FR2747383A1 - Floating absorber removes oil from water course - Google Patents

Abstract

Pollution is reduced in a liquid area by a floating device (100) comprising an hydrophobic material (130) which absorbs oil. This material is enclosed in a number of alveoli between sheets of material permeable by oil and water above (160) and below (150). The alveoli are sealed by joining, by heating the upper and lower sheets in the areas between alveoli.

Description

 The present invention relates to a device for cleaning up liquid areas and to a method for manufacturing such a device. The invention applies in particular to the depollution of water bodies and watercourses by absorption of pollutants.

 Certain bodies of water, such as pools bordering traffic lanes or bodies of water located in public places such as golf courses, are the site of indirect pollution due to the diffusion in the water from motor vehicle exhaust.

 Other areas, such as rivers or reservoirs, for example, can be the site of direct pollution due to the discharge of hydrocarbons or solvents from industry.

 In both cases, it is important to be able to have pollution control devices, installed as a preventive or curative measure, which make it possible to absorb the pollutants accumulated in the water as completely and as quickly as possible.

 At present, pollution control devices are generally used comprising a floating cover in the form of a cylinder, cushion or the like, said cover being filled with a polymer intended to absorb pollutants. Said polymer consists, for example, of polypropylene fibers. Reference may usefully be made to patent document FR-A-2 635 332 for the detailed description of such a device.

 A major drawback of devices of this type lies in the fact that their submerged part is relatively small, which limits the depollution substantially on the surface of the water. In addition, the rounded shape of these devices on said surface is such that absorption takes place essentially by capillary action, in particular in the usual case of a cylindrical cover. This results in a longer absorption time and lower efficiency.

 Another drawback of these devices is that they are very sensitive to variations in the wind, due to their negligible immersion.

 The object of the present invention is to provide a device for depolluting liquid areas comprising a cover intended to float on the area to be decontaminated, said cover containing an oleophilic and hydrophobic absorbent product, which has a satisfactory absorption surface allowing it remedy the aforementioned drawbacks.

 To this end, the depollution device according to the invention is characterized in that said cover is a sheet made up of two sheets secured to one another in superposition, one flat and the other comprising at least one row cells, each cell, made of a material permeable to water and to hydrocarbons and solvents, being provided to contain said product.

 According to another characteristic of the invention, each sheet has interstices, on the one hand, between each of its edges and the cells or panels adjacent to said edges and, on the other hand, between two adjacent cells or panels.

 According to another characteristic of the invention, the depollution device comprises a second ply identical to said ply, the flat sheets belonging respectively to said plies being fixed one on the other, the rows and the cells of a ply being respectively arranged in staggered rows with respect to the rows and cells of the other ply.

 According to another characteristic of the invention, the depollution device comprises at least a second ply, identical to said ply and connected to the latter by securing the respective longitudinal edges of said plies, so as to form a main ply including the cells belonging respectively to the rows adjacent to the joining line between the layers are staggered.

 According to another characteristic of the invention, the manufacturing method according to the invention of a pollution control device essentially consists in using two sheets, one flat and the other provided with cells at regular intervals, said cells being made up of a material permeable to water and to hydrocarbons, to fill the cells with an oleophilic and hydrophobic absorbent product and to weld the sheets to each other by adding heat, so as to obtain a sheet.

 According to another characteristic of the invention, the method of manufacturing according to the invention of a pollution control device consists in using two sheets identical to said sheet and in hot welding the flat sheets belonging respectively to said sheets one on the other, the rows and the cells of a ply being respectively staggered relative to the rows and the cells of the other ply.

 According to another characteristic of the invention, the method of manufacturing according to the invention of a pollution control device consists in using at least two plies identical to said ply and in connecting said plies together by hot welding of their respective longitudinal edges , so as to form a main ply, the cells of which are adjacent to the or each weld line between the plies are staggered.

The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an exemplary embodiment given by way of illustration and not limitation, said description being made in relation to the drawings seals, among which:
Fig. 1 is a side view of a pollution control device according to a first embodiment of the invention,
Fig. 2 is a front view of a pollution control device according to a second embodiment of the invention, and
Fig. 3 is a top view of a pollution control device according to a third embodiment of the invention.

 The pollution control device 100 shown in FIG. 1 consists of a rectangular rectangular floating sheet comprising on one of its faces two rows 110 and 120 of protuberances 111 and 121 (only the first protuberance 111, 121 of each row 110, 120 is shown). The sheet 100 is filled at regular intervals with an oleophilic and hydrophobic product 130 designed to be able to absorb polluting substances, such as hydrocarbons or solvents, said product 130 being housed at the location of the protuberances 111 and 121.

 The device 100 is for example positioned so that the direction of each row 110, 120 is perpendicular to the direction of the current of the area to be decontaminated, if it is a watercourse. This direction is indicated by an arrow A in FIG. 1. To this end, it is provided in each of its transverse edges 140 with means for hooking (not shown) to the banks of the watercourse, such as rings. These attachment means can also be used to hang two devices 100 between them.

 The sheet 100 consists of two sheets 150 and 160 which are welded to each other by adding heat.

 Each sheet 150 or 160 is made of a porous material permeable to water and to hydrocarbons, in particular. This material must also be such that it can be formed and welded without damage. It must therefore have satisfactory resistance to high temperatures. Said material is polyvinyl chloride or polyester, for example.

 One of these sheets 150, intended to constitute the lower part of the sheet 100 when it is launched, has cells 151 obtained by forming, which are identical and regularly spaced over several rows 110, 120, in number of two in this exemplary embodiment. However, one could also consider a number of rows 110, 120 greater than two. The cells 151, which for example have a substantially rectangular section, are designed to contain the absorbent product 130. In addition, the longitudinal side 151a of each cell 151 is perpendicular to the direction of each row 110, 120.

 The absorbent product 130 used is conventionally hydrophobic and highly oleophilic. Said product 130 is preferably made of polypropylene fibers. However, it could be made of another polymer.

 The other sheet 160, intended to constitute the upper part of the sheet 100 when it is launched, has a flat shape. It is intended to serve as a cover for the cells 151 of the first sheet 150. It will be noted that the sheet 160 is not necessarily made of the same material as the sheet 150. The sheets 150 and 160 can thus be made respectively of polyvinyl chloride and polyester, or vice versa.

 Following the hot welding of the sheets 150 and 160, there are respectively created interstices 152 and 163 on each of said sheets 150 and 160, said interstices 152 and 163 corresponding to the parts of sheets 150 and 160 welded to each other.

 There is shown in FIG. 1 the interstices 152 existing, on the one hand, between each edge 153 of the sheet 150 and the cells 151 adjacent to said edges 153 and, on the other hand, between two adjacent cells 151. As can be seen in Fig. 3 where two plies 300 'and 300 "are juxtaposed identical to the ply 100, the interstices 163 define between them panels 161 of shape coinciding with those of the cells 151, due to the weld mark. The panels 161 are separated from the edges 162 of sheet 160 by said interstices 163.

 The tablecloth 100 being placed flat on the area to be cleaned up, its protuberances 111 and 121 are entirely submerged, the flat face 160 of the tablecloth 100 being in turn substantially at the level of the water surface. Consequently, the contact between the polluting substances and the absorbent product 130 takes place over substantially the entire length, width and depth of each protuberance 151 containing said product 130, which substantially improves the absorption of said substances.

 In addition, the porous material used for the whole of the sheet 100 allows the runoff from above of said pollutants towards the core of the product 130, in the case where the polluted water has partially or completely covered the sheet 100 due to a strong current, for example.

 The device 100 according to the invention being largely submerged during the depollution operation, it is not very sensitive to wind. In addition, tests have shown that its particular structure allows it to respond quickly to any variations in current, thanks in particular to the interstices 152 and 163 separating the protrusions 151, into which the water infiltrates.

 It will also be noted that the sheet 100 does not modify the environment significantly, by virtue of its flat shape on the surface of the water. The depollution operation can therefore be carried out discreetly.

 The pollution control device 200 shown in FIG. 2 is made up of two plies 200 ′ and 200 "identical to that previously described, said plies 200 ′ and 200" being welded to each other by the addition of heat at their respective flat faces 260. Before welding, the plies 200 'and 200 "are superimposed as follows.

 For reasons of clarity, the interstices 152 and 163 corresponding respectively to the two sheets 150 and 160 of the sheet 100 of FIG. 1 were not represented. Let us call longitudinal interstice 210 (see Fig. 3) the interval between two rows 220 (only one is visible in Fig. 2) of a sheet 200 'or 200 ", and transverse interstice 230 the interval existing between two protrusions 240 of the same row 220. The device 200 is such that, on the one hand, each row 220 of one of the plies 200 'or 200 "is centered on a longitudinal gap 210 of the other ply 200" or 200 'and, on the other hand, each protrusion 240 of one of the plies 200' or 200 "is centered on a transverse gap 230 of the other ply 200" or 200 '.

Once put in the water, the device 200 is mostly submerged. This staggered configuration makes it possible for the pollutants which are found substantially vertically from each longitudinal 210 or transverse interstice 230 of the lower ply 200 ′, to be nevertheless absorbed by the active product contained in the protuberance 240 opposite the upper tablecloth 200 "Therefore,
Absorption is thereby improved overall, since the aforementioned interstices 210 and 230 do not constitute a limiting factor for the latter.

 The pollution control device 300 shown in FIG. 3 consists of two plies 300 'and 300 "identical to that of FIG. 1 which are secured to one another in juxtaposition. The two plies 300' and 300" are made integral with one another by their respective longitudinal edges 350 via welding, sewing or any other means, so that they define a main ply 300 having the same characteristics of flatness, on the surface of the water, and of protuberances (not shown), under water.

 The device 300 is such that each protuberance or panel 161 belonging to the row 320 of one of the plies 300 'or 300 "adjacent to the joining line 360 is centered on a transverse gap 330 of the other ply 300" or 300 '.

 Once the main ply 300 is put in the water, its protuberances are fully submerged, as in the first embodiment.

 This plan arrangement of two layers 300 ′ and 300 ″ makes it possible to further increase the contact time between the polluting materials entrained by a strong current, in particular, and the absorbent product contained in the protuberances.

 In addition, such an arrangement allows the device 300 to follow any waves or swell on the surface of the area to be decontaminated while remaining largely submerged, which makes it possible to continue to absorb the pollutants regardless of the direction of the current.

 As for the staggered arrangement, it is provided to allow the absorption of pollutants by the second sheet 300 "encountered in the direction of the current (arrow A), when said pollutants have not been in contact with the absorbent product contained in the first layer 300 'encountered. Indeed, a certain quantity of pollutants, entrained substantially vertically from a transverse gap 330 of said first layer 300', will cross said layer 300 'without coming into contact with the active product contained in However, this residue of pollutants will then enter the protrusion of said second ply 300 "which is adjacent to said transverse gap 330, hence its absorption.

 It should be noted that the three alternative embodiments which have just been described have in common an optimization of the contact surface between the polluting substances and the absorbent product and, consequently, an increase in the quantity of pollutant absorbed per unit of surface area of liquid and by volume of absorbent used.

 It will also be noted that the three devices 100, 200 and 300 described have good wind resistance and are oriented quickly as a function of the current, if any, due to their common structure.

 It will be understood that each sheet 100, 200 ', 200 ", 300' or 300" included in the depollution device 100, 200 or 300 according to the invention could comprise a different number of rows 110 and 120, 220, 320 of protuberances 111 , 121, 240, 340. In addition, all the rows 110 and 120, 220, 320 of the same sheet 100, 200 ', 200 ", 300' or 300" may not be arranged in an identical manner. Staggered arrangements, for example, are possible.

 In addition, the section of the protrusions 111, 121, 240, 340 is not necessarily rectangular. We could thus consider a polygonal section, for example.

 Finally, concerning the third variant embodiment of the invention, the device 300 could comprise n sheets 300 ′ or 300 "juxtaposed in staggered rows (with n> 2), the number n being chosen as a function of the strength of the current existing at the place pollution control and the quantity of pollutants, in particular.

Claims (7)

 1) depollution device (100, 200, 300) for liquid areas comprising a cover (150, 160) provided for floating on the area to be decontaminated, said cover (150, 160) containing an oleophilic absorbent product (130) and hydrophobic, characterized in that said cover (150, 160) is a sheet (100, 200 ', 200 ", 300', 300") consisting of two sheets (150 and 160) secured to one another in superposition , One plate (160) and the other (150) comprising at least one row (110, 120, 220, 320) of cells (151), each cell (151), made of a material permeable to l water and hydrocarbons and solvents, being provided to contain said product (130).  2) pollution control device (100, 200, 300) according to claim 1, characterized in that each sheet (150, 160) has interstices (152 or 163, 210, 230, 310, 330) on the one hand, between each of its edges (153, 162) and the cells (151) or panels (161) adjacent to said edges (153, 162) and, on the other hand, between two cells (151) or panels (161) adjacent.  3) pollution control device (200) according to one of claims 1 or 2, characterized in that it comprises a second ply (200 'or 200 ") identical to said ply (100), the flat sheets (260) respectively belonging to said tablecloths (200 'and 200 ") being fixed one on the other, the rows (220) and the cells (240) of a tablecloth (200' or 200") being respectively staggered relative to the rows ( 220) and to the cells (240) of the other sheet (200 'or 200 ").  4) pollution control device (300) according to claim 1, characterized in that it comprises at least a second ply (300 'or 300 "), identical to said ply (100) and connected thereto by securing the edges respective longitudinal (350) of said plies (300 'and 300 "), so as to form a main ply (300) whose cells (151) respectively belonging to the rows (320) adjacent to the joining line (360) between the plies (300 'and 300 ") are staggered.  5) Method for manufacturing a depollution device (100) for liquid areas, characterized in that it essentially consists in using two sheets (150 and 160), One plate (160) and the other (150) provided with cells (151) at regular intervals, said cells (151) being made of a material permeable to water and to hydrocarbons, to fill the cells ( 151) of an absorbent (130) oleophilic and hydrophobic product and of welding the sheets (150 and 160) to each other by adding heat, so as to obtain a sheet (100).  6) A method of manufacturing a pollution control device (200) according to claim 5, characterized in that it consists in using two plies (200 'and 200 ") identical to said ply (100) and in hot welding the flat sheets (260) belonging respectively to said plies (200 'and 200 ") one on the other, the rows (220) and the cells (240) of a ply (200' or 200") being respectively arranged in staggered with respect to the rows (220) and the cells (240) of the other ply (200 "or 200 ').  7) A method of manufacturing a pollution control device (300) according to claim 5, characterized in that it consists in using at least two plies (300 'and 300 ") identical to said ply (100) and connecting said plies (300 'and 300 ") to each other by hot welding of their respective longitudinal edges (350), so as to form a main ply (300) whose cells (151) adjacent to the or each weld line (360 ) between the sheets (300 'and 300 ") are staggered.