JPH0378121B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sedimentation tank suitable for treating various types of polluted water.

Generally, methods for separating suspended particles in polluted water include a flotation method and a sedimentation method. In these methods, the sedimentation rate of suspended particles is the most important point. Sedimentation of suspended particles becomes more efficient as the surrounding water flow becomes more rectified and more uniform. Suspended particles that are carried away by the flow velocity float or settle, but other light and small particles are not separated. In order to float or settle these floating fine particles, it is necessary to reduce the flow rate of the sedimentation tank or slow down the flow rate to increase the residence time in the sedimentation tank. However, in order to satisfy these conditions, it is necessary to increase the area and volume of the settling tank.

The present inventor reduced the scale of the settling tank as much as possible,
The present invention was completed as a result of various research into a sedimentation tank that has a high flow rate relative to the water flow rate, shortens the residence time in the sedimentation tank, and has a high separation efficiency for suspended particles.

That is, in the present invention, partition plates are provided at intervals above the sedimentation tank, a plurality of partition plates are further provided between the partition plates, the lower ends of the partition plates are extended downward from the lower ends of the partition plates, and the sedimentation tank is A sedimentation tank characterized in that a shielding plate having a gap is provided at the bottom of the tank between the partition plates, and a lower part of the partition plate and an upper part of the shielding plate overlap with each other.

Next, the present invention will be explained with reference to the drawings.

Partition plates 2 are provided at intervals on the upper part of the settling tank 1, and a plurality of partition plates 3 are further provided between each partition plate 2.
will be established. It is necessary that the lower ends of the partition plate 2 and the partition plate 3 are both located below the water level of the settling tank. The lower end of the partition plate 2 is provided to extend downward from the lower end of the partition plate 3.
Further, a shielding plate 4 is provided at the bottom of the settling tank so as to be located between each of the partition plates 2. As is clear from the drawings, it is necessary that the lower end of the partition plate 2 and the upper end of the shield plate 4 overlap as shown by h. The degree of overlap may be appropriately selected depending on the nature of the polluted water to be treated. This shielding plate 4 has a porous or slit-like cavity 5.

Further, the settling tank 1 of the present invention is provided with a scraper 6 that can be moved from side to side between the partition plates 2 and 3 or between the partition plates 3 and 3. Furthermore, it is preferable to provide a flocculant injection pipe 8 and an aeration pipe 9 in the polluted water introduction section 7 of the settling tank. Further, the settling tank 1 of the present invention is provided with scum pockets 10 on both sides, as shown in FIG.

According to the sedimentation tank configured as described above, when polluted water passes through the gap 5 of the shielding plate 4 provided at the bottom of the sedimentation tank 1, it appears to be blown out. The phenomenon facilitates the separation of pollutant particles in polluted water. In addition, when the polluted water flowing in from the polluted water introduction part 7 passes through the settling tank 1,
Since the lower end of the partition plate 2 and the upper end of the shielding plate 4 overlap, the residence time in the sedimentation tank is increased due to the detour flowing between them, thereby increasing the separation efficiency of the pollutant particles.

Next, a treatment method using the settling tank 1 of the present invention will be explained.

The polluted water (not shown) that has entered the polluted water inlet 7 of the settling tank 1 is injected with a coagulant from a coagulant injection pipe 8, and air is introduced from an aeration pipe 9. When the thus treated polluted water passes through the space between the partition plate 2 and the shielding plate 4, or through the gap 5 of the shielding plate 4, the polluted particles in the polluted water are separated and floated to the surface. Further, since the water surface portion of the settling tank 1 is divided by the partition plates 2 and 3, a static zone layer is formed in this portion, and the efficiency of separating pollutant particles is increased. Separated and floated contaminant particles (scum) are collected between the partition plate 2 and the partition plate 3 or between the partition plate 3. The collected scum is scraped into scum pockets 10 provided on both sides of the sediment layer by the left and right movement of a scraper 6 provided at the top of the sedimentation tank 1. The collected scum is removed outside the sediment layer. On the other hand, the treated water from which pollutant particles have been removed after passing through the sedimentation layer is sucked up by a pump and sent to the discharge pipe 1.
1 is discharged to the outside of the sediment layer.

As described above, the sedimentation layer of the present invention allows efficient treatment of polluted water.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of the settling tank of the present invention,
FIG. 2 is a schematic vertical sectional view thereof.

Claims (1)

[Claims] 1. Partition plates are provided at intervals in the upper part of the sedimentation tank, and a plurality of partition plates are further provided between each partition plate, and the lower end of the partition plate is extended downward from the lower end of the partition plate,
A settling tank characterized in that a shielding plate having a gap is provided at the bottom of the settling tank between the partition plates, and a lower part of the partition plate and an upper part of the shielding plate overlap each other. .