FR2716391A1 - Physical treatment of a fluid contg. solids such as mud or silt - Google Patents

Abstract

A process and appts. are claimed for treatment of a fluid contg. mud and silt etc. The fluid (2) is extracted (3) and physically treated (6) to separate solids over a given size, before further physical and chemical treatment (4). Fluid and solids are discharged separately from the installation.

Description

INSTALLATION AND METHOD FOR THE CLEAN TREATMENT OF FLUIDS
LOADS IN E! 1KRTICLES, SUCH AS SLUDGE OR ESTES.

The present invention relates to an installation as well as to a process for the clean treatment of fluids loaded with particles such as solids, sands, pollutants, organic waste or the like.

Such installations are known and in particular from FR-A-2,607,080, of the type comprising an extraction capable of conveying the charged fluid to a treatment system which makes it possible to reject at the outlet of the installation the particles at least partially separated. of the fluid itself.

For example, the loaded fluid can be extracted by a suction dredge or pumped directly, in the case of industrial sludge. Also, the fluids to be treated can be conveyed by simple sealed pipes.

Many physico-chemical treatment systems have been described, among others in FR-C-77.14196 (Utility certificate) or more recently in FR-92.14.392. These systems are designed to dehydrate the suspended matter in the fluid, most often water, and to concentrate these matters or charges, until products capable of being discharged are obtained, generally in a classified landfill.

These elements known to those skilled in the art are therefore not to be described further.

The installations and similarly the methods of the prior art have major drawbacks.

Primarily, the dryness of the products obtained is too great for them to be easily transported or reused. Similarly, when the fluid is like in most cases water, its filler content is higher than the standards allowing its rejection in a natural environment.

In addition, and with the same objective of protecting the environment, known installations which are heavy, bulky and / or insufficiently confined, generally alter or pollute the place where they are located. In fact, interventions on a drinking water plan, for example, should be avoided. The use of known installations generates other nuisances, both noise and chemical, or even at their place of use.

One of the objects of the present invention is to alleviate, among other things, the above drawbacks, by making rapid, clean -or ecological interventions possible and allowing discharges directly into a natural environment, or at least avoiding their use. controlled discharge. In addition, the invention is modular, flexible and economical to implement and capable of accomplishing missions hitherto almost impracticable.

To this end, one of the objects of the invention is an installation for treating fluids loaded with particles, such as sludge, vases or the like, and of the type comprising an extraction capable of conveying a loaded fluid to a treatment system which at least partially isolates the particles from the fluid proper, characterized in that the treatment system comprises, upstream of a physicochemical device for concentration and dehydration according to the direction of circulation of the charged fluid, an assembly capable of physically separating at within the charged fluid particles whose dimension exceeds a predetermined format, in order to be able to reject at the outlet of the installation, on the one hand these particles and on the other hand the fluid itself.

According to one characteristic, the above-mentioned physical separation assembly comprises a so-called Xhydrocyclone swirling enclosure, which is provided with at least one tangential supply under pressure and connected to the extraction, as well as a central overflow, arranged at right angles to 'an outlet cone of particles larger than the aforementioned format and through which the fluid is discharged downstream, once rid of these particles under the effect of the difference of the respective centrifugal forces.

Preferably, the hydrocyclone supply includes a shoe for adjusting the cross-section of the charged fluid, so that the pressure - and proportionally the swirl speed of the latter - can be maintained at a chosen value that is substantially constant.

According to one embodiment, the extraction comprises a floating dredge, provided with an extraction tool and with a double fairing for substantially hermetic confinement of its functional organs, such as a drive motor.

It is advantageous that the aforementioned dredge extraction tool is driven by an electric motor or the like, arranged above the water line of the dredge and connected to this motor by a flexible torque transmission.

In addition, the aforementioned extraction tool and dredger may include removable mutual securing means.

Furthermore, the aforementioned physical separation assembly may comprise at least one grid or sieve, the meshes of which have a size corresponding to the predetermined format, this grid being mounted to travel on the installation and secured to a vibrating system such as a motor. unbalanced, cooperating itself with a frequency converter of the grid vibrations with respect to the installation.

 I1 is advantageous that a box connected to a fan or the like capable of placing this box under vacuum, is arranged in line with at least one aforementioned grid.

In this case, provision may be made for at least one grid of the above-mentioned assembly to be arranged at an inclination of the order of 60 or more, and / or to be mounted on the installation by means of a mechanism adjustment of its inclination.

In addition, it is conceivable that at least one aforementioned grid comprises a polyurethane anti-clogging structure, and / or a washing system by spraying a fluid under high pressure.

According to one embodiment, at least one aforementioned grid called "upstream" has meshes of the order of 5mm, while at least one other so-called Savais has meshes of the order of 50 to 60 Fm .

In certain applications, one or more of the elements of the installation such as extraction, isolation assembly, physico-chemical treatment device, are arranged independently - or by functional groups - and on a transportable support.

Another subject of the invention relates to a process for treating fluids loaded with particles, such as sludge, vases or the like, and of the type comprising the steps consisting in: extracting and conveying the loaded fluid to a treatment system; treating said fluid by at least partially isolating said particles, characterized in that it comprises, upstream of a stage of concentration and of physicochemical dehydration of the charged fluid according to its direction of circulation, a treatment stage consisting of physically separate particles whose size exceeds a predetermined format, in order to be able to reject on leaving the installation, on the one hand these particles and on the other hand the fluid proper.

Alternatively, there is provided a process for treating fluids loaded with particles, characterized in that it is carried out by an installation as defined above.

But other advantages and features of the present invention will become more apparent from the detailed description which follows and refers to the accompanying drawings, in which.

Figure 1 is a schematic view of a
installation according to the invention;
Figure 2 is a perspective view from behind
a dredge corresponding to the detail indicated in II
in Figure 1;
Figure 3 is a schematic sectional view of a
detail shown in III in Figure 1;
Figure 4 is a partial view in section of a
hydrocyclone with feed adjustment shoe,
corresponding to the detail indicated in IV on the figure
3;
Figure 5 is a partial sectional view
transverse along line VV of Figure 4; and
Figure 6 is an elevational view of a grid
vibrating with vacuum chamber, corresponding
in detail shown in VI in Figure 3.

In the figures, the general reference numeral 1 designates a treatment or purification installation. The purpose of this type of installation is to treat mixtures of fluids and various particles, organic residues, pollutants, etc. Although other mixtures can be treated in installation 1, the following non-limiting description is given in relation to the purification of a sludge essentially consisting of water loaded with particles, for example sand, waste, substances organic. This charged fluid is designated in 2, while its direction of circulation within the installation 1, which will be referred to as going symbolically from upstream to downstream, is represented by the arrows S.

Referring to Figure 1, it is understood that the installation 1 comprises from upstream to downstream an extraction 3, capable of conveying the charged fluid 2 to a treatment system 4, which makes it possible to at least partially isolate the particles contained in the fluid itself.

Those skilled in the art will find in the current literature, in particular in the documents mentioned above, the technical specifications of the elements mentioned so far, and which it is therefore not necessary to describe here.

The treatment system 4 comprises, upstream of a physicochemical concentration and dehydration device 5 (lower part of the installation 1 in FIG. 1), an assembly 6 capable of physically separating the particles within the charged fluid 2 whose dimension exceeds a predetermined format, in order to be able to reject at the outlet of the installation 1, on the one hand these particles and on the other hand the fluid itself.

This constitutes one of the major features of the invention, thanks to which it is possible to avoid loading the sludge, or even to revalue it.

The installation 1 and its operating method are therefore designed in an ecological spirit, since for example the waste water can be, after chemical control, directly returned to its natural environment. A clarity of the discharged water less than 5Mg / l of MES, can be obtained with the invention.

The extraction 3 visible in FIGS. 1 and 2 comprises a floating dredge capable of pumping the sludge. The dredge 3 is provided with an extraction tool (not shown) as well as a double fairing for substantially hermetic confinement of its functional members, such as a drive motor. Since all the mechanical elements of dredger 3 (heat engine, hydraulic power plant, generator, fuel tank) are under double containment shroud, the extraction does not affect the environment in which it is used.

The dredge extraction tool 3, the proper structure of which is conventional, has the particularity of being driven by an electric motor or the like 32. The motor 32 is, as can be seen in FIG. 2, arranged at above the waterline 33 of the dredger 3. Thus, although it is not here confined to a double fairing, it does not affect the environment 2.

This motor 32 is connected to the extraction tool by a flexible torque transmission 34, such as a guided metal cable. The extraction tool is therefore driven remotely. Secret tests have shown that an extraction depth of up to 14 meters has been obtained, which is unique for a machine of this category. Furthermore, the tool and the dredger 3 comprise removable mutual securing means. This allows rapid interchangeability of the extraction tool.

Following S in FIG. 1, it can be seen that downstream of the extraction 3, the assembly 6 comprises at least one grid or sieve 7. Each grid 7 comprises meshes whose size corresponds to the predetermined format of the particles that it must sift. Preferably, each grid 7 comprises an anti-clogging structure in polyurethane. the grid 7 on the right in FIG. 3 is provided with a system 71 for washing by spraying a fluid under high pressure. More specifically, this system 71 consists of adding clear water.

We can see in Figure 6, which illustrates in detail a grid 7 similar to that which is equipped with the addition of clear water 71, that it is mounted to travel on the installation 1 and secured to a vibrating system 73 such as an unbalance motor. The motor 73 is fixed to the screen pan 7, the latter being provided with springs 74 capable of damping its movement relative to the installation 1.

This travel is approximately vertical.

By cons, the grid 7 in question is arranged at an inclination a relative to the horizontal, of the order of 60 at most (Figure 3). the grid of FIG. 7 is articulated, for example at its lower left angle, with respect to the installation 1. On the right, that is to say opposite this articulation, we see that the grid 7 is mounted on the installation 1 by means of a mechanism 76 for adjusting its inclination a. Here, the mechanism 76 is a jack, one end of which is fixed to the installation, while the other is secured to the grid 7. When this jack is supplied so that its length varies, the inclination also changes. The reference 75 indicates in the figures of the overflows, emerging at the sight of a grid 7, to supply it with charged fluid 2.

The sieves 7 of Figures 3 (right) and 6 are connected at the outlet to a box 72. The interior of this box is itself in communication with the inlet of a fan motor or the like 77, capable of placing this box under vacuum . By thus placing a vacuum chamber 72 in line with a grid 7, it is possible to improve by about 5 points the dryness of the treated waste, and therefore to reduce pollution in large proportions. Note that the depression in the box 72 is adjustable from 150 to 600 mm of H2O, in order to optimize the suction as a function of the particle size of the particles, such as sand.

It goes without saying that a sieve 7 provided with a vacuum chamber 72 must be placed, just upstream of the device 5, that is to say at the level of a spinning phase of the separated particles. .

As indicated in 8 in FIG. 3, these particles are small manures or sands, the dimensions (or format) of which are greater than 2 mm. It has been observed that the average dryness of the particles from this phase is around 85%, which is about 15 points higher than what is obtained with a traditional installation.

The grid 7 located just downstream of the extraction 3 has the function of carrying out a first sieving or scaling / screening of the loaded fluid 2. This operation makes it possible to remove the largest particles contained in the sludge. According to the example illustrated, this grid has meshes of the order of 5 mm. The unbalance motor 73 which is coupled to this grid 7 cooperates itself with a frequency converter not shown.

This variator makes it possible to adjust the frequency of the vibrations of the grid 7 relative to the installation 1.

This installation is provided so that downstream of the first sieve 7 along S, there is a recovery and treatment of the particles having passed through. For this purpose, the physical separation assembly 6 comprises a swirling enclosure 9 called Shydrocyclone ^. Each hydrocyclone 9 comprises a cylindrical upper part, and a conical coaxial lower part 97. The cone 97 is arranged so that its longitudinal axis
XX 'is substantially vertical, and of course common with the central axis of the cylindrical upper part.

Here, each hydrocyclone 9 is arranged in line with a grid 7.

As is clear from FIGS. 4 and 5, a coaxial tube at XX ′ penetrates via its supply 93 from the top into the hydrocyclone 9, to form a central overflow 95. The overflow 95 is connected, at least indirectly, to the physical- chemical 5, since this is where the least charged fluid escapes along S. It is already understood that the charged fluid penetrating along S into the enclosure 9 swirls approximately around XX '. Then, under the effect of the difference of the centrifugal forces respectively applied to the fluid proper and to the particles which it contains, whose own densities are different, the first will tend to remain closer to X-X ', to be able be captured by the overflow 95, while the second move along the cone 97, away from said overflow. It has been noted that to properly fulfill its role, a hydrocyclone must work at constant pressure. However, pressure, swirl speed and flow are linked.

In FIG. 5, it can be seen that the supply 93 of the cyclone 9 is tangential. In other words, this supply takes place along S in a plane perpendicular to XX ′ and approximately parallel to its cross section. It is further noted that the hydrocyclone 9 comprises a shoe 94 for adjusting the cross section of the charged fluid. I1 is clear from Figure 5 that the shoe can come opposite and hide -and therefore obturertotal or clear the opening through which the supply 93 enters the enclosure 9. By moving along R, that is say in relation to the passage section, the opening of the latter changes.

Here, the movement takes place along a radius centered on X-X ', and the opening or passage is indicated in P.

This opening P can vary up to the value indicated in dotted lines in one direction, or until the supply 93 is completely closed.

Thanks to the shoe 94, even if the flow rate changes, the charged fluid swirling in the hydrocyclone 9 can keep the same speed, and therefore the same pressure. These parameters can thus be maintained at a substantially constant and appropriate value.

Here, the shoe 94 is preferably made of rubber, and it is possible to vary the speed of entry of the flow, for a constant flow rate, from 1.8 to 6 m / s. Thus, the cut-off of the charged fluid can vary, which is very useful in particular for removing organic matter.

 It appears from FIG. 3 that recycling or a loop can be provided downstream of the overflow 95, in particular by means of a receiving tank 17. Still in this figure, the addition of water has been indicated in 91 clear, which makes it possible to "wet" the rejections coming from the cone 97, before it reaches the sieve 7 downstream. Additions 71 and 91 can for example be obtained by connection to a drinking water network.

Since as explained above, particles larger than 5 mm have been eliminated, downstream the hydrocyclone 9 has the function of taking up and treating elements from 5 mm to 20 p. Note that the following transfer of fluids
S in particular, within installation 1, is carried out by recovery and by pumping.

Briefly, it is understood that the method of the invention consists in extracting and conveying a charged fluid to a treatment system 4, in treating said fluid by at least partially isolating said particles. In addition, upstream of the conventional physical and chemical concentration and dehydration step carried out in 5, a preliminary treatment step is carried out which consists in physically separating the particles whose size exceeds a predetermined format. This physical or mechanical separation is taken care of by the specific sieves and hydrocyclones which have just been described.

This allows to be able to reject at the outlet of the installation 1, on the one hand the particles and on the other hand the fluid itself.

According to a preferred embodiment, a first physical separation will be carried out by removing particles larger than 5 mm, and a second downstream will act on particles of the order of 50 to 60 p. The pulp containing the elements below 20 p is taken up by pumping and sent to the physicochemical device 5.

This invention is in no way limited to the embodiment which has just been described, and includes the combinations and equivalents of the technical means illustrated, if these are carried out according to the spirit.

Claims (14)

ResENDIcATIoNs 1- Installation (1) for treating fluids loaded (2) with particles, such as sludge, vases or the like, and of the type comprising an extraction (3) capable of conveying a loaded fluid to a treatment system (4) which allows to at least partially isolate the particles from the fluid proper, characterized in that the treatment system comprises, upstream of a physicochemical device (5) for concentration and dehydration in the direction (S) of circulation of the charged fluid, an assembly (6) capable of physically separating within the charged fluid the particles whose dimension exceeds a predetermined format, in order to be able to reject at the outlet of the installation (1), on the one hand these particles and on the other hand the fluid itself. 2- Installation according to claim 1, characterized in that the assembly (6) of the aforementioned physical separation comprises at least one enclosure (9) of so-called "hydrocyclone" swirling, which is provided with at least one tangential supply (93) under pressure and connected to the extraction, as well as a central overflow, arranged in line with an outlet cone of the particles of dimension larger than the aforementioned format and by which the fluid is evacuated downstream, once rid of these particles under the effect the difference of the respective centrifugal forces. 3- Installation according to claim 2, characterized in that the supply of the hydrocyclone (93) comprises an adjustment shoe (94) of the passage section of the charged fluid, so that the pressure -and proportionally the speed of swirling of the latter can be maintained at a selected value which is substantially constant. 4- Installation according to one of claims 1 to 3, characterized in that the extraction (3) comprises a floating dredge, provided with an extraction tool and a double fairing of substantially hermetic confinement of its functional organs , such as drive motor. 5- Installation according to claim 4, characterized in that the above-mentioned dredger extraction tool (3) is driven by an electric motor (32) or the like, arranged above the waterline (33) of the dredger and connected to this motor by a flexible torque transmission (34). 6- Installation according to one of claims 4 or 5, characterized in that the aforementioned extraction tool and dredge (3) comprise removable means for securing each other. 7- Installation according to one of claims 1 to 6, characterized in that the above assembly (6) of physical separation comprises at least one grid (7) or sieve, whose meshes have a size corresponding to the predetermined format, this grid being mounted to travel on the installation and integral with a vibrating system (73) such as an unbalance motor, itself cooperating with a frequency converter for vibration of the grid with respect to the installation (1). 8- Installation according to claim 7, characterized in that a box (72) connected to a motor-fan (77) or the like capable of placing this box under vacuum, is arranged in line with at least one grid (7) cited above. 9- Installation according to one of claims 7 or 8, characterized in that at least one grid (7) of the above-mentioned assembly (6) of separation, is arranged at an inclination (a) of the order of 60 or more, and / or is mounted on the installation by means of an adjustment mechanism (76) of its inclination. 10- Installation according to one of claims 7 or 9, characterized in that at least one grid (7) above comprises an anti-clogging polyurethane structure, and / or a system (71) for washing by spraying a fluid under high pressure. 11- Installation according to one of claims 7 to 10, characterized in that at least one grid (7) mentioned above called "upstream" has meshes of the order of 5mm, while at least another called "downstream" "has meshes on the order of 50 to 60 m. 12- Installation according to one of claims 1 to 11, characterized in that one or more of its elements such as extraction (3), separation assembly (6), physico-chemical treatment device (5), is arranged independently - or by functional group - and / or on a transportable support. 13- Process for treating fluids loaded (2) with particles, such as sludge, vases or the like, and of the type comprising the steps consisting in: extracting and conveying the loaded fluid to a treatment system (4); treating said fluid by at least partially isolating said particles, characterized in that it comprises, upstream of a stage of concentration and physico-chemical dehydration of the charged fluid according to its direction (S) of circulation, a step of treatment consisting in physically separating particles whose dimension exceeds a predetermined format, in order to be able to reject on leaving the installation (1), on the one hand these particles and on the other hand the fluid proper. 14- Treatment method according to the preceding claim, characterized in that it is carried out by an installation according to one of claims 1 to 12.