JP2019030878A - Sedimentation tank and sedimentation treatment method - Google Patents

Abstract

To provide a sedimentation tank where the treatment of water to be treated is efficiently performed by accelerating the sedimentation of flocks suppressing the wind-up of sludge in the sedimentation tank.SOLUTION: According to an embodiment, a sedimentation tank 10 for settling and separating flocks contained in water to be treated includes: a columnar or polygonal columnar tank body 11; an inflow pipe 12 supplying the water to be treated below the tank body 11 toward an axial direction in the tank body 11; and a plurality of guide blades 13 changing the flow of the water to be treated so that the water to be treated supplied into the tank body 11 becomes a swirl flow.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a precipitation tank and a precipitation treatment method.

  In recent years, effective use of water resources is required due to industrial development and population growth. For that purpose, reuse of wastewater such as industrial wastewater is very important. In order to achieve these, it is necessary to purify the water, ie to separate other substances from the water.

  One method for separating fine suspended solids (SS) from a liquid is a sedimentation separation method. In order to improve the separation efficiency of suspended solids in the sedimentation separation method, it is important to generate a uniform upward flow at a low speed in a rectangular or circular sedimentation tank. Therefore, a sedimentation tank has been developed in which the raw water lowered from the feed well is used as an upward flow and overflows from the upper part of the sedimentation tank.

  However, in such a settling tank, when the treated water is supplied into the tank, the sludge accumulated at the bottom of the settling tank may roll up, and the quality of the treated water cannot be improved beyond a certain level, There were problems such as long processing time.

  On the other hand, in such a sedimentation tank, a mechanism is known in which raw water flowing from a feed well is converted into a uniform upward flow while effectively suppressing sludge winding. As such a mechanism, a mechanism provided with a plate for changing the flow of water against the lower end of the feed well is known. By providing the plate, the raw water forms a collision jet on the upper surface of the plate and flows out in the horizontal direction. In this settling tank, an upward flow is then formed on the tank wall surface as the main flow, and the clarified water flows out through the inclined plate.

  In this method, since the raw water outflow angle is in the horizontal direction, it is difficult to generate sludge at the bottom of the sedimentation tank, and the effect of improving the quality of the treated water is obtained, and at the same time, the raw water outflow part is set at a lower position, The effect of enabling the height to be reduced is obtained. In addition, since the mainstream passes near the tank wall surface, the inclined plate installed near the tank wall surface has a greater effect and suppresses leakage of suspended solids.

  In such a sedimentation tank, in order to effectively form flocs, a technique having a rotating blade for stirring raw water in a raw water supply pipe is known.

Japanese Patent Laid-Open No. 10-165714 JP 2006-28159 A JP 2008-246282 A JP-A-11-169609 JP 2002-58910 A

  The problem to be solved by the present invention is a sedimentation tank with a simple apparatus configuration, which suppresses the winding of sludge and promotes sedimentation of flocs, thereby efficiently treating treated water and It is to provide a precipitation processing method.

  The sedimentation tank of the embodiment is a sedimentation tank for precipitating and separating flocs contained in the water to be treated, and has a cylindrical or polygonal columnar tank body, and the tank body is directed downward in the axial direction of the tank body. An inflow pipe for supplying the water to be treated, and a plurality of guide blades for changing the flow of the water to be treated so that the water to be treated to be supplied into the tank forms a spiral flow. Features.

  The sedimentation treatment method of the embodiment is a sedimentation treatment method using the sedimentation tank, and supplies water to be treated containing floc from the inlet of the inflow pipe into the tank so as to form a spiral flow. A treated water supply step, a floc settling step for settling flocs contained in the treated water while circulating the treated water supplied into the tank, and the flocs settled in the flock settling step And a precipitation step of precipitating at the bottom of the tank body.

It is sectional drawing which shows schematic structure of the sedimentation tank in 1st Embodiment. It is sectional drawing which looked at the inflow pipe and guide blade of the sedimentation tank shown in FIG. 1 from the plane direction. In the settling tank shown in FIG. 1, it is the figure which showed the flow of the to-be-processed water in an inflow pipe. It is an expansion perspective view which shows the modification of the guide blade in 1st Embodiment. It is sectional drawing which shows schematic structure of the sedimentation tank in 2nd Embodiment. It is sectional drawing which shows schematic structure of the sedimentation tank in 3rd Embodiment. It is a top view of the to-be-processed water distribution mechanism in 3rd Embodiment. It is a top view which shows the modification of the to-be-processed water distribution mechanism in 3rd Embodiment. It is a perspective view which shows the other modification of the to-be-processed water distribution mechanism in 3rd Embodiment. It is a perspective view which shows the further another modification of the to-be-processed water distribution mechanism in 3rd Embodiment. It is sectional drawing which shows schematic structure of the sedimentation tank in 4th Embodiment. It is a perspective view of the to-be-processed water distribution mechanism in 4th Embodiment. It is a perspective view which shows the modification of the to-be-processed water distribution mechanism in 4th Embodiment.

  Hereinafter, the sedimentation tank in the present embodiment will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a schematic configuration of the settling tank in the first embodiment, and FIG. 2 is a cross-sectional view of the inflow pipe and guide vanes of the settling tank shown in FIG. FIG. 3 is a view showing the flow of water to be treated in the inflow pipe in the settling tank shown in FIG.

  As shown in FIG. 1, the sedimentation tank 10 of 1st Embodiment is arrange | positioned in the inside of the tank body 11, the tank body 11, and the inflow pipe 12 which supplies to-be-processed water in this tank body 11, The to-be-processed water supplied in the tank body 11 is provided with the some guide blade 13 which changes the flow of to-be-processed water so that it may become a spiral flow.

  In addition, as shown by an arrow in the drawing, the upper end portion of the tank body 11 is provided with piping for supplying water to be treated into the tank body 11 through the inflow pipe 12 from the outside, and further, floc separation (described below) An overflow weir 14 and an outflow pipe 15 are provided for discharging treated water obtained by carrying out the (precipitation) removal operation.

  The tank body 11 is a tank having a columnar or polygonal column shape. This tank body 11 is a container comprised by the wall surface and the bottom face, and while storing a to-be-processed water inside, it is possible to precipitate a flock. The tank body 11 is arranged so that the central axis of the tank body 11 coincides with the vertical direction so that the flow of water to be treated stored therein can be made uniform in a predetermined direction. At this time, the outer shape of the wall surface of the tank body (the shape when viewed from the upper side or the lower side in the figure) when the tank body 11 is viewed in plan is a circular shape or a polygonal shape. The polygonal shape may be a rectangular shape such as a square or a rectangle, or may be a pentagonal or higher polygonal shape.

  As will be described later, it is preferable that the water to be treated flows in the tank body 11 as evenly as possible in order to precipitate the flocs efficiently. Therefore, it is more preferable that the shape of the tank body 11 is a perfect circle if it is a circular shape, and a regular polygon if it is a polygonal shape.

  Moreover, it is preferable that the bottom part of the tank body 11 is a shape where the center of the bottom part was dented so that a sediment could be settled and recovered efficiently. As such a recessed shape, a shape in which a conical shape or a polygonal pyramid shape is turned upside down is more preferable. That is, the shape is such that the bottom center is the apex of the cone and the lowest part. And in the lowest part of the bottom part of this tank body 11, the discharge port is provided so that a deposit can be discharged | emitted outside the tank body 11, and the sludge extraction pipe | tube 16 is arrange | positioned by the discharge port.

Moreover, the magnitude | size of the tank 11 can be arbitrarily adjusted according to the quantity of the to-be-processed water which should be processed. Examples of the size of the tank body 11 include those having a capacity of 6 to 880 m ³ , an inner diameter of 2 to 15 m, and a height of 2 to 5 m.

  The inflow pipe 12 is disposed so that the inflow port 12 a of the water to be treated is provided inside the tank body 11. And the to-be-processed water supplied from this inflow pipe 12 is supplied in the tank body 11 toward the axial direction downward direction of the tank body 11 from the inflow port 12a. That is, the inflow port 12 a is located at the center of the outer shape of the tank body 11 in the plan view of the tank body 11 and is provided toward the bottom of the tank body 11.

  Further, the inflow port 12a is preferably provided at a position lower than the central portion in the height of the straight body portion of the tank body 11. By providing at this position, it is possible to sufficiently form an upward flow in the tank of water to be treated which will be described later. In the present specification, the “straight barrel portion” refers to a wall surface portion formed in a cylindrical shape of the tank body 11 and does not include the bottom portion.

  The size of the inflow pipe 12 depends on the supply amount of the water to be treated, and may be appropriately selected depending on the size of the tank body 11 and the like. As the diameter of the inflow pipe 12, for example, a pipe having an inner diameter of 0.1 to 0.4 times the inner diameter of the tank body 11 is preferable.

  Further, a scraping shaft 17 is disposed at the center of the inflow pipe 12. The scraping shaft 17 is configured to rotate at the center of the tank body 11 by the drive motor 20. The scraping shaft 17 is connected to a support member 18 positioned below the scraping shaft 17, and a plurality of scraping plates 19 are suspended from the support member 18 downward (bottom of the tank body).

  The scraping shaft 17, the support member 18, the scraping plate 19 and the drive motor 20 constitute a scraping mechanism, and the scraping mechanism, as will be described below, removes the precipitate after treatment of the water to be treated. It can be scraped to the vicinity of the discharge port located in the center of the bottom of the. The squeezed precipitate is configured so that the precipitate can be discharged to the outside of the tank body 11 from the discharge port.

  The guide vane 13 is a member for supplying the water to be treated supplied from the inflow pipe 12 into the tank body 11 as a spiral flow. It is not particularly limited as long as it can form a spiral flow, and may have any shape and form, but is configured by a plurality of plate-like bodies that can change the flow direction of the water to be treated supplied from the inflow pipe 12. It is preferable. This plate-like body may be fixed inside the inflow pipe 12 or fixed near the inflow port 12a so that the flow direction can be changed immediately after the supply from the inflow port 12a into the tank body 11.

  1 and 2 show an example in which four guide vanes 13 fixed to the inner wall surface of the inflow pipe 12 are formed. These guide vanes 13 are provided at the same height and inclined with respect to the vertical plane passing through the axis of the inflow pipe 12. Further, the inclination of the guide vane 13 is provided to be inclined in the same direction when viewed from the center (axis) of the inflow pipe 12. If the inclination directions are different, it becomes difficult to generate a spiral flow stably.

  Furthermore, it is preferable that the plurality of guide blades 13 are provided at a uniform inclination angle. Further, as shown in FIG. 2, it is preferable that the guide vanes 13 are arranged evenly in the inflow pipe 12 when viewed in plan. Thus, a stable spiral flow can be generated in the inflow pipe 12 by making the inclination direction, the inclination angle, and the arrangement position uniform and uniform.

  In addition, the inclination angle θg of the guide vane 13 is preferably about 10 ° to 60 ° with respect to the vertical line when viewed from the axis of the inflow pipe 12, for example, about 20 ° to 50 °. More preferably, it is more preferably about 30 ° to 40 °. At this time, as the angle with respect to the vertical line is increased (closer to 90 °), the water to be treated supplied into the tank body 11 flows with a larger force in the horizontal direction than in the vertical direction. In that case, it is possible to suppress the rolling up of the sludge containing flocs precipitated at the bottom of the tank body 11 by the water to be treated.

  1 and 2 show an example in which four guide vanes 13 are provided, but the number is not particularly limited as long as a spiral flow can be generated. The number of guide vanes 13 provided can be set as appropriate depending on the inner diameter and length of the inflow pipe 12, the flow rate of the water to be treated, the shape and inclination angle of the guide vanes 13, and the like. For example, when the inner diameter of the inflow pipe 12 is 1 m, it is preferable to provide about 8 to 12 guide vanes 13 in the circumferential direction of the inner diameter, and the number of the guide vanes 13 is increased as the inner diameter of the inflow pipe 12 is increased. Is preferred. By doing in this way, the pressure concerning one guide blade can be disperse | distributed and a to-be-processed water can be supplied stably.

  1 and 2, the fan-shaped and flat guide blades 13 are shown so as to be fixed to the inner wall of the cylindrical inflow pipe 12. However, the shape is not particularly limited as long as a spiral flow can be generated. Further, the arrangement of the guide vanes 13 is also not particularly limited as long as it can generate a spiral flow in FIGS.

  For example, in addition to the guide vanes shown in FIG. 1 and FIG. 2, a plurality of flat guide vanes may be arranged in the same manner by changing the height in the vertical direction to obtain a guide vane having a multi-stage arrangement. it can. At this time, a plurality of flat guide blades having different heights can be arranged so as to function as one guide blade. That is, it is also possible to make a multistage arrangement as if the main surfaces of the vertical surface passing through the axis of the inflow pipe 12 form a continuous inclined surface. Furthermore, when arranging in multiple stages, it is also possible to connect and arrange flat guide blades of different heights and actually configure as one guide blade.

  Also, when multiple flat guide vanes are arranged in multiple stages as one guide vane, the angle of each guide vane is arranged so that the flow direction of the water to be treated is gradually changed from the vertical direction to the horizontal side. You can also That is, the inclination angle θg of the plurality of guide blades is increased stepwise from the guide blade that first collides with the water to be treated (the farthest from the inlet 12a) to the guide blade that is closest to the inlet 12a. It is only necessary that the flow direction of the water to be treated can be guided while gradually changing from the vertical direction to the horizontal direction.

  Moreover, although the above demonstrated the case where a plate-shaped guide blade was used, it comprised with the curved-plate-shaped guide blade which has a curved surface which changes an angle of the flow direction of to-be-processed water from a vertical direction to a horizontal direction side gradually. You can also. Also in this case, it may be a one-stage arrangement arranged in a line in the horizontal direction, or a plurality of guide vanes as a multi-stage arrangement so that it functions as one guide vane or actually with one guide vane. You may arrange | position and comprise so that it may become.

  The overflow weir 14 is for obtaining treated water obtained by performing a sedimentation process of flocs in the tank body 11 and purifying the water to be treated, and is provided on the upper part of the tank body 11. The overflow weir 14 is provided in a groove shape in the tank body 11 and generally along the wall surface of the tank body 11 so that the treated water overflowing from the upper end portion can be accommodated. Then, the treated water stored in the overflow weir 14 is caused to flow out of the tank body 11 through the outflow pipe 15. The treated water thus obtained is sent to the use point by performing other treatments.

  The sludge extraction pipe 16 is a discharge pipe that discharges sludge that has settled and stayed at the bottom of the tank body 11 to the outside of the tank body 11. This sludge is a mixture in which the floc settles in the tank body 11 and settles. This sludge is produced by rotating the scraping shaft 17 of the scraping mechanism disposed at the bottom of the tank body 11 by the drive motor 20 and rotating the scraping plate 19 suspended from the support member 18 (at the bottom). ).

  Furthermore, the sedimentation tank 10 may be provided with a shelf plate 21 for increasing the sedimentation efficiency of flocs in the water to be treated. The shelf plate 21 is provided at a height at which the water to be treated supplied from the inflow pipe 12 flows as an upward flow along the wall surface of the tank body 11 in a state where the main surface is parallel or inclined with respect to the horizontal plane. . The shelf plate 21 is provided in an annular shape in the circumferential direction of the inner wall surface of the tank body 11. In the present specification, the annular shape may be formed by one annular plate member (shelf plate 21), or a plurality of fan-like plate members (shelf plate 21) are aligned on a horizontal plane. And may be formed. When using a plurality of fan-shaped flat members (shelf plates 21), they may be arranged so that a gap is formed between the shelf plates 21 in the circumferential direction of the inner wall surface.

  In addition, when the plurality of shelf boards 21 are arranged so that there is a gap between the shelf boards, another shelf board is provided at a predetermined interval above or below the gap in the vertical direction. The shelf board is preferably provided in multiple stages. That is, another shelf board is provided in the vertical direction with respect to the gap between the shelf boards of the same height. Furthermore, the shelf boards are preferably formed so that the shelf boards formed at different heights overlap when viewed in plan (i.e., the shelf boards formed in the same plane when viewed in plan). The shelf plates provided at different heights than the gaps are formed in a shape that is longer in the circumferential direction, and the shelf plates at different heights are always provided in the vertical direction of the gaps). By adopting such a configuration, the water to be treated that has risen in the tank body 11 can change the flow direction by the shelf plate 21, and the flocs in the water to be treated that has become the upward flow can thereby be settled. Can promote.

  The shelf plate 21 is preferably fixed in contact with the inner wall surface of the tank body 11. Moreover, although the main surface of the shelf board 21 may be installed in parallel with the horizontal plane, the horizontal plane is such that the center side (inner peripheral side) exists below the wall surface side (outer peripheral side) of the tank body 11. And may be installed so as to form a predetermined inclination angle θs. In the case of installation with an inclination, the inclination angle θs is preferably set in a range of 30 ° to 70 °, for example.

  The tank body 11, the inflow pipe 12, the guide vane 13, the shelf plate 21, etc. that constitute the settling tank 10 can be made of any material. However, when handling corrosive water to be treated, stainless steel, plastic In addition, it can be made of a resin coating material obtained by coating a metal plate such as a general structural rolled steel (SS400) with an epoxy resin-based resin material, and is made of stainless steel particularly when strength is required.

  Further, the “floc” in the present embodiment means a lint-like lump that is produced when, for example, a flocculant is added to the water to be treated containing suspended solids.

  Next, a method for precipitating water to be treated using the sedimentation tank 10 shown in FIGS. 1 and 2 will be described. First, when the water to be treated containing flocs having sedimentation properties flows into the inflow pipe 12, the water to be treated flows through the inside of the inflow pipe 12, and is supplied into the tank body 11 from the inlet 12a. The inside of the tank body 11 will be filled.

  As shown in FIG. 3, the water to be treated that is continuously supplied collides with guide vanes 13 (not shown in FIG. 3) in the inflow pipe 12, and the flow direction is changed obliquely downward. The water to be treated whose flow direction has been changed proceeds downward while being spiraled (spiral flow) in the inflow pipe 12 as shown by the arrows in FIG. In addition, in FIG. 3, in order to make it easy to understand the flow of to-be-processed water, the flow is shown with the continuous line and the broken line.

  Thus, when the water to be treated that has become a spiral flow in the inflow pipe 12 is supplied to the tank body 11, it is supplied in a spiral form obliquely downward from the center of the tank body 11 toward the wall surface of the tank body 11. Is distributed. At this time, by using a spiral flow, the flow velocity in the vertical direction can be reduced as compared with the case where the gas is supplied downward in the vertical direction. By reducing this flow rate, it is possible to suppress the winding of sludge containing flocs that have settled and deposited on the bottom of the tank body 11. Moreover, since the force to move to the horizontal direction works at the time of supply by making it into a swirl flow, it is easy to disperse | distribute to the wall surface direction of the tank body 11, Furthermore, it is until it reaches the wall surface of the tank body 11 The distance can be increased, and floc formation and precipitation can be effectively promoted.

  The treated water supplied into the tank body 11 flows in the direction of flow toward the wall surface of the tank body 11, and a part of the treated water that has reached the wall surface of the tank body 11 is the inner wall surface of the tank body 11. Rises along the other, and some others go down. The flocs contained in the upward flow settle while being formed into a lump with the nearby flocs, and the flocs contained in the downward flow settle as they are. The flocs that have settled down in this manner stay in the lower part of the tank body 11 as sludge.

  The water to be treated that forms an upward flow rises to the water surface along the wall surface of the tank body 11, then changes the flow from the wall surface of the tank body 11 toward the center near the water surface, and further becomes a downward flow near the inflow pipe 12. It circulates in the tank body 11.

  In this way, the floc that has settled in the water to be treated stays (precipitates) at the bottom of the tank body 11 as in the conventional case, and is collected near the discharge port by a scraping mechanism as necessary, and the sludge extraction pipe 16 is collected. Discharged from.

  Therefore, according to the present embodiment, it is possible to perform the precipitation process while suppressing the winding up of the sludge once retained at the bottom of the tank body 11. Therefore, the treated water can be efficiently purified by floc sedimentation, and treated water with improved water quality can be obtained.

  On the other hand, sludge accumulated in the bottom of the tank body 11 and floc lump are discharged as a sludge mixture in the center of the bottom part of the tank body 11 by a scraping mechanism disposed at the bottom of the tank body 11. Collected in the vicinity of the outlet and discharged to the outside by a sludge extraction pipe 16 connected to the outlet.

  Through the above operation, the treated water from which the floc is separated and removed from the water to be treated including the floc supplied into the sedimentation tank 10 is overflow overflow weir 14 disposed in the upper part of the tank body 11. And are discharged to the outside through the outflow pipe 15. The treated water thus purified is further subjected to a predetermined treatment or the like and supplied to a use point.

  As described above, in the present embodiment, the flow of the water to be treated supplied into the tank body 11 is merely a simple tank structure in which the plate-shaped guide blades 13 are disposed. The separation (precipitation) efficiency of flocs can be effectively increased, and a precipitation tank in which simplification of the internal structure of the tank and improvement of the precipitation efficiency can be provided.

  In addition, although the above-mentioned guide blade 13 is an example fixed to the inner wall surface of the inflow pipe 12, these arrangements and configurations can be variously modified as long as the water to be treated can be supplied into the tank body 11 by a spiral flow. Can also be added.

  For example, FIG. 4 is a perspective view showing a modification of the guide blade. The guide vane 23 shown in FIG. 4 is an example fixed to the scraping shaft 17 instead of the inflow pipe 12. When the guide blade 23 is provided on the scraping shaft 17, the guide shaft 23 rotates simultaneously because the scraping shaft 17 rotates in the axial direction. Therefore, in this case, in addition to the inclination of the guide vanes 23, a force that causes a swirl of the water to be treated also acts by the rotational force. Therefore, the inclination of the guide vane 23 may be gentler than when it is fixed to the inner wall surface of the inflow pipe 12 shown in FIGS.

  At this time, the inclination of the guide vanes 23 and the rotation of the scraping shaft 17 are configured to generate a spiral flow in the same direction. If this is the opposite direction, they may cancel each other out, making it difficult to create a swirl flow.

  Furthermore, it is preferable to provide the shelf board 21 also on the inner wall surface of the tank body 11 at this time. If this shelf board 21 is provided, the water to be treated that rises along the inner wall surface of the tank body 11 will collide with the shelf board 21 after supply, and the direction of flow along the lower surface of the shelf board 21 will be obliquely upward. change. On the other hand, when the water to be treated collides with the shelf plate 21, the flocs contained in the water to be treated are disturbed in flow and flocs form a lump, and the flocs are promoted to settle.

  Further, the flocs contained in the water to be treated that have not settled down due to the collision with the shelf board 21 and the flow direction is obliquely upward and the upward flow is in a lump with the nearby flocs above the shelf board 21. It sinks while. At the time of the sedimentation of the floc, the floc starts to settle above the shelf 21 due to the influence of the upward flow, and settles on the upper surface of the shelf 21. Further, flocs further accumulate on the upper surface of the shelf plate 21, and when a certain amount of flocs accumulates, the block of flocs collapses to the bottom of the tank body 11.

  When the shelf plate 21 is installed on a horizontal plane, the degree of collapse differs depending on the manner of floc accumulation and the like, and the variation in the size of the floc that settles to the bottom of the tank body 11 is large. At this time, if the bulk of flocs with a large accumulation amount collapses, the sludge staying at the bottom of the tank body 11 may be wound up. On the other hand, when the shelf board 21 is inclined with respect to the horizontal plane, the collapse of the block of flocs is accelerated as compared with the case where the shelf board 21 is provided on the horizontal plane, and the amount of floc deposited on the shelf board 21 is reduced. Can be suppressed. And the influence which it has on the rolling-up of the sludge which stayed in the bottom part of the tank 11 can also be suppressed by suppressing the enlarging of the block of the floc sliding down from the shelf board 21 in this way. Further, when the inclination angle θs of the shelf board 21 is increased, the floc lump can roll down the upper surface of the shelf board 21, and the floc is stably settled to the bottom of the tank body 11. Can do.

  Further, when a plurality of the shelf boards 21 are arranged on the same horizontal plane and arranged so that there is a gap between the shelf boards in the circumferential direction of the inner wall surface, as described above, the vertical direction of these gaps is In any case, it is preferable to provide another shelf board with a predetermined interval and to provide the shelf board in multiple stages. In this case, in order to efficiently separate the flocs, the shelves formed on different horizontal planes overlap when viewed in plan (in a different stage than the gap between the shelves formed on the same plane. It is preferable to arrange the shelf plates so that the shelf plates are formed in a shape that is long in the circumferential direction, and other shelf plates are always provided in the vertical direction of the gap.

  At this time, it is more preferable to make the overlap of the shelf boards formed in different horizontal planes as large as possible. However, if the overlapping part is too large, the flow direction of the upward flow will change abruptly and turbulence will occur, or if the vertical distance between the shelves provided on different horizontal surfaces is too small , Flock will be wound up in the upward flow, or easier to do. Even if these shelf boards are inclined, the same state is obtained. Therefore, a plurality of the shelf boards 21 are aligned on the same horizontal plane and arranged so that there is a gap between the shelf boards in the circumferential direction of the inner wall surface, and a predetermined interval is provided either above or below the gap in the vertical direction. When another shelf plate is provided and the shelf plates are provided in multiple stages, it is required to appropriately set conditions so that the flocs can sufficiently settle.

[Second Embodiment]
FIG. 5 is a cross-sectional view showing a schematic configuration of a sedimentation tank in the second embodiment.

  As shown in FIG. 5, the sedimentation tank 30 of the second embodiment includes a tank body 11, an inflow pipe 12 that is disposed inside the tank body 11 and supplies water to be treated into the tank body 11, A plurality of guide blades 13 that change the flow of the water to be treated so that the water to be treated supplied into the tank body 11 becomes a spiral flow, and the inflow pipe 12 are disposed below and supplied to the tank body 11. The treated water distribution mechanism 31 disperses the treated water in the horizontal direction by the collision with the treated water.

  Here, the same components as those in the first embodiment are denoted by the same reference numerals and will not be described below. Therefore, the settling tank 30 in the second embodiment shown in FIG. 5 is provided with the water distribution mechanism 31 to be treated below the inlet 12a in the settling tank 10 of the first embodiment shown in FIG. The precipitation tanks have the same configuration except for the difference.

  The treated water distribution mechanism 31 disperses the treated water supplied from the inflow pipe 12 in the horizontal direction. As shown in FIG. 5, the to-be-processed water distribution mechanism 31 is comprised from one dispersion | distribution plate. The planar shape is not particularly limited, but is preferably similar to the outer shape when the tank body 11 is viewed in plan. That is, it is preferably a circle, an ellipse or a polygon.

  The diameter of the planar shape or the length of one side of the treated water distribution mechanism 31 is not less than the diameter of the inflow pipe 12 and is preferably 1 to 3 times the inner diameter of the inflow pipe 12.

  The treated water distribution mechanism 31 may be composed of a plurality of dispersion plates. When using a plurality of dispersion plates having a circular outer shape, prepare a circular dispersion plate having the same outer diameter and an annular dispersion plate with an opening at the center. There is an example in which the annular dispersion plates are spaced apart from each other and aligned and fixed in the vertical direction. At this time, a circular dispersion plate having no opening is provided at the lowermost stage so that the opening becomes smaller from the upper dispersion plate toward the lower dispersion plate. Further, the opening and the center are formed concentrically around the axis of the inflow pipe 12, that is, the scraping shaft 15.

  The outer diameters of the plurality of dispersion plates are not less than the diameter of the inflow pipe 12 and are preferably 1 to 3 times the inner diameter of the inflow pipe 12. Further, for example, when using a total of three dispersion plates, two annular dispersion plates and one circular dispersion plate, the diameter of the opening provided in the uppermost dispersion plate is, for example, the inflow pipe The diameter of the opening 12 provided in the second dispersion plate from the top is 0.5 to 0.6 times the diameter of the inflow pipe 12. be able to. And let the lowermost dispersion | distribution plate be a circular thing in which the opening part is not formed.

  In this way, by decreasing the diameter of the openings in order from the dispersion plate located above to the dispersion plate located below, the supplied water to be treated has a flux in order from the outer peripheral side. It will collide with each dispersion plate. The water to be treated that collides with the dispersion plate is evenly dispersed in the horizontal direction on the outer peripheral side. Further, at this time, since the dispersion is performed stepwise by each dispersion plate, the load is less than that of changing the flow of water to be treated by colliding at a time, and can be efficiently dispersed.

  The dispersion plate constituting the treated water distribution mechanism 31 is held and fixed by the holding member so as to have a predetermined positional relationship. For example, the positional relationship with the inflow pipe 12 is also related to the action and effect, and each dispersion plate is preferably arranged and fixed so that the center (axis) of the inflow pipe 12 coincides in the vertical direction. Therefore, the treated water distribution mechanism 31 is preferably fixed to the inflow pipe 12. Moreover, when the above-mentioned to-be-processed water distribution mechanism 31 comprises a plurality of dispersion plates, the number of the dispersion plates is preferably about 3 to 5.

  According to the second embodiment, the water to be treated supplied from the inflow pipe 12 does not flow in the bottom part direction of the tank body 11 and the flow is changed in the horizontal direction. Can be prevented. In addition, since the supplied water to be treated is a spiral flow, the flow velocity of the water to be treated which has collided with the dispersion plate and became a jet flow can be reduced compared to the case where it is supplied downward in the vertical direction. By reducing the flow velocity, it is possible to suppress the surrounding flocs from being rolled up. Further, by colliding with the dispersion plate as a swirl flow, the distance until reaching the wall surface of the tank body 11 can be increased, and the flocs until reaching the wall surface of the tank body 11 after colliding with the dispersion plate can be increased. Formation and precipitation can also be promoted, and the treatment water can be effectively cleaned.

[Third Embodiment]
FIG. 6 is a cross-sectional view showing a schematic configuration of a sedimentation tank in the third embodiment, and FIG. 7 is a plan view of the water distribution mechanism for the sedimentation tank shown in FIG.

  As shown in FIGS. 6 and 7, the sedimentation tank 40 of the third embodiment is disposed inside the tank body 11 and the tank body 11, and an inflow pipe for supplying water to be treated into the tank body 11. 12 and a to-be-treated water distribution mechanism 41 that is disposed below the inflow pipe 12 and disperses the to-be-treated water in the horizontal direction by collision with the to-be-treated water supplied into the tank body 11.

  Here, about the same structure as 1st Embodiment and 2nd Embodiment, the same code | symbol is attached | subjected and it abbreviate | omits in the following description. The sedimentation tank 40 in the third embodiment shown in FIG. 6 is the same as the sedimentation tank 30 in the second embodiment shown in FIG. It is a settling tank in which a treated water distribution mechanism 41 is provided instead of the distribution mechanism 31.

  In the treated water distribution mechanism 41, the treated water supplied into the tank body 11 collides so that the dispersion plate 41a that changes the flow in the horizontal direction and the treated water that changes the flow in the horizontal direction form a spiral flow. And a plurality of guide blades 41b for guiding the flow of water to be treated. In the third embodiment, the water to be treated is supplied to the tank body 11 without being a spiral flow in the inflow pipe 12. The water to be treated supplied to the tank body 11 is dispersed in the horizontal direction by the collision with the dispersion plate 41a, the flow direction is changed by the guide blade 41b, and a spiral flow is formed.

  In FIG. 7, the top view of the to-be-processed water distribution mechanism 41 in the settling tank shown in FIG. 6 is shown. Here, the to-be-treated water distribution mechanism 41 includes a dispersion plate 41a and a plurality of guide blades 41b. As the dispersion plate 41a, the treated water distribution mechanism 31 described in the second embodiment can be applied as it is. That is, it may be composed of a single plate or a plurality of plates.

  Further, the guide blade 41b is formed of a rectangular plate-like body, and a plurality of the guide blades 41b are vertically arranged on the upper surface of the dispersion plate 41a. At this time, as shown in FIG. 7, the guide vane 41 b is provided with its main surface inclined with respect to a vertical plane passing through the axis of the inflow pipe 12. That is, the guide blades 41 b are provided at different angles so that the extension line in the horizontal direction does not pass through the center position of the treated water distribution mechanism 41. In other words, when the inflow pipe 12 is viewed in plan, the radiation that diverges from its central axis and the main surface of the guide vane 41b are not parallel but have an angle. By providing the angle in this way, when the supplied water to be treated collides with the dispersion plate 41a and is dispersed in the horizontal direction (the wall surface direction of the tank body 11), the dispersion direction is changed by the guide blade 41b. The water to be treated whose direction has been changed becomes a spiral flow dispersed toward the outer periphery.

  The shape of the guide blade 41b is not particularly limited as long as a spiral flow can be formed, and various shapes and configurations can be mentioned. For example, as shown in FIG. 8, a guide vane 41c made of a curved plate having a radial curve shape from the center of the dispersion plate 41a to the outer periphery, or a plurality of plate-like members are connected as guide vanes. When the guide blades 41b are made into a single sheet, the angle of the plate-like body is shifted so as to increase from the center toward the outer periphery, and the spiral flow similar to the radial curve shape from the center of the dispersion plate 41a toward the outer periphery. And guide vanes that cause

  6 to 8 show the embodiment in which the dispersion plate 41a on the disk is a single sheet as the distribution mechanism 41 to be processed. However, as described in the second embodiment, a plurality of dispersion plates are used. You may comprise. In that case, it is preferable to provide the guide vane 41b, the guide vane 41c, etc. in each dispersion plate.

  9 and 10 illustrate a configuration in which guide vanes are provided on each dispersion plate, taking as an example the case where the water distribution mechanism to be treated is composed of two dispersion plates. Here, the two dispersion plates are composed of an upper dispersion plate 41A and a lower dispersion plate 41B, and are arranged with a predetermined interval in the vertical direction so that the center positions thereof coincide with the central axis of the inflow pipe 12. ing. At this time, the upper dispersion plate 41A is an annular plate having a hole through which the water to be treated flows at the center thereof, and the lower dispersion plate 41B is a disk without a hole through which the water to be treated flows. Shaped plate. A plurality of guide vanes 41b are provided on the upper surfaces of the respective dispersion plates so as to generate a spiral flow.

  When the treated water distribution mechanism having the plurality of dispersion plates 41A and 41B is used, when the treated water supplied from the inflow pipe 12 is supplied into the tank body 11, first the flux of the treated water is supplied. Among them, the outer peripheral portion collides with the dispersion plate 41A and flows in the horizontal direction. In addition, the inner peripheral portion of the flux of the water to be treated flows through the hole provided in the center of the dispersion plate 41A, and collides with the dispersion plate 41B, so that the water to be treated that has collided flows in the horizontal direction. Become.

  In the present embodiment, the water to be treated that flows in the horizontal direction on each dispersion plate is not dispersed radially as it is, but is guided by the guide vanes 41b to change the flow direction, resulting in a spiral flow. Dispersed in the body 11.

  FIG. 9 shows an example in which the spiral flow formed by both dispersion plates 41A and 41B is in the same direction (counterclockwise when viewed in plan), and FIG. 10 shows the dispersion plate 41A and the dispersion plate. Examples in which the spiral flow formed by 41B is in different directions (when viewed in plan, clockwise in the dispersion plate 41A and counterclockwise in the dispersion plate 41B) are shown. When the swirl flows in the same direction, the entire flow of the tank body 11 becomes a very slow and stable swirl flow. Therefore, from the treated water distribution mechanism 41 to the inner wall surface of the tank body 11 and further from the inner wall surface. As a rising flow, it is possible to increase the moving distance of the water to be treated to the overflow weir 14, and this has the advantage that the floc formation and sedimentation effect can be improved before the floc overflows from the upper end of the overflow weir 14. . On the other hand, when the swirl flows in different directions, there is an advantage that the effect of sedimentation of the flocs can be improved by promoting the formation of a block of flocs due to the mixed flow directions.

  In the present embodiment, the same effects and effects as in the second embodiment are achieved.

[Fourth Embodiment]
FIG. 11 is a cross-sectional view illustrating a schematic configuration of a sedimentation tank according to the fourth embodiment, and FIG. 12 is an enlarged perspective view illustrating a treated water distribution mechanism of the sedimentation tank illustrated in FIG.

  As shown in FIG. 11, the sedimentation tank 50 of the fourth embodiment includes a tank body 11, an inflow pipe 12 that is disposed inside the tank body 11, and supplies treated water into the tank body 11, A treated water distribution mechanism 51 disposed near the inlet of the inflow pipe 12 and having a flow dividing member that separates the flow of the treated water and a dispersion plate that disperses the separated treated water in the horizontal direction. It becomes.

  Here, the same components as those in the first to third embodiments are denoted by the same reference numerals and are omitted in the following description. Therefore, the settling tank 50 in the fourth embodiment shown in FIG. 11 is different from the settling tank 40 in the third embodiment shown in FIG. It is a sedimentation tank which is different in the point provided, and has the same structure other than that.

  The to-be-treated water distribution mechanism 51 disperses the to-be-treated water supplied from the inflow pipe 12 in the horizontal direction, and preferably has a configuration in which the to-be-treated water is evenly distributed so as not to generate a high-speed flow in the tank body 11. . In FIG. 12, an example of this to-be-processed water distribution mechanism 51 was shown. As shown in FIG. 12, the to-be-treated water distribution mechanism 51 includes a flow dividing member 51A, a dispersion plate 51B, and guide vanes 51C.

  In the treated water distribution mechanism 51, the flow dividing member 51A is composed of a flow dividing cylinder 51A-a mainly responsible for the function of dividing the water to be treated, and an annular dispersion plate 51A-b connected to the lower end thereof. It is configured. Therefore, in the treated water distribution mechanism 51 of FIG. 12, there are two dispersion plates that disperse the treated water in the horizontal direction, the dispersion plates 51A-b and the dispersion plate 51B.

  The dispersion plate 51A-b has an annular shape in which an opening is formed, and is integrally connected to the outer peripheral side of the lower end of the flow dividing cylinder 51A-a. That is, the water to be treated supplied from above is separated into two flows by the flow dividing cylinder 51A-a, and the water to be treated flowing inside the flow dividing cylinder 51A-a passes through the flow dividing pipe 51A-a as it is. Thus, it collides with the dispersion plate 51B. On the other hand, the water to be treated that flows outside the diversion tube 51A-a flows along the outer surface of the diversion tube 51A-a and collides with the dispersion plate 51A-b.

  In this way, the water to be treated that has collided with the dispersion plate 51A-b is dispersed at a high position, and the water to be treated that collided with the dispersion plate 51B is dispersed at a low position. The flow of this water to be treated is indicated by arrows in FIG.

  Thus, by separating the flow of the water to be treated by the flow dividing cylinder 51A-a, the supplied water to be treated collides with each dispersion plate in order from the outer peripheral side. The water to be treated that collides with the dispersion plate is dispersed in the horizontal direction toward the outer peripheral side. Further, since the dispersion is performed stepwise by each dispersion plate after the flow is divided, the load is less than that of changing the flow of the water to be treated by colliding at once, and the dispersion can be performed efficiently.

  As described above, the diversion tube 51A-a is a cylindrical member, and separates the flow of water to be treated supplied from the inflow pipe 12. Therefore, the diversion tube 51A-a is disposed in parallel with the inflow pipe 12 at the inflow port 12a of the inflow pipe 12 so as to efficiently divert the water to be treated. By arranging the flow dividing cylinder 51A-a in this way, the water to be treated can be smoothly separated into two flows inside and outside the flow dividing cylinder 51A-a without countering the flow.

  It is desired that the water to be treated thus separated is supplied into the tank body 11 so as to satisfy the preferable conditions for precipitation. If there is a part where the flow velocity is fast in the upward flow in the tank body 11, it may cause flocs to roll up, and the precipitation process itself may not be efficiently performed. Is preferably made as uniform as possible.

  Therefore, it is preferable to disperse the treated water dispersed from the treated water distribution mechanism 51 in the tank body 11 as uniformly as possible. In order to disperse in this way, for example, the water to be treated that collides with the dispersion plate 15A-b in FIG. 12 is as close to the center of the tank body 11 (near the outer periphery of the inflow pipe 12) as much as possible. If water is dispersed as much as possible on the outer peripheral side of the tank body 11 (in the vicinity of the wall surface of the tank body 11), the difference in the flow velocity of the upward flow generated in the tank body 11 can be reduced, and the flocs of the tank body 11 settle. Can be promoted.

  For example, the outer diameter of the diversion tube 51A-a is preferably 0.5 to 0.9 times the inner diameter of the inflow pipe 12, and more preferably 0.6 to 0.7 times. In addition, the outer diameters of the dispersion plates 51A-b and 51B, the distance between the inlet of the inlet pipe 12 and the dispersion plate 51A-b, and the dispersion plate 51A- What is necessary is just to set the space | interval of b, the dispersion | distribution plate 51B, etc. suitably.

  At this time, the outer diameter of the dispersion plate 51A-b is not less than the inner diameter of the inflow pipe 12, and is preferably 1 to 3 times the diameter of the inflow pipe 12. Further, the outer diameter of the dispersion plate 51B is not less than the inner diameter of the flow dividing cylinder 51A-a, and preferably 1 to 4 times the inner diameter of the flow dividing cylinder 51A-a.

  The dispersion plates 51A-b and the dispersion plate 51B are provided with guide vanes 51C on the upper surfaces thereof. That is, it has the same structure as the treated water distribution mechanism 41 used in the third embodiment, which is an example in which two dispersion plates shown in FIG. 9 are provided. A cylindrical member (distribution cylinder 51A-a) is additionally connected to the opening of the annular dispersion plate.

  Therefore, in the fourth embodiment, the same effect as in the third embodiment is achieved, and at the same time, the flow dividing tube 51A-a is connected to the dispersion plate 51A-b, so that the flow dividing tube 51A-a The flow of the water to be treated can be reliably divided and the flow of the water to be treated in the tank body 11 can be stabilized.

  The flow dividing member 51A and the dispersion plate 51B are held and fixed so as to be in a predetermined positional relationship by a holding member (not shown). Further, the water distribution mechanism 51 to be treated is arranged and fixed so that its center (axis) coincides with the vertical direction in relation to the action and effect of the positional relationship with the inlet 12a of the inflow pipe 12. Therefore, the treated water distribution mechanism 51 is preferably fixed to the inflow pipe 12.

  Further, as a modified example of the treated water distribution mechanism 51 using this diversion tube, as shown in FIG. 13, a treated water distribution mechanism 52, which is different from the treated water distribution mechanism 51 in the position where the guide blades are provided, is provided. Can be mentioned. The treated water distribution mechanism 52 is different in that a guide blade 52C is provided instead of the guide blade 51C of the treated water distribution mechanism 51.

  That is, the to-be-processed water distribution mechanism 52 is comprised from the flow dividing member 51A, the dispersion | distribution plate 51B, and the guide blade | wing 52C. The guide vane 52C is provided with a plate-like body inclined with respect to the vertical axis inside and outside the flow dividing cylinder 51A-a as in the case of the guide vane 13 described in the first embodiment. This is an example in which treated water becomes a spiral flow (spiral flow).

  In addition, although the to-be-processed water distribution mechanism 51 is an example comprised by one diverting member and one dispersion | distribution plate, two or more diversion members are provided, and to-be-processed water is divided and distributed finely in steps. You may make it make it. At this time, the number of installed flow dividing members is preferably about 1 to 3.

  Further, in the first to fourth embodiments described above, the form in which the water to be treated is swirled by the guide vanes has been described, but at this time, an opening or a slit may be formed in the guide vanes. Thus, by providing the opening in the guide vane, it is possible to adjust the amount of water to be treated that changes the flow direction by colliding with the guide vane, or to adjust the load applied to the guide vane.

  In addition, it is preferable to provide an opening or a slit so that the load applied to the guide vanes is as uniform as possible. In order to equalize the load, for example, it is conceivable that the positions where the openings or slits are provided in the plurality of guide blades provided are the same.

  The shape of the opening can be any shape such as a circle, an ellipse, or a polygon, and when a plurality of openings are provided, the arrangement is also provided so as to be evenly aligned along the outer diameter of the guide vanes. In addition, any arrangement such as a staggered arrangement may be used. Moreover, it is good also as a guide blade | wing which notched the outer peripheral part but provided the slit besides the opening part. In the case of notching, for example, the amount of water to be treated and the load on the guide vane can be adjusted by making the outer peripheral part of the guide vane into a guide vane having a notch shape such as a triangle, a quadrangle, or a trapezoid.

  Furthermore, an opening part or a slit can also be provided in the dispersion | distribution plate which is a member with which to-be-processed water collides. Also in this dispersion plate, an opening or a slit can be provided in the same manner as described above. By providing openings or slits in the dispersion plate, the amount of water to be treated and the load applied to the dispersion plate can be adjusted in the same manner as described above.

  As mentioned above, although several embodiment of this invention was described, these embodiment was posted as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10, 30, 40, 50 Sedimentation tank 11 Tank body 12 Inflow pipe 12a Inlet 13 Guide vane 14 Overflow weir 15 Outflow pipe 16 Sludge extraction pipe 17 Scratching shaft 18 Support member 19 Scraping plate 20 Drive motor 21 Shelf 31 , 41, 51 Water treatment mechanism

Claims (12)

A sedimentation tank for separating flocs contained in water to be treated,
A cylindrical or polygonal tank body;
In the tank body, an inflow pipe for supplying the treated water toward the axially lower side of the tank body,
A plurality of guide blades having openings or slits, which are provided in the inflow pipe and change the flow of the water to be treated so that the water to be treated supplied into the tank becomes a spiral flow;
A sedimentation tank comprising:   The sedimentation tank according to claim 1, wherein the guide blade is provided to be inclined with respect to a vertical plane passing through the axis of the inflow pipe.   Furthermore, it has a to-be-processed water distribution mechanism which disperse | distributes the to-be-processed water supplied from the said inflow pipe to a horizontal direction by a collision, The sedimentation tank of Claim 1 or 2 characterized by the above-mentioned.   The settling tank according to claim 3, wherein the treated water distribution mechanism has a dispersion plate.   The treated water distribution mechanism causes a cylindrical flow dividing cylinder that separates the flow of treated water supplied from the inflow pipe into two or more and a treated water separated by the flow dividing cylinder to collide with each other. The settling tank according to claim 3 or 4, wherein the settling tank comprises a plurality of dispersion plates that are dispersed in a horizontal direction.   6. A sedimentation tank according to claim 5, wherein a part of the dispersion plate is integrally attached to the outer side of the lower end of the flow dividing cylinder.   The settling tank according to claim 6, wherein the flow dividing cylinder is cylindrical, and an annular dispersion plate is integrally attached to the outside of the lower end of the flow dividing cylinder.   The settling tank according to any one of claims 5 to 7, wherein a plurality of the diversion tubes are provided.   The settling tank according to any one of claims 4 to 8, wherein the dispersion plate has an opening or a slit.   The sedimentation tank according to any one of claims 1 to 9, further comprising an annular shelf plate in a circumferential direction of a wall surface in the tank body.   11. The sedimentation tank according to claim 10, wherein the main surface of the shelf plate is inclined so that the center side is lower than the wall surface side of the tank body. It is a precipitation processing method using the settling tank of any one of Claims 1-11,
To-be-treated water supply step for supplying the to-be-treated water containing flocks from the inflow pipe into the tank so as to form a spiral flow;
A floc sedimentation step of allowing flocs contained in the water to be treated to settle while circulating the water to be treated supplied in the tank,
A precipitation step of precipitating the floc settled in the floc settling step at the bottom of the tank body;
A precipitation treatment method comprising:

Images