JPH04250802A - Vertical type deep layer precipitation tank - Google Patents

Abstract

PURPOSE:To greatly reduce the side area of the precipitation pool by making a reed screen form by hanging plural long strip materials in parallel in a specified interval and arranging them between both porous flow straighting plates at the inflow and outflow sides in a specified interval. CONSTITUTION:The water stream of a flowing velocity passed through many pores 2 in the porous flow straighting plates 3 at the inflow side passes successively through the strip materials 14 of the reed screen form bodies 11 in each section. In each section, the strip materials 14 are hanged parallel by being arranged in the left and right in the same interval and the strip bodies follow to a strong or weak flow of the horizontal stream and besides the countless fiber loops of each strip materials 14 perform cilia motions, so the equalization of the flow velocities in every each section is conducted efficiently. On the other hand, the suspended matters are imparted falling energy successively with the resistance to each strip material 14, and with the oscillations and cilia motion. The reed screen form bodies 11 are multistage in front and back, so the action is repeatedly given. Namely the similar action as the reaction acceleration in a multistage reactor is given and the precipitation of the suspended matter is accelerated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a vertical deep sedimentation tank for sedimentation treatment of sewage (including industrial wastewater, etc.), that is, the distance between the inlet where raw water flows in and the outlet where treated water flows out. It relates to a sedimentation tank that is much deeper (for example, 30 m or more) compared to the above. Note that the sedimentation tank referred to in the present invention is a concept that also includes a so-called sedimentation tank.

0002

[Prior Art] The ultra-deep sedimentation tank described in Japanese Patent Application Laid-Open No. 157310/1980 has a vertically long cylindrical tank body with
A solid-liquid separation member consisting of a plurality of inclined plates with the undiluted solution introduction side sloped downward is provided, and a porous rectifier plate is arranged on the undiluted solution introduction side of the solid-liquid separation member, and the undiluted solution is rectified by the porous rectifier plate. The sludge collides with the inclined plate and settles.

0003

[Problems to be Solved by the Invention] However, according to this, sludge adheres to the inclined plate and accumulates thereon, or the inclined plate creates an upward flow that suppresses the settling of sludge.
There are problems such as poor precipitation effect and troublesome cleaning and replacement of the solid-liquid separation member.

[0004] An object of the present invention is to provide a vertical deep sedimentation tank which has a very good sedimentation effect and is easy to maintain despite its simple structure.

[0005]

[Means for Solving the Problems] The vertical deep sedimentation tank according to the present invention has vertically elongated porous rectifying plates each having a large number of holes arranged on the inlet side and the outlet side, and also has a plurality of long string-like straightening plates. Materials or rod-shaped materials are suspended in parallel at a predetermined interval in the direction intersecting the horizontal flow to form a blind, and this is placed between the inlet side porous rectifier plate and the outlet side porous rectifier plate in the direction of the horizontal flow. A plurality of stages are arranged at predetermined intervals in the front and back. It is preferable to use a string-like material having countless fiber loops, and to hang a plurality of strings so as to be able to swing to form a curtain-like shape.

[0006]

[Operation] Because the sedimentation tank is deep and has porous rectifying plates on the inflow and outflow sides, raw water flows through the sedimentation tank from the inflow part to the outflow part at a small flow rate. The horizontal flow passing through the holes of the porous rectifying plate on the inflow side is resisted by the first plurality of strings or rods forming a curtain shape, and the horizontal flow flows through the strings or rods hanging in parallel. After passing through the space, similarly between the second string or bar, then the third,
It passes through the fourth and fourth holes in order, and finally flows out through the holes in the porous rectifier plate on the outflow side. In this case, since the horizontal flow has a small flow velocity, multiple string-like materials or rod-like materials form vertical gaps between them in parallel, so that the sedimentation action is applied in multiple stages in the direction of the horizontal flow. This will further promote the settling of suspended solids.

[0007] Therefore, due to the synergistic action as described above, the settling effect is very good, and according to the present invention, a plurality of mutually independent settling sections are arranged in parallel in multiple stages in the horizontal direction, and the treated water is sequentially transferred thereto at a small flow rate. The same effect as repeated sedimentation can be obtained, and the water area can be maximized, resulting in a reduction in the water area load within a small site area and the same effect as increasing the number of sedimentation tanks. In other words, it is possible to reduce the site area of the sedimentation pond without impairing the sedimentation effect of suspended matter. In addition, since the multiple string-like materials or rod-like materials are shaped like blinds at each stage, they can be easily replaced by simply hanging or pulling them up, and they can be forcibly swung or vibrated while maintaining the blind shape. You can easily remove adhering suspended substances by simply letting it dry.

[0008] When a plurality of string-like materials having innumerable fiber loops are hung swingably to form a blind, each string-like material itself is easy to swing freely and also floats due to frictional action. Attenuates the horizontal flow velocity of the material and promotes its precipitation.

[0009]

[Examples] Examples of the present invention will be described below. FIGS. 1 to 3 show examples in which the tank is square, and the tank body 1 is in the shape of a vertically long square tube. On the front side of this tank body 1, a vertically elongated inflow side porous current plate 3 provided with a large number of holes 2, and a vertically elongated outflow side multihole current plate 5 provided with the same large number of holes 4 on the rear side are arranged vertically. An inflow portion 7 is formed between the front wall 6 of the tank body 1 and the inflow side porous current plate 2, and an outflow portion 9 is formed between the rear wall 8 and the outflow side porous current plate 5. In the illustrated example, the front portion of the bottom portion 10 of the tank body 1 is inclined downward from the inflow side to the outflow side, but it may be horizontal.

Inflow side porous current plate 2 and outflow side porous current plate 5
Between the left and right walls 12 and 13 of the tank body 1, a plurality of screen-like bodies 11 are suspended in multiple stages in the front and rear at predetermined intervals in the front and rear. Each screen-like body 11 has a large number of long string-like members 14 suspended from horizontal support rods 15 at a predetermined interval so as to be swingable, and can be attached to and detached from the tank body 1 individually. It has become. The distance between the blinds 11 is, for example, about 10 cm,
The distance between the strings 13 in each screen 11 is, for example, about 3c.
It is m. As the string-like material 14, it is preferable to use a known string-like filter material that has countless fiber loops and is twisted spirally to provide elasticity.

In the above configuration, while raw water (sewage) flows into the inflow section 7, treated water flows out from the outflow section 9 (
For example, when the flow is overflowed), the raw water that has flowed into the inflow section 7 is rectified by passing through the many holes 2 of the inflow side porous current plate 3, and flows from the inflow section 7 to the outflow section 9 side. In this case, because the tank body 1 is deep and the porous rectifying plates 3 and 5 are arranged on the inflow side and the outflow side, the water flows at a small flow rate.

[0012] The horizontal flow at a slight velocity passing through the large number of holes 2 of the inflow side porous rectifying plate 3 passes through the string-like material 14 of the screen-like body 11 of each section in the first, second, third and so on. pass between. In each section, the string-like materials 14 are lined up left and right at equal intervals and hang down in parallel, and the string-like materials 14 oscillate according to the strength of the horizontal flow, and each string-like material 14 has countless fibers. Because the loops make ciliary motion, the flow velocity is efficiently averaged in each section, and the averaging progresses further from the front section to the rear section. Since the string-like material 14 has elasticity, it can swing even if its upper and lower ends are fixed.

At the same time that the flow velocity of the horizontal flow is averaged in this way, the suspended solids are sequentially given downward energy by the resistance and oscillation of each string material 14 and the ciliary movement of the fiber loops. In addition, since the screen-like bodies 11 are arranged in multiple stages in the front and back, they are repeatedly exposed to this effect, which is similar to the reaction promotion in a multi-vessel reaction tank, and the sedimentation of suspended substances is promoted.

FIGS. 4 and 5 show an example of a circular tank body 1.
has a vertically elongated cylindrical shape with a conical bottom, and a pipe-shaped inflow section 7 is provided in the center thereof, and around this, the inflow side porous current plate 3, the plurality of blinds 11, the outflow side porous current plate 5, and the outflow side are connected. The parts 9 are arranged concentrically, and the operation is the same as that described above.

In order to confirm the action and effect of the present invention, the present inventors conducted the following experiment using a transparent model sedimentation tank. Figures 6 and 7 show an example of the experiment, in which the depth of the model settling tank 16 is 120 cm, the front and back length is 60 cm, the left and right width is 15 cm, the height of the porous rectifier plates 17 and 18 on the inflow side and outflow side is 120 cm, and the left and right sides are 120 cm. The width is 15 cm, the thickness is 3 mm,
Each of these porous current plates 17 and 18 was provided with holes 19 having a diameter of 8 mm in 46 stages vertically and in 7 rows horizontally. The front and rear widths of the inflow section 20 and the outflow section 21 are both 5 cm. Between the porous rectifying plates 17 and 18, a screen-like body 22 is placed 10 cm back and forth.
They were placed in four locations at intervals of . As each screen-like body 22, five string-like filter media 23 having the above-mentioned structure are suspended from support rods at intervals of 3 cm, and the lower ends of each string-like filter media 23 are attached to the bottom of the model sedimentation tank 16. Fixed. Tap water was previously filled in the model sedimentation tank 16 up to the height (115 cm) at which it flows out from the outflow pipe 24 of the outflow section 21, and an injection pipe with a diameter of 2 cm was provided with 19 steps of holes 25 each having a diameter of 4 mm at intervals of 5 cm above and below. 26 into the inflow part 20, and the raw water (S
S concentration 611 mg/liter) was injected at a flow rate of 2.1 liters per minute.

[0016] Figures 8 to 15 are diagrammatic representations of the density distribution of activated sludge in the model settling tank 16 observed in this experiment. , Figure 10 is after 10 minutes, Figure 11 is after 20 minutes, Figure 12 is after 30 minutes, Figure 13 is after 40 minutes, Figure 14 is after 50 minutes, Figure 15 is after 60 minutes.
Each shows the situation after a minute. In this experiment, the sedimentation of activated sludge was carried out in stages separated by screen-shaped bodies 22, and a swirling flow was observed in each section as if it were occurring in one sedimentation tank, and the above-mentioned effects occurred. This was confirmed.

[0017] In the above embodiment, a string-like filter material having countless fiber loops formed therein and twisted spirally to provide elasticity was used as the string-like material, but other forms of string-like material may be used. However, it is also possible to use not only a string-like material but also a bar-like material.

[0018]

Effects of the Invention According to the present invention, a plurality of long string-like materials or rod-like materials are hung in parallel at predetermined intervals to form a blind, and these are connected to the inflow side porous current plate and the outflow side porous current plate. By simply arranging multiple stages at a predetermined distance from front to back in the direction of water flow, a plurality of mutually independent settling sections are arranged in parallel in multiple stages in the horizontal direction, and treated water is sequentially transferred thereto at a small flow rate. Since the same effect as repeated precipitation can be obtained, it can be done effectively and economically by increasing the depth within a small plane area. In other words, the site area can be significantly reduced compared to conventional sedimentation ponds, and the entire treatment facility can be housed within a narrow site.

[0019] Furthermore, since the plurality of string-like materials or rod-like materials are shaped like blinds at each stage, they can be easily replaced by simply hanging and pulling them up. Adhering floating substances can be easily removed by simply moving or vibrating, making maintenance easy.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view of an example of a rectangular vertical deep sedimentation tank according to the present invention.

FIG. 2 is a schematic plan view of the same as above.

FIG. 3 is a schematic cross-sectional view of the same as above.

FIG. 4 is a partially cutaway perspective view of an example of a circular shape.

FIG. 5 is a plan view of the same as above.

FIG. 6 is a perspective view of an experimental example using a model settling tank.

FIG. 7 is a plan view of the same as above.

FIG. 8 is a density distribution diagram 2 minutes after the injection of activated sludge in an experimental example.

FIG. 9 is a shading distribution map after 8 minutes.

FIG. 10 is a density distribution diagram after 10 minutes.

FIG. 11 is a density distribution diagram after 20 minutes.

FIG. 12 is a density distribution diagram after 30 minutes.

FIG. 13 is a density distribution diagram after 40 minutes.

FIG. 14 is a density distribution diagram after 50 minutes.

FIG. 15 is a density distribution diagram after 60 minutes.

[Explanation of symbols]

1 Tank body 2 Hole 3　　　　Inflow side porous rectifier plate 4 Hole 5 Outflow side porous rectifier plate 7 Inflow section 9 Outflow part 11. Curtain-like body 14 String material

Claims (2)

[Claims] Claim 1: A vertically elongated porous rectifier with a large number of holes in a vertical deep sedimentation tank that is much deeper in depth than the distance between the inlet where raw water flows in and the outlet where treated water flows out. Plates are respectively arranged on the inlet side and the outlet side, and a plurality of long string-like materials or rod-like materials are hung in parallel at a predetermined interval in a direction intersecting the horizontal flow to form a blind shape, A vertical deep sedimentation tank characterized in that a plurality of layers are arranged at a predetermined interval back and forth in the direction of horizontal flow between an inflow side porous current plate and an outflow side porous current plate. 2. The vertical deep sedimentation tank according to claim 1, characterized in that a cord-like material having countless fiber loops is used, and a plurality of cord-like materials are swingably suspended to form a screen-like screen.