CA1242655A - Oil collecting method - Google Patents
Oil collecting methodInfo
- Publication number
- CA1242655A CA1242655A CA000468208A CA468208A CA1242655A CA 1242655 A CA1242655 A CA 1242655A CA 000468208 A CA000468208 A CA 000468208A CA 468208 A CA468208 A CA 468208A CA 1242655 A CA1242655 A CA 1242655A
- Authority
- CA
- Canada
- Prior art keywords
- ice
- water
- oil
- submerging
- collecting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A20/00—Water conservation; Efficient water supply; Efficient water use
- Y02A20/20—Controlling water pollution; Waste water treatment
- Y02A20/204—Keeping clear the surface of open water from oil spills
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Removal Of Floating Material (AREA)
- Environmental & Geological Engineering (AREA)
- Mechanical Engineering (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Cleaning Or Clearing Of The Surface Of Open Water (AREA)
Abstract
ABSTRACT
A method for collecting oil from a water body covered by broken or solid ice and an arrangement for applying the method are described. The method includes the step of applying an ice submerging device to act on the ice for breaking up solid ice and for submerging oily ice below the water surface. The device may be a vertically movable unit or a vessel floating and moving in the water. The device has through-flow openings for water and and is brought into a position where the openings are below the water surface.
Thereby the water level inside the device is kept substantially below the level of the ambient water in order to produce such a strong water flow into the device that the surrounding ice will be effectively rinsed. The oil washed away from the ice by the water is collected in the device.
The device is so formed that it is operable in an ice field without causing ice piece cloggings.
A method for collecting oil from a water body covered by broken or solid ice and an arrangement for applying the method are described. The method includes the step of applying an ice submerging device to act on the ice for breaking up solid ice and for submerging oily ice below the water surface. The device may be a vertically movable unit or a vessel floating and moving in the water. The device has through-flow openings for water and and is brought into a position where the openings are below the water surface.
Thereby the water level inside the device is kept substantially below the level of the ambient water in order to produce such a strong water flow into the device that the surrounding ice will be effectively rinsed. The oil washed away from the ice by the water is collected in the device.
The device is so formed that it is operable in an ice field without causing ice piece cloggings.
Description
~ - ~ 2426~S
, ' OIL COLLECTING METHOD
The invention relates to a method for collecting oil from a water body covered by broken or solid ice.
Collecting oil from water covered by broken or solid ice is very troublesome. Efficient oil collecting methods have not been developed. Attempts have been made to collect oil from ice by sucking the oil from between the ice pieces, or by collecting the oily ice pieces and have them cleaned. No satisfactory result has been achieved by these means.
The object of the invention is to present a new, efficient method for coliecting oil from ice.
The present invention is directed to a method for collecting oil from a water body covered by broken or solid ice, said method including the steps of applying an ice submerging device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil; moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous displacement of water and ice thereby producing a strong water flow through said openings for obtaining a washing effect on said oily ice and for collecting oil washed away from said ice, and having said device formed without pockets causing substan-tial ice clogging effects.
6~;~
la The invention is based on the observation, that oil in icy waters does not adhere very firmly to the ice, especially not when the oil-ice contact has not lasted for a very long time.
On the other hand, ice pieces and sludge ice effectively prevent the oil from spreading. Thus collecting oil from ice should take part by submerging the ice in the ambient water, thereby rinsing the ice from the oil adhering to its surface and freeing the oil stuck between the ice pieces. The oil thus flushed away ascends together with and through the washing water, which makes it easy to collect. The submerging of ice also produces horizontal water currents in a direction against the ice submerging area~ These currents lead oil located around the ice submerging area towards this area, where it may be collected by means of repeated ice submerging operations.
, ' OIL COLLECTING METHOD
The invention relates to a method for collecting oil from a water body covered by broken or solid ice.
Collecting oil from water covered by broken or solid ice is very troublesome. Efficient oil collecting methods have not been developed. Attempts have been made to collect oil from ice by sucking the oil from between the ice pieces, or by collecting the oily ice pieces and have them cleaned. No satisfactory result has been achieved by these means.
The object of the invention is to present a new, efficient method for coliecting oil from ice.
The present invention is directed to a method for collecting oil from a water body covered by broken or solid ice, said method including the steps of applying an ice submerging device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil; moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous displacement of water and ice thereby producing a strong water flow through said openings for obtaining a washing effect on said oily ice and for collecting oil washed away from said ice, and having said device formed without pockets causing substan-tial ice clogging effects.
6~;~
la The invention is based on the observation, that oil in icy waters does not adhere very firmly to the ice, especially not when the oil-ice contact has not lasted for a very long time.
On the other hand, ice pieces and sludge ice effectively prevent the oil from spreading. Thus collecting oil from ice should take part by submerging the ice in the ambient water, thereby rinsing the ice from the oil adhering to its surface and freeing the oil stuck between the ice pieces. The oil thus flushed away ascends together with and through the washing water, which makes it easy to collect. The submerging of ice also produces horizontal water currents in a direction against the ice submerging area~ These currents lead oil located around the ice submerging area towards this area, where it may be collected by means of repeated ice submerging operations.
2~Z65~
It is important that the level of the water and oil mixture inside the through~flow openings of the ice submerging device is kept substantially below the level of the ambient water. Thereby the water flow against and through the openings of the ice submerging device will be violent enough to produce an effective rinsing of the ice surrounding the ice submerging device.
Patent Specification US 3,959,136 describes an oil collecting method having some similarily with the invention.
lO However, the known method relates only to the collecting of oil from the surface of free water. The devices shown in Figures 1 and 4 of the patent can under no circumstances be used in ice-filled waters, because they would in a minute be totally clogged with ice and thereby be made inoperable.
Hence, the occurence of some solid pieces in the water~ as shown by 24 in Figure 2 of the patent, has no significance with respect to the present invention, because these solid pieces are just occasionally present in the water and have no major influence on the oil collecting process, whereas broken or level ice normally totally covers the water surface, which sets very definite limits for the collecting technique that can be used. Further, the known device does not produce any substantial water flow into the collecting chamber. This means that no effective ice rinsing effect will be produced by using the known device.
For submerging the ice pieces a perforated ice submerging body may be used including a collecting space for water and oil washed away from the ice pieces. The submerging of ice~
the separation of oil and the collecting of oil are conveniently carried out in the same working phase.
The submerging of ice pieces may be accomplished by means of an ice submerging device that is periodically lowered and lifted. When a perforated submerging device is lifted up from the water, water flows out through the holes of the device but the oil remains on the surface of the water inside the submerging device, so that the flow of water out 10 from the interior of the ice submerging device is just an advantage, because it decreases the amount of water collected together with the oil. The flow of water out from the ice submerging device may, when so desired~ be reduced partly or almost totally by providing the holes of the device with non-return valves in the form of resilient closing flaps or the like.
The submerging of iC6 may also take place continuously by arranging an ice submerging device in the bow and/or bottom portion of a vessel moving through the ice field. A col-20 lecting vessel of this kind may be provided with a flatforwardly inclined bow having at and below the water line a great number of oil collecting openings. Thus, the vessel itself acts as an ice submerging device and includes a collecting space for water and oil and possibly also an oi' separating device. The horizontal portion of the bottom of the vessel may also, at least partlv, act as an iC9 washing device.
, .
65~
When applying the method according to the invention, it is important, that the submerging of ice pieces takes part as soon as possible after the moment when the oil has come into the water~ A few days later the adherence of oil to the ice is already noticeably stronger than when the oil is fresh.
Due to this, the method according to the invention should be applied as soon as possible, that is at least within one day from the moment, when the oil came into the water.
The invention also relates to a device designed for applying the described method. In an embodiment of the present inven-tion there is provided an arrangement for collecting oil from a water body covered by broken or solid ice, said arrangement comprising an ice submerging device and means Eor applying said device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil, said arrangement comprising means for moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous dis-placement of water and ice for producing a strong water flow through said openings, thereby collecting oi]. washed away from said ice, said device being formed without pockets causing substantial ice clogging effects.
The invention will now be described, by way of example, with reference to the accompanying drawing, in which ~2~265~
4a - Figure 1 is a sectional view of an embodiment of a periodically operating ice submerging device according to the invention, - Figure 2 is schematical side view, partly in section, of a continuously operating ice submerging vessel according to the invention.
Figure 1 shows a submerging device 1, which is pushed in the direction 2 through an unbroken or broken oil polluted ice field 3, whereby the oil is washed away from the ice due to the rinsing effect of the ambient water. The oil washed awa~
from the ice and some of the oil being free in the water flow in the direction of the arrows 4 through holes 6 at the bottom and on the sides of the submerging device 1 into a ~Z4L265i5 collecting space 5 provided inside the device. The upwards expanding form o'f the lower portion of the submerging device 1 makes it easy to press it down through an ice field and also creates lateral water flow increasing the efficiency of the ice washing and oil collecting opera~tion.
The device 1 is lifted up in the direction of the arrow 7, whereby in particular the holes in its upper part may be closed by means of check valves 9. Then the water inside the device flows away only from below and the oil floating on 10 the water remains in the device, thereby increasing the oil-water ratio of the collected liquid. The device 1 is emptied into a tank or the like in a nearby barge or ship, and the sinking-lifting operation is then repeated.
In the example shown in' Figure 2 a ship 8 either moves through a broken oily ice field 3 or breaks oily level ice by moving therethrough. Due to the movement of the ship the ice pieces are forced downwards along the bow portion of the ship and at its sides. The bow ~ay conveniently be a flat barge-type, bow. The bow portion, part of the bottom and possibly also the sides of the ship are provided with collecting holes 6, through which oil and water flow in the direction of the arrows 4 into a collecting tank 5 located inside the ship 8. Part of the oil flows horizon tally right through the holes being located at or close to the water line of the ship. Another part of the oil follows the ice pieces to a deeper level and flows into the ship through the lower collecting holes.
" ~Z~265S
For making the oil collecting p,rocess more efficient, the oil rising to the surface may be collected separately by known means into a collecting tank. In order to allow continuous operation water must be pumped away from the bottom portion of the collecting tank of the ship 8 or there may be arranged a water escape duct in the rear portion of the ship.
The invention is not limited to the embodiments shown, but several modifications thereof are feasible within the scope 10 of the attached claims.
It is important that the level of the water and oil mixture inside the through~flow openings of the ice submerging device is kept substantially below the level of the ambient water. Thereby the water flow against and through the openings of the ice submerging device will be violent enough to produce an effective rinsing of the ice surrounding the ice submerging device.
Patent Specification US 3,959,136 describes an oil collecting method having some similarily with the invention.
lO However, the known method relates only to the collecting of oil from the surface of free water. The devices shown in Figures 1 and 4 of the patent can under no circumstances be used in ice-filled waters, because they would in a minute be totally clogged with ice and thereby be made inoperable.
Hence, the occurence of some solid pieces in the water~ as shown by 24 in Figure 2 of the patent, has no significance with respect to the present invention, because these solid pieces are just occasionally present in the water and have no major influence on the oil collecting process, whereas broken or level ice normally totally covers the water surface, which sets very definite limits for the collecting technique that can be used. Further, the known device does not produce any substantial water flow into the collecting chamber. This means that no effective ice rinsing effect will be produced by using the known device.
For submerging the ice pieces a perforated ice submerging body may be used including a collecting space for water and oil washed away from the ice pieces. The submerging of ice~
the separation of oil and the collecting of oil are conveniently carried out in the same working phase.
The submerging of ice pieces may be accomplished by means of an ice submerging device that is periodically lowered and lifted. When a perforated submerging device is lifted up from the water, water flows out through the holes of the device but the oil remains on the surface of the water inside the submerging device, so that the flow of water out 10 from the interior of the ice submerging device is just an advantage, because it decreases the amount of water collected together with the oil. The flow of water out from the ice submerging device may, when so desired~ be reduced partly or almost totally by providing the holes of the device with non-return valves in the form of resilient closing flaps or the like.
The submerging of iC6 may also take place continuously by arranging an ice submerging device in the bow and/or bottom portion of a vessel moving through the ice field. A col-20 lecting vessel of this kind may be provided with a flatforwardly inclined bow having at and below the water line a great number of oil collecting openings. Thus, the vessel itself acts as an ice submerging device and includes a collecting space for water and oil and possibly also an oi' separating device. The horizontal portion of the bottom of the vessel may also, at least partlv, act as an iC9 washing device.
, .
65~
When applying the method according to the invention, it is important, that the submerging of ice pieces takes part as soon as possible after the moment when the oil has come into the water~ A few days later the adherence of oil to the ice is already noticeably stronger than when the oil is fresh.
Due to this, the method according to the invention should be applied as soon as possible, that is at least within one day from the moment, when the oil came into the water.
The invention also relates to a device designed for applying the described method. In an embodiment of the present inven-tion there is provided an arrangement for collecting oil from a water body covered by broken or solid ice, said arrangement comprising an ice submerging device and means Eor applying said device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil, said arrangement comprising means for moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous dis-placement of water and ice for producing a strong water flow through said openings, thereby collecting oi]. washed away from said ice, said device being formed without pockets causing substantial ice clogging effects.
The invention will now be described, by way of example, with reference to the accompanying drawing, in which ~2~265~
4a - Figure 1 is a sectional view of an embodiment of a periodically operating ice submerging device according to the invention, - Figure 2 is schematical side view, partly in section, of a continuously operating ice submerging vessel according to the invention.
Figure 1 shows a submerging device 1, which is pushed in the direction 2 through an unbroken or broken oil polluted ice field 3, whereby the oil is washed away from the ice due to the rinsing effect of the ambient water. The oil washed awa~
from the ice and some of the oil being free in the water flow in the direction of the arrows 4 through holes 6 at the bottom and on the sides of the submerging device 1 into a ~Z4L265i5 collecting space 5 provided inside the device. The upwards expanding form o'f the lower portion of the submerging device 1 makes it easy to press it down through an ice field and also creates lateral water flow increasing the efficiency of the ice washing and oil collecting opera~tion.
The device 1 is lifted up in the direction of the arrow 7, whereby in particular the holes in its upper part may be closed by means of check valves 9. Then the water inside the device flows away only from below and the oil floating on 10 the water remains in the device, thereby increasing the oil-water ratio of the collected liquid. The device 1 is emptied into a tank or the like in a nearby barge or ship, and the sinking-lifting operation is then repeated.
In the example shown in' Figure 2 a ship 8 either moves through a broken oily ice field 3 or breaks oily level ice by moving therethrough. Due to the movement of the ship the ice pieces are forced downwards along the bow portion of the ship and at its sides. The bow ~ay conveniently be a flat barge-type, bow. The bow portion, part of the bottom and possibly also the sides of the ship are provided with collecting holes 6, through which oil and water flow in the direction of the arrows 4 into a collecting tank 5 located inside the ship 8. Part of the oil flows horizon tally right through the holes being located at or close to the water line of the ship. Another part of the oil follows the ice pieces to a deeper level and flows into the ship through the lower collecting holes.
" ~Z~265S
For making the oil collecting p,rocess more efficient, the oil rising to the surface may be collected separately by known means into a collecting tank. In order to allow continuous operation water must be pumped away from the bottom portion of the collecting tank of the ship 8 or there may be arranged a water escape duct in the rear portion of the ship.
The invention is not limited to the embodiments shown, but several modifications thereof are feasible within the scope 10 of the attached claims.
Claims (11)
1. A method for collecting oil from a water body covered by broken or solid ice, said method including the steps of applying an ice submerging device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil; moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous displacement of water and ice thereby producing a strong water flow through said openings for obtaining a washing effect on said oily ice and for collecting oil washed away from said ice, and having said device formed without pockets causing substantial ice clogging effects.
2. A method according to claim 1, in which said through-flow openings are arranged to lead from said water body to a space leading to or forming a collecting space for oil and water, the level of oil and water in said space being kept at a level substantially below the level of said water body so as to produce a strong flow through said openings into said space.
3. A method according to claim 1, in which said ice submerg-ing device is a periodically lowered and lifted hollow body having in its bottom collecting holes, through which water and oil is collected into said body.
4. A method according to claim 1, in which said ice submerg-ing device is a periodically lowered and lifted hollow body having in its bottom and in its side collecting holes, through which water and oil are collected into said body.
5. A method according to claim 3 or 4, in which said ice submerging device has a downwards tapered perforated portion.
6. A method according to claim 1, in which said submerging of ice is carried out as a continuous operation by means of a vessel floating and moving in said water and being provided with ice submerging and oil collecting means in its bow and/or bottom portion.
7. A method according to claim 1, 2 or 6, in which said submerging of ice is carried out as soon as possible after the moment, when said oil has come into contact with said ice, and at least within one day from said moment.
8. An arrangement for collecting oil from a water body covered by broken or solid ice, said arrangement comprising an ice submerging device and means for applying said device to act on said ice for breaking up solid ice and for submerging oily ice below the surface of said water body, said device being provided with through-flow openings for water and oil, said arrangement comprising means for moving said device against oily ice for positively pushing said ice below the level of said water body during simultaneous displacement of water and ice for producing a strong water flow through said openings, thereby collecting oil washed away from said ice, said device being formed without pockets causing substantial ice clogging effects.
9. An arrangement according to claim 8, in which there are through-flow openings for collecting oil and water in the bottom as well as in the side surface of said ice submerging device.
10. An arrangement according to claim 8 or 9, in which the lower portion of said ice submerging device is perforated and downwards tapered.
11. An arrangement according to claim 8 or 9, in which said through-flow openings are provided with means preventing, at least partly, flow in a direction out from said device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI834264A FI73029C (en) | 1983-11-21 | 1983-11-21 | Oil collection procedure. |
| FI834264 | 1983-11-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1242655A true CA1242655A (en) | 1988-10-04 |
Family
ID=8518101
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000468208A Expired CA1242655A (en) | 1983-11-21 | 1984-11-20 | Oil collecting method |
Country Status (3)
| Country | Link |
|---|---|
| CA (1) | CA1242655A (en) |
| FI (1) | FI73029C (en) |
| SE (1) | SE456828B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5527461A (en) * | 1994-06-02 | 1996-06-18 | Hill; Gordon A. | Airlift oil scavenger |
| WO2009056687A2 (en) * | 2007-10-31 | 2009-05-07 | Mobimar Oy | Oil combatting vessel |
| EP2961891A4 (en) * | 2013-03-01 | 2016-08-24 | Lamor Corp Ab | Device for collecting oil |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI106969B (en) * | 1999-03-11 | 2001-05-15 | Suomen Ympaeristoekeskus | Method and apparatus for collecting oil in ice blocks |
| CN105129909B (en) * | 2015-07-31 | 2017-12-12 | 重庆硕奥科技有限公司 | Sea pollution by oil clears up the application method of cooling device |
-
1983
- 1983-11-21 FI FI834264A patent/FI73029C/en not_active IP Right Cessation
-
1984
- 1984-11-16 SE SE8405772A patent/SE456828B/en not_active IP Right Cessation
- 1984-11-20 CA CA000468208A patent/CA1242655A/en not_active Expired
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5527461A (en) * | 1994-06-02 | 1996-06-18 | Hill; Gordon A. | Airlift oil scavenger |
| WO2009056687A2 (en) * | 2007-10-31 | 2009-05-07 | Mobimar Oy | Oil combatting vessel |
| WO2009056687A3 (en) * | 2007-10-31 | 2010-03-18 | Mobimar Oy | Oil combatting vessel |
| US8343358B2 (en) | 2007-10-31 | 2013-01-01 | Mobimar Oy | Oil combatting vessel |
| RU2475406C2 (en) * | 2007-10-31 | 2013-02-20 | Мобимар Ой | Ship to fight oil spills |
| EP2961891A4 (en) * | 2013-03-01 | 2016-08-24 | Lamor Corp Ab | Device for collecting oil |
| US9903083B2 (en) | 2013-03-01 | 2018-02-27 | Lamor Corporation Ab | Device for collecting oil |
| RU2658364C2 (en) * | 2013-03-01 | 2018-06-21 | Ламор Корпорейшн Аб | Device for collecting oil |
Also Published As
| Publication number | Publication date |
|---|---|
| SE8405772L (en) | 1985-05-22 |
| FI73029C (en) | 1987-08-10 |
| FI834264A0 (en) | 1983-11-21 |
| FI73029B (en) | 1987-04-30 |
| FI834264A (en) | 1985-05-22 |
| SE456828B (en) | 1988-11-07 |
| SE8405772D0 (en) | 1984-11-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4175039A (en) | Washer/separator system for drilling cuttings in water environment oil wells | |
| US3804251A (en) | Floatage collecting apparatus and method | |
| US4165282A (en) | Oil recovery method and apparatus | |
| FI112105B (en) | Oil collecting device | |
| US4398551A (en) | Hydraulic surface cleaning apparatus | |
| CA1242655A (en) | Oil collecting method | |
| US3690464A (en) | Oil recovery vessel for the removal of oil and other polluting matter floating on the water surface | |
| US4277334A (en) | Oil and debris skimmer | |
| WO1999034894A1 (en) | Apparatus for separating a low density liquid from a high density liquid | |
| US4597863A (en) | Hydrocarbon recovery system | |
| DE1634022A1 (en) | Method and device for the removal of oily or other waste floating on water surfaces | |
| JP2001070705A (en) | Method and apparatus for treating recovered liquid | |
| FI75014C (en) | Arrangement at a vessel for the collection of existing oil at the water surface, especially among ice floes. | |
| US4410426A (en) | Beach cleaning method and apparatus therefor | |
| USRE30729E (en) | Floatage collecting apparatus and method | |
| FI80746C (en) | ANORDNING VID ETT FARTYG FOER UPPSAMLING AV OLJA ELLER ANDRA FOERORENINGAR FRAON VATTENYTAN. | |
| JP4074927B2 (en) | Cleaning processing equipment | |
| US4366052A (en) | Controlled flooding and skimming apparatus for beach cleaning | |
| US2356469A (en) | Attachment for dredges and similar devices | |
| JPH0771019A (en) | Removing method of dregs and/or oily materials in water to be treated and preliminary treating device and water purifier by use thereof | |
| US4302339A (en) | Beach cleaning method | |
| DE3640847A1 (en) | Process for disposing of waste from fat separator units | |
| JPS5491863A (en) | Method and device for crude oil sludge removal | |
| CN111252909A (en) | Sewage purification device with resin curing laccase filter layer | |
| DE1169854C2 (en) | Device for collecting flotsam or substances floating on a water surface |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |