JPH0311802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 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.

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 conducted by guiding wastewater. When the weather is clear, only sewage is channeled, and pollutants are removed at the treatment plant, resulting in clean water that is then released into the river. During rainy weather, especially when heavy rain suddenly occurs, a rainwater discharge chamber is installed at an appropriate location along the route leading to the pumping station or treatment plant, and the relatively clean supernatant rainwater is gradually released into the river. The water is discharged, and the remainder is sent to a pump station or treatment plant.

The capacity of a sewage treatment plant is usually the flow rate of sewage on a sunny day, q.
It is now possible to treat sewage with a flow rate of about 3q, which is three times the amount of wastewater. In the case of heavy rain, the amount of water that flows into the sewers far exceeds this 3q, so as mentioned above, the excess amount is overflowed from the rainwater outlet and discharged into the river, and the amount of water to be treated that goes to the sewage treatment plant is limited to 3q. However,
A large amount of contaminated overflow water flows into rivers, causing problems of water pollution and environmental pollution, and solving this problem has become one of the most urgent and important issues in sewerage systems.

An object of the present invention is to provide a solid-liquid separator that can eliminate the above-mentioned drawbacks of the conventional devices and prevent river pollution.

The present invention provides a solid-liquid separator having a separation tank having a side wall and a bottom surface and performing solid-liquid separation while swirling a liquid to be treated contained therein. The inflow port and the outflow port are both part of the side wall. or a part of the bottom surface,
The solid-liquid separator is characterized in that the discharge port is located at a position 180 degrees or more away from the inflow port along the swirling flow direction of the liquid to be treated.

Embodiments of the present invention will be described using the drawings.

In FIGS. 1a and 1b, a separation tank 1 has a side wall 2 and a bottom surface 3 that are approximately circular (circular, oval, oval, similar circular shape, or spiral shape). An inlet 5 of an inflow pipe 4 is provided in the side wall 2 of the separation tank 1 so as to introduce the liquid to be treated tangentially to the side wall 2 and give swirling motion to the liquid in the separation tank 1. The inlet 5 may be partially located on the bottom surface 3, or may be located only on the bottom surface 3. The bottom surface 3 is inclined from the outer periphery toward the center. The bottom surface 3 may be formed as a horizontal surface, but it is more effective to have an inclined surface in order to accumulate precipitable solids at the center of the bottom surface.

A bottom discharge pipe 6 is provided near the center of the bottom surface 3 of the separation tank 1 as a concentrated liquid discharge part for guiding the separated concentrated liquid containing a large amount of solids to the outside of the tank. As will be described later, the liquid is accumulated at the bottom by swirling flow and secondary flow, and is discharged to the outside of the tank together with the liquid to be treated as a concentrated liquid. Also separation tank 1
When the amount of liquid flowing into the tank decreases, the solid liquid stored in the tank is discharged to the outside of the tank.

A discharge port 9 is provided in the side wall 2 of the separation tank 1 . This outlet 9 is preferably provided at a position of 180 degrees or more from the inlet 5 along the flow direction around the side wall 2. The outlet 9 may be located partially on the bottom surface 3, or may be located only on the bottom surface 3.

A discharge waterway 10 having an overflow weir 11 as an overflow mechanism is provided downstream of the discharge port 9.
The height of the overflow weir 11 is set higher than the upper edge of the outlet 9. Preferably, the height of the overflow weir 11 is variable so that the flow rate can be adjusted.

The downstream side of the overflow weir 11 is connected to a river or the like.
When the amount of rain increases and the amount of water exceeds the amount that can be treated at a sewage treatment plant, it is possible to remove pollutants and release it into rivers, etc.

The operation of the embodiment as described above will be explained.

The sewage that has flowed into the separation tank 1 from the inlet 5 via the inflow pipe 4 circulates in the tank as a swirling flow in the direction of arrow 22, during which floating solids float to the water surface and settle. The solids settle on the bottom surface 3.

The solid matter deposited on the bottom surface 3 is gradually gathered to the center by gravity due to the slope of the bottom surface 3, and is discharged from the bottom discharge pipe 6.

The fluid that has flowed in from the inlet flows out from the outlet 9 through the trajectory shown by the solid line A in FIG. 2b. However, if the specific gravity of the solids that flowed in with the liquid is greater than the liquid, the solids will deviate from the liquid trajectory A, pass below the outlet 9, and settle on the bottom surface 3, as shown by the dashed line C. do. On the other hand, if the specific gravity is small, it passes above the outlet 9 and floats to the liquid surface as shown in trajectory B.

The larger the difference between the specific gravity of the solid and the specific gravity of the liquid, the farther the trajectory C of the solid is from the outlet 9.
The probability that solid matter will not flow out from the outlet 9 increases. Furthermore, the farther apart the inlet 5 and outlet 9 are, the greater the degree of sedimentation or floating between them, so the rate at which solids are separated from the liquid increases. The center position of the outlet 9 is preferably separated from the inlet 5 by θ=180 degrees or more in the direction of the swirling flow with the center of the tank as the center.

In Fig. 2a, if the solid passes radially inward like the trajectory E compared to the trajectory D of the liquid,
The separation rate increases accordingly.

The concentrated liquid containing a large amount of solids is sent to a sewage treatment plant by the concentrated liquid discharge mechanism, and the treated liquid after the solids have been separated is discharged into a river or the like through the discharge port 9. The load on the sewage treatment plant is reduced by the amount that flows out from the outlet 9.

In a combined sewer system, when it begins to rain and the amount of sewage increases rapidly, solids that were stagnant in the sewer pipes during clear weather generally begin to flow out all at once. At this time, a large amount of solids flows into the separation tank 1, which was empty until then, along with the liquid, but if the overflow weir 11 is not provided, the liquid level will still reach above the outlet 9. If not, the solids will flow out into the river through the outlet 9. Therefore, an overflow weir 11 is provided downstream of the outlet 9 as an overflow mechanism so that the liquid can flow out after the liquid level reaches a position sufficiently higher than the upper edge of the outlet 9.

As an overflow mechanism, even if it is not an overflow weir 11,
As shown in FIG. 3, the outlet waterway 1 downstream of the outlet 9
0 as a conduit, and an overflow conduit in which the position of the open end 14 of the conduit is variable up and down. If a valve is installed downstream of the outlet to adjust the flow rate,
Unseparated solids may clog the valve, which is undesirable.

If the flow rate is adjusted by adjusting the overflow height of an overflow mechanism such as an overflow weir or an overflow pipe as described above, solid matter will not become clogged.

The stabilizer plate 13 in FIG. 3 is for preventing flow sloshing.

In order to discharge the solid matter having a low specific gravity floating on the liquid surface, a structure having a wall lower than the liquid free surface 8 and having an open upper end as shown in FIGS. 4a and 5b or 5a and 5b is used. An overflow pipe 7 whose lower end communicates with the outside of the tank is provided as an overflow part. It is better to install the overflow pipe 7 vertically in the center of the separation tank 1 as shown in FIG. 5 so that the flow will not be obstructed, and due to the swirling flow inside the tank, it will descend along the side wall 2 as shown by the arrow 23. , creating a secondary flow that flows towards the center along the bottom surface 3. The solids that have settled on the bottom surface 3 tend to gradually collect due to gravity due to the slope of the bottom surface 3, but this secondary flow collects them in the center in a shorter time and allows them to be collected more effectively than the concentrate discharge section. It is discharged.

As a concentrate discharge part, a discharge port 15 for discharging the precipitated solids may be provided in the lower pipe wall of the overflow pipe 7 as shown in FIG. 5b, or as shown in FIGS. 6a and 6b. A separate bottom discharge pipe 6 may be provided, and a bottom discharge port 15 may be provided near the center of the bottom surface. There may be a plurality of bottom outlets.

As an overflow part, instead of the overflow pipe 7, a part or all of the side wall 2 is made lower than the liquid free surface 8, as shown in FIGS.
From step 6, solid matter floating on the liquid surface may be discharged.

The shape of the separation tank 1 does not necessarily have to be nearly circular; for example, a rectangular shape as shown in FIG. 5 or another shape may be selected as appropriate.

The outlet 9 may be provided only on the bottom surface 3 as shown in FIG. Both the outlet 9 and the inlet 3 may span a part of the side wall 2, a part of the bottom surface 3, or both.

Furthermore, the partition plate 17 shown in FIG. 6 is used to prevent the flow of the inflow liquid from weakening and to generate a strong swirling flow.

In the case shown in FIG. 7, the inlet pipe 4 is not tangential to the side wall 2, but the flow is directed tangentially by the partition plate 17.

FIG. 8 shows another embodiment in which a guide plate 18 is provided after the inlet 5 to guide the inflowing liquid to be treated inward away from the side wall 2.

In this way, the solids in the inflowing liquid to be treated swirl inside away from the side wall 2 along the guide plate 18 and do not pass near the outlet 9, thereby increasing the separation rate.

The flow that has passed near the outlet 9 is directed to the guide plate 1.
8 and flows near the side wall 2, but even if solid matter is mixed in the flow, it has sufficiently floated or settled, so there is little risk of it flowing out from the outlet 9. The cross-sectional shape of the guide plate 18 may be a flat plate, a rectangle, or the like in addition to the semicircular shape shown in the figure. Further, supports may be provided as necessary to increase the strength.

FIG. 9 shows another embodiment in which the inflow pipe 4 is attached not tangentially to the side wall 2, and a guide plate 18 is provided in the same direction as the inflow pipe 5 to direct the inflowing liquid to be treated from the side wall 2. It was designed to be separated and guided inward.

FIG. 10 shows another embodiment, in which the liquid to be treated enters in the tangential direction to the side wall 2 at the inlet 5 of the inflow pipe 4, but has already been separated from the side wall 2 and is moved by the guide plate 18 to the side wall. 2, so that it is directed so as to turn while staying away from it.

FIG. 11 shows yet another embodiment of the apparatus, which is suitable for separating floating solids, and when there are no sedimentable solids, there is no need for a bottom discharge part, and an overflow pipe is used as a concentrate discharge part. 7 will be provided. In addition, if another overflow part 19 is provided at a position higher than the level of the liquid to be treated and the downstream of this overflow part 19 is guided to a river etc., the level of the liquid to be treated will rise abnormally and the separation tank It is possible to prevent the risk of nearby facilities being flooded when water overflows from 1.

According to the present invention, the liquid to be treated containing solids can be
It is possible to provide a solid-liquid separation device that can efficiently and continuously carry out solid-liquid separation processing to prevent river pollution in sewage facilities, and can have extremely great practical effects.

[Brief explanation of drawings]

FIGS. 1 to 11 relate to embodiments of the present invention, in which a is a plan view, b is a vertical cross-sectional front view thereof, and FIG. 8c is a cross-sectional view taken along the line I--I of FIG. 8a. be. 1...Separation tank, 2...Side wall, 3...Bottom surface, 4...
...Inflow pipe, 5...Inflow port, 6...Bottom discharge pipe,
7... Overflow pipe, 8... Free surface, 9...
... Outlet, 10... Outlet channel, 11... Overflow weir, 13... Stabilizer, 14... Open end, 15...
Discharge port, 16... Upper edge, 17... Partition plate, 18...
...Guidance board, 22...arrow.

Claims (1)

[Scope of Claims] 1. In a solid-liquid separation device having a separation tank having a side wall and a bottom surface and performing solid-liquid separation while swirling a liquid to be treated stored therein, an inlet for the liquid to be treated; A discharge port that guides the treated liquid after treatment to the outside of the tank, and a concentrated liquid discharge part that leads a concentrated liquid containing a large amount of separated solids to the outside of the tank, and both the inflow port and the discharge port are connected to the side wall. or a part of the bottom surface, and the discharge port is located at a position 180 degrees or more away from the inflow port along the swirling flow direction of the liquid to be treated. A solid-liquid separation device characterized by: 2. In a solid-liquid separation device having a separation tank having a side wall and a bottom surface and performing solid-liquid separation while swirling the liquid to be treated contained therein, the inlet for the liquid to be treated and the treated liquid after separation treatment are provided. and a concentrated liquid discharge part that leads a concentrated liquid containing a large amount of separated solids to the outside of the tank, and the inflow port and the discharge port are both part of the side wall or provided on at least one of a part of the bottom surface, the discharge port is located at a position separated from the inflow port by 180 degrees or more along the swirling flow direction of the liquid to be treated, and the discharge port is provided following the discharge port. A solid-liquid separator comprising: a discharge waterway for guiding a treated liquid; and the discharge waterway is equipped with an overflow mechanism higher than an upper edge of the discharge port. 3. In a solid-liquid separation device having a separation tank having a side wall and a bottom surface and performing solid-liquid separation while swirling the liquid to be treated stored therein, an inlet for the liquid to be treated, and an inlet for the treated liquid after separation processing. and a concentrated liquid discharge part that leads a concentrated liquid containing a large amount of separated solids to the outside of the tank, and the inflow port and the discharge port are both part of the side wall or provided on at least one of a part of the bottom surface, the discharge port is located at a position separated from the inflow port by 180 degrees or more along the swirling flow direction of the liquid to be treated, and A solid-liquid separator characterized by having an overflow section through which a processing liquid overflows. 4. In a solid-liquid separation device having a separation tank having a side wall and a bottom surface and performing solid-liquid separation while swirling the liquid to be treated stored therein, the inlet for the liquid to be treated and the treated liquid after separation treatment. and a concentrated liquid discharge part that leads a concentrated liquid containing a large amount of separated solids to the outside of the tank, and the inflow port and the discharge port are both part of the side wall or provided on at least one of a part of the bottom surface, the discharge port is located at a position 180 degrees or more away from the inflow port along the swirling flow direction of the liquid to be treated, and A solid-liquid separator characterized by having a guide plate that guides the flow of a liquid to be treated inward away from a side wall.