JP2022552448A - Flume with bubble screen and bubble screen therefor - Google Patents

Abstract

A channel is provided through which water flows in the direction of flow, the channel comprising a bubble screen disposed at an angle to the direction of water flow, the bubble screen extending substantially from one water directing element to another water directing element. An extending, downstream portion of the bubble screen is provided with a collection area, the bubble strength of the downstream portion of the bubble screen being less than the bubble strength elsewhere within the bubble screen.

Description

FIELD OF THE INVENTION The present invention relates generally to bubble screens for aerating liquids, particularly water.

Bubble screens for distributing and/or dispersing fluids in liquids are generally known. Often the fluid is air and the liquid is a body of water, particularly a watercourse such as a pond, lake, river, canal, stream or part of a sea and/or ocean such as a bay, fjord or cove. Such bubble screens are utilized for a variety of purposes. For example, bubble screens are typically utilized to aerate water for aquaculture, bacterial and/or waste treatment, ice melting, or the like.

It has previously been proposed to use such bubble screens to recover plastic waste, ie plastics, from waterways. Although the upward thrust force provided by known bubble screens can serve to carry plastics to the surface of the water, it effectively removes plastics particularly for further processing before they reach, for example, seas and/or oceans. It has proven difficult in practice to effectively seize the plastic in such a way that it can be recovered.

SUMMARY OF THE INVENTION The present invention seeks to mitigate one or more of the above-mentioned disadvantages while retaining the above-mentioned advantages. In particular, the present invention aims to provide an improved bubble screen flume configuration that is more efficient and allows for improved recovery of plastic waste from the flume.

To that end, the present invention provides a channel through which water flows in the direction of flow, the channel comprising a bubble screen arranged at an angle to the direction of water flow, the bubble screen being separate from the water directing element. Extending substantially to the water directing element, a downstream portion of the bubble screen is provided with a collection area and the bubble intensity of the downstream portion of the bubble screen is greater than the bubble intensity elsewhere within the bubble screen. small.

In general, plastics migrate in the direction of water currents and/or are entrained in the direction of water currents, particularly downstream, for example further waterways, seas or oceans. In some cases, at least part of the water, and thus the plastic, may move substantially in the opposite flow direction, for example due to tidal effects or relatively strong winds. In such cases, additional collection areas may be provided on the opposite portion of the bubble screen with respect to the portion on which the collection areas are provided. In this way, collection areas may be provided on both sides of the bubble screen, thereby allowing improved plastic recovery.

By locating the bubble screen at an angle to the direction of water flow, the plastic seized by the bubble screen can be advantageously guided downstream and towards the collection area. When the bubble strength in the downstream portion of the bubble screen is less than elsewhere in the bubble screen, the plastic can be guided toward the collector with less force. Additionally, the formation of eddies in the water near the collection area can be counteracted. A vortex is a circular flow of water. By providing a lower bubble strength in the downstream portion of the bubble screen, the formation of so-called eddy motion of eddies in the water can be at least partially mitigated. Thereby, the accumulation and/or deposition of plastics in the vicinity of the collecting area, in particular upstream, can be counteracted. In particular, this may facilitate plastic flow through the collection area.

Within the context of this patent specification, the term "water-guiding element" shall be interpreted as an element that at least partially bounds water. For example, water-guiding elements may therefore refer to land bounding water such as embankments, riverbanks or shores, but also to man-made or so-called It may also refer to man-made constructions, and in particular to additional bubble screens. These expressions in this context are understood to be included within the definition of the term "water guiding element".

When the downstream end of the bubble screen curves toward the collector, particularly convexly, the plastic is gradually urged toward the collecting region, thereby pushing the plastic toward the collecting region. A freer flow can be achieved. In this way, the recovery of plastics from waterways can be further improved.

The collection area may be, for example, a waterfront, such as a riverbank, beach, or seaside. Advantageously, the collection area may be equipped with a collector, in particular a water collection system, to further improve the plastic recovery rate. Furthermore, by providing a collection area with a collector, particularly a water collection system, the plastic can be conveniently collected in a more controlled manner.

The presence and/or formation of gaps in the bubble screen can be counteracted when the bubble screen is provided with at least one partial overlap. Loss of plastic that slips through the bubble screen can thereby be reduced. Guidance of the plastic along the bubble screen towards the collection area and/or collector can be advantageously facilitated, particularly when at least one partial overlap forms a cascade within the bubble screen.

By providing the bubble screen with a pressure source configured to supply compressed gas to the bubble screen, a relatively simple and cost effective construction may be provided. Advantageously, the pressure source may be coupled to the upstream end of the bubble screen such that the pressure drop along the bubble screen in the downstream portion, especially due to frictional forces, is greater than elsewhere in the bubble screen. make it possible. In this way, the bubble strength in the downstream portion of the bubble screen can be advantageously less than elsewhere in the bubble screen.

The present invention further provides a bubble screen device, particularly for venting liquids for use in waterways, comprising a plurality of openings along at least a portion of the conduit arrangement, comprising features as described above. a first portion, substantially each opening of the plurality of openings configured to permit gas passage therethrough; and along at least a portion of the first portion aeration of the second portion and elsewhere in the conduit arrangement with openings provided with a ballast module that extends through and is arranged to submerge the bubble screen device in a liquid, in particular water; a vent module configured to adjust the venting capacity of the portion of the conduit arrangement with openings to be less than capacity.

The bubble screen device is provided with a conduit arrangement with a plurality of openings along at least a portion of the conduit arrangement, substantially each opening of the plurality of openings being configured to allow gas to pass therethrough. The bubble screen device can be used to aerate the waterway when provided with a first portion that is . In particular, substantially each opening of the plurality of openings may be configured to allow gas to pass therethrough while acting to oppose the flow of water into the conduit arrangement. The conduit arrangement may be substantially formed from a plastic material such as, for example, polyvinyl chloride (PVC), low density polyethylene (LDPE), high density polyethylene (HDPE), or the like.

When the bubble screen device comprises a second portion provided with a ballast module arranged to submerge the bubble screen in a liquid, the bubble screen device may conveniently be placed within the waterway. A ballast module may comprise a fixed arrangement including, for example, a ballast reservoir, a substantially solid member, and/or at least one anchor. The ballast module may be formed from materials similar to and/or compatible with the materials of the conduit arrangement. Additionally or alternatively, the ballast module may comprise one or more weights, such as metal weights, included therein and/or connected thereto.

By providing a ventilation module configured to adjust the ventilation capacity of a portion of the apertured conduit arrangement to be less than the ventilation capacity elsewhere in the apertured conduit arrangement The bubble strength induced by a portion of the bubble screen device in the middle may be less than the bubble strength induced elsewhere by the bubble screen device. Thus, in particular, the bubble screen device may be provided in a channel having a water flow direction such that the portion of the conduit arrangement with openings having less airflow capacity corresponds to the downstream portion of the bubble screen device. In this way, during use, the plastic can be guided advantageously with less force towards collection areas such as watersides, collectors and/or water collection systems. Additionally or alternatively, during use, the formation of eddies in the water at least in the vicinity of the collection area may be counteracted.

The vent module may comprise a constriction on the conduit arrangement arranged to restrict fluid flow through a portion of the conduit arrangement. In this way, the pressure in a portion of the conduit arrangement may be reduced, thereby reducing the venting capacity of that portion. Therefore, in use, the bubble strength in the corresponding portion of the bubble screen induced by the bubble screen device may advantageously be less than elsewhere in the bubble screen. In particular, the constriction may be provided as a valve to allow control over the amount of constriction within the conduit arrangement. Additionally or alternatively, the constriction may be, for example, a porous membrane/material, a flange or a DeLaval nozzle (ie, a converging-diverging nozzle).

A constriction may be provided on the inner circumference of the mantle surface of the conduit arrangement, such as a flange extending radially inwardly from the mantle surface along at least a portion of the circumference of the inner circumference. Additionally or alternatively, a constriction may be provided on the outer circumference of the mantle surface of the conduit arrangement, for example as a collar or clamping device. This may work particularly well when the conduit arrangement is made substantially of flexible plastic material.

When the vent module comprises a diverging conduit section forming and/or in fluid connection with said part of the conduit arrangement, the pressure in that part of the conduit arrangement is equal to the pressure elsewhere in the conduit arrangement. can be effectively lowered with respect to In this way, the venting capacity of that portion is lower than elsewhere in the conduit arrangement with openings and, in use, the corresponding portion of the bubble screen has a lower bubble strength than other locations within the bubble screen. can have

The ventilation module may comprise at least one textured surface on and/or extending at least partially along the inner circumference of the mantle surface of said portion of the conduit arrangement, wherein at least one The textured surface is rough compared to adjacent portions of the inner perimeter of the mantle surface of the conduit arrangement.

Within the context of this patent specification, the term "textured surface" shall be interpreted as a surface portion that is rough relative to adjacent surface portions of the inner perimeter of the mantle surface of the conduit arrangement. Such adjacent surface portions may in particular have a surface finish that is smooth compared to textured surfaces. Such adjacent surface portions may then in particular be considered non-textured surfaces in the context of the present application. Such a smooth surface may, for reference, be as smooth as the normal (inner) mantle surface of a typical conduit arrangement. Thus, the textured surface may be rough as compared to a surface having a typical surface finish of the mantle surface of conventional conduit arrangements for waterway ventilation.

Advantageously, the ventilation module may comprise a temperature device configured to regulate at least the temperature inside the conduit arrangement. For example, the temperature device may comprise at least one heat insulating element and/or at least one heating element. Thus, by heating or insulating other locations within the conduit arrangement, the pressure there may be higher compared to said portion of the conduit arrangement. Therefore, in use, the bubble strength of the corresponding portion of the bubble screen may increase with respect to said portion of the conduit arrangement. Additionally or alternatively, for example at least one cooling element may be provided as a temperature device in said portion of the conduit arrangement.

The vent module comprises at least one further conduit segment as part of a conduit arrangement with a further plurality of openings along at least a portion of its length, substantially each opening of the further plurality of openings being gaseous. A portion of the at least one further conduit segment configured to allow passage extends along a portion of the conduit arrangement with the openings, whereby a portion of the further plurality of openings is a portion of the plurality of openings. to form a relatively simple structure, while counteracting the possibility of gaps forming in the bubble screen during use at the transition between a portion of the conduit arrangement and the further conduit segment. can affect In this way, during use, plastic slipping through the bubble screen and continuing downstream, for example further waterways, seas and/or oceans, can be mitigated.

at and/or near the overlapping portion during use when at least a portion of the conduit arrangement with the opening and at least a portion of the at least one further conduit segment with the opening are disposed adjacent to each other; Partial blockage of the bubble screen can have counteracting effects.

A tortuous flow path through the conduit arrangement may be provided when the conduit arrangement comprises a loop and a portion of the conduit arrangement is folded back on itself. In this way, a pressure drop can be conveniently achieved across said portion of the conduit arrangement during use. Additionally or alternatively, the portion of the conduit arrangement that folds back on itself may provide additional ventilation elsewhere within the bubble screen as desired. For example, during use, the bubble strength of portions of the bubble screen at greater depths of the waterway may be enhanced.

The present invention further relates to a method for recovering plastic waste from waterways, the method comprising:
- providing between a water-directing element of the flume and another water-directing element a bubble screen extending at an angle to the water flow direction of the flume;
- seizing the plastic waste on the bubble screen and guiding it along the bubble screen towards a collection area in the downstream portion of the bubble screen near the guiding element;
- The bubble strength in the downstream portion of the bubble screen is less than elsewhere in the bubble screen to mitigate vortex formation near the collection area and reduce plastic accumulation and and/or preventing deposition.

The invention is explained more clearly on the basis of exemplary embodiments represented in the drawings. The drawings are only schematic representations of embodiments of the invention, given in the form of non-limiting exemplary embodiments.

1 is a schematic perspective view of a waterway provided with a bubble screen according to the invention; FIG. FIG. 4 is a schematic top view of another flume provided with a bubble screen according to another aspect of the present invention; 1 is a schematic top view of a waterway with a bridge provided with a bubble screen and a further bubble screen that meet at a bridge pile according to one aspect of the present invention; FIG. 1 is a schematic perspective view of a portion of a bubble screen device with a conduit arrangement and ballast module according to one aspect of the present invention; FIG. FIG. 4 is a schematic perspective view of a portion of a bubble screen device provided with diverging conduit sections as vent modules according to a further aspect of the invention; FIG. 4 is a schematic perspective view of a portion of a bubble screen device with additional conduit segments as part of a conduit arrangement according to a still further aspect of the invention;

The same or corresponding parts in the drawings are designated with the same reference numerals.

FIG. 1 shows a waterway 1 . The channel 1 comprises water flowing in a flow direction F and has a width w extending substantially transversely to the water flow direction F. The flume 1 comprises a bubble screen 2 arranged at an angle .alpha. The angle α shown here is about 45°, but any angle within the range of about 1°-90°, such as between about 5°-75° or between about 10°-60° may be selected. Here the bubble screen 2 extends from an embankment as a water directing element 3 to another embankment as a further water directing element 3'. The downstream portion 4 of the bubble screen 2 is provided with a collection area 5 with a water collection system 6 as a collector. Additionally or alternatively, the collection area 5 may be provided as a waterfront, such as a riverbank, seashore or seashore, where plastics are washed ashore, for example. The bubble intensity I in the downstream portion 4 of the bubble screen 2 is less than the bubble intensity I elsewhere in the bubble screen 2 .

In use, plastic waste can be collected from the waterway by clamping the plastic waste over the bubble screen and guiding it along the bubble screen toward a collection area in the downstream portion of the bubble screen near the guide element. A bubble strength in the downstream portion of the bubble screen that is less than the bubble strength elsewhere in the bubble screen is provided to mitigate the formation of vortices near the collection area, thereby reducing the accumulation of plastic and/or plastic near the collection area. It may prevent deposition.

Particles, in particular plastics P, move in water flow direction F, in particular downstream, for example towards further waterways, seas or oceans (not shown). The plastic P is seized by the bubble screen 2 and moved progressively downstream towards the water collection system 6 at the collection area 5 . In some cases, at least part of the water, and thus the plastic P, may move substantially in the opposite flow direction, for example due to tidal effects or relatively strong winds (not shown). In such a case a further collection area is optionally provided at the opposite portion of the bubble screen 2 to the downstream portion 4 of the bubble screen 2 where the water collection system 6 at the collection area 5 is provided. It can optionally be provided with a collector.

The downstream portion 4 of the bubble screen 2 is curved in a particularly convex manner towards the collection area 5 . However, any change in slope between the downstream portion 4 of the bubble screen relative to the rest of the bubble screen 2 may be contemplated, such as a step change or abrupt change.

At least one side 7 of the water collection system 6 provided as collector comprises a mesh wall. The mesh-like wall is configured to screen out particles, in particular plastic P, while allowing water to pass through. The mesh wall may for example have a sieve or so-called mesh size in the range between about 0.1-50 mm, such as between about 0.3-25 mm, or between about 0.5-20 mm. Additionally or alternatively, the mesh wall has particles in the range between 0.1-1000 mm or so-called Configured to screen out particles having a screen size. Screen size shall be interpreted as sieving out at least about 90% of the particles having the specified particle size.

In an exemplary embodiment, gas, in particular compressed gas, is supplied to the bubble screen 2 from a pressure source 8 provided in the downstream portion 4 of the bubble screen 2 . Advantageously, the pressure source 8 may be provided at an upstream portion of the bubble screen 2, ie on the side opposite to that shown here.

FIG. 2 shows a channel having a width W substantially transverse to the water flow direction F that is wider than the width w of the channel of FIG. In this exemplary embodiment the bubble screen 2 is provided with a partial overlap 9 . In particular, the partial overlap 9 forms a cascade 10 at the transition T of the bubble screen 2 . In this way the gap forming at the transition T of the bubble screen may be subjected to counteracting action, thus reducing the risk of particles, in particular plastic P, slipping through the bubble screen 2 . Additionally, as the cascade 10 transitions downstream in flow direction F, downstream guidance of the plastic P along the bubble screen 2 may be facilitated.

FIG. 3 shows a waterway 1 in which a bridge B with stanchions S is provided. In this exemplary embodiment, both the water guiding element 3' and the further water guiding element 3'' are each formed by a different bubble screen 2, where the right hand in FIG. The bubble screen 2 shown on the side extends substantially from the embankment 3 to the other bubble screen 2 shown on the left hand side of Figure 3. The other bubble screens 2 are in turn connected to the embankment 3 to the bubble screen 2. The collection area 5 is provided on the right-hand side of the strut S, but could also be provided on the left-hand side or end of the strut S. Particles, especially plastics P, , is captured by the bubble screen and guided downstream towards a collection area 5 in which a water collection system 6 is provided.

FIG. 4 shows a bubble screen device 12 for aerating liquids. Bubble screen device 12 comprises a first portion 13 provided with a conduit arrangement 14 . In this exemplary embodiment, conduit arrangement 14 is formed substantially from a plastic material such as PVC, LDPE, HDPE, and the like. Conduit arrangement 14 includes a plurality of openings 15 along at least a portion of conduit arrangement 14 . Substantially each opening of the plurality of openings 15 is configured to allow the passage of gas while acting specifically against the influx of water.

The bubble device 12 further comprises a second portion 16 extending along the first portion 13 and in particular substantially over the first portion 13 . The second part 16 is provided with a substantially solid ballast 17 as a ballast module. The ballast 17 is arranged to submerge the bubble screen device 12 in liquid, particularly water. Additionally or alternatively, the ballast module may comprise one or more anchoring elements, for example fixed along at least a portion of the first portion 13 or arranged with variable clearance.

The bubble screen device 12 is arranged to adjust the ventilation capacity of the portion 19 of the apertured conduit arrangement 14 to be less than the ventilation capacity elsewhere within the apertured conduit arrangement 14 . A ventilation module 18 is provided. In this exemplary embodiment, vent module 18 includes a constriction 20 . A constriction 20 is provided on the conduit arrangement 14 and is arranged to restrict fluid flow through a portion of the conduit arrangement 14 . In particular, the constriction 20 is provided as a clamping device on the perimeter 21 of the mantle surface 22 of the conduit arrangement 14 . The vent module 18 in this exemplary embodiment further includes an opening size increase between two rows of subsequent openings of the plurality of openings 15 . A first row of trailing apertures 23 comprises apertures of a first size and a second row of trailing apertures 24 comprises apertures of a second size that is greater than the first size. Of course, the vent module 18 can be provided either as a constriction 20 or as an increased aperture size between two rows.

Conduit arrangement 14 and ballast 17 are secured together, in particular they are secured together by welding. Additionally or alternatively, other securing means such as adhesives or snap connections may be utilized.

Additionally or alternatively, a constriction 20 as a vent module 18 may be provided on the inner circumference 25 of the mantle surface 22 of the conduit arrangement 14 (not shown). For example, the constriction 20 may be an adjustable valve, or a flange extending radially inward from the inner circumference 25 of the mantle surface 22, or the like.

Figure 5 shows a bubble screen device 12 comprising a first portion 13 provided with a conduit arrangement 14 having a plurality of openings 15 therethrough. Substantially each opening is configured to allow the passage of gas while acting specifically against the influx of water. The bubble screen device 12 is further provided with a second portion 16 containing a ballast module 17 for submerging the bubble screen device in liquid. Bubble screen device 12 also includes vent module 18 . Ventilation module 18 comprises a diverging conduit section 26 forming part 19 of conduit arrangement 14 having a lower ventilation capacity than elsewhere in the conduit arrangement (not shown). Alternatively, divergent conduit section 26 may be in fluid connection with said portion 19 of conduit arrangement 14 .

In addition, the vent module 18 of FIG. 5 includes a plurality of vents such that the venting capacity of said portion 19 of the conduit arrangement 14 is less than the venting capacity elsewhere in the conduit arrangement with openings (not shown). includes increased gaps between subsequent openings of opening 15 in .

FIG. 6 shows a bubble screen device 12 according to another aspect of the invention. In this exemplary embodiment, vent module 18 includes an additional conduit segment 27 as part of conduit arrangement 14 . Also, two or more additional conduit segments may be provided, eg, two, three, four, or more (not shown). Further conduit segment 27 comprises a further plurality of openings 28 along at least part of its length. Similar to the plurality of openings 15 described above, substantially each opening of the further plurality of openings 28 is configured to allow the passage of gas while acting specifically against the influx of water. A portion 29 of at least one further conduit segment 27 extends along a portion 30 of the apertured conduit arrangement 14 such that a portion of the further plurality of apertures 28 overlaps a portion of the plurality of apertures 15 . In this exemplary embodiment, the end of conduit arrangement 14 is provided with a plug and gas is supplied from the opposite end. A further end of a further conduit arrangement 27 is also provided with a plug and gas is supplied from the upper right hand side of the schematic. However, the structure from which both the conduit arrangement 14 and the further conduit arrangement 27 extend are both provided with gas from the same end, e.g. Extending beyond portion 30 of configuration 14 may also be contemplated.

Portion 30 of conduit arrangement 14 with openings and portion 29 of further conduit segment 27 are disposed adjacent to each other.

The bubble screen device 12 is configured to orient at least a portion 30 of the conduit arrangement 14 with openings and further orient at least a portion 29 of a further conduit segment 27 with a further plurality of openings 28. 31. In this exemplary embodiment, the openings are specifically oriented by the orientation module 31 towards the side of the bubble screen device 12 such that in use the openings face upstream in the water flow direction. Additionally or alternatively, more than one orientation module may be provided, eg for each at least a portion of each further conduit segment. The orientation module may comprise fixing elements (not shown).

Preferably, any one or all of the exemplary embodiments described above may further comprise at least one pressure source in fluid communication with the conduit arrangement (not shown). In particular, the at least one pressure source is arranged to supply compressed gas. Additionally or alternatively, the bubble screen device may be provided with a manifold arranged to distribute gas supplied from at least one pressure source to a conduit arrangement (not shown). Particularly when additional conduit segments are provided as part of the conduit arrangement, the manifold may distribute gas supplied from the pressure source to the conduit arrangement and the additional conduit segments.

It will be clear to the person skilled in the art that the present invention is not limited to the exemplary embodiments represented here. Many variations are possible. For example, different aspects of the described ventilation modules may be implemented separately or combined. Additional conduit segments as part of the conduit arrangement may, for example, be fluidly connected to additional pressure sources and/or be provided with openings having an increased opening size with respect to the opening size of the plurality of openings. good. For example, substantially each of the (further) plurality of openings or at least one opening may be provided with a nozzle, in particular as a ventilation module.

Such variations would be obvious to one skilled in the art and are considered to fall within the scope of the invention as defined in the appended claims.

REFERENCE SIGNS LIST 1 flume 2 bubble screen 3,3' water directing element 4 downstream section 5 collection area 6 collector 7 at least one side 8 pressure source 9 overlap 10 cascade 11 upstream end 12 bubble screen device 13 first section 14 Conduit Arrangement 15 Multiple Apertures 16 Second Section 17 Ballast Module 18 Vent Module 19 Portion of Conduit Arrangement 20 Constriction 21 Perimeter 22 Mantle Surface 23 First Row of Subsequent Openings 24 Second Row of Subsequent Openings 25 inner circumference 26 diverging conduit section 27 further conduit segment 28 further plurality of openings 29 part of at least one further conduit segment 30 part of conduit arrangement comprising openings 31 orientation module F flow direction P particles, in particular plastic w width W width w wider width with respect to T transition I bubble strength

Claims (24)

A channel through which water flows in the direction of flow, said channel comprising a bubble screen disposed at an angle to the direction of water flow, said bubble screen extending substantially from one water directing element to another water directing element. and a collection area is provided in a downstream portion of the bubble screen, wherein the bubble strength in the downstream portion of the bubble screen is less than the bubble strength elsewhere in the bubble screen. and waterway. 2. Channel according to claim 1, characterized in that the downstream part of the bubble screen is curved, in particular convexly, towards the collecting area. 3. A waterway according to claim 1 or 2, characterized in that the collection area comprises a collector, in particular a water collection system. 4. The flume of claim 3, wherein at least one side of the collector comprises a mesh wall configured to sift particles out and allow water to pass through. 5. The method of claims 1 to 4, characterized in that said bubble screen is provided with at least one partial overlap, in particular said at least one partial overlap forming a cascade within said bubble screen. A waterway according to any one of the paragraphs. Said bubble screen comprises a pressure source configured to supply compressed gas to said bubble screen, in particular said pressure source is coupled to an upstream end of said bubble screen. 6. A waterway according to any one of claims 1 to 5, wherein A bubble screen device for aerating liquids (hereinafter "venting"), especially for use in a waterway according to any one of claims 1 to 6, comprising:
- a first portion provided with a conduit arrangement comprising a plurality of openings along at least a portion of the conduit arrangement, such that substantially each opening of said plurality of openings allows passage of gas; a first portion, comprising:
- a second part extending along at least part of said first part and provided with a ballast module arranged to submerge said bubble screen device in a liquid, in particular water; a second portion;
- a ventilation module arranged to adjust the ventilation capacity of a portion of the apertured conduit arrangement to be lower than the ventilation capacity elsewhere in the apertured conduit arrangement;
A bubble screen device comprising: The vent module comprises a constriction provided on the conduit arrangement arranged to restrict fluid flow through a portion of the conduit arrangement, in particular the constriction provided as a valve. 8. The bubble screen device according to claim 7, characterized in that it is 9. The bubble screen device of claim 8, wherein said constriction is provided on the inner circumference of the mantle surface of said conduit arrangement. 9. A bubble screen device according to claim 7 or 8, characterized in that the constriction is provided on the perimeter of the mantle surface of the conduit arrangement. 11. A bubble screen device according to any one of claims 7 to 10, characterized in that said ventilation module comprises diverging conduit sections forming part of and/or fluidly connecting said conduit arrangement. . 12. A bubble screen device according to any one of claims 7 to 11, characterized in that the ventilation module comprises at least one frictional element arranged within a portion of the conduit arrangement. The ventilation module comprises at least one textured surface on and/or extending at least partially along an inner circumference of a mantle surface of the portion of the conduit arrangement, wherein the at least one textured surface 13. A bubble screen device according to any one of claims 7 to 12, characterized in that the working surface is rough compared to adjacent portions of the inner circumference of the mantle surface of the conduit arrangement. the ventilation module is provided as an increase in the gap between the conduit arrangement, in particular a subsequent opening of a plurality of openings and/or a row of subsequent openings along a portion of the conduit arrangement; or 14. A bubble screen device according to any one of claims 7 to 13, characterized in that it comprises an enlarged portion. The vent module is provided as an opening size increase between the conduit arrangement, in particular a subsequent opening of a plurality of openings and/or a row of subsequent openings along a portion of the conduit arrangement, or 15. A bubble screen device according to any one of claims 7 to 14, characterized in that it comprises an enlarged portion. 16. Any one of claims 7 to 15, characterized in that the ventilation module comprises a temperature device adapted to regulate at least the temperature inside the conduit arrangement, in particular a part of the conduit arrangement. or a bubble screen device according to paragraph 1. said vent module comprising at least one additional conduit segment as part of said conduit arrangement comprising a further plurality of openings along at least a portion of its length;
- substantially each opening of said further plurality of openings is configured to allow passage of gas;
- a portion of the at least one further conduit segment extends along a portion of the conduit arrangement with the openings such that a portion of the further plurality of openings overlaps a portion of the plurality of openings; 17. A bubble screen device according to any one of claims 7 to 16, characterized in that 18. The method of claim 17, characterized in that at least part of the conduit arrangement with openings and at least part of the at least one further conduit segment with openings are arranged adjacent to each other. bubble screen device. 19. A bubble screen device according to any one of claims 7 to 18, characterized in that said conduit arrangement comprises a loop and part of said conduit arrangement is folded back on itself. In combination with at least one further conduit segment, particularly as claimed in claims 17 to 19, it comprises an orientation module arranged to orient at least part of said conduit arrangement with openings, said orientation module comprising 20. The bubble screen device of any one of claims 7 to 19, further arranged to orient at least a portion of said further conduit segment with a further plurality of openings. 21. A bubble screen device according to claim 20, characterized in that said orienting module comprises a fixing element. from claim 7, further comprising at least one pressure source in fluid connection with said conduit arrangement, in particular said at least one pressure source being adapted to supply compressed gas; 22. The bubble screen device of any one of Clauses 21. 23. A manifold as claimed in any one of claims 7 to 22, characterized in that a manifold is provided arranged to distribute gas supplied from at least one pressure source to the conduit arrangement. bubble screen device. A method for recovering plastic waste from a waterway using a waterway or bubble screen, in particular according to any one of claims 1 to 23, comprising:
- providing between a water-directing element of a flow channel and another water-directing element a bubble screen extending at an angle to the water flow direction of said flow channel;
- seizing plastic waste on said bubble screen and guiding it along said bubble screen towards a collection area in the downstream portion of said bubble screen near said guiding element;
- the bubble strength in the downstream portion of the bubble screen is less than the bubble strength elsewhere in the bubble screen to mitigate vortex formation near the collection region, preventing plastic build-up and/or deposition;
A method, comprising:

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