JPS60114397A - Water treating device - Google Patents

Abstract

PURPOSE:To improve the stirring and circulating efficiency for sewage by providing an aperture in the bottom end part on the central separating wall side of a lifting cylinder to conduct the sewage flowing in the bottom to the surface and providing a guide plate to a part of the periphery of an aeration space on the water surface. CONSTITUTION:When sewage contg. org. material and sludge contg. microorganisms are put into a circulating water course 1, the blade 3a of an aerator 3 scatters the sewage contg. sludge into air and mixes oxygen into the sewage, thereby aerating the sewage. The sewage on the inside surface of a lifting cylinder 4 is scattered to the outside of the lifting cylinder with the revolution of the blade 3a of the aerator and therefore the sewage flowing in the bottom is sucked through an aperture 4b at the bottom end of the lifting cylinder into the cylinder 4 and is sucked up along the side wall thereof then the sewage is scattered to the outside of the lifting cylinder by the blade 3a of the aerator and such cycle is repeated.

Description

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

The oxidation ditch method is an oxidation ditch method in which an oblong circulation waterway is installed, and a mechanical aerator is used to circulate sewage and sludge containing microorganisms in the circulation waterway.
This is an activated sludge treatment method in which microorganisms decompose organic matter in sewage through aeration. In such a treatment method, it is necessary to sufficiently stir the sludge containing microorganisms and the incoming sewage (sewage water, etc.) in the circulating waterway, and to supply oxygen on a constant plate.

Therefore, a rotor-type aerator as shown in Figure 1 is generally used, but the rotor-type aerator has a poor exchange rate of circulating water between the surface and bottom of the circulation channel, and Since the flow rates of the circulating water at the bottom and the bottom were significantly different (see flow rate line V), stirring of the sludge and sewage, which have 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 channel, the difference in flow velocity between the surface and bottom can be reduced (see flow velocity line V) and the agitation rate of the sludge and sewage. A vertical shaft type surface aerator with improved performance 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, which impairs 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, the central portion j! in the longitudinal direction of the oval aeration tank! I
Water treatment in which activated sludge treatment is carried out by providing a wall to form a circulation waterway, installing a vertical axis type surface aerator adjacent to one end of the central separation wall, and aerating and circulating wastewater within the waterway. In the device, a vertically downward columnar area in the water, including the rotating surface of the blades attached to the lower end of a vertical shaft type surface aerator, is surrounded by a lifting tube, and an opening is opened at the lower end of the lifting tube on the side of the central separation wall. By providing a section, wastewater flowing at the bottom is guided to the surface, and by providing a guide plate in a part of the periphery of the aeration space above the water surface, the wastewater is scattered in a direction that obstructs the flow of the circulation channel during aeration. The system is designed to improve the flow of the circulation waterway by diverting the wastewater in the same direction as the circulation.

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, ■ 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 aeration v&3 has an aeration blade 3a attached to the lower end of a rotating shaft driven by an electric motor installed at the top. 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 4as 4b formed in a part of the lower end of the cylindrical body, and the guide plate 5 is a plate-shaped body formed in a curved plane that is 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 38 of the aerator 3, the water pumping tube 4 is placed so that the upper end surrounds the blade 3a, and the lower end is in contact with the bottom surface of the circulation waterway; In addition, the lower end openings 4a and 4b face the central separation wall 2 side, and the opening 4a
, 4b (
(see Figures 3, 4, and 5), and a part of the periphery of the aeration space of the aerator 3 (inflow side) at a position above the water surface.
Attach the guide plate 5 to (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 due to this scattering, oxygen is 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 wastewater that is scattered by the blade in a direction that obstructs the flow of the circulation channel collides with the guide plate 5, changes its direction in the same direction as the flow of the circulation channel, and falls onto the sewage water surface (see Figure 5). . still,
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 is bypassed and pumped from the openings 4a to 4b formed on the opposite side of the central separation wall. It flows out of the water bottle.

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 in the flow rate of wastewater between the surface and the bottom of the tank 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 present 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 ditch 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 shaft type surface aerator, 3a...Blade, 4 river water pump, 4a
, 4b... opening, 5... guide plate. 51

Claims (1)

[Claims] 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 aerate the wastewater within the waterway. In a water treatment device that processes activated sludge by circulating it,
By surrounding the columnar area vertically below the water, including the rotating surfaces of the blades disposed at the lower end of the surface aerator, with a water pump, and providing an opening at the lower end of the central separation wall of the water pump. The structure is configured to guide 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 circulate wastewater that is scattered in a direction that obstructs the flow of the circulation channel during aeration. A water treatment device characterized in that the water treatment device is configured to improve the flow of a circulation waterway by changing the direction in the same direction.