JPS6339314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a water treatment apparatus using an oxidation date method, particularly to the structure around an aerator.

The oxidation date method is to install an oblong circulation waterway, and use a mechanical aerator to circulate sewage and sludge containing microorganisms in the circulation waterway to aerate the microorganisms. This is an activated sludge treatment method that treats water by decomposing organic matter in sewage. In such a treatment method, it is necessary to sufficiently stir the sludge containing microorganisms and incoming sewage (sewage, etc.) in the circulating waterway, and to supply a certain amount of oxygen.

Therefore, a rotor-type aerator as shown in Figure 1 is generally used, but such a rotor-type aerator has a poor exchange rate of circulating water between the surface and bottom of the circulation waterway, and Since the flow speeds of the circulating water were significantly different (see flow speed line V), stirring of the sludge and sewage, which had different specific gravities, was insufficient. Therefore, as shown in Figure 2, by improving the exchange rate of circulating water between the surface and bottom of the circulation waterway, the difference in flow velocity between the surface and bottom can be reduced (see flow velocity line V) and the sludge and sewage can be agitated. Vertical shaft type surface aerators with improved efficiency came into use. However, in the case of the above-mentioned vertical axis type surface aerator, although the exchange rate of circulating water between the surface and the bottom is improved compared to the rotor type, it is still not sufficient. During aeration, some of the sewage is scattered in a direction that obstructs the flow of the circulation waterway, thereby impairing the flow of the circulation waterway.

The present invention was made in view of the above-mentioned current situation, and aims to provide a water treatment device with excellent agitation and circulation efficiency by attaching a means for increasing the agitation and circulation efficiency around a vertical shaft type aerator. purpose.

Therefore, the water treatment device according to the present invention has the following configuration. That is, a central separation wall is provided in the longitudinal direction of the oval aeration tank to form a circulation waterway, and a vertical axis type surface aerator is installed adjacent to one end of the central separation wall to circulate sewage within the waterway. In water treatment equipment that processes activated sludge by aerating and circulating
A columnar area vertically below the water, including the rotating surface of the blades attached to the lower end of the vertical axis type surface aerator, is surrounded by a water pump, and an opening is provided at the lower end of the water pump on the side of the central separation wall. This structure is designed to guide the wastewater flowing at the bottom to the surface, and by providing a guide plate in a part of the periphery of the aeration space above the water surface, it is possible to prevent wastewater from scattering in a direction that obstructs the flow of the circulation channel during aeration. By changing the direction in the same direction as the circulation, the flow of the circulation channel is improved.

Hereinafter, the present invention will be specifically described based on examples and with reference to the drawings.

Fig. 3 is a plan view of the entire water treatment device according to the present invention, Fig. 4 is a partial side sectional view of the same showing the flow of circulating water around the water pump, and Fig. 5 is a water pipe with a guide plate installed. It is the same top view showing the state of scattering of surrounding sewage. In the figure, 1 is a circulation waterway, 2 is a central partition wall, 3 is a vertical shaft type surface aerator, 4 is a water pump, and 5 is a guide plate. The circulation waterway 1 is formed by installing a central separation wall 2 in the longitudinal direction of an aeration tank which is oval in plan view. The vertical shaft type surface aerator 3 has an aeration blade 3a attached to the lower end of a rotating shaft driven by an electric motor installed above. The water pumping cylinder 4 has a cylindrical outer shape, the height H of the cylindrical body approximately corresponds to the water level of the circulation channel, and the inner radius R of the cylindrical body is slightly larger than the outer radius r of the aerator blade. It is large and has an opening 4 in a part of the lower end of the cylindrical body.
a, 4b are formed, and the guide plate 5 is formed of a plate-like body formed in a curved plane substantially arcuate.

Therefore, in this water treatment device, the above-mentioned vertical axis type surface aerator 3 is installed adjacent to one end of the central separation wall 2 at the curved part of the circulation waterway 1 (see Figs. 3, 4, and 5). ), vertically below the rotating surface of the blades 3a of the aerator 3, place the water pumping tube 4 in such a manner that its upper end surrounds the blade 3a, and its lower end is in contact with the bottom surface of the circulation waterway. , and the lower end opening 4
a, 4b face the central separation wall 2 side, and the opening 4
The center partition wall is installed so that it is located between a and 4b (see Figures 3, 4, and 5), and the area around the aeration space of the aerator 3 is placed above the water surface. A guide plate 5 is attached to the section (inflow side) (see Figs. 4 and 5). The aerator may be attached to the aerator via a fitting, or it may be attached to the central separation wall 2.

The present water treatment apparatus configured as described above operates as follows when treating activated sludge. That is, when sewage containing organic matter and sludge containing microorganisms are mixed into the circulation waterway, the blades of the aerator scatter the sewage containing the sludge into the air, and this scattering causes oxygen to be mixed into the sewage. So-called aeration is performed. As the blades of the aerator rotate, the sewage on the inside surface of the pumping cylinder is blown out of the pumping cylinder, so the sewage flowing at the bottom is sucked into the pumping cylinder through the opening formed at the lower end of the pumping cylinder. The water is sucked up along the side wall and thrown out of the tank by the blades of the aerator, and the cycle repeats (see Figure 4). At this time, the sewage that is scattered by the blade in a direction that obstructs the flow of the circulation waterway collides with the guide plate 5,
It turns in the same direction as the flow of the circulation waterway and falls onto the sewage surface (see Figure 5). Incidentally, more wastewater than the above-mentioned scattering flows into the opening at the lower end of the water pump, but the wastewater other than the above-mentioned scattering flows into the openings 4a to 4b formed on the opposite side across the central separation wall.
The water is bypassed and flows out of the pumping cylinder.

As mentioned above, in this water treatment equipment, the wastewater flowing at the bottom of the circulation channel is sucked up to the surface and scattered by the water pump, and then gradually descends to the bottom due to the difference in specific gravity during circulation. The difference between the flow rate of wastewater at the bottom and the bottom part is reduced, and the wastewater can be sufficiently agitated. Further, by providing the guide plate, the wastewater is not scattered in a direction that obstructs the flow of the circulation waterway, so the circulation efficiency is improved. According to experiments conducted by the applicant, it has been confirmed that the circulation efficiency is improved by about 20% compared to conventional devices.

As explained above, although the present invention has a relatively simple configuration, it has significant effects and contributes to improving the processing efficiency of the oxidation date method.

[Brief explanation of the drawing]

Figure 1 shows a conventional water treatment system equipped with a rotary aerator, Figure 2 shows a conventional water treatment system equipped with a vertical axis type surface aerator, and Figure 3 shows the entire water treatment system according to the present invention. FIG. 4 is a partial side sectional view of the same, and FIG. 5 is a plan view of the same. 1... Circulation channel, 2... Central separation wall, 3... Vertical axis type surface aerator, 3a... Blade, 4... Water pump, 4a, 4b... Opening, 5... Guide plate.

Claims (1)

[Claims] 1. A central separation wall is provided in the longitudinal direction of the oval aeration tank to form a circulation waterway, and a vertical shaft type surface aerator is installed adjacent to one end of the central separation wall to drain sewage within the waterway. In a water treatment device that processes activated sludge by aeration and circulation, a columnar area vertically below the water, including the rotating surface of the blade installed at the lower end of the surface aerator, is surrounded by a pumping tube, and the pumping tube An opening is provided at the lower end of the central separation wall to guide wastewater flowing at the bottom to the surface, and a guide plate is provided at a portion of the periphery of the aeration space above the water surface to facilitate aeration during aeration. A water treatment device characterized in that it is configured to improve the flow of the circulation waterway by diverting the wastewater that is scattered in a direction that impedes the flow of the circulation waterway to the same direction as the circulation.