Patent Description:
As countermeasures against oil spill accidents, the spilt oil has forcibly been recovered or an oil treatment agent has been distributed over the water surface to decompose the oil while measures being taken to prevent the oil floating on the water surface from spreading out.

As measures of preventing the oil from spreading out, a float-type water pollution prevention boom has widely been known, and the spread of oil has been regulated by said boom extended on the water (Patent Document <NUM>).

Further, a method of jetting high-velocity water from a ship toward the water surface in a curtain shape to prevent the spread of oil has also been proposed.

As a method of recovering the oil floating on the water surface, navigating an oil recovery vessel equipped with an oil recovery facility to recover the oil has been known.

For such an oil recovery vessel, applying a method of directly skimming the oil floating on the water surface (Patent Documents <NUM>, <NUM>) and applying a method of recovering the oil through the oil recovery facility mounted on said vessel have been known (Patent Documents <NUM>, <NUM>).

The oil recovery facility equipped with a water absorption pump or an evacuation device, an oil-water separation device, and the like has supplied a mixed fluid recovered in a state having water and oil mixed with each other to the oil-water separation device, and the oil-water separation device has separated to recover only the oil.

The conventional oil spread prevention techniques had the following problems:.

The conventional oil recovery techniques had the following problems:.

Conventionally, it has been technically difficult to recover highly viscous oil such as heavy oil of class C, and it has been desired to propose a new technique enabling highly viscous oil to be recovered.

The conventional method of treating oil through the use of an oil treatment agent had the following problems:.

The present invention is made in view of the above-described problems, and the objective thereof is to provide at least one of the following aspects of a floating-oil recovery device:.

Preferred embodiments of the invention are defined by the dependent claims.

One aspect of the present disclosure provides a floating-oil recovery device comprising: a bubble-curtain generation mechanism configured to discharge air into water to generate a bubble curtain in the water so as to increase a thickness of a film of floating oil while regulating spread of the floating oil; and an ejector configured to recover an oil-water mixed fluid having the floating oil and the water mixed with each other by jetting high-velocity water toward the film of floating oil enclosed with the bubble curtain to destroy the film of floating oil.

Another aspect of the present disclosure may provide a floating-oil recovery device comprising: a bubble-curtain generation mechanism configured to discharge air into water to generate a bubble curtain in the water so as to increase a thickness of a film of floating oil while regulating spread of the floating oil; an ejector configured to recover an oil-water mixed fluid having the floating oil and the water mixed with each other by jetting high-velocity water toward the film of floating oil enclosed with the bubble curtain to destroy the film of floating oil; and an oil-water separation tank that oil is therein separated to be recovered from the oil-water mixed fluid recovered by the ejector.

Still another aspect of the present disclosure may provide a floating-oil recovery device comprising: a support frame to be attached to a portion of a ship; a bubble-curtain generation mechanism configured to discharge air from a bottom portion of the support frame into water to generate a bubble curtain in the water so as to regulate spread of floating oil; an ejector including a nozzle for jetting high-velocity water toward the film of floating oil enclosed with the bubble curtain to destroy the film of floating oil, and an intake pipe for taking in the high-velocity water jetted through the nozzle so as to generate negative-pressure suction force, thereby to recover an oil-water mixed fluid having the floating oil and the water mixed with each other into the intake pipe; and an oil-water separation tank, to be mounted on the ship, that oil is therein separated to be recovered from the oil-water mixed fluid recovered by the ejector, wherein an oil-water recovery pipe is connected between the ejector and the oil-water separation tank, and wherein a water supply pipe provided with a high-velocity water supply unit is connected between the oil-water separation tank and the nozzle so that the water separated in the oil-water separation tank is circulated to be supplied to the nozzle as the high-velocity water through the water supply pipe and the high-velocity water supply unit.

As other aspects of the present disclosure, the floating-oil recovery device of said still another aspect of the present disclosure may be provided, wherein a portion of the ejector having a float attached thereto is supported pivotably on a portion of the support frame so as to be swingable in a vertical direction in such a manner that a height of oil and water taken in by the ejector follows a change in water level.

As other aspects of the present disclosure, the floating-oil recovery device of said one aspect, said another aspect, or said still another aspect of the present disclosure may be provided, wherein the bubble-curtain generation mechanism includes: an aeration pipe arranged on a support frame to be attached to a portion of a ship; an air supply unit having an air pump and a motor mounted on the ship; and an air supply pipe connected between the aeration pipe and the air supply unit, and wherein the bubble curtain is generated by an ascending flow of a group of bubbles discharged from the aeration pipe.

As other aspects of the present disclosure, the floating-oil recovery device of said still another aspect of the present disclosure may be provided, wherein the oil-water separation tank includes: a main tank that the oil-water mixed fluid recovered by the ejector is stored therein; and a plurality of partition plates arranged in the main tank, wherein oil and water are separated with the aid of difference in specific gravity in the main tank.

As other aspects of the present disclosure, the floating-oil recovery device of said still another aspect of the present disclosure may be provided as further comprising: an auxiliary tank, mounted on the ship, that an oil treatment agent is stored therein; an oil treatment agent supply unit configured to supply the oil treatment agent stored in the auxiliary tank to the water supply pipe; and an auxiliary pipe connected between the oil treatment agent supply unit and the water supply pipe, wherein the film of floating oil and the oil treatment agent floating on a water surface are stirred to be mixed through the use of the ejector having the intake pipe arranged such that an outlet side of the intake pipe faces into the water.

The present invention can achieve at least one of the following advantageous effects:.

Hereinafter, a floating-oil recovery device in an embodiment according to the present invention will be described in detail with reference to the drawings.

Embodiments will be described with reference to <FIG>, <FIG>. In this example, an embodiment applied to the floating oil spilled out over the sea surface will be described, and such an embodiment may also be applied to the floating oil spilled out over the water surface such as those of rivers and lakes.

A floating-oil recovery device <NUM> in an embodiment according to the present invention is a device capable of improving the efficiency of recovering floating oil while suppressing the spread of floating oil in a non-contact manner.

The recovery device <NUM> includes: a support frame <NUM> attached integrally to a portion of a ship <NUM>; a bubble-curtain generation mechanism configured to discharge air from a bottom portion of the support frame <NUM> into water to generate a bubble curtain in the water so as to regulate the spread of floating oil; and an oil-water recovery mechanism configured to recover the floating oil whose spread is regulated by the bubble curtain.

In this example, an embodiment using the recovery device <NUM> mounted on the ship <NUM> such as a catamaran will be described. The ship <NUM> is not, however, limited to the catamaran, and may include a single-hulled vessel and towing vessel. Further, a position at which the ship <NUM> is attached with the recovery device <NUM> may be the front, side, or rear position of the ship <NUM>.

Hereinafter, the main elements will be described in detail.

In the descriptions of the support frame <NUM>, an "A" side of an intake direction of floating oil is defined as a "front side," and an opposite side to the "A" side of the intake direction of floating oil is defined as a "rear side.

With reference to <FIG>, <FIG>, the support frame <NUM> is a rigid frame body to be arranged thereon with: an aeration pipe <NUM> for discharging air into water; and an ejector <NUM> for destroying to recover a film of floating oil through the use of a high-velocity water jet flow. The support frame <NUM> in a substantially rectangular parallelepiped shape is obtained as a result of assembling rigid members such as single pipes arranged vertically and horizontally.

The support frame <NUM> has at least: a bottom frame portion <NUM> to be arranged thereon with the aeration pipe <NUM> in a flat C-shape or in a flat U-shape; and a front-side horizontal support shaft <NUM> for supporting the ejector <NUM> pivotably on a front-side upper portion of the support frame <NUM>.

The attachment height of the support frame <NUM> with respect to the ship <NUM> is adjustable.

In an embodiment according to the present invention, a known oil boom is no longer used as floating-oil containment means.

In an embodiment according to the present invention, the spread of floating oil is regulated through the use of a bubble-curtain generation mechanism.

With reference to <FIG>, <FIG>, the bubble-curtain generation mechanism includes: the aeration pipe <NUM> arranged on the bottom frame portion <NUM> of the support frame <NUM>; an air supply unit <NUM> having an air pump and a motor mounted on the ship <NUM>; and an air supply pipe <NUM> connected between the aeration pipe <NUM> and the air supply unit <NUM>.

The aeration pipe <NUM> is a pipe or tube having both ends closed and a peripheral surface perforated with a plurality of aeration holes 30a along a longitudinal direction of the pipe or tube between both the ends.

As a result of continuously or intermittently supplying air through the air supply unit <NUM> and the air supply pipe <NUM>, a flat C-shaped or flat U-shaped bubble curtain can be generated in the water immediately above the aeration pipe <NUM>.

In this example, an embodiment having the aeration pipe <NUM> arranged on three sides, other than the front side, of the bottom frame portion <NUM> of the support frame <NUM> will be described. The number of aeration pipes <NUM> arranged on each side is appropriately selected.

The reason why the aeration pipe <NUM> is not arranged on the front side of the support frame <NUM>, i.e., the "A" side of the intake direction for the floating oil, is to take in the floating oil through the front side into a region surrounded by the bubble curtain generated above along the three sides of the bottom frame portion <NUM> of the support frame <NUM>. The reason why the aeration pipe <NUM> is arranged on the three sides of the bottom frame portion <NUM> of the support frame <NUM> is to confine the taken-in floating oil inside the region surrounded by the bubble curtain so as to prevent the floating oil from flowing outside the surrounded region.

In other words, the bubble curtain not only performs the function of preventing the spread of floating oil "O," but also performs the function of confining the floating oil inside the bubble curtain so as to increase the thickness of the film of floating oil "O" (a floating oil film thickening function).

The oil-water recovery mechanism is a mechanism configured to enable the floating oil to be pipe-transported in the form of oil-water mixed fluid obtained as a result of destroying the film of floating oil through the use of a high-velocity water jet flow.

With reference to <FIG>, <FIG>, the oil-water recovery mechanism includes: an ejector <NUM> supported by the support frame <NUM> in a pivotable and rotatable manner around the front-side horizontal support shaft <NUM> of the support frame <NUM>; an oil-water separation tank <NUM> mounted on the ship <NUM>; a high-velocity water supply unit <NUM> having a water supply pump and a motor; a water supply pipe <NUM> connected between the ejector <NUM> and the high-velocity water supply unit <NUM>; and an oil-water recovery pipe <NUM> connected between the ejector <NUM> and the oil-water separation tank <NUM>.

The ejector <NUM> shown in <FIG> will be described. The ejector <NUM> includes: a nozzle <NUM> for jetting high-velocity water; an intake pipe <NUM> positioned at a jetting side of the nozzle <NUM>; and a float <NUM> for adjusting automatically a height of oil and water taken in by the ejector <NUM> such that the height follows a change in local water level.

The ejector <NUM> is not limited to an embodiment shown in <FIG>, and any devices capable of sucking a mixed fluid of floating oil and water by an ejector function (Venturi effect) may be applied.

In this example, an embodiment having one ejector <NUM> deployed for one support frame <NUM> will be described; and alternatively, a plurality of ejectors <NUM> may be deployed for one support frame <NUM>.

A water supply pipe <NUM> bent in a J-shape has an inlet side connected to an outlet tip of the water supply pipe <NUM>, and the nozzle <NUM> is provided at an outlet tip of the water supply pipe <NUM>. High-velocity water can be continuously jetted through the nozzle <NUM> toward an inlet port of the intake pipe <NUM>.

The intake pipe <NUM> is provided at an inlet tip of the oil-water recovery pipe <NUM>.

High-velocity water jetted from the nozzle <NUM> can be taken in, by the intake pipe <NUM>, through the opening (inlet port) at the end of the intake pipe <NUM>.

As a result of the occurrence of the ejector function (Venturi effect) induced by jetting high-velocity water into the intake pipe <NUM>, the mixed fluid of floating oil and water located around a region of the opening (inlet port) at the end of the intake pipe <NUM> can be sucked into the intake pipe <NUM>.

A coupling plate <NUM> is a member for coupling integrally the water supply pipe <NUM>, the intake pipe <NUM>, and a coupling lever <NUM> of the float <NUM> arranged in parallel with each other.

By such a member, the nozzle <NUM> and the opening of the intake pipe <NUM> are mutually arranged at a predetermined position.

In this example, an open-type ejector, having the intake pipe <NUM> arranged so as to have a predetermined gap G from a jetting side of the nozzle <NUM> such that the oil and water around the jet flow are taken into the intake pipe <NUM> through the predetermined gap G, will be described. The ejector may be a closed-type ejector capable of jetting high-velocity water through the nozzle <NUM> inserted structurally into an end of the intake pipe <NUM> such that the oil and water around the jet flow in the vicinity of the end are taken into the intake pipe <NUM>.

In the open-type ejector, oil can be taken in optimally by adjusting the gap G in accordance with the viscosity or the like of the floating oil.

As shown in <FIG>, <FIG>, the ejector <NUM> is supported by the support frame <NUM> so as to be pivotable as well as movable up and down with respect to the front-side horizontal support shaft <NUM> of the support frame <NUM>.

In this example, an embodiment, having a pivot plate 43a interposed between the front-side horizontal support shaft <NUM> and the intake pipe <NUM>, and a plurality of U-bolts 43c and U-bolts 43b fixed to the pivot plate 43a for retaining the front-side horizontal support shaft <NUM> and the intake pipe <NUM>, respectively, so as to support the ejector <NUM> pivotably, is shown. A known pivotal support structure may be applied.

The ejector <NUM> is provided with the float <NUM>, and as a result, the height of oil and water taken in by the ejector <NUM> can be automatically adjusted so as to follow a change in water level.

In this example, an embodiment attached with the float <NUM> through the coupling lever <NUM> is shown. Alternatively, the float <NUM> may be attached to a portion of the water supply pipe <NUM> or the intake pipe <NUM>, which is associated with the omission of the coupling lever <NUM>.

With reference to <FIG>, the oil-water separation tank <NUM> has a mechanism configured to separate the mixed fluid of floating oil and water recovered by the ejector <NUM> into the floating oil and the water.

In this example, a method of separating floating oil and water with the aid of difference in specific gravity will be described; and alternatively, a known separation method such as a cyclone method can be applied to the oil-water separation tank <NUM>.

An embodiment in this example will be described. The oil-water separation tank <NUM> has a main tank <NUM> and a plurality of partition plates <NUM> arranged vertically at intervals in the main tank <NUM>.

The terminal end of the oil-water recovery pipe <NUM> is connected to the vicinity of the bottom portion of the main tank <NUM> so that the sucked oil-water mixed fluid is discharged into the main tank <NUM>.

The suction pipe <NUM> is connected between the vicinity of the bottom portion of the main tank <NUM> and a suction side of the high-velocity water supply unit <NUM> so that the water separated in the main tank <NUM> can be circulated to be used through the suction pipe <NUM>, the water supply pipe <NUM>, the water supply pipe <NUM>, and the nozzle <NUM>.

An oil recovery tank <NUM> is provided next to the main tank <NUM> so as to allow the main tank <NUM> to overflow with the separated oil and recover the separated oil in the oil recovery tank <NUM>.

In <FIG>, V<NUM> denotes a switching valve interposed between the suction pipe <NUM> and the water supply pipe <NUM>, V<NUM> denotes an on-off valve provided in the oil-water recovery pipe <NUM>, and V<NUM> denotes a drain valve provided in a portion of the oil-water separation tank <NUM>.

A method of recovering floating oil through the use of the floating-oil recovery device <NUM> will be described.

In an embodiment according to the present invention, a taken-in floating-oil spread prevention step by the bubble-curtain generation mechanism, an oil-water recovery step by the ejector <NUM>, and an oil-water separation step by the oil-water separation tank <NUM> are proceeded with in parallel.

In an embodiment according to the present invention, the bubble-curtain generation mechanism is used as means for preventing the spread of floating oil without using a known oil boom.

A method for containment of the floating oil "O" will be described with reference to <FIG>.

The air supply unit <NUM> shown in <FIG>, <FIG> is operated to supply gas such as air through the air supply pipe <NUM> toward the aeration pipe <NUM> arranged in a flat C-shape or in a flat U-shape.

When air or the like is supplied to the aeration pipe <NUM>, as shown in <FIG>, <FIG>, a group of bubbles <NUM> is discharged into the water through the aeration holes 30a of the aeration pipe <NUM>, and the surrounding water entrained with the floating group of bubbles <NUM> forms an ascending water flow <NUM> in a curtain shape.

A bubble curtain is generated by the ascending water flow <NUM> isolated from the surrounding sea area and the group of bubbles <NUM> floating on the water surface.

The floating oil "O" is taken in inside an area surrounded by the bubble curtain through an open space of the bubble curtain.

The bubble curtain is generated in a curtain shape continuous over a below-water section from a depth not less than a film-thickness of floating oil "O" to the water surface as well as an above-water section as an upper part of the bubble curtain having the group of bubbles <NUM> rising from the water surface.

Therefore, as the bubble curtain regulates the spread of the taken-in floating oil "O," a film-thickness of the floating oil "O" confined inside the area surrounded by the bubble curtain increases.

A method of recovering the floating oil "O" inside an area surrounded by the bubble curtain will be described with reference to <FIG>, <FIG>, <FIG>.

The high-velocity water supply unit <NUM> shown in <FIG> is operated to supply continuously water through the water supply pipe <NUM> toward the nozzle <NUM> at the outlet tip of the water supply pipe <NUM>.

<FIG> shows a state where high-velocity water "J" is jetted continuously from the nozzle <NUM> toward the inlet port of the intake pipe <NUM>. When the high-velocity water "J" is jetted continuously from the nozzle <NUM> toward the inlet port of the intake pipe <NUM>, the mixed fluid of the local water and the floating oil "O" located around the nozzle <NUM> is sucked by an ejector function (Venturi effect).

The sucked mixed fluid of the floating oil "O" and the local water is transported to the oil-water separation tank <NUM> through the oil-water recovery pipe <NUM> shown in <FIG>.

In particular, the high-velocity water "J" destroys the lump of the floating oil "O" inside the intake pipe <NUM>, and as a result, the mixed fluid becomes a kneaded mixture having destroyed product "O'" of the floating oil "O" kneaded with water.

The "water" here includes not only the high-velocity water "J" jetted from the nozzle <NUM> but also the local water such as the surrounding seawater taken in by the high-velocity water "J.

Assuming that there is no bubble curtain, the floating oil "O" spread widely on the sea surface would be sucked, and for this reason, an amount of the local water taken in would increase significantly so that a recovery ratio of the floating oil "O" would decrease.

On the other hand, by the bubble-curtain generation mechanism combined with the ejector <NUM>, the film of floating oil enhanced in thickness by the bubble curtain gathers at the inlet portion of the ejector <NUM> so that the oil recovery ratio increases and the recovery efficiency of the floating oil "O" is significantly improved.

Further, the floating oil is recovered along with water which reduces the recovery ratio thereof for the local water, and as a result, a blockage accident in the intake pipe <NUM> and the oil-water recovery pipe <NUM> is unlikely to occur.

Still further, the suction pump is not used as means for recovering the floating oil "O," and therefore, even if foreign matter such as garbage is mixed in the floating oil "O," there is no concern of suck-in foreign matter's causing failure of the suction pump.

If the floating oil "O" is heavy oil of class C, it deteriorates to high viscosity when being mixed with seawater.

It has been difficult to recover the floating oil "O" deteriorating to high viscosity by the conventional vacuum suction.

On the other hand, the ejector <NUM> can recover the floating oil "O" while jetting high-velocity water "J" to destroy the film of floating oil "O," and as a result, the floating oil "O" can be efficiently recovered by the ejector <NUM> even if the film of floating oil "O" deteriorates to high viscosity.

As shown in <FIG>, the ejector <NUM> is provided with a float <NUM>, and the base end of the ejector <NUM> is supported pivotably by the support frame <NUM> so that the ejector <NUM> can swing in a vertical direction around the front-side horizontal support shaft <NUM> of the support frame <NUM>.

As a result, even if the water surface of the floating oil "O" changes up and down, the height of the oil and water taken in by the ejector <NUM> is automatically adjusted so as to follow a change in water level. As a consequence, the floating oil "O" can be recovered efficiently without being affected by waves.

Even if an ejector portion of the ejector <NUM> floating from the sea surface is exposed to the atmosphere due to the influence of waves, it is possible for the ejector <NUM> to avoid failure of an unrecoverable state caused by air-biting because the ejector <NUM> is not a device of negative-pressure suction type.

With reference to <FIG>, the mixed fluid transported to the oil-water separation tank <NUM> through the oil-water recovery pipe <NUM> is separated into oil and water with the aid of difference in specific gravity.

The main tank <NUM> overflows with the oil separated therein, and the separated oil overflowing the main tank <NUM> is recovered in the oil recovery tank <NUM>.

In general, complete separation of water and oil in the storage tank body <NUM> is technically difficult contrary to expectations.

For this reason, if the water separated in the main tank <NUM> is discharged to the local sea area as it is, for example, the oil component mixed in the separated water is discharged, which may cause water pollution in the local sea area.

By circulating to use the water separated in the main tank <NUM> as high-velocity water to be jetted from the nozzle <NUM> instead of discharging it to the local sea area as it is, an amount of the discharged oil component can be reduced and the deterioration of water quality in the local sea area can be suppressed.

Further, by circulating to use the water separated in the main tank <NUM> for recovery of the floating oil "O," the recovered oil can be concentrated in the main tank <NUM>.

The bubble-curtain generation mechanism formed in the water does not make any direct contact with the floating oil "O," and as a result, it is not necessary to clean the aeration pipe <NUM> and the like.

The ejector <NUM> having finished recovering the floating oil "O" can be cleaned sufficiently by cleaning simply a pipeline thereof having the intake pipe <NUM> and oil-water recovery pipe <NUM> so that the maintenance thereof is easy.

The following two methods can be applied for cleaning the intake pipe <NUM> and oil-water recovery pipe <NUM>:
One is a method (backwashing method) by which a terminal end of the oil-water recovery pipe <NUM> is detached, and cleaning water is flushed through the oil-water recovery pipe <NUM> back from the terminal end.

The other is a method by which the floating-oil recovery device <NUM> is operated, in the sea area where the floating oil "O" is not present, with the terminal end of the oil-water recovery pipe <NUM> being connected to the oil-water separation tank <NUM> so as to clean the intake pipe <NUM> and the oil-water recovery pipe <NUM>.

Hereinafter, other embodiments will be described. In the following descriptions, the same portions as those of the above-described embodiments are added with the same reference numerals, and the detailed descriptions thereof will be omitted.

As described above, the floating-oil recovery device <NUM> can not only recover the floating oil without making any direct contact with the floating oil but also mix an oil treatment agent <NUM> into the floating oil on the sea surface by replacing some pipe of the device <NUM> to decompose the floating oil.

<FIG> shows the nozzle <NUM> and the intake pipe <NUM> provided at the outlet tip of the water supply pipe <NUM>; however, the ejector <NUM> may include the nozzle <NUM>, the intake pipe <NUM>, and the float <NUM> as in the above-described embodiments.

In this example, without the oil-water recovery pipe <NUM> as a result of detachment thereof from an outlet side of the intake pipe <NUM>, the mixed fluid containing the oil treatment agent <NUM> generated in such a detached intake pipe <NUM> is discharged to the floating oil.

The detached intake pipe <NUM> is positioned so that its discharge side (outlet side) faces into the sea.

The discharge side of the intake pipe <NUM> may be bent in a U-shape, or may be straight without being any bent.

In short, it is sufficient that the mixed fluid containing the oil treatment agent <NUM> can be discharged toward the sea surface through the intake pipe <NUM>.

This will be described with reference to <FIG>. In addition to the configuration described above, the floating-oil recovery device <NUM> includes an auxiliary tank <NUM> storing the oil treatment agent <NUM>, an oil treatment agent supply unit <NUM> having a supply pump and a motor, and an auxiliary pipe <NUM> connected between the auxiliary tank <NUM> and the water supply pipe <NUM> on an outlet side of the high-velocity water supply unit <NUM>.

In an embodiment according to the present invention, the oil treatment agent <NUM> is supplied to the nozzle <NUM> by utilizing the water supply pipe <NUM> and the auxiliary pipe <NUM>.

The oil treatment agent <NUM> is a treatment agent in a liquid or powder form capable of decomposing oil by an oxidizing action or a microbial digestive action, and known surfactants and solvents having low toxicity to secondary contamination and marine organisms can be used.

The tip of the auxiliary pipe <NUM> connected to the discharge side of the oil treatment agent supply unit <NUM> joins a portion of the water supply pipe <NUM> so that the oil treatment agent <NUM> can be supplied to the water supply pipe <NUM> through the oil treatment agent supply unit <NUM> and the auxiliary pipe <NUM>.

The water intake source of the water supply pipe <NUM> may be the oil-water separation tank <NUM> shown in <FIG>, and water may be taken in from other than the oil-water separation tank <NUM>.

The water intake source of the water supply pipe <NUM> shown in <FIG> will be described. A water intake pipe <NUM> may be connected to a portion of the three-way switching valve V<NUM> provided on the suction side of the high-velocity water supply unit <NUM>, and water may be transported to the water supply pipe <NUM> through the water intake pipe <NUM> pulled into the sea.

A treatment method using the oil treatment agent in this example will be described.

The high-velocity water supply unit <NUM> and the oil treatment agent supply unit <NUM> are operated to supply continuously water mixed with the oil treatment agent <NUM> to the water supply pipe <NUM>.

When high-velocity water mixed with the oil treatment agent <NUM> is jetted from the nozzle <NUM> toward the inlet port of the intake pipe <NUM>, the floating oil located around the nozzle <NUM>, the high-velocity water mixed with the oil treatment agent <NUM>, and the sucked local water are mixed in the intake pipe <NUM> and are discharged into the sea by the Venturi effect.

The mixed fluid containing the oil treatment agent <NUM> discharged into the sea is discharged in a spiral form through the intake pipe <NUM> so that stirring and mixing of the oil treatment agent <NUM> and the lump layer of the floating oil on the sea surface proceeds.

In this example, the oil treatment agent <NUM> can be mixed with the floating oil on the sea surface to perform the decomposition treatment by a simple operation of replacing some pipe of the floating-oil recovery device <NUM>.

In general, when an oil treatment agent is used, the treatment effect is low if the oil treatment agent is sprayed only, and it is important to stir and mix the oil treatment agent with the oil.

Since the floating oil has an appropriate viscosity, the oil treatment agent needs to be mixed with the floating oil using a mechanical stirring force.

Claim 1:
A floating-oil recovery device (<NUM>) comprising:
a bubble-curtain generation mechanism configured to discharge air into water to generate a bubble curtain in the water so as to increase a thickness of a film of floating oil while regulating spread of the floating oil;
an ejector (<NUM>) configured to recover an oil-water mixed fluid having the floating oil and the water mixed with each other by jetting high-velocity water toward the film of floating oil enclosed with the bubble curtain to destroy the film of floating oil;
an oil-water separation tank (<NUM>) that oil is therein separated to be recovered from the oil-water mixed fluid recovered by the ejector; and
a support frame (<NUM>) to be attached to a portion of a ship (<NUM>),
wherein the bubble-curtain generation mechanism discharges air from a bottom portion of the support frame into the water,
wherein the ejector includes a nozzle (<NUM>) for jetting the high-velocity water toward the film of floating oil enclosed with the bubble curtain to destroy the film of floating oil, and an intake pipe (<NUM>) for taking in the high-velocity water jetted through the nozzle so as to generate negative-pressure suction force, thereby to recover the oil-water mixed fluid into the intake pipe,
wherein the ejector and the oil-water separation tank to be mounted on the ship are connected by an oil-water recovery pipe (<NUM>), and
wherein a water supply pipe (<NUM>) provided with a high-velocity water supply unit (<NUM>) is connected between the oil-water separation tank and the nozzle so that the water separated in the oil-water separation tank is circulated to be supplied to the nozzle as the high-velocity water through the water supply pipe and the high-velocity water supply unit.