WO1997029247A1

WO1997029247A1 - Flexible container

Info

Publication number: WO1997029247A1
Application number: PCT/NL1997/000044
Authority: WO
Inventors: Anton Daniël KEMPERS
Original assignee: Ten Cate Nicolon B.V.
Priority date: 1996-02-08
Filing date: 1997-02-10
Publication date: 1997-08-14
Also published as: NL1002278C2; AU1675097A

Abstract

The invention relates to a flexible container consisting particularly of a textile fabric, for receiving loose or lightly cohesive material such as sand or other ground material via a closable filling opening, in order to form a bulk for deposition at a selected place, for instance for use as core or base of dam, a quay, a bank reinforcement, jetty or breakwater, for filling holes or trenches, for instance in the bed of a waterway, or for packaging and storing contaminated material, which container has at least one part with increased permeability, particularly to air. The container (10) according to the invention is characterized by a plurality of openings (102) which are distributed over substantially the whole container and which are each covered with a covering comprising a layer of gauze, which covering (103) is joined by means of connecting means to the whole peripheral zone of the hole (102), for instance by means of at least one stitched seam (104, 105, 106).

Description

FLEXIBLE CONTAINER

The invention relates to a flexible container, consisting particularly of a textile fabric, for receiving loose or lightly cohesive material such as sand or other ground material via a closable filling opening, in order to form a bulk for deposition at a selected place, for instance for use as core or base of a dam, a quay, a bank reinforcement, jetty or breakwater, for filling holes or trenches, for instance in the bed of a waterway, or for packaging and storing contaminated material, which container has at least one part with increased permeability, particularly to air. Such a container is known from the international patent application WO-A-88/03583 in the name of the present applicant. After a container according to this prior art has been filled, for instance in a floating tank, and subsequently closed, it is then deposited either by means of control means or in uncontrolled manner at a predetermined position, for instance at a depth of 4010 metres below a water surface. Particularly in the case where deposition takes place in more or less uncontrolled manner, it is often found in practice that due to air inclusion in the container the container the latter may undergo considerable change of shape during the sinking movement through the water, partly as a result of the upward forces exerted by the accumulated air.

It is an object of the invention to embody a flexible container of the described type such that particularly during sinking of a filled container the air accumulated therein during filling and closing can escape quickly in that it is driven out by water.

In this respect the container according to the invention is characterized by a plurality of openings which are distributed over substantially the whole container and which are each covered with a covering compromising a layer of gauze, which covering is joined by means of connecting means to the whole peripheral zone of a respective opening, for instance by means of at least one stitched seam.

The dimensions and mutual distances of the mutual holes depend on various parameters. These could include the dimensions of the container, the nature of the solid material and the air permeability of the coverings of the holes. When relatively finely distributed solid material is used, the relevant covering must, as will be apparent, be able to allow through air and water while retaining the material in the container. In such a case the total effective surface of the holes will possibly have to be chosen larger than in the case of coarser filling material.

Containers of the present type are generally very large and after fulling often contain many thousands of kilograms of material. The textile fabric is therefore manufactured from very tensively strong and wear- resistant structures. In this respect it is strongly recommended according to the invention that the covering and the connecting means have a tensile strength in the same order of magnitude as the textile fabric. In order to be able to absorb the outward directed force as reliable as possible during sinking of a container, the embodiment is recommended in which the covering is arranged on the inner surface of the container. A preferred embodiment of the invention has the special feature that the tensile strength of the textile fabric lies in the range of approximately 90-200 kN/m in each of the two principal directions. It should be understood that the length dimension extends in transverse direction of the tensile forces in question. The container preferably has the feature that the container is closable by a stitched seams with a tensile strength in the main plane of (80 + 10)% of the tensile strength of the fabric. This requirement can be met in different ways. A larger number of stitched seams can for instance be applied. Stronger yarns can also be used. Additional coupling/connecting and/or adhering means can further be used. It must be appreciated that a container, once closed and sunk, is placed permanently in position and does not have to be opened.

A variant has the special feature that the container is elongate and comprises a filling opening which extends in lengthwise direction and has two edges for mutually coupling by means of coupling means, which coupling means comprise a zip fastener with a tear-open strength of at least 100 kN/m, for instance a zip fastener of the YKK type which is connected to the textile fabric by means of stitched seams of extremely tensively strong yarn, for instance HMPE (Highly Modified Polyethylene) such as Dyneema (trademark of the Dutch company DSM) .

In the case where the force with which the container falls onto the bed is so great that there is the danger of the container rupturing, use can be made of a variant in which the container is provided with a plurality of yieldable expansion gussets placed in series with each other in the direction of the tensile force in the textile fabric. Such a "serial connection" of yieldable expansion gussets is capable of absorbing the forces in the textile fabric resulting from deforming of the container under influence of the severe shock forces in the relatively heavy solid fulling material. On at least partial failure of a gusset there results an extra margin in the length of the textile fabric (calculated in the direction of the forces) whereby the effective girth of the container is enlarged and the forces can be reduced to less damaging proportions. Such an expansion gusset can thus be regarded as a safety measure.

According to the invention, in the case where failure of one gusset is insufficient, a subsequent gusset can compensate the still remaining shock forces by failing. In order to prevent more or less uncontrolled failure of gussets, the expansion gussets can have different yield strengths.

A preferred embodiment has the special feature that the textile fabric comprises predominantly monofilament yarns.

This latter embodiment is preferably formed such that the textile fabric consists substantially of PE (polyethylene) and/or PP (polypropylene) . A spectacular extension of the effective lifespan of the container is realized with a variant in which the textile fabric consists substantially of PP with additives such that leaching is prevented and the effective lifespan under operating conditions is lengthened considerably, for instance from several decades to more than two hundred years.

The invention further provides a method for filling a container in accordance with the above stated specifications. Such a method is characterized by the following steps of: adding a quantity of water to the material for placing in the container such that it can be pumped as slurry,- and pumping the slurry into the container via the filling opening such that the water can leave the container via the textile fabric and the openings and the solid material is stored in the container.

The above described embodiment, in which the covering compromises two gauzes and a non-woven placed therebetween, is preferably embodied such that a gauze consisting of polyester is arranged on the outside of the container.

It is of general importance that, particularly in respect of the forces occurring during filling and sinking, the container is sufficiently strong to preserve its integrity. In this context it must also be deemed important that the tensile strength and the wear resistance of the whole container, including stitched and/or adhesive seams, the coverings of the holes, etc., have sufficiently high values.

The applied fabrics can be coated. Sufficiently strong structures should be used for the coverings of the holes . These can be based for instance on Nicolon/Miravi or Miragrid 20T. Suitable for use as yarns are reinforced polyester yarns which are embodied for instance as flat strips. The polyester gauze preferably arranged according to the invention on the outside of each covering designated as Geogrid.

The invention will now be elucidated with reference to a number of embodiments. Attention is drawn in this respect to the fact that figures 1-14 correspond with the figures in the already mentioned international patent application WO-A-88/03583. These figures therefore serve to elucidate the invention which will be further elucidated with reference to figures 15, 16 and 17.

Figure 1 shows a perspective view of a watergoing vessel with a tank which can be opened and closed, and a sheet to be placed therein,-

Figure 2 shows the vessel according to figure

1, in which the tank has been filled with bulk material;

Figure 3 shows the vessel according to figure

2, in which the sheet has been closed to form a bag; Figure 4 shows a transverse section through the vessel according to the preceding figures, in which is indicated the way in which the bag is sewn up,-

Figure 5 shows the aspect according to figure 4 in which the base is opened for the deposition of the bag filled with bulk material;

Figure 6 shows a schematic perspective view of a prefabricated container, with a zip fastener;

Figures 7a and 7b show, drawn in complementary form, variants with a number of expansion gussets; Figure 8 shows a partly cut-away perspective view of detail VIII of figure 7a;

Figure 9 shows a lashing connection for the closing of a container; Figure 10 shows a perspective view of a prefabricated container in a simpler embodiment;

Figure 11 shows a cross-section through a flat expansion gusset; Figure 12 shows a watergoing vessel with a sinkable split tank;

Figure 13 shows a watergoing vessel with a sinkable tilt tank;

Figure 14 shows a watergoing vessel embodied as a split tank with winch means for the lowering of a filled bag;

Figure 15 shows a partly broken away perspective view of a container according to the invention in an idealized, more or less schematic situation in which the filling is not shown,-

Figure 16 shows a partly broken away perspective view of the outside of the container, in which is drawn a through-hole with covering arranged thereon; Figure 17 shows a partly broken away perspective view corresponding with figure of a serial arrangement of yieldable expansion gussets.

Figure 1 shows a watergoing vessel 1 that comprises two floatable elongated parts 2, 3, arranged pivotably with respect to one another. The inner walls of these parts 2, 3 which are indicated by numerals 4, 5 form together a V-shape in cross-section, as can be seen particularly clearly in figure 4. In the closed situation according to figures 1 to 4, walls 4, 5 bound a closed tank. This is the one extreme situation. In another extreme situation, walls 4, 5 have been moved apart, as illustrated in figure 5. This situation will be described hereafter.

The floatable parts 2, 3 are pivotably connected together through hinges 6, 7. Means for opening and closing the tank bounded by walls 4, 5, are not depicted. These can be generally known, in particular hydraulic, means. As indicated schematically in figure 1, a sheet 9, represented in a strongly idealized way in figure l, can be placed into the tank 8 bounded by walls 4, 5. Sheet 9 is in this embodiment already formed into a prefabricated container, whose form is suited to the shape of tank 8, by means of sewn seams 10. A relatively small flap 11 project a short way from three sides of the sheet, while a large flap 12 extends from one side of the sheet. The manner in which sheet 9 is placed into the tank will be evident. This is indicated by an arrow 13.

In the situation according to figure 2, sheet 9 has been placed in tank 8 and completely filled with bulk material. The way in which this has taken place is not depicted. To this end, for example, sand, spoil or other ground material can be dredged from the waterway and poured into tank 8 onto sheet 9.

After the desired filling depth has been reached, flap 12 is folded over following arrow 14 to pass over small flaps 11.

Figure 3 shows that the overlapping zones, which are all indicated by reference number 15, are sewn together so that a robust filled bag 16 is obtained.

Figure 4 shows, for the sake of clarity, the configuration of figure 3 again in cross-section. It is apparent that the bulk material 17 has filled the entire bag 16. A schematically indicated sewing machine 18 shows how the large flap 12 is sewn to the small flaps 11, which if necessary can be fastened to the edge of the tank to facilitate the execution.

When the working with sewing machine 18 has been completed, the filled bag 16 is ready to be deposited at the desired place. To that end the vessel l can be brought to a position above the desired place (an activity which can take place at the same time as the sewing) , and after the place concerned has been reached the pivotable parts 2, 3 can be moved apart from each other in the manner shown in figure 5 by the unshown, for instance hydraulic, means, whereby a funnel open at the bottom is formed, through which the filled bag 16 can be passed and deposited on the bed of the waterway. Figure 6 shows a perspective view of a prefabricated container 19, of which the form, analogous to that shown in figure 1, is suited to the shape of a tank to be used. At the top, at the one side of the container 19, a narrow longitudinal flap 20 extends, while on the other side a broad longitudinal flap 21 is present. This broad longitudinal flap 21 can be joined by means of zip fasteners 22, 23, 24 to the narrow longitudinal flap, and to the short sides of container 19, respectively.

Figures 7a and 7b show, respectively, containers 25 and 26, of which the general shape corresponds to container 19 according to figure 6. Container 25 according to figure 7a is also provided with expansion gussets, generally indicated by 27, which will be further discussed by reference to figure 8. Container 25 according to figure 7a is provided with expansion gussets at its end surfaces, and an expansion gusset 27 extending in the longitudinal direction of container 25 over an upper surface thereof. Container 26 according to figure 7b has an expansion gusset 27 extending in the transverse direction on the upper surface of container 26.

As already explained, the expansion gussets serve to accommodate forces which can arise when a deposited container comes to rest on the ground with a shock. It will be clear without further comment that the fabric of the container can thereby be subjected to a large tensile force.

Figure 8 shows with arrows 28 the direction of those tensile forces. Expansion gusset 27, which consists of two cloth parts 29 projecting from the principal surface of the cloth and laid over each other, is sewn through in two places as indicated by reference numbers 29 and 30. On exertion of tensile forces 28, sewn seam 42 will be loaded first. If the forces are so great that this seam fails, then there comes about an extra margin or length in the cloth of container 25 in the direction of tensile force 28, so that the forces are reduced. Should this not be sufficient, sewn seam 43 can also still fail. Practice indicates that through this double safety measure there is no longer any danger that a deposited container will fail.

Figure 9 shows a lashed connection 30. In opposing edges 31, 32, rows of holes 33 are present for the lashing together of those edges by means of ropes 34. To ensure a satisfactory seal at the place of lashed connection 30, there extends a flap 35 from edge 31, under the holes 33. This flap 35 is first laid on the bulk material, after which edge 32 is placed thereover; finally ropes 34 are applied to fix edges 31, 32 relative to each other.

Figure 10 shows a simpler container 36. This shows a less elegant adaptation of the form to a tank than the containers described above. However, container 36 according to figure 10 has the advantage that it can be made more cheaply but can nonetheless be of a high quality. In contrast to the previously described containers, container 36 does not have more or less triangular end surfaces for optimal suiting of the form to a tank. It is provided with a more or less slit-like opening 37, through which the material can be poured into container 36. At the place of this slit 37, the previously described joining means can be present in the form of a zip fastener or rows of holes for the closing of container 36.

In this embodiment air valves 38 consists of holes covered by relatively coarse-woven material 39. The size, positions and numbers of these air valves 38 can be chosen according to the wishes of the user. Moreover, attention is drawn to the fact that the previously described containers can also be equipped with similar air valves. Figure 11, finally, shows an expansion gusset 40. Unlike gusset 27, shown in particular in figure 8, gusset 40 is embodied in a flat form, which makes the gusset less vulnerable. Three layers of the material of the container concerned are laid upon the other, and are joined together with two stitched seams 40, 41, further entirely analogously to the embodiment according to figure 8.

The operation of the embodiment of figure 8 applies, mutatis mutandis, to that of figure 11: tensile force 28 can break stitched seams 40, 41, whereby a margin in the length of the container fabric results and the risk of failure is at least considerably reduced.

Figure 12 shows a watergoing vessel 51 that is embodied as a floatable frame with winching means 52. These winching means 52 support a frame 53 with base parts 54. Frame 53 compriseε two parts 56, 57, pivotable with respect to one another, supporting the respective base parts 54 and 55, which can be moved towards and away from each other by means of cylinders 58. Cylinders 58 are coupled through hoses 59 to unshown powering and control means.

Using vessel 51, the method according to the invention takes place as follows. First, sheet 9 is placed on base parts 54, 55 of frame 53, in the situation in which frame 53 is located in vessel 51. The bulk material is poured onto sheet 9, and when the desired filling depth has been achieved a filled bag is made ready entirely according to the manner shown in figures 1-4. After this has taken place, vessel 51 is navigated to the chosen place and frame 53 is lowered by appropriate operation of the winch means 52 onto the bed of the waterway at the desired position. Through operation of cylinders 58, base parts 54, 55 are moved apart, whereby bag 16 is deposited at the desired place. Figure 13 shows a variant of the embodiment according to figure 12. A vessel 60 is embodied in practically the same form as vessel 51 according to figure 12. However, in this embodiment the vessel 60 comprises, besides winching means 52, winching means 61 placed on one side, which extend approximately centrally above a tilting tank 62. After the placing of a sheet and the filling of a container with bulk material in the same way as described in connection with figure 12, tilting tank 62 is brought to the chosen place by means of winching means 61. Through the empowering of winching means 52, tank 62 is tilted, whereby the container (not shown in figure 13) is brought into its place or the desired place.

Finally, figure 14 shows a vessel 63 which possesses roughly the same construction as vessel 1 according to figures l, 2, 3, 4 and 5. Vessel 63 is however equipped with winching means 64, comprising winching shaft 66 driven by a motor 65 through a reduction gearbox. With this winching shaft cooperate at the other end to vessel 63. The coupling means are indicated by reference number 68. Before placing sheet 9 in tank 8, bands 67 are placed therein. The bulk material is then poured onto sheet 9, after which, after vessel 63 has arrived above the chosen place, parts 2, 3 are moved apart and filled bag 16 comes to rest on bands 67. Winching means 64 are then activated by empowerment of motor 65, whereby a steady sinking of container 16 takes place. After container 16 has reached the bed of the waterway, bands 67 are released by actuation of the coupling means, whereafter they can be wound up onto winch shaft 66 through a corresponding activation of winching means 64. After the closing of tank 8, the appropriate ends of bands 67 can be reconnected to the coupling means 68, after which the cycle can be repeated.

Attention is drawn to the fact that the sinking of a tank according to the embodiment of figures 12 and 13 can if desired take place by use of guiding means, such as guide rails coupled or capable of being coupled to the ship. Attention is also drawn to the fact that the invention is not restricted to the use of a floatable tank, corresponding to the above described example. Tanks that are transportable over land also fall within the scope of the invention.Figure 15 shows a container 101 according to the invention. In accordance with the teachings of the invention this container 101 is provided with a plurality of openings 102 which are distributed over the whole container and which are each covered by a covering 103, the structure of which can be seen clearly in figure 16. Covering 103 is connected to the whole peripheral zone 107 of opening 102 by means of three very strong stitched seams 104, 105, 106.

As figure 15 clearly shows, each covering 103 is arranged on the inside of container 101.

Figure 16 shows that each covering 103 has a layer of gauze 108 placed on the inside, a layer of polyester gauze 109 placed on the outside and a layer 110 consisting of a non-woven placed between the layers 108 and 109.

With reference to figure 12 it is noted for the sake of completeness that in order to clarify the structure according to the invention the filling of the container 101 is not shown. In addition, the shape of container 101 is presented in idealized manner and adapted to the shape of a tank of the type according to figures 1, 2, 3, 4, 5. It is further noted that the end surfaces 111, 112 are also provided with openings 102. It can never be ensured during the sinking that the whole container is jettisoned by the tank simultaneously over its entire length. There is therefore the possibility that in the situation shown in figure 5 the one end for instance of the container begins to sink sooner than the other end. The thereby resulting air displacement in the container must be compensated by the exit of air via the openings 102 in the relevant end wall.

Figure 17 shows that the wall 113, substantially consisting of textile fabric, of the container 101 in this case has locally four expansion gussets 114, 115, 116, 117. Reference is thus made in this respect to the description of figure 8. The expansion gussets 114-117 can advantageously have different yield strengths. Thus is achieved that under conditions of relatively great tensile forces 28 the weakest gusset fails first, possibly followed by the following gussets in sequence of increasing yield strength. The adhering zone 118 shown in figure 15 with which the cover 119 is joined to the rest of the container wall 113 is preferably embodied such that the associated stitched seam yarn has a strength in the order of 80% of the fabric strength. In this case the tensile strength is therefore expressed in N/m².

Claims

1. Flexible container, consisting particularly of a textile fabric, for receiving loose or lightly cohesive material such as sand or other ground material via a closable filing opening, in order to form a bulk for deposition at a selected place, for instance for use as core or base of a dam, a quay, a bank reinforcement, jetty or breakwater, for filling holes or trenches, for instance in the bed of a waterway, or for packaging and storing contaminated material, which container has at least one part with increased permeability, particularly to air, characterized by a plurality of openings which are distributed over substantially the whole container and which are each covered with a covering comprising a layer of gauze, which covering is joined by means of connecting means to the whole peripheral zone of a the respective opening, for instance by means of at least one stitched seam.

2. Container as claimed in claim 1, characterized in that the covering comprises two gauzes and a non- woven placed therebetween.

3 Container as claimed in claim 1, characterized in that the covering and the connecting means have a tensile strength in the same order of magnitude as the textile fabric.

4. Container as claimed in claim 1, characterized in that the covering is arranged on the inner surface of the container.

5. Container as claimed in claim 1, characterized in that the tensile strength of the textile fabric lies in the range of approximately 90-200 kN/m in each of the two principal directions.

6. Container as claimed in claim 1, characterized in that the container is closable by a stitched seam with a tensile strength in the main plane of (80 ± 10)% of the tensile strength of the fabric.

7. Container as claimed in claim 1, characterized in that the container is elongate and comprises a filling opening which extends in lengthwise direction and has two edges for mutually coupling by means of coupling means, which coupling means comprise a zip fastener with a tear-open strength of at least 100 kN/m, for instace a zip fastener of the YKK type which is connected to the textile fabric by means of stitched seams of extremely tensively strong yarn, for instance HMPE (Highly Modified Polyethylene) such as Dyneema (trademark of the Dutch company DSM) /

8. Container as claimed in claim 1, characterized in that the container is provided with a plurality of yieldable expansion gussets placed in series with each other in the direction of the tensile force in the textile fabric.

9. Container as claimed in claim 8, characterized in that the expansion gussets have different yield strenghts.

10. Container as claimed in claim 1, characterized in that the textile fabric comprises predominantly monofilament yarns. ii. Container as claimed in claim 10, characterized in that the textile fabric consists substantially of PE (polyethylene) and/or PP (polypropylene) . 12. Container as claimed in claim 11, characterized in that the textile fabric consists substantially of PP with additives such that leaching is prevented and the effective lifespan under operating conditions is lengthened considerably, for instance from several decades to more than two hundred years.

13. Method for filling a container as claimed in any of the foregoing claims, characterized by adding a quantity of water to the material for placing in the container such that it can be pumped as slurry; and pumping the slurry into the container via the filling opening such that the water can leave the container via the textile fabric and the openings and the solid material is stored in the container.