JPS6310861Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a scum discharge device for a circular sedimentation tank or the like.

Generally, a circular sedimentation tank or a circular thickening tank is equipped with a scum discharge device that scrapes up scum with a skimmer arm supported by a drive shaft or scraper for sludge scraping and discharges it to a scum box. There is.

Figures 1 and 2 show typical examples of conventional circular sedimentation tanks, which include a system for supplying raw water to be treated to the center of the tank and evenly distributing incoming raw water radially within the tank. A center well 1 is provided, but since scum remains in this center well 1, it is necessary to remove it.

In the figure, 2 is the drive device, 3 is the rotating shaft, 4 is the skimmer arm, 5 is the skimmer blade, 6 is the scum box, 7 is the scum discharge pipe, 8 is the rake arm, 9 is the rake, 10 is the outflow pipe, and 11 is the raw water inflow. The tube 12 is a baffle plate.

The object of the present invention is to provide a device for accurately discharging the scum inside the centawell to the outside thereof.

The present invention is a scum discharge device that uses a skimmer blade to discharge scum floating on the water surface of a circular sedimentation tank or a circular concentration tank in which a centawell is arranged near the center of the tank. A diaphragm is provided, and several openings are bored in the circumferential direction near the water surface of the diaphragm and the centawell, and one of the centawell and the diaphragm is fixed and the other is rotated. A scum discharge device is available.

An embodiment of the present invention will be described with reference to FIGS. 3 and 5. An annular partition plate 22 is disposed concentrically inside a cylindrical centerwell 21. Both the center well 21 and the partition plate 22 are open at both upper and lower ends, and a plurality of openings 24 and 25 are provided at the same height near the water surface 23 at approximately equal angular pitches in the circumferential direction. These shapes, dimensions, and numbers are the same, and Centawell 21
is indirectly fixed to the inner wall of the sedimentation tank, whereas the partition plate 22 is attached to the rotating shaft 3 via a member 26 and is rotatable. In addition, in FIG. 3 (the same applies to FIG. 4, which will be described later), the scum box, scum discharge pipe, etc. are omitted.

Therefore, when the rotating shaft 3 is rotated, the partition plate 22 is also rotated, and when the openings 25, 25, . . . coincide with the openings 24, 24, . It flows out to the outside and is discharged into the scum box by the skimmer blade 5. In this case, the plurality of openings simultaneously
And the cycle of fully closed → start of opening → fully open → start of closing → fully closed is repeated, so Ceautauer 21
Scum can be discharged evenly throughout the interior.

Next, in the example shown in FIG. 4, contrary to the example shown in FIG. It is introduced below the inner water surface of the centawell 21 from the inner upper part of the center well 22. Note that the skimmer blade 5 is attached to the rake arm 8 via a member 30 so as to be rotatable.

The operation of this embodiment will be apparent from FIG.

In any case, the present invention may be of any structure as long as the centawell and the partition plate are moved relative to each other and their respective openings are aligned to discharge scum. Note that the amount of scum flowing out can be adjusted by appropriately setting the number and size of the openings.

As described above, the device of the present invention can form a scum discharge port intermittently by rotating the rotating shaft, and since the opening is not always open, it may cause shortfalls due to the outflow of surface water from the centawell. This also effectively prevents the problem of deterioration of treated water, and since there are no sliding parts for opening and closing the opening, there are practical benefits such as no maintenance required.

[Brief explanation of the drawing]

Figure 1 is a plan view of the conventional example, Figure 2 is a sectional view of Figure 1, Figure 3 is a sectional view of an embodiment of the present invention, and Figure 4 is a sectional view of an embodiment of the present invention.
The figure is a sectional view of another embodiment, and FIG. 5 is a perspective view for explaining the operation of each of the above embodiments. 5... Skimmer blade, 21... Centawell, 22... Partition plate, 23... Water surface, 24, 25...
…Aperture.

Claims (1)

[Scope of utility model registration request] In a scum discharge device that uses a skimmer blade to discharge scum floating on the water surface of a circular sedimentation tank with a centawell near the center of the tank or a circular concentration tank,
A concentric diaphragm is disposed inside or outside the centawell, and several openings are bored in the circumferential direction near the water surface of the diaphragm and the centawell. A scum discharge device in which one of the devices is fixed and the other is rotatable.