WO2010081903A1 - Device for coating with a flocculating polymer material in the liquid state of ballast particles used for the treatment of water by ballasted flocculation, and corresponding facility - Google Patents

Device for coating with a flocculating polymer material in the liquid state of ballast particles used for the treatment of water by ballasted flocculation, and corresponding facility Download PDF

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Publication number
WO2010081903A1
WO2010081903A1 PCT/EP2010/050534 EP2010050534W WO2010081903A1 WO 2010081903 A1 WO2010081903 A1 WO 2010081903A1 EP 2010050534 W EP2010050534 W EP 2010050534W WO 2010081903 A1 WO2010081903 A1 WO 2010081903A1
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WO
WIPO (PCT)
Prior art keywords
polymer
grains
chamber
water
ballast
Prior art date
Application number
PCT/EP2010/050534
Other languages
French (fr)
Inventor
Zhou Genfeng
Wu QIN
Original Assignee
Otv Sa
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Otv Sa filed Critical Otv Sa
Publication of WO2010081903A1 publication Critical patent/WO2010081903A1/en

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Classifications

    • 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
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/5236—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents
    • C02F1/5245—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using inorganic agents using basic salts, e.g. of aluminium and iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
    • B01J2/006—Coating of the granules without description of the process or the device by which the granules are obtained
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2/00—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic
    • B01J2/02—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops
    • B01J2/04—Processes or devices for granulating materials, e.g. fertilisers in general; Rendering particulate materials free flowing in general, e.g. making them hydrophobic by dividing the liquid material into drops, e.g. by spraying, and solidifying the drops in a gaseous medium
    • 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
    • C02F1/52—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities
    • C02F1/54—Treatment of water, waste water, or sewage by flocculation or precipitation of suspended impurities using organic material
    • C02F1/56—Macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2305/00—Use of specific compounds during water treatment
    • C02F2305/12—Inert solids used as ballast for improving sedimentation

Definitions

  • the field of the invention is that of the treatment of water with a view to its purification or of its potabilization.
  • the invention relates to the treatment of water including in particular a solid-liquid separation by weighted flocculation and decantation.
  • This type of treatment generally includes a coagulation step.
  • Coagulation causes agglomeration of fine particles (colloidal) suspended in water. This is most often obtained by injecting into water a coagulating reagent which may for example be constituted by a trivalent metal salt.
  • the water thus coagulated then undergoes a flocculation step.
  • Flocculation causes the formation of flocs by agglomeration of the previously coagulated colloidal particles. This is most often obtained by injecting into the coagulated water a flocculating reagent usually consisting of an organic polymer.
  • the coagulated and then flocculated water undergoes a settling step in order to separate these flocs from the water.
  • Decantation is obtained by passing the water inside a decanter under which the sludge formed are extracted while the treated water is extracted overflow.
  • the treated water can then be conveyed to a filtration device placed downstream of the installation necessary for carrying out coagulation, flocculation and decantation in order to undergo a subsequent polishing treatment.
  • the so-called weighted flocculation technology has been developed.
  • Weighted flocculation consists in using a ballast or ballast generally consisting of a fine granular material of high density which is injected directly into the flocculation zone or upstream thereof.
  • ballast for reasons of availability and cost is the microsable. Other forms of ballast can also be implemented.
  • the ballast is in practice separated from the sludge extracted from the settling tank so as to be recycled at one or more points of the process.
  • ballast however, can not be recycled in its entirety, so that some of the ballast losses are observed by the treated water extracted over the decanter and by the sludge extracted in the underflow.
  • the sludge and the ballast extracted in the underflow are generally separated from each other for example by hydrocycloning.
  • the mixture of sludge and ballast extracted underneath the decanter is therefore conveyed inside a hydrocyclone from which is extracted a mixture sludge / ballast slightly loaded in overflow ballast, and a ballast / sludge mixture slightly loaded with sludge. underflow.
  • the sludge-rich mixture is in the majority of cases partly recycled in the process and partly directed to a sludge treatment zone.
  • the ballast-rich mixture is recycled in the process, either upstream of the flocculation zone or directly within it.
  • Such a weighted flocculation water treatment method is particularly advantageous in that it makes it possible to accelerate the speed of water treatment and consequently to reduce the size of the installations used for this purpose. It is all the more interesting when it plans moreover the implementation a sludge / ballast separation technique in that this leads to a significant reduction in ballast consumption and consequently the associated cost.
  • ballasted flocculation technique thus has a large number of advantages, as has just been explained.
  • the present invention however aims to further increase the performance.
  • the invention has the objective of providing, in at least one embodiment, such a technique which leads to improving the clarification of the water to be treated by the implementation of a treatment method including weighted flocculation. .
  • the invention aims, in at least one embodiment, to optimize maturation and flocculation in a weighted flocculation water treatment.
  • An objective of the invention is also, in at least one embodiment of the invention, to maximize the agglomeration of the colloidal particles around the ballast grains.
  • Another objective of the invention is to implement, in at least one embodiment of the invention, such a technique that makes it possible to limit the overdose of reagents injected into the water, and to increase the duration accordingly. filtration of a filtration device placed downstream of an installation necessary for the implementation of a weighted flocculation water treatment.
  • the invention also aims to provide, in at least one embodiment of the invention, such a technique that is simple to implement and is cheap while being reliable and efficient.
  • said device comprises a chamber, means for introducing said grains into said chamber, means for injecting said polymer in the liquid state into said chamber, means for contacting said grains and said polymer with said the liquid state, and means for discharging grains coated with said polymer at the periphery of said chamber.
  • the technique presented here is based on a completely novel approach to a ballast coating technique that, when implemented in a weighted flocculation water treatment process, can be used to increase the level of performance.
  • This technique involves contacting a flocculant polymer in the liquid state and ballast grains within an enclosure so as to produce ballast grains coated with flocculating polymer.
  • the coated grains thus formed are then discharged at the periphery of this enclosure, that is to say in a manner substantially comparable to that in which drops of water flow from the edges of an umbrella.
  • Coating the flocculant polymer ballast makes it possible to promote the agglomeration of the colloidal particles coagulated into flocs around the ballast grains.
  • coated grains are removed at the periphery of the chamber within which they are obtained leads to promote their distribution and dispersion inside the flocculation reactor. This also promotes the agglomeration of colloidal particles coagulated into flocs around the ballast grains.
  • the implementation of a coating technique according to the invention therefore makes it possible to optimize the maturation and to reduce the concentration of colloidal particles in the treated water.
  • the implementation of a coating technique according to the invention therefore makes it possible to increase the filtration time of the devices filtration plants placed downstream of the facilities necessary for the implementation of a weighted flocculation water treatment.
  • said introduction means comprise an opening intended to cooperate with the underflow of a hydrocyclone.
  • a coating device according to the invention can thus easily be secured to the opening of a hydrocyclone so as to allow the coating of the ballast grains that escape.
  • said injection means (17) comprise means for flowing said polymer at the inner periphery of said chamber (1 1), and means for projecting said grains onto said polymer (26).
  • Spraying ballast grains onto flocculant polymer in the liquid state effectively provides for coated ballast grains.
  • said projection means comprise a dispersing member of said grains towards said polymer or the inner periphery of said chamber, said dispersing member being placed opposite said introduction means.
  • a device comprises a substantially tubular element concentric with respect to said means for introducing said grains, said flow means being formed by a plurality of slots provided at the periphery of said tubular element.
  • This implementation makes it possible to simply and efficiently obtain a polymer film.
  • the inner surface of said tubular element is at least partly covered by a release material.
  • a release material makes it possible to facilitate the gravity unloading of the ballast grains coated outside the coating device according to the invention.
  • said release material is advantageously constituted by rubber.
  • a coating device advantageously comprises an enclosure forming a reserve of said polymer, said resist having an inlet cooperating with polymer supply means and an outlet cooperating with said injection means.
  • said enclosure preferably has at least one air inlet.
  • the invention also relates to a water treatment plant comprising a weighted flocculation tank, a decanter communicating with said flocculation tank, a hydrocyclone having a port and whose inlet is connected to the underflow of the settling tank.
  • such an installation comprises a coating device with a flocculant polymer material in the liquid state of ballast grains used for the treatment of water by weighted flocculation, said device comprising a chamber, means for introducing said grains into said chamber, means for injecting said polymer in the liquid state into said chamber, means for contacting said grains and said polymer in the liquid state, and means for discharging grains coated with said polymer at the periphery of said chamber, said introduction means comprising an opening intended to cooperate with said recess of said hydrocyclone, and said discharge means opening into said weighted flocculation tank.
  • An installation according to the invention advantageously comprises complementary injection means of said flocculant polymer material. It is thus possible to inject a portion of the flocculant polymer directly into the flocculation zone and a part in the form of a coating of the ballast grains.
  • said weighted flocculation tank and said settling tank are separated by a wall, said weighted flocculation tank and said settler communicating in the upper part and in the lower part of said wall, said complementary injection means comprise a perforated tube running along the lower part of said wall.
  • FIG. 1 is a longitudinal sectional view of a coating device according to the invention
  • Figure 2 is a perspective view of the coating device illustrated in Figure 1 which is secured to a hydrocyclone
  • FIG. 3 represents a diagram of a weighted flocculation water treatment installation which implements a coating device according to the invention
  • FIG. 4 represents a diagram of a variant of the installation illustrated in FIG.
  • Figures 5 and 6 are curves illustrating the filtration times of facilities placed downstream installation according to the invention identified during testing.
  • the general principle of the invention is based on the implementation of a technique for coating ballast grains with a flocculant polymer in a weighted flocculation water treatment process so as to increase its performance.
  • the coating of the ballast grains is obtained according to the invention by means of a coating device which comprises an enclosure inside which ballast grains and a polymer in the liquid state are brought into contact with each other. periphery from which coated ballast grains are discharged.
  • Such a coating device when implemented in a weighted flocculation water treatment method, leads in particular to: improving the maturation step during flocculation, and therefore reducing the colloidal particle concentration of the treated water collected at the outlet of a weighted flocculation plant; to increase the filtration time of the filtration devices placed downstream of the weighted flocculation plant.
  • FIG. 1 shows an embodiment of a coating device with ballast grain polymer used for the treatment of water by weighted flocculation.
  • such a coating device 10 comprises a chamber 11.
  • the contours of this chamber 11 are defined by a tubular element 12.
  • the tubular element 12 has a circular section. It can of course be provided in variants of this embodiment, the section of this tubular element 12 is different.
  • a lower portion of the tubular element 12 is covered by a release material 13.
  • this non-stick material will be made of rubber.
  • the upper part of the tubular element 11 has an opening 14 which defines means for introducing ballast grains inside the enclosure 11.
  • the opening 14 is arranged to cooperate with the container 15. a hydrocyclone 16.
  • the coating device according to the invention also comprises polymer injection means inside the chamber 1 1. These injection means here consist of a plurality of lights 17 which are arranged at the periphery of the upper end of the tubular element 12.
  • These lights 17 communicate with a reserve 18 of polymer. They advantageously have a diameter equal to 1/10 of the diameter of the tubular element 12 in which they are arranged
  • the contours of the polymer reserve 18 are defined by a second tubular element 19.
  • the lower end of this second tubular element 19 is closed by a bottom wall 20 while its upper end is closed by an upper wall 21.
  • the tubular element 19 as well as the upper and lower walls 20, 21 define a second enclosure 23.
  • the bottom wall 20 is traversed by the tubular element 12 which goes up inside the enclosure 23 so as to form the reserve 18.
  • the upper wall 21 is traversed by an opening 22 which allows the introduction of the underflow 15 of the hydrocyclone 16.
  • the second tubular element 19 is traversed in an upper part by air inlets 24 and has an inlet 25 in a lower portion of the supply 18 which cooperates with polymer supply means (not shown).
  • the coating device 10 also comprises means for projecting the ballast grains 28 onto the polymer 26 which flows on the inner wall of the tubular element 12.
  • These projection means comprise a dispersion member of the grains against the inner surface of the tubular element 12.
  • This dispersion member here takes the form of a cup 27 defining a cone placed at the outlet of the underflow 15 of the hydrocyclone 16.
  • the tip of this cup 27 extends in the extension of the axis A common to the underflow 15 and to the tubular element 12 while its lower end extends to near the inner wall of the tubular element 12.
  • a coating device according to the invention may be solidarisé directly to a hydrocyclone by the implementation of any suitable attachment means as it appears more clearly in Figure 2.
  • a coating device according to the invention is intended to be implemented within a weighted flocculation water treatment plant such as that illustrated in FIG.
  • An installation of this type comprises means of arrival of a previously coagulated water which here take the form of a pipe 30.
  • This pipe 30 opens into a maturation tank 31.
  • the coagulated water is brought into contact with: a flocculant polymer which is injected into this tank by the implementation of complementary injection means comprising an injector 35; with new ballast grains by the implementation of injection means
  • the installation also comprises a hydrocyclone 16 whose underflow is connected to the inlet of a coating device 10 according to the invention so as to allow the injection of ballast grains coated with flocculant polymer in the tank maturation 31.
  • the maturation tank 31 is separated from a decanter 32 by means of a wall 40. It communicates in the upper part of this wall 40 with the decanter 32 so that the coagulated and flocculated water passes therethrough so as to separate the phase liquid from the solid phase by settling the ballasted flocs.
  • the overflow 34 of the clarifier 32 allows the evacuation of a treated water while the underflow of the decanter 32 allows the evacuation of a mixture of ballast and sludge resulting from the treatment of water by weighted flocculation.
  • the treated water is discharged towards a polishing zone which comprises a filtration device 38.
  • the sludge is conveyed via a pipe 33 connected to the trencher of the decanter 32 at the inlet of the hydrocyclone 16.
  • the implementation of the hydrocyclone 16 separates the sludge from the ballast: a mixture of sludge /
  • the lightly loaded ballast ballast discharged in overflow is partly directed to a sludge treatment zone by means of a pipe 36 and partly recycled to the maturation tank 31 or upstream thereof by means of a pipe 37 ; a ballast / sludge mixture slightly loaded with sludge discharged underflow is directed towards the inlet of the coating device according to the invention 10.
  • the complementary polymer injection means flocculent have a shape other than that of the injector 35.
  • the maturation tank 31 and the decanter 32 communicate in the upper part and in the lower part of the wall 40, a space 41 being formed between the lower part of this wall 40 and the bottom of the maturation tank 31.
  • the complementary injection means comprise a perforated tube 42 which extends along the space 41 and which is housed in the decanter 32.
  • the perforations passing through this tube 42 advantageously have a diameter equal to 1/10 of the diameter of the tube 42.
  • the curing tank 31 is replaced by a tank for contacting the water with the flocculating polymer and with the ballast, which is followed by a flocculation tank .
  • the contacting tank and the flocculation tank are separated by a wall similar to the wall 40, a space being provided between the bottom of the maturation and flocculation tanks and the lower part of the wall 40.
  • the additional injection means of polymer may take the form of a perforated tube similar to the tube 42 which will be placed opposite the space formed in the lower part of the wall.
  • the flocculation tank houses an agitator surrounded by a tubular element forming a flow guide. The perforated tube 42 will then be placed near the stirrer.
  • a flocculant polymer in the liquid state is injected inside the reserve 18 by the implementation of feed means connected to the inlet 25 of the reserve 18.
  • the polymer in the liquid state consists of a stock solution containing from 1 to 3 g of polymer per liter.
  • This mother solution is itself diluted by a dilution factor between 1 and 10 (ie one liter of stock solution is diluted in 1 to 10 liters of water).
  • the dilution of the polymer facilitates its distribution within the installation and increases the performance of the system. This makes it possible to limit the dosage of the polymer.
  • the reduction of the polymer dosage makes it possible: to limit the polymer consumption and thus to reduce the operating costs of a treatment plant; to limit the amount of residual polymer present in the treated water at the outlet of the installation, which limits its impact on the treatments placed downstream of the installation. In particular, if it is planned to implement a further filtration treatment downstream of the installation, the membranes used for this purpose will be less prone to clogging and their filtration time will be increased.
  • ballast grains 28 from the underflow flow over the dispersing member 27 so that they are projected onto the polymer 26 as shown by the arrows P.
  • ballast grains projected on the polymer are covered with polymer and flow by gravity while moving along the inner surface covered with rubber 13.
  • the flow by gravity is favored by the air inlets 24 formed in the part upper part of the second tubular element 19.
  • the coated ballast grains 29 flow outside the coating device by the periphery of the tubular element 12 in a manner equivalent to the flow of drops of water from the edges of an umbrella, which facilitates their dispersion inside the maturation tank 31.
  • the polymer used will preferably be of type: strongly charged anionic in the case of treatment of highly mineralized water; anionic charge lower in the case of the treatment of a water loaded with MES and whose alkalinity is greater than 5 ° French noted TAC; - Cationic or anionic with very little charge in the case of the treatment of a soft or very fresh water loaded with colloids.
  • a first series of tests consisted in measuring the filtration time of filters placed downstream of a weighted flocculation water treatment plant in which the flocculant polymer was injected directly into the maturation tank without the use of a coating device according to the invention.
  • a second series of tests consisted in measuring the filtration time of filters placed downstream of a weighted flocculation water treatment plant implementing a coating device according to the invention and in which the flocculating polymer (in this case AN905: anionic acrylamide polymer marketed by the company Floerger) was injected at two points: - 50% of the polymer was injected in a conventional manner directly into the maturation tank or into the decanter by the implementation of complementary injection means;
  • Figures 5 and 6 are curves that illustrate the results of other tests.
  • FIG. 5 illustrates the filtration time of a filtration device placed downstream of an installation according to the invention respectively with a one-point injection of polymers AN 923 and WT 652 in a conventional manner.
  • FIG. 6 illustrates the filtration time of a filtration device placed downstream from an installation according to the invention respectively with an injection injected into two polymer polymer points AN 923 and WT 652: 50% of the polymer was injected in a conventional manner directly into the maturation tank or into the decanter by the implementation of the complementary injection means;
  • 50% of the polymer was injected in the form of ballast grains coated by means of a device according to the invention.
  • the average filtration time of a downstream filtration device is about 17.5 hours when all of the AN 923 polymer is conventionally injected into the curing pan.
  • the average filtration time of a downstream filtration device becomes about 29 hours.
  • the average filtration time of a downstream filtration device is about 15 hours when all of the WT 652 polymer is conventionally injected into the curing pan.
  • the average filtration time of a downstream filtration device becomes approximately 23 hours.
  • the implementation of the invention therefore makes it possible to increase from 50 to more than 60% the filtration time of a filtration device placed downstream of a weighted flocculation water treatment installation.
  • part of the flocculant polymer is in the form of a coating of the ballast grains, favoring the agglomeration of the colloidal particles directly around the grains. of ballast and consequently reducing the particle concentration of the treated water by weighted flocculation.
  • the flocculating polymer makes it possible, by virtue of the best use of the flocculating polymer that it allows, to reduce the amount of polymer necessary for the treatment. It also makes it possible to increase the filtration time of the filtration devices placed downstream of the water treatment plants by weighted flocculation, which leads to a reduction in the cost of water treatment. Indeed, the implementation of the technique according to the invention makes it possible to reduce the quantity of flocculant polymer injected into the water and thus to limit the polymer overdoses, which have the consequence of increasing the clogging of the membranes placed downstream. .
  • the implementation of the technique according to the invention thus makes it possible to obtain a clarified water of equivalent quality to that of a water treated by flotation or without the addition of a polymer and whose clogging power is lower than that of a conventionally treated water with flocculant polymer injection.
  • the implementation of the technique according to the invention makes it possible to benefit from the advantages associated with the use of flocculating polymer (speed of treatment, ease of implementation, etc.) without suffering the disadvantages thereof ( clogging downstream membranes).

Abstract

The invention relates to a device for coating with a flocculating polymer material in the liquid state of ballast particles used for the treatment of water by ballasted flocculation, said device comprising: a chamber; means for introducing said particles into said chamber; means for injecting said polymer in the liquid state into said chamber; means for bringing said particles into contact with said polymer in the liquid state; and means for discharging particles coated with said polymer, these being located on the periphery of said chamber.

Description

Dispositif d'enrobage avec un matériau polymère floculant à l'état liquide de grains de ballast utilisés pour le traitement de l'eau par floculation lestée, et installation correspondante Coating device with a flocculant polymer material in the liquid state of ballast grains used for the treatment of water by weighted flocculation, and corresponding installation
1. Domaine de l'invention Le domaine de l'invention est celui du traitement de l'eau en vue de son épuration ou de sa potabilisation.FIELD OF THE INVENTION The field of the invention is that of the treatment of water with a view to its purification or of its potabilization.
Plus précisément, l'invention concerne le traitement de l'eau incluant notamment une séparation solide-liquide par floculation lestée et une décantation.More specifically, the invention relates to the treatment of water including in particular a solid-liquid separation by weighted flocculation and decantation.
2. Art antérieur Le traitement des eaux, qu'il soit mis en œuvre dans le but de potabiliser des eaux de surface, des eaux karstiques..., ou d'épurer des eaux usées urbaines ou industrielles, est obtenu par la mise en œuvre de procédés qui incluent une succession d'étapes.2. PRIOR ART The treatment of water, whether it is used for the purpose of potabilizing surface water, karstic water ..., or of purifying urban or industrial wastewater, is obtained by the implementation of processes that include a succession of steps.
Ce type de traitement inclut en général une étape de coagulation. La coagulation engendre une agglomération des particules fines (colloïdales) en suspension dans l'eau. Ceci est le plus souvent obtenu en injectant dans l'eau un réactif coagulant pouvant par exemple être constitué par un sel de métal trivalent.This type of treatment generally includes a coagulation step. Coagulation causes agglomeration of fine particles (colloidal) suspended in water. This is most often obtained by injecting into water a coagulating reagent which may for example be constituted by a trivalent metal salt.
L'eau ainsi coagulée subit ensuite une étape de floculation. La floculation engendre la formation de flocs par agglomération des particules colloïdales préalablement coagulées. Ceci est le plus souvent obtenu en injectant dans l'eau coagulée un réactif floculant constitué usuellement d'un polymère organique.The water thus coagulated then undergoes a flocculation step. Flocculation causes the formation of flocs by agglomeration of the previously coagulated colloidal particles. This is most often obtained by injecting into the coagulated water a flocculating reagent usually consisting of an organic polymer.
Finalement, l'eau coagulée puis floculée subit une étape de décantation afin de séparer ces flocs de l'eau. La décantation est obtenue en faisant transiter l'eau à l'intérieur d'un décanteur en sousverse duquel les boues formées sont extraites alors que l'eau traitée est extraite en surverse. L'eau traitée peut ensuite être acheminée vers un dispositif de filtration placé en aval de l'installation nécessaire à la mise en œuvre de la coagulation, de la floculation et de la décantation afin de subir un traitement ultérieur de polissage. Afin d'améliorer la vitesse de formation des flocs et leur vitesse de décantation, la technologie dite de floculation lestée a été développée.Finally, the coagulated and then flocculated water undergoes a settling step in order to separate these flocs from the water. Decantation is obtained by passing the water inside a decanter under which the sludge formed are extracted while the treated water is extracted overflow. The treated water can then be conveyed to a filtration device placed downstream of the installation necessary for carrying out coagulation, flocculation and decantation in order to undergo a subsequent polishing treatment. In order to improve the formation speed of the flocs and their settling speed, the so-called weighted flocculation technology has been developed.
La floculation lestée consiste à mettre en œuvre un lest ou ballast généralement constitué d'un matériau granulaire fin de forte densité qui est injecté directement dans la zone de floculation ou en amont de celle-ci.Weighted flocculation consists in using a ballast or ballast generally consisting of a fine granular material of high density which is injected directly into the flocculation zone or upstream thereof.
Le ballast le plus utilisé pour des raisons de disponibilité et de coût est le microsable. D'autres formes de ballast peuvent également être mises en œuvre.The most used ballast for reasons of availability and cost is the microsable. Other forms of ballast can also be implemented.
Pour des raisons économiques, le ballast est dans la pratique séparé des boues extraites en souverse du décanteur de manière à être recyclé en un ou plusieurs points du procédé.For economic reasons, the ballast is in practice separated from the sludge extracted from the settling tank so as to be recycled at one or more points of the process.
Le ballast ne peut toutefois pas être recyclé en totalité en sorte que l'on observe quelques des pertes en ballast, par l'eau traitée extraite en surverse du décanteur, et par les boues extraites en sousverse.The ballast, however, can not be recycled in its entirety, so that some of the ballast losses are observed by the treated water extracted over the decanter and by the sludge extracted in the underflow.
Pour compenser ces pertes, on procède le plus souvent de façon régulière, à des injections de ballast frais dans le procédé.To compensate for these losses, it is most often done on a regular basis, injections of fresh ballast in the process.
Dans le but de s'efforcer de maîtriser au mieux les pertes en ballast par les boues extraites, les boues et le ballast extraits en sousverse sont en général séparés les uns des autres par exemple par hydrocyclonage. Le mélange de boues et de ballast extrait en sousverse du décanteur est pour cela acheminé à l'intérieur d'un hydrocyclone dont est extrait un mélange boues/ballast faiblement chargé en ballast en surverse, et un mélange ballast/boue faiblement chargé en boue en sousverse.In order to try to control the ballast losses as much as possible by the extracted sludge, the sludge and the ballast extracted in the underflow are generally separated from each other for example by hydrocycloning. The mixture of sludge and ballast extracted underneath the decanter is therefore conveyed inside a hydrocyclone from which is extracted a mixture sludge / ballast slightly loaded in overflow ballast, and a ballast / sludge mixture slightly loaded with sludge. underflow.
Le mélange riche en boues est dans la majorité des cas en partie recyclé dans le procédé et en partie dirigé vers une zone de traitement des boues. Le mélange riche en ballast est quant à lui recyclé dans le procédé, soit en amont de la zone de floculation soit directement au sein de celle-ci.The sludge-rich mixture is in the majority of cases partly recycled in the process and partly directed to a sludge treatment zone. The ballast-rich mixture is recycled in the process, either upstream of the flocculation zone or directly within it.
Un tel procédé de traitement d' eau par floculation lestée est particulièrement intéressant en ce qu'il permet d'accélérer la vitesse de traitement de l'eau et de réduire en conséquence la taille des installations mises en œuvre à cet effet. Il est d'autant plus intéressant lorsqu'il prévoit de plus la mise en œuvre d'une technique de séparation boues/ballast en ce que cela conduit à réduire de façon significative la consommation en ballast et par conséquent le coût qui y est associé.Such a weighted flocculation water treatment method is particularly advantageous in that it makes it possible to accelerate the speed of water treatment and consequently to reduce the size of the installations used for this purpose. It is all the more interesting when it plans moreover the implementation a sludge / ballast separation technique in that this leads to a significant reduction in ballast consumption and consequently the associated cost.
La technique dite de floculation lestée présente donc un grand nombre d'avantages, tel que cela vient d'être expliqué. La présente invention vise toutefois à en accroître encore davantage les performances.The so-called ballasted flocculation technique thus has a large number of advantages, as has just been explained. The present invention however aims to further increase the performance.
3. Objectifs de l'invention3. Objectives of the invention
Plus précisément, un objectif de l'invention est de fournir une technique qui permette d'améliorer le traitement de l'eau par floculation lestée. Notamment, l'invention poursuit l'objectif de fournir, dans au moins un mode de réalisation, une telle technique qui conduise à améliorer la clarification de l'eau à traiter par la mise en œuvre d'un procédé de traitement incluant une floculation lestée.More precisely, it is an object of the invention to provide a technique which makes it possible to improve the treatment of water by weighted flocculation. In particular, the invention has the objective of providing, in at least one embodiment, such a technique which leads to improving the clarification of the water to be treated by the implementation of a treatment method including weighted flocculation. .
En particulier, l'invention vise, dans au moins un mode de réalisation, à optimiser la maturation et la floculation dans un traitement d'eau par floculation lestée.In particular, the invention aims, in at least one embodiment, to optimize maturation and flocculation in a weighted flocculation water treatment.
Un objectif de l'invention est également, dans au moins un mode de réalisation de l'invention, de maximiser l'agglomération des particules colloïdales autour des grains de ballast. Un autre objectif de l'invention est de mettre en œuvre, dans au moins un mode de réalisation de l'invention, une telle technique qui permette de limiter le surdosage de réactifs injectés dans l'eau, et d'accroître en conséquence la durée de fîltration d'un dispositif de fîltration placé en aval d'une installation nécessaire à la mise en œuvre d'un traitement d'eau par floculation lestée. L'invention a encore pour objectif de fournir, dans au moins un mode de réalisation de l'invention, une telle technique qui soit simple à mettre en œuvre et qui soit bon marché tout en étant fiable et performante.An objective of the invention is also, in at least one embodiment of the invention, to maximize the agglomeration of the colloidal particles around the ballast grains. Another objective of the invention is to implement, in at least one embodiment of the invention, such a technique that makes it possible to limit the overdose of reagents injected into the water, and to increase the duration accordingly. filtration of a filtration device placed downstream of an installation necessary for the implementation of a weighted flocculation water treatment. The invention also aims to provide, in at least one embodiment of the invention, such a technique that is simple to implement and is cheap while being reliable and efficient.
4. Exposé de l'invention4. Presentation of the invention
Ces objectifs, ainsi que d'autres qui apparaîtront par la suite, sont atteints à l'aide d'un dispositif d'enrobage avec un matériau polymère floculant à l'état liquide de grains de ballast utilisés pour le traitement de l'eau par floculation lestée.These objectives, as well as others that will appear later, are achieved by means of a coating device with a flocculant polymer material in the state liquid of ballast grains used for the treatment of water by weighted flocculation.
Selon l'invention, ledit dispositif comprend une chambre, des moyens d'introduction desdits grains dans ladite chambre, des moyens d'injection dudit polymère à l'état liquide dans ladite chambre, des moyens de mise en contact desdits grains et dudit polymère à l'état liquide, et des moyens de décharge de grains enrobés dudit polymère en périphérie de ladite chambre.According to the invention, said device comprises a chamber, means for introducing said grains into said chamber, means for injecting said polymer in the liquid state into said chamber, means for contacting said grains and said polymer with said the liquid state, and means for discharging grains coated with said polymer at the periphery of said chamber.
Ainsi, la technique présentée ici repose sur une approche tout à fait originale concernant une technique d'enrobage des grains de ballast qui, lorsqu'elle est mise en œuvre dans un procédé de traitement d'eau par floculation lestée, permet d'en accroître le niveau de performance.Thus, the technique presented here is based on a completely novel approach to a ballast coating technique that, when implemented in a weighted flocculation water treatment process, can be used to increase the level of performance.
Cette technique consiste à mettre en contact un polymère floculant à l'état liquide et des grains de ballast au sein d'une enceinte de manière à produire des grains de ballast enrobés de polymère floculant. Les grains enrobés ainsi formés sont ensuite évacués en périphérie de cette enceinte, c'est-à-dire d'une manière sensiblement comparable à celle selon laquelle des gouttes d'eau s'écoulent depuis les rebords d'un parapluie.This technique involves contacting a flocculant polymer in the liquid state and ballast grains within an enclosure so as to produce ballast grains coated with flocculating polymer. The coated grains thus formed are then discharged at the periphery of this enclosure, that is to say in a manner substantially comparable to that in which drops of water flow from the edges of an umbrella.
Le fait d'enrober le ballast de polymère floculant, telle que le permet la présente invention, permet de favoriser l'agglomération des particules colloïdales coagulées en flocs autour des grains de ballast.Coating the flocculant polymer ballast, as permitted by the present invention, makes it possible to promote the agglomeration of the colloidal particles coagulated into flocs around the ballast grains.
En outre, le fait de prévoir que les grains enrobés sont évacués en périphérie de l'enceinte au sein de laquelle ils sont obtenus conduit à favoriser leur distribution et leur dispersion à l'intérieur du réacteur de floculation. Ceci favorise également l'agglomération des particules colloïdales coagulées en flocs autour des grains de ballast.In addition, providing that the coated grains are removed at the periphery of the chamber within which they are obtained leads to promote their distribution and dispersion inside the flocculation reactor. This also promotes the agglomeration of colloidal particles coagulated into flocs around the ballast grains.
La mise en œuvre d'une technique d'enrobage selon l'invention permet donc d'optimiser la maturation et de réduire la concentration en particules colloïdales de l'eau traitée. La mise en œuvre d'une technique d'enrobage selon l'invention permet par conséquent d'accroître la durée de fïltration des dispositifs de fïltration placés en aval des installations nécessaires à la mise en œuvre d'un traitement d'eau par floculation lestée.The implementation of a coating technique according to the invention therefore makes it possible to optimize the maturation and to reduce the concentration of colloidal particles in the treated water. The implementation of a coating technique according to the invention therefore makes it possible to increase the filtration time of the devices filtration plants placed downstream of the facilities necessary for the implementation of a weighted flocculation water treatment.
Préférentiellement, lesdits moyens d'introduction comprennent une ouverture destinée à coopérer avec la sousverse d'un hydrocyclone. Un dispositif d'enrobage selon l'invention peut ainsi être facilement solidarisé à la souverse d'un hydrocyclone de manière à permettre l'enrobage des grains de ballast qui s'en échappent.Preferably, said introduction means comprise an opening intended to cooperate with the underflow of a hydrocyclone. A coating device according to the invention can thus easily be secured to the opening of a hydrocyclone so as to allow the coating of the ballast grains that escape.
Selon une caractéristique avantageuse, lesdits des moyens d'injection (17) comprennent des moyens d'écoulement dudit polymère à la périphérie intérieure de ladite chambre (1 1), et des moyens de projection desdits grains sur ledit polymère (26).According to an advantageous characteristic, said injection means (17) comprise means for flowing said polymer at the inner periphery of said chamber (1 1), and means for projecting said grains onto said polymer (26).
La projection de grains de ballast sur du polymère floculant à l'état liquide permet d'obtenir de manière efficace des grains de ballast enrobés.Spraying ballast grains onto flocculant polymer in the liquid state effectively provides for coated ballast grains.
Préférentiellement, lesdits moyens de projection comprennent un organe de dispersion desdits grains en direction dudit polymère ou de la périphérie intérieure de ladite chambre, ledit organe de dispersion étant placé en regard desdits moyens d'introduction.Preferably, said projection means comprise a dispersing member of said grains towards said polymer or the inner periphery of said chamber, said dispersing member being placed opposite said introduction means.
La mise en œuvre de tels moyens de dispersion permet d'améliorer l'uniformité de la projection des grains de ballast sur le polymère. Avantageusement, un dispositif selon l'invention comprend un élément essentiellement tubulaire concentrique par rapport auxdits moyens d'introduction desdits grains, lesdits moyens d'écoulement étant formés par une pluralité de lumières ménagées à la périphérie dudit élément tubulaire.The implementation of such dispersing means makes it possible to improve the uniformity of the projection of the ballast grains on the polymer. Advantageously, a device according to the invention comprises a substantially tubular element concentric with respect to said means for introducing said grains, said flow means being formed by a plurality of slots provided at the periphery of said tubular element.
Cette mise en œuvre permet d'obtenir simplement et efficacement un film de polymère.This implementation makes it possible to simply and efficiently obtain a polymer film.
Selon un autre aspect préféré de l'invention, la surface intérieure dudit élément tubulaire est au moins en partie recouverte par un matériau anti-adhérant. La mise en œuvre d'un tel matériau anti-adhérent permet de faciliter le déchargement par gravité des grains de ballast enrobés en dehors du dispositif d'enrobage selon l'invention. Dans ce cas, ledit matériau anti-adhérant est avantageusement constitué par du caoutchouc.According to another preferred aspect of the invention, the inner surface of said tubular element is at least partly covered by a release material. The implementation of such a release material makes it possible to facilitate the gravity unloading of the ballast grains coated outside the coating device according to the invention. In this case, said release material is advantageously constituted by rubber.
Un dispositif d'enrobage selon l'invention comprend avantageusement une enceinte formant une réserve dudit polymère, ladite réserve présentant une entrée coopérant avec des moyens d'alimentation en polymère et une sortie coopérant avec lesdits moyens d'injection.A coating device according to the invention advantageously comprises an enclosure forming a reserve of said polymer, said resist having an inlet cooperating with polymer supply means and an outlet cooperating with said injection means.
Dans ce cas, ladite enceinte présente de manière préférentielle au moins une entrée d'air.In this case, said enclosure preferably has at least one air inlet.
Ceci permet également de facilité le déchargement par gravité des grains de ballast enrobés en dehors du dispositif d'enrobage selon l'invention.This also makes it easier to unload by gravity the ballast grains coated outside the coating device according to the invention.
L'invention concerne également une installation de traitement d'eau comprenant une cuve de floculation lestée, un décanteur communiquant avec ladite cuve de floculation, un hydrocyclone présentant une souverse et dont l'entrée est reliée à la sousverse du décanteur. Selon l'invention, une telle installation comprend un dispositif d'enrobage avec un matériau polymère floculant à l'état liquide de grains de ballast utilisés pour le traitement de l'eau par floculation lestée, ledit dispositif comprenant une chambre, des moyens d'introduction desdits grains dans ladite chambre, des moyens d'injection dudit polymère à l'état liquide dans ladite chambre, des moyens de mise en contact desdits grains et dudit polymère à l'état liquide, et des moyens de décharge de grains enrobés dudit polymère en périphérie de ladite chambre, lesdits moyens d'introduction comprenant une ouverture destinée à coopérer avec ladite souverse dudit hydrocyclone, et lesdits moyens de décharge débouchant dans ladite cuve de floculation lestée. La mise en œuvre d'une telle installation permet d'accroître les capacités de traitement d'un procédé de traitement d'eau par floculation lestée. Elle conduit en effet à : améliorer l'étape de maturation au cours de la floculation, et donc de réduire la concentration en particules colloïdales de l'eau traitée recueillie à la sortie d'une installation de floculation lestée ; accroître la durée de fïltration des dispositifs de fïltration placés en aval de l'installation de floculation lestée.The invention also relates to a water treatment plant comprising a weighted flocculation tank, a decanter communicating with said flocculation tank, a hydrocyclone having a port and whose inlet is connected to the underflow of the settling tank. According to the invention, such an installation comprises a coating device with a flocculant polymer material in the liquid state of ballast grains used for the treatment of water by weighted flocculation, said device comprising a chamber, means for introducing said grains into said chamber, means for injecting said polymer in the liquid state into said chamber, means for contacting said grains and said polymer in the liquid state, and means for discharging grains coated with said polymer at the periphery of said chamber, said introduction means comprising an opening intended to cooperate with said recess of said hydrocyclone, and said discharge means opening into said weighted flocculation tank. The implementation of such an installation makes it possible to increase the processing capacities of a water treatment method by weighted flocculation. It indeed leads to: improving the ripening step during flocculation, and thus reducing the colloidal particle concentration of the treated water collected at the outlet of a weighted flocculation plant; to increase the filtration time of the filtration devices placed downstream of the ballasted flocculation plant.
Une installation selon l'invention comprend avantageusement des moyens d'injection complémentaire dudit matériau polymère floculant. II est ainsi possible d'injecter une partie du polymère floculant directement dans la zone de floculation et une partie sous la forme d'un enrobage des grains de ballast.An installation according to the invention advantageously comprises complementary injection means of said flocculant polymer material. It is thus possible to inject a portion of the flocculant polymer directly into the flocculation zone and a part in the form of a coating of the ballast grains.
Selon une caractéristique préférentielle, ladite cuve de floculation lestée et ledit décanteur sont séparés par une paroi, ladite cuve de floculation lestée et ledit décanteur communiquant en partie supérieure et en partie inférieure de ladite paroi, lesdits moyens d'injection complémentaire comprennent un tube perforé longeant la partie inférieure de ladite paroi.According to a preferred feature, said weighted flocculation tank and said settling tank are separated by a wall, said weighted flocculation tank and said settler communicating in the upper part and in the lower part of said wall, said complementary injection means comprise a perforated tube running along the lower part of said wall.
Ces moyens d'injection complémentaires permettent l'injection d'une certaine proportion du polymère floculant injecté en au moins un deuxième point du procédé. Ceci permet d'accroître encore davantage les capacité de traitement d'un procédé consistant en la mise en œuvre d'une installation selon l'invention.These complementary injection means allow the injection of a certain proportion of the injected flocculant polymer into at least a second point of the process. This makes it possible to further increase the processing capacity of a method consisting of the implementation of an installation according to the invention.
6. Liste des figures6. List of figures
D'autres caractéristiques et avantages de l'invention apparaîtront plus clairement à la lecture de la description suivante d'un mode de réalisation préférentiel, donné à titre de simple exemple illustratif et non limitatif, et des dessins annexés, parmi lesquels : la figure 1 est une vue en coupe longitudinale d'un dispositif d'enrobage selon l'invention ; la figure 2 est une vue en perspective du dispositif d'enrobage illustré à la figure 1 qui est solidarisé à un hydrocyclone ; la figure 3 représente un schéma d'une installation de traitement d'eau par floculation lestée qui met en œuvre un dispositif d'enrobage selon l'invention la figure 4 représente un schéma d'une variante de l'installation illustrée à la figure 3 ; les figures 5 et 6 sont des courbes illustrant les durées de fîltration d'installations placées en aval d'installation selon l'invention relevées au cours d'essais.Other features and advantages of the invention will emerge more clearly on reading the following description of a preferred embodiment, given as a simple illustrative and nonlimiting example, and the appended drawings, among which: FIG. 1 is a longitudinal sectional view of a coating device according to the invention; Figure 2 is a perspective view of the coating device illustrated in Figure 1 which is secured to a hydrocyclone; FIG. 3 represents a diagram of a weighted flocculation water treatment installation which implements a coating device according to the invention; FIG. 4 represents a diagram of a variant of the installation illustrated in FIG. ; Figures 5 and 6 are curves illustrating the filtration times of facilities placed downstream installation according to the invention identified during testing.
7. Description d'un mode de réalisation de l'invention 7.1. Rappel du principe général de l'invention7. Description of an embodiment of the invention 7.1. Reminder of the general principle of invention
Le principe général de l'invention repose sur la mise en œuvre d'une technique d'enrobage de grains de ballast avec un polymère floculant dans un procédé de traitement d'eau par floculation lestée de manière à en accroître les performances. L'enrobage des grains de ballast est obtenu selon l'invention au moyen d'un dispositif d'enrobage qui comprend une enceinte à l'intérieur de laquelle sont mis en contact des grains de ballast et un polymère à l'état liquide et en périphérie de laquelle des grains de ballast enrobés sont évacués.The general principle of the invention is based on the implementation of a technique for coating ballast grains with a flocculant polymer in a weighted flocculation water treatment process so as to increase its performance. The coating of the ballast grains is obtained according to the invention by means of a coating device which comprises an enclosure inside which ballast grains and a polymer in the liquid state are brought into contact with each other. periphery from which coated ballast grains are discharged.
Un tel dispositif d'enrobage, lorsqu'il est mis en œuvre au sein d'un procédé de traitement d'eau par floculation lestée, conduit notamment à : améliorer l'étape de maturation au cours de la floculation, et donc de réduire la concentration en particules colloïdales de l'eau traitée recueillie à la sortie d'une installation de floculation lestée ; accroître la durée de fîltration des dispositifs de fîltration placés en aval de l'installation de floculation lestée.Such a coating device, when implemented in a weighted flocculation water treatment method, leads in particular to: improving the maturation step during flocculation, and therefore reducing the colloidal particle concentration of the treated water collected at the outlet of a weighted flocculation plant; to increase the filtration time of the filtration devices placed downstream of the weighted flocculation plant.
7.2. Exemple d'un mode de réalisation d'un dispositif d'enrobage selon l'invention7.2. Example of an embodiment of a coating device according to the invention
On présente, en relation avec la figure 1, un mode de réalisation d'un dispositif d'enrobage avec du polymère de grains de ballast utilisés pour le traitement de l'eau par floculation lestée.FIG. 1 shows an embodiment of a coating device with ballast grain polymer used for the treatment of water by weighted flocculation.
Ainsi que cela est représenté sur cette figure 1, qui illustre une vue en coupe longitudinale d'un dispositif d'enrobage selon l'invention, un tel dispositif d'enrobage 10 comprend une enceinte 11. Les contours de cette enceinte 11 sont définis par un élément de forme tubulaire 12. Dans ce mode de réalisation, l'élément tubulaire 12 présente une section circulaire. Il pourra bien sûr être prévu, dans des variantes de ce mode de réalisation, que la section de cet élément tubulaire 12 soit différente.As shown in this figure 1, which illustrates a longitudinal sectional view of a coating device according to the invention, such a coating device 10 comprises a chamber 11. The contours of this chamber 11 are defined by a tubular element 12. In this embodiment, the tubular element 12 has a circular section. It can of course be provided in variants of this embodiment, the section of this tubular element 12 is different.
Une portion inférieure de l'élément tubulaire 12 est recouverte par un matériau anti-adhérent 13. De façon préférentielle, ce matériau anti-adhérent sera constitué par du caoutchouc.A lower portion of the tubular element 12 is covered by a release material 13. Preferably, this non-stick material will be made of rubber.
La partie supérieure de l'élément tubulaire 11 présente une ouverture 14 laquelle définit des moyens d'introduction de grains de ballast à l'intérieur de l'enceinte 11. L'ouverture 14 est agencée de manière à coopérer avec la souverse 15 d'un hydrocyclone 16. Le dispositif d'enrobage selon l'invention comprend également des moyens d'injection de polymère à l'intérieur de l'enceinte 1 1. Ces moyens d'injection sont ici constitués par une pluralité de lumières 17 qui sont ménagées à la périphérie de l'extrémité supérieure de l'élément tubulaire 12.The upper part of the tubular element 11 has an opening 14 which defines means for introducing ballast grains inside the enclosure 11. The opening 14 is arranged to cooperate with the container 15. a hydrocyclone 16. The coating device according to the invention also comprises polymer injection means inside the chamber 1 1. These injection means here consist of a plurality of lights 17 which are arranged at the periphery of the upper end of the tubular element 12.
Ces lumières 17 communiquent avec une réserve 18 de polymère. Elles présentent avantageusement un diamètre égal à 1/10 du diamètre de l'élément tubulaire 12 dans lequel elles sont ménagéesThese lights 17 communicate with a reserve 18 of polymer. They advantageously have a diameter equal to 1/10 of the diameter of the tubular element 12 in which they are arranged
Les contours de la réserve 18 de polymère sont définis par un deuxième élément tubulaire 19. L'extrémité inférieure de ce deuxième élément tubulaire 19 est fermée par une paroi inférieure 20 alors que son extrémité supérieure est fermée par une paroi supérieure 21.The contours of the polymer reserve 18 are defined by a second tubular element 19. The lower end of this second tubular element 19 is closed by a bottom wall 20 while its upper end is closed by an upper wall 21.
L'élément tubulaire 19 ainsi que les parois supérieure et inférieure 20, 21 définissent une deuxième enceinte 23.The tubular element 19 as well as the upper and lower walls 20, 21 define a second enclosure 23.
La paroi inférieure 20 est traversée par l'élément tubulaire 12 qui remonte à l'intérieur de l'enceinte 23 de manière à former la réserve 18. La paroi supérieure 21 est traversée par une ouverture 22 qui permet l'introduction de la sousverse 15 de l' hydrocyclone 16.The bottom wall 20 is traversed by the tubular element 12 which goes up inside the enclosure 23 so as to form the reserve 18. The upper wall 21 is traversed by an opening 22 which allows the introduction of the underflow 15 of the hydrocyclone 16.
Le deuxième élément tubulaire 19 est traversé dans une partie supérieure par des entrées d'air 24 et présente dans une partie inférieure de la réserve 18 une entrée 25 qui coopère avec des moyens d'alimentation en polymère (non représentés). Le dispositif d'enrobage 10 selon l'invention comprend également des moyens de projection des grains de ballast 28 sur le polymère 26 qui s'écoule sur la paroi intérieure de l'élément tubulaire 12. Ces moyens de projection comprennent un organe de dispersion des grains contre la surface intérieure de l'élément tubulaire 12. Cet organe de dispersion prend ici la forme d'une coupelle 27 définissant un cône placé en sortie de la sousverse 15 de l' hydrocyclone 16. La pointe de cette coupelle 27 s'étend dans le prolongement de l'axe A commun à la sousverse 15 et à l'élément tubulaire 12 alors que son extrémité inférieure s'étire jusqu'en proximité de la paroi intérieure de l'élément tubulaire 12. Dans une variante de ce mode de réalisation, il pourra être prévu de ne pas mettre en œuvre un tel organe de dispersion. Ce sera notamment le cas lorsque la sousverse 15 de l'hydrocyclone sera conçue de manière à permettre une projection des grains de ballast contre les parois intérieures tel que cela est représenté par les flèches P. Un dispositif d'enrobage selon l'invention peut être solidarisé directement à un hydrocyclone par la mise en œuvre de tout moyen de fixation adapté comme cela apparaît plus clairement sur la figure 2.The second tubular element 19 is traversed in an upper part by air inlets 24 and has an inlet 25 in a lower portion of the supply 18 which cooperates with polymer supply means (not shown). The coating device 10 according to the invention also comprises means for projecting the ballast grains 28 onto the polymer 26 which flows on the inner wall of the tubular element 12. These projection means comprise a dispersion member of the grains against the inner surface of the tubular element 12. This dispersion member here takes the form of a cup 27 defining a cone placed at the outlet of the underflow 15 of the hydrocyclone 16. The tip of this cup 27 extends in the extension of the axis A common to the underflow 15 and to the tubular element 12 while its lower end extends to near the inner wall of the tubular element 12. In a variant of this embodiment of realization, it may be provided not to implement such a dispersion member. This will be particularly the case when the underflow 15 of the hydrocyclone will be designed to allow a projection of the ballast grains against the inner walls as represented by the arrows P. A coating device according to the invention may be solidarisé directly to a hydrocyclone by the implementation of any suitable attachment means as it appears more clearly in Figure 2.
7.3. Exemple de mise en œuvre d'un dispositif d'enrobage selon l'invention au sein d'une installation de traitement d'eau par floculation lestée7.3. Example of Implementation of a Coating Device According to the Invention Within a Weighted Flocculation Water Treatment Plant
Un dispositif d'enrobage selon l'invention est destiné à être mis en œuvre au sein d'une installation de traitement d'eau par floculation lestée telle que celle qui est illustrée à la figure 3.A coating device according to the invention is intended to be implemented within a weighted flocculation water treatment plant such as that illustrated in FIG.
Une installation de ce type comprend des moyens d'arrivée d'une eau préalablement coagulée qui prennent ici la forme d'une canalisation 30. Cette canalisation 30 débouche dans une cuve de maturation 31.An installation of this type comprises means of arrival of a previously coagulated water which here take the form of a pipe 30. This pipe 30 opens into a maturation tank 31.
Dans la cuve de maturation ou de floculation lestée 31, l'eau coagulée est mise en contact avec : un polymère floculant qui est injecté dans cette cuve par la mise en œuvre de moyens d'injection complémentaire comprenant un injecteur 35 ; avec des grains de ballast neuf par la mise en œuvre de moyens d'injectionIn the maturation or weighted flocculation tank 31, the coagulated water is brought into contact with: a flocculant polymer which is injected into this tank by the implementation of complementary injection means comprising an injector 35; with new ballast grains by the implementation of injection means
43, et des grains de ballast recyclés enrobés de polymère floculant 39.43, and recycled ballast grains coated with flocculating polymer 39.
Pour cela, l'installation comprend également un hydrocyclone 16 dont la sousverse est reliée à l'entrée d'un dispositif d'enrobage 10 selon l'invention de manière à permettre l'injection de grains de ballast enrobés de polymère floculant dans la cuve de maturation 31.For this, the installation also comprises a hydrocyclone 16 whose underflow is connected to the inlet of a coating device 10 according to the invention so as to allow the injection of ballast grains coated with flocculant polymer in the tank maturation 31.
À l'intérieur de la cuve de maturation 31 , les particules colloïdales en présence dans l'eau s'unissent pour former des flocs autour des grains de ballast. La cuve de maturation 31 est séparée d'un décanteur 32 au moyen d'une paroi 40. Elle communique en partie haute de cette paroi 40 avec ce décanteur 32 en sorte que l'eau coagulée et floculée y transite de manière à séparer la phase liquide de la phase solide par décantation des flocs lestés. La surverse 34 du décanteur 32 permet l'évacuation d'une eau traitée alors que la sousverse du décanteur 32 permet l'évacuation d'un mélange de ballast et de boues résultant du traitement de l'eau par floculation lestée.Inside the ripening tank 31, the colloidal particles in the presence of water unite to form flocs around the ballast grains. The maturation tank 31 is separated from a decanter 32 by means of a wall 40. It communicates in the upper part of this wall 40 with the decanter 32 so that the coagulated and flocculated water passes therethrough so as to separate the phase liquid from the solid phase by settling the ballasted flocs. The overflow 34 of the clarifier 32 allows the evacuation of a treated water while the underflow of the decanter 32 allows the evacuation of a mixture of ballast and sludge resulting from the treatment of water by weighted flocculation.
L'eau traitée est évacuée en direction d'une zone de polissage qui comprend un dispositif de fïltration 38.The treated water is discharged towards a polishing zone which comprises a filtration device 38.
Les boues sont quant à elles acheminées via une canalisation 33 reliée à la souverse du décanteur 32 à l'entrée de l'hydrocyclone 16. La mise en œuvre de l'hydrocyclone 16 permet de séparer les boues du ballast : un mélange de boue/ballast faiblement chargé en ballast évacué en surverse est en partie dirigé vers une zone de traitement des boues au moyen d'une canalisation 36 et en partie recyclé vers la cuve de maturation 31 ou en amont de celle-ci au moyen d'une canalisation 37 ; un mélange ballast/boue faiblement chargé en boue évacué en sousverse est dirigé vers l'entrée du dispositif d'enrobage selon l'invention 10.The sludge is conveyed via a pipe 33 connected to the trencher of the decanter 32 at the inlet of the hydrocyclone 16. The implementation of the hydrocyclone 16 separates the sludge from the ballast: a mixture of sludge / The lightly loaded ballast ballast discharged in overflow is partly directed to a sludge treatment zone by means of a pipe 36 and partly recycled to the maturation tank 31 or upstream thereof by means of a pipe 37 ; a ballast / sludge mixture slightly loaded with sludge discharged underflow is directed towards the inlet of the coating device according to the invention 10.
Le ballast recyclé est alors enrobé avec du polymère floculant à l'intérieur du dispositif d'enrobage 10 avant d'être injecté dans la cuve de maturation 31. Selon une variante, les moyens complémentaires d'injection de polymère floculant présentent une autre forme que celle de l'injecteur 35. Dans ce cas, comme cela est représenté sur la figure 4, la cuve de maturation 31 et le décanteur 32 communiquent en partie haute et en partie basse de la paroi 40, un espace 41 étant ménagé entre la partie inférieure de cette paroi 40 et le fond de la cuve de maturation 31. Les moyens complémentaires d'injection comprennent un tube perforé 42 qui s'étend le long de l'espace 41 et qui est logé dans le décanteur 32. Les perforations traversant ce tube 42 présentent avantageusement un diamètre égale au 1/10 du diamètre du tube 42. La mise en œuvre de tels moyens complémentaires d'injection de polymère floculant favorise sa dispersion à l'intérieur de l'installation et augmente en conséquence les performances d'un procédé selon l'invention.The recycled ballast is then coated with flocculant polymer inside the coating device 10 before being injected into the maturation tank 31. According to a variant, the complementary polymer injection means flocculent have a shape other than that of the injector 35. In this case, as shown in FIG. 4, the maturation tank 31 and the decanter 32 communicate in the upper part and in the lower part of the wall 40, a space 41 being formed between the lower part of this wall 40 and the bottom of the maturation tank 31. The complementary injection means comprise a perforated tube 42 which extends along the space 41 and which is housed in the decanter 32. The perforations passing through this tube 42 advantageously have a diameter equal to 1/10 of the diameter of the tube 42. The implementation of such complementary flocculant polymer injection means promotes its dispersion inside the installation and increases accordingly the performance of a method according to the invention.
Dans une autre variante (non représentée), il peut être prévu que la cuve de maturation 31 soit remplacée par une cuve de mise en contact de l'eau avec le polymère floculant et avec le ballast, laquelle est suivie d'une cuve de floculation. La cuve de mise en contact et la cuve de floculation sont séparées par une paroi similaire à la paroi 40, un espace étant ménagé entre le fond des cuves de maturation et de floculation et la partie inférieure de la paroi 40. Dans cette variante, les moyens d'injection complémentaires de polymère pourront prendre la forme d'un tube perforé similaire au tube 42 qui sera placé en regard de l'espace ménagé en partie inférieur de la paroi. Il peut également être prévu que la cuve de floculation loge un agitateur entouré par un élément tubulaire formant un guide flux. Le tube perforé 42 sera alors placé à proximité de l'agitateur.In another variant (not shown), it can be expected that the curing tank 31 is replaced by a tank for contacting the water with the flocculating polymer and with the ballast, which is followed by a flocculation tank . The contacting tank and the flocculation tank are separated by a wall similar to the wall 40, a space being provided between the bottom of the maturation and flocculation tanks and the lower part of the wall 40. In this variant, the additional injection means of polymer may take the form of a perforated tube similar to the tube 42 which will be placed opposite the space formed in the lower part of the wall. It can also be provided that the flocculation tank houses an agitator surrounded by a tubular element forming a flow guide. The perforated tube 42 will then be placed near the stirrer.
7.4. Fonctionnement d'un dispositif d'enrobage selon l'invention Le fonctionnement d'un dispositif d'enrobage selon l'invention va maintenant être décrit en relation avec la figure 1.7.4. Operation of a coating device according to the invention The operation of a coating device according to the invention will now be described in relation with FIG.
Un polymère floculant à l'état liquide est injecté à l'intérieur de la réserve 18 par la mise en œuvre de moyens d'alimentation reliés à l'entrée 25 de la réserve 18.A flocculant polymer in the liquid state is injected inside the reserve 18 by the implementation of feed means connected to the inlet 25 of the reserve 18.
Le polymère à l'état liquide est constitué par une solution mère contenant de 1 à 3 g de polymère par litre. Cette solution mère est elle-même diluée par un facteur de dilution compris entre 1 et 10 (c'est-à-dire qu'un litre de solution mère est diluée dans 1 à 10 litres d'eau). La dilution du polymère permet de faciliter sa répartition à l'intérieur de l'installation et d'augmenter les performances du système. Ceci permet de limiter le dosage du polymère. La diminution du dosage du polymère permet : de limiter la consommation en polymère et donc de réduire les coûts d'exploitation d'une installation de traitement ; de limiter la quantité de polymère résiduel présent dans l'eau traitée en sortie de l'installation, ce qui permet de limiter son impact sur les traitements placés en aval de l'installation. En particulier, s'il est prévu de mettre en œuvre, en aval de l'installation, un traitement complémentaire de fîltration, les membranes mises en œuvre à cet effet seront moins sujettes au colmatage et leur durée de fîltration sera augmentée.The polymer in the liquid state consists of a stock solution containing from 1 to 3 g of polymer per liter. This mother solution is itself diluted by a dilution factor between 1 and 10 (ie one liter of stock solution is diluted in 1 to 10 liters of water). The dilution of the polymer facilitates its distribution within the installation and increases the performance of the system. This makes it possible to limit the dosage of the polymer. The reduction of the polymer dosage makes it possible: to limit the polymer consumption and thus to reduce the operating costs of a treatment plant; to limit the amount of residual polymer present in the treated water at the outlet of the installation, which limits its impact on the treatments placed downstream of the installation. In particular, if it is planned to implement a further filtration treatment downstream of the installation, the membranes used for this purpose will be less prone to clogging and their filtration time will be increased.
Après que la réserve 18 est remplie de polymère à l'état liquide, celui-ci traverse les lumières 17 et se répand sur la paroi intérieure de l'élément tubulaire 12.After the reserve 18 is filled with polymer in the liquid state, it passes through the slots 17 and spreads on the inner wall of the tubular element 12.
Dans le même temps, la sousverse de l'hydrocy clone est déversée dans l'enceinte 11 définie par l'intérieur de l'élément tubulaire 12.At the same time, the underflow of the hydrocyclone is poured into the chamber 11 defined by the interior of the tubular element 12.
Les grains de ballast 28 provenant de la sousverse 15 s'écoulent sur l'organe de dispersion 27 de manière telle qu'ils sont projetés sur le polymère 26 comme cela est représenté par les flèches P.The ballast grains 28 from the underflow flow over the dispersing member 27 so that they are projected onto the polymer 26 as shown by the arrows P.
Les grains de ballast projetés sur le polymère se recouvrent de polymère et s'écoulent par gravité en se déplaçant le long de la surface intérieure recouverte de caoutchouc 13. L'écoulement par gravité est favorisé par les entrées d'air 24 ménagées dans la partie supérieure du deuxième élément tubulaire 19.The ballast grains projected on the polymer are covered with polymer and flow by gravity while moving along the inner surface covered with rubber 13. The flow by gravity is favored by the air inlets 24 formed in the part upper part of the second tubular element 19.
Les grains de ballast enrobés 29 s'écoulent en dehors du dispositif d'enrobage par la périphérie de l'élément tubulaire 12 d'une manière équivalent à l'écoulement de gouttes d'eau depuis les rebords d'un parapluie, ce qui facilite leur dispersion à l'intérieur de la cuve de maturation 31. Le polymère mis en œuvre sera préférentiellement de type : anionique à charge forte dans le cas du traitement d'une eau fortement minéralisée ; anionique à charge plus faible dans le cas du traitement d'une eau chargée en MES et dont l'alcalinité est supérieure à 5° français noté TAC ; - cationique ou anionique très peu chargé dans le cas du traitement d'une eau douce ou très douce chargée en colloïdes.The coated ballast grains 29 flow outside the coating device by the periphery of the tubular element 12 in a manner equivalent to the flow of drops of water from the edges of an umbrella, which facilitates their dispersion inside the maturation tank 31. The polymer used will preferably be of type: strongly charged anionic in the case of treatment of highly mineralized water; anionic charge lower in the case of the treatment of a water loaded with MES and whose alkalinity is greater than 5 ° French noted TAC; - Cationic or anionic with very little charge in the case of the treatment of a soft or very fresh water loaded with colloids.
7.5. Essais7.5. testing
Des essais, dont les résultats sont regroupés dans le tableau 1, ont été réalisés de manière à attester de l'efficacité de la mise en œuvre d'une technique d'enrobage selon l'invention.Tests, the results of which are summarized in Table 1, were carried out in such a way as to show the effectiveness of the implementation of a coating technique according to the invention.
Une première série d'essais a consistée à mesurer la durée de fîltration de filtres placés en aval d'une installation de traitement d'eau par floculation lestée dans laquelle le polymère floculant était injecté directement dans la cuve de maturation sans mise en œuvre d'un dispositif d'enrobage selon l'invention. Une deuxième série d'essais a consistée à mesurer la durée de fîltration de filtres placés en aval d'une installation de traitement d'eau par floculation lestée mettant en œuvre un dispositif d'enrobage selon l'invention et dans laquelle le polymère floculant (en l'occurrence du AN905 : polymère anionique acrylamide commercialisé par la société Floerger) était injecté en deux points : - 50% du polymère était injecté de manière classique directement au sein de la cuve de maturation ou dans le décanteur par la mise en œuvre des moyens d'injection complémentaires ;A first series of tests consisted in measuring the filtration time of filters placed downstream of a weighted flocculation water treatment plant in which the flocculant polymer was injected directly into the maturation tank without the use of a coating device according to the invention. A second series of tests consisted in measuring the filtration time of filters placed downstream of a weighted flocculation water treatment plant implementing a coating device according to the invention and in which the flocculating polymer ( in this case AN905: anionic acrylamide polymer marketed by the company Floerger) was injected at two points: - 50% of the polymer was injected in a conventional manner directly into the maturation tank or into the decanter by the implementation of complementary injection means;
50% du polymère était injecté sous la forme de grains de ballast enrobés au moyen d'un dispositif selon l'invention. Tableau 1 : durées de fïltration de dispositifs de fïltration avals avec ou sans enrobage50% of the polymer was injected in the form of ballast grains coated by means of a device according to the invention. Table 1: Filtering times of aval filtration devices with or without coating
Figure imgf000017_0001
Figure imgf000017_0001
Ces résultats montrent que la durée de fïltration moyenne d'un dispositif de filtration placé en aval est égale à 18 heures lorsque l'ensemble du polymère est injecté de manière classique dans la cuve de maturation. Lorsque le polymère est injecté pour moitié de manière classique et pour moitié sous la forme de grains de ballast enrobés, la durée de fïltration moyenne d'un dispositif de fïltration placé en aval devient égale à 29 heures.These results show that the average filtration time of a downstream filtration device is equal to 18 hours when all of the polymer is injected in the conventional manner in the maturation tank. When the polymer is half injected in a conventional manner and half in the form of coated ballast grains, the average filtration time of a filtration device placed downstream becomes equal to 29 hours.
Les figures 5 et 6 sont des courbes qui illustrent les résultats d'autres essais.Figures 5 and 6 are curves that illustrate the results of other tests.
La figure 5 illustre la durée de fïltration d'un dispositif de fïltration placé en aval d'une installation selon l'invention respectivement avec une injection en un point de manière classique de polymères AN 923 et WT 652.FIG. 5 illustrates the filtration time of a filtration device placed downstream of an installation according to the invention respectively with a one-point injection of polymers AN 923 and WT 652 in a conventional manner.
La figure 6 illustre la durée de fïltration d'un dispositif de fïltration placé en aval d'une installation selon l'invention respectivement avec une injection en était injecté en deux points de polymère de polymères AN 923 et WT 652 : 50% du polymère était injecté de manière classique directement au sein de la cuve de maturation ou dans le décanteur par la mise en œuvre des moyens d'injection complémentaires ;FIG. 6 illustrates the filtration time of a filtration device placed downstream from an installation according to the invention respectively with an injection injected into two polymer polymer points AN 923 and WT 652: 50% of the polymer was injected in a conventional manner directly into the maturation tank or into the decanter by the implementation of the complementary injection means;
50% du polymère était injecté sous la forme de grains de ballast enrobés au moyen d'un dispositif selon l'invention.50% of the polymer was injected in the form of ballast grains coated by means of a device according to the invention.
Ces résultats montrent que la durée de fîltration moyenne d'un dispositif de fîltration placé en aval est égale à environ 17,5 heures lorsque l'ensemble du polymère AN 923 est injecté de manière classique dans la cuve de maturation. Lorsque le polymère AN 923 est injecté pour moitié de manière classique et pour moitié sous la forme de grains de ballast enrobés, la durée de fîltration moyenne d'un dispositif de fîltration placé en aval devient environ égale à 29 heures.These results show that the average filtration time of a downstream filtration device is about 17.5 hours when all of the AN 923 polymer is conventionally injected into the curing pan. When the AN 923 polymer is half injected in conventional manner and half in the form of coated ballast grains, the average filtration time of a downstream filtration device becomes about 29 hours.
Ces résultats montrent également que la durée de fîltration moyenne d'un dispositif de fîltration placé en aval est égale à environ 15 heures lorsque l'ensemble du polymère WT 652 est injecté de manière classique dans la cuve de maturation. Lorsque le polymère WT 652 est injecté pour moitié de manière classique et pour moitié sous la forme de grains de ballast enrobés, la durée de fîltration moyenne d'un dispositif de fîltration placé en aval devient environ égale à 23 heures.These results also show that the average filtration time of a downstream filtration device is about 15 hours when all of the WT 652 polymer is conventionally injected into the curing pan. When the WT 652 polymer is half injected in a conventional manner and half in the form of coated ballast grains, the average filtration time of a downstream filtration device becomes approximately 23 hours.
La mise en œuvre de l'invention permet donc d'accroître de 50 à plus de 60% la durée de filtration d'un dispositif de filtration placé en aval d'une installation de traitement d'eau par floculation lestée.The implementation of the invention therefore makes it possible to increase from 50 to more than 60% the filtration time of a filtration device placed downstream of a weighted flocculation water treatment installation.
Par ailleurs, la mise en œuvre de la technique selon l'invention permet de réduire de 20 à 30% la consommation en polymère floculant nécessaire au traitement de l'eau. 7.6. AvantagesMoreover, the implementation of the technique according to the invention makes it possible to reduce by 20 to 30% the consumption of flocculant polymer necessary for the treatment of water. 7.6. Advantages
La mise en œuvre d'une technique d'enrobage selon l'invention procure donc plusieurs avantages.The implementation of a coating technique according to the invention therefore provides several advantages.
Notamment, elle permet d'optimiser la maturation du fait qu'une partie du polymère floculant se présente sous la forme d'un enrobage des grains de ballast favorisant l'agglomération des particules colloïdales directement autour des grains de ballast et réduisant en conséquence la concentration en particules de l'eau traitée par floculation lestée.In particular, it makes it possible to optimize the maturation process because part of the flocculant polymer is in the form of a coating of the ballast grains, favoring the agglomeration of the colloidal particles directly around the grains. of ballast and consequently reducing the particle concentration of the treated water by weighted flocculation.
Elle permet, du faite de la meilleure utilisation du polymère floculant qu'elle autorise, de réduire la quantité de polymère nécessaire au traitement. Elle permet également d'accroître la durée de fïltration des dispositifs de fîltration placés en aval des installations de traitement d'eau par floculation lestée ce qui conduit à réduire le coût du traitement de l'eau. En effet, la mise en œuvre de la technique selon l'invention permet de réduire la quantité de polymère floculant injecté dans l'eau et donc de limiter les surdosages en polymère, lesquels ont pour conséquence d'augmenter le colmatage des membranes placées en aval.It makes it possible, by virtue of the best use of the flocculating polymer that it allows, to reduce the amount of polymer necessary for the treatment. It also makes it possible to increase the filtration time of the filtration devices placed downstream of the water treatment plants by weighted flocculation, which leads to a reduction in the cost of water treatment. Indeed, the implementation of the technique according to the invention makes it possible to reduce the quantity of flocculant polymer injected into the water and thus to limit the polymer overdoses, which have the consequence of increasing the clogging of the membranes placed downstream. .
La mise en œuvre de la technique selon l'invention permet ainsi l'obtention d'une eau clarifiée de qualité équivalente à celle d'une eau traitée par flottation ou sans apport de polymère et dont le pouvoir colmatant est inférieur à celui d'une eau traitée classiquement avec injection de polymère floculant. En d'autres termes, la mise en œuvre de la technique selon l'invention permet de bénéficier des avantages liés à l'utilisation de polymère floculant (rapidité de traitement, facilité de mise en œuvre...) sans en subir les inconvénients (colmatage des membranes placées en aval). The implementation of the technique according to the invention thus makes it possible to obtain a clarified water of equivalent quality to that of a water treated by flotation or without the addition of a polymer and whose clogging power is lower than that of a conventionally treated water with flocculant polymer injection. In other words, the implementation of the technique according to the invention makes it possible to benefit from the advantages associated with the use of flocculating polymer (speed of treatment, ease of implementation, etc.) without suffering the disadvantages thereof ( clogging downstream membranes).

Claims

REVENDICATIONS
1. Dispositif d'enrobage (10) avec un matériau polymère floculant à l'état liquide de grains de ballast (28) utilisés pour le traitement de l'eau par floculation lestée, ledit dispositif (10) comprenant une chambre (11), des moyens d'introduction (14) desdits grains (28) dans ladite chambre (11), des moyens d'injection (17) dudit polymère à l'état liquide dans ladite chambre (11), des moyens de mise en contact desdits grains (28) et dudit polymère (26) à l'état liquide, et des moyens de décharge de grains enrobés dudit polymère (29) en périphérie de ladite chambre (11) caractérisé en ce que lesdits moyens d'introduction comprennent une ouverture (14) destinée à coopérer avec la sousverse (15) d'un hydrocyclone (16) et en ce que lesdits moyens d'injection comprennent des moyens d'écoulement dudit polymère à la périphérie intérieure de ladite chambre (11) et des moyens de projection desdits grains (28) sur ledit polymère (26). Apparatus for coating (10) with a flocculant polymer material in the liquid state of ballast grains (28) used for the treatment of water by weighted flocculation, said device (10) comprising a chamber (11), means for introducing (14) said grains (28) into said chamber (11), injection means (17) for said polymer in the liquid state in said chamber (11), means for contacting said grains (28) and said polymer (26) in the liquid state, and coated grain discharge means of said polymer (29) at the periphery of said chamber (11) characterized in that said introducing means comprises an opening (14). ) intended to cooperate with the underflow (15) of a hydrocyclone (16) and in that said injection means comprise flow means for said polymer at the inner periphery of said chamber (11) and means for projecting said grains (28) on said polymer (26).
2. Dispositif d'enrobage selon la revendication 1, caractérisé en ce que lesdits moyens de projection comprennent un organe de dispersion (27) desdits grains (28) en direction dudit polymère (26) ou de la périphérie intérieure de ladite chambre (11), ledit organe de dispersion (27) étant placé en regard desdits moyens d'introduction (14). 2. Coating device according to claim 1, characterized in that said projection means comprise a dispersing member (27) of said grains (28) towards said polymer (26) or the inner periphery of said chamber (11) , said dispersion member (27) being placed opposite said insertion means (14).
3. Dispositif d'enrobage selon l'une quelconque des revendications 1 ou 2, caractérisé en ce qu'il comprend un élément essentiellement tubulaire (12) concentrique par rapport auxdits moyens d'introduction (14) desdits grains (28), lesdits moyens d'écoulement étant formés par une pluralité de lumières (17) ménagées à la périphérie dudit élément tubulaire (12). 3. Coating device according to any one of claims 1 or 2, characterized in that it comprises a substantially tubular element (12) concentric with respect to said means (14) for introducing said grains (28), said means flow path being formed by a plurality of lumens (17) formed at the periphery of said tubular member (12).
4. Dispositif d'enrobage selon la revendication 3, caractérisé en ce que la surface intérieure dudit élément tubulaire (12) est au moins en partie recouverte par un matériau anti-adhérant (13).4. Coating device according to claim 3, characterized in that the inner surface of said tubular element (12) is at least partly covered by a release material (13).
5. Dispositif d'enrobage selon la revendication 4, caractérisé en ce que ledit matériau anti-adhérant (13) est constitué par du caoutchouc. 5. Coating device according to claim 4, characterized in that said release material (13) consists of rubber.
6. Dispositif d'enrobage selon l'une quelconque des revendications 1 à 5, caractérisé en ce qu'il comprend une enceinte (23) formant une réserve (18) dudit polymère, ladite réserve (18) présentant une entrée (25) coopérant avec des moyens d'alimentation en polymère et une sortie coopérant avec lesdits moyens d'injection (17). 6. Coating device according to any one of claims 1 to 5, characterized in that it comprises an enclosure (23) forming a reserve (18) of said polymer, said reserve (18) having an inlet (25) cooperating with polymer supply means and an outlet cooperating with said means for injection (17).
7. Dispositif d'enrobage selon l'une quelconque des revendications 1 à 6, caractérisé en ce que ladite enceinte (23) présente au moins une entrée d'air (24).7. Coating device according to any one of claims 1 to 6, characterized in that said enclosure (23) has at least one air inlet (24).
8. Installation de traitement d'eau comprenant une cuve de floculation lestée (31), un décanteur (32) qui communique avec ladite cuve de floculation (32), un hydrocyclone (16) présentant une souverse et dont l'entrée est reliée à la sousverse (33) du décanteur (32), caractérisée en ce qu'elle comprend un dispositif d'enrobage (10) avec un matériau polymère floculant à l'état liquide de grains de ballast (28) utilisés pour le traitement de l'eau par floculation lestée selon l'une quelconque des revendications 1 à 7, ledit dispositif (10) comprenant une chambre (11), des moyens d'introduction (14) desdits grains (28) dans ladite chambre (1 1), des moyens d'injection (17) dudit polymère à l'état liquide dans ladite chambre (11), des moyens de mise en contact desdits grains (28) et dudit polymère (26) à l'état liquide, et des moyens de décharge de grains enrobés dudit polymère (29) en périphérie de ladite chambre (11), lesdits moyens d'introduction comprenant une ouverture destinée à coopérer avec ladite souverse dudit hydrocyclone (16), et lesdits moyens de décharge débouchant dans ladite cuve de floculation lestée (39).8. A water treatment plant comprising a weighted flocculation tank (31), a decanter (32) which communicates with said flocculation tank (32), a hydrocyclone (16) having a gate and whose input is connected to the underflow (33) of the clarifier (32), characterized in that it comprises a coating device (10) with a flocculant polymer material in the liquid state of ballast grains (28) used for the treatment of the weighted flocculation water according to any one of claims 1 to 7, said device (10) comprising a chamber (11), means (14) for introducing said grains (28) into said chamber (1 1), means injecting (17) said polymer in the liquid state into said chamber (11), means for contacting said grains (28) and said polymer (26) in the liquid state, and grain discharging means coated with said polymer (29) at the periphery of said chamber (11), said introducing means comprising a opening for cooperating with said recess of said hydrocyclone (16), and said discharge means opening into said weighted flocculation vessel (39).
9. Installation selon la revendication 8, caractérisé en ce qu'elle comprend des moyens complémentaires d'injection (35, 42) dudit matériau polymère floculant. 9. Installation according to claim 8, characterized in that it comprises complementary injection means (35, 42) of said flocculant polymer material.
10. Installation selon la revendication 9, caractérisé en ce que ladite cuve de floculation lestée (31) et ledit décanteur (32) sont séparés par une paroi (40), ladite cuve de floculation lestée (31) et ledit décanteur (32) communiquant en partie supérieure et en partie inférieure de ladite paroi (40), lesdits moyens d'injection complémentaires comprenant un tube perforé (42) longeant la partie inférieure de ladite paroi (40). 10. Installation according to claim 9, characterized in that said weighted flocculation tank (31) and said decanter (32) are separated by a wall (40), said weighted flocculation tank (31) and said decanter (32) communicating. in the upper part and in the lower part of said wall (40), said complementary injection means comprising a perforated tube (42) running along the lower part of said wall (40).
PCT/EP2010/050534 2009-01-19 2010-01-18 Device for coating with a flocculating polymer material in the liquid state of ballast particles used for the treatment of water by ballasted flocculation, and corresponding facility WO2010081903A1 (en)

Applications Claiming Priority (2)

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FR0950284 2009-01-19
FR0950284A FR2941225B1 (en) 2009-01-19 2009-01-19 COATING DEVICE WITH FLOCCULATING POLYMERIC MATERIAL IN THE LIQUID CONDITION OF BALLAST GRAINS USED FOR THE TREATMENT OF WATER BY FLOCCULATING THE SAME, AND CORRESPONDING INSTALLATION.

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US8470172B2 (en) 2007-01-09 2013-06-25 Siemens Industry, Inc. System for enhancing a wastewater treatment process
US8540877B2 (en) 2007-01-09 2013-09-24 Siemens Water Technologies Llc Ballasted sequencing batch reactor system and method for treating wastewater
US8623205B2 (en) 2007-01-09 2014-01-07 Siemens Water Technologies Llc Ballasted anaerobic system
US8840786B2 (en) 2007-01-09 2014-09-23 Evoqua Water Technologies Llc System and method for removing dissolved contaminants, particulate contaminants, and oil contaminants from industrial waste water
US9651523B2 (en) 2012-09-26 2017-05-16 Evoqua Water Technologies Llc System for measuring the concentration of magnetic ballast in a slurry
US10919792B2 (en) 2012-06-11 2021-02-16 Evoqua Water Technologies Llc Treatment using fixed film processes and ballasted settling

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Cited By (11)

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Publication number Priority date Publication date Assignee Title
US8470172B2 (en) 2007-01-09 2013-06-25 Siemens Industry, Inc. System for enhancing a wastewater treatment process
US8506800B2 (en) 2007-01-09 2013-08-13 Siemens Industry, Inc. System for enhancing a wastewater treatment process
US8540877B2 (en) 2007-01-09 2013-09-24 Siemens Water Technologies Llc Ballasted sequencing batch reactor system and method for treating wastewater
US8623205B2 (en) 2007-01-09 2014-01-07 Siemens Water Technologies Llc Ballasted anaerobic system
US8673142B2 (en) 2007-01-09 2014-03-18 Siemens Water Technologies Llc System for enhancing a wastewater treatment process
US8702987B2 (en) 2007-01-09 2014-04-22 Evoqua Water Technologies Llc Methods for enhancing a wastewater treatment process
US8840786B2 (en) 2007-01-09 2014-09-23 Evoqua Water Technologies Llc System and method for removing dissolved contaminants, particulate contaminants, and oil contaminants from industrial waste water
US8845901B2 (en) 2007-01-09 2014-09-30 Evoqua Water Technologies Llc Ballasted anaerobic method for treating wastewater
US10023486B2 (en) 2007-01-09 2018-07-17 Evoqua Water Technologies Llc Ballasted sequencing batch reactor system and method for treating wastewater
US10919792B2 (en) 2012-06-11 2021-02-16 Evoqua Water Technologies Llc Treatment using fixed film processes and ballasted settling
US9651523B2 (en) 2012-09-26 2017-05-16 Evoqua Water Technologies Llc System for measuring the concentration of magnetic ballast in a slurry

Also Published As

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FR2941225B1 (en) 2012-08-31
FR2941225A1 (en) 2010-07-23

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