JP4825850B2 - Floating separator, rectifier, and split cell for rectifier - Google Patents

Description

  The present invention relates to a technique of a levitation separation device that attaches bubbles to a substance to be treated in water to be treated and separates the substance to be treated as a floating substance.

  Conventionally, as a method of removing SS components, oils, and other substances to be treated contained in the water to be treated, the water to be treated and bubbles are mixed and supplied to the levitation tank. A levitation process is known that floats on the surface of a tank and separates a substance to be treated. In addition, in order to raise processing efficiency, before supplying to-be-processed water to a levitation tank, a flocculant is added and the to-be-processed substance contained in to-be-processed water is made to flock.

  For example, Patent Document 1 discloses a levitation separation device that attaches bubbles to a substance to be treated in the water to be treated and separates the substance to be treated as a floating substance. FIG. 8 is a schematic diagram showing the configuration of the flotation separation device of Patent Document 1. As shown in FIG. In the levitation separation apparatus 3 shown in FIG. 8, the peripheral wall 60a of the levitation tank 60 is rectangular, and the treated water is detoured in the vertical direction by the upper open partition 62a and the lower open partition 62b. The three chambers are divided into a first chamber 64, a second chamber 66, and a third chamber 68. Further, the rectifying unit 70 is horizontally installed between the partition wall 62a and the partition wall 62b of the second chamber 66, and the second chamber 66 is partitioned into an upper portion 67a and a lower portion 67b in the vertical direction. A plurality of rectifying holes 70 a are formed in the rectifying unit 70, and water from the second chamber 66 to the third chamber 68 passes through the rectifying unit 70. A treated water inflow pipe 72 is connected to the first chamber 64. One end of the pressurized water inflow pipe 74 is connected to the first chamber 64, and the other end is connected to the outlet of the air dissolution tank 75. A treated water discharge pipe 76 is connected to the third chamber 68. A communication pipe 80 is connected between the air dissolution tank 75 and the treated water discharge pipe 76 via a pump 78, and a part of the treated water passing through the treated water discharge pipe 76 passes through the communication pipe 80, and the air dissolution tank 75. In the air dissolution tank 75, air is dissolved in the treated water to produce pressurized water.

  In such a levitation separator 3, the water to be treated that has flowed into the first chamber 64 from the water to be treated 72 and the pressurized water that has flowed from the air dissolution tank 75 through the pressurized water inflow tube 74 into the first chamber 64 are liquid. It rises toward the surface and flows into the upper portion 67a of the adjacent second chamber 66. In the upper portion 67a of the second chamber 66, the gas dissolved in the pressurized water is deposited as bubbles, adheres to the material to be treated (SS component, oil, etc.) in the water to be treated, and the material to be treated is floated and separated. The treated water from which the material to be treated has been removed passes through the rectifying hole 70 a provided in the rectifying unit 70, is supplied to the lower portion 67 b of the second chamber 66, and is discharged from the third chamber 68 to the treated water discharge pipe 76. .

US Patent Application Publication No. 2005/0115881

  By the way, a material to be processed having a high specific gravity that cannot float even if bubbles are attached, or a material to be processed to which bubbles are not sufficiently attached are deposited at the bottom of the levitation tank 60. FIG. 9 is a schematic cross-sectional view showing a configuration of a rectifying unit used in the floating separation device of Patent Document 1. As shown in FIG. 9, the rectifying hole 70 a (in FIG. 9, the rectifying hole 70 a is represented by a hatched portion) extends from the upper opening 71 a opened to the upper portion 67 a side of the floating tank 60 to the lower 67 b side of the floating tank 60. The horizontal cross-sectional area of the rectifying hole 70a is the same up to the opened lower opening 71b. In such a configuration, the deposit is not easily discharged to the lower portion 67 b side of the floating tank 60 and is deposited on the rectifying unit 70. When the deposit accumulates on the rectifying unit 70, a large amount of the precipitate is easily discharged to the third chamber 68 side at once by the treated water passing through the rectifying hole 70a. As a result, the quality of the treated water due to continuous operation of the apparatus deteriorates, making it impossible to effectively use the treated water or discharge it as environmental water.

  Then, the objective of this invention is providing the floating separation processing apparatus which can suppress the water quality deterioration of the treated water by the continuous driving | operation of an apparatus.

  The present invention is a levitation separator that attaches bubbles to a substance to be treated in water to be treated and separates the substance to be treated as a levitated substance, and includes a levitation tank and a rectifier that divides the levitation tank into an upper part and a lower part in a vertical direction. And an inflow part for allowing treated water to flow into the upper part, and a water collecting part for collecting treated water from which the treated substance is separated from the lower part, and the rectifying part The rectifying hole includes a plurality of rectifying holes that allow water to pass therethrough, and the rectifying hole includes an upper opening, a lower opening that is smaller than an area of the upper opening, and a slope that extends from the upper opening to the lower opening. .

  Further, in the levitation separation apparatus, the rectifying holes are arranged so that upper openings are adjacent to each other.

  In the levitation separation apparatus, the slope angle of the slope portion is preferably in the range of 45 ° to 75 °, and more preferably 60 °, which is a repose angle of a general aggregated floc.

  In the levitation separation apparatus, it is preferable that the rectifying unit includes a plurality of divided cells, and the divided cells include at least one rectifying hole.

  In the floating separation apparatus, the area of the lower opening relative to the area of the upper opening is preferably in the range of 2 to 10%.

  In the levitation separation apparatus, the levitation tank may have a rectangular shape or a polygonal shape other than a pentagon, but is preferably cylindrical.

  Further, the present invention is a rectifier that divides a levitation tank of a levitation separator that separates a substance to be treated as a levitated substance into upper and lower parts in the vertical direction by attaching bubbles to the substance to be treated in the treatment water. The rectifying device includes a plurality of rectifying holes through which treated water flows, and the rectifying holes include an upper opening, a lower opening smaller than an area of the upper opening, and the upper opening to the lower opening. And a slope portion to reach.

  Moreover, in the rectifier, the rectifier is preferably composed of a plurality of divided cells, and the divided cells preferably include at least one rectifying hole.

  The present invention also relates to a rectifier that constitutes a rectifier that divides a levitation tank of a levitation separator that vertically separates a substance to be treated as a levitated substance by separating bubbles into the substance to be treated in the treatment water. The dividing cell for rectifier includes at least one rectifying hole for allowing treated water to flow, and the rectifying hole has an upper opening and a lower opening smaller than an area of the upper opening. And a slope portion extending from the upper opening to the lower opening.

  According to the flotation separation apparatus of the present invention, it is possible to suppress sediment accumulation on the rectification unit and to suppress deterioration of the quality of treated water due to continuous operation of the apparatus.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment.

  FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the levitation separation apparatus according to the present embodiment. A levitation separation apparatus 1 shown in FIG. 1 includes a levitation tank 10, an inflow section 12, a discharge section 14, and a rectification section 22 (rectification apparatus).

  The peripheral wall 10a of the levitation tank 10 shown in FIG. 1 has a cylindrical shape, and the bottom 10b of the levitation tank 10 has a hopper shape that becomes lower toward the center. A pit 18 is provided at the center of the bottom portion 10b to collect a deposit of the material to be treated. The pit 18 is provided with a sediment discharge port (not shown), and a sediment discharge pipe 19 is connected thereto. The peripheral wall 10a of the floating tank 10 may be rectangular. However, by forming the peripheral wall 10a of the levitation tank 10 into a cylindrical shape, the water to be treated spreads from the opening portion (the opening portion will be described later) of the inflow portion 12 disposed at the center of the levitation tank 10 to the peripheral wall 10a. It will flow while. Therefore, although the flow velocity when exiting the inflow portion 12 is relatively fast, the flow of the surface portion when hitting the peripheral wall 10a is relatively slow. As a result, since a rapid downward flow does not occur in a part of the peripheral wall 10a, the entire levitation tank can be effectively used for the levitation separation process, and the processing capacity can be improved.

  The floating tank 10 is provided with a water collecting part 10c. The water collection unit 10c collects treated water from which the substance to be treated has been removed from the lower part 20b of the floating tank 10 described later, and is disposed on the lower part 20b side of the floating tank 10, that is, below the rectifying unit 22 in the vertical direction. The

  The levitation tank 10 is provided with a levitation object pot 24 for discharging the levitation material 23 (so-called scum) that has floated on the liquid surface among the substances to be treated. In a normal case, a skimmer for scraping the levitated object 23 is provided on the surface of the levitating tank 10, and the levitated object 23 is scraped to the levitated object pot 24. Further, the levitated pot 24 has a slope extending from the lower surface to the upper surface of the water at the boundary portion of the levitating tank 10 side so that the levitated object 23 that is scraped down falls into the levitated pot 24 from the water surface. Is preferred.

  In the levitation tank 10, a rectification unit 22 is provided that partitions the levitation tank 10 into an upper part 20a and a lower part 20b in the vertical direction. And in the rectification | straightening part 22, the some rectification | straightening hole 22a which lets treated water flow is formed. FIG. 2 is a schematic top view illustrating an example of the configuration of the rectifying unit used in the present embodiment. FIG. 3 is a schematic cross-sectional view illustrating an example of the configuration of the rectifying unit along line AA in FIG. 2. In the present embodiment, the rectifying hole 22a (in FIG. 3, the rectifying hole 22a is indicated by a hatched portion) is provided on the upper opening 25a opened on the upper part 20a side of the floating tank 10 and on the lower part 20b side of the floating tank 10. It has an opened lower opening 25b and a slope portion 25c extending from the upper opening 25a to the lower opening 25b.

  Usually, a heavy material to be treated that cannot float even if bubbles are attached to the upper part 20a of the levitation tank 10, or a part of the material to be treated that is not sufficiently attached with bubbles is deposited on the rectifying unit 22. . However, in the present embodiment, the structure is such that sediment is easily discharged to the lower opening 25b side by the upper opening 25a and the slope 25c having a larger area than the lower opening 25b. Therefore, the deposit is hardly deposited on the rectifying unit 22 and in the rectifying hole 22a. Further, as shown in FIG. 3, the rectifying holes 22a are preferably arranged so that the upper openings 25a are adjacent to each other. With the above configuration, since there is no gap between the upper openings 25a, it is possible to effectively suppress deposits from being deposited on the rectifying unit 22. The shape of the upper opening 25a is not particularly limited, but is preferably a polygonal shape such as a square in that the upper opening 25a can be adjacent to each other without a gap.

  As shown in FIG. 3, the slope portion 25c is configured to gradually incline from the upper opening portion 25a to the lower opening portion 25b, that is, the horizontal section in the rectifying hole 22a from the upper opening portion 25a toward the lower opening portion 25b. The area is gradually reduced. However, the shape of the slope portion 25c is not limited to the above as long as it is a shape that easily discharges sediment to the lower opening portion 25b side. FIG. 4 is a schematic cross-sectional view showing another example of the configuration of the rectifying unit along line AA in FIG. For example, as shown in FIG. 4, the slope portion 25c is configured to gradually incline from the upper opening 25a to a predetermined position below, and is configured to be a vertical surface from the predetermined position to the lower opening 25b. The horizontal cross-sectional area in the rectifying hole 22a is gradually reduced from the upper opening 25a to a predetermined position below, and the horizontal cross-sectional area in the rectifying hole 22a is reduced from the predetermined position to the lower opening 25b. May be configured to be the same.

  The slope angle (θ) of the slope portion 25c is preferably in the range of 45 ° to 75 °, more preferably in the range of 60 °. If the inclination angle of the slope portion 25c is smaller than 45 °, precipitates may be deposited on the slope portion 25c. Moreover, when the inclination angle of the slope portion 25c is larger than 75 °, the strength of the rectifying portion 22 may not be sufficiently secured.

  The rectifying unit 22 may be an integrated structure in which the rectifying hole 22a described above is formed on a plate made of a resin material or the like, but the rectifying unit 22 of the present embodiment is used for a floating tank of a different size. In terms of easy installation, the rectifying unit 22 is preferably configured by a plurality of divided cells (divided cells for a rectifier) made of a resin material or the like. 5A to 5C are schematic perspective views showing the configuration of the divided cells. As shown in FIGS. 5A to 5C, at least one rectifying hole 22 a described above is formed in the divided cell 27. The rectification unit 22 is formed by combining the divided cells 27 so as to fit the size of the floating tank 10. The rectifying unit 22 including the rectifying unit 22 or the divided cell 27 having an integral structure is fixed to the peripheral wall 10a of the levitation tank 10 by a frame, a gantry, or the like (not shown).

  In the present embodiment, the area of the lower opening 25b relative to the area of the upper opening 25a (hereinafter sometimes referred to as an opening area ratio) is preferably in the range of 2 to 10%. When the opening area ratio is lower than 2%, the flow rate of the treated water flowing through the rectifying hole 22a is increased, and the precipitate is likely to flow into the water collecting portion 10c together with the treated water, which may deteriorate the quality of the treated water. Moreover, since the loss head of the treated water flowing through the apparatus rises, it is necessary to raise the water level of the levitation tank 10 correspondingly, and the apparatus becomes large. Further, if the opening area ratio is larger than 10%, the rectifying effect of the rectifying unit 22 may not be sufficiently exhibited.

  The inflow portion 12 includes a guide tube 26 and an introduction pipe 28 provided in the guide tube 26. A treated water inflow pipe 30 is connected to the introduction pipe 28, and the introduction pipe 28 extends from the pit 18 formed in the center of the bottom 10 b of the levitation tank 10 into the levitation tank 10. A pressurized water inflow pipe 32 is connected to the treated water inflow pipe 30. The guide tube 26 provided in the floating tank 10 is fixed to the bottom 10b and the peripheral wall 10a with a frame or the like. The guide tube 26 may be suspended from above. By providing the guide tube 26, the water to be treated and the pressurized water supplied from the introduction pipe 28 can be uniformly introduced from the central portion of the levitation tank 10.

  The inflow part 12 of this embodiment is opened at the upper part 20a of the levitation tank 10, and the treated water (mixed with pressurized water) is supplied from the opening part to the upper part 20a of the levitation tank 10. Here, when the inflow part 12 is comprised from the guide cylinder 26 and the introductory tube 28 like this embodiment, the opening part 26a of the guide cylinder 26 should just open at the upper part 20a. The inflow portion 12 of this embodiment does not necessarily need to include the guide tube 26. For example, the inflow portion 12 may be composed only of the introduction pipe 28. In this case, the opening portion 28a of the introduction pipe 28 needs to be opened at the upper portion 20a. In particular, the water to be treated is preferably allowed to flow into the center of the upper part 20a of the levitation tank 10, for example, 1/3 from the center with respect to the distance from the center to the peripheral wall 10a in the horizontal section of the upper part 20a of the levitation tank 10. It is preferable to flow into the area within.

  The position of the opening portion of the inflow portion 12 (in FIG. 1, the opening portion 26a of the guide tube 26) is not particularly limited as long as it is vertically above the upper portion 20a of the floating tank 10, that is, the rectifying portion 22. However, if the position of the opening of the inflow portion 12 is near the liquid level, the water to be treated supplied from the opening of the inflow portion 12 spouts up to the liquid surface, disturbs the liquid surface, and floats to the liquid surface. There is a risk of re-sedimentation of the object 23.

  The discharge unit 14 includes a treated water extraction pipe 38, a water level adjustment tank 40, and a treated water discharge pipe 42. One end of the treated water outlet pipe 38 is connected to a water collecting part 10 c provided in the floating tank 10, and the other end of the treated water outlet pipe 38 is connected to the inlet of the water level adjusting tank 40. A treated water discharge pipe 42 is connected to the outlet of the water level adjustment tank 40.

  Next, an example of the operation method by the levitation separator according to the present embodiment will be described. First, the water to be treated is caused to flow from the water to be treated inflow pipe 30 and the pressurized water in which the gas is dissolved from the pressure water inflow pipe 32 under high pressure. Pressurized water is generated by introducing a part of treated water into an air dissolution tank and dissolving the air under high pressure.

  The pressurized water that passes through the pressurized water inflow pipe 32 is mixed with the treated water that passes through the treated water inflow pipe 30. A mixed liquid composed of water to be treated and pressurized water is supplied from the water to be treated inflow pipe 30 to the introduction pipe 28. The water to be treated and the pressurized water are supplied into the guide tube 26 from the opening 28 a of the introduction pipe 28 through the introduction pipe 28. Water to be treated and pressurized water supplied into the guide cylinder 26 (rising toward the liquid level of the levitation tank 10) flow into the upper part 20 a of the levitation tank 10 from the opening 26 a of the guide cylinder 26. Since the upper part 20a of the levitation tank 10 (and the inside of the guide cylinder 26) is in an atmospheric pressure state, the gas dissolved in the pressurized water is precipitated as bubbles, and becomes a substance to be treated (SS component, oil, etc.) in the treated water. It adheres and the material to be treated floats and is separated. The material to be treated (the levitated material 23) that has floated in this manner is collected in the levitated material pot 24. The collection of the floating object 23 is normally performed by a floating object skimmer described later, but may be performed by other methods. The float 23 collected in the float pot 24 is discharged from the float discharge pipe 44 connected to the discharge port of the float pot 24. The method of generating bubbles is not limited to the method using pressurized water as described above, but may be a method of adding a bubble generating agent such as a surfactant to the water to be treated. . Alternatively, a whole-pressure method may be employed in which the water to be treated itself is introduced into an air dissolution tank and air is directly dissolved in the water to be treated.

  When the water to be treated supplied from the opening 26a of the guide tube 26 to the upper portion 20a of the levitation tank 10 reaches the peripheral wall 10a of the levitation tank 10, a downward flow flows along the peripheral wall 10a. Therefore, in the present embodiment, it is preferable that the opening 26a of the guide cylinder 26 opens vertically upward at the center of the upper portion 20a of the levitation tank 10, and the peripheral wall 10a of the levitation tank 10 is cylindrical. With the above configuration, the water to be treated becomes a dispersed flow that spreads radially and reaches the peripheral wall 10a of the levitation tank 10 as shown in FIG. As a result, the flow of the water to be treated supplied from the opening 26a becomes gentle before reaching the peripheral wall 10a of the levitation tank 10, and the downward flow of the water to be treated flowing along the peripheral wall 10a also becomes gentle. Therefore, deterioration of the quality of the treated water caused by the rapid downward flow is suppressed.

  Here, the shape of the opening of the inflow portion 12 (in FIG. 1, the opening 26a of the guide tube 26) is not particularly limited, but the water to be treated supplied from the opening of the inflow portion 12 is dispersed radially. From the viewpoint of facilitating this, it is preferable that the upper portion of the upper portion spreads in a tapered shape. In addition, the horizontal cross-sectional area of the opening of the inflow portion 12 is not particularly limited, but it is preferable that the flow rate of the water to be treated flowing through the inflow portion 12 can be appropriately controlled. It is good to set it as the range of 1/20 to 1/8 of the horizontal cross-sectional area of the horizontal cross-sectional area of the horizontal cross-sectional area of the horizontal tank of the floating tank 10, More preferably. If the horizontal cross-sectional area of the opening of the inflow portion 12 is smaller than 1/30 of the horizontal cross-sectional area of the levitation tank 10, the flow rate of the water to be treated when exiting the inflow portion 12 is increased. The flow rate of the water to be treated flowing from the opening toward the peripheral wall 10a of the levitation tank 10 is increased, the liquid surface of the levitation tank 10 is likely to be disturbed, and the floating object 23 that has floated to the liquid surface is regenerated. There is a risk of causing sedimentation. Moreover, since the downflow of the to-be-processed water which flows along the surrounding wall 10a of the levitation tank 10 also becomes quick, the whole rectification | straightening part 22 cannot be utilized effectively, the rectification effect reduces, and the quality of the treated water is reduced. It can get worse. Moreover, when the horizontal cross-sectional area of the opening part of the inflow part 12 is larger than 1/3 of the horizontal cross-sectional area of the levitation tank 10, it becomes difficult to ensure the area of the levitation tank 10, and the water area load of the levitation tank 10 is large. Therefore, efficient levitation processing cannot be performed.

  In the upper part 20 a of the levitation tank 10, the treated water from which the substance to be treated has been removed passes through the rectification holes 22 a provided in the rectification unit 22 and is supplied to the lower part 20 b of the levitation tank 10. The flow of the treated water flowing from the upper part 20a to the lower part 20b is rectified by the lower opening 25b of the rectifying part 22. That is, the flow rate of the treated water flowing from the upper part 20a to the lower part 20b is made almost uniform everywhere due to the rectifying effect of the rectifying unit 22. As a result, the entire upper part 20a of the levitation tank 10 can be used for the levitation separation process, and bubbles can be efficiently attached to the material to be treated, so that the processing capacity can be improved.

  In addition, as described above, normally, a material to be processed having a high specific gravity that cannot float even if bubbles are attached, or a part of a material to be processed to which bubbles are not sufficiently attached are placed on the rectifying unit 22. accumulate. However, the rectifying unit 22 according to the present embodiment extends from the upper opening 25a (the upper openings 25a are preferably adjacent to each other) having a larger area than the lower opening 25b and the upper opening 25a to the lower opening 25b. Since the slope portion 25c is formed, the deposit is hardly deposited on the rectifying portion 22 and in the rectifying hole 22a. As a result, the deterioration of the quality of the treated water due to the continuous operation of the apparatus can be suppressed, so that the treated water can be effectively used and discharged as environmental water.

  The treated water supplied to the lower part 20b of the levitation tank 10 through the rectifying hole 22a formed in the rectifying part 22 passes through the treated water outlet pipe 38 from the water collecting part 10c of the levitation tank 10 to the water level adjusting tank 40. Supplied. A movable weir 41 is provided in the water level adjustment tank 40. By adjusting the height of the movable weir 41, the water level in the levitation tank 10 can be adjusted, and the water level in the levitation tank 10 is adjusted to a water level suitable for discharging the float 23 to the float pot 24. Then, the treated water is discharged from the outlet of the water level adjustment tank 40 to the treated water discharge pipe 42. In addition, it is also possible to raise the movable weir 41 intermittently and thereby overflow the floating material 23 in the floating tank 10 to the floating material pot 24.

  FIG. 6 is a schematic cross-sectional view showing an example of the configuration of a levitation separator according to another embodiment of the present invention. A levitation separation apparatus 2 shown in FIG. 6 is obtained by providing a levitation skimmer 50 and a sediment scraper 52 in the levitation separation apparatus 1 shown in FIG. In the levitation separator 2 shown in FIG. 6, the same components as those in the levitation separator 1 shown in FIG.

  The levitated skimmer 50 is for scraping the levitated matter 23 that has levitated to the liquid surface. The levitated skimmer 50 is fixed to the shaft of the motor 54. When the motor 54 is driven, the levitated skimmer 50 is rotated, and the levitated object 23 that has levitated to the liquid surface is scraped. The levitated skimmer 50 has scraper portions such as blades and spiral vanes, and the levitated matter 23 is moved radially outward by the flow of the water surface and the movement of the scraper portion, and the levitated matter provided in the levitating tank 10. They are collected in the pot 24 and discharged from the floating material discharge pipe 44. By providing the levitated skimmer 50, the levitated matter 23 can be discharged efficiently, so that deterioration of the quality of the treated water can be suppressed.

  The sediment scraper 52 is for scraping the sediment deposited on the bottom 10 b of the floating tank 10. The sediment scraper 52 is attached to the guide tube 26, and the angle of the sediment scraper 52 is reinforced by a support 56. The guide cylinder 26 is attached to the shaft of the motor 54 and is rotated by driving the motor 54. That is, the sediment scraper 52 is rotated integrally with the guide cylinder 26 by the drive of the motor 54. As the sediment scraper 52 rotates, the sediment deposited on the bottom 10 b of the floating tank 10 is scraped, collected in the pit 18 of the floating tank 10, and discharged from the sediment discharge pipe 19. In addition, this sediment scraper 52 also has scraper parts, such as a blade | wing and a spiral blade, and scrapes a sediment inside by this scraper part.

  Here, in the past, regular maintenance was required to clean the sediment. However, by providing the sediment scraper 52, the sediment can be efficiently discharged, so the number of maintenance times is reduced. The system can be operated continuously for a long time.

  Note that a rectifying unit scraper that scrapes the sediment precipitated on the rectifying unit 22 and drops and discharges it downward from the rectifying hole 22a of the rectifying unit 22 may be provided. However, as described above, the rectifying unit of this embodiment is also provided. Since almost no sediment is deposited on the part 22, it is not always necessary to provide a rectifying part scraper.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

Using the floating separation device 2 of FIG. 6, the floating separation treatment was performed under the following conditions, and the turbidity of the treated water after the floating separation was measured. As shown in FIG. 3, the rectifying unit 22 used in the embodiment includes an upper opening 25a, a lower opening 25b smaller than the area of the upper opening 25a, and a slope portion 25c extending from the upper opening 25a to the lower opening 25b. The rectifying holes 22a are arranged so that the upper openings 25a are adjacent to each other. The thickness of the rectifying part 22 is 7.4 cm, the diameter is 160 cm, the opening area ratio of the rectifying hole 22a is 6.25% (the area of the upper opening 25a is 64 cm ² , and the area of the lower opening 25b is 4 cm ² ), and the slope The inclination angle of the portion 25c is 60 °. The water to be treated to be supplied to the flotation separation apparatus was previously mixed with a coagulant in a stirring tank and coagulated in a flock forming tank.
<Test conditions>
Untreated water flow rate: 40m ³ / hr
Daily average treated water turbidity: 2 to 5 degrees Flocculant used at the time of flocculation treatment: 10-20 mg / L of polyaluminum chloride (PAC) added Stirred tank residence time of treated water: 3 minutes Stirring strength in the stirring tank : 200s ^-1
Flock formation tank residence time of water to be treated: 6 minutes Stirring intensity in the flock formation tank: 40 s ⁻¹
Floating separation tank residence time of treated water: 8 minutes Flotation tank horizontal cross-sectional area: 1.94 m ²
Effective sectional area of floating tank (horizontal sectional area of floating tank excluding opening area of inflow part): 1.69 m ²
Processing speed for horizontal cross-sectional area of levitation tank: 20.6 m / h
Processing speed for effective sectional area of levitation tank: 23.7 m / h
Test time: 30 days continuous operation

(Comparative example)
As shown in FIG. 9, the rectifying unit used in the comparative example is arranged such that the upper openings are spaced apart from each other. Other than that, the test was performed under the same conditions as in the example.

  FIG. 7 is a diagram illustrating the results of the water turbidity to be treated and the water turbidity of Examples and Comparative Examples. As shown in FIG. 7, in the example, it was found that even in continuous operation for 30 days, the turbidity of the treated water did not rapidly increase and stable treatment was possible. In contrast, in the comparative example, the turbidity of the treated water increased rapidly twice during the 30-day continuous operation (3.2 degrees and 4.8 degrees), and the treatment was stable in the 30-day continuous operation. Could not do. In the rectifying unit of the embodiment, since the upper opening (in addition, the upper openings are adjacent to each other) and the slope portion having a larger area than the lower opening are formed and the slope is formed, sediment is deposited on the rectifying unit or in the rectifying hole. This is the result that the sediment is prevented from being discharged from the floating tank together with the treated water.

It is a schematic cross section which shows an example of a structure of the floating separation apparatus which concerns on this embodiment. It is a model top view which shows an example of a structure of the rectification | straightening part used by this embodiment. It is a schematic cross section which shows an example of a structure of the rectification | straightening part in the AA line of FIG. It is a schematic cross section which shows another example of a structure of the rectification | straightening part in the AA line of FIG. (A)-(C) are model perspective views which show the structure of a division | segmentation cell. It is a schematic cross section which shows an example of a structure of the floating separation apparatus which concerns on other embodiment of this invention. It is a figure showing the result of the to-be-processed water turbidity and the treated water turbidity of an Example and a comparative example. It is a schematic diagram which shows the structure of the floating separation apparatus of patent document 1. It is a schematic cross section which shows the structure of the rectification | straightening part used with the floating separation apparatus of patent document 1.

Explanation of symbols

  1-3 Floating separator 10, 60 Floating tank, 10a, 60a Perimeter wall, 10b Bottom part, 10c Water collecting part, 12 Inflow part, 14 Discharge part, 18 pit, 19 Sediment discharge pipe, 20a, 67a Upper part, 20b, 67b Lower part, 22, 70 Rectification part, 22a, 70a Rectification hole, 23 Floating object, 24 Floating object pot, 25a, 71a Upper opening part, 25b, 71b Lower opening part, 25c Slope part, 26 Guide tube, 26a, 28a opening 27, split cell, 28 inlet pipe, 30, 72 treated water inflow pipe, 32,74 pressurized water inflow pipe, 38 treated water takeout pipe, 40 water level adjustment tank, 41 movable weir, 42,76 treated water discharge pipe, 44 Material discharge pipe, 50 levitated skimmer, 52 sediment scraper, 54 motor, 56 support, 62a, 62b partition, 64 first chamber, 6 6 Second chamber, 68 Third chamber, 75 air dissolution tank, 78 pump, 80 communication pipe.

Claims (9)

A levitation separation device that attaches bubbles to a substance to be treated in the water to be treated and separates the substance to be treated as a floating substance,
A floating tank, a rectifying section that divides the floating tank into an upper part and a lower part in a vertical direction, an inflow part that allows treated water to flow into the upper part, and treated water from which the treated substance is separated is collected from the lower part. A water collecting section,
The rectifying unit includes a plurality of rectifying holes for passing the treated water.
The rectifying hole includes an upper opening, a lower opening smaller than an area of the upper opening, and a slope portion extending from the upper opening to the lower opening.   The levitation separator according to claim 1, wherein the rectifying holes are arranged so that upper openings are adjacent to each other.   The levitation separator according to claim 1, wherein the slope portion has an inclination angle in a range of 45 ° to 75 °.   The levitation separation apparatus according to claim 1, wherein the rectification unit includes a plurality of divided cells, and the divided cells include at least one rectification hole.   2. The floating separator according to claim 1, wherein the area of the lower opening with respect to the area of the upper opening is in the range of 2 to 10%.   It is a floating separation apparatus of any one of Claims 1-5, Comprising: The said floating tank is cylindrical shape, The floating separation apparatus characterized by the above-mentioned. A rectifier that divides a levitation tank of a levitation separator that separates a substance to be treated as a levitated substance into upper and lower parts in a vertical direction by attaching bubbles to the substance to be treated in the treatment water,
The rectifying device includes a plurality of rectifying holes for passing treated water,
The rectifying hole includes an upper opening, a lower opening smaller than an area of the upper opening, and a slope portion extending from the upper opening to the lower opening.   8. The rectifying device according to claim 7, wherein the rectifying device includes a plurality of divided cells, and the divided cells include at least one or more rectifying holes. A splitting cell for a rectifying device that constitutes a rectifying device that divides a floating tank of a levitation separator that vertically separates a floating substance into a floating material by attaching bubbles to the material to be treated in the water to be treated, and separating the material to be treated as a floating substance. ,
The division cell for the rectifier includes at least one rectifying hole through which treated water flows,
The rectifying hole has an upper opening, a lower opening smaller than an area of the upper opening, and a slope portion extending from the upper opening to the lower opening. .

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