U.S. patent application number 15/747645 was filed with the patent office on 2018-07-26 for self-closing sheet for encapsulating and dumping a bulk of material.
The applicant listed for this patent is Danmarks Tekniske Universitet. Invention is credited to Jacob Hjelmager Jensen.
Application Number | 20180208277 15/747645 |
Document ID | / |
Family ID | 53835947 |
Filed Date | 2018-07-26 |
United States Patent
Application |
20180208277 |
Kind Code |
A1 |
Jensen; Jacob Hjelmager |
July 26, 2018 |
SELF-CLOSING SHEET FOR ENCAPSULATING AND DUMPING A BULK OF
MATERIAL
Abstract
The invention relates to a sheet (1) to be placed in relation to
a split barge (100) for encapsulating a bulk of material (101) to
be dumped when the bulk of material is released, the sheet
comprising a material containing portion (4) and at least one
material free portion (3) extending from at least two opposed sides
of the material containing portion, wherein that the immersed sheet
encapsulating the bulk of material comprises an encapsulated body
(20) encapsulated by the material containing (4) portion and a
self-closing portion (22) being at least a part of the material
free portion (3) both extending from an assembly point (21),
wherein a closing length of the self-closing portion (22)
correspond to at least 5% of the circumventing length of the
encapsulated body (20), the circumventing length extending from the
assembly point (21) to the assembly point (21). The invention
further relates to a method of encapsulating a bulk of material by
means of a sheet.
Inventors: |
Jensen; Jacob Hjelmager;
(Roskilde, DK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Danmarks Tekniske Universitet |
Kgs. Lyngby |
|
DK |
|
|
Family ID: |
53835947 |
Appl. No.: |
15/747645 |
Filed: |
July 11, 2016 |
PCT Filed: |
July 11, 2016 |
PCT NO: |
PCT/EP2016/066414 |
371 Date: |
January 25, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B63B 35/306 20130101;
E02F 7/065 20130101; E02F 7/04 20130101; B65D 88/78 20130101 |
International
Class: |
B63B 35/30 20060101
B63B035/30; B65D 88/78 20060101 B65D088/78 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 12, 2015 |
EP |
15180716.1 |
Claims
1. A sheet being placeable in relation to a split barge and
configured for encapsulating a bulk of material to be dumped when
the bulk of material is released, the sheet comprising a material
containing portion and at least one material free portion extending
from at least two opposed sides of the material containing portion,
wherein the sheet encapsulates the bulk of material and comprises
an encapsulated body encapsulated by the material containing
portion and a self-closing portion being at least a part of the
material free portion both extending from an assembly point,
wherein a closing length of the self-closing portion correspond to
at least 5% of the circumventing length of the encapsulated body,
the circumventing length extending from the assembly point to the
assembly point.
2-18. (canceled)
19. The sheet according to claim 1, wherein the sheet further
comprises at least one mechanical seal and/or at least one chemical
seal.
20. The sheet according to claim 1, wherein the at least one
mechanical seal comprises a hook and loop fastener or a mushroom
fastener.
21. The sheet according to claim 19, wherein the at least one
chemical seal comprises an adhesive.
22. The sheet according to claim 1, wherein the sheet further
comprises at least one mounting element for attaching the sheet to
the split barge, wherein the mounting element is configured for
disengaging upon the weight of the sinking sheet encapsulating the
bulk of material.
23. The sheet according to claim 22, wherein the mounting element
comprises a strap and a snap-off element.
24. The sheet according to claim 23, wherein the snap-off element
comprises a weak link along the strap configured for being
broken.
25. The sheet according to claim 23, wherein the snap-off element
comprises a snap-off button.
26. The sheet according to claim 19, wherein the mounting element
and/or the mechanical seal comprises a magnet.
27. The sheet according to claim 1, wherein the sheet is made of a
degradable material.
28. The sheet according to claim 1, wherein the sheet is made of a
permanent material.
29. The sheet according to claim 1, wherein the self-closing
portion of the sheet is made from a different material than the
remaining sheet.
30. The sheet according to claim 1, wherein the sheet comprises an
outer sheet configured for being attached to the split barge such
that the sheet constitutes an inner sheet configured for being in
contact with the bulk of material.
31. A method of encapsulating a bulk of material by a sheet
comprising; arranging the sheet in or under a split barge, filling
the sheet or the split barge with the bulk of material, opening the
split barge so that the weight of the bulk of material starts
sinking the sheet towards a seabed, wherein the method further
comprises encapsulating the bulk of material followed by leading
the sheet into an assembly point by a water pressure induced around
the sinking sheet and engaging the self-closing of the self-closing
portion.
32. The method according to claim 31, wherein the sheet comprises a
mechanical and/or chemical seal, wherein the method further
comprises engaging the mechanical and/or chemical seal concurrently
with engaging the self-closing of the self-closing portion.
33. The method according to claim 31, wherein the sheet comprises
the outer sheet such that the sheet constitutes an inner sheet,
wherein the method further comprises retrieving the outer sheet to
the split barge.
34. A method of encapsulating a bulk of material by a sheet
comprising; arranging the sheet in a split barge, filling the sheet
with the bulk of material, encapsulating the bulk of material,
engaging a mechanical and/or chemical seal, and opening the split
barge releasing the encapsulated bulk of material, which sinks
towards a seabed.
35. The method according to claim 34 wherein the sheet comprises
the outer sheet such that the sheet constitutes an inner sheet,
wherein the method further comprises retracting the outer sheet on
board the split barge.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a sheet to be placed in relation to
a split barge for encapsulating a bulk of material to be dumped
when the bulk of material is released, the sheet comprising a
material containing portion and a material free portion extending
from at least two opposed sides of the material containing portion.
The invention further relates to a method of encapsulating a bulk
of material by means of a sheet.
BACKGROUND OF THE INVENTION
[0002] Dredging--the excavation of materials such as sediment of
soil, sand, clay, slit and/or rocks from beneath bodies of water
such as rivers and oceans--is a large global industry that makes
marine construction projects possible, and supplies a large portion
of the world's sand consumption.
[0003] The industry reuses a large portion of the 9 billion cubic
meter of matter it excavates every year for construction purposes,
coastal feeding or landfilling. However not all material is
suitable. Somewhere between 22-25% of the annual dredged volume
comprises dredge spoils and fine sediments which requires disposal,
as its small grain size makes it unusable for practical uses. The
fine sediment is therefore instead dumped offshore where it may
disturb the aquatic ecosystems, often with adverse long term
effects, as the dumped sediment can remain in the water column for
up to half a year where it may kill small organisms and in some
cases cause deoxygenation.
[0004] Due to the potential hazards of oceanic dumping, the
dredging industry is being met with increasingly high dumping
costs, both through rising environmental fees and though the
increased difficulty in finding suitable dumping sites close to
excavation sites. Initiatives have therefore been taken towards
minimizing the sediment pollution caused by dumping. WO10116013
disclose e.g. a hopper barge containing a geotextile insulating bag
containing a bulk of material that in some degree prevents
dispersion of material when dumped. But as the geotextile bag does
not encapsulate the material some sediment pollution may still take
place.
[0005] Alternatively WO9729247 discloses an example of known
flexible containers consisting of a textile fabric for receiving
loose or lightly cohesive material via a closeable filling opening
in order to form a bulk for deposition at a selected place, wherein
the flexible container is sealed before dumping the bulk. A
disadvantage of the known operations for sealing the flexible
containers is that they are rather time-consuming.
[0006] Developers and contractors who hire dredging companies on
the other hand, are encountering higher raw material costs, as the
price of raw materials such as rocks, gravel and sand is rising due
to demand and depletion of these resources in certain regions. At
the same time, dredging companies are dumping in excess of 2
billion cubic meter of sediment annually, often close to
construction sites.
[0007] It is therefore desirable to prevent dumped sediment from
spreading throughout the water column in an easy and cost effective
way and hereby reduce the strain on the already burdened global
marine environment. Furthermore it is desirable to provide a way of
increasing the utilization of dredged material by connecting the
disjoint markets; dredging disposal and construction resources.
SUMMARY OF THE INVENTION
[0008] Disclosed herein is a sheet being placeable in relation to a
split barge and configured for encapsulating a bulk of material to
be dumped when the bulk of material is released, the sheet
comprising a material containing portion and at least one material
free portion extending from at least two opposed sides of the
material containing portion, wherein the immersed sheet
encapsulates the bulk of material and comprises an encapsulated
body encapsulated by the material containing portion and a
self-closing portion being at least a part of the material free
portion both extending from an assembly point, wherein a closing
length of the self-closing portion correspond to at least 5% of the
circumventing length of the encapsulated body, the circumventing
length extending from the assembly point to the assembly point.
[0009] The sheet may be configured for being released from the
split barge before the sheet encapsulates the bulk of material,
such that the sheet when being immersed comprises the encapsulated
body encapsulated by the material containing portion and the
self-closing portion wherein the self-closing portion may at least
be a part of the material free portion.
[0010] The circumventing length may be defined as the length of the
sheet from assembly point to assembly point when the sheet
circumvents the body to be encapsulated.
[0011] The self-closing portion may at least be a part of a closing
length extending from an assembly point towards a free end of the
sheet. The free end of the sheet may be a free edge of the material
free portion.
[0012] The closing length of the self-closing portion may be
between 5%, i.e. one twentieth, and the double of the circumventing
length of the encapsulated body, more preferably may the closing
length be between one fourth and one and a half of the
circumventing length of the encapsulated body.
[0013] The sheet may hereby be configured for being released from
the split barge before the sheet encapsulates the bulk of material
and/or without pre-closing and/or pre-sealing the sheet. This may
eliminate the need of handling of the sheet after the sheet has
been arranged on the split barge.
[0014] The material containing portion of the sheet may be arranged
so that the material containing portion adjoins an inside or an
outside surface of the split barge, i.e. an outside surface of the
material containing portion may be arranged so that the material
containing portion adjoins an inside surface of the split barge or
an inside surface of the material containing portion may be
arranged so that the material containing portion adjoins an outside
surface of the split barge.
[0015] The material containing portion and the sheet in its
entirety may comprise a centreline configured for being arranged
along a centreline in the bottom of the split barge. The centreline
of the split barge may be parallel to the sides, i.e. port and
starboard, of the split barge and be placed mid between the two
sides. The centreline of the material containing portion and the
sheet in its entirety may divide the material containing portion
and the sheet into the two opposite sides. The sheet may
furthermore comprise another centreline perpendicular to above
defined centreline also dividing the sheet into two opposite
portions.
[0016] The material containing portion may be sized after the split
barge the sheet is to be arranged in or on. The material containing
portion may furthermore be formed into a bag or the like fitting
into the split barge the sheets is to be arranged in or on.
[0017] In an embodiment the material free portion may comprise at
least two material free portions extending from at least two
opposed sides of the material containing portion, whereas the
opposite sides each extends from one of the centrelines of the
sheet. The two material free portions may extend from the sides of
the material containing portion arranged along the sides, i.e. port
and starboard, of the split barge. The material free portion on
each of the opposite sides of the material containing portion may
extend or may be arranged to extend approximate with the same
length from the material containing portion. The material free
portion on each of the opposite sides of the material containing
portion may extend or may be arranged to extend with different
lengths from the material containing portion.
[0018] Alternatively the at least one material free portion may
comprise one material free portion extending from the entire
circumference of the edge of the material containing portion
wherein at least two opposite sides of the material free portion
approximate may extend or may be arranged to extend approximate
with the same length from the material containing portion.
[0019] The material free portions may extend along an entire side
of the material containing portion and/or along part of a side of
the material containing portion. The material free portion may be
an edge portion of the material containing portion or an added edge
portion attached to the material containing portion.
[0020] As the bulk of material is released form the split barge and
the weight of the bulk of material starts sinking the sheet towards
the seabed, the sheet may be a self-closing sheet in the sense that
the material containing portion of the sheet is urged around the
bulk of material forming an encapsulated body and a tale, i.e. the
self-closing portion comprising adjoining material free portions
extending from at least opposite sides of the material containing
portion. This may be achieved by the water pressure induced around
the sinking sheet without applying any other means for closing
and/or sealing the sheet. The assembly point between the
encapsulated body and the self-closing portion may likewise be
formed during sinking of the sheet encapsulating the bulk of
material.
[0021] The circumventing length of the encapsulated body may be
defined as the length from where one side of the sheet meets the
opposite side of the sheet in the assembly point.
[0022] The self-closing portion may at least comprise the one or
more material free portions or a part of the one or more material
free portions. The self-closing portion may extend from the
assembly point and towards the water surface.
[0023] The advantage of enclosing the bulk of material is that the
spread of the material in the water column between the water
surface and the seabed or the bottom of a lake, river or the like
is prevented when dumping the material.
[0024] The self-closing principle is possible due to the pressure
field induced around the sinking sheet making the material free
portions of the sheet adjoin. This as the pressure field sucks out
water from within the sheet and thereby almost instantaneously
urges the material free portions of the sheet towards each other.
When the encapsulated body reaches the seabed, the sheet may remain
closed, be partially open or open fully, in which case the sediment
may be allowed to spread across the seabed.
[0025] The material to be dumped may be a substantially loose,
suspendable and/or cohesive material e.g. sediment of soil, sand,
clay, slit, rocks or other ground material.
[0026] By split barge is meant any barge, ship or vessel configured
for dumping a bulk of material by splitting the hull or opening a
bottom part such as one or more gates or flaps arranged in the hull
of the barge, ship, vessel or the like.
[0027] The split barge may comprise more than one compartment,
wherein each compartment is configured to hold a sheet.
[0028] A support element may be arranged on the split barge for
supporting the material free portion of the sheet when the sheet is
arranged on the split barge and during the filling of the split
barge with material. The support element may be one or more racks
arranged along the edge of the split barge. The support element may
be configured for holding the material free portion of the sheet on
the outside or inside surface of the split barge.
[0029] In one or more embodiments the sheet further comprises a
mechanical and/or chemical sealing. The mechanical and/or chemical
sealing may be added to the sheet for self-sealing the sheet
concurrently with self-closing the sheet.
[0030] The mechanical and/or chemical sealing may be added to the
sheet for being able to control when the sediment may be allowed to
spread across the seabed. Alternatively the mechanical and/or
chemical sealing may be added to the sheet if the encapsulated
material is to be used as temporary building blocks. The sheet may
be suitable for any shape including both approximately quadratic
and approximately rectangular building blocks. The building blocks
may advantageously be dumped at a construction site for re-bunding
close to the dredging site.
[0031] The mechanical and/or chemical sealing may be arranged at
least in the self-closing portion of the sheet and at least on the
inside surface of the sheet. This as it is the inside surface of
the self-closing portions which adjoins during sinking of the sheet
encapsulating the bulk of material.
[0032] Alternatively the mechanical and/or chemical sealing may
both be attached on the inside surface and the outside surface of
the sheet. The mechanical and/or chemical sealing may be attached
on the outside surface of the sheet in one or both of the opposite
sides of the sheet. This may allow that the bulk of material may be
encapsulated by the sheet and sealed before releasing the sheet
encapsulating the bulk of material from the split barge.
[0033] The mechanical and/or chemical sealing may thereby be
configured for being engaged either before or after opening the
split barge.
[0034] In one or more embodiments the mechanical sealing comprises
a hook and loop fastener or a mushroom fastener. The hook and loop
fastener may be known as Velcro.RTM.. The mushroom fastener may
e.g. be a mushroom hook fastener known as Pressotex.RTM.. The hook
and loop fastener or mushroom fastener may at least be attached on
the inside surface of the self-closing portion of the sheet. The
hook and loop fastener or mushroom fastener may additionally be
attached on the outside surface of the sheet in one or both of the
opposite sides of the sheet.
[0035] Alternatively the mechanical sealing may comprise at least
one retaining barb arranged on a strap wherein the strap may be
attached to the split barge. The strap may tightened around the
self-closing portion of the sheet and engage the barb as the
encapsulated bulk of material sinks. The strap may break or
snap-off in a weak link or the like as the strap is fully
outstretched between the split barge and the sinking encapsulated
bulk of material.
[0036] In one or more embodiments the chemical sealing comprises an
adhesive. The chemical sealing may be a mushroom fastener with an
adhesive known as Duotec.RTM.. The adhesive may be applied at least
to the inside surface of the self-closing portion of the sheet. The
adhesive may additionally be applied on the outside surface of the
sheet in one or both of the opposite sides of the sheet.
[0037] In one or more embodiments the sheet further comprises at
least one mounting element for attaching the sheet to the split
barge wherein the mounting element is configured for disengaging
upon the weight of the sinking sheet encapsulating the bulk of
material.
[0038] The sheet may be mounted to the split barge by means of a
mounting and release system for mounting and releasing the sheet
to/from the split barge. The mounting and release system may
comprise a corresponding mounting element, wherein the mounting
element is disengaged from the corresponding mounting element upon
the weight of the sinking sheet encapsulating the bulk of
material.
[0039] The mounting element may be any element on or in the sheet
suitable for being used for unfolding the sheet and arranging the
sheet on the split barge and/or to attach the sheet directly or
indirectly to the split barge. The mounting element may be used for
attaching the edge of the sheet to an upper edge or the side of the
split barge.
[0040] The sheet may be released from the split barge after the
split barge opens and when the sheet is fully outstretch from a
centre line or a centre point of the sheet to the edge of the sheet
as the weight of the material on the sheet pushing the sheet into
the water. This may be an advantages as the mounting of the edge of
the sheet may facilitate that the sheet is fully outstretch when it
enters the water so that the formation of an assembly point and
self-closing portion may become more efficient. Furthermore this
may together with the self-closing concept render the dumping of
encapsulated material quick and easy without the need for any
manpower for pre-closing and/or pre-sealing the sheet.
[0041] In one or more embodiments the mounting element comprises a
strap and a snap-off element. The corresponding mounting element
may be a hook attached directly or indirectly to the split barge.
The hook may be a conventional open and/or closed load bearing
hook.
[0042] In one or more embodiments the snap-off element comprises a
weak link along the strap configured for being broken. The weak
link may be broken by the weight of the sinking sheet encapsulating
the bulk of material.
[0043] In one or more embodiments the snap-off element comprises a
snap-off button. The snap-off button may be placed along the length
of the strap so that the strap is split into two portions when the
snap-off button is disengaged. Or the snap-off button may be placed
in one of the ends of the strap.
[0044] It may be obvious for a skilled person that the mechanical
and/or chemical sealing additionally may be used as a mounting
element and that the mounting element additionally may be used as a
mechanical and/or chemical sealing.
[0045] In one or more embodiments the mounting element and/or the
mechanical sealing comprises a magnet.
[0046] One or more magnetic tapes and/or a plurality of magnets may
be attached on or in the self-closing portion of the sheet. The
magnets may be suitable for releasably attaching the sheet to the
split barge as the split barge may be made of steel, whereas the
magnets preferably is arranged at least in the edge of the sheet.
The magnets may alternatively or concurrently be suitable for
obtaining a self-sealing of the self-closing portion of the sheet
whereas the magnets either may be arranged in the edge portion
and/or so that they substantially covers the self-closing portion
of sheet. The magnets may be suitable for sealing the sheet both
before and after opening the split barge.
[0047] Alternatively the mounting element may comprise a strap
without a snap-off element and a rope may comprise a snap-hook with
a release mechanism, whereas the snap-hook may be fixed in on end
to the rope and releasably attached to the strap in the other end.
The release mechanism may be tricked by a pull with a certain
weight corresponding to the weight of the sinking sheet
encapsulating the bulk of material.
[0048] In one or more embodiments the sheet is made of a degradable
material. The choice of type of degradable material may be based on
when the bulk of material may be allowed to spread along the
seabed.
[0049] The degradable material may be a biodegradable material. The
biodegradable material may be a fiber based geotextile. The fiber
based geotextile may be made from coconut fibers or jute. A
geotextile made from coconut fibers or jute may be ideal for a
completely degradable sheet. The geotextile may be surface treated
in a water soluble biopolymer, ensuring that the geotextile
degrades after a few years.
[0050] In one or more embodiments the sheet is made of a permanent
material. The permanent material may be used if the encapsulated
material is to be used as building blocks. The permanent material
may be polypropylene and/or polyacetate.
[0051] The sheet may be made from the permanent material when the
encapsulated bulk of material is used as building blocks e.g. for
the use as the core or base of a dam, a quay, a bank reinforcement,
a jetty or a breakwater, for filling holes or trenches in the bed
of a waterway or the like.
[0052] In one or more embodiments the self-closing portion of the
sheet is made from a different material than the remaining sheet.
The material used for the self-closing portion my have a lower
strength than the material used for the remaining sheet, whereas
the remaining sheet includes at least the material containing
portion of the sheet.
[0053] In one or more embodiments the sheet may comprise an outer
sheet configured for being attached to the split barge such that
the sheet, as described above, constitute an inner sheet configured
for being in contact with the bulk of material.
[0054] The outer sheet may be configured for being in direct
contact with the split barge on one side and the inner sheet on the
other side and the inner sheet may be configured for being in
direct contact with the outer sheet on one side and the bulge of
material on the other side. I.e. the inner and outer sheet may be
arranged along an inside surface of the split barge. The surface of
the inner sheet being configured for being in contact with the
outer sheet may comprise a low friction surface, i.e. be
slibbery.
[0055] The outer sheet may be attached to the split barge along an
edge or part of an edge of the outer sheet by means of one or more
wires attached to the split barge in one end and to the outer sheet
in the other end. The wire(s) may be hooked to the split barge
and/or to the outer sheet.
[0056] When using a sheet comprising the inner sheet and the outer
sheet the bulge of material may be placed on/upon both the inner
and the outer sheet in direct contact with the inner sheet. As the
split barge is opened, the bulge of material starts to settle into
the water beneath the split barge. At some point, determined by the
length of the one or more wire(s), the wire(s) is tightened,
causing the inner sheet to slide off the outer sheet. The inner
sheet continues sinking towards the sea bed while the outer sheet
will hang in the wire(s) and may be pulled back up into the split
barge.
[0057] The material containing portion of the inner sheet may be
configured for being folded, for example zig-zag folded, when being
placed in the split barge. Folding parts of the inner sheet
arranged along the inside surface of the split barge, may
facilitate a degree of extendibility of the inner sheet. The
provided excess material of the inner sheet may unfold during
immersion of the bulge of material. The unfolded excess material of
the inner sheet may provide an extendibility of the self closing
portion of the inner sheet.
[0058] The outer sheet may be configured to withstand the peak
forces in/on the sheet occurring when the bulge of material
squeezes through the split barge when being opened. The outer sheet
may be configured to protect the inner sheet from being teared up
by sharp or rough surfaces and/or edges or other irregularities
in/on the split barge. The outer sheet may be a TenCate.RTM. sheet
or the like. The inner sheet may be configured to withstand the
forces imposed on the sheet during descent toward the sea bed. The
inner sheet may thereby be made of a material having a lower
strength than when only using one sheet.
[0059] The cost of manufacturing the sheet is related to the
requirements on the material strength. The advantage of using a
sheet comprising the inner sheet and the outer sheet is that the
inner sheet, which may be configured for single use, may require a
relative low material strength and thereby have a relative low
manufacturing cost. The outer sheet requiring a higher material
strength and thereby a higher manufacturing cost may be
reusable.
[0060] Further disclosed herein is a method of encapsulating a bulk
of material by means of a sheet as described above, the method
comprising; arranging the sheet in or under the split barge,
filling the sheet or the split barge with the bulk of material,
opening the split barge so that the weight of the bulk of material
starts sinking the sheet towards the seabed, encapsulating the bulk
of material followed by leading the sheet into an assembly point by
means of the water pressure induced around the sinking sheet, and
engaging the self-closing of the self-closing portion.
[0061] The step of opening the split barge may hereby be done
before the sheet may be closed around the bulk of material and
optionally sealed.
[0062] If the sheet is mounted to the split barge with the mounting
element, the step of disengaging the mounting element may be done
between the steps of opening the split barge and encapsulating the
bulk of material.
[0063] In one or more embodiments, wherein the sheet comprises the
mechanical and/or chemical sealing, the method further comprises
engaging the mechanical and/or chemical sealing concurrently with
engaging the self-closing of the self-closing portion.
[0064] In one or more embodiments, wherein the sheet comprises the
outer sheet such that the sheet, as described above, constitute an
inner sheet, the method further comprises retrieving the outer
sheet to the split barge.
[0065] The outer sheet may be attached to the split barge along an
edge or part of an edge of the outer sheet by means of one or more
wires attached to the split barge in one end and to the outer sheet
in the other end. The wire(s) may be hooked to the split barge
and/or to the outer sheet.
[0066] The outer sheet may be retrieved by pulling the outer sheet
back into the split barge. The outer sheet may be retrieved to or
pulled back into the split barge before closing the split
barge.
[0067] Further disclosed herein is a method of encapsulating a bulk
of material by means of a sheet as described above, the method
comprising; arranging the sheet in the split barge, filling the
sheet with the bulk of material, encapsulating the bulk of
material, engaging the mechanical and/or chemical sealing, and
opening the split barge releasing the encapsulated bulk of material
which sinks towards the seabed.
[0068] If the sheet is mounted to the split barge with the mounting
element, the step of disengaging the mounting element may be done
between the steps of filling the sheet and encapsulating the bulk
of material.
[0069] This method may be particular useful when dumping on very
low depths where the self-closing effect may not have the right
conditions for working properly.
[0070] In one or more embodiments, wherein the sheet comprises the
outer sheet such that the sheet, as described above, constitute an
inner sheet, the method further comprises retrieving the outer
sheet to the split barge.
[0071] The outer sheet may be attached to the split barge along an
edge or part of an edge of the outer sheet by means of one or more
wires attached to the split barge in one end and to the outer sheet
in the other end. The wire(s) may be hooked to the split barge
and/or to the outer sheet.
[0072] The outer sheet may be retrieved by pulling the outer sheet
back into the split barge. The outer sheet may be retrieved to or
pulled back into the split barge before closing the split
barge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0073] Different embodiments of the invention will now be
described, by way of examples only, with reference to the
accompanying drawings, as follows;
[0074] FIG. 1 schematically shows a cross-sectional view of a sheet
according to the invention with a self-closing portion and working
by the self-closing concept;
[0075] FIG. 2 schematically shows a cross-sectional view of a sheet
according to the invention arranged on a split barge;
[0076] FIGS. 3A and 3B schematically show the disengagement of the
sheet from the split barge according to the invention, and
[0077] FIG. 4 schematically shows the use of different embodiments
for sealing the sheet according to the invention.
[0078] FIG. 5 schematically shows a cross-sectional view of a sheet
according to the invention comprising an inner sheet and an outer
sheet.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0079] FIG. 1 schematically shows a sheet 1 according to the
invention with a self-closing portion 22 and working by a
self-closing concept, whereas the self-closing concept works as
following:
[0080] First the sheet 1 is arranged on or in a split barge 100 and
a material containing portion 4 of sheet is filled with a bulk of
material 101. A centreline of the sheet may approximately follow a
centreline 106 of the split barge. A material free portion 3 of the
sheet is hold along the edge of the split barge by a support
element (not shown). In the presently illustrated embodiment and as
shown in FIG. 2 the material containing portion of the sheet is
arranged along an inside surface 103 of the split barge and the
material free portion is hold by a support element 102 along an
outside surface 104 of the split barge. Alternatively the sheet may
be arranged along an outside surface of the split barge. The
material free portion 3 may be zig-zag folded.
[0081] Then the split barge 100 is opened and the weight of the
bulk of material 101 pushes the sheet 1 into the water. As the
sheet and bulk of material sinks towards the seabed the water
pressure around the sheet encapsulates the bulk of material forms
an encapsulated body 20 and collects the material free portion 3
into a tale following the sinking encapsulated bulk of material. In
the presently illustrated embodiment the tale starts at an assembly
point 21 and extends toward the water surface, whereas the tale
constitutes a self-closing portion 22 extending from the assembly
point an away from the encapsulated body.
[0082] As the encapsulated body 20 may shift into different forms
during immersion the assembly point may shift and a closing length
of the self-closing portion may vary during immersion. Furthermore
may the closing length, i.e. the length of the self-closing portion
from the assembly point to the edge of at least one of the opposite
sides of the sheet, and hereby the formation of the assembly point
of at least two opposite sides of the sheet likewise depend on the
density of the bulk of material as well as the volume of the bulk
of material, as the split barge may not be properly filled or even
only half filled when the split barge is opened and the bulk of
material is released entailing a longer closing length.
[0083] FIGS. 3A and 3B schematically show the disengagement of the
sheet 1 from the split barge 100 according to the invention. In the
presently illustrated embodiment the mounting element 5 comprises a
magnet arranged on the edge 2 of the material free portion 3 of the
sheet.
[0084] After the split barge 100 has been opened and the sheet 1
and the bulk of material (not shown) sinks towards the seabed the
sheet may as in the presently illustrated embodiment be dragged
along the inside surface of the split barge, see FIG. 1,
disengaging the mounting element 5 when the sheet is fully
outstretched.
[0085] The mounting element 5 may engage directly with the split
barge 100 or with a corresponding mounting element 105 arranged on
the split barge or on the support element 102.
[0086] FIG. 4 schematically shows the use of different embodiments
for sealing the sheet 1 according to the invention.
[0087] The sheet may comprise a mechanical sealing 10 or a chemical
sealing in at least the self-closing portion 22 of the sheet. In
the presently illustrated embodiment it is shown how the sheet can
comprise a hook and loop fastener 11 and/or a mushroom fastener 12
on the inside surface 103 of the sheet.
[0088] FIG. 5 schematically shows the sheet 1 according to the
invention comprising an outer sheet 1a wherein the sheet 1
constitutes an inner sheet 1b. In the presently illustrated
embodiment the outer sheet and the material containing portion 4 of
the inner sheet are arranged along the inside surface 103 of the
split barge 100 and the material free portion 3 of the inner sheet
is hold by a support element (not shown) along the outside surface
104 of the split barge. The material free portion 3 may be zig-zag
folded. Alternatively the outer sheet and/or the inner sheet may be
arranged along the outside surface of the split barge. One or more
wires 30 (illustrated by the stippled line) are attached to the
split barge in one end and the outer sheet in the other end.
[0089] The self-closing concept works as described above with the
addition of that when the split barge 100 is opened and the weight
of the bulk of material 101 pushes the outer sheet 1a and the inner
sheet 1b into the water, the wire(s) 30 is tightened, causing the
inner sheet to slide off the outer sheet. The inner sheet continues
sinking towards the sea bed while the outer sheet will be hanging
in the wire(s) until outer sheet is pulled back up onto the split
barge. As the inner sheet 1b and bulk of material 101 sinks towards
the seabed the water pressure around the sheet encapsulates the
bulk of material forming an encapsulated body (not shown) and
collects the material free portion 3 into a tale following the
sinking encapsulated bulk of material.
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