Classifications

• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/88—Dredgers; Soil-shifting machines mechanically-driven with arrangements acting by a sucking or forcing effect, e.g. suction dredgers
  • E02F3/90—Component parts, e.g. arrangement or adaptation of pumps
  • E02F3/92—Digging elements, e.g. suction heads
  • E02F3/9243—Passive suction heads with no mechanical cutting means
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/88—Dredgers; Soil-shifting machines mechanically-driven with arrangements acting by a sucking or forcing effect, e.g. suction dredgers
  • E02F3/90—Component parts, e.g. arrangement or adaptation of pumps
  • E02F3/92—Digging elements, e.g. suction heads
  • E02F3/9256—Active suction heads; Suction heads with cutting elements, i.e. the cutting elements are mounted within the housing of the suction head
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D11/00—Solvent extraction
  • B01D11/02—Solvent extraction of solids
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/26—Treatment of water, waste water, or sewage by extraction
• • E—FIXED CONSTRUCTIONS
  • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
  • E02F—DREDGING; SOIL-SHIFTING
  • E02F3/00—Dredgers; Soil-shifting machines
  • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
  • E02F3/88—Dredgers; Soil-shifting machines mechanically-driven with arrangements acting by a sucking or forcing effect, e.g. suction dredgers
  • E02F3/8858—Submerged units
  • E02F3/8866—Submerged units self propelled
• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62D—CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS
  • A62D3/00—Processes for making harmful chemical substances harmless or less harmful, by effecting a chemical change in the substances

Definitions

• the invention relates to the field of cleaning the bottom of liquid media, for example maritime or fluvial.
• the present invention finds particular application in the treatment and recovery of sediments is de nt u ntu re nd u nt and / or the fact of a pol l utio n su rles fon ds liquid environments such as estuaries, harbors, lakes, ponds, rivers, rivers or water retaining structures and treatment plants.
• dredging a cleaning of the funds of these environments.
• Classically, dredging operations are carried out periodically, for example every 3 to 5 years, to remove sludge or sediment that accumulates there and which can eventually disrupt human activities (societal , commercial, tourist, leisure, ...) and / or ecological balances.
• the equipment used often combines, on the one hand, a mechanical or hydraulic system making it possible to set in motion the sediments accumulated on the bottom to be cleaned, and on the other hand a system making it possible to extract the brewed sediments. usually a suction pump.
• a major disadvantage of these art systems is their negative impact on the aquatic environment. In fact, the sediments are stirred and lifted, and a part of them are distributed in the liquid space, giving a dirty and troubled appearance, then redepositing on the bottom.
• this brewing acts in depth, and can reach areas polluted by toxic, heavy metals or pesticides, from industries or urban waters. These toxins are generally trapped in layers of mud during sediment deposition on the bottoms of aqueous environments. However, most hydraulic or mechanical dredging systems remobilize polluted sediments from the cleaned area, exposing the previously buried toxins. These toxic sludge are thus in contact with the aquatic environment.
• the port (for example) is inaccessible or access is severely disrupted compared to normal use.
• Such dredging operations must also be regularly replicated (for example, every five years) since the siltation is continuous, which periodically disrupts the activities of the area concerned.
• the sediments following their extraction (and independently of the way this extraction is made), the sediments must be evacuated, and preferably at least partly reused and recovered. They are usually transported and then undergo pretreatment before use.
• This pretreatment aims on the one hand to separate the sludge particles from undesirable elements (detritus, ...) recovered during the dredging operation, and to dry the sediments by dissociating the dry matter of the water .
• pretreatment There are different types of pretreatment, the most commonly used being screening (ie the passage of sediments through a grid), sieving, (ie the passage of sediments to through a sieve) or draining (that is, natural drainage of sediments by migration of excess water).
• the present invention aims to overcome at least some of these disadvantages of the prior art.
• a sediment sampling system on a bottom of a liquid medium such as than a harbor or a pond.
• the system includes a duct whose lower end forms a movable suction mouth intended to be placed substantially at the bottom, and whose upper end opens out in the open air so that the mouth is under atmospheric pressure, the system comprising means for performing a local stirring, inside the mouth and means for evacuation connecting the mouth to the surface of the liquid medium, in which sediment circulates.
• Such a sampling system makes it possible to take small amounts of sediment from a silted soil and then extract it, reducing the environmental impacts on the aquatic environment.
• the means of carrying out a local stirring make it possible to detach the sediments from the bottom.
• Such agitation can be achieved by mechanical means (for example by means of stirring arms) or by means of generating an overpressure (for example by means of fluid jets).
• the fact that the pipe is under natural atmospheric pressure allows the creation of a local depression in its lower end, whose role is to contain the "contaminated" mixture of water and potentially polluted sediments within the zone of cleaning defined by the conduit lying on the bottom, without this mixture can be brought into contact with the external aquatic environment, as is often the case in current dredging solutions.
• the sampling system comprises a floating unit, supporting the evacuation means at a first end.
• one end of the duct is kept out of the water, in order to allow the evacuation of the mixing of water and sediments with adjacent barges or subsequent treatment operations, by means of evacuation means.
• the sampling system comprises a mobile unit on the bottom, connected to the evacuation means by a second end.
• This mobile unit on the bottom allows to clean silted areas difficult to access (such as areas under boats or pontoons for example), while leaving the waterways free, and maintaining the second end of the duct near the bottom so to extract the sediments removed by the evacuation means.
• the local stirring means deliver at least one jet of water under pressure directed towards the bottom.
• the means for carrying out a local stirring comprise at least one mechanical stirring device.
• It may for example be one or more propellers driven in rotation along a vertical axis, or tools mounted on a horizontal axis (for example similarly to a scarifier).
• the duct under atmospheric pressure carries and / or forms the evacuation means.
• Such a conduit allows both to protect and contain the evacuation means and to define a perimeter cleaning floor. Since the duct is at atmospheric pressure, a local depression is created within this cleaning perimeter when the level of the water and sediment mixture decreases as it is evacuated by the evacuation means. This local depression prevents any contact of the soiled liquid with the aquatic environment outside the conduit.
• this vertical duct can extend in one piece between the surface and the bottom.
• the mouth may be connected to this conduit, and more generally to the surface, by a flexible tube.
• the sampling system comprises proximity control means of the immersed height of the vertical duct.
• the position of the duct can thus be adjusted so that the submerged lower end of the duct rests on the floor to be cleaned.
• control means are motorized. This allows an automatic adjustment of the position of the conduit relative to the bottom, without manual action being necessary.
• the floating unit and / or the mobile unit on the bottom is equipped with autonomous displacement means.
• the system comprises means of control autonomous of its displacement, so as to progressively cover a predefined surface.
• the displacement means implement at least one guide cable, the control means driving at least one movable element along the cable or cables.
• the robotization of the sampling system avoids the need for human intervention to ensure and control its movement, which reduces the need for human and financial resources, and facilitates and speeds up the cleaning operations.
• the use of guide cables stowed at sea and / or on land is a simple and effective way to move the system.
• system is connected to at least one sampled sediment receiving unit.
• the sediments collected can thus easily be recovered, and if necessary be treated or recovered following their extraction.
• the invention also relates to a method of sampling sediments on a bottom of a liquid medium such as a port or a pond. Such a method comprises at least one iteration of the following steps:
• the steps are repeated, the successive placement steps being controlled by a step of locating the mouth.
• the location step takes into account a predetermined treatment plan, defining a surface to be treated progressively.
• each sequence of steps constitutes an automated cycle, allowing the cleaning to be done easily and progressively without external resources.
• the invention also relates to a device for pretreatment of sediments taken from a bottom of a liquid medium, comprising at least two successive sieving stages, each sieving stages comprising a sieving basket having meshes of predetermined size, rotatable within a receptacle, so as to separate filtrates, passing through said sieves meshes of said basket, and residues not passing through said meshes.
• At least one of the sieving stages comprises means for projecting a pressurized fluid onto at least a portion of the periphery of the sieving basket, from the outside to the inside thereof.
• the sieving basket has a frustoconical shape with an upper edge wider than the lower edge.
• the projection of fluid under pressure on the periphery of the basket makes it possible to unclog the meshes of the basket forming the filter.
• the pressure exerted by the fluid off the particles obstructing the filter, and puts them back in motion so that the sieving operation can be continued and the filtrates are evacuated.
• the specific shape of the basket allows the residual sediment to be ejected from the basket during its rotation, when the speed of the basket is increased.
• the projection means comprise a plurality of nozzles distributed over the height of the periphery.
• the basket is flared near its upper edge.
• This specific form again facilitates the ejection of residual sediment out of the basket, when the rotational speed thereof is increased.
• the shaft is mounted on an axis of rotation therethrough movable relative to the receptacle.
• the upper end of the axis of rotation is driven by a motor.
• the receptacle has an inclined bottom guiding the filtrates to transfer means.
• the filtrate transfer means comprise a discharge nozzle.
• the receptacle is fixed inside a tank receiving the residues.
• the tank has, under the receptacle, a funnel-shaped shape, guiding the residues towards disposal means.
• the sediment pre-treatment device comprises control means controlling the setting in rotation and / or the speed of rotation of said baskets and / or the distribution of said fluid under pressure.
• the sediment treatment cycle can be completely automated to gain performance.
• the sediment pre-treatment device comprises three successive sieving stages.
• the incoming sediments thus undergo three successive treatments, the size of the meshes of the sieving baskets reducing gradually as the stages of sieving. In this way, three types of residues can be recovered and recovered, the "ultimate” residues taking the form of very fine particles.
• the "ultimate” filtrates, evacuated at the end of operations are liquid and can be discharged directly into the starting environment. The device is thus efficient, since there is no "ultimate" waste to be stored.
• the pretreatment operations can be carried out "in situ" on the actual site of extraction of the sediments, unlike the solutions of the prior art that require transport of the sediments to a treatment zone. This makes it possible to considerably reduce the carbon footprint of transport operations since only the sediments released from their water (and possibly packaged) are transported.
• the invention also relates to a pretreatment stage for a device for sieving sediments taken from a bottom of a liquid medium, comprising a screening basket having meshes of predetermined size, which can be rotated inside a receptacle, so as to separate filtrates, passing through the mesh of the basket, and residues not passing through the mesh, comprising means for projecting a fluid under pressure on at least a portion of the periphery of the sieve pan, the outside towards the inside of it.
• the screening basket has a truncated shape with an upper edge wider than the lower edge.
• the invention also relates to a method for the pretreatment of sediments taken from a bottom of a liquid medium, comprising at least two successive sieving phases.
• each of the sieving phases implements operations of:
• Such a method allows efficient and simple sorting and dewatering of the sediments.
• FIG. 1 represents an example of a sampling system according to the invention, seen from the side;
• Figure 2 shows the sampling system of Figure 1, seen from above;
• Figure 3 is a bottom view of the sampling system of Figure 1;
• Figure 4 illustrates a first embodiment of the means for performing agitation in the lower end of the conduit
• FIG. 5 represents a second embodiment of the means of carrying out agitation in the lower end of the duct
• FIG. 6 illustrates an alternative embodiment of a sampling system, implementing an underwater unit
• FIGS. 7A to 7D show four embodiments of the sampling system
• Figure 8 illustrates the iterative steps of the sediment sampling process associated with the sediment sampling system
• Figure 9 shows a three-dimensional view of the sieving device according to the invention
• Figure 10 shows the holding structure of the sieving device according to a first embodiment
• Figure 11 shows the sieving device according to a particular embodiment
• Figure 12 shows a sectional view of a sieving stage according to this particular embodiment
• Figure 13 is a three-dimensional view of a screening basket and the associated high pressure cleaning system
• Figure 14 shows a variant of the high pressure cleaning system
• FIG. 15 illustrates an exemplary implementation method according to the invention
• Figure 16 is a view of the sampling system discharging sediment into the sieving device.
• the invention relates to the treatment of sediments accumulated on the bottom of liquid environments such as ports or ponds.
• Two aspects of the treatment are described which can be implemented in a single processing set (as illustrated in Figure 16). These two aspects are hereinafter described independently on board, and may if necessary be implemented independently of one another.
• the sampling is carried out using a floating unit ( ⁇ 5.1.1 and ⁇ 5.2), whose extraction you 52 delivers the sediment taken from the bottom.
• this extraction tube 52 directly feeds a device 100 for pretreatment of the sediments ( ⁇ 5.1.2 and ⁇ 5.3), installed for example on a quay Q or a bank.
• the pretreatment device can be embedded on the floating unit 20, or on a dedicated floating unit placed nearby.
• An independent implementation (sediments being stored in the meantime) can also be planned.
• another pretreatment is implemented. In the same way, the pretreatment can be applied also to sediments obtained by another type of sampling.
• Such a system comprises in particular:
• a suction mouth mo bile under atmospheric pressure, desti to be placated substantially at the bottom, means for performing a local stirring at the bottom, inside the mouth, to ensure, where appropriate, the detachment and agitation (or mixing) of sediments, and
• These means may extend inside an open conduit at both ends thereof, such conduit being supported by at least one floating element maintaining it partially emerged.
• the lower end of the duct constituted by the mouth, rigid, touches or touches the bottom, while its upper end is kept in the open air, at atmospheric pressure.
• the system of the invention comprises a surface unit, or floating unit, and / or a bottom unit, or immersed unit, which can be motorized and autonomously mobile, without human action required during cleaning, once an appropriate programming has been done.
• the sediments are removed, according to the technique described above or if appropriate according to another approach, they are routed to a sediment pre-treatment device comprising at least two successive stages (or a single stage in some cases).
• Such floors can for example be arranged in columns, steps or side by side. Sediment sieving allows gradual dewatering of sediments by dissociation of solid particles and liquid, sucked up during sediment sampling.
• Each of the sieving stages comprises a sieving basket having meshes of predetermined size, this basket being able to be rotated inside a receptacle, so as to separate filtrates, passing through the meshes of the basket, and residues, not going through the cracks.
• At least one of the sieving stages comprises means for projecting a fluid under pressure on the periphery of said sieving basket from the outside to the inside of the basket.
• the fluid projection means may comprise a single nozzle or a plurality of nozzles (for example aligned), delivering as many jets, over the entire height, or at least a large part thereof. They can be fixed or mobile relative to the receptacle and / or the basket.
• Figures 1, 2, 3 and 7A have a floating unit 20 supporting a conduit 30 mounted for example vertically, the upper end is held in a housing 21 provided for this purpose in the floating unit.
• the floating element is in the form of a rectangular barge of approximate dimensions of 2m x 1m, but can of course take any other aspect (circular buoy, boat ...) provided that the functions flotation and maintaining the upper end of the conduit 30 at atmospheric pressure are met.
• the shape of the duct and mouth may of course not be circular in section, but also, for example, of square, rectangular, oval or even any section.
• This duct 30 can be deployed vertically or not, provided that this rigid end rests on the floor to be cleaned.
• This conduit 30 envelopes on the one hand feed means 40 for directing one (or more) jet (s) under pressure, the water being pumped to the surface by a high pressure pump 44, and propelled to the bottom of the conduit 30 by the conduit (s) 43.
• Mechanical stirring means may also be implemented in another embodiment, as shown in FIG. 5, to ensure that the sediment is decolored and agitated.
• means similar to a scarifier 53 and / or a rotated propeller may be used.
• the stirring means generate a local stirring at the lower part of the conduit 30, where appropriate to take off sediments present on the bottom.
• This duct 30 also envelops an evacuation channel 50 to raise up to the surface a mixture of water and sediment.
• the supply means feed two jets of water under high pressure, guided in channels 43 and 41, 42 as visible in Figure 3. These channels extend within the conduit 30, their first end flush with the ground, their second end being connected to the channel 43 out of conduit, itself connected to a high pressure pump 44. Extraction of the sediment and water mixture is provided via the evacuation channel 50, which is extended above the surface by an extraction tube 52 which joins a sediment collection unit (not shown), for example in the form of a barge. A pump 51 propels the sediments brought to the surface by the extraction duct 52 itself in the duct 30.
• the duct 30 can be adjusted in height with respect to the floating element 20.
• a rack 61 fixed vertically on the outer surface of the duct 30 meshes with a toothed shaft driven in rotation by an engine.
• Means for controlling the position of the duct may allow the precise and automatic adjustment of the lower end of the duct relative to the ground.
• Figure 4 illustrates the lower end of the conduit 30 when a cleaning operation is in progress and that it rests on the ground.
• Displacement means for example four motors 70, 71, 72, 73, are fixed on the sides of the floating unit 20.
• four cables anchored at four securing points (for example on the bank) delimiting an area to be treated, are connected to the four motors: the actuation of the motors causes the winding of the cables or their unwinding, as required, and the displacement of the floating unit 20 along a path to four translation components.
• Automation means can be provided, so that the floating unit moves autonomously, and covers the entirety of a predefined surface, using mapping, positioning, avoidance means. obstacles, ...
• the displacement of the floating unit is managed by GPS geolocation ("Global Positioning System” in English) or the like. Geolocation makes it possible to identify and identify macro-waste and to ensure the traceability of the cleaning operations and the route taken.
• Means for picking up floating objects may be provided on the floating unit 20, for example to recover the invasive plants in the case of cutting operations.
• the sampling system can implement a bottom unit 80, moving on the bottom to be cleaned.
• This bottom unit 80 can move under the floating unit 20, or be able to shift relative to this floating unit 20, in particular to reach areas to be cleaned difficult to access (under boats or pontoons for example) or to leave waterways free.
• the bottom unit 80 has a housing 81 in which is mounted the rigid lower end of the conduit 30.
• This bottom unit 80 weighted to rest on the For example, the bottom (eg ballasts) takes a shape similar to the floating unit 20 holding the upper end of the conduit 30 out of the water.
• FIG. 7C illustrates an underwater unit 80 connected to a fixed unit 200 placed at the edge of a quay Q for example, by means of a flexible duct.
• FIG. 7D shows a bottom unit 80 and a floating unit 20 which can be offset relative to one another by means of such a flexible duct.
• Displacement means for example four motors 91, 92, 93, 94 (shown in FIG. 5) can be fixed on the bottom unit 80, in addition to or in place of those of the floating unit 20. D other means of displacement can be implemented, such as a crawler movement.
• This bottom unit 80 may, just like the floating unit 20, be controlled in an automated manner and its programmed displacement.
• Sediment deposition on the waterbed is the cause of siltation of spaces such as ports or ponds.
• the extraction of these sediments is, according to the invention, by means of the sampling system 10, comprising a floating unit 20 floated on the surface of a water point and then directed to an area to be cleaned by an operator , For example by towing or via a remote control, the motors 70, 71, 72, 73 located at the ends of the floating element 20 to easily orient the device 10 between the potential obstacles (boats, pontoons, ).
• the sampling device 10 can also be moved automatically. For this, it includes locating means (for example GPS geolocation) enabling it to work along a predefined path over a predefined sector. "Local” localization, using sensors distributed on the zone, is also possible.
• the motor 62 fixed on the floating element 20 is actuated, its toothed shaft meshing with the rack 61 fixed on the conduit 30.
• the position of the conduit 30 at depth is adjusted in height such that so that it comes touching the bottom to clean.
• Means for detecting the position of the duct 30 may allow, if necessary, an automatic adjustment of its lower end.
• the duct 30 is therefore placed under atmospheric pressure.
• the suction pump 44 is started and injects into the channel 43 a jet of high pressure water, then guided in the two channels 41, 42 to the ground.
• the pressure of the water jets on the mud layers makes it possible to detach the sediments from the soil and to mix them with the water present in the pipe 30.
• the depression generated by the extraction of the evacuation pump 51 ensures the suction of the mixture of sediment and water to the surface.
• the sediment and the water are then sent to a collection unit via the extraction tube 52, using the pump 51.
• the duct 30 remains under atmospheric pressure and delimits a restricted working perimeter on the ground makes it possible to eliminate the remobilization during the removal of the polluted sediments and avoids the contamination of the aquatic environment with the brewed toxic sludge.
• the suspended particles are in fact confined within the conduit 30, until they are sucked by the pump 52 and the corresponding area is cleaned.
• the duct 30 can then slide upwards via the height-regulating means 61, 62 so that it can be moved to another zone to be disengaged.
• this zone is close to that which has just been cleaned, and the cleaning is done gradually, in small areas (for example of 40 cm 2 and 1 m 2 ) successive.
• FIG. 8 An example of a method for collecting sediments from an aqueous bottom is illustrated in FIG. 8. It comprises, in this embodiment, nine main iterative steps, corresponding to the operating steps of the sediment sampling device, as presented in FIG. previous paragraph:
• a step 801 of moving the device to the area to be cleaned As the case may be, the floating part and / or the underwater part are displaced, so that the mouth is in line with the desired position;
• a sensor and / or sonar can allow precise control;
• the suction of the water by the pump 51 creates a vacuum in the zone of cleaning. It is desirable that the previous step 802 of descent of the conduit be completed before this step 803 begins, so that the cleaning perimeter (corresponding to the area defined by the mouth) is well defined and circumscribed; a step 804 for starting the stirring, for detaching the sludge from the bottom, by starting the pump 44.
• the start of stirring means (jets of water and / or mechanical means) begins a few moments after the start of the pump 51;
• This step 805 combines the effects of steps 803 and 804, ensuring the separation of sediments in a confined space and their evacuation. Steps 804 and 805 can also be performed at the same time. It is possible to vary the agitation and / or suction (stops, changes in speed, direction of rotation, power, ...), and moving the stirring means inside the mouth ;
• a step 809 for calculating a new position to be cleaned is preferentially automated, for example using a calculation rule determining a position to be reached, classically close to that which has just been processed, taking into account in particular the zones already treated, possible obstacles. , with a predefined treatment plan, an optimization of the journeys to be made, ....
• the device moves, or is moved, to the new zone (step 801), relaunching a new iteration of the nine steps.
• This sampling method of the invention thus makes it possible to collect the sediments continuously over time, without the need to resort to periodic and periodic dredging (for example every 5 years), and without interruption of the activity (especially for a port).
• the device may for example make it possible to treat between 1 m 3 and 2m 3 of sludge per hour, or between 8,000 m 3 and 16,000 m 3 of sludge per year, depending on the embodiments.
• the approach of the invention is thus opposed to the conventional approach, which provides for periodic cleaning, for a period of a few weeks during which the port, or the pond, can not be used in a normal manner.
• the cleaning extends over a long period of time, and may even be continuous: thus treating small quantities, permanently, without disturbing the activity of the port or the pond, and without strongly stirring the sludge and the sediments.
• the approach of the invention is particularly economical, and has the advantage that, the bottom being cleaned permanently, after 5 years, it is necessary to do only maintenance, which ensures the system of the invention, whereas, according to the prior art, the bottom is again completely silted.
• the sediments taken generally have a slow or slow appearance, including a liquid phase and a solid phase. They need to be dried in order to be stored or valued.
• Figures 9 and 10 show a sediment pre-treatment device 100 comprising three successive sieving stages 110, 120, 130.
• Each stage 110, 120, 130 pretreatment device 100 thus comprises three stages 11, 12,
• stage 13 forms a centrifuge system allowing gradual dewatering of sediments by sieving sediment particles smaller and smaller.
• the stages 110, 120, 130 are assembled in stairs in the embodiment illustrated in FIGS. 9 to 11, but could equally well be assembled in columns or side by side.
• the stages 110, 120, 130 may be fixed to a structure comprising one or more walls 140 and one or more roofs 150, forming a shelter, and intended to rest on the ground or on a barge.
• the wall 140 of this structure comprises in particular on its inner face protruding elements 141, 142, 143 now fixed each of the sieving stages relative to each other, and relative to the ground.
• Other holding structures can be envisaged as a perforated structure.
• FIG. 11 shows the stages 110, 120, 130 sieving the device according to a preferred embodiment.
• each floor comprises a hood closed tank, provided with a high pressure cleaning system, a discharge and a discharge pipe, as described more precisely to follow, in correspondence with Figure 12.
• a first screening stage 110 forming a first centrifuge system thus comprises a basket 300 provided with meshes on its surface, so as to form a filter allowing only a certain particle size.
• the basket 300 preferably has a frustoconical shape, the perimeter of its high edge being greater than the perimeter of its low edge, the basket 300 thus being flared in its high edge.
• the basket 300 is also provided with an ejector rim 310 in its upper part as illustrated in FIG. 5. The size of such a basket is in correspondence with the volumes of sediments to be extracted during an entire cycle.
• Such basket 300 may also have any other shape facilitating the drying and ejection of sediment.
• the basket has a nominal diameter in a dewatering phase, and a larger diameter in a sediment ejection phase. This can for example be provided by three sliding means at 120 ° in the upper part of the basket.
• This basket 300 is secured to an axis 400 adapted to be actuated in rotation by a motor M preferably electric.
• a motor M preferably electric.
• the base of the basket is advantageously mounted tight around the axis of rotation 400, but a mechanical connection by belt or reducer can also be considered.
• a receptacle 500 receives the screening basket 300, the lower end of the axis 400 being connected to the base 510 of the receptacle 500.
• the lower end of the axis 400 is provided with a base 410 comprising a ball bearing 420, and cooperates with a bearing support 520 emerging in the center of the base 510 of the receptacle 500.
• the receptacle 500 is mounted in a tank 600, which can take any type of shape (cylindrical, cubic, frustoconical ).
• the vessel has a substantially frustoconical shape, having under the receptacle 500, a funnel-shaped element for discharging residues.
• residues is meant the sediments deposited in the screening basket 300 and too large to cross the mesh of the basket.
• the tank 600 is provided with a cover 610 pierced at its center to receive the axis 400 which is secured to the screen basket 300.
• the motor M to turn this axis 400 and to activate the centrifugation process, is located at the upper end of the axis 400, and above the cover 610.
• the receptacle 500 is fixed by different points to the tank 600, the receptacle 500 and the tank 600 forming a fixed assembly.
• the residues that are too large to pass through the meshes of the basket 300 are ejected outside the basket 300 via the ejector flange 310 and fall into the tank 600, then are conveyed for gravity conditioning to the end 620.
• the residues may possibly then be recovered in a storage bin, as shown in Figures 9 and 10.
• the receptacle 500 is in connection with means for discharging the filtrates, which may, for example, take the form of a discharge nozzle 530 (or a tube, a channel, etc.) placed in the end the lowest of the receptacle.
• Filtrates are called the set of liquid and sedimentary particles, having crossed the mesh during the rotation of the basket 300.
• the receptacle 500 is also provided with means for projecting a fluid under pressure, which comprise in the embodiment described a channel 700 for conveying the fluid (preferably water, but possibly also oil or petrol). ) provided with a plurality of nozzles 710 over part of its height. These nozzles are shown in greater detail in FIGS. 13 and 14.
• the channel 700 is inserted inclined through the cover 610 of the tank 600 and the receptacle 500 so as to orient the fluid spray nozzles 710 perpendicular to the outer surface of the nozzle. basket 300 and over all its height. The nozzles 710 are thus positioned so as to brush against the outer surface of the basket 300.
• a single movable nozzle moves along the channel 700 in order to project the fluid between the bottom edge and the top edge of the channel.
• basket filter 300 In an alternative embodiment, shown in FIG. 14, blanks 710 are uncovered and respectively covered by a rotation of a shutter shell 720 around the channel 700, so as, on the one hand, to allow (and respectively prevent) the projection of the high pressure fluid arriving in the channel and also prevent the particles passing through the basket 300 during centrifugation to come to obstruct the nozzles.
• the rotation of the envelope may naturally be initiated by the rise in pressure of the channel.
• the means for projecting the fluid under pressure are not limited to the examples mentioned above.
• the sieving stage 110 is connected to the sieving stage 120 by the overflow nozzle 530 guiding the filtrates from the receptacle 500 to the next sieving basket.
• the various stages of the wetting 110, 120, 130 of the device 100 can also communicate with each other via a piping system comprising, in the case of a staircase assembly, tubes of Elbow evacuation 111, 121, 131. In the case of an installation in colon, these evacuation you would be straight. The sediments are thus discharged into the sieving basket 300 of the first stage 110 by means of a first evacuation tube 111.
• the tank 500 of the first stage 110 is open on a second exhaust pipe 121 which makes it possible to evacuate the filtrates.
• This 121 is oriented by an elbow towards the sieve basket of second stage of sieving 120.
• a third one 131 similarly discharges the filtrates from the second stage 120 to the third stage 130.
• a fourth tube 141 emerges from the tank of the last stage 130 and discharges the filtrates, which are Stage l iquids, towards a reservoir or in the environment of departure (port, lake, pond ).
• each of the stages 110, 120, 130 regardless of the embodiment, therefore has a similar structure, forming a centrifuge system. Only the size of the mesh of the sieving basket varies so that the filtering of the sediments is gradually refined as and when the stages are crossed. Thus, in the embodiment described, the first screening stage 110 retains the large particles larger than 5 mm, the second stage 120 filters the residues of average size, between 1 and 5 mm, and the third stage 130 treats small particles smaller than a millimeter in size.
• the residues can be ejected to a storage bin 112, 122, 132 corresponding, and recovered for recovery.
• large-scale waste pebbles, gravel
• medium-sized waste sand
• waste fine size valued in agronomy waste fine size valued in agronomy.
• Such a device 100 of sediment sieving can rest on the ground or be installed on a barge, on the surface of a liquid medium (harbor, pond, lake ...), this latter configuration allowing the sediments not to pass through a stage of "waste".
• the sediments, of pulverulent type, recovered during a dredging operation, for example, are automatically discharged inside the first screening basket 300 of the first stage 110.
• a sieving cycle comprises several phases, or steps, after the first stage sieve has received (step 810) a sediment dose to be treated:
• a first phase 810 of a duration appropriate to the desired drying, the electric motor M is actuated, driving in rotation the axis 400 which is secured to the basket 300.
• the rotation of the basket in the manner a centrifuge, increases the gravity field around the sediments: they are pressed against the hole surface of the basket 300, and water and particles smaller than the size of the holes are projected through the basket 300 and reach the receptacle 500 and the tip 530, preferably placed above a second sieve basket of the next sieving stage to undergo a second treatment, the second sieving basket having mesh size lower.
• a second phase 820 the rotation speed of the basket 300 is then increased so as to project the residues that have not passed through the holes along the inclined walls of the basket and towards the ejection edge 310 at the top of the basket.
• the residues due to the speed acquired during the rotation of the basket, are ejected in the tank 600 and join the funnel 620 for the purpose of being transferred and possibly stored in storage bins.
• a third phase 830 of rotation of the basket 300 slower is accompanied by the startup of the nozzles 710 for spraying fluid under pressure.
• the fluid is thus projected over the entire height of the basket 300, and because of its rotation over its entire periphery.
• the pressure exerted makes it possible to unclog the holes of the basket 300 by pushing the particles obstructing the filter towards the center of the basket.
• the following sieving operations do not lose in effectiveness.
• a fourth phase 840 the supply of the nozzles projection 710 cut off and the motor M is stopped, the rotation of the basket thus being stopped.
• a new sediment spill in the basket 300 can also be envisaged, which operates with a slow speed of rotation, so as not to completely stop the motor M.
• the cleaning fluid flowing in the receptacle 500 causes the remainder of sediment particles filtered to the tip 530, then to the second stage 120 sieving.
• Each sieving stage reproduces these same phases constituting a sieving cycle. All sieving stages can operate at the same time, only the filling of the highest basket is automatically performed before each rotation. Furthermore, the rotation of the baskets, the speed of rotation of the baskets and the distribution of the cleaning fluid are advantageously automated so as to make the sediment treatment operations more fluid and efficient.
• the ultimate filtrates are preferably substantially liquid and can be returned to the environment in which the sediments have been removed or transferred to a treatment zone, if polluted.

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• 2015
  • 2015-12-18 CA CA2971370A patent/CA2971370A1/fr not_active Abandoned
  • 2015-12-18 WO PCT/EP2015/080673 patent/WO2016097380A1/fr active Application Filing
  • 2015-12-18 CN CN201580076322.7A patent/CN107438689A/zh active Pending
  • 2015-12-18 EP EP15820126.9A patent/EP3234265A1/de not_active Withdrawn
  • 2015-12-18 US US15/537,048 patent/US10508413B2/en not_active Expired - Fee Related

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