JPH05212210A - Oil-water separator - Google Patents

Abstract

PURPOSE:To accelerate the separation of oil content from water and to make easy the discharge of separated liquid by giving raw water agitation, mixing and shearing to make a circulating flow centering an aerator and installing liquid level instruments in an oil-water separating tank and a floating sludge receiving hopper. CONSTITUTION:Air is fed to an aerator 8 while raw water is forcibly fed to the bottom part of the aerator 8 from a raw water inflow pipe 11, and the raw water mixed and rising is further given agitation, mixing and shearing to raise it by a baffle plate 8b. In a floating sludge receiving hopper 4, when an electrode (b) of a liquid level instrument 7A for detecting the upper limit of the floating sludge is operated, a discharge pump P runs. In an oil-water separation tank 1, an electrode (a) of a liquid level instrument 7B detects oil content and the electrode (b) detects water. Thereby oil-water separation and the removal of floating sludge are made easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-water separator for separating oil-containing wastewater from oil-water while concentrating the oil and water. In particular, food manufacturing wastewater and other wastewater containing oil are activated as they are. When biological treatment such as the sludge method is performed, activated sludge is likely to float or the load on the aeration tank increases, and its treatment performance often deteriorates.Before such biological treatment of wastewater, The present invention relates to an oil / water separator as a pretreatment facility for removing oil and SS (solid suspended matter of 2 mm or less).

[0002]

2. Description of the Related Art Originally, when oil and water in drainage (raw water) are left to stand for a long time, the oil naturally collects in the upper layer, but that requires a long residence time. However, it requires a large space. Even now, there is a static oil separation facility called a grease trap, but there were problems such as a putrid odor due to a long residence time and the need for manpower to remove the floating oil. There are also automated ones, but the equipment is complicated and expensive because of that, and there is a problem in terms of price at a small scale.

[0003]

There is no doubt that environmental problems will become more severe in the future, and even small-scale wastewater factories that are not currently subject to wastewater regulations are likely to become the target in the near future. In that case, if it is too expensive, it may put pressure on management, so it is desirable to develop a product that has the desired function at a low price.

Therefore, according to the present invention, the oil and water are separated in the circulation of the raw water by forming a circulation flow in the oil-water separation tank by the supply pressure of the raw water and the air pressure of the air. The present invention provides an efficient oil-water separator having a small structure and a simple structure that does not require human labor by easily discharging the oil.

[0005]

In order to achieve the above object, the invention according to the first aspect is characterized in that a funnel-shaped straightening plate 3 having a through hole at the center is fixed to the bottom of an oil / water separation tank, and An inverted conical floating sludge receiving hopper 4 is fixed to the upper center of the separation tank 1, and a cylindrical aerator is provided in the center of the oil / water separating tank between the flow straightening plate 3 and the floating sludge receiving hopper 4. 8 is arranged, and the aerator 8 has an air supply pipe.
10 is connected and the discharge port of the raw water inflow pipe 11 is made to face the bottom of the aerator 8, and the floating sludge receiving hopper 4 is connected.
Further, liquid level gauges 7A and 7B are attached to the oil / water separation tank 1, respectively, and a discharge pipe 6 is exposed to the bottom of the floating sludge receiving hopper 4, so that a space between the bottom of the oil / water separation tank 1 and the straightening plate 3 is provided. The treated water discharge pipe 12 is connected to the side wall of the oil-water separation tank 1, and one of the liquid level gauges 7A attached to the floating sludge receiving hopper 4 indicates the water level of the floating sludge of the floating sludge receiving hopper 4. Of the liquid level gauge 7B attached to the oil / water separation tank 1 is connected so as to drive or stop the discharge pump P provided in the floating sludge discharge pipe 6 by detecting the upper and lower limits of the liquid level gauge 7B. Is characterized in that when the oil content is detected, the valve V ₁ of the treated water discharge pipe 12 is closed, and when the water content is detected, the valve V ₁ is opened.

The invention according to the second aspect is characterized in that the aerator 8 is composed of an air lift pipe 8a having a baffle inside and a cylindrical aerator body 8d having a plurality of air discharge holes on its inner wall. Is.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 is an oil-water separation tank having an inverted cone-shaped bottom portion 1A and an open top portion. The bottom portion 1A is provided with a settling sludge discharge pipe 2 for discharging settled settled sludge at the bottom. It is connected.

A current plate 3 is fixed inside the oil / water separation tank 1 and near the bottom 1A. The current plate 3 has a funnel shape having a through hole 3A in the center.

A treated water discharge pipe 12 for discharging treated water is attached to the side wall of the oil / water separation tank 1 between the bottom portion 1A and the rectifying plate 3.

In the center near the upper opening of the oil-water separation tank 1,
A floating sludge receiving hopper 4 which is a small-diameter inverted conical dish is supported by supporting members 5 and 5. Hopper 4
The leading end of the levitation sludge discharge pipe 6 faces the bottom of the above.

Further, a liquid level meter 7A for measuring the liquid level in the hopper 4 is attached by an appropriate means, and a liquid level meter 7B for measuring the liquid level in the oil / water separation tank 1 is also provided.
Are attached by appropriate means.

The liquid level meter 7A is provided with electrodes a and b for detecting the upper and lower limits of the floating sludge, and the liquid level meter 7B is
An electrode a for detecting oil and an electrode b for detecting water are provided.

As will be described later, the liquid level meter 7A controls the floating sludge discharge pump P, and the liquid level meter 7B controls the blower 10A of the air supply pipe 10 and the valve V ₁ of the treated water discharge pipe 12. Is provided.

An aerator 8 is provided so as to be located in the center of the oil / water separation tank 1 between the flow regulating plate 3 and the hopper 4.
It is supported by an appropriate suspending member 9 from the supporting members 5 and 5.

The aerator 8 is, as shown in FIG.
An air lift pipe 8a having an opening whose diameter is expanded upward, and a baffle plate having a through hole arranged in the middle of the air lift pipe 8a.
8b and an aerator body of a hollow cylindrical body connected to the lower part of the air lift pipe 8a and having a plurality of air discharge holes 8c on the inner wall.
8d and an air supply pipe 10 for supplying air to the inside of the aerator body 8d.

A discharge port of a raw water inflow pipe 11 for supplying raw water from the bottom side of the aerator body 8d toward the inside of the cylinder is exposed.

Next, the operation of this device will be described with reference to FIG. First, while supplying air to the aerator 8 via the air supply pipe 10, the raw water to be treated is pressure-fed to the bottom of the aerator 8 from the raw water inflow pipe 11. As a result, the raw water is mixed with air and rises, but the baffle plate 8b
Is further stirred, mixed, and sheared to rise.

The ascended raw water hits the conical surface of the lower surface of the floating sludge receiving hopper 4 arranged above the aerator 8, and the raw water slowly moves in the circumferential direction of the oil / water separation tank 1 due to the rectifying effect. Then, it moves downward along the peripheral wall of the oil / water separation tank 1 and is guided below the aerator 8 by the straightening vane 3.

At the same time as the supply of raw water, the same amount of water as the inflow amount of raw water is continuously discharged from the treated water discharge pipe 12, so that the overflow liquid level is always kept constant.

When the above steps are continuously carried out for a while, light substances, that is, oil components, gather in the upper surface layer, and substances heavier than water gather in the lowermost part of the oil / water separation tank 1 due to the circulating flow.

Moreover, since the oil content floating on the upper surface is viscous, the sheared oil content moving in the upper and lower circulation flows is adsorbed, and the oil layer on the upper surface gradually thickens.

The liquid level meter 7B is an electrode for detecting oil, and when the oil is collected up to this electrode, the blower B of the air supply pipe 10 is stopped and the valve V ₁ of the treated water discharge pipe 12 is closed. Are electrically linked together. Since the raw water is flowing in as it is, the liquid level of the oil-water separation tank 1 rises and becomes equal to or higher than the overflow liquid level, and the raw water overflows to the floating sludge receiving hopper 4.

Further, b of the liquid level meter 7B is an electrode for detecting water, and when the oil layer is discharged and water reaches this point, the blower B is operated to open the valve V ₁ , and the liquid level is the overflow liquid level again. Therefore, the oil does not overflow into the receiving hopper.

In the floating sludge receiving hopper 4, b of the liquid level gauge 7A is an electrode for detecting the upper limit of the floating sludge, and when this works, the discharge pump P interposed in the floating sludge discharge pipe 6 electrically connected. Is operated, the accumulated sludge is discharged, and a of the liquid level gauge 7A is an electrode for detecting the lower limit of the floating sludge, and when this works, the discharge pump P is stopped.

If necessary, the heavy sediment accumulated at the bottom of the oil / water separation tank is discharged by opening the valve V ₂ of the sedimentation sludge discharge pipe.

[0026]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned structure, the raw water and air are supplied to stir and mix the raw water.
By performing shearing and creating a circulating flow centered on the aerator, it is easy to separate oil water, and by installing a liquid level meter in the oil water separation tank and the floating sludge receiving hopper respectively, floating sludge can be easily removed. There is an effect such that heavy precipitates can be collected and removed at the bottom of the oil / water separation tank during circulation of the raw water.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a device of the present invention.

FIG. 2 is a vertical sectional side view of the device of the present invention.

FIG. 3 is an enlarged vertical side view of the vicinity of the aerator of the present invention.

[Explanation of symbols]

1 Oil / water separation tank 3 Rectifier plate 4 Levitating sludge receiving hopper 6 Discharge pipe 7A, 7B Liquid level gauge P Discharge pump V ₁ valve

Claims (2)

[Claims] 1. A funnel-shaped straightening plate having a through hole in the center is fixed near the bottom of the oil-water separation tank, and an inverted conical floating sludge receiving hopper is fixed in the upper center of the oil-water separation tank. A cylindrical aerator is arranged in the center of the oil / water separation tank between the flow straightening plate and the floating sludge receiving hopper, and an air supply pipe is connected to the aerator and the raw water inflow pipe is discharged to the bottom of the aerator. Face the outlet, attach liquid level gauges to the floating sludge receiving hopper and the oil-water separation tank, respectively, and let the discharge pipe face the bottom of the floating sludge receiving hopper, and the bottom of the oil-water separation tank and the straightening plate. The treated water discharge pipe is connected to the side wall of the oil / water separation tank between the two, and one of the liquid level meters attached to the floating sludge receiving hopper is the water level of the floating sludge of the floating sludge receiving hopper. It is linked so as to drive or stop the discharge pump installed in the floating sludge discharge pipe by detecting the upper and lower limits of the above, and the other liquid level gauge attached to the oil / water separation tank detects the oil content. The oil-water separation device is characterized in that when the detection is made, the valve of the treated water discharge pipe is closed, and when the water is detected, the valve is opened. 2. An oil / water separator, wherein the aerator comprises an air lift pipe having a baffle inside and a cylindrical aerator body having a plurality of air discharge holes on its inner wall.