JPS6354414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mixing device, and particularly to a mixing device that can effectively stir and mix a mixture containing components of two or more phases in sewage treatment or chemical treatment.

Dispersion or agitation mixing of two or more phases of liquid or gas and liquid is required in various treatment processes, such as sewage treatment processes in which oxygen is supplied to wastewater, waste liquid, etc. to activate the wastewater,
It is also well known as a liquid of two or more phases or a mixture of a gas and a liquid during emulsification, reaction, or dissolution in chemical processing.

Conventionally, the above-mentioned agitation mixing has generally been carried out using a pump or a static mixer, but even with these mixing devices, unmixed materials are produced, which significantly reduces the mixing efficiency. Furthermore, if the amount of unmixed gas or liquid components exceeds a predetermined amount, there is a problem that an explosion or other danger may occur.

The present invention has been made in view of the above-mentioned conventional problems, and the object thereof is to improve the mixing efficiency by subjecting the unmixed components to the mixing action again, and to provide an improved method capable of performing an effective mixing action. The object of the present invention is to provide a mixing device that has the following characteristics.

In order to achieve the above object, the present invention provides a closed retention container into which a mixture containing components of two or more phases is introduced and retains these components as at least an upper phase and a lower phase; an inlet pipe for guiding the mixture into the retention container, the inlet pipe having a suction opening provided on the side thereof and opening into the upper phase, and a suction opening provided near the suction opening so that the mixture is directed downwardly. a cylinder body that surrounds the injection nozzle, extends into the lower phase, and opens downward, and the mixture is injected from the injection nozzle into the retention vessel. The components of the unmixed upper phase remaining in the upper part are sucked into the inlet pipe through the suction opening and subjected to remixing, and the recombined mixture is introduced into the lower phase, thereby causing the mixture to flow into the lower phase. It is characterized by being diffused downward at.

Preferred embodiments of the present invention will be described below based on the drawings.

Figure 1 shows a mixing device used in a sewage treatment system that activates sewage by injecting oxygen into returned sludge returned from a settling tank to a dusting tank in urban sewage and other wastewater treatment processes. Return sludge from a settling tank (not shown) is returned to the dusting tank via return conduits 10 and 12, and both return conduits 10 and 1
A closed retention container 14 according to the present invention is provided between the two. The retention container 14 is returned to the return conduits 10, 12.
The inlet pipe 1 has an airtight structure except for the inlet and outlet parts connected to the inlet pipe 1 provided at the upper part in the embodiment.
From 6 onwards, a mixture containing components of two or more phases is introduced. The mixture in the embodiment includes return sludge supplied from a return conduit 10 and a valve 1 in the return conduit 10.
The sludge is composed of liquid and gas components with oxygen supplied from 8, and the oxygen is mixed into the returned sludge, and the bacteria in the returned sludge are sufficiently activated to perform sewage treatment. The retention container 14 according to the present invention can ensure sufficient processing time for the return sludge and oxygen, that is, the flow passage cross-sectional area of the retention container 14 is sufficiently large compared to the area of the return conduits 10 and 12. Since the activated sludge and oxygen supplied from the return conduit 10 remain in the retention container 14 for a sufficiently long time, the oxygen is sufficiently dissolved in the return sludge within this retention time, and bacteria are removed. will be effectively activated.

In the embodiment shown in FIG. 1, the introduction pipe 16 has a substantially cylindrical shape, and its upper opening is connected to the return pipe 10 to introduce the mixture of return sludge and oxygen, and its lower end opening is connected to the return pipe 10. It extends into the mixture that stays inside. and,
The lower end is open downward. The inlet pipe 16 in the embodiment is a substantially straight cylindrical body, through which oxygen is dissolved as the returned sludge passes at a relatively high speed.

Further, in the present invention, a suction opening 20 is provided on the side of the introduction pipe 16, and the suction opening 20 is provided at the side of the introduction pipe 16.
It is characterized in that an injection nozzle 22 consisting of an orifice is formed in the vicinity of the injection nozzle 22. As a result, the return sludge introduced into the introduction pipe 16 and oxygen are sufficiently stirred and mixed during injection by the injection nozzle 22,
It is characterized in that the unmixed oxygen remaining in the upper part of the retention container 14 is sucked into the introduction pipe 16 through the suction opening 20 and subjected to remixing. That is, when the return sludge and oxygen are mixed in the closed retention container 14, unmixed oxygen that cannot be dissolved in the return sludge rises to the liquid surface of the return sludge and accumulates in the upper part of the retention container 14. As described above, the introduction pipe 16 of the present invention is provided with a suction opening 20 on the side thereof, and has an injection nozzle 2 in the vicinity of the suction opening 20.
2, when the return sludge flows through the introduction pipe 16 at high speed, the oxygen accumulated near the suction opening 20 is drawn into the introduction pipe 16,
It is sufficiently stirred and mixed with the returned sludge again, making it possible to sufficiently dissolve it into the sludge.

As described above, according to the embodiment shown in FIG.
Oxygen is efficiently stirred and mixed into the returned sludge in the closed retention container 14, and unmixed oxygen is not discarded as it is but is repeatedly contacted and mixed with the returned sludge, so that the returned sludge can be activated extremely efficiently. becomes possible. Further, since the mixture is discharged downward from the lower end of the introduction pipe 16, the residence time in the bubbles becomes longer, and mixing and dissolution is promoted.

A second embodiment of the invention is shown in FIG.
Since the configuration is substantially the same as that shown in the drawings, the same members are given the same reference numerals and explanations will be omitted.

A characteristic feature of the embodiment shown in FIG. 2 is that a static mixer 24 is provided below the introduction pipe 16, and the return sludge and oxygen are transferred
4, the mixture is sufficiently mixed and stirred, making it possible to further improve the mixing efficiency.

In each of the above-mentioned embodiments, oxygen is used to activate the returned sludge, but this oxygen may be pure oxygen or air, or other activating agents such as a mixed gas of pure oxygen and ozone may be used as appropriate. , hydrogen peroxide, sodium hypochlorite, or a mixture of pure oxygen and a flocculant.

Furthermore, although a mixture of returned sludge and oxygen is used in the examples, the apparatus of the present invention can also be used for reactions, dissolution, or emulsification of two-phase liquids or liquids and gases in chemical treatment processes. This is possible, and is extremely effective especially when emulsifying oil and water, which have different specific gravity, such that components with lower specific gravity float to the top of the retention container 14 as unmixed components, and are sucked into the introduction pipe again. The mixture will then be remixed.

As described above, according to the present invention, a mixture containing components of two or more phases can be mixed extremely efficiently, and the apparatus can be downsized.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a preferred embodiment of a mixing device according to the present invention, and FIG. 2 is a schematic diagram showing another embodiment of the present invention. 14...closed retention container, 16...introduction pipe, 2
0... Suction opening, 22... Injection nozzle.

Claims (1)

[Scope of Claims] 1. A closed retention container into which a mixture containing components of two or more phases is introduced and retains these components as at least an upper phase and a lower phase; and a closed retention container provided within the retention container to retain the mixture. an inlet pipe for introducing the mixture into the container, the inlet pipe having a suction opening provided on the side thereof and opening into the upper phase, and a suction opening provided near the suction opening through which the mixture is injected downward. an injection nozzle that surrounds the injection nozzle, extends into the lower phase, and opens downward; The components of the mixed upper phase are sucked into the inlet pipe through the suction opening and subjected to remixing, and the recombined mixture is introduced into the lower phase to direct the mixture downward in the lower phase. A mixing device characterized by diffusion.