FR3077220A1 - MODULE FOR WATER FILTRATION, FILTRATION METHOD, WASHING METHOD AND CORRESPONDING FILTRATION INSTALLATION - Google Patents

Abstract

The present invention relates to a module (1) for water filtration, filtration and washing processes thereof and an installation comprising the module (1). The module (1) comprises an enclosure (10) closed by a lid and at least one filter element (50) with hollow fibers. The enclosure (10) includes a horizontally located top plate (30) and a bottom plate (20) on which there are holes in alignment. The upper end of the filter element (50) is surrounded laterally by a top sheath comprising a collar. The filter element (50) fits at its upper and lower ends into the hole of the upper plate (30) and the hole of the lower plate (20) respectively. The flange of the upper stopper sheath with a lower surface of the upper plate (30).

Description

Module for water filtration, filtration process, washing process and corresponding filtration installation.

1. Field of the invention

The present invention relates to the field of water filtration, in particular the field of microfiltration and ultrafiltration of water, particularly in situations of natural disaster and / or humanitarian crises.

More specifically, the present invention relates to a water filtration module comprising at least one hollow fiber filtration element. The invention also relates to a method of filtering water from the filtration module and a method of washing the filtration module. Finally, the invention also relates to a mobile filtration installation comprising the filtration module.

2. Prior art

Microfiltration and ultrafiltration processes using hollow fiber filtration elements provide water treatment suitable for human consumption, the treated water being free from suspended matter, bacteria and viruses in particular.

A hollow fiber filter element includes a bundle of fibers, hollow and of substantially cylindrical shape, which are permeable to water but block the passage of particles beyond a certain size. Depending on the nature of the hollow fibers used, the water can be microfiltered and / or ultrafiltered.

By convention of a bottom-to-top flow of the water to be treated, a conventional filtration element, of the filtration type from the outside to the inside, generally comprises a bottom end where the fibers are embedded in a block of resin. waterproof and a high end where the fibers emerge from a block of waterproof resin. The water to be treated is introduced outside the fibers and the filtered water is collected at the upper end of the filtration module: the water passes through the walls of the hollow fibers while the particles of a certain size are retained by the walls of the hollow fibers.

Several hollow fiber filtration elements are generally associated in parallel and arranged inside an enclosure comprising a single point of injection of water to be filtered and a single point of recovery of filtered water. The set of hollow fiber filtration elements and the enclosure forms a filtration module.

The water filtration units can be of different sizes. Likewise, these units can be set up permanently or temporarily. The installation method, the size of the units, the type of filtration, the choice of materials and filtration elements will depend on the water needs, the place of delivery, their destination, etc. It is very commonly used in long-term collective networks for the production and distribution of drinking water, especially in urban centers. However, in certain situations, territories and / or populations may have an urgent and temporary need for drinking water. These may, for example, be territories subject to regular or ad hoc health and / or humanitarian crises. It can also be territories, whose usual water treatment infrastructure is at least temporarily out of use, following in particular a natural disaster (cyclone, earthquake, fire, etc.). These situations involve providing filtration modules to local populations and / or teams dedicated to the management of these crises. Many constraints are therefore imposed. Thus, the filtration modules - and the installations incorporating them - must be sufficiently compact in order to be able to be transported easily, by air, sea or road. In particular, the modules must be able to be transported according to the usual standards of air cargo. In addition, the filtration modules must be strong enough to withstand sometimes rough transport conditions. In addition, the filtration modules must be robust and simple to use, in order to be handled (operation, maintenance) without undue difficulty for several months, even several years, by non-experts. Indeed, such filtration modules are generally intended to be deployed in territories where a qualified workforce will sometimes be rare, or even absent, therefore requiring handling of the modules by officials of Non-Governmental Organizations or by local population. Thus, such filtration modules should very preferably be sufficiently compact, simple to use, robust. In addition, the implementation of simple maintenance operations must be possible, even preferred. Indeed, the service life of a module is dependent in particular on the fouling of the filtration elements. The main maintenance operation is the washing of the filtration elements which gradually become clogged during the successive filtrations. Another maintenance operation can for example be the replacement of defective filtration elements. Last but not least, these modules must be versatile enough to be deployed in areas lacking water supply and drinking water equipment. In particular, they must be able to be deployed in territories where the availability of water is limited to natural sources (rivers, lakes, ponds, groundwater, etc.), which can be polluted.

In order to better support local populations facing a humanitarian crisis and a state of natural disaster, rescue teams (eg army, non-governmental organizations, etc.) are always looking for equipment that is easily deployable, resistant to rudimentary transport conditions, robust and easy to use, with easy and possible maintenance by non-experts. This is particularly true of drinking water production and distribution facilities, which are a basic emergency need in a crisis situation.

3. Objectives of the invention

Thus, the present invention aims, in at least one embodiment, to provide a module for water filtration, and an installation containing it, allowing the production of drinking water in situations of emergencies, especially in the event of a humanitarian crisis and / or natural disaster.

The object of the present invention is, in at least one embodiment, to provide a module for water filtration, and an installation containing it, being robust, simple to use and easy to maintain, in particular by non-expert people.

The objective of the present invention is, in at least one embodiment, to provide a module for water filtration, and an installation containing it, which can be deployed in territories devoid of any drinking water treatment equipment. water. The present invention aims in particular, in at least one embodiment, to provide a filtration installation which can operate independently.

The present invention aims, in at least one embodiment, to provide a module for water filtration, and an installation containing it, which can be deployed in territories where the only available source of water is a natural source, for example a river, whose waters could be polluted.

The object of the present invention is, in at least one embodiment, to provide a module for water filtration, and an installation containing it, being compact enough to be able to be transported by any usual means, whatever either by air, sea or road, and in particular respecting the standard standards of air cargo.

The object of the present invention is, in at least one embodiment, to provide a module for filtering water which can be transported in an already assembled manner.

4. Statement of the invention

The present invention is according to the set of claims.

In a first aspect, the present invention relates to a module for water filtration, in particular for water microfiltration or rultrafiltration of water, comprising an enclosure closed by a cover and at least one hollow fiber filtration element.

The enclosure includes a point of injection of water to be filtered, a point of recovery of filtered water and optionally a point of emptying.

Each filter element has an upper end where the hollow fibers are open, the water being able to flow through said upper end only from inside the hollow fibers, and a lower end where the hollow fibers are closed.

The enclosure includes a high positioning plate and a low positioning plate arranged horizontally. The upper plate includes at least one through hole. The lower plate comprises at least one hole, through or blind, in alignment with the corresponding hole in the upper plate.

The water injection point is located between the upper and lower plates. The drain point is, if necessary, also arranged between the upper and lower plates. The water recovery point is located above the top plate.

The upper end of each filtration element is surrounded laterally by a high sheath comprising a flange.

The filter element is fitted at its upper and lower ends in the hole in the upper plate and the hole in the lower plate respectively, the collar of the upper sleeve forming a stop with a lower surface of the upper plate.

The expressions such as for example “top”, “bottom”, “upper”, “lower”, “above”, “below” are used to describe a module in its usual layout, that is to say say in a vertical "standing" position in order to allow a conventional upward flow of the water to be filtered from the bottom to the top. Indeed, according to this convention, the water to be filtered is injected at the injection point and fills, at least in part, the volume of the enclosure between the high plate and the low plate. Water passes through the walls of the hollow fibers while particles larger than the cut-off size of the hollow fibers are blocked by the walls of the hollow fibers. The filtered water inside the hollow fibers comes out from the top end of each filter element and is then collected at the enclosure recovery point located above the top plate. Alternatively, the terms "downstream" and "upstream" could be used.

The terminology below is used for clarity. This does not exclude the installation of the filtration modules in unusual positions. Indeed, in some cases, the filtration modules could be installed in an unusual manner, due to constraints specific to the territories concerned. Thus, such modules could be in an “inverted” vertical position in order to allow a gravitational flow of the water to be filtered from the top to the bottom. Alternatively, such modules could be in the horizontal "lying" position.

The module according to the invention thus allows a simple fixing of each filtration element by a double interlocking of the ends of each filtration element in the holes arranged for this purpose of the high and low plates. In other words, the filter elements are sandwiched between the two positioning plates. The upper plate rests more in part on the flange of each upper sheath, which stabilizes each filtration element and prevents them from moving in translation upwards. This has the advantage of ensuring good maintenance of each filtration element, which is necessary to guarantee their integrity throughout the life of the module. This allows in particular to guarantee that the module can be transported in any position and subjected to a certain number of shocks of small amplitude, without being affected. This also guarantees that the filtration elements are fixed appropriately with respect to the operating conditions of the module. Finally, this makes it possible to optimize the overall dimensions in height of the module: in fact, the fixing of each filtration element does not cause any additional dimensions in height than the very height of the filtration element, allowing a dimensioning of the module suitable for multiple modes of transport, including those of air cargo.

The enclosure comprises a casing, of advantageously cylindrical shape, terminated at its lower end by a base. The enclosure is closed in its upper part by a cover, advantageously in the form of a flattened ellipsoid. Preferably, the enclosure closed by its cover has a maximum height of 1600mm. This height limit is specifically adapted to transport by air cargo. Preferably, the footprint of the module is included in a rectangle with sides 1200 mm and 800 mm. This limited footprint is specifically adapted to transport by air cargo on pallets.

The enclosure can be constructed of different materials depending on the properties of the water to be filtered. The enclosure may in particular be made of plastic, stainless steel or coated, or even of composite material.

According to a preferred characteristic of the invention, the cover and the upper plate are removable. This has the advantage of allowing the replacement of a defective filter element. In fact, once the cover has been removed, the upper plate can be removed by simple disengagement with the filter element (s), the defective filtration element being able to be removed by simple disengagement with the lower plate. When the cover is removable, it is fixed to the enclosure with at least one removable fixing means, for example of the screw and nut type. The upper plate can in particular be made removable by placing the latter partly in abutment on a flange disposed in the upper part of the casing. Gripping means can also be arranged on the upper surface of the upper plate in order to make the latter more easily removable.

Alternatively, less preferably, the cover is not removable and is fixed to the enclosure permanently and permanently. This embodiment could be preferred when the module is deployed in a territory where the risks of degradation are high.

The water injection point notably allows the injection of water to be filtered during a filtration process. The drain point allows in particular to recover washing water loaded with solid particles during a washing process. 11 is advantageously arranged in the lower part between the upper plate and the lower plate. The drain point is optional. In fact, according to certain embodiments, a drain can be implemented at the water injection point. The recovery point makes it possible in particular to recover filtered water during a filtration process or to inject washing water during a washing process.

The filtration elements include hollow fibers, the upper part of which is surrounded by a high sheath comprising a collar. The top sleeve of each filtration element may include a smooth zone comprising at least one groove in which an O-ring is inserted. The insertion of an O-ring ensures a good seal at the socket between the upper end of a filter element and the corresponding hole in the upper plate. This has the advantage of ensuring that all the water collected at the recovery point is indeed water which has been filtered by the hollow fibers, and that the latter is not contaminated, even in a residual manner, by a contaminated water.

Each hole in the upper plate can be extended by an overhanging guide projecting downwards and forming a stop with the collar of the upper sleeve of each filtration element. This has the advantage of reducing the thickness of the upper plate while ensuring good maintenance of the upper end of each filter element.

According to a particular embodiment of the invention, the lower end of each filtration element is surrounded laterally by a low sleeve comprising a collar. The collar of the lower sleeve forms a stop with an upper surface of the lower plate. This embodiment hinders the downward movement in translation of each filtration element. According to this embodiment, each hole in the bottom plate can be extended by an overhanging guide projecting upwards and forming a stop with the collar of the bottom sheath.

The lower part of each filter element can also include at least one O-ring making it possible to ensure a good seal at the level of the socket between the lower end of a filter element and the corresponding hole in the lower plate.

Each hole in the bottom plate is preferably a through hole. Alternatively, each hole in the bottom plate could be blind, and therefore only form a notch in which the filter element would rest.

The lower end of each filter element may include perforations. Such perforations can be intended in particular for the passage of air. The use of such filtration elements is particularly recommended with low plates whose holes are through. If air is injected into the lower part of the enclosure, that is to say below the lower plate, this air will pass through the perforations of the filtration elements, causing the vibration of the hollow fibers. Such vibrations allow a mechanical washing action of the hollow fibers. Air can be injected at an air injection point located below the low plate and purged by means of at least one air vent disposed between the high plate and the low plate.

Preferably, the upper plate comprises several holes of the same diameter aligned one by one with corresponding holes in the lower plate. According to a particular embodiment, the upper and lower plates each include eight holes.

In a second aspect, the invention also relates to a water filtration process. This process includes a filtration step in a module according to the invention comprising:

- the continuous injection of water into said module at the water injection point and,

- the continuous recovery of filtered water in said module at the recovery point.

Due to the use of hollow fiber filtration elements, the filtration process is of the microfiltration or ultrafiltration type. Microfiltration is understood to mean filtration allowing particles larger than 10 to 0.1 µm in size to be blocked. The term “ultrafiltration” is understood to mean a filtration making it possible to block particles of size greater than a size of between 0.1 μm and 0.01 μm. According to a particular embodiment, the hollow fiber filtration elements of the module make it possible to block particles larger than 0.04 μm.

Water is preferably injected at a relative pressure between 0.1 and

1.5 bars, preferably at a relative pressure between 0.3 bar and 1.2 bar. The process can thus be implemented with conventional pumps and consumes little energy. According to a particular embodiment, the hollow fibers of each filtration element are hollow fibers which block particles larger than 0.04 µm. This embodiment has the advantage of being implemented at low pressure while guaranteeing good filtration rate and good filtration quality.

The method may include at least one clarifying filtration step before the filtration step in the module. By clarifying filtration is meant a filtration making it possible to retain particles of size greater than a size between 450 μm and 10 μm. The clarifying filtration stage makes it possible to remove the larger particles in order to limit clogging of the filtration module and therefore the frequency of washing of the filtration elements. According to a particular embodiment, said clarifying filtration step makes it possible to retain particles of size greater than 130 μm. This embodiment has the advantage of allowing efficient clarifying filtration while guaranteeing a low pressure drop.

The process may include a step of filtration on activated carbon after the step of filtration in the module. The activated carbon filtration stage makes it possible to trap certain coloring and / or olfactory substances not retained by the filtration elements. Indeed, although these substances do not present a real health hazard, it is preferable to remove them from the water in order to obtain water which is as colorless and odorless as possible which can be identified as "healthy water". The activated carbon filtration stage also possibly traps certain chemical pollutants.

In a third aspect, the invention also relates to a method for washing a module according to the invention. This process includes injecting a washing solution into the module, injecting air at the air injection point, the air vibrating the hollow fibers, and recovering the washing solution at level of the water injection point of the module and / or if necessary at the level of the drainage point. The injected air creates strongly turbulent flows between the hollow fibers in order to unhook the particles which accumulate on the external surface of the walls of the hollow fibers.

With a conventional air compressor, air can in particular be injected at a pressure between 0 and 8 bars. In particular, air can be injected at a pressure higher than 1 bar, a pressure higher than 2 bars, a pressure higher than 3 bars, a pressure higher than 4 bars, a pressure higher than 5 bars, a pressure higher than 6 bars, a pressure higher than 7 bar, or even a pressure equal to 8 bars.

In a fourth aspect, the invention relates to a mobile water filtration installation comprising:

- a module according to the invention;

- pumping means adapted to move water to be treated from a source to the injection point of the module;

- connection means between the source of water to be treated, said connection means and said module.

The mobile installation can also include additional filtration means placed before or after the module, in particular screening means, clarifying filtration, filtration on activated carbon, flow control means placed before or after the module, means for controlling the quality of the water entering or leaving the module, energy supply means and water storage means placed before or after the module.

The mobile installation can also include an air compressor making it possible to inject, if necessary, compressed air at the air injection point of the module.

This type of installation can be easily assembled and disassembled and moved as required. In addition, this type of installation can be implemented independently and does not require preexisting infrastructure.

5. List of figures

The invention, as well as the various advantages which it presents, will be more easily understood thanks to the description which will follow of a nonlimiting embodiment thereof, given with reference to the following Figures:

Figure IA shows a front view of a filtration module according to the invention. As already mentioned above, a convention of a vertical flow from the bottom to the top of the water has been adopted.

Figure IB shows a sectional view of the filtration module according to Figure IA, for which the cover has been removed. Of the filtration elements, only the central filtration element is shown for clarity.

Figure IC is an enlargement of Figure IB at the bottom plate.

Figure ID is an enlargement of Figure IB at the top plate.

Figures 2A and 2B show the upper end, respectively the lower end, of a filter element used in the module according to Figure IA.

Figures 3A and 3B show the high perspective positioning plate, respectively seen from the front, of the module according to Figure IA.

Figure 4 schematically represents an installation comprising the module according to Figure IA.

6. Detailed description of an embodiment

6.1 - Filtration module

With reference to Figures IA, IB, IC and ID, the filtration module 1 comprises an enclosure 10 and eight filtration elements 50 with hollow fibers 55.

The enclosure 10 comprises a casing 11, of mainly cylindrical shape. The casing 11 is terminated at its lower end by a base 12 and at its upper end by a flange 13.

The enclosure 10 is closed in its upper part by a removable cover 14, provided with a flange 15. The cover 14 has the shape of a flattened ellipsoid.

The enclosure 10 also comprises a low positioning plate 20 and a high positioning plate 30, which are substantially horizontal.

The bottom plate 20 has a diameter substantially equal to the inside diameter of the casing 11. It is fixed to the bottom of the enclosure 10 without however touching the base 12. It can in particular be welded or glued to the side walls of the casing 11.

The upper plate 30 has a diameter greater than the inside diameter of the casing 11. It rests on the flange 13 of the casing 11.

A set of bolts 18 is arranged uniformly in a circular geometry, which bolts passing through the flange 15 of the cover 14, the high plate 30 and the flange 13 of the casing 11. The bolts 18 thus make it possible to tighten the flange 15 of the cover 14 , the upper plate 30 and the flange 13 of the casing 11. Flat circular seals (not shown) can be inserted between the flange 15 of the cover 14 and the high plate 30, and / or between the flange 13 of the casing 11 and the plate high 30. This makes it possible to guarantee good sealing between the inside and the outside of the enclosure 10.

As will be described in more detail below, the filtration elements 50 are fitted at their upper 51 and lower 52 ends into holes 31 in the high plate 30, respectively in the low plate 20.

The enclosure 10 has a water injection point 41, a drain point 47 and an injection point for chemical washing 48, all three disposed between the bottom plate 20 and the top plate 30, at the bottom . As will be described in more detail in the sections dedicated to the filtration process and to the washing processes, the point of injection of water 41 makes it possible to inject water to be filtered during a filtration process and the point of drain 47 makes it possible to recover washing water loaded with solid particles during the washing processes. Note that the drain point 47 is optional since the washing water loaded with solid particles could possibly be recovered at the water injection point 41. As will also be described in more detail in the section dedicated to washing processes, the injection point for chemical washing 48 makes it possible to inject chlorinated water in a washing process. Note that the injection point for chemical washing 48 is optional since chlorinated water could possibly be injected at the point of injection of water 41.

The enclosure 10 also has a recovery point 42, disposed on the cover

14. The recovery point 42 makes it possible to recover filtered water or to inject washing water. Note that a washing water injection point could also be arranged on the cover 14 separately from the recovery point 42.

In addition, the enclosure 10 has an air injection point 43, disposed between the base 12 and the bottom plate 20. The air injection point 43 makes it possible to inject air into the enclosure 10 , useful especially during a washing process. Finally the enclosure 10 has an air vent 45 at the top of the volume located between the low 20 and high 30 plates for purging the air introduced into the enclosure 10. The enclosure 10 also has an air vent 46 at the top of the cover 14 making it possible to purge the air which is possibly in the enclosure 10 above the high plate 30.11 it should be noted however that the hollow fibers 55 are normally impermeable to air.

The enclosure 10 can be constructed of different materials depending on the properties of the water to be filtered. The enclosure may in particular be made of plastic, stainless steel or coated, or even of composite material.

The dimensioning of the filtration module 1 is specifically adapted to transport by air freight on pallets. Indeed, it has a footprint adapted to have a maximum footprint of 1200mm x 800mm ("pallet size") and a maximum height of 1600mm. More precisely, the height of the module 1 (height of the casing 11 + height of the cover 14) is exactly 1600mm. The casing 11 has an internal diameter of 502mm. The internal volume of the part of the casing 11 between the upper plate 30 and the lower plate 20 has a volume of 227 liters when empty (without filter element 50) and of 214L once the filter elements 50 are in place.

With reference to FIGS. 2A and 2B, the filtration elements 50 are of substantially cylindrical shape and comprise a set of hollow fibers 55 held together by a grid (not shown) surrounding them. At the upper end 51 of a filtration element 50, the hollow fibers 55 see their end emerge from a rigid coating block 510. The rigid coating block 510 is made of a resin impermeable to water. 'water. At the lower end 52 of a filter element 50, the end of the hollow fibers 55 is embedded in a rigid coating block 520. The rigid coating block 520 is also waterproof. Thus, the hollow fibers 55 are open at their top end and closed at their bottom end. This makes it possible to recover filtered water at the top end 51 of the filter element 50. In addition, the rigid coating block 520 has perforations 58 allowing the air to pass on either side. of the low plate 20 between the hollow fibers 55.

A high sheath 60 surrounds the high end 51. The high sheath 60 comprises from bottom to top, a flange 62 and a smooth zone 61 comprising two grooves into which two O-rings 63 are introduced. The O-rings 63 make it possible to provide a good sealing between the volume inside the enclosure 10 between the low plates 20 and high 30 and, the volume inside the enclosure 10 located above the high plate 30.

A lower sleeve 70 surrounds the lower end 52. The lower sleeve 70 comprises a flange 71. An O-ring 73 is arranged around the rigid coating block 520 of the lower end 52.

The filtration elements 50 have a height of 1195 mm and a diameter of 130 mm at their upper end 51.

With reference to FIGS. 3A and 3B, the high plate 30 comprises eight through holes 31 of the same diameter. The diameter of a hole 31 is adapted to allow the nesting of the upper end 51 of a filtration element 50. An overhanging guide 33 of the same diameter as a hole 31 extends each hole 31, projecting downwards . The lower end of the protruding guides 33 forms a stop against the flange 62 of the upper sleeve 60 of the filter elements 50. The protruding guides 33 ensure good maintenance of the upper end 51 of the filter elements 50 while reducing the thickness of the high plate 30. The low plate 20 has the same elements as the high plate 30, in particular eight through holes in alignment with the through holes 31 of the high plate. The flange 71 of the lower sleeve 70 of the filter elements 50 form a stop against an upper surface of the lower plate 20, this upper surface possibly also being able to be formed by protruding guides projecting upwards.

The upper plate 30 also comprises gripping elements 32 arranged on its upper surface. The gripping elements 32 make it possible to remove the upper plate 30, in particular when the filtering elements 50 have to be changed. The high plates 30 and low 20 have a thickness of 150 mm. The holes 31 which are arranged therein have a diameter equal to 132 mm. The high plate 30 also has a diameter of 590 mm, greater than the internal diameter of the casing 11.

6.2 - Filtration installation

With reference to FIG. 4, a mobile installation 100 comprising a filtration module 1 according to the invention can be deployed near a source of water to be treated 105. The source of water to be treated 105 is non-potable water , especially because of the microparticles and / or microorganisms it contains. The installation 100 makes it possible to obtain drinking water 106 at the outlet of the installation.

The mobile installation 100 comprises, upstream of the module 1, one or more clarifying filtration units 2; 5. The installation 100 may in particular comprise a screening unit 2 arranged at the level of the withdrawal of the water to be treated 105. The screening means 2 may for example comprise a strainer making it possible to retain particles of size greater than 500 qm. The installation can also include a pre-filtration unit 5. The pre-filtration means 5 can for example be a filter making it possible to retain particles of size greater than 130 μm. The screening unit 2 and the pre-filtration unit 5 make it possible to limit excessively rapid fouling of the module

1. The installation 100 also includes a pump 3 making it possible to transport the water to be treated from its source 105 to the module 1 and elements making it possible to control the injection of water into the module 1, including in particular one or more valves 4, one or more pressure reducers 6 and one or more flowmeters 7. The flowmeters 7 can be meters provided with a transmitting head, making it possible for example to control via a control module (not shown) the addition of products chemicals such as chlorine as a function of the flow rate or even simple rotameters to control the flow rate with the naked eye.

The installation 100 comprises in parallel, upstream of the module 1, an air compressor 9 making it possible to introduce compressed air into the module 1, useful during the washing of the latter.

The installation 100 comprises, downstream of the module 1, an activated carbon filtration unit 8. The activated carbon filtration unit 8 makes it possible to retain any chemical pollution and / or certain coloring and / or olfactory substances not retained by the module 1. A chlorine addition unit (not shown) can also be placed downstream of module 1 in order to limit any new contamination.

Connection means 9, such as pipes, allow the various elements of the installation 100 to be connected together. Power supply means (not shown), such as a generator, make it possible to supply power to the pump 3 or the air compressor 9 when these are not self-powered. Water storage means (not shown) can be arranged upstream of the module 1 for storing water to be treated and / or downstream for storing drinking water 106.

Thus all of the elements constituting the installation 100 can be transported by air cargo. The installation 100 is easily assembled, dismountable and movable. It is also completely autonomous and does not require any preexisting infrastructure.

6.3 - Filtration process of a module

Water to be filtered is injected at the water injection point 41 of a module 1. The water to be filtered fills the volume of the enclosure 10 comprised between the low plate 20 and the high plate 30. The fibers hollow 55 of the filter elements 50 allow the water molecules to pass through and retain particles larger than a cut-off value for the hollow fibers. The water thus filtered inside the hollow fibers 55 emerges from the upper end 51 of the filtration elements 50 and pours into the volume of the enclosure 10 situated above the upper plate 30. The filtered water is retrieved at recovery point 42.

For hollow fibers retaining particles larger than 0.04 µm, a relative injection pressure ranging from 0.3 bar to 1.2 bar can be used. In particular, at a relative injection pressure of between 0.3 and 1.2 bars, a module filtration rate of 7.5 m ³ / h is obtained with most of the raw water 105.

6.4 - Module washing procedures

Generally in the washing methods of module 1, a washing solution is introduced into module 1. In addition, air is introduced at the air injection point 43. Due to the perforations 58 in the rigid coating block 520 of the lower end 52 of the filtration elements 50, the air diffuses between the hollow fibers 55 thus creating highly turbulent flows making it possible to unhook the particles fixed on the external surface of the hollow fibers 55. washing solution loaded with particles is recovered at the drain point 47 of module 1.

More specifically, there are two types of washing processes.

The first type of washing process is a simple process carried out very regularly, for example daily. This process includes filling the interior volume of the casing 11 between the upper plate 30 and the lower plate 20 by injecting unfiltered water at the water injection point 41. Then air is injected into the level of the air injection point 43 for approximately 2 minutes. Finally, filtered water is injected at recovery point 42 for 3 to 5 minutes at a flow rate equal to approximately 1.5 times the filtration flow rate. The filtered water injected at the recovery point penetrates inside the hollow fibers 55 then crosses their wall thus promoting the detachment of the particles fixed on the external surface of the hollow fibers 55. This process is sometimes called "backwashing", this process washing being done from a flow of water in the opposite direction to the filtration process. A solution loaded with particles is finally recovered at the drain point 47 of module 1.

The second type of washing process is a chemical process carried out more rarely, in particular in the event of non-recovery of the performance of module 1 despite the simple washing implemented according to the first type of process. This method comprises filling the interior volume of the casing 11 between the upper plate 30 and the lower plate 20 by injecting filtered chlorinated water at the point of the injection point for chemical washing 48. Then air is injected at the air injection point 43 for approximately 2 min every 30 minutes over a total period of 2 hours. Finally, the module 1 is emptied at the drain point 47.

6.5 - Maintenance of a module

The maintenance of module 1 does not require any particular expertise.

Periodically, for example daily, the module 1 must be washed according to the first type process described in the previous section. Depending on the characteristics of the water to be treated, washing according to the second type process is also more or less frequent, for example weekly, monthly or quarterly.

In addition, after a long use of a module 1, certain filtration elements must be replaced following the breakage of hollow fibers 55. It then suffices to remove the cover 14 and the high plate 30. The filtration modules 50 deemed to be defective can then be replaced.

Claims (13)

1. Module (1) for water filtration, in particular for water microfiltration or ultrafiltration of water, comprising an enclosure (10) closed by a cover (14) and at least one filtration element (50 ) hollow fiber (55), said enclosure (10) comprising a water injection point (41) to be filtered, a recovery point (42) of filtered water and optionally a drain point (47); said at least one filter element (50) having a high end (51) where the hollow fibers (55) are open, the water being able to flow through said high end (55) only through the interior of the hollow fibers, and a bottom end (52) where the hollow fibers are closed; said module (1) being characterized in that: said enclosure (10) comprises an upper positioning plate (30) and a lower positioning plate (20) arranged horizontally, said upper plate (30) comprising at least one opening hole (31), and said lower plate (20) comprising at least one hole, opening or blind, in alignment with the corresponding hole (31) of said high plate (30); said water injection point (41) is disposed between said upper (30) and lower (20) plates; said drain point (47) is, if necessary, disposed between said upper (30) and lower (20) plates; said water recovery point (42) is arranged above said top plate (30); the upper end (51) of said at least one filter element (50) is surrounded laterally by a high sheath (60) comprising a flange (62); and, said at least one filter element (50) fits at its top (51) and bottom (52) ends in said at least one hole (31) of the top plate (30) and said at least one hole respectively of the lower plate (20), said flange (62) of said upper sleeve (60) forming a stop with a lower surface (33) of said upper plate (30). 2. Module (1) for water filtration according to claim 1, characterized in that the lower end (52) of said at least one filtration element (50) is surrounded laterally by a low sheath (70) comprising a collar (71), said collar (71) of said lower sleeve (70) forming a stop with an upper surface of said lower plate (20). 3. Module (1) according to any one of the preceding claims, characterized in that said cover (14) and said high plate (30) are removable. 4. Module (1) according to any one of the preceding claims, characterized in that said at least one hole in said bottom plate (20) is a through hole, said enclosure (10) comprises an air injection point ( 43) disposed below said bottom plate (20) and at least one air vent valve (45) disposed between said top plate (30) and said bottom plate (20), and said bottom end (52) of said at least one filtration element (50) comprises perforations (58) intended to allow air to pass on either side of said low plate (20) between the hollow fibers (55) of said at least one filtration element (50) . 5. Module according to any one of the preceding claims, characterized in that said top sheath (60) of said at least one filter element (50) comprises a smooth zone (61) comprising at least one groove in which a seal is inserted O-ring (63). 6. Module (1) according to any one of the preceding claims, characterized in that said at least one hole (31) of said high plate (30) is extended by an overhanging guide (33) projecting downward and forming abutment with the collar (62) of said upper sheath (60) of said at least one filtration element (50). 7. A method of filtering water comprising a step of filtering in a module according to any one of claims 1 to 6, said step of filtering in said module comprising: - the continuous injection of water into said module at the water injection point and, - the continuous recovery of filtered water in said module at the recovery point. 8. A filtration method according to claim 7, characterized in that the hollow fibers of said at least one filtration module make it possible to block particles of size greater than a size between 0.1 μm and 0.01 μm; preferably the hollow fibers of said at least one filtration module make it possible to block particles of size greater than 0.04 μm. 9. A filtration method according to one of claims 7 or 8, characterized in that said water is injected at the injection point at a relative pressure between 0.1 and 1.5 bars, preferably at a relative pressure between 0.3 bar and 1.2 bar. 10. A filtration method according to any one of claims 7 to 9, characterized in that it comprises at least one clarifying filtration step before the filtration step in said module. 11. A filtration method according to any one of claims 7 to 10, characterized in that it comprises a step of filtration on activated carbon after the step of filtration in said module. 12. A method of washing a module according to any one of claims 4 to 6, said method comprising an injection of a washing solution, an injection of air at the air injection point, the injected air vibrating the hollow fibers and, recovering the washing solution at the water injection point and / or, if necessary, the emptying point of said module. 13. Mobile installation (100) of water filtration comprising: - a module (1) according to any one of claims 1 to 6; - pumping means (3) adapted to move water to be treated from a source (105) to the point of injection of said module (1); - connection means (9) between the source of water to be treated, said connection means and said module.