FR2909371A1 - Mobile tank for streamline treatment of effluents e.g. sludge intended to be placed on ground, comprises detachable partition wall delimiting upper and lower compartment inside tank, and inlet conduit to get effluents to be treated - Google Patents

Abstract

The mobile tank for streamline treatment of effluents e.g. sludge intended to be placed on a ground, comprises a detachable partition wall (14) delimiting an upper and a lower compartment inside the tank, an inlet (4) conduit to get effluents to be treated in an upper part of the compartment so that the effluents are poured in a filtration bag (9), an unit to evacuate the effluents outside of the take by gravity, a detachable lid, a hook means for hanging the filtration bag, and a pump connected to the inlet for transferring the effluents to be treated in the tank. The mobile tank for streamline treatment of effluents e.g. sludge intended to be placed on a ground, comprises a detachable partition wall (14) delimiting an upper and a lower compartment inside the tank, an inlet (4) conduit to get effluents to be treated in an upper part of the compartment so that the effluents are poured in a filtration bag (9), an unit to evacuate the effluents outside of the take by gravity, a detachable lid, a hook means for hanging the filtration bag, and a pump connected to the inlet for transferring the effluents to be treated in the tank. The compartments are in fluid communication through a passage (15) of the partition wall. The upper compartment is equipped with the filtration bag, and the lower compartment is partially filled with a porous substrate containing zeolite. The evacuation unit (6) comprises an evacuation conduit equipped with a valve emerging in the lower compartment, where the conduit is disposed above and opposite to the passage of the partition wall. The partition wall is intended to support the filtration bag, and is supported by two vertical parallel walls laterally delimiting the lower compartment. The inlet conduit is carried by the lid.

Description

The present invention relates to a mobile treatment tank

  of effluents, in particular for the treatment of fairing effluents laden with sludge, suspended solids, hydrocarbons and / or heavy metals.

  Current standards prohibit discharge to the sea of effluents from boat refit operations. Boating professionals such as ports and shipyards, wanting to continue to practice the fairing activities that are part of the services offered to users, must therefore be equipped with systems for the recovery and treatment of wastewater effluents. To date, to carry out the fairing operations, the boats are out of the water by crane, or by means of a trailer of water outlet from a hold, to be brought on a fairing area allowing to gather the fairing effluents. This fairing area is associated with a specific treatment unit, at least partially buried, to which the recovered effluents are treated. Such a system is described in particular in patent document WO2004 / 080559. This patent document also describes specific fairing shims to continue to carry out the fairing operations directly on a hold during a tide, the fairing effluents recovered in the lower part of the hold are transferred to the processing unit. The treatment unit comprises a buried buffer tank, for recovering effluents from a fairing area and / or a fairing wedge, means for transferring the effluents from the buffer tank to an external settling tank provided with withdrawal means for recovering the sludge, and a buried filtration unit to which the effluents from the settling tank are conveyed. The establishment of such recovery and treatment systems, including such processing units, requires major structural work that some ports or shipyards can not perform for reasons of cost and / or location. . The object of the present invention is to provide a system overcoming the aforementioned drawbacks, and in particular a processing unit which is simple in design, easy to install and inexpensive. For this purpose, the present invention provides a treatment unit in the form of a single mobile vessel, transportable from one site to another, to be placed on the ground. The tank according to the invention thus makes it possible to carry out fairing operations in the ports which comply with the standards in force, without having to produce a specific stationary processing unit. The present invention therefore relates to an effluent treatment tank, in particular fairing effluent, intended to be placed on the ground, characterized in that it comprises a separating wall delimiting inside the an upper compartment and a lower compartment, said compartments being in fluid communication with at least one passage of said partition wall, said upper compartment being provided with at least one filter bag, and said lower compartment being at least partially filled with a substrate, inlet means capable of supplying effluents to be treated in the upper part of the upper compartment so that the effluents are discharged into the filter bag, and evacuation means capable of evacuating the effluents out of the tank by gravity, from the lower compartment after passing through the substrate. The tank according to the invention makes it possible both to decant the effluents in the filter bag, a filtration through the filter bag, the settling particles and the bag filtration particles being recovered in said filter bag, and a substrate filtration. The tank according to the invention thus ensures a simple and effective treatment of the effluents, in particular fairing effluents charged with various particles or suspended materials such as sand, anti-fouling paint particles and / or sanding dust, of hydrocarbons such as gasolines, motor oils and / or solvents. The vessel according to the invention will advantageously be used in combination with a fairing trailer as described in the patent application, filed on the same day and with the same name as the present, entitled Fairing Trailer and Recovery and Treatment System. process, to form a complete system for the recovery and treatment of the fairing effluents, which can be easily moved from one site to another, the treatment tank being arranged on the trailer for its transport of a site to the other, and placed on the ground and then connected to the effluent recovery means of the 2909371 4 trailer for the transfer of recovered effluent to the tank. According to a particular feature, the evacuation means comprise at least one evacuation duct equipped with a valve, opening into said lower compartment, preferably at a free zone devoid of a substrate, said duct being disposed above said passage of the partition wall to ensure a minimum level of effluents in the tank and to prevent the passage of floats, in particular hydrocarbon type, through the substrate, and / or disposed opposite said passage of the wall separation device for optimizing the passage time of the effluents through said substrate, said passage being advantageously formed between the side wall of the vessel and an edge of the partition wall. According to another feature, said partition wall is adapted to support the filter bag. In one embodiment, the partition wall is supported by at least two parallel vertical walls which laterally delimit said lower compartment. Advantageously, said partition wall is at least partially removable to facilitate control and replacement of the substrate.

According to another particularity, the tank comprises a removable cover for allowing the removal of the filter bag and its replacement, the cover being preferably equipped with ventilation vents, one or more lifting rings and / or a access hatch. According to one embodiment, said intake means comprise at least one intake pipe carried by said cover.

Advantageously, the tank comprises hooking means for hanging a filter bag by its upper edge. According to one feature, the tank is equipped with a pump connected to said inlet means for the transfer of effluent to be treated in the tank. According to one embodiment, the lower compartment is at least partially filled with a porous substrate based on zeolites.

The invention will be better understood, and other objects, details, features and advantages will become more clearly apparent from the following detailed explanatory description of a particular presently preferred embodiment, with reference to the accompanying schematic drawings, in which: - Figure 1 shows a schematic sectional view of a treatment tank according to the invention: _on, with its upper compartment equipped with a filter bag and its lower compartment filled with substrate; FIG. 2 is a diagrammatic sectional view of a tank according to an alternative embodiment, before the introduction of the filter bag and the substrate; FIG. 3 is a view from above of the tank of FIG. 2, in the absence of the cover and the separation wall, and FIG. 4 is a view similar to FIG. 4, with the partition wall. set up. FIG. 1 represents a treatment tank 1 according to the invention intended in particular for the treatment of fairing effluents. The tank comprises a bottom wall 11, through which the tank is intended to be placed substantially horizontally on the ground, a vertical side wall 12, and a removable cover 13 resting substantially horizontally on the upper edge of the side wall. According to one embodiment, the tank has a generally cylindrical shape of vertical axis A, with a cylindrical side wall 12. The interior volume of the tank is divided vertically by a partition wall 14 into two superimposed compartments: an upper compartment C1, 10 called settling and bag filtration, and a lower compartment C2, said filtration on a substrate. The partition wall extends over most of the cross section of the vessel, the two compartments communicating through a passageway defined between the sidewall of the vessel and an end edge of the partition wall. The partition wall extends substantially horizontally, perpendicular to the axis of the tank, with a slight slope in the direction of the passage 15.

The upper compartment is equipped with a filter bag, shown schematically in broken lines under the reference 9, for example a 5 micron filter bag, for recovering the settling particles, filtering the effluent and recovering the effluent. 25 fine particles of filtration. The tank is equipped in the upper part with several hooks 3 fixed at regular angular space on the side wall for the reversible hooking of the bag by its upper edge and its holding in the open position. In the embodiment of FIG. 1, the bag is held suspended above the partition wall.

An intake pipe 4 is disposed in the upper part of the tank, for the introduction of effluents to be treated in the tank. The pipe is for example assembled on the inner face of the lid 13. When the tank is closed by the lid, the pipe passes through the side wall and extends radially above the filter bag, from the side wall to the center of the tank. tank. The end of this pipe is advantageously equipped with a bend to direct the effluent streams downwards into the filter bag. The conduit is housed in a notch of the cylindrical wall, or may be sealingly connected to a fitting passing through the side wall. The tank is advantageously equipped with a pump 15 for transferring the effluents from a storage system and / or collection of effluents to be treated to the treatment tank. The pump is externally joined to the sidewall 12 and includes a suction line 51 for connection to the storage and / or collection system, and a delivery line 52 connected to the aforesaid intake line. The lower compartment is filled with a substrate shown schematically under the reference S. The substrate is formed of porous granules, for example based on zeolites, ensuring by adsorption and ion exchange the elimination of dissolved particles, for example less than 5 microns, hydrocarbons, ammonium ions, and / or heavy metals. The porous structure of the substrate provides, by molecular sieve effect, a high adsorption capacity of organic and inorganic elements.

2909371 8 A discharge pipe 6, equipped with a valve 61, is mounted on the cylindrical wall, opposite the passage for discharging the effluents out of the tank. A vertical grid 7 is disposed in the lower compartment 5 to retain the substrate and keep in the lower compartment a free zone 8, devoid of substrate, on which opens the discharge pipe 6. The passage 15 and this free zone 8 extend over opposite annular sectors, for example between 10 and 60. As can be seen in FIG. 1, a vertical retaining wall 16 extends downwards from the partition wall and has a lower edge disposed at a distance from the bottom wall 11, the aforementioned vertical grid 7 being arranged at the level of the passage defined between the bottom wall and the lower edge of the vertical wall. The separation wall has at this free zone 8 a recess 14a upwards, the discharge pipe opening at this recess, above the passage 15. This arrangement 20 ensures a minimum level in the tank avoiding the passage hydrocarbon floaters through the substrate. The lid is equipped with ventilation vents 18 allowing the ventilation of the upper compartment C1, and in particular the oxygenation of bacteria placed in said upper compartment in the case of the removal of the floating layer by bacterial treatment. The cover advantageously comprises one or more lifting rings 19 to facilitate its installation and removal. An access ladder (not shown) is advantageously provided along the side wall to facilitate access to the top of the tank, and in particular to an access hatch of the cover, in order to monitor the Floats and sludge level in the filter bag, set up or replace adsorbent breads and / or bacteria culture medium. In order to obtain a tank as light as possible and thus facilitate its handling, the tank is advantageously made of a plastic material, such as HDPE, or a composite material based on resin and fibers, such as a material of polyester type reinforced with glass fibers. The operation of the tank will now be described. After connecting the suction line 51 of the pump 5 to a network of channels of a fairing area, 15 to a storage tank and / or a fairing trailer, the fairing water is pumped and introduced into the tank. filter bag through the inlet duct ... After filling the tank, settleable particles and suspended solids of large particle size accumulate in the bottom of the bag by static decantation. Due to their low density, hydrocarbons float upwards. After settling, for example over a period of about 10 hours, and connection of the discharge pipe 6 to a wastewater network 25, the discharge valve 61 is open. The settled effluent passes through the wall of the filter bag by gravity and then the substrate. The arrows in FIG. 1 schematically illustrate the flow of effluent into the tank at the opening of the valve. The flow rate will be controlled, for example from 1 to 2 m 3 / h to obtain an optimal reduction of heavy metals through the substrate. Keeping the tank water at a minimum level allows the floating layer to be removed at any time by absorbent systems and / or bacterial treatment. The tank according to the invention thus makes it possible, after each filling, to decant the effluents to capture a large part of the suspended matter, a separation of the hydrocarbons by flotation, a bag filtration to complete the preliminary decantation and recover the finer particles, for example greater than 5 microns, and substrate filtration for the removal of dissolved particles such as heavy metals, microparticles of paints, pesticides, etc. The filter bag will be regularly removed to extract the sludge B, and to control the substrate and possibly replace it, after removal of the partition wall. For example, the filter bag will be emptied once a year and the substrate replaced every two years. Figures 2, 3 and 4 illustrate a tank 101 according to an alternative embodiment, in which the filter bag 20 rests on the partition wall 114. To do this the partition wall is reinforced to support the weight of sludge accumulated in the bag . It is in the form of a generally circular plate, placed on the upper edge of vertical walls 25 which extend upwards from the bottom wall 111, parallel to each other. The tank comprises two main vertical walls 120 disposed on either side of the axis A 'of the tank, and two so-called secondary vertical walls 121, also disposed symmetrically on either side of the axis, beyond main vertical walls. The lower compartment C'2 is delimited in height by the separation wall 114, and laterally by the two main vertical walls 120. A gate 107 is disposed transversely between the two main vertical walls 120 to define as previously a free zone 5 108. The partition wall includes a removable portion for accessing the lower compartment to facilitate placement and replacement of the substrate. With reference to FIG. 4, the partition wall has a generally rectangular aperture 114b extending substantially from a main vertical wall 120 to the other, and from the grid 107 to the side wall 112 of the vessel. A removable portion 1141 in the form of a rectangular plate 15 partially closes this opening, maintaining a passage 115 for the fluid communication between the upper compartment C'1 and the lower compartment C'2. This removable plate is supported by a so-called central vertical wall 122, passing through the axis A 'of the tank, and separating the lower compartment in two. Advantageously, the removable plate also bears on the main vertical walls 120. A transverse vertical wall 123 connects the two main vertical walls transversely at the level of the free zone, the central vertical wall extending from this vertical wall transverse to the side wall of the tank. This transverse wall is open at the bottom for the passage of effluents from the substrate to the free zone 108.

As before, the tank comprises hooks 103 for hooking a filter bag (not shown), and a lid 113 equipped with an intake duct 104, 2909371 12 and vents 118. A discharge pipe 106 equipped of an evacuation valve 161, sealingly passes through the side wall 112 of the tank, at the upper compartment 0'1, extends downwards along the side wall and passes through the wall of separation 114 to open in the free zone 108 of the lower compartment. A purge duct 162 opening at the bottom of the free zone is also provided to purge the vessel.

Although the invention has been described in connection with a particular embodiment, it is obvious that it is in no way limited thereto and that it comprises all the technical equivalents of the means described, as well as their combinations if those are within the scope of the invention.

Claims (10)

  1. Tank for the treatment of effluents, particularly fairing effluents, intended to be placed on the ground, characterized in that it comprises a separating wall (14, 114) delimiting inside the tank. an upper compartment (C1, C'1) and a lower compartment (C2, C'2), said compartments being in fluid communication with at least one passage (15, 115) of said partition wall, said upper compartment being equipped at least one filter bag (9), and said lower compartment being at least partially filled with a substrate (S), - intake means (4, 104) capable of delivering effluents to be treated in the part upper compartment of the upper compartment so that the effluents are discharged into the filter bag, and - evacuation means (6, 106) able to evacuate the effluent out of the tank by gravity, from the lower compartment after passing through the substrate.   2. Tank according to claim 1, characterized in that the evacuation means comprise at least one evacuation line (6, 106) equipped with a valve (61, 161), opening into said lower compartment (C2, C'2), said pipe being disposed above and opposite said passage (15, 115) of the partition wall (14, 114).   3. Tank according to claim 1 or 2, characterized in that said partition wall (114) is adapted to support the filter bag (9). 2909371 14   4. Tank according to claim 3, characterized in that the partition wall (114) is supported by at least two parallel vertical walls (120) which laterally delimit said lower compartment (0'2).   5. Tank according to one of claims 1 to 4, characterized in that said partition wall (114) is at least partially removable.   6. Tank according to one of claims 1 to 5, characterized in that it comprises a removable cover (13, 113).   7. Tank according to one of claims 1 to 6, characterized in that said intake means comprise at least one intake pipe (4, 104) 15 carried by said cover (13, 113).   8. Tank according to one of claims 1 to 7, characterized in that it comprises hooking means (3, 103) for hanging the filter bag (9) by its upper edge. 20   9. Tank according to one of claims 1 to 8, characterized in that it is equipped with a pump (5) connected to said inlet means (4, 104) for the transfer of effluent to be treated in the tank .   10. Processing tank according to one of claims 1 to 9, characterized in that the lower compartment (C2, C'2) is at least partially filled with a porous substrate based on zeolites.