JPS63209709A - Method and apparatus for sedimentation of suspended particles - Google Patents

Abstract

PURPOSE:To efficiently carry out sedimentation of suspended particles by verti cally and horizontally disposing fins parallelly inclined with a specified angle to the flowing direction and by forming downward laminar parallel flow of suspension and pocket circulating flows between columnar fins. CONSTITUTION:Many fins inclined at a 30-90 deg. angle to the direction of down ward flow keeping parallel interval are vertically and horizontally disposed in a sedimentation tank, and suspension liquid flows W form laminar parallel flows W' between fin columns and generate circulating flows 18 in pocket parts 14 formed between columnar fins, and trailing vortex sequences 16 are generated by the upstream side edges of fin working as laminar flow break- away points. As a result, the floc particles in the laminar parallel flow are rolled up into the trailing vortex sequence and flow into the circulating flow, and are coagulated by the collisions between particles or between particles and the surface of fin plate, and flow again into the parallel flow from the lower opening part of the pocket to catch and grow floc particles there. Conse quently, the sedimentation is efficiently carried out without sticking and piling-up of flocs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for sedimentation and separation of suspended particles in a sedimentation tank.

[Conventional technology]

Conventionally, this type of sedimentation separation method and S installation are known as shown in FIG. The fin ζ separates the suspension channel from the sedimentary floc passage.
The configuration is as follows.

[Problem that the invention seeks to solve]

In the conventional device, floc particles in the suspended flow flow into the circulating flow ζ in the fin pocket 26, aggregate due to the collision of each other and the particles with the fin plate surface, and pass through the narrow floc slide path 28 to become flocs. Since the flocs formed in the fin pockets 26 do not flow down into the suspension flow, they have no chance of coming into contact with floc particles in the suspension flow (and are deposited on the fin bends, causing the flocs to There is a problem that the sliding path 2B and the flock passage section 30 are blocked.

Therefore, although a cleaning device is installed, cleaning work during operation is insufficient, and there is the hassle of having to empty the sedimentation tank to remove the sludge.

[Purpose of the invention]

An object of the present invention is to provide a sedimentation separation method and apparatus for efficiently performing the tangential sedimentation separation of settled flocs and suspended particles.

[Summary of the invention]

In order to achieve the above object, the sedimentation separation method of the present invention is such that floc particles in the suspended flow flowing in the main channel 10 between the left and right fins as a laminar parallel flow W/ move the edge of the upstream fin to a boundary layer separation point. The particles are caught in the wake vortex line 16, and as the flow of this wake vortex line 16 flows, they flow into the circulating flow 18 in the pocket ray between the vertical fins, and due to the collision action of each other and the particles and the plate surface of the fins 12. The grown flocs are aggregated and granulated into flocs, and the flocs that have grown are successively lowered by gravity from the bottom of the opening of the pocket portion 14, and a laminar parallel flow W/
The method is characterized in that the floc particles enter the flowing suspended flow, and the floc particles floating in this suspended flow are captured, further enlarged, and sequentially separated by Iζ sedimentation. The sedimentation separator of the present invention is arranged so as to maintain parallel spacing in the sediment plane and in the vertical plane, and forms a main channel 10 between the left and right fins in which the suspension flow W flows as a parallel flow W/. , a pocket portion 14 whose left and right surfaces are open to the main flow path 10 is formed between the column fins, and when the suspension flow W flows through the main flow path 10, a wake vortex row 16 is formed with the upstream fin edge as a boundary layer separation point. This feature is characterized in that a circulating flow 18 is generated inside the pocket.

[Embodiments of the invention]

Hereinafter, a sedimentation separation apparatus directly used for carrying out the sedimentation separation method of the present invention will be explained with reference to the drawings of FIGS. 1 and 2.

The #I device for sedimentation of suspended particles has a lower angle θ in the sedimentation tank 20.
(In the case of this embodiment, θ-=600) A large number of fins 12 facing each other are arranged as shown in the jcTh1 diagram so as to maintain parallel spacing in the horizontal plane and the vertical plane, and are fixed with the fin support plate 22. By doing so, a main flow path 10 is formed in which the suspension flow W flows as a laminar parallel flow W/ between the left and right fins, and the left and right surfaces between the vertical fins form the main flow path l.
A pocket portion 13 with an O-opening is formed.

The sedimentation separator configured in this way has the advantage that when the suspended flow W flows through the main channel 10 between the left and right fins as a laminar parallel flow W/, the boundary between the flow in the main channel 10 and the stationary fluid in the fin pocket 14 When the wake vortex street 16 with the boundary layer separation point at the upstream fin edge is generated, suspended particles flowing along the laminar parallel flow W/ approach the wake vortex street 16. Get caught up in it. At this time, since a circulating flow 18 rotating at a low speed is formed in the pocket portion 14 of the fin 12, the floc particles caught in the wake vortex line 16 are removed from the wake vortex line 16.
6 flows into the pocket circulating flow 18 and circulates and swirls in the pocket part 14. As a result of this, collisions occur between the particles and between the particles and the fin plate surface, and by repeating this collision action, the fin plate surface is swept away. However, it aggregates and becomes granulated into flocs. Then, the flocs that have grown inside the fin pocket section 14 gradually descend from the bottom of the opening of the pocket section 14 due to gravity, and then move to the side! ! The parallel flow W/ is swept into the flowing suspension flow, and at this time, the floc particles floating in the turbid flow and the floc particles that settle are captured, and the floc particles become further enlarged and are sequentially sedimented and separated.

That is, the flocs successively increase the frequency of contact and collision with the suspended particles to promote growth, and the floc structure is gradually changed to a larger floc structure, which reaches the bottom of the sedimentation tank in a short time, allowing efficient sedimentation. They will be separated.

In this case, the flocs release the water and fine air contained in the flocs by repeating swirling and contact collisions, thereby weakening the buoyancy of the particles, and irregular particle shapes also have a small surface area. Modified into circular flocs with good sedimentation efficiency.

Circulation of a small swirling flow is important for the formation, growth or modification of the flocs. Since the sedimentation separator according to the present invention generates a small swirling circulation flow 18, it is possible to effectively create coagulated flocs with good sedimentation separation.

Although the direction of the suspension flow illustrated in FIGS. 1, 2, and 3 is a downward flow, a similar sedimentation separation can be obtained with an upward flow. In addition, by providing partitions in the sedimentation tank and installing upflow devices and downflow devices alternately, in the upflow device, the suspended flow and settling flocs flow in opposite directions, so that the settling flocs are Since the descent is slow due to resistance, the frequency of contact and collision with floc particles in the suspended flow increases.In a downward flow device, the suspended flow and the settling floc flow in the same direction, so the floc reaches the bottom of the settling tank quickly, making it more effective. When the target I is sedimented and separated, it becomes J(.

Although the illustrated cross section of the fin 12 is a flat plate, the cross section may be shaped into an arc, a lens, a flattened rhombus, or the like in order to provide rigidity to the member. Further, the material of the fins 12 may be any non-corrosive material such as synthetic resin and has good surface lubricity.

FIG. 3 shows an embodiment in which the fins 12 are arranged laterally in a figure eight shape to form the pocket 14 in a trapezoidal shape. Although the edges of the left and right fins 12 facing each other across the main flow path 10 are arranged on the same horizontal plane in the t42 and taa diagrams, they may be vertically shifted.

〔Effect of the invention〕

Since the method for sedimentation and separation of suspended particles of the present invention is as described above, by increasing the frequency of contact and collision between sedimented flocs and suspended particles, promoting the growth of flocs, and modifying the structure of flocs, Suspended particles can be efficiently sedimented and separated.

In addition, the fin member of the sedimentation separation device for suspended particles according to this invention number ζ is not bent, and the floc sedimentation passage is wide.
In addition, since the edge of the fin serves as a separation point of the boundary layer of the suspended flow, the problems of floc adhesion, accumulation, and blockage can be easily solved.

Therefore, a cleaning device is not required.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a sedimentation separation device showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of a sedimentation separation method using the same device-ζ, and Fig. 3 shows a configuration in which the arrangement of fins is changed. FIG. 4 is an explanatory diagram of a conventional bag device corresponding to FIG. 2 of the present invention. W... Suspension flow W /... Laminar parallel flow x... Turbulence in the flow direction of suspension flow 10... Main channel 12... Fin 14... Pocket 16... Wake vortex row 18...Circulating flow

Claims (2)

[Claims] (1) The floc particles in the suspended flow flowing in the main channel between the left and right fins as a laminar parallel flow are caught in the wake vortex street with the boundary layer separation point at the upstream fin edge, and this wake vortex street As the flow flows, the particles flow into the circulation flow in the pocket between the vertical fins, and are aggregated and granulated into flocs by the collision of each other and the particles with the fin plate surface, and the grown flocs are released from the bottom of the pocket opening by gravity. The suspension is characterized in that it enters a suspension stream that descends sequentially and flows next to it as a laminar parallel flow, traps floc particles suspended in this suspension stream, enlarges them, and sequentially sediments and separates them. Sedimentation separation method for turbid particles. (2) 30° relative to the flow direction of the vertical suspension flow in the settling tank
A large number of fins facing each other at an angle of ~90° are arranged so as to maintain parallel spacing in a horizontal plane and a vertical plane to form a main channel between the left and right fins through which a suspended flow flows as a laminar parallel flow, A pocket portion with left and right surfaces open to the main channel is formed between the vertical fins, and when the suspension flow flows through the main channel, a trailing vortex train with the upstream fin edge as a boundary layer separation point and circulation inside the pocket are formed. A sedimentation separation device for suspended particles characterized by generating a flow.