JP3374304B2 - Scum processing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention crushes scum generated in a first settling basin or a final settling basin as a facility for purifying sewage by precipitating and removing flocculate solids and flocs floating in sewage. It relates to a processing device.

[0002]

2. Description of the Related Art Scum generated in a final sedimentation tank at a sewage treatment plant is removed by a pipe skimmer or a pump.
A system that dehydrates after concentration is effective, and its track record has already been confirmed. That is, the removed low-concentration scum (scum water) is concentrated by the scum separator by the pressure floating process, dehydrated by the dehydrator, and disposed. Then, the desorbed liquid from the scum separator and the dehydrated filtrate from the dehydrator are finally returned to a water treatment system such as a sand basin or a first sedimentation basin.

[0003]

However, the amount of scum generated varies with the seasons, and the concentration and dehydration operations of the scum require a large amount of equipment and are extremely troublesome. Further, although the amount of scum generated is relatively small, scum treatment equipment including a pressure flotation treatment device and a dehydration device is expensive, and facility operators tend to hesitate to introduce the scum treatment equipment. The present invention solves the above-mentioned problems of the prior art, scatters scum pumped by a pipe skimmer or pumped by a pump, forcibly removes air bubbles in the scum, and then settles. It is an object of the present invention to provide a simple scum treatment device which replaces conventional scum treatment equipment by returning sewage containing scum to a sand basin or a first settling basin and performing sludge treatment together with excess sludge.

[0004]

In order to achieve the above object, the present invention provides a scum treatment tank for receiving scum water containing scum generated in a final settling basin, and a scum water tank having an open bottom and an upper side. A scum crushing tank having an inflow port, the lower part of which faces the inside of the scum treatment tank, and a stirring blade for scum crushing which is installed on the surface of the scum water and is rotated by power from a power source. A scum treatment device is provided at the bottom of the scum treatment tank, which is provided with a scum discharge port for taking out sewage containing scum that has settled due to the separation of air bubbles due to crushing.

The surface of the scum water in the scum treatment device is preferably the overflow portion at the upper end of the scum treatment tank. Further, it is effective to provide a dispersion plate for dispersing the inflowing scum in the scum crushing tank. Further, it is more effective to provide a scum cage with a coarse mesh for removing solid matter that does not sediment coarsely at the inlet of scum water in the scum crushing tank.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1A is a vertical sectional view showing an embodiment of a scum treating apparatus according to the present invention.
FIG. 3B is a plan view of the dispersion plate. Scum generated in the final settling tank is removed by a pipe skimmer or pump (not shown). For example, to remove scum with a pipe skimmer, use the return flight above the water surface of a flight-type sludge scraper to scrape the scum up to the pipe skimmer, and periodically rotate (fall) the notched pipe to make a cutout. Overflowing from a part, scum on the water surface is put only in the pipe together with the overflowed water, and it is pumped to a scum storage tank by a separate pump. In addition, scum removal by a pump directly sends scum water containing scum pumped by the pump to a scum storage tank.

The scum water 2 sent from a scum storage tank (not shown) flows in through an inlet 21 formed on the upper side of the scum crushing tank 20 constituting the scum processing apparatus 1, and scum also constituting the scum processing apparatus 1. It is sent to the processing tank 10.

The scum treatment tank 10 has a cylindrical upper side,
It is a container made of a rust preventive material such as stainless steel having a conical lower side, and a recovery tank 11 for receiving overflowed scum water is provided at an upper side edge thereof.

The scum crushing tank 20 is a cylindrical container made of a rust preventive material such as stainless steel, the bottom is opened, and the lower part is immersed to a position reaching the midway area of the scum treatment tank 10. .

The level of the scum water in the scum crushing tank 20 may be at any position as long as it is above the lower end of the scum crushing tank 20, but in this embodiment, it is at the upper end of the scum crushing tank 10. The position of the overflow portion is shown. A stirring blade 30 for crushing scum, which constitutes the scum treatment device 1, is provided at a position directly above the surface of the scum water. The shaft 31 of the stirring blade 30 has a scum crushing tank 2
It is connected to an output shaft (not shown) of the electric motor 32, which is a power source attached to the upper part of 0, and is rotated by the power.

In the scum crushing tank 20, a scum basket 22 is provided at the inlet 21 of the scum water 2, and an inflowing scum water is provided between the inlet 21 of the scum water 2 and the stirring blade 30. A dispersion plate 23 having a large number of holes 23a is provided.

Further, at the bottom of the scum treatment tank 10, a scum discharge port 12 for taking out the sewage 3 containing the settled scum is openably and closably provided.

The processing means of the scum processing apparatus 1 having the above-mentioned structure will be described. First, of the solids contained in the scum water 2 flowing from the inflow port 21 on the upper side of the scum crushing tank 20, for example, fruit seeds. Relatively coarse, like
Those that do not settle are separated and removed by the scum cage 22 having a coarse mesh.

The scum water that has passed through the scum basket 22 is dispersed by the dispersion plate 23 and uniformly drops toward the scum treatment tank 10. Since the scum in the scum water has bubbles inside, the scum floats above the surface of the scum water. Particularly in scum caused by actinomycetes, an oily substance generally called mycolic acid surrounds air bubbles, and it is often not degassed by the stirring action when pumping scum water. These scums are stirred in the scum treatment tank 10 by the inflow of scum water to the scum treatment device 1, and thus float in a constant depth section (floating section A in the figure) near the surface of the scum water. When the inflow of scum water is stopped when the scum treatment tank 10 is almost filled, the floating scum gradually rises above the surface of the scum water while being pushed up from the lower layer. The scum water overflowing from the upper end of the scum treatment tank 10 is recovered in the recovery tank 11,
It is returned to the sand basin or the first sedimentation basin. The floating scum is crushed by the stirring blade 30 provided at a position directly above the water surface, and the air bubbles are forcibly removed according to the fragmentation and settle at the bottom of the scum treatment tank 10. When the scum is crushed on the water surface and degassed and settles, the scum below the water surface gradually rises and the crushing action is repeated.

When all the scum is crushed in the scum treatment tank 10, the sewage 3 containing the scum that has been degassed and settled at the bottom is taken out by opening the discharge port 12 and returned to the sand basin or the first settling basin. Sludge treatment is performed together with excess sludge.

When the first scum treatment is completed as described above, scum water is allowed to flow into the scum treatment tank 10 again from the aforementioned scum storage tank (not shown), and the crushing treatment is sequentially performed by the same process.

[0017]

According to the scum treatment device of the present invention having the above-mentioned structure, scum water which is only swallowed in the pipe by the pipe skimmer or pumped by the pump is introduced into the scum treatment device to remove the scum floating. The scum water is crushed by the stirring blade 30 provided immediately above the surface of the water to forcibly remove the bubbles in the scum, and then the sewage containing the settled scum is returned to the settling basin or the first settling basin. Since sludge treatment is performed together with excess sludge, there is no need for concentration and dewatering operations using conventional scum treatment equipment including a pressure flotation treatment device and dewatering device, and a simple and low-cost scum treatment device can be obtained. .

[Brief description of drawings]

1A is a vertical cross-sectional view showing an embodiment of a scum treatment device according to the present invention, and FIG. 1B is a plan view of a dispersion plate of the same device.

[Explanation of symbols]

1… Scum processing device 2 ... scum water 3… Sewage 10… Scum processing tank 11… Collection tank 12… Scum outlet 20 ... Scum crushing tank 21 ... Inlet 22 ... scum basket 23 ... Dispersion plate 23a ... hole 30 ... Stirrer 31 ... Axis 32 ... Electric motor

Claims (4)

(57) [Claims] 1. A scum treatment tank for receiving scum water containing scum generated in a final settling tank, an open bottom and an inlet for the scum water on the upper side, and a lower part facing the inside of the scum treatment tank. It consists of a scum crushing tank and a stirring blade for scum crushing, which is installed on the surface of the scum water and is rotated by the power of a power source.At the bottom of the scum treatment tank, internal bubbles are released due to crushing. A scum treatment device provided with a scum discharge port for taking out sewage containing sedimented scum. 2. The scum treatment device according to claim 1, wherein the surface of the scum water is an overflow portion at the upper end of the scum treatment tank. 3. The scum processing device according to claim 1, wherein the scum crushing tank is provided with a dispersion plate for dispersing the inflowing scum. 4. The scum treatment according to any one of claims 1 to 3, wherein a scum basket having a coarse mesh for removing solid matters not settling coarsely is provided at an inlet of scum water in the scum crushing tank. apparatus.