JPS6216123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning immiscible liquids, and more particularly to an apparatus for cleaning water from oils, fats, and greases.

The invention is particularly advantageous when applied to the purification of backwash water, ballast water or bilge water.

Prevention of marine pollution is one of the most important environmental protection issues.

Discharging wastewater into the sea pollutes the sea, contaminates sea life, and is extremely harmful to the production and capture of marine products.

The limit for the discharge of bilge water into the sea was recognized by the International Conference on the Prevention of Pollution from Ships in 1973.
Less than 100ppm oil. Once the vessel enters the 12 mile zone, this regulation becomes even more stringent and the oil content must be
It will be 15ppm or less. Some countries prohibit the discharge of all oily emissions from ships within their territorial waters.

Therefore, there is an urgent need to install a device onboard a ship that can perform the desired purification.

In order to quickly solve this problem, it is important to have a device that has a simple structure and a purification method that is as simple as possible, as long as it meets the above-mentioned regulatory values. Currently known simple devices for separating liquid mixtures cannot reduce the bilge water below the above-mentioned regulatory value.

That is, the known oil/water separator (GDR Patent No. 78744) consists of a tank with an outlet top for the separated oil, the internal space of which is divided into two parts communicating with each other. The lower part of the first part is provided with an inlet for the oil-water emulsion to be separated, and inside thereof a coarsening filter and a V-shaped duct for oil separation are arranged. The apex of this V-shaped duct faces upward and communicates with the oil outlet. A purified water outlet is provided at the bottom of the second part of the internal space of the tank.

A first portion of the interior space of the tank has a second liquid volume.
The tank is horizontally divided by a cylinder that is smaller than the tank and serves as a partition wall that divides the internal space of the tank.

The V-shaped ducts are vertically spaced from each other, with the duct having the largest dimension or volume at the top.
This uppermost, largest upper V-shaped duct is provided with an opening for draining the oil, the bottom edge of this duct resting on the edge of the cylindrical bulkhead.

A slit for draining purified water is provided between the V-shaped duct and the edge of the cylindrical partition.

This separator has no openings in all of the V-shaped ducts except for the upper V-shaped duct, so a preliminary operation is required to exhaust air from there.In particular, this preliminary operation includes an operation of reversing the separator. Special operations are required.

In addition to these undesirable disadvantages, this separator has several additional operational disadvantages. That is, since the water outlet or slot is at the same level as the interface between the coarse oil and the water, the water exiting the slot flows out together with the separated oil. As a result, water purification efficiency is naturally significantly reduced. Even if this slot is located below the level of the coarse oil, the above-mentioned drawbacks will not be solved since the emulsion will flow directly into the slot without undergoing separation.

Furthermore, in conventional separators, the oil floats on top of the purified water, which can cause the oil and water to mix with each other, and it is extremely undesirable to subject the separator to rolling or vibration. Therefore, such separators are not practical on ships.

The present invention has a simple structure and improves the efficiency of separating water from oil by discharging the oil separated from the oil-water emulsion separately from purified water.
It provides a water separator.

The oil-water separator provided by the present invention is comprised of a tank having a separated oil outlet in the upper part and having an internal space divided into two parts communicating with each other, the first part being in the lower part. It has an inlet for the liquid to be separated, and has inside thereof a coarsening filter and a V-shaped duct for oil separation whose apex faces upward and communicates with the outlet of the oil. The second part has an outlet for the purified water at its lower part, and the feature according to the invention is that the sides of the V-shaped duct are partitioned by the walls of the tank,
A V-shaped duct has a passage extending upward, one side of which is longer than the opposite side, and a plurality of such V-shaped ducts are arranged side by side, each long side forming a flow path, and each vertex is located at a point where the extension line of the apex of the adjacent V-shaped duct extends beyond the intersection point where it intersects the surface by at least 2/3 of its total length.

This separator of the present invention not only improves oil-water separation efficiency but also has a simple structure and a simple separation method.
These advantages of the invention are such that the oil droplets, which are highly buoyant in the water, move upwards and at the same time are carried by the liquid flowing towards said channel of the V-shaped duct, i.e. are directed towards the oil accumulation chamber. This is believed to be achieved by the liquid mixture to be separated flowing along a channel defined by the long sides of the V-shaped duct. In other words, the oil droplet flows along the diagonal of a parallelogram of velocity vectors, one side of which is the flow velocity of the oil-water emulsion, and one side of which is the floating velocity of the oil droplet in water, ie, along the resultant force vector. The water from which the oil has been removed flows away from the oil layer along the long side of the V-shaped duct in a laminar flow state, and a layer is formed between the short side of the V-shaped duct and the long side of the adjacent V-shaped duct. It flows into the slit. The oil carried by this water flow is intercepted and collected by the short sides of the V-shaped duct.

It can therefore be said that because the velocity vectors of the oil and water are different and at an angle to each other, the water is discharged away from the oil accumulation or holding area in the V-shaped duct.

Preferably, the first and second parts of the interior space of the tank are separated from the oil outlet by a partition. That is, it is preferable that the upper part of the internal space of the tank is defined by this partition wall, and that the passage of the V-shaped duct extends into this upper space.

With this structure, it is possible to prevent oil from flowing into the second portion of the tank interior space from which purified water is discharged.

The partition separating the first and second parts of the interior space of the tank from the oil outlet can be a conical enclosure. The apex of this conical enclosure faces upward and has an opening in its center for draining the oil.

This partition serves to further separate the oil droplets flowing in the opposite direction from the water flow towards the drain.

The passageway extending upwardly of the V-shaped duct may be in the form of vertically extending pipes provided at both ends of the apex of the V-shaped duct.

The invention will now be described by way of example with reference to the accompanying drawings.

Referring to FIG. 1, the oil-water separator of the present invention has a tank 1, and an outlet 2 is provided in the upper part of the tank 1 for extracting separated oil.
The interior space of the tank 1 is divided by a vertical line into two mutually communicating parts, a first part 3 and a second part 4. The first part 3 has an inlet 5 for introducing the oil-water emulsion into the separator. A conventional coarsening filter 6 is arranged in the first part 3 of the internal space of the tank 1 . A V-shaped duct 7 is provided above this coarsening filter 6 in the first part 3 and communicates with the oil outlet 2 . The apexes of these V-shaped ducts 8 point upwards (FIG. 2). The second part 4 of the interior space of the tank 1 is provided with an outlet 8 for purified water.

The volume of the first portion 3 of the internal space of the tank 1 is
Preferably, it is larger than the volume of portion 4.

The V-shaped duct 7 is elongated (FIG. 3) and bounded on both sides by walls 9, 10 of the tank 1.

An opening is formed at the apex of the V-shaped tact 7, and a passage 11 (see Figs. 1 and 2) extends upward from this opening.
It's growing. Further, one side 12 of the V-shaped duct 7 is longer than the opposite side 13. A plurality of V-shaped ducts 7 are arranged side by side so that a passage for the emulsion to be separated is formed by the long side. The long sides 12 of the V-shaped duct 7 have a length such that each end 15 thereof extends by at least 2/3 of its total length from the intersection M where the extension line of the apex of the adjacent (front) duct intersects its surface. have.

As can be seen from Figures 1 and 2, each V-shaped duct 7
Preferably, the vertices of are arranged on one and the same horizontal line. Furthermore, the internal space of the tank 1 is divided into a first portion 3.
It is also preferable that the upper end edge of the vertical partition wall 16 dividing into the second portion 4 is also on the same horizontal line as the apex of the V-shaped duct 7.

The operation method of the above oil-water separator will be explained below.
The oil-water mixture to be separated, such as bilge water, is fed to this separator by a bilge pump (not shown). This mixture flows into the first part of the tank 1 via the inlet 5. This emulsion is then pushed upward by the action of a bilge pump (not shown) and sent to the coarsening filter 6.

The oil droplets are coalesced into large oil droplets in the coarsening filter 6. The emulsion that has passed through the coarsening filter 6 becomes a laminar flow and rises to the V-shaped duct 7. The emulsion further flows as a biased flow along the passage 14 due to the inclination angle of the long side 12 of the V-shaped duct 7. While the oil-water emulsion flows along this passage 14, the more buoyant oil droplets rise or move upwards and are simultaneously carried away by the liquid flow towards the outlet of the passage 14. In other words, the oil droplet flows along the resultant force vector R (FIG. 2). As can be seen from FIG. 2, this resultant force vector R is a velocity vector, that is, a diagonal of a parallelogram whose one side is the vector L of the emulsion velocity and the other side is the vector K of the floating velocity of the oil droplet in water. The separated oil is collected at the top of the V-shaped duct and is pushed up by the accumulated flow of oil that flows continuously upward along the passageway 11 and further into a suitable oil recovery tank. In the illustrated embodiment of the present invention, this oil recovery tank is connected to the tank 1 by a horizontally extending partition wall 17 in the internal space of the tank 1.
is formed at the top of the

In another embodiment, the partition wall 17 can be a conical enclosure 17' with an upwardly directed apex. An opening is provided in the upper part of this enclosure 17'.

In operation, purified water flows from the first part to the second part of the interior space of the tank 1. water comes first
Upon exiting part 3, further purification takes place. That is, unseparated oil droplets float to the surface and are collected under the conical partition wall 17'.

The collected oil flows into the upper part of the oil recovery tank or tank 1 through the opening in the conical partition wall 17'. Oil is discharged from the top of this tank 1 via an outlet 2. The purified water coming from the first part 3 of the interior space of the tank 1 is discharged through the outlet 8.

As can be seen from Figure 3, passage 1 of the V-shaped duct
1 is formed by at least two pipes 11' placed close to said side wall of the V-shaped duct. The number of pipes 11' depends on the throughput of the separator.

Example Oil containing 50,000 to 100,000 ppm of oil - The above oil of the present invention with a throughput of water emulsion of 3 m ³ /hr -
It was supplied for separation treatment in a water separator. The separated water was less than 100 ppm.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the oil-water separator of the present invention. Second
The figure is a detailed enlarged view of Figure 1 showing the V-shaped duct and the velocity vectors of oil and water. FIG. 3 is a view taken from the side wall of the separator in the direction of arrow A in FIG. 1 to show the shape of the V-shaped duct. Symbols in the figure: 1: Tank, 2: Oil outlet, 3: First part of tank internal space, 4: Second part of tank internal space, 5: Inlet of oil-water emulsion, 6: Coarsening filter, 7 :V-shaped duct, 8:Water outlet,
9, 10: tank wall, 11: passage, 11': pipe, 12: long side of V-shaped duct, 13: short side of V-shaped duct, 14: passage, 15: end of long side of V-shaped duct, 16 : Vertical partition wall, 17: Partition wall.

Claims (1)

[Scope of Claims] 1. An oil separation V having an inlet for the liquid to be separated at the lower part and having a coarsening filter 6 inside and the top facing upward and communicating with the outlet for the separated oil. a first part 3 with a shaped duct 7 and a second part 4 with an outlet 8 for purified water in the lower part
In an oil-water separator constituted by a tank 1 having an internal space divided into two mutually communicating parts and having an outlet 2 for the separated oil in the upper part, said V-shaped duct The sides of the V-shaped duct 7 are partitioned by the walls 9 and 10 of the tank, and the V-shaped duct 7 has a passage 11 extending upward, and one side 12 thereof is longer than the other side 13.
A plurality of V-shaped ducts are arranged side by side, and their long sides 12 define a flow path 14, and each long side is connected to the adjacent V-shaped duct.
An oil-water separator characterized in that the oil-water separator extends beyond the intersection point M where the extension of the apex of the shaped duct 7 intersects with its surface by at least 2/3 of its total length. 2 First part 3 and second part 4 of the internal space of the tank
are horizontally separated from the oil outlet 2 by a partition 17, and the passage of the V-shaped duct 7 is separated from the oil outlet 2 by a partition 17.
7. A separator according to claim 1, wherein the separator extends through the separator 7. 3. The separator according to claim 2, wherein the partition wall 17 is a conical enclosure 17' whose apex extends upward and has an opening at the center. 4. Separator according to claim 1 or 2, characterized in that the channels of the V-shaped duct are formed as at least two pipes 11'.