JP4760398B2 - Pressure levitation device - Google Patents

Description

  The present invention relates to an apparatus for subjecting SS to water that contains suspended solids (SS) under pressure levitation separation. In particular, the load on the water area of the levitation tank can be increased with simple equipment. The present invention relates to a pressurized levitation device that can be downsized and improve processing efficiency.

  As a kind of treatment method for water containing SS, raw water is mixed with pressurized water and supplied to the levitation tank. In the tank, SS in the raw water is adsorbed by micro air and floated on the surface of the water. There is a pressure levitation treatment method that rakes out and discharges. There are square and round levitation tanks used in this pressurized levitation treatment method, but in many cases, round cavities are adopted from the standpoint of reducing the installation area and improving the sludge drainage efficiency. ing.

In a round pressure levitation device, mixed water of raw water and pressurized water (hereinafter sometimes simply referred to as “mixed water”) is supplied from the bottom of the levitation tank to the top of the tank through a feed well provided inside the tank. (For example, JP-A-2000-176437).
JP 2000-176437 A

  In order to stably and reliably obtain treated water with good water quality by the pressurized levitation treatment method, it is an important condition that the micro air generated from the pressurized water is efficiently adsorbed to the SS in the raw water.

According to the present invention, the fine bubbles are efficiently attached to the flocs, and the raw water flowing out from the feed well is prevented from flowing out of the tank in a short-circuit manner, thereby enabling the flotation separation process to be performed efficiently. An object is to provide an apparatus .

The pressurized levitation device of the first invention comprises a levitation tank and a feed well provided in the levitation tank, the upper part of which is open, and raw water containing fine bubbles is supplied to the lower part of the feed well. In the pressurized levitation apparatus that rises in the feed well and is introduced into the levitation tank from the upper opening, the pressurized levitation apparatus is provided with an annular baffle surrounding the upper portion of the feed well, the baffle being A column in which a plurality of circular baffles of equal diameter with different vertical heights are provided coaxially, and a plurality of columns are provided coaxially with different distances from the feed well. Of the columns, at least one annular baffle constituting the column on the side farther from the feed well is approximately the middle of two adjacent annular baffles constituting the column on the side closer to the feed well. And it is characterized in that it is disposed at a height.

The pressurized levitation device of the second invention comprises a levitation tank and a feed well provided in the levitation tank, the upper part being open, and raw water containing fine bubbles is supplied to the lower part of the feed well. In the pressurized levitation apparatus that rises in the feed well and is introduced into the levitation tank from the upper opening, the pressurized levitation apparatus is provided with an annular baffle surrounding the upper portion of the feed well, the baffle being A column in which a plurality of circular baffles of equal diameter with different vertical heights are provided coaxially, and a plurality of columns are provided coaxially with different distances from the feed well. Among the columns, at least one annular baffle constituting a column on the side far from the feed well is composed of two adjacent annular baffles constituting a column on the side closer to the feed well. Than the height of the lower annular baffle, it is characterized in that it is arranged in 0-1 / 3 times the distance lower position of the two annular baffle spacing in contact 該隣.

A pressurized levitation device according to a third aspect of the present invention comprises a levitation tank and a feed well provided in the levitation tank, the upper part of which is open, and raw water containing fine bubbles is supplied to the lower part of the feed well. In the pressurized levitation apparatus that rises in the feed well and is introduced into the levitation tank from the upper opening, the pressurized levitation apparatus is provided with an annular baffle surrounding the upper portion of the feed well, the feed well Is disposed in the center of the tank body and is provided with a rotary scum skimmer coaxially with the feed well, and the annular baffle is non-circular, supported by the scum skimmer, and integrated with the scum skimmer. It is characterized by being rotatable .

In the pressurized levitation apparatus of the present invention, an annular baffle is provided so as to surround the upper part of the feed well. When the raw water flowing out from the feed well hits this baffle, the association frequency between the fine bubbles and the floc increases, and the amount of fine bubbles adhering to the floc increases. Further, by providing this baffle, the flow rate in the radial direction of the raw water flowing out from the feed well is reduced and the flow becomes uniform. By synergizing such effects, according to the present invention, the flotation separation process is efficiently performed.

In addition, when a baffle is comprised like 1st invention , the raw | natural water which flowed out from the feed well is fully disperse | distributed by a baffle.

When the baffle is configured as in the second aspect of the invention, the raw water flow that flows out of the feed well and flows radially and obliquely downward is sufficiently dispersed.

  The baffle is preferably annular, but may be non-annular (eg, polygonal). In the case of a non-annular baffle, the distance from the feedwell to each part of the baffle will have a distribution. If the non-annular baffle is rotated coaxially with the feed well, the distance from the feed well to each part of the baffle is equalized over time, so that the effect is almost equivalent to that of the annular baffle. be able to.

  In the pressurized levitation device in which the raw water inflow pipe flows in the tangential direction with respect to the feed well, a drift occurs in the flow in the levitation tank due to the influence of the flow in the feed well as shown in FIG. The annular baffle of the present invention has an effect of making the flow of water from the feed well to the levitation tank uniform, and can weaken the drift. Therefore, in such a pressure levitation device, the effect is remarkable. .

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 (a) is a longitudinal sectional view of a pressure levitation apparatus according to an embodiment, and FIG. 1 (b) is a plan view of the pressure levitation apparatus (however, scum rake is not shown). FIG. 2 is a sectional view for explaining the arrangement of baffles.

  In this pressurized levitation device, the inner tank 2 is provided along the inner periphery of the circular tank body 1 of the floating tank, and the treated water can rise between the tank body 1 and the inner tank 2. A feed well 10 is erected at the center of the tank body 1, a raw water inflow pipe 3 is connected to the feed well 10 in a tangential direction, and a pressurized water inflow pipe 4 is connected to the raw water inflow pipe 3.

  The raw water and the pressurized water flow into the levitation tank through the feed well 10 from the inflow pipes 3 and 4, and solid-liquid separation is performed. The treated water goes around the lower end of the inner tank 2, rises between the inner tank 2 and the tank body 1, and is discharged from the treated water trough 5. On the other hand, the floating scum is scraped by a scum rake (skimmer) 6 and dropped into a scum box 8, and is discharged from a discharge port (not shown). Reference numeral 7 denotes a motor for driving the scum rake 6.

  A plurality of annular baffles 20 are provided coaxially so as to surround the upper portion of the feed well 10.

  The baffle 20 is supported by the feed well 10 or the scum rake 6 via a support member.

In this embodiment, all of the baffles 20 have an annular shape, and are adjacent to the outer peripheral side of the first row C ₁ baffles 20 arranged in two upper and lower stages on the innermost peripheral side, that is, on the feed well 10 side. The second row C ₂ baffles 20 are arranged in two upper and lower stages, and the third row C ₃ baffles 20 are arranged in two upper and lower stages on the outermost periphery farthest from the feed well 10.

In this embodiment, the baffle 20 has a staggered arrangement. That is, the lower one of the baffles 20 in the second row C ₂ is positioned at a substantially middle height of the baffles 20, 20 in the first row C ₁ , and the upper one is higher than the baffles 20 in the first row C _2. positioned. Baffle 20 of the third column _{C 3} is located at the same height and the baffle 20 of the first column _{C 1.}

In any of C ₁ , C ₂ , and C ₃ , the vertical intervals between the baffles 20 are substantially the same.

The baffle 20 is preferably made of a pipe or a solid bar. The thickness (diameter) of the baffle 20 is preferably about 10 to 100 mm, particularly about 20 to 60 mm. The distance between the columns C ₁ , C ₂ and C ₃ is preferably about 20 to 300 mm, particularly about 50 to 200 mm. The vertical distance of the baffle 20 is preferably about 20 to 300 mm, particularly about 50 to 200 mm.

  In the case of the staggered arrangement of FIG. 2, the frequency of contact between the water flowing in the radial direction from the feed well 10 and the baffle 20 is high, and fine bubbles adhere efficiently to the floc.

  Therefore, according to this pressurized levitation device, the mixed water that has risen in the feed well 10 and has flowed into the levitation tank from the upper end thereof is dispersed by the baffle 20, and fine bubbles are sufficiently adhered to the flocs. Separated to float. Further, the mixed water is prevented from flowing out of the tank in a short circuit, and the floating separation process can be sufficiently performed.

  The number of the baffles 20 in this embodiment is an example, and is not limited to this. The number of rows of baffles 20 is preferably about 2 to 10, particularly about 3 to 5. The number of baffles 20 in one column in the vertical direction is preferably about 2 to 10. The number of baffles 20 in the innermost circumferential row closest to the feed well 10 is preferably about 2 to 4, and is preferably about 0 to 8 more than that in the second and subsequent rows.

[Another arrangement example of the baffle 20]
Since water flows out from the feed well 10, when the water depth at the upper end of the feed well is slightly deep, the water flowing out from the feed well may flow obliquely upward.

In such a case, as shown in FIG. 3, it may be arranged a baffle 20 of the outermost rows C ₃ to higher than the baffle 20 on the inner circumferential side of the columns C _1, C ₂ than . In this case, the lower side of the baffle 20 in the third column C ₃ is located in the middle of the top and bottom of the second column of baffles. Further, the upper baffle 20 of the third column C ₃ is located above the baffle 20 of the upper second column.

It is also possible to place the second column C ₂ of the baffle 20 to the upper than the first column C ₁ of the baffle as well as the baffle 20 of the third column C _3.

[Another arrangement example of the baffle 20]
Since water tends to sink as it approaches the outer periphery of the tank body, the outermost peripheral row, for example, the third row of baffles 20 is more than the height of the second row of baffles 20 on the inner peripheral side. You may arrange | position in the position low by the distance of 0-1 / 3 time (for example, 1/4 time of H) of the space | interval H of each baffle of 2 rows.

[Effect of toroidal baffle]
In the above embodiment, the baffle 20 has an annular shape, and the distance between the baffle 20 and the feed well 10 is constant in the circumferential direction of the baffle 20. That is, it is isotropic as viewed from the feedwell 10. Accordingly, water flowing out from the feed well 10 in any direction is treated substantially evenly.

[Non-ring baffle]
In the present invention, a polygonal, for example, hexagonal or octagonal baffle may be installed instead of the annular baffle. This polygonal baffle can be easily manufactured by simply joining straight bars.

  In this polygonal baffle, the distance between each part of the baffle and the feed well 10 is distributed in the circumferential direction of the feed well 10. That is, the polygonal baffle is not isotropic when viewed from the feedwell 10. For example, the distance between the vertex of the polygon and the feed well 10 is the maximum, and the distance between the midpoint of the polygon side and the feed well 10 is the minimum.

  In the case of such an anisotropic baffle, the baffle is suspended from the scum rake 6 and the baffle is integrally fed with the scum rake 6 so that the water discharged from the feed well can be evenly treated. It is preferable to rotate around 10.

  FIG. 4 is a plan view showing an example of a pressure levitation device in which hexagonal baffles 26 are arranged in three rows (scum rake is not shown).

[Further different aspects]
The above embodiment is an example of the present invention, and the present invention may take forms other than those shown in the drawings. For example, the cross-sectional shape of the baffle 20 may be a square or an ellipse. Moreover, you may further arrange | position the baffle along the circumferential surface of a levitation tank. The levitation tank may not have an inner tank.

It is sectional drawing and the top view of the pressurization levitation apparatus concerning an embodiment. It is a baffle arrangement | positioning in embodiment. It is a baffle arrangement | positioning in another embodiment. It is a baffle arrangement | positioning figure in different embodiment. It is a top view explaining the flow of the water in a levitation tank.

DESCRIPTION OF SYMBOLS 1 Tank body 2 Inner tank 3 Raw water inflow pipe 4 Pressurized water inflow pipe 5 Treated water trough 6 Scum rake (skimmer)
8 Scum box 10 Feed well 20, 26 Baffle

Claims (4)

A floating tank,
A feed well provided in the levitation tank with an open top;
With
In the pressurized levitation device, the raw water containing fine bubbles is supplied to the lower part of the feed well, rises in the feed well, and is introduced into the levitation tank from the upper opening.
A pressure levitation device provided with an annular baffle surrounding an upper portion of the feed well,
The baffle is a column in which a plurality of circular baffles having the same diameter and different vertical heights are provided coaxially, and a plurality of columns are provided adjacent to each other at different distances from the feed well. Of two columns, at least one annular baffle constituting a column on the side far from the feed well is adjacent to two annular baffles constituting a column on the side closer to the feed well It is arrange | positioned in the substantially intermediate | middle height of the pressurization levitating apparatus characterized by the above-mentioned. A floating tank,
A feed well provided in the levitation tank with an open top;
With
In the pressurized levitation device, the raw water containing fine bubbles is supplied to the lower part of the feed well, rises in the feed well, and is introduced into the levitation tank from the upper opening.
A pressure levitation device provided with an annular baffle surrounding an upper portion of the feed well,
The baffle is a column in which a plurality of circular baffles having the same diameter and different vertical heights are provided coaxially, and a plurality of columns are provided adjacent to each other at different distances from the feed well. Of two columns, at least one annular baffle constituting a column on the side far from the feed well is adjacent to two annular baffles constituting a column on the side closer to the feed well The pressure levitation apparatus is disposed at a position lower by 0 to 1/3 times the interval between the two adjacent annular baffles than the height of the lower annular baffle. A floating tank,
A feed well provided in the levitation tank with an open top;
With
In the pressurized levitation device, the raw water containing fine bubbles is supplied to the lower part of the feed well, rises in the feed well, and is introduced into the levitation tank from the upper opening.
A pressure levitation device provided with an annular baffle surrounding an upper portion of the feed well,
The feed well is disposed in the center of the tank body, and a rotary scum skimmer is provided coaxially with the feed well,
The annular floating baffle is a non-circular shape, is supported by the scum skimmer, and is rotatable integrally with the scum skimmer. In any one of claims 1 to 3, the raw water inlet pipe for flowing raw water containing fine bubbles in the feed well, the dissolved air flotation, characterized in that it is connected in a substantially tangential direction relative to the feed-well device .

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