A flotation device for sewage treatment

Abstract

The application discloses a kind of sewage treatment with flotation device, belong to sewage treatment equipment technical field.The flotation device includes flotation tank, and the side of the inside of flotation tank close to its water inlet is equipped with dissolved air water release area, and the top of flotation tank is scum area;Micro-bubble dissolved air water generating system includes first release branch and second release branch, and the outlet end of first release branch is inserted into dissolved air water release area;The outlet end of second release branch is located in the side of scum area close to the water inlet of flotation tank;And the scum conveyor in the side of scum area away from the water inlet of flotation tank, and the scum conveyor includes inclined lifting section, and one end of inclined lifting section is inserted into scum area, and the other end is inclined upwardly and is arranged in the direction away from second release branch, under the impetus of dissolved air water released in the outlet end of second release branch, scum in scum area moves towards the side where scum conveyor is located.The flotation device brings scum away from scum area by the way of lifting scum.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sewage treatment equipment, more particularly to a flotation device for sewage treatment. BACKGROUND

[0002] Air flotation is one of the widely used solid-liquid separation technologies in sewage treatment. It makes the density of suspended solids decrease by attaching micro-bubbles produced to the suspended solids, and then makes the suspended solids float to the liquid surface to achieve the effect of solid-liquid separation.

[0003] The common flotation device for sewage treatment generally includes a dosing mechanism for dosing flocculants and coagulants, a generator for generating dissolved air water, and a slag scraper for scraping off the scum. The existing slag scraper generally adopts chain or belt drive, and evenly spaced scrapers are arranged on the chain or belt along the conveying direction. The scrapers extend into the scum layer and move in the scum layer under the drive of the motor, pushing the scum from one side of the scum layer to the scum collection area located near the other side of the scum layer. For example, the Chinese patent application with publication number CN210885400U discloses a flotation device for sewage treatment, which specifically includes a flotation tank, a dissolved air device, and a slag scraping device. The flotation tank is sequentially provided with a water inlet dosing area, a dissolved air water area, an air flotation area, and a clear water area from left to right. The slag scraping device is located at the upper part of the air flotation area. The slag scraping device in this application adopts the design of evenly spaced scrapers arranged on the chain or belt.

[0004] The existing slag scraper generally has the following problems: (1) The scrapers extend into the scum area. Since the scrapers are generally driven by chains or belts, they inevitably have a shaking problem during the scraping process, which easily causes the scum layer floating on the water surface to shake, and then easily causes the bubbles on the surface of the suspended solids to detach, resulting in an increase in the density of the suspended solids and a phenomenon of sinking to the bottom. In addition, the scraping distance of the existing scraper 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 the shaking has a greater adverse effect on the scum layer; (2) The moving stroke of the existing scraper is large, resulting in a large floor area and high equipment cost; (3) The multiple scrapers of the scraper are arranged at intervals and extend into the scum area in turn to scrape the scum. This scraping method is periodic, and there is a discontinuous situation of scum discharge, resulting in uneven thickness of the scum layer; (4) The height of the bottom end of the scraper extending into the scum area is generally fixed, so the scraping thickness is also relatively fixed, and it is not convenient to adapt to the scene of different thicknesses of the scum layer in the actual process; (5) During the scraping process, the area between the two ends of the scraper along the width direction of the flotation tank and the two inner side walls of the flotation tank is easily not scraped thoroughly. SUMMARY

[0005] 1. Technical problems to be solved

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

[0007] 2. Technical scheme adopted

[0008] The present application provides a flotation device for sewage treatment, which comprises: a flotation tank, a dissolved air water releasing area is arranged on one side of the flotation tank close to the water inlet, and a dregs area is formed on the top of the flotation tank during the flotation process; a micro-bubble dissolved air water generating system, the micro-bubble dissolved air water generating system comprises a first releasing branch and a second releasing branch, the outlet end of the first releasing branch extends into the dissolved air water releasing area; the outlet end of the second releasing branch is located on one side of the dregs area close to the water inlet of the flotation tank; and a dregs conveyor, the dregs conveyor is located on one side of the dregs area away from the water inlet of the flotation tank, the dregs conveyor comprises an inclined lifting section, one end of the inclined lifting section extends into the dregs area, and the other end is inclined upward away from the second releasing branch, under the pushing action of the dissolved air water released from the outlet end of the second releasing branch, the dregs in the dregs area moves towards the side where the dregs conveyor is located.

[0009] Further, the outlet end of the second releasing branch is provided with an air outlet pipe in communication therewith, the air outlet pipe extends along the width direction of the flotation tank, and is provided with a long strip-shaped air outlet belt or a plurality of air outlet holes spacedly distributed and opening towards the side where the dregs conveyor is located.

[0010] Further, the inclination angle of the inclined lifting section with the horizontal direction is 15-30°; and a dregs collecting area is further arranged below the end of the inclined lifting section away from the dregs area.

[0011] Further, the dissolved air water releasing area is located at the bottom of the flotation tank, the bottom of the flotation tank is further provided with a settling area located on the side of the dissolved air water releasing area close to the dregs conveyor, the flotation tank and the settling area are separated by a partition plate; and are in communication through the dregs area.

[0012] Further, the settling area comprises an inclined pipe settling area and a settling tank arranged from top to bottom, the bottom of the settling tank constitutes a sludge collecting area; the inclined pipe settling area comprises a first inclined pipe settling area and a second inclined pipe settling area located at the same horizontal level; the inclination directions of the first inclined pipe settling area and the second inclined pipe settling area are opposite, and the lower parts of the adjacent ends form a blind area for falling sewage.

[0013] Further, the micro-bubble dissolved air water generating system comprises a water storage tank and a water collecting pipe, one end of the water collecting pipe is located inside the water storage tank, the other end extends into the upper part of the sedimentation tank, the water collecting pipe comprises a first water collecting section, a second water collecting section and a non-water collecting section which are coaxial and sequentially connected, the second water collecting section is located directly below the blind area of the sewage falling; the density of the water collecting holes in the second water collecting section is greater than that in the first water collecting section and the non-water collecting section.

[0014] Further, the first inclined pipe settling zone is arranged close to the dissolved air water release zone, the second inclined pipe settling zone is arranged close to the dregs conveyor and below the inclined lifting section, the size of the first inclined pipe settling zone along the length direction of the flotation tank is greater than that of the second inclined pipe settling zone; the non-water collecting section is located directly below the lower end of the second inclined pipe settling zone; the density of the water collecting holes in the first water collecting section is greater than that in the non-water collecting section.

[0015] Further, the water storage tank is arranged close to the second inclined pipe settling zone, and the bottom of the sludge collecting zone is arranged to be inclined downward along the direction close to the water storage tank.

[0016] Further, the outlet end of the first release branch is provided with a plurality of first dissolved air water release devices which are in communication with the outlet end, the plurality of first dissolved air water release devices are distributed in the width direction of the flotation tank and are located directly above the water distribution plate in the dissolved air water release zone; the density of the water distribution holes in the area of the water distribution plate which is directly below the adjacent two first dissolved air water release devices is greater than that in the remaining areas.

[0017] Further, the flotation tank further comprises a coagulation reaction zone, a flocculation reaction zone and a water distribution zone which are sequentially connected, the water inlet of the dissolved air water release zone is in communication with the water outlet of the water distribution zone; the coagulant dosing system is used for providing coagulant for the coagulation reaction zone, the flocculant dosing system is used for providing flocculant for the flocculation reaction zone; and / or the inclined lifting section is provided with an inclined platform which is arranged in a spaced manner below the inclined lifting section, and the inclined angles of the inclined lifting section and the inclined platform are the same.

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

[0019] (1) The present application optimizes the arrangement mode of the branch of the micro-bubble dissolved air water generating system which releases dissolved air water and the dregs conveyor, specifically, a second release branch is added in the micro-bubble dissolved air water generating system, the second release branch releases dissolved air water towards the dregs area, and is used for driving the dregs in the dregs area to move towards the side where the dregs conveyor is located; the bottom end of the dregs conveyor extends into the dregs conveyor, and the dregs conveyor is similar to the existing lifting machine, which drives the dregs to be lifted in the direction away from the dregs area, so as to separate the dregs from the dregs area.

[0020] (2) The application further optimizes the water inlet of the water collecting pipe in the microbubble dissolved air water generating system, specifically, the inclined pipes of the first inclined pipe settling zone and the second inclined pipe settling zone are opposite in inclination direction, a sewage falling blind area is formed at the lower part of the adjacent ends of the two, the second water collecting section with a plurality of water collecting holes in the water collecting pipe is located directly below the sewage falling blind area, and the settling track of the sewage settling tank is away from the second water collecting section, so that the disturbance to the settled sewage in the area where the second water collecting section is located is small, the speed and the water inlet amount of the water inlet through the second water collecting section are improved, and the sludge content of the sewage in the water inlet water collecting pipe is reduced.

[0021] (3) The application further optimizes the dissolved air water releasing area, specifically, the density of the water distribution holes in the area directly below the adjacent two first dissolved air water releasers in the water distribution plate is greater than that in the remaining areas, the dissolved air water releasing density between the adjacent two first dissolved air water releasers is greater, and more water distribution holes are correspondingly arranged to improve the uniformity of the mixing of the dissolved air water and the sewage. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a front view structural schematic diagram of the flotation device for sewage treatment in the embodiment of the application.

[0023] Figure 2 It is a top view structural schematic diagram of the flotation device for sewage treatment in the embodiment of the application.

[0024] Figure 3 It is a left view structural schematic diagram of the flotation device for sewage treatment in the embodiment of the application.

[0025] Figure 4 It is a three-dimensional structural schematic diagram of the second dissolved air water releaser in the flotation device for sewage treatment in the embodiment of the application.

[0026] Figure 5 It is a three-dimensional structural schematic diagram of the water collecting pipe in the flotation device for sewage treatment in the embodiment of the application.

[0027] Figure 6 It is a plane structural schematic diagram of the water collecting pipe in the flotation device for sewage treatment in the embodiment of the application.

[0028] Figure 7 It is a plane schematic diagram of the local structure of the sludge conveying thickener in the flotation device for sewage treatment in the embodiment of the application.

[0029] Figure 8 It is a three-dimensional structural schematic diagram of the sludge conveying thickener in the flotation device for sewage treatment in the embodiment of the application. Figure 7 It is an enlarged schematic diagram of the local structure.

[0030] Label explanation:

[0031] 1. flotation tank; 101. coagulation reaction zone; 111. first agitator; 112. first water inlet; 113. first chemical inlet; 102. flocculation reaction zone; 121. second agitator; 122. second chemical inlet; 103. water distribution zone; 104. dissolved air water release zone; 141. water distribution plate; 142. water distribution hole; 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 outlet;

[0032] 2. coagulant chemical feeding system;

[0033] 3. flocculant chemical feeding system;

[0034] 4. scum conveyor; 401. inclined lifting section; 402. inclined platform;

[0035] 5. micro-bubble 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 collecting pipe; 541. first water collecting section; 542. second water collecting section; 543. non-water collecting section; 544. water collecting hole; 505. water storage tank; 551. water storage tank outlet; 506. air compressor; 507. bubble generating tank; 571. spiral mixing flow guide groove; 508. water inlet pump; 509. liquid level controller;

[0036] 6. sludge conveying and concentrating machine; 601. sludge concentrating motor; 602. sludge back pressure plate; 603. concentrating section housing; 604. screw shaft;

[0037] 7. intelligent control system. DETAILED DESCRIPTION

[0038] For a further understanding of the present application, reference will be made to the following detailed description taken in conjunction with the accompanying drawings and embodiments.

[0039] The structures, proportions, sizes, etc. shown in the drawings of the present specification are merely used to cooperate with the content disclosed in the present specification, to be understood and read by those skilled in the art, and are not used to limit the defined conditions under which the present application can be implemented, and therefore do not have substantial technical significance. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like used in the present specification are merely for the convenience of clear description, and are not used to limit the implementable range, and the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the implementable scope of the present application.

[0040] The flotation tank 1 is generally a rectangular box structure. The following embodiments are described with reference to the directions shown in the perspective view, Figure 1 from the perspective view, Figure 1 The direction of the line connecting the left and right sides in the middle is referred to as 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 flotation sludge conveyor 4 is referred to as the length direction of the flotation tank 1, Figure 2 The direction of the line connecting the upper and lower sides in the middle is referred to as the width direction of the flotation tank 1, that is, the horizontal direction perpendicular to the length direction described above is referred to as the width direction of the flotation tank 1.

[0041] The present embodiment provides a flotation device for sewage treatment, as shown in the perspective view, Figure 1 , Figure 2 , Figure 3 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 close to the water inlet thereof, a flotation sludge area 105 is formed at 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 on one side of the flotation sludge area 105 close to the water inlet of the flotation tank 1, and a flotation sludge conveyor 4, the flotation sludge conveyor 4 is located on one side of the flotation sludge area 105 away from the water inlet of the flotation tank 1, the flotation sludge conveyor 4 includes an inclined lifting section 401, one end of the inclined lifting section 401 extends into the flotation sludge area 105, and the other end is inclined upwardly towards the direction away from the second release branch 502, under the pushing action of the dissolved air water released at the outlet end of the second release branch 502, the flotation sludge in the flotation sludge area 105 moves towards the side where the flotation sludge conveyor 4 is located.

[0042] The present application adds a second release branch 502 to the micro-bubble dissolved air water generating system 5, the outlet end of the second release branch 502 is located on one side of the flotation sludge area 105 close to the water inlet of the flotation tank 1, the second release branch 502 releases dissolved air water towards the flotation sludge area 105 to push the flotation sludge in the flotation sludge area 105 to move towards the side where the flotation sludge conveyor 4 is located, the bottom end of the inclined lifting section 401 in the flotation sludge conveyor 4 extends into the flotation sludge conveyor 4, the inclined lifting section 401 is similar to the existing elevator, which drives the flotation sludge to move upwardly towards the direction away from the second release branch 502, that is, to lift towards the direction away from the outlet end of the second release branch 502, thereby separating the flotation sludge from the flotation sludge area 105.

[0043] The present application can achieve the following technical effects: a. The traditional slag scraper has a long movement route extending into the floating slag area. The present application only needs to extend the bottom end of the floating slag conveyor 4 into one side of the floating slag area 105. The contact area between the floating slag conveyor 4 and the floating slag area 105 is small, so the shaking of the floating slag conveyor 4 has little effect on the floating slag area, and it is not easy to cause the bubbles on the surface of the suspended matter to detach; b. The present application only needs to use the floating slag conveyor 4 to lift the floating slag for a certain distance so that it does not fall into the floating slag area 105. It does not need to move from one side of the floating slag area 105 to the other side. Therefore, the footprint size of the floating slag conveyor 4 along the length direction of the flotation tank 1 is greatly reduced compared with the traditional scraper-type slag scraper; c. The slag lifting method in the present application is continuous scraping. The traditional scraper-type slag scraping is non-continuous periodic scraping. Compared with the traditional slag scraping method, the floating slag is relatively continuous, and the thickness of the floating slag layer in the floating slag area 105 is relatively uniform; d. The bottom end of the floating slag conveyor 4 extends into the floating slag area 105 to separate the floating slag from the floating slag area 105 in a lifting manner. This separation method does not need to set a scraper and is not limited by the thickness of the floating slag layer and can adapt to different thicknesses of the floating slag layer; e. The dissolved air water released by the second release branch 502 pushes the floating slag in the floating slag area 105 to continuously move towards the floating slag conveyor 4. There is no dead angle for scraping, so the scraping is more thorough.

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

[0045] The micro-bubble dissolved air water generating system 5 is used to generate and transport micro-bubble dissolved air water. Specifically, as shown in Figure 1 、 Figure 2 , 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 draws water from the water storage tank 505 into the bubble generating tank 507. The gas inlet of the bubble generating tank 507 is connected to the output end of the air compressor 506. Specifically, there is a valve in the connecting pipeline between the water inlet pump 508 and the bubble generating tank 507. More specifically, the inside of the bubble generating tank 507 is also provided with a spiral mixing flow guide groove 571 and a liquid level controller 509. After the water and air are fully mixed in 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 proportion of air and water in the bubble generating tank 507. The bubble generating tank 507 outputs dissolved air water to the first release branch 501 and the second release branch 502.

[0046] Specifically, as shown in Figure 1 、 Figure 4As shown, the outlet end of the second release branch 502 is provided with a gas outlet pipe 521 in communication therewith, the gas outlet pipe 521 extends along the width direction of the flotation tank 1, and is provided with a long strip-shaped gas outlet belt or a plurality of gas outlet holes spacedly distributed and opening towards the side where the dross conveyor 4 is located. The slit along the height direction of the flotation tank 1 of the long strip-shaped gas outlet belt is preferably 4-6 mm, and the diameter of the circular gas outlet hole is preferably 8-12 mm.

[0047] The present application makes full use of the micro-bubble dissolved air water generating system 5 required by the existing flotation device, and additionally provides the 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 increase an additional micro-bubble dissolved air water generating system.

[0048] More specifically, the inclination angle of the inclined lifting section 401 with respect to the horizontal direction is 15-30°; and a dross collection area 109 is further provided below the end of the inclined lifting section 401 away from the dross area 105. The dross moves along the inclined lifting section 401 to the highest point, and then falls into the dross collection area 109.

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

[0050] As an extended solution, the inclined lifting section 401 is provided below with an inclined platform 402 spacedly arranged therefrom, and the inclination angles of the inclined lifting section 401 and the inclined platform 402 are the same. The inclined platform 402 is used for scraping the dross carried by the inclined lifting section 401 during the return process of the inclined lifting section 401, and guiding the sewage falling from the inclined lifting section 401.

[0051] The dross moves along the inclined lifting section 401 from the bottom end to the top end, the inclined lifting section 401 returns, and the dross falls from the inclined lifting section 401 to the dross collection area 109. At this time, if there is dross adhering to the inclined lifting section 401, the dross contacts the inclined platform 402, so as to achieve the effect of scraping the dross carried by the inclined lifting section 401, and the dross mixed with sewage moves upwards along the inclined lifting section 401, and the sewage falls from the inclined lifting section 401 to the inclined platform 402 under the action of gravity during the upward movement, and then flows back to the dross area 105.

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

[0053] As a further preferred embodiment of the above embodiments, the settling zone includes an inclined tube settling zone and a settling tank arranged from top to bottom in accordance with the law, and the bottom of the settling tank constitutes a sludge collection area 106; the inclined tube settling zone includes a first inclined tube settling zone 107 and a second inclined tube settling zone 108 located at the same horizontal height; the first inclined tube settling zone 107 and the second inclined tube settling zone 108 have opposite inclination directions, and the lower part of the adjacent ends forms a sewage drop blind zone.

[0054] Specifically, both the first inclined tube settlement zone 107 and the second inclined tube settlement zone 108 include multiple inclined tubes with the same inclination angle. The inclined directions of the inclined tubes in the first inclined tube settlement zone 107 and the second inclined tube settlement zone 108 are opposite. (Reference) Figure 1 As shown, wastewater settles from the inclined tube in the first inclined tube settling zone 107 in a direction from the upper right to the lower left, and wastewater settles from the inclined tube in the second inclined tube settling zone 108 in a direction from the upper left to the lower right. The tops of the first inclined tube settling zone 107 and the second inclined tube settling zone 108 are in contact, and there is no wastewater falling channel between the first inclined tube settling zone 107 and the second inclined tube settling zone 108. Wastewater can only settle into the sedimentation tank through the inclined tube in the first inclined tube settling zone 107 and the second inclined tube settling zone 108. The bottoms of the first inclined tube settling zone 107 and the second inclined tube settling zone 108 are far apart, thus forming a fan-shaped wastewater falling blind zone.

[0055] As a preferred embodiment of the microbubble dissolved air water generation system 5, the microbubble dissolved air water generation system 5 includes a water storage tank 505 and a water collection pipe 504. One end of the water collection 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 collection pipe 504 includes a first water collection section 541, a second water collection section 542, and a non-water collection section 543 that are coaxial and connected in sequence. The second water collection section 542 is located directly below the blind zone of sewage flow. The density of water collection holes 544 in the second water collection section 542 is greater than that in the first water collection section 541 and the non-water collection section 543.

[0056] As shown above, the interior of the water storage tank 505 is connected to the upper part of the sedimentation tank via a water collection pipe 504. Water from the sedimentation tank enters the water storage tank 505 through the water collection pipe 504. Water is drawn from the sedimentation tank through the water collection pipe 504, thereby saving water resources.

[0057] As can be seen from the trajectory of the sewage falling through the first inclined tube settling zone 107 and the second inclined tube settling zone 108, the sewage falls far away from the second collection section 542. Therefore, the disturbance to the settled sewage in the area where the second collection section 542 is located is relatively small. The sewage in the area where the second collection section 542 is located is mainly settled sewage with a relatively low sludge content. Therefore, more water collection holes are opened in the second collection section 542. That is, the density of water collection holes 544 in the second collection section 542 is greater than that in the first collection section 541 and the non-collection section 543. This can increase the speed and volume of water entering through the second collection section 542, thereby improving the clarity of the sewage in the storage tank 505 and reducing the adverse effects of the dynamic settling of sewage in the settling tank on the water entering the storage tank 505.

[0058] As an extension, a water tank outlet 551 is provided on one side of the water tank 505. 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 extended implementation method, refer to Figure 1 , Figure 5 As shown, the first inclined tube settling zone 107 is located close to the dissolved air water release zone 104, and the second inclined tube settling zone 108 is located below the inclined lifting section 401. The size of the first inclined tube settling zone 107 along the length of the flotation tank 1 is larger than the size of the second inclined tube settling zone 108. The non-collecting 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 in the first collecting section 541 is greater than that in the non-collecting section 543.

[0060] As described above, the first water collection section 541 is located below the first inclined tube settling zone 107. Preferably, there is a gap between the inner wall of the settling tank and the end of the first water collection section 541 along its axial direction.

[0061] In a further preferred embodiment, the non-collection section 543 does not have a collection hole 544. During the lifting process by the scum conveyor 4, the sewage mixed with scum falls into the scum layer above the second inclined tube settling zone 108. The sewage mixed with scum flows down through the second inclined tube settling zone 108. Therefore, the sewage obtained after settling in the second inclined tube settling zone 108 has relatively large impurities. Therefore, the non-collection section 543 below the second inclined tube settling zone 108 does not have a collection hole 544.

[0062] refer to Figure 6 As shown, the water collection holes 544 are symmetrically distributed on both sides of the vertical axis of symmetry of the water collection pipe 504, and open downwards at an angle relative to the horizontal axis of symmetry of the water collection pipe 504, with the angle between the center line and the vertical direction between 30° and 45°.

[0063] Further preferably, the water storage tank 505 is arranged close to the second inclined pipe sedimentation zone 108, and the pool bottom of the sludge collection zone 106 is arranged to be inclined downward along the direction close to the water storage tank 505.

[0064] As a further preferred embodiment of any of the above-mentioned embodiments, the outlet end of the first release branch 501 is provided with a plurality of first dissolved air water release devices 511 in communication therewith, the plurality of first dissolved air water release devices 511 are spaced apart along the width direction of the flotation tank 1 and located directly above the water distribution plate 141 in the dissolved air water release zone 104; the density of the water distribution holes 142 in the water distribution plate 141 in the area directly below the adjacent two first dissolved air water release devices 511 is greater than that in the remaining area.

[0065] It should be noted that the first dissolved air water release device 511 generally includes a plurality of dissolved air water release ports spaced apart in the circumferential direction. Referring to Figure 1 , a single first dissolved air water release device 511 is provided with eight dissolved air water release ports uniformly distributed in the circumferential direction, and the distribution density of the dissolved air water release ports in the interval area between the adjacent two first dissolved air water release devices 511 is greater than that in other areas of the dissolved air water release zone 104. Accordingly, the dissolved air water release density in the area between the adjacent two first dissolved air water release devices 511 is greater, and therefore more water distribution holes 142 are provided in the area directly opposite the water distribution plate 141. According to the release density of the dissolved air water in the first dissolved air water release device 511, the opening density of the water distribution holes 142 in the water distribution plate 141 in different areas is set to improve the uniformity of the mixing of dissolved air water and sewage.

[0066] In order to improve the effluent quality of the sedimentation tank, referring to Figure 7 , Figure 8 , the bottom of the sludge collection zone 106 is provided with a sludge conveying thickener 6, which includes a screw shaft 604 and a spiral blade arranged around the outside of the screw shaft 604. The inlet end of the thickening section housing 603 is in communication with the outlet end of the sludge collection zone 106. One end of the screw shaft 604 is located inside the sludge collection zone 106, and the other end extends into the inside of the thickening section housing 603, and the outside of this end is sleeved with a sludge back pressure plate 602. The distance between the sludge back pressure plate 602 and the outlet end of the thickening section housing 603 is adjustable. The output end of the sludge thickening motor 601 is connected to the end of the screw shaft 604 through a reducer and a coupling, and the sludge thickening motor 601 drives the screw shaft 604 to rotate. By arranging the sludge conveying thickener 6, the sludge in the sludge collection zone 106 is concentrated and discharged.

[0067] The sludge back pressure plate 602 and the discharge end of the thickening section shell 603 form a sludge gap outlet, and the thickness of the sludge cake after compression is controlled by adjusting the distance between the sludge back pressure plate 602 and the discharge end of the thickening section shell 603, and then the moisture content of the sludge cake is controlled.

[0068] Preferably, in the direction from one end of the screw shaft 604 inside the sludge collection area 106 to the other end, the shaft diameter of the screw shaft 604 gradually increases and is arranged with an upward inclination of 2-5°, and the pitch of the helical blade gradually decreases, so that the volume of the helical sealing cavity formed between adjacent helical blades gradually decreases, and the water carried in the sludge is continuously squeezed out, and at the same time the falling of the water carried in the sludge is facilitated.

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

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

[0071] The coagulation reaction area 101 is provided with a first water inlet 112 for the entry of sewage and a first dosing port 113 for the addition of coagulant. In order to improve the mixing effect of the reagent, the inside of the coagulation reaction area 101 is provided with a first agitator 111.

[0072] The water inlet of the flocculation reaction area 102 is connected with the water outlet of the coagulation reaction area 101, and the flocculation reaction area 102 is provided with a second dosing port 122 for the addition of flocculant. In order to improve the mixing effect of the reagent, the inside of the flocculation reaction area 102 is provided with a second agitator 121.

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

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

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

[0076] S2, the sewage in the dissolved air water releasing area 104 meets the dissolved air water released from the outlet end of the first releasing branch 501, and the dissolved air water drives the scum in the sewage to go up to the scum area 105;

[0077] S3, the dissolved air water released from the outlet end of the second releasing branch 502 drives the scum in the scum area 105 to move towards the side where the scum conveyor 4 is located;

[0078] S4, the scum conveyor 4 lifts the scum in the scum area 105 and drives it to go up in the direction away from the scum area 105, so as to separate the scum from the scum area 105; the scum enters the scum collecting area 109 and then is discharged to the outside of the flotation tank 1;

[0079] S5, the sewage enters the inclined pipe settling area through the scum area 105, goes down through the inclined pipe settling area to the settling tank, and then settles in the settling tank to the sludge collecting area 106; the sludge conveying thickener 6 conveys the sludge in the sludge collecting area 106 to the outside of the flotation tank 1 and compresses it into a sludge cake;

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

[0081] The above description of the present application and its embodiments is illustrative and not restrictive, and the embodiments shown in the drawings are only one of the embodiments of the present application, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it, without departing from the purpose of the present application, similar structural forms and embodiments can be designed without creativity, which should belong to the protection scope of the present application.

Claims

1. A flotation device for sewage treatment, characterized by comprising: The application relates to a flotation tank (1) which is internally provided with a dissolved air water releasing area (104) near one side of a water inlet of the flotation tank (1), and a scum area (105) is formed at the top of the flotation tank (1) during the flotation process. A micro-bubble dissolved air water generating system (5) is arranged on the flotation tank (1), the micro-bubble dissolved air water generating system (5) comprises a first releasing branch (501) and a second releasing branch (502), the outlet end of the first releasing branch (501) extends into the dissolved air water releasing area (104), the outlet end of the second releasing branch (502) is located on one side of the scum area (105) near the water inlet of the flotation tank (1), and the outlet end of the second releasing branch (502) is provided with an air outlet pipe (521) which is in communication with the second releasing branch (502), the air outlet pipe (521) extends along the width direction of the flotation tank (1), and is provided with a long strip-shaped air outlet belt or a plurality of air outlet holes which are spacedly arranged and open towards one side where a scum conveyor (4) is located. The scum conveyor (4) is arranged on one side of the scum area (105) away from the water inlet of the flotation tank (1), and the scum conveyor (4) comprises an inclined lifting section (401), one end of the inclined lifting section (401) extends into the scum area (105), and the other end is arranged to be inclined upwards in a direction away from the second releasing branch (502), under the pushing action of the dissolved air water released from the outlet end of the second releasing branch (502), the scum in the scum area (105) moves towards one side where the scum conveyor (4) is located. The inclined angle between the inclined lifting section (401) and the horizontal direction is 15-30 degrees, and a scum collecting area (109) is further arranged below one end of the inclined lifting section (401) away from the scum area (105).

2. The flotation device for sewage treatment according to claim 1, characterized by The dissolved air water releasing area (104) is located on the bottom of the flotation tank (1), the bottom of the flotation tank (1) is further provided with a settling area which is located on one side of the dissolved air water releasing area (104) near the scum conveyor (4), the flotation tank (1) and the settling area are separated by a partition plate, and are in communication with each other through the scum area (105).

3. The flotation device for sewage treatment according to claim 2, characterized by The settling area comprises an inclined pipe settling area and a settling tank arranged from top to bottom, the bottom of the settling tank constitutes a sludge collecting area (106), the inclined pipe settling area comprises a first inclined pipe settling area (107) and a second inclined pipe settling area (108) located at the same horizontal height, the inclined directions of the first inclined pipe settling area (107) and the second inclined pipe settling area (108) are opposite, and the lower parts of adjacent ends form a blind area for sewage falling.

4. The flotation device for sewage treatment according to claim 3, characterized by 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 in the water storage tank (505), the other end extends into the upper part of the settling 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 in communication, the second water collecting section (542) is located directly below the blind area for sewage falling, and the density of water collecting holes (544) arranged in the second water collecting section (542) is greater than that of the first water collecting section (541) and the non-water collecting section (543).

5. The flotation device for sewage treatment according to claim 4, characterized by ​ 6. The flotation device for sewage treatment according to claim 5, characterized by The first inclined pipe settling zone (107) is arranged close to the dissolved air water release zone (104), the second inclined pipe settling zone (108) is arranged close to the dregs conveyor (4) and below the inclined lifting section (401), the size of the first inclined pipe settling zone (107) along the length direction of the flotation tank (1) is greater than the size of the second inclined pipe settling zone (108); the non-water collecting section (543) is directly below the lower end of the second inclined pipe settling zone (108); the first water collecting section (541) has a greater density of water collecting holes (544) than the non-water collecting section (543).

7. The flotation device for sewage treatment according to claim 6, characterized by The water storage tank (505) is arranged close to the second inclined pipe settling zone (108), and the bottom of the sludge collecting zone (106) is arranged to be inclined downward along the direction close to the water storage tank (505).

8. A flotation device for sewage treatment according to any one of claims 1-7, characterized in that The outlet end of the first release branch (501) is provided with a plurality of first dissolved air water release devices (511) in communication therewith, the plurality of first dissolved air water release devices (511) are distributed 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 zone (104); the density of water distribution holes (142) in the area of the water distribution plate (141) directly below the adjacent two first dissolved air water release devices (511) is greater than the density of the remaining areas.

9. A flotation device for sewage treatment according to any one of claims 1-7, 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) connected in sequence, the water inlet of the dissolved air water release zone (104) is connected with the water outlet of the water distribution zone (103); the coagulant dosing system (2) is used to provide coagulant for the coagulation reaction zone (101), and the flocculant dosing system is used to provide flocculant for the flocculation reaction zone (102); And / or the inclined lifting section (401) is provided with an inclined platform (402) arranged at intervals therefrom, and the inclined angles of the inclined lifting section (401) and the inclined platform (402) are the same.

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