Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/02—Hollow fibre modules
  • B01D63/04—Hollow fibre modules comprising multiple hollow fibre assemblies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/02—Hollow fibre modules
  • B01D63/04—Hollow fibre modules comprising multiple hollow fibre assemblies
  • B01D63/043—Hollow fibre modules comprising multiple hollow fibre assemblies with separate tube sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
  • B01D61/14—Ultrafiltration; Microfiltration
  • B01D61/18—Apparatus therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D63/00—Apparatus in general for separation processes using semi-permeable membranes
  • B01D63/02—Hollow fibre modules
  • B01D63/033—Specific distribution of fibres within one potting or tube-sheet
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/02—Specific tightening or locking mechanisms
  • B01D2313/025—Specific membrane holders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/06—External membrane module supporting or fixing means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/10—Specific supply elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/12—Specific discharge elements
  • B01D2313/125—Discharge manifolds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2313/00—Details relating to membrane modules or apparatus
  • B01D2313/21—Specific headers, end caps
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2315/00—Details relating to the membrane module operation
  • B01D2315/06—Submerged-type; Immersion type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2315/00—Details relating to the membrane module operation
  • B01D2315/20—Operation control schemes defined by a periodically repeated sequence comprising filtration cycles combined with cleaning or gas supply, e.g. aeration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2321/00—Details relating to membrane cleaning, regeneration, sterilization or to the prevention of fouling
  • B01D2321/18—Use of gases
  • B01D2321/185—Aeration
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D65/00—Accessories or auxiliary operations, in general, for separation processes or apparatus using semi-permeable membranes
  • B01D65/08—Prevention of membrane fouling or of concentration polarisation

Definitions

• the present invention is in the field of water treatment, more particularly the filtration of large volumes of water by membranes of the hollow fiber type, especially for community water supply.
• the present invention relates to a water filtration module having a plurality of hollow fiber water filtration elements configured to provide water filtration from the outside to the inside of the hollow fibers.
• the invention also relates to a method of manufacturing a water filtration module according to the invention. It further relates to a water treatment plant, comprising such a water filtration module, and a water filtration element configured to removably assemble in such a water filtration module.
• the present invention more particularly relates to ultrafiltration modules of the type arranged vertically in use, using hollow fibers fed with water under pressure, and configured so that the desired filtration is achieved by crossing the water of the water. exterior to the interior of the fiber, through the porous wall of the latter, which constitutes the filtration membrane.
• these modules of generally cylindrical shape, comprise substantially cylindrical beams of several hundred such hollow fibers.
• these modules are supplied with raw water by their upper end.
• Hollow fibers are open at their upper end and closed at their lower end, so that the purified water, after passing through the wall of the hollow fibers, out of the upper part of the filtration module, where it is collected.
• the treatment sludge is evacuated by a lower drain.
• water treatment facilities based on such filtration modules can effectively filter large volumes of water, while occupying a small floor area and being simple and quick to implement, these facilities require however for their operation an amount of energy that may be too important for some users.
• the present invention aims to remedy the drawbacks of the water filtration modules proposed by the prior art, in particular to the disadvantages described above, by proposing a water filtration module of the hollow fiber type, which makes it possible to ensure efficient filtration of large volumes of water while being less energy-consuming for its operation than hollow fiber filtration modules proposed by the prior art.
• the present inventors it is advantageously proposed by the present inventors to reduce the energy demand of the water filtration modules by reducing the water pressure necessary for the operation of these filtration modules.
• the water pressure necessary for a good operation is at least equal to 0 , 5 bars.
• a water filtration module of the type comprising a plurality of hollow fibers configured to allow filtration of the water from outside to inside the fibers, which is able to function effectively at a water pressure as low as 0.3 bar.
• a water filtration module of the hollow fiber type comprising:
• each of the water filtration elements being such that:
• the upper end portion of the fibers is included in a first rigid coating block, this first rigid coating block not clogging the fibers in their upper end portion,
• filter elements are not bonded to each other, and are not in particular potted in one or more block (s) of common coating (s).
• each of the water filtration elements is such that: the lower end portion of the fibers is included in a second rigid coating block, this second rigid coating block not sealing the fibers in their lower end portion,
• a longitudinal hollow tube is disposed in the bundle of fibers, substantially in the center of the latter, so as to extend at least over the entire height of the bundle, preferably along a longitudinal axis substantially coaxial with the longitudinal axis of the fiber bundle, and to open on both sides of the first coating block and the second coating block
• the filter element further comprises a cap sealingly attached to the fluids around the second coating unit.
• This cap is arranged so as to provide, between it and the second coating unit, a chamber, said lower chamber, which is in hydraulic communication with the hollow fibers and with the central tube, at the lower part of the fibers.
• central tubes of each of the water filtration elements are in hydraulic communication with the upper permeate collection chamber at the top of the fibers.
• the water filtration module thus comprises an upper permeate collecting chamber which is collective, that is to say common to all the water filtration elements of the module, and a plurality of lower chambers. which are individual, each being associated with one of the water filtration elements of the module.
• such a water filtration module is advantageously able to operate with very low input water pressures, while achieving a filtration that is almost as powerful, or even as efficient, as the filtration modules of the system.
• hollow fiber bundle type proposed by the prior art.
• the insertion of a tube into the fiber bundle, substantially in the center of the latter impacts only very little, if any, filtration performance of the filter element, for the same diameter of the hollow fiber bundle, when the external dimensions of the central tube remain small compared to this diameter.
• the outer diameter of the central tube is chosen so as not to reduce by more than 5 to 6% the filtration area of the filter element, compared to a configuration in which the space occupied by the central tube would be occupied by hollow fibers, normally spaced apart from each other.
• the filtration performance is very little affected when the central tube has an external diameter less than or equal to 1, 2 cm.
• This outer diameter is for example between 1 and 2.5 cm.
• the complexity of the filtration elements of the water filtration module according to the invention is advantageously compensated by the ease of assembly / disassembly of these filtration elements in the filtration module of water.
• the reduction in the filtering area induced by the presence of a central tube in each bundle of fibers may in particular be compensated by an increase in the height of the hollow fibers used, which may advantageously be carried out with a low additional cost, and without impacting the footprint of the installation incorporating the filter elements.
• the filtration module when raw water is injected into the filtration module in which it is disposed, this water, arriving from the upper part or the lower part of the module to the outside of the hollow fibers, passes through the wall of the fibers. Part of the filtration permeate rises through the upper end of the fibers into the upper permeate collection chamber into which the fibers open at the upper end of the module. Another portion of the filtration permeate descends into the fibers to the lower end of the fibers and then into each lower chamber formed between the lower portion of the fibers and each associated cap. From there, the permeate goes up in the central tube, until reaching the upper part of the filtration module, and in particular the upper permeate collection chamber.
• the water filtration module according to the invention may furthermore meet one or more of the characteristics described below, implemented individually or in each of their technically operating combinations.
• the cap in at least one of the water filtration elements, preferably in all of the water filtration elements, is irreversibly fixed around the second coating block. . It is for example fixed by gluing or welding, in particular to a bottom sleeve enclosing the hollow fibers in their lower end portion. Such a low sheath can then be conventional in itself for water filtration elements of this type.
• Such a configuration offers the advantage of a simplified manufacturing process of the constituent parts of the filter element of the water filtration module according to the invention.
• the cap in at least one of the water filtration elements, preferably in all of the water filtration elements, is reversibly fixed around the second coating unit. It is for example fixed by screwing, in particular around a bottom sleeve enclosing the fibers in their lower end portion. In such a configuration, the cap and the bottom sheath are provided with cooperating fastening means.
• the cap may for example comprise a threaded zone adapted to be screwed into a complementary threaded zone formed on the outer surface of the bottom sheath.
• Such a configuration offers the advantage of allowing disassembly of the cap, in particular to allow access to the lower end of the hollow fibers.
• the fiber bundle in at least one of the water filtration elements, preferably in the entirety of the water filtration elements, is kept in shape by a grid, that is to say an envelope with openwork wall, which surrounds it.
• This grid is preferably flexible or semi-rigid.
• this grid has a small thickness, in particular a thickness between 0.5 and 3 mm. It also preferably has a high perforation surface area, in particular between 20 and 80%.
• Such characteristics which are advantageously made possible by the stiffening of the fiber bundle induced by the presence in the latter of the central tube, which is preferably rigid, this tube being otherwise potted in the coating blocks of the end portions fibers, advantageously reduce the manufacturing cost of the water filtration elements forming part of the water filtration module according to the invention, compared with the water filtration elements of the prior art, which comprise holding grids in the form of fiber bundles that are thicker and less openwork.
• These features also make it possible to integrate more filter fibers in a filter element of the same external diameter, and they facilitate the passage of the water to be filtered to the fibers, and the washing water in the opposite direction, improving consequently, moreover, the filtration performance of the water filtration module according to the invention.
• At least one of the water filtration elements comprises a top sleeve enclosing the fiber bundle at their part of the water. upper end and a lower sleeve enclosing the fiber bundle at their lower end portion.
• a grid in particular a flexible grid, the latter preferably attaches respectively to this top sleeve and to this bottom sleeve.
• the upper sheath may be conventional in itself, and in particular include means for mounting the filter element in the filtration module.
• At least one water filtration element comprises an air injector extending around the central tube at the level of the lower end portion of the fibers and opening into the beam of fibers beyond the second rigid coating block, in the middle of the fiber bundle.
• an air injector extending around the central tube at the level of the lower end portion of the fibers and opening into the beam of fibers beyond the second rigid coating block, in the middle of the fiber bundle.
• the water filtration elements are removably assembled in the housing, by cooperating assembly means carried respectively by the module and by each of the elements.
• These cooperating assembly means may be conventional in themselves. They are preferably arranged in the upper part of the filtration module.
• the water filtration module comprises an upper plate disposed in the housing.
• the water attachment elements are preferably suspended from this upper plate, so as to extend substantially along the longitudinal axis of the housing.
• the water filtration module according to the invention then comprises cooperating assembly means carried respectively by the upper plate and by the filter elements, for the removable assembly of the filter elements to the upper plate.
• the filtration module according to the invention can be supplied with water to be filtered by the upper end or the lower end of the module.
• a strainer coaxial with the longitudinal axis of the casing, whose length is substantially equal to that of the casing, for the distribution of water to be filtered in the casing.
• the strainer is preferably disposed substantially in the center of the casing, the water filtration elements being arranged around this strainer. in the housing, preferably arranged at regular intervals on several concentric circles around this strainer.
• the filtration module according to the invention may also be devoid of strainer, the water to be filtered must then be brought into a pre-filtered form.
• the housing may also contain, in a conventional manner in itself, a lower chamber for collecting filter sludge, that is to say solid or semi-solid particles contained in the effluent to be filtered, which do not not through the hollow fiber wall.
• the filtration module according to the invention may further comprise, preferably in the housing, a base comprising an air distribution circuit from a aeration nozzle that then comprises the filtration module to said air injector.
• the present invention relates to a method of manufacturing a water filtration module according to the present invention, corresponding to one or more of the characteristics above or below. This process comprises steps of:
• the upper permeate collecting chamber is in hydraulic communication with the hollow fibers and the central tubes of all the filtration elements of the water, at the level of the upper part of the fibers.
• the fluid-tight fixing of the cap around the second coating block can be irreversibly effected, for example by gluing or welding, or reversibly, for example by screwing, this fixing preferably being carried out at a bottom sheath enclosing the bundle of fibers at the lower end portion of the fibers.
• the coating steps of the upper end portion and the lower end portion of the fibers may be performed by any conventional technique in itself. They can for example use a two-component resin, in which the end portions of the fibers are inserted before the resin is hardened so as to form a rigid block encasing the end portions of the fibers, without, however, closing off the latter. at these end portions.
• At least one water filtration element according to the invention For its removable assembly in the filtration module, at least one water filtration element according to the invention, preferably all of the water filtration elements according to the invention, are suspended in the housing, in particular to the upper plate, around the strainer of water distribution to be filtered.
• Another aspect of the invention relates to a water treatment plant, which comprises:
• a water inlet pipe to be filtered in the casing preferably connected to an upper end of the strainer
• a filtration permeate collection pipe connected to the upper permeate collection chamber.
• the installation also comprises a filtration sludge drain connected to the lower filter sludge collection chamber.
• it may further comprise a compressed air distribution system connected to the ventilation nozzle of the water filtration module, when the water filtration module includes such a vent nozzle.
• the water treatment installation according to the invention may further comprise a valve control automaton of the various pipes, drains and circuits, this automaton being attached to the water filtration module in a conventional manner in itself, and any other conventional organ or device in itself.
• a water filtration element configured to removably assemble in a water filtration module according to the invention.
• This water filtration element can meet one or more of the characteristics described above with reference to the water filtration module according to the invention.
• it comprises a plurality of longitudinal hollow fibers configured to allow filtration of the water from the outside towards the inside of the fibers, these fibers forming a bundle of fibers extending along a longitudinal axis, and having a part end upper and an opposite lower end portion.
• the upper end portion of the fibers is included in a first rigid coating block which does not seal the fibers in their upper end portion, and the lower end portion of the fibers is included in a second rigid coating block does not clog the fibers in their lower end portion.
• a longitudinal hollow tube is disposed in the bundle of fibers, in the center of this bundle, so as to extend at least over the entire height of the bundle and to open on either side of the first block of the bundle. coating and the second coating block.
• the filter element further comprises a cap fluid-tightly fixed around the second coating unit, this cap being arranged so as to provide, between it and the second coating unit, a lower chamber in hydraulic communication with the hollow fibers and with the central tube, at the lower end portion of the fibers.
• the fiber bundle is held in shape by a grid, particularly flexible, which surrounds it.
• Figure 1 shows a water filter element according to a particular embodiment of the invention, for section along a longitudinal plane;
• Figure 2 shows a magnification of the upper end portion of the water filter element of Figure 1;
• Figure 3 shows a magnification of the lower end portion of the water filter element of Figure 1;
• FIG. 4 shows a magnification of a section view according to a longitudinal plane of the lower end portion of a water filter element according to a different embodiment of the invention
• FIG. 5 shows a magnification of a sectional view along a longitudinal plane of the lower end portion of a water filter element according to an embodiment still different from the invention
• FIG. 6 shows a sectional view along a longitudinal plane of a water filtration module according to a particular embodiment of the invention
• FIG. 7 shows a magnification of the upper part of the water filtration module of Figure 6;
• FIG. 8 shows a magnification of the lower part of the water filtration module of FIG. 6.
• a water filtration module according to the invention comprises a plurality of water filtration elements, which are preferably all identically constituted.
• a water filtration element 10 according to the invention (hereinafter referred to as "element") is shown in FIG.
• This element 10 has a longitudinal overall shape, substantially cylindrical in this embodiment. It comprises a beam 101 of longitudinal hollow fibers 102, this beam also being of substantially cylindrical shape.
• hollow filter fibers 102 each have a diameter of a few tenths of a millimeter for a length of about 1.5 m. Their dimensional and material characteristics are known to those skilled in the art and are beyond the scope of the present invention. They are therefore not described further here.
• the bundle 101 has several thousand (typically about 4000) hollow fibers 102, the porous wall of which constitutes a filtration membrane. Such a beam 101 may for example have a diameter of 5 to 7 cm.
• the beam 101 is held in shape by a grid, for example a plastic 1 10, which surrounds it.
• This grid makes it possible to maintain the general shape of the beam, while allowing the fibers 102 to move naturally in the flow of water when they are in use.
• This grid has for example a thickness of between 0.5 and 3 mm, and a surface rate of perforations of between 20 and 80%. It is preferably advantageously flexible.
• the hollow fibers 102 open out of a first rigid resin coating block 103, said upper coating block, for example of the type component, known per se, for example with a height of about 5 cm. It is understood that, in this way, the water coming through the wall of the fibers 102, from the outside to the inside of the fibers, can circulate inside the fibers towards their upper end part, to get out at the upper end 1021 of the fibers.
• the hollow fibers 102 also open out of a second rigid resin coating block 104, called a lower coating block, for example of the type b). component, known per se, for example with a height of about 5 cm.
• the water circulating inside the fibers 102 can thus also exit at the lower end 1022 of the fibers.
• the fiber bundle 101 is clamped in a top sheath 105, arranged in particular around the upper encasing block 103. At its lower end portion, it is enclosed in a sheath bottom 106, disposed in particular around the lower coating block 104.
• a sheath bottom 106 disposed in particular around the lower coating block 104.
• the element 10 also comprises a hollow longitudinal tube 107, called the central tube, which is disposed substantially at the center of the fiber bundle 101, coaxially with the latter, and so as to extend at least over the entire length of this bundle 101
• the central tube 107 opens, at its upper end 1071, out of the upper encapsulation block 103, and at its lower end 1072, out of the lower encapsulation block 104.
• the central tube 107 is substantially cylindrical in the embodiment shown in the figures. It has for example a diameter of about 1.2 cm.
• the member 10 is covered by a cylindrical cap 108, which is sealingly attached to the fluids around the lower encapsulation block 104.
• the cap 108 is more particularly fixed on the bottom sleeve 106. It provides, between it and the lower encapsulation unit 104, a sealed lower chamber 109 which is in hydraulic communication with the fibers 102 at their lower end 1022, and with the central tube 107 at its lower end. 1072.
• This lower chamber 109 has for example a height of about 1 cm.
• the cap 108 has a bottom wall 1081, which closes the member 10 at its lower end, and a peripheral wall 1082, which surrounds the lower barrel 106 around its entire circumference.
• the upper sheath 105 encloses the hollow fibers 102 in the upper end portion of the element 10, at the level of the upper encasing block 103.
• the upper sheath 105 is flush with the same level as the upper one. upper end 1021 of the fibers 102, and extends about ten centimeters along the element 10.
• this upper sheath 105 although mainly cylindrical, comprises from top to bottom:
• a first threaded zone 1051 extending for example over 0.5 to 1 cm, a support ring 1052,
• a second threaded zone 1053 extending for example about 2 cm in height
• a smooth zone 1054 comprising grooves 1055 intended to insert two O-rings (not shown in the figure),
• this lower zone 1056 substantially frustoconical tightening downwards, intended to accommodate the upper edge of the grid 1 10 which encloses the hollow fibers 102 of the element 10.
• this lower zone 1056 comprises surface sculptures (Not shown), substantially complementary to the shape of the grid 1 10, and intended to allow the interlocking and locking of the grid 1 10 on the upper sheath 105.
• the bottom sheath 106 encloses the hollow fibers 102 in the lower end portion of the element 10, at the level of the lower encasing block 104.
• the bottom sheath 106 is flush with the same level as the 1022 lower end of the fibers, and extends for about ten centimeters along the element 10.
• the bottom sheath 106 is substantially cylindrical in shape, and in its upper part it has a frustoconical zone 1061 of substantially identical profile to that of the lower zone 1056 of the top sheath 105. and also intended to allow the interlocking and locking of the grid 1 10 on the bottom sheath 106.
• the cap 108 is fixed irreversibly, for example glued or welded, around the lower zone 1062 of the bottom sheath 106.
• this lower zone 1062 is smooth.
• the sealing of the attachment is provided by a seal disposed between the cap 108 and the lower zone 1062 of the bottom sleeve (not shown in the figures).
• a variant of the lower end portion of an element 10 according to the invention is shown in FIG. 4.
• the cap 108 is reversibly fixed to the bottom sheath 106, for example by screwing.
• the cap 108 and the bottom sheath 106 are provided with cooperating fixing means.
• the cap 108 may for example comprise, in its peripheral wall 1082, a threaded zone 1083 adapted to be screwed into a complementary threaded zone formed on the outer surface of the lower zone 1062 of the bottom sheath 106, as shown in FIG.
• O-rings 1084 for example two in number in the figure, are interposed between the peripheral wall 1082 of the cap 108 and the outer surface of the lower zone 1062 of the lower sleeve 106, so as to ensure the seal at this portion. lower.
• FIG. 5 A more sophisticated variant of the element 10 according to the invention is shown in FIG. 5.
• the element 10 comprises in its lower end part an air injector 11 which extends around the central tube 107, and whose function is to allow the injection of air between the hollow fibers 102 during cleaning phases.
• This air injector 11 1 is in the form of a hollow cylinder which crosses, in a fluid-tight manner, the bottom wall 1081 of the cap 108 and which fits around the lower part of the central tube 107, so as to emerge all around the latter, above the lower encapsulation block 104, in the middle of the fiber bundle 101, as indicated at 1 1 10 in FIG. 5.
• the air injector 1 1 1 is fixed in particular in the bottom wall 1081 of the cap 108 by screwing, a threaded zone of the air injector being for example adapted to be screwed into a complementary threaded zone formed in the bottom wall 1081 of the cap 108.
• O-rings 1 185 are interposed between the air injector 1 1 1 and the bottom wall 1081 of the cap 108, so as to seal the fastener between these components.
• the air injector 1 1 1 is pierced on its peripheral surface with orifices 1 1 1 1 allowing the exit of the air which circulates in the injector in the fiber bundle 102, around the central tube 107.
• the air injector 1 1 1 is further pierced by an internal channel 1 January 12, which, when the air injector is placed in its operative position around the central tube 107, is in hydraulic communication with firstly the central tube 107 and secondly the lower chamber 109.
• This channel 1 1 12 allows the circulation of the liquid contained in the lower chamber 109 to the inside of the central tube 107, as illustrated in 1 1 13 in Figure 5.
• the element 10 according to the invention can be manufactured as follows.
• the hollow fibers 102 are assembled in a bundle around the central tube 107, so that the latter extends at least over the entire height of the bundle 101.
• the upper end portion of the fibers 102 is embedded in a first coating block 103 which neither closes the fibers 102 nor the central tube 107 in the upper end portion of the fibers.
• the upper end 1021 of the fibers 102 and the upper end 1071 of the central tube 107 are flush with the surface of the coating block 103.
• the lower end portion of the fibers 102 is embedded in a second coating block 104 which does not seal either the fibers 102 or the central tube 107 in the lower end portion of the fibers.
• the lower end 1022 of the fibers 102 and the lower end 1072 of the central tube 107 are flush with the surface of the coating block 104.
• the upper sheath 105 and the bottom sheath 106 are put in place at the two opposite end portions of the bundle 101, and the grid 1 10 is assembled on these sheaths 105, 106.
• the cap 108 is fluid-tightly attached to the bottom barrel 106, so as to provide, between it and the second encapsulation block 104, the lower chamber 109 in hydraulic communication with the hollow fibers 102 and with the central tube 107. If necessary, the air injector 11 1 is screwed into the bottom wall 1081 of the cap 108, disposed around the central tube 107.
• FIG. 6 shows a filtration module 20 according to an exemplary embodiment of the invention.
• filtration elements which may be exclusively elements 10 according to the invention, or a mixture of these elements and conventional filtration elements January 1, are integrated in this filtration module 20.
• forty nine filtration elements may be arranged in three concentric circles, ten, sixteen and twenty-three elements arranged on these three concentric circles, leaving free a central water injection space to be treated. It is clear that these filtration elements are arranged so as to leave the minimum space unused between them, to minimize the volume of the module 20.
• the filtration module 20 described here by way of example comprises a casing 13, of predominantly cylindrical shape, terminated at its bottom end by a base 14, and at its upper part by a cover 15
• the base 14 and the cover 15 each have a substantially flat half-ellipsoid shape.
• the module 20 has a height of about 2 m for a diameter of 60 cm.
• this diameter can be increased arbitrarily to substantially higher values, depending on the number of filtration elements integrated in the module 20, which is directly related to the volume of water to be treated per hour of operation. In the case for example of a module 20 having about 200 filter elements, the diameter can reach 1, 2 m.
• the base 14 is secured to the casing 13 by joint molding during manufacture, welding, gluing or other technique adapted to the material constituting the casing 13. This can in particular be made of composite material in the case of treatment of seawater , or stainless steel or coated, or plastic in the case of freshwater treatment module.
• This base 14 comprises a central orifice 141, intended for the passage of a ventilation nozzle 142, and a lateral orifice 143 intended for the evacuation of the washing sludge collected in a lower collection chamber of the washing sludge 144 formed in the base 14.
• a filter sludge drain 1430 may be connected to this lower sludge collection chamber 144 at the side port 143.
• the filtration elements 10 are for example held in place within the housing 13 by:
• the base 17 can be connected to the ventilation nozzle 142, and include a circuit 171 for distributing air from this aeration nozzle 142 to the various air injectors 1 1 1 of the elements 10 integrated in the module 20.
• the base 17 also comprises a set of through holes intended to allow the free passage of water between the area above and the area below said base 17.
• the lid 15 is removable. It is fixed on the casing 13 by means of a conventional fastening device in itself, which will not be detailed here.
• the lid 15 has a central orifice 151 allowing the passage of a water supply pipe 1510 to be filtered.
• a seal seals between the lid 15 and the hose 1510.
• An upper permeate collection chamber 154 is formed in the lid 15.
• the lid 15 also has a lateral orifice 153 for recovering the filtration permeate.
• a filtration permeate collection pipe 1530 may be connected to the upper permeate collection chamber 154 at the side port 153.
• the hose 1530 for collecting the purified water is of diameter substantially equal to the diameter of the inlet pipe 1510 of water to be filtered. In the present example, this diameter is about 10 cm (for a flow of a few tens of m 3 / h).
• This strainer 18 is closed at its lower end 181, and connected to the inlet pipe 1510 of water to be filtered at its opposite upper end 182.
• the strainer 18 is of a type known per se. It is made of plastic or stainless steel, depending on the type of water to be treated (thickness a few tens to a few hundred miti).
• strainer 18 is intended to diffuse the water to be purified from top to bottom in the filtration module 20, towards the filtration elements 10.
• the filtration module 20 is devoid of a feed strainer.
• the water to be filtered is brought there for example by a pipe connected at the lower end of the filter module.
• the filtration module 20 is then equipped, for example at its upper end, with a pipe for purging the air contained in the filtration module.
• the elements 10 are fixed to the positioning plate 16 via the high sleeves 105, conventionally in itself, and so to be easily removable, for example to maintain the module by replacing some used elements.
• the casing 13, already provided with the base 17, is secured to the discharge line of the drain 1430 and the aeration nozzle 142. Then the central strainer 18 is installed and screwed to the base 17. The positioning plate 16 is then placed in abutment on a flange of the casing 13.
• the elements 10 are then inserted in the module 20.
• Each element 10 is fixed by screwing the upper sheath 105 to the positioning plate 16. Where appropriate, the air injectors 11 1 are connected to the air distribution circuit 171 of the base 17.
• the cover 15 is installed and fixed.
• the water inlet pipes 1510 to be treated and the filter permeate 1530 are then connected to the lid 15.
• FIGS. 7 and 8 show views of the upper and lower portions of the module 20, respectively.
• the water to be treated is injected by the inlet pipe 1510 into the strainer 18, as illustrated at 21 in FIG. 7. It is then distributed around the elements 10 under pressure, as illustrated in 22 in FIGS. 7 and 8, and passes through the membrane of the hollow fibers 102 of the elements 10. The water thus purified, partly, goes up inside the hollow fibers 102 and comes out at the top of these, in the upper filtration permeate collection chamber 154, as indicated at 23 in FIG.
• the other part of the purified water goes down inside the hollow fibers 102 to the lower chambers 109, where it joins, under the effect of the pressure, the associated central tubes 107 in which it rises, as indicated at 24 in Fig. 8. Reaching the top of the central tubes 107, the filtered water rejoins the upper filtration permeate collection chamber 154, as shown at 25 in Fig. 7.
• the purified water is then collected through the filtration permeate collection pipe 1530 as shown at 26 in FIG.
• These filtration operations can be performed at low incoming water pressure, while having a high filtration performance.
• the module 20 is regularly subjected to backwashing, the water being injected from the inside of the hollow fibers, so as to detach the filtration sludge which naturally stick to it during normal operation.
• the wash sludge then falls into the lower collection chamber 144 and is discharged through the drain 1430 as shown at 27 in FIG.
• Another method of washing the fibers 102 consists in injecting air under pressure by the air injectors 11 1, from the aeration nozzle 142, and in the middle of the bundle of hollow fibers of each element 10, as indicated. respectively at 28 and 29 in Figure 8.
• the flow of air and very turbulent water thus created shakes and causes the expansion of the fiber bundle 101, as well as the cleaning of the outer walls of the hollow fibers 102. This cleaning is all the more effective that the air was injected in the very middle of the fiber bundle 101.
• the air is then discharged at the top by the strainer 18, as shown in 30 in Figure 7.
• the scrubbing mode of the strainer 18 comprises a backwashing operation in which, initially, the sludge is directed towards the bottom of the module 20. This way, at the beginning of backwashing when the amount of particles is important, the flow does not cross the strainer 18 (which could clog it).
• the backwashing water becomes more and more clean, and the strainer 18 is then washed in the opposite direction, thus upwards, possibly adding an injection. of air in the center of the fiber bundle 101, which contributes to increase the effectiveness of the washing.
• the filtration performance of the module 20 is better maintained over time than when the filtration elements included in these modules are not in accordance with the present invention.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Water Supply & Treatment (AREA)
• Separation Using Semi-Permeable Membranes (AREA)

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Citations (3)

• 2018
  • 2018-01-15 FR FR1850282A patent/FR3076739B1/fr active Active
• 2019
  • 2019-01-14 AU AU2019207936A patent/AU2019207936A1/en not_active Abandoned
  • 2019-01-14 CA CA3088283A patent/CA3088283A1/fr active Pending
  • 2019-01-14 CN CN201980018917.5A patent/CN111818989B/zh active Active
  • 2019-01-14 US US16/961,251 patent/US20200384418A1/en not_active Abandoned
  • 2019-01-14 EP EP19703172.7A patent/EP3740303A1/de not_active Withdrawn
  • 2019-01-14 WO PCT/FR2019/050066 patent/WO2019138198A1/fr active Search and Examination

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