JPH0299106A - Solid-liquid separator - Google Patents

Abstract

PURPOSE:To prevent the lowering of solid-liquid separation efficiencies by providing an inlet port for guiding a liquid to be treated into a separation section and a discharge port for guiding a treated liquid having been treated to the outside of a separation tank. CONSTITUTION:A liquid to be treated flowing into a separation tank 1 from an inlet port 5 is caused to whirl, being surrounded by a guide plate 50 and a side wall 2 to be guided thereby, and released from the guide plate 50 where the liquid is spaced the largest distance from a discharge port 9. Consequently, the liquid to be treated whirls sufficiently, without taking a minimum path toward the port 9 even if under small centrifugal forces, while floatable solids 21 rises to the free surface 8 of the liquid to be treated and solids 20 having a property to be precipitated are precipitated toward a bottom wall 3, wherein high separation efficiencies are maintained.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a solid-liquid separator that performs solid-liquid separation by concentrating a liquid containing solids, such as sewage in a combined sewer system. .

[Conventional technology]

In a combined sewer system, a sewer system is provided that is connected directly to a pump station or a sewage treatment plant, and sewage is led to the sewer system for sewage treatment.

When the weather is sunny, only sewage is led to the sewer system, and the pollutants are removed from the sewage at a treatment plant to become clean water, which is then discharged into the river.

On the other hand, in the case of rainy weather, especially when heavy rain suddenly occurs, a large amount of rainwater flows into the sewers, far exceeding the sewage treatment capacity of the sewage treatment plant, resulting in a large amount of pollution. There was a problem that water flowed into the river and polluted the water quality of the river.

In order to solve the above-mentioned problems, the present applicant has developed a solid-liquid separator as shown in Japanese Patent Application No. 58-50367 (Japanese Unexamined Patent Publication No. 59-177105).

FIG. 3 is a diagram showing an example of such a conventional solid-liquid separation device, where (a) is a plan view, and (b) is a plan view of the same.
FIG.

As shown by arrow A in the figure, the liquid to be treated containing solids flows from the inflow port 5 into the separation tank 1 from the tangential direction through the inflow channel 4, and then swirls along the side wall 2. Head towards outlet 9. In the meantime, the settleable solids 20 settle to the bottom wall, and the floatable solids 21 float to the free surface 8. The treated liquid from which solids have been removed in this way flows out from the outlet 9. On the other hand, the sedimentary solids 20 are contained in the bottom wall 3 of the separation tank 1.
The floating solids 21 flow out from the overflow pipe 7.

[Problem to be solved by the invention]

However, in the conventional solid-liquid separator as described above, if the device is enlarged while the inflow velocity u0 of the liquid to be treated flowing into the separation tank 1 is kept constant, the separation tank 1 becomes larger. As the radius R increases, the centrifugal force u6''/R decreases. Therefore, the liquid to be treated that flows in the tangential direction of the separation tank 1 does not follow the side wall of the separation tank 1, and instead flows as shown in Fig. 3(a). As shown by arrow B, the liquid goes to the outlet 9 via the shortest path with the least flow loss.As a result, the distance the liquid to be treated travels from the inlet 5 to the outlet 9 is reduced, and the solid-liquid There was a problem that the separation rate decreased.

Furthermore, the above Japanese Patent Application No. 58-50367 describes an example in which a guide plate is provided to direct the liquid to be treated flowing in from the inlet 5 away from the side wall 2 of the separation tank 1. However, with this configuration, the liquid to be treated becomes more likely to separate from the side wall 2, so that the above-mentioned problem becomes more serious.

This invention was made in view of the above points, and even if the solid-liquid separator becomes large and the centrifugal force of the liquid to be processed increases
It is an object of the present invention to provide a solid-liquid separation device that allows the flow of the liquid to be treated to follow the side wall of a separation tank 1 even when the liquid is low.

[Failure to solve the problem]

In order to solve the above problems, the present invention provides a solid-liquid separator having a separation tank that performs solid-liquid separation while swirling the contained liquid to be treated, which is introduced into a cylindrical container having a bottom wall. , comprising an inlet for guiding the liquid to be treated into the separation tank, and an outlet for guiding the treated liquid after separation treatment to the outside of the separation tank, and the inlet and the outlet are part of the side wall of the separation tank. or a part of the bottom wall,
The outlet is disposed at a position 180 degrees or more away from the inlet along the swirling flow direction of the liquid to be treated, and is a guide for guiding the flow of the liquid to be treated that has flowed in from the inlet along the side wall of the separation tank. The plate was erected, and the downstream end of the guide plate was configured to be separated from the inlet by 90 degrees or more along the swirling flow direction of the liquid to be treated.

[Effect]

Because the solid-liquid separator is configured as described above, even if the device becomes larger and the centrifugal force of the liquid to be treated swirling in the separation tank becomes smaller, the liquid to be treated that flows in the tangential direction of the separation tank will flow through the guide plate. The liquid is guided and rotates along the side wall of the separation tank, so that the moving distance of the liquid to be treated from the inlet to the outlet does not decrease, and a sufficient solid-liquid separation rate is maintained.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a solid-liquid separator according to an embodiment of the present invention, in which (a) is a plan view and (b) is a plan view.
) is a cross-sectional side view taken along line II of FIG.

As shown in the figure, this solid-liquid separator has an inlet 5 on a side wall 2 of a separation tank 1 for introducing the liquid to be treated into the separation tank, and an outlet port for guiding the treated liquid after separation treatment to the outside of the separation tank. 9 is attached, and an overflow pipe 30 is attached to the center of the separation tank 1, and a recess 4 provided in the center of the bottom wall 3 of the separation tank 1 is attached.
A sand pump 41 is disposed at the separation tank 1, and a guide plate 50 for guiding the flow of the liquid to be treated flowing in from the inlet 5 along the side wall 2 of the separation tank 1 is provided upright.

Each component of the solid-liquid separator will be described in detail below.

The separation tank 1 has a side wall 2 and a bottom wall 3, which are formed into a substantially circular shape (or other desired shape such as an ellipse).

The inlet 5 of the inlet passage 4 is connected to the separation tank 1 so that the liquid to be treated is introduced tangentially to the side wall 2 and the liquid to be treated is given a swirling motion along the side wall 2 in the separation tank 1. side wall 2
Attach to. The inlet 5 may be partially located on the bottom wall 3, or may be located only on the bottom wall 3.

The bottom wall 3 is sloped from the outer periphery toward the center in a conical shape. Note that the bottom wall 3 may be formed in a horizontal plane.

A recess 40 is formed near the center of the bottom wall 3 of the separation tank 1 in which the sedimentable solids settle. A sand pump 41 is disposed within the recess 40 to appropriately discharge the settling solids 20 from the discharge pipe 42.

In addition, the outlet 9 is connected to the inlet 5 in order to perform sufficient solid-liquid separation.
18 along the flow direction of the liquid to be treated on the inner periphery of the side wall 2.
It is preferable to provide it at a position at an angle of 0 degrees or more. Here, the outlet 9 may be located partially on the bottom wall 3 or only on the bottom wall 3. The downstream side of the outlet 9 is connected to a river or the like.

The overflow pipe 30 is provided in the center of the separation tank 1,
Its upper end is opened upward at a predetermined position in the separation tank 1, and its lower end passes through the recess 40 and is inserted into the separation tank 1.
guided externally.

The guide plate 50 is erected inside the separation tank 1.

The guide plate 50 extends parallel to the side wall 2 of the separation tank 1 from the inlet 5 for a predetermined length.

Further, the upper end side 50a of the guide plate 50 is higher than the free surface 8 of the liquid to be treated contained in the separation device 1. Further, the downstream end portion 50b of the guide plate 50 extends to the farthest point in a straight line from the outlet 9. At the same time, this downstream end portion 50b is separated from the inlet 5 by 90 degrees or more along the swirling flow direction of the liquid to be treated (indicated by θ in this embodiment). The effect of the present invention can be obtained if the downstream end 50b is separated from the inlet 5 by about 90 degrees or more along the swirling flow direction of the liquid to be treated, and it is not necessarily the point at which the straight distance from the outlet 9 is the farthest. There's no need.

Further, the upper end side 50a of the guide plate 50 is the free surface 8 of the liquid to be treated.
Although it is preferable that the upper end side 50a be higher than the free surface 8, the effect of the present invention can still be obtained even if the upper end side 50a is lower than the free surface 8.

In this embodiment, the lower end side of the guide plate 50 is connected to the bottom wall 3.

Next, the operation of this solid-liquid separator will be explained.

The liquid to be treated that has flowed into the separation tank 1 from the inlet 5 is surrounded by the guide plate 50 and the side wall 2 and rotates while being guided by these.
It leaves the restraint of the guide plate 50 at the point where the straight distance from the outlet 9 is the farthest.

Therefore, even if the centrifugal force is small, the liquid to be treated does not take the shortest route to the outlet 9 as in the conventional case, but rotates sufficiently, and during this time, the floating solids 21 move onto the free surface 8 of the liquid to be treated. As the solids 20 rise to the surface, they settle in the direction of the bottom wall 3, maintaining a high separation rate.

The sedimentary solids 20 that have settled on the bottom wall 3 are collected in the recess 40 by the slope of the bottom wall 3, and are led out to the outside by operating the sand pump 41 as appropriate.

On the other hand, the floating solids 21 floating on the free surface 8 are guided into the overflow pipe 30 from the upper opening thereof, and are led out through the overflow pipe 30 to the outside.

The concentrated liquid from the overflow pipe 30 and the discharge pipe 42 containing a large amount of solid matter is sent to a sewage treatment plant, and the treated liquid after solid matter has been separated is discharged into a river etc. through the discharge port 9. It is.

FIG. 2 is a diagram showing a second embodiment of the present invention.
FIG. 3A is a plan view, and FIG.

This embodiment shows an example in which the separation tank 1 is used as a sand settling basin.

This embodiment is different from the embodiment shown in FIG. 1 above, in that an overflow pipe 30 as shown in the embodiment shown in FIG. is provided above the inflow channel 4, and the structure of the guide plate 50 is different.

Here, the length of the guide plate 50 is made longer than in the previous embodiment, and the downstream end portion 50b extends to a position approximately 180 degrees from the inlet 5. Further, the upper end side 50a of this guide plate 50 is configured to be above the free surface of the liquid to be treated as in the embodiment shown in FIG. 3, and a gap 50d is formed.

Then, the liquid to be treated containing sand flows into the separation tank 1 from the inflow path 4, is guided by the guide plate 50, and flows through the separation tank 1 for about 18 minutes.
After turning the chest 0 degrees, the person leaves the restraint of the guide plate 50.

Therefore, even if the centrifugal force in the liquid to be treated is small, the sand will settle sufficiently and a high separation rate can be obtained.

The sand constituting the sedimentary solid matter 20 that has settled on the bottom wall 3 is
are collected in the recess 40 by the slope of the sand pump 41
is extracted to the outside by operating the system appropriately.

Here, since a gap 50d is formed at the lower end of the guide plate 50, the sedimentary solids 20 that have settled directly below the inlet 5 can also move to the recess 40 through the gap 50d.

After the solid matter has been separated, the treated liquid is discharged into a river or the like through the discharge port 9 on the inflow path 4.

〔Effect of the invention〕

As explained in detail above, according to the solid-liquid separation device according to the present invention, even if the device becomes larger and the centrifugal force of the liquid to be treated swirling in the separation tank becomes smaller, The liquid to be treated that flows into the tank is guided by the guide plate and swirls along the side wall of the separation tank, so the distance traveled by the liquid from the inlet to the outlet is not reduced and sufficient solid-liquid separation is achieved. rate is maintained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a solid-liquid separator according to an embodiment of the present invention, in which (a) is a plan view and (b) is a plan view.
), and FIG. 2 is a diagram showing a second embodiment of the present invention, and FIG. 2(a) is a plan view, and FIG. 2(b)
3 is a top sectional view taken along the line ■-I in FIG. 3(a), and FIG. 3 is a diagram showing a conventional solid-liquid separation device. ) is a top sectional view taken along line I-I of FIG. In the figure, 1... separation tank, 2... side wall, 3... bottom wall,
5... Inlet, 8... Free surface, 9... Outlet,
50... Guide plate, 50a... Upper end side, 50b...
the downstream end. Applicant Ebara Corporation (1 other person) Agent Patent attorney Takashi Kumagai (1 other person); Yoi Figure 2 (b) 3rd person? to 4

Claims (1)

[Scope of Claims] A solid-liquid separator having a separation tank that performs solid-liquid separation while swirling a liquid to be treated introduced and stored inside a cylindrical container having a bottom wall, comprising: and an outlet for guiding the treated liquid after separation treatment to the outside of the separation tank. The discharge port is disposed at a position 180 degrees or more away from the inflow port along the swirling flow direction of the liquid to be treated, and the flow of the liquid to be treated flowing from the inflow port is directed to the separation tank. A solid-liquid separator characterized in that a guide plate is provided upright to guide the liquid along the side wall, and the downstream end of the guide plate is separated from the inlet by 90 degrees or more along the swirling flow direction of the liquid to be treated. .