no longer falls into the scum area 105, and does not need to move from one side of the scum area 105 to the other side. Therefore, the footprint of the scum conveyor 4 along the length direction of the flotation tank 1 is greatly reduced compared with the traditional scraper scraper; c. The scraping method for lifting the scum is continuous scraping, and the traditional scraper scraping is discontinuous periodic scraping. Compared with the traditional scraping method, the scum is discharged relatively continuously, maintaining the thickness of the scum layer in the scum area 105 relatively uniform; d. The bottom end of the scum conveyor 4 is extended into the scum area 105 to separate the scum from the scum area 105 in a lifting manner. This separation method does not require the setting of a scraper, is not limited by the thickness of the scum layer, and can adapt to the situation where the thickness of the scum layer is different in different places; e. The dissolved air and water released by the second release branch 502 of the present invention pushes the scum in the scum area 105 to continuously move toward the scum conveyor 4, and it is not easy to have dead corners for scraping, so the scraping is more thorough.

[0044] Preferably, the bottom end of the slag conveyor 4 extends into the bottom of the slag area 105 .

[0045] The micro-bubble dissolved air water generating system 5 is used to generate and deliver micro-bubble dissolved air water. Figure 1 、 Figure 2 As shown, the micro-bubble dissolved air water generating system 5 includes a water inlet pump 508, an air compressor 506, a bubble generating tank 507, and a water storage tank 505. The water inlet pump 508 pumps water from the water storage tank 505 into the bubble generating tank 507. The gas inlet in the bubble generating tank 507 is connected to the output end of the air compressor 506. Specifically, there is a valve in the connecting pipe between the water inlet pump 508 and the bubble generating tank 507. More specifically, a spiral mixing guide groove 571 and a liquid level controller 509 are further provided inside the bubble generating tank 507. After the water and air are fully mixed in the spiral mixing guide groove 571 inside the bubble generating tank 507, the liquid level controller 509 is used to control the height of the liquid level in the bubble generating tank 507, thereby controlling the ratio of air to water in the bubble generating tank 507. The bubble generating tank 507 outputs the dissolved air water to the first release branch 501 and the second release branch 502.

[0046] Specifically, refer to Figure 1 、 Figure 4As shown, the outlet end of the second release branch 502 is provided with an air outlet pipe 521 connected thereto. The air outlet pipe 521 extends along the width of the flotation cell 1 and is provided with a long strip of air outlet belt or a plurality of spaced air outlet holes that open toward the side where the slag conveyor 4 is located. The gap of the long strip of air outlet belt along the height of the flotation cell 1 is preferably 4 to 6 mm, and the diameter of the circular air outlet holes is preferably 8 to 12 mm.

[0047] The present invention makes full use of the micro-bubble dissolved air water generating system 5 required by the existing flotation device, and adds a second release branch 502 in the dissolved air water outlet channel of the micro-bubble dissolved air water generating system 5, without the need to add an additional micro-bubble dissolved air water generating system.

[0048] More specifically, the inclined lifting section 401 is inclined at an angle of 15 to 30 degrees to the horizontal direction. A scum collection area 109 is provided below the end of the inclined lifting section 401 away from the scum area 105. The scum moves to the highest point along the inclined lifting section 401 and then falls into the scum collection area 109.

[0049] The scum collecting area 109 is connected to the scum discharge port 191 through a pipeline, so as to discharge the scum to the outside of the flotation tank 1 .

[0050] As an extension, an inclined platform 402 is spaced below the inclined lifting section 401. The inclined lifting section 401 and the inclined platform 402 have the same inclination angle. The inclined platform 402 is used to scrape off scum carried by the inclined lifting section 401 during its return journey and to divert sewage falling through the inclined lifting section 401.

[0051] The scum moves along the inclined lifting section 401 from its bottom to its top. As the inclined lifting section 401 returns, the scum falls from the inclined lifting section 401 to the scum collection area 109. At this point, if there is any scum adhering to the inclined lifting section 401, the scum contacts the inclined platform 402, thereby scraping the scum carried by the inclined lifting section 401. Simultaneously, the scum mixed with sewage moves upward along the inclined lifting section 401. During the upward movement, the sewage falls from the inclined lifting section 401 to the inclined platform 402 due to gravity, and then flows back into the scum area 105.

[0052] In some embodiments, the dissolved air and water release zone 104 is located at the bottom of the flotation tank 1. The bottom of the flotation tank 1 is also provided with a sedimentation zone located on the side of the dissolved air and water release zone 104 close to the scum conveyor 4. The flotation tank 1 and the sedimentation zone are separated into two areas that are not directly connected by a partition; and are connected through the scum zone 105.

[0053] As a further preferred implementation of the above embodiment, the sedimentation area includes an inclined tube sedimentation area and a sedimentation tank arranged from top to bottom in accordance with the law, and the bottom of the sedimentation tank constitutes a sludge collection area 106; the inclined tube sedimentation area includes a first inclined tube sedimentation area 107 and a second inclined tube sedimentation area 108 located at the same horizontal height; the first inclined tube sedimentation area 107 and the second inclined tube sedimentation area 108 are inclined in opposite directions, and the lower parts of the adjacent ends form a blind spot for sewage falling.

[0054] Specifically, the first inclined tube settling area 107 and the second inclined tube settling area 108 each include a plurality of inclined tubes with the same inclination angle, and the inclined tubes in the first inclined tube settling area 107 and the inclined tubes in the second inclined tube settling area 108 are inclined in opposite directions. Figure 1 As shown, sewage flows from the inclined tubes in the first inclined tube settling zone 107 along the upper right to the lower left, and from the inclined tubes in the second inclined tube settling zone 108 along the upper left to the lower right. The top ends of the first inclined tube settling zone 107 and the second inclined tube settling zone 108 are in contact, and there is no sewage drop channel between them. Sewage can only settle into the sedimentation tank through the inclined tubes in the first inclined tube settling zone 107 and the second inclined tube settling zone 108. The bottom ends of the first inclined tube settling zone 107 and the second inclined tube settling zone 108 are separated from each other, forming a fan-shaped blind spot for sewage drop.

[0055] As a preferred embodiment of the microbubble dissolved air water generating system 5, the microbubble dissolved air water generating system 5 includes a water storage tank 505 and a water collecting pipe 504. One end of the water collecting pipe 504 is located inside the water storage tank 505, and the other end extends into the upper part of the sedimentation tank. The water collecting pipe 504 includes a first water collecting section 541, a second water collecting section 542 and a non-water collecting section 543 that are coaxial and connected in sequence. The second water collecting section 542 is located directly below the blind spot where sewage falls; the density of the water collecting holes (544) opened in the second water collecting section (542) is greater than that in the first water collecting section (541) and the non-water collecting section (543).

[0056] As can be seen from the above, the interior of the water storage tank 505 is connected to the upper part of the sedimentation tank through the water collecting pipe 504, and the water inside the sedimentation tank enters the water storage tank 505 through the water collecting pipe 504. Water is taken from the sedimentation tank through the water collecting pipe 504, thereby saving water resources.

[0057] From the trajectory of the sewage falling through the first inclined tube sedimentation area 107 and the second inclined tube sedimentation area 108, it can be seen that the falling trajectory of the sewage is far away from the second water collection section 542, so the disturbance effect on the settled sewage in the area where the second water collection section 542 is located is relatively small. The sewage in the area where the second water collection section 542 is located is mainly sewage after sedimentation, and its sludge content is relatively low. Therefore, more water collection holes are opened in the second water collection section 542, that is, the density of the water collection holes 544 opened in the second water collection section 542 is greater than that of the first water collection section 541 and the non-water collection section 543, which can increase the speed and amount of water inlet through the second water collection section 542, thereby improving the clarity of the sewage in the water storage tank 505, and reducing the adverse effect of the dynamic sedimentation of sewage in the sedimentation tank on the water inlet of the water storage tank 505.

[0058] As an expansion solution, a water tank outlet 551 is provided on one side of the water tank 505, and a liquid level regulator 504 connected to the water tank outlet 551 is provided inside the water tank 505. The liquid level regulator 504 is used to control the water level height of the water tank 505. When the water level inside the water tank 505 exceeds the set value, it is discharged through the water tank outlet 551.

[0059] As a further implementation method, refer to Figure 1 、 Figure 5 As shown, the first inclined tube settling zone 107 is arranged close to the dissolved air and water release zone 104, the second inclined tube settling zone 108 is located below the inclined lifting section 401, and the size of the first inclined tube settling zone 107 along the length direction of the flotation tank 1 is larger than the size of the second inclined tube settling zone 108; the non-water collection section 543 is located directly below the lower end of the second inclined tube settling zone 108, and the density of the water collection holes 544 opened in the first water collection section 541 is greater than that in the non-water collection section 543.

[0060] From the above description, it can be seen that the first water collecting section 541 is located below the first inclined tube settling area 107. Preferably, there is a gap between the inner side wall of the settling tank and the end of the first water collecting section 541 along the axial direction thereof.

[0061] Further preferably, the non-water collection section 543 does not have a water collection hole 544. As the scum conveyor 4 is lifted, the sewage mixed with the scum falls into the scum layer above the second inclined tube settling zone 108. The sewage mixed with the scum descends through the second inclined tube settling zone 108. Therefore, the sewage obtained by settling in the second inclined tube settling zone 108 contains relatively large amounts of impurities. Therefore, the non-water collection section 543 below the second inclined tube settling zone 108 does not have a water collection hole 544.

[0062] refer to Figure 6 As shown, the water collection holes 544 are symmetrically distributed on both sides of the vertical symmetry axis of the water collection pipe 504, and are inclined downward relative to the horizontal symmetry axis of the water collection pipe 504, and the angle between the center line and the vertical direction is between 30 and 45 degrees.

[0063] More preferably, the water storage tank 505 is arranged near the second inclined tube sedimentation area 108, and the bottom of the sludge collection area 106 is arranged to be inclined downward in the direction close to the water storage tank 505.

[0064] As a further preference for any of the above embodiments, the outlet end of the first release branch 501 is provided with a plurality of first dissolved air water releasers 501 connected thereto, and the plurality of first dissolved air water releasers 501 are spaced apart along the width direction of the flotation tank 1 and are located directly above the water distribution plate 141 in the dissolved air water release area 104; the density of the water distribution holes 142 in the area of ​​the water distribution plate 141 directly below two adjacent first dissolved air water releasers 501 is greater than the density in the remaining areas.

[0065] It should be noted that the first dissolved air water releaser 501 generally includes a plurality of dissolved air water release ports spaced apart along the circumferential direction. Figure 1 As shown, a single first dissolved air water releaser 501 is provided with eight dissolved air water release ports spaced evenly along the circumference. In the interval between two adjacent first dissolved air water releasers 501, the density of the dissolved air water release ports is greater than the density in other areas of the dissolved air water release zone 104. Accordingly, the dissolved air water release density in the area between two adjacent first dissolved air water releasers 501 is greater. Therefore, more water distribution holes 142 are provided in this area directly opposite the water distribution plate 141. The density of the water distribution holes 142 in different areas of the water distribution plate 141 is adjusted based on the density of dissolved air water released from the first dissolved air water releaser 501 to improve the uniformity of mixing of dissolved air water and sewage.

[0066] In order to improve the effluent quality of the sedimentation tank, refer to Figure 7 、 Figure 8 As shown, a sludge conveying and concentrating machine 6 is installed at the bottom of the sludge collection area 106. The sludge conveying and concentrating machine 6 includes a screw shaft 604 and spiral blades arranged around the screw shaft 604. The inlet end of the concentrating section housing 603 is connected to the outlet end of the sludge collection area 106. One end of the screw shaft 604 is located inside the sludge collection area 106, and the other end extends into the concentrating section housing 603. A sludge backpressure plate 602 is mounted on the outside of this end. The distance between the sludge backpressure plate 602 and the outlet end of the concentrating section housing 603 is adjustable. The output end of the sludge concentrating motor 601 is connected to the screw shaft 604 via a reducer and a coupling. The sludge concentrating motor 601 drives the screw shaft 604 to rotate. By installing the sludge conveying and concentrating machine 6, the sludge in the sludge collection area 106 is concentrated and discharged.

[0067] Among them, the sludge back pressure plate 602 and the discharge end of the concentration stage shell 603 constitute a sludge gap outlet. By adjusting the distance between the sludge back pressure plate 602 and the discharge end of the concentration stage shell 603, the thickness of the sludge cake after sludge compression is controlled, and then the moisture content of the sludge cake is controlled.

[0068] Preferably, along the direction from one end of the screw shaft 604 located inside the sludge collection area 106 to the other end thereof, the shaft diameter of the screw shaft 604 gradually increases and is tilted upward by 2 to 5 degrees, and the pitch of the spiral blades gradually decreases, so that the volume of the spiral sealing cavity formed between adjacent spiral blades gradually decreases, and the moisture carried in the sludge is continuously squeezed out, while facilitating the falling of the moisture carried in the sludge.

[0069] Specifically, the flotation tank 1 also includes a coagulation reaction zone 101, a flocculation reaction zone 102 and a water distribution zone 103 which are connected in sequence. The water inlet of the dissolved air water release zone 104 and the water outlet of the water distribution zone 103 are connected through a water distribution plate 141; the coagulant dosing system 2 is used to provide coagulant to the coagulation reaction zone 101, and the flocculant dosing system 3 is used to provide flocculant to the flocculation reaction zone 102.

[0070] The flotation tank 1 can be divided into corresponding functional areas by partitions to form a coagulation reaction area 101, a flocculation reaction area 102 and a water distribution area 103, and the flow paths between different functional areas are defined by pipes.

[0071] The coagulation reaction zone 101 is provided with a first water inlet 112 for sewage to enter and a first dosing port 113 for adding coagulant. In order to improve the mixing effect of the agent, a first stirrer 111 is provided inside the coagulation reaction zone 101.

[0072] The water inlet of the flocculation reaction zone 102 is connected to the water outlet of the coagulation reaction zone 101. The flocculation reaction zone 102 is provided with a second dosing port 122 for adding flocculation agents. In order to improve the mixing effect of the agents, a second stirrer 121 is provided inside the flocculation reaction zone 102.

[0073] The flotation device for sewage treatment is internally provided with an intelligent control system 7, which is used to control the orderly operation of the coagulation reaction zone 101, the flocculation reaction zone 102, the water distribution zone 103, the scum conveyor 4, the micro-bubble dissolved air water generating system 5 and the sludge conveying concentrator 6.

[0074] The specific process of sewage flotation by the flotation device for sewage treatment is as follows:

[0075] S1, sewage passes through the coagulation reaction zone 101, flocculation reaction zone 102, water distribution zone 103 in sequence and enters the dissolved air water release zone 104;

[0076] S2. The sewage meets the dissolved air released from the outlet of the first release branch 501 in the dissolved air release area 104. The dissolved air drives the scum in the sewage upward to the scum area 105.

[0077] S3, the outlet end of the second release branch 502 releases dissolved air and water to push the slag in the slag area 105 toward the side where the slag conveyor 4 is located;

[0078] S4, the scum conveyor 4 lifts the scum in the scum area 105 and drives it to move away from the scum area 105 to separate the scum from the scum area 105; the scum enters the scum collection area 109 and is then discharged to the outside of the flotation tank 1;

[0079] S5. The sewage enters the inclined tube settling area through the scum area 105. The sewage flows down to the settling tank through the inclined tube settling area. The sewage settles in the settling tank to the sludge collection area 106. The sludge conveying concentrator 6 conveys the sludge in the sludge collection area 106 to the outside of the flotation tank 1 and compresses it into a mud cake.

[0080] S6. The clean water in the sedimentation tank enters the water storage tank 505 in the micro-bubble dissolved air water generating system 5 through the water collecting pipe 504. Part of it is used as the raw material for the micro-bubble dissolved air water generating system 5 to generate dissolved air water, and the other part is discharged through the water storage tank outlet 551.

[0081] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by this and, without departing from the purpose of the present invention, designs a structure and embodiment similar to this technical solution without inventiveness, they shall fall within the scope of protection of the present invention.

Claims

1. A flotation device for sewage treatment, characterized in that: include: A flotation tank (1), wherein a dissolved air and water release area (104) is provided on one side of the flotation tank (1) near its water inlet, and a scum area (105) is formed on the top of the flotation tank (1) during the flotation process; A micro-bubble dissolved air water generating system (5) comprising a first release branch (501) and a second release branch (502), wherein the outlet end of the first release branch (501) extends into the dissolved air water release area (104); the outlet end of the second release branch (502) is located on a side of the scum area (105) close to the water inlet of the flotation tank (1); and A scum conveyor (4) is provided, the scum conveyor (4) being located on a side of the scum area (105) away from the water inlet of the flotation tank (1). The scum conveyor (4) comprises an inclined lifting section (401), one end of the inclined lifting section (401) extending into the scum area (105), and the other end of the inclined lifting section (401) being arranged to be inclined upward in a direction away from the second release branch (502). Under the driving action of dissolved air water released at the outlet end of the second release branch (502), the scum in the scum area (105) moves toward the side where the scum conveyor (4) is located.

2. The flotation device for sewage treatment according to claim 1, characterized in that: The outlet end of the second release branch (502) is provided with an air outlet pipe (521) connected thereto, the air outlet pipe (521) extending along the width direction of the flotation tank (1) and provided with a long strip air outlet belt or a plurality of air outlet holes distributed at intervals and opening toward the side where the slag conveyor (4) is located.

3. The flotation device for sewage treatment according to claim 1, characterized in that: The inclined lifting section (401) has an inclination angle of 15 to 30 degrees with respect to the horizontal direction; and a scum collecting area (109) is further provided below one end of the inclined lifting section (401) away from the scum area (105).

4. The flotation device for sewage treatment according to claim 3, characterized in that: The dissolved air and water release zone (104) is located at the bottom of the flotation tank (1). The bottom of the flotation tank (1) is also provided with a sedimentation zone located on the side of the dissolved air and water release zone (104) close to the scum conveyor (4). The flotation tank (1) and the sedimentation zone are separated by a partition and are connected through the scum zone (105).

5. The flotation device for sewage treatment according to claim 4, characterized in that: The settling area includes an inclined tube settling area and a settling tank arranged from top to bottom, and the bottom of the settling tank constitutes a sludge collection area (106); the inclined tube settling area includes a first inclined tube settling area (107) and a second inclined tube settling area (108) located at the same horizontal height; the first inclined tube settling area (107) and the second inclined tube settling area (108) are inclined in opposite directions, and the lower parts of adjacent ends form a sewage falling blind area.

6. The flotation device for sewage treatment according to claim 5, characterized in that: The micro-bubble dissolved air water generating system (5) comprises a water storage tank (505) and a water collecting pipe (504), one end of the water collecting pipe (504) is located inside the water storage tank (505), and the other end extends into the upper part of the sedimentation tank, the water collecting pipe (504) comprises a first water collecting section (541), a second water collecting section (542) and a non-water collecting section (543) which are coaxial and sequentially connected, the second water collecting section (542) being located directly below the blind spot where sewage falls; the density of the water collecting holes (544) provided in the second water collecting section (542) is greater than that in the first water collecting section (541) and the non-water collecting section (543).

7. The flotation device for sewage treatment according to claim 6, characterized in that: The first inclined tube settling area (107) is arranged close to the dissolved air and water release area (104), the second inclined tube settling area (108) is arranged close to the slag conveyor (4) and located below the inclined lifting section (401), the size of the first inclined tube settling area (107) along the length direction of the flotation tank (1) is larger than the size of the second inclined tube settling area (108); the non-water collection section (543) is located directly below the lower end of the second inclined tube settling area (108); the density of the water collection holes (544) opened in the first water collection section (541) is greater than that in the non-water collection section (543).

8. The flotation device for sewage treatment according to claim 7, characterized in that: The water storage tank (505) is arranged close to the second inclined tube sedimentation area (108), and the bottom of the sludge collection area (106) is arranged to be inclined downward in the direction close to the water storage tank (505).

9. The flotation device for sewage treatment according to any one of claims 1 to 8, characterized in that: The outlet end of the first release branch (501) is provided with a plurality of first dissolved air water releasers (501) in communication therewith. The plurality of first dissolved air water releasers (501) are spaced apart along the width direction of the flotation tank (1) and are located directly above the water distribution plate (141) in the dissolved air water release area (104). The density of the water distribution holes (142) in the area directly below two adjacent first dissolved air water releasers (501) in the water distribution plate (141) is greater than that in the remaining areas.

10. The flotation device for sewage treatment according to any one of claims 1 to 8, characterized in that: The flotation tank (1) further comprises a coagulation reaction zone (101), a flocculation reaction zone (102) and a water distribution zone (103) which are connected in sequence, and a water inlet of the dissolved air water release zone (104) is connected to a water outlet of the water distribution zone (103); a coagulant dosing system (2) is used to provide coagulant to the coagulation reaction zone (101), and a flocculant dosing system is used to provide flocculant to the flocculation reaction zone (102); And / or an inclined platform (402) is provided below the inclined lifting section (401) and spaced apart from the inclined lifting section (401), and the inclined lifting section (401) and the inclined platform (402) have the same inclination angle.

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