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
  • B01D63/16—Rotary, reciprocated or vibrated modules
• • 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
• • 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
  • B01D2321/20—By influencing the flow
  • B01D2321/2033—By influencing the flow dynamically
  • B01D2321/2058—By influencing the flow dynamically by vibration of the membrane, e.g. with an actuator

Definitions

• the field of the invention is that of the treatment, separation and purification of liquids. More specifically, the present invention relates to a membrane separation apparatus for the treatment of liquids by removing from said liquids suspended matter, emulsion and / or dissolved matter (minerals and organic). It also relates to a liquid separation system and method.
• the membrane separation device makes it possible to obtain two streams of liquid: a) a stream of permeate or filtrate devoid of all or part of the suspended, emulsion and / or dissolved materials (minerals and / or organic); this current representing the major part of the liquid to be treated; b) a stream of concentrate or retentate enriched in suspended matter, in emulsion and / or dissolved.
• the present invention also relates to the treatment of liquids containing chemicals, microbiological, pharmaceutical, food, which must be eliminated or concentrated effectively, entirely and / or selectively.
• an apparatus, a system and a method according to the present invention can be particularly advantageous thanks to the possibility of operating for a long time without clogging of the membranes or with attenuated clogging, with maintenance of a high level of permeability and requiring the minimum of pretreatment of said liquids to be treated.
• Liquid to be treated is an aqueous or organic liquid charged with organic or inorganic matter, whether in suspension and / or dissolved and / or in emulsion. This liquid is introduced into the membrane separation system for treatment.
• Liquid is the liquid being processed in the membrane separation apparatus. It is prepared from the liquid to be treated during the treatment phase which is called “concentration phase”.
• “Concentrate or retentate” is the portion of the liquid which has not passed through the membrane and which is enriched with materials retained by the membrane up to the desired concentration rate. As soon as the desired rate is reached the concentrate is purged while respecting the consistency of said concentration rate. From this moment begins the treatment phase which is called "separation ptrase”.
• Permeate or filtrate is the portion of the liquid which has passed through the membrane and which is devoid of some or all of the materials (colloidal, emulsified and7 or dissolved).
• Tr '100%
• V v is the volume of permeate
• c c is the volume of liquid in the concentration tank
• V c is the volume of liquid in the pipes.
• T is calculated by:
• Membrane or filtering medium is a filtration or separation medium which has as its object the more or less selective elimination of a portion or of all the materials - colloidal, emulsified and / or dissolved - which are found in the liquid.
• the membrane generally comprises at least two layers: - the first - the selective layer containing the finest pores - which faces the compartment filled with liquid and which plays a key role in the separation;
• the different types of membranes can be used:
• Opening gap is the space formed between the main surface of the rotating body and the surface of the membrane.
• Cell is a part of the separation device, preferably of cylindrical shape, having a diameter much greater than its length, and comprising a rotary body disposed between two membranes and an operating gap on either side of said body. ; it is limited on each face by a membrane.
• Permeate chamber is a part of the separation apparatus, preferably of cylindrical shape having a diameter much greater than its length, and comprising at least one porous support covered by a membrane on each of its two main faces and which serves support the membrane, receive and evacuate the permeate.
• Permeability is measured by the ratio of the permeate flow rate to the surface of the membrane passed through.
• Oxidative conditions is a state of the liquid which is characterized by non-stationary and possibly periodic variations of fields of speed, flow, flow and or partially, of pressure of said liquid under the action of controlled external forces.
• Clogging is a phenomenon limiting the effectiveness of any membrane separation device by reducing its permeability; this phenomenon resulting from the following effects: appearance of a layer of deposit of materials on the selective layer of the membrane; sealing the pores of the membrane with said materials; appearance of the polarization layer during the processing of solutions containing dissolved salts and / or macromolecules.
• Coarse prefiltration is a pretreatment of the liquid to be treated with the aim of removing large particles representing a part of the suspended matter, having a size of at least 20 micrometers, using conventional filtration methods.
• Another invention (document 3: WO-A-96/09986) relates to a method and an installation for treating liquids containing organic waste.
• the treatment process includes physico-chemical treatment stages as well as ultra- or microfiltration and then reverse osmosis. All the membrane treatment steps are of the conventional type, that is to say tangential.
• the pretreatment steps (sieving, coagulation, flocculation, oxidation, filtration etc.) make it possible to prolong the lifetime of the membranes during all the steps of membrane treatment.
• the resulting systems are very bulky and complex. Rotary body filtration devices have been described in recent patents
• WO-A-95/00231, WO-A-96/01676, WO-A-95/16508, WO-A-92/21425 and US-A-5,143,630 (documents 4 to 8, respectively). All these patents use rotary bodies placed in the vicinity of the membranes and intended to reduce their clogging. The devices described in these patents (documents 4 - 8) aim to reduce the replacement time of the membranes. It is proposed to use modules containing the membranes with their supports. Said modules are in themselves of a complex design but they are easy and quick to assemble and disassemble from the filtration system.
• WO-A-95/16508 relates to a shaft on which rotary bodies are fixed in a separation device.
• a rotary body is proposed having at least two blades which are fixed to said shaft by pivots. In operating condition, these blades assume a radial, that is to say unfolded, position. When replacing the membranes, the blades are folded back and allow the entire membrane module to be extracted.
• the high diameter of the shaft in a folded state of the blades reduces the useful surface of the membrane.
• the ratio D / d between the diameter of the blades in the unfolded position D and of the shaft with its folded rotary bodies d varies only from 2J to 2.6. Balancing this assembly when the shaft is rotating is problematic.
• the shape of the blades is determined by the requirement of maximum compactness in the folded position.
• the present invention aims to provide a separation apparatus with reduced clogging membranes comprising at least four fixed flat membranes and at least three rotary bodies close to the selective layer of said membranes, said bodies generating secondary vortices, and at least one means for generating oscillatory conditions in the liquid.
• Another object of the present invention is to provide a separation device in which each membrane is subjected to a vibratory movement in order to avoid or attenuate their clogging.
• Said apparatus having at least four membranes installed on two semi-fixed porous supports, being rigid and of simple construction, and each comprising at least one disc preferably made of sintered metal powder or any other suitable porous material.
• Said disc, covered on both sides by the membrane is animated by vibratory movements induced by the oscillatory variations of flow and pressure of liquid, on the one hand, and by the continuous rotary movement of the bodies threaded on the shaft , on the other hand.
• the superimposition of the vibrations of the membranes and the oscillations of liquid flow contributes to reducing the clogging of the membranes.
• Another object of the present invention is to extend the operating time of the separation system between two periods of washing membranes, to extend the period of use of the membranes, as well as to improve the performance of the membranes used.
• the use of the proposed construction of a rotating body having a helical shape makes it possible to distribute the load of materials eliminated by the membrane uniformly over its entire surface. This uniform distribution makes it possible to improve the efficiency of the membrane, on the one hand, and to avoid the formation of stagnant zones having a tendency to be clogged preferentially, on the other hand.
• Another objective of the present invention is to increase the load on the membrane of suspended solids beyond the values which can be determined by the "Silt Density Index” method (see document 9:
• Another objective of the present invention is to provide a universal separation system which can be applied for micro-, ultra, and / or nanofiltration as well as for reverse osmosis at low pressure.
• the liquid to be treated can be used without any pretreatment or with a weak pretreatment (only one coarse pre-filtration step).
• the aim of the pretreatment is to remove the liquid to be treated from the large particles, and this not to reduce the risk of clogging but to avoid any effect of mechanical aggression which could deteriorate the selective layer of the membrane.
• Another object of the present invention is to provide a method for separating liquids using said apparatus which can adapt to various particular constraints required.
• the same apparatus and the same separation system can be used for the following processes: microfiltration, ultrafiltration, nanofiltration and reverse osmosis, simply by using the appropriate membranes. Thanks to the high clogging resistance, the separation process can be proposed to achieve high concentrations of the product in question in the concentrate, on the one hand, and to treat highly concentrated liquids, on the other hand. For a large number of the liquids to be treated, it is no longer necessary to use additional reagents to delay the clogging of the membranes and thus prolong their operating time between washes. The absence of the pretreatment steps leads to a separation system which is simpler from the point of view of their use and more compact.
• Another objective of the present invention to increase the permeability reached of the membrane by preventing or attenuating a deposition of components of the liquid on the selective layer of the membrane.
• the high permeability of the membranes is maintained for a longer period of time. In total, these two factors improve the efficiency of the membrane separation device.
• a membrane separation device intended for separate the component (s) present in a liquid to be treated.
• the device is characterized in that it consists of a stationary enclosure having an axial symmetry, of at least four flat membranes in the form of a disc with a hole in the center through which is threaded a shaft on which are fixed at least three bodies arranged in the vicinity of said membranes and which shaft is driven in a rotational movement which drives said bodies.
• Said enclosure contains permeate chambers and cells arranged in consecutive alternation with respect to each other and crossed by the tree.
• Said shaft is set in motion by a motor or any other means by means of a transmission system.
• Each cell comprises a body threaded on the shaft and two spaces formed between said body and the surfaces of the membranes disposed on either side of said rotary body, which spaces are the operating interstices.
• the width of the operating gap varies between 0.5 and 50 mm, preferably between 1 and 6 mm.
• Said second end wall also comprising a device for fixing the shaft.
• the membranes separate the device into two compartments: the first contains the liquid and the second contains the permeate.
• the common introduction and evacuation devices are arranged in the opposite end walls between the shaft and the outer edge of said walls.
• the liquid can be additionally discharged from the first compartment of the device through at least one peripheral evacuation device disposed in the annular wall of each intermediate cell.
• the ratio of the liquid flow through the common drain device to the sum of the liquid flow rates through all the peripheral drain devices determines the relationship between the serial and parallel flows distributed among the different cells of the separation.
• the part of liquid which has passed through the membranes, the permeate fills the part of the separation device called the permeate chamber and is evacuated through the external edge of said chamber by at least one device for evacuating the permeate.
• the rotating bodies threaded on the shaft are placed in each cell of the device.
• These bodies preferably have the shape of a propeller having at least two blades linked to the central ring of said propeller.
• Each of said blades comprises two main surfaces, the curvature of which along the line of circumference can be negative, zero or positive.
• the curvature of the main surfaces of the blades of the propeller located in the intermediate cell is preferably zero.
• the curvature of the main surface of the blades of the propeller situated in the extreme cell is preferably positive (that is to say convex) for the surface which faces the common device of introduction (or of evacuation) and the curvature is zero for the surface facing the membrane.
• Said surfaces being limited by a leading edge and a beveled trailing edge, curved in a spiral, and by an edge of circumference or by an external edge.
• the bevelled and curved side edges in a spiral make it possible to reduce energy losses during the rotation of the propellers.
• the edge of the circumference being coaxial with the main axis of the shaft, a helix having said edge is preferably placed in each of the end cells.
• the external edge being non-coaxial with the main axis of the shaft, a helix having said edge is preferably placed in the intermediate cell.
• the geometry of the leading edge and the trailing edge is calculated by a formula defined below.
• N k ⁇ be a clamping angle of each of the two lateral edges determining the shape of each blade of the propeller (k is a coefficient). Then the shape of the leading edge and the trailing edge of a blade is described by the following equation:
• ⁇ is a current angle of the leading edge or the trailing edge of the blade
• m is an integer determining (in units of ⁇ t / ⁇ ) a starting angle of an edge with respect to the horizontal axis (abscissa) at the center of the circle enclosing the blades and constituting an edge of circumference of each helix
• n is a number of blades.
• the absolute value of ⁇ varies between 0 and N
• the coefficient k varies between 0.05 and 1, preferably between 0.1 and 0.6.
• the number of blades n can vary between 2 and 12.
• the angle between the leading edge and the trailing edge of each of the blades varies between 15 and 180 ° while the angle between the edge of attack of a blade and the trailing edge of the next blade can vary between 0 and 165 °.
• the ratio between the radius of the circumference of the blades and the radius of the outer edge of the central ring which supports said blades varies between 3 and 15.
• the speed of rotation of the propellers varies between 20 and 5000 revolutions per minute, preferably between 200 and 2500 revolutions / min and can be modified as desired during operation of the device.
• the phase of positioning the propeller in each of the intermediate cells with respect to each other can vary between 0 and 180 °.
• the propeller of an extreme cell of the apparatus contains blades with a leading edge and a trailing edge having the same shape as those of the propeller arranged in an intermediate cell. This form can also be calculated from equation (1).
• the flow of liquid momentarily decreases when the blade passes over the liquid introduction or evacuation device. These flux decreases occur periodically.
• the main surfaces of said blades preferably having a convex curvature with respect to said introduction (or evacuation) device make it possible to less suddenly reduce the flow of liquid passing through said devices and thus avoid a "water hammer".
• the proposed shape of the blades makes it possible to oscillate the flow of liquid by acting on the flow rate (and therefore the linear speed) of said liquid in the separation device.
• the curvature of the main surface, which faces the membrane can be reduced compared to the curvature of the opposite side.
• the phase of the positioning of the propeller in each of the extreme cells relative to each other can vary between 0 and 180 °.
• each blade of this propeller comprises two main surfaces which face the corresponding membrane, said main surfaces being limited by a leading edge and a beveled trailing edge preferably curved in a spiral in accordance with equation (1). Said outer edge having the shape of an arc being non-coaxial with the main axis of the shaft and that of the enclosure of the device.
• R p having the starting point which is preferably located on the median of the arc forming said outer edge of the blade, said median crossing the axis of rotation of the propeller. Since the radius R p must always have a length less than that of the radius R, the curvature of the outer edge of the propeller blade remains greater than that of the circle surrounding the blades and described by the end of the outer edge of the blade when the propeller rotates.
• the ratio R p / R is between OJ and 0.99, preferably between 0.7 and 0.95.
• An intermediate cell is preferably provided with at least one peripheral device for discharging the liquid fixed in the annular wall of said cell and having its main axis which forms an angle relative to an axis of position of the opening center in said annular wall between 0 ° and 90 °.
• Said peripheral evacuation device having said angle is preferably inclined in the direction of rotation of the propeller.
• the opening of said device located in the annular wall is adjacent to said end of the outer edge of the blade.
• the number of blades of the propeller of this latter construction must preferably be equal to the number of peripheral liquid discharge devices if the number of said discharge devices is greater than one.
• the angle formed between the extremum position lines on the outer edge of each blade must be equal to the angle formed between the positioning axes of the center of the openings of the peripheral evacuation devices.
• the blades being in continuous movement in the vicinity of the selective layer of the membranes and having the two lateral edges curved in a spiral have the role of: A. Generating a rotary movement of the liquid by giving it a high speed in the interstice of operating and making this speed more uniform over the entire surface of the membrane;
• the speed of rotation of the propeller determines the frequency of the oscillations, while the number and width of the blades at the level of the radius where there is an axis of the devices for introducing and discharging the liquid determine both the frequency and the amplitude of the oscillations.
• Said end propellers can be fixed on the shaft of the separation device so as to be in phase or in phase difference with respect to each other.
• the distance between the opening of the introduction and / or evacuation device and the main surface of the blade being adjustable or fixed.
• said chambers having a disc shape of thin thickness.
• a helix On each side of the porous support constituting said chambers is a helix, having at least two blades and being in rotation. If there is an offset between the phases of the two helices surrounding the same permeate chamber, there is a local pressure gradient on either side of said permeate chamber. Said gradient varies according to the movement of the helices and thus generates a vibration of said permeate chamber and of the membranes.
• the distance between the membrane surface and the main surface of a propeller blade i.e., the width of the operating gap
• the width of the operating gap can be constant along a radius and the line or may vary along these lines. In the latter case the angle between the surface of the membrane and the main surface of the blade is between 0 and 30 °.
• a rotary body having a helical shape containing at least two blades compared to a flat disc or a disc with grooves or projections has several advantages: a) to reduce the forces of friction between the surface of the rotating body and the liquid and, thus, to reduce energy losses and, therefore, to decrease the heating of the liquid during the operation of the separation device while preserving the speed necessary for shearing effective of the membrane surface by the flow of liquid; b) adding a second component in the periodic non-stationary movement acting on the semi-fixed support which generates a vibratory movement in the membranes; c) adding a third component in the periodic non-stationary movement of the liquid by means of the momentary and periodic partial closure of the device for discharging said liquid located in each cell of the separation device in its annular wall.
• the combination of these periodic non-stationary movements makes it possible to reduce the rate of deposition of the materials on the membrane and / or to improve their removal from the surface of the membrane.
• a permeate chamber consists of a porous support which comprises at least one porous disc, the main faces of which are covered by the membranes, generally made of polymer, and which disc has a hole in the center for threading a tree and let the liquid pass around the central rings of the propellers.
• Said support may also be composed of a sufficiently rigid porous material of the symmetrical, asymmetrical and / or composite type, the main surface (s) of which are (are) covered by a selective layer.
• the porous disc is preferably made of sintered metal powder. It can also be made of ceramic and / or metallo-ceramic. It can also be covered by a selective layer of polymer and / or ceramic and / or metallo-ceramic bonded to the support.
• the pore size of a porous disc varies between 1 and 500 micrometers and the porosity rate between 5 and 80%. It is essential that, on the one hand, the resistance to flow of the permeate is minimal and, on the other hand, the size of the pores does not deteriorate the structure and the integrity of the membrane used, even under differential pressure. important. At the same time the porosity rate of said porous disc must be optimal in order to maintain the rigidity of the support which must be sufficient for the particular operating conditions.
• the permeate leaves said chamber through the outer edge and through the part of the main surface adjacent to said outer edge, then it can be collected in a tank or exit by a device installed in the casing which surrounds each chamber.
• the support is provided with an internal edge coaxial with said external edge, said internal edge reserves a space through which a tree is threaded. This internal edge and the portion of the membranes in contact with said edge are sealed.
• Each of said chambers is fixed at its outer periphery to the annular wall of the adjacent cells, forming the enclosure of the separation device, and remains free at its central part.
• a single disc can be used as the permeate chamber covered on each of its faces by a membrane or by a selective layer bonded to said faces.
• the permeate chamber consists of pores located inside the porous disc and the liquid enters said chamber by crossing the membrane, then it flows through the pores inside the porous disc by going towards the outer edge at which it exits the separation device.
• the case of using a single porous disc as a permeate chamber can be envisaged for the reverse osmosis and / or nanofiltration and / or, sometimes, ultrafiltration processes, that is to say for the processes where the membranes have low permeability.
• At least two porous discs can be used for the permeate chamber.
• said porous discs are separated by stacking between them a grid, for example, or another porous disc.
• This grid or internal disc having pores of a larger size than that of the pores of the external supports.
• Each membrane used in the separation device is presented as a disk with a hole in the center. There is no junction between the different membranes of each cell as well as between the different portions of the membrane, which covers each side of the porous disc, beyond the outer edge and, therefore, the formation of zones is thus avoided. stagnation that could form in the places of said junctions.
• the seals used for sealing and located near the outer and inner edges of the support are well washed by the vortex of the liquid generated by the rotating bodies.
• the pore size d m of the selective layer of the membrane used in the separation apparatus and the pore size D s of the support which constitutes a permeate have the following ratio between them: D ⁇ d m ⁇ 50.
• the thickness of the permeate chamber is between 0.5 and 10 millimeters, preferably between 1 and 5 millimeters.
• the enclosure of the separation device has an axial symmetry with respect to the shaft.
• the latter is made of a material either and preferably solid, or hollow in the part which is inside the device and which is in contact with the liquid.
• the liquid enters under pressure into the separation device through a common introduction device and / or through an axial introduction device, flows around and or inside of the tree and fills the various cells including the operating gaps.
• Said hollow shaft containing at least one radial channel formed in its wall at the level of each porous support and serving to introduce the liquid into each of the operating interstices.
• Each of the rotary bodies comprising a central ring, said ring having at least one radial channel also serving to introduce the liquid into each of the operating interstices.
• Said channels of the central ring coincide in their position with the channels of the hollow shaft.
• Each internal cell is provided with at least one peripheral device for discharging the liquid.
• At the ends of the separation device provided with a hollow shaft are arranged end cells consisting of an extreme rotary body and a single membrane, on the one hand of said rotary body, and of a device for introducing the liquid (or device for discharging said liquid) from the other part of said rotary body.
• the rotary bodies of said end cells also having a helical shape play an additional role compared to those placed in the intermediate cells.
• a device for introducing the liquid is placed in the vicinity of the plane of rotation of said end propellers.
• the interruption of the jet of said liquid by the blades in rotary motion generates oscillations in the flow of said liquid throughout the separation device.
• the same role can be played by the other propeller located in the other extreme cell.
• the interruption of the liquid outlet jet by the blades in rotary motion generates an oscillation of the flow of said liquid throughout the separation device.
• Another source of liquid oscillations lies in the intermittent and periodic interruption of the flow of said liquid which leaves through at least one peripheral evacuation device located in the annular wall which surrounds each intermediate cell of the hollow shaft separation device.
• the reduction in the radius of the curvature of the outer edge of the blade relative to the curvature of the line of circumference of the propeller results in effective generation of the oscillatory conditions in the liquid at the level of the operating gap of the corresponding cell.
• the oscillatory conditions created in the hollow shaft separation device have an influence on the membranes used.
• the membranes are placed on the porous supports having a disc shape with a thickness which varies from 0.5 to 10 millimeters, thus forming the permeate chambers.
• the internal edge of said chambers is not fixed and therefore facilitates vibration of said permeate chambers and, therefore, of the membranes which cover the main faces of said supports.
• the wave which forms in the liquid under the effect of the oscillations caused by at least one helix of the extreme cells propagates from one extreme cell of the separation device to the other extreme cell by crossing each intermediate cell consecutively. of said device. There is therefore a local gradient in speed and pressure on either side of each permeate chamber. This gradient varies periodically and vibrates the membranes.
• Another source of vibration of the membranes lies in the positioning of the helices of the different cells with respect to each other. If there is a shift in the phases of the helices surrounding the same permeate chamber, there is a local pressure gradient on either side of said chamber. Said gradient varies periodically at each point of the membrane and of their support and thus generates the vibrations of said membranes.
• the membrane separation apparatus comprises:
• At least four flat membranes installed on two stationary porous supports on either side of said supports, said supports having the shape of a disc with a hole in the center;
• At least one common device for introducing the liquid into the first compartment said device located in the first end wall of said enclosure between the shaft and the outer edge of said wall being in direct communication with the first end cell;
• At least one device for discharging the liquid in the first compartment said device is located in the second end wall between the shaft and the outer edge of said end wall and / or in the annular wall which surrounds each intermediate cell;
• At least one device for evacuating the permeate in the second compartment said device located on the outer edge of said porous supports;
• At least three bodies arranged in the first compartment in the vicinity of said membranes by forming operating interstices; each of said bodies comprising a central ring threaded on
• the separation device according to this first embodiment could be used by introducing the liquid into the devices arranged in the second end wall and / or in the annular wall of each intermediate cell and by recovering it through the common device. disposed in the first end wall of the enclosure.
• the membrane separation apparatus comprises:
• At least four flat membranes installed on two stationary porous supports on either side of said supports, said supports having the shape of a disc with a hole in the center;
• At least one axial device for introducing the liquid into the first compartment said device located in the first end wall of said enclosure at the end of the hollow shaft;
• At least one device for discharging the liquid in the first compartment said device is located in the second end wall between the shaft and the outer edge of said end wall and / or in the annular wall which surrounds each intermediate cell;
• At least one device for evacuating the permeate in the second compartment said device located on the outer edge of said porous supports;
• At least three bodies arranged in the first compartment in the vicinity of said membranes by forming operating interstices; each of said bodies having a central ring; said ring of each body having at least one radial channel serving to introduce the liquid into each of the operating interstices; said bodies strung on
• a hollow shaft forming the axis of said enclosure and inserted into a central hole produced in said membranes and supports and driven by a continuous rotational movement which drives said bodies in rotation while forming in the liquid at said operating interstices of the secondary vortices and oscillatory conditions as well as vibratory movements of the membranes in order to avoid or attenuate their clogging and to maintain their permeability at a high level;
• said hollow shaft containing at least one radial channel formed in its wall at the level of each porous support and serving to introduce the liquid into each of the operating interstices; said channels of the central ring of the bodies coincide in their position with the channels of the hollow shaft;
• the separation device according to this second embodiment could be used by introducing the liquid into the devices arranged in the second end wall and / or in the annular wall of each cell and by recovering it through the axial device d 'disposal disposed in the first end wall of the enclosure at the end of the hollow shaft.
• the membrane separation apparatus comprises:
• At least four flat membranes installed on two stationary porous supports on either side of said supports, said supports having the shape of a disc with a hole in the center;
• At least two devices for introducing the liquid into the first compartment said devices located in the first end wall of said cylindrical enclosure; said first device is a common device for introducing a liquid into the first compartment, said first device located between the shaft and the outer edge of said end wall being in direct communication with the end cell for introducing the liquid; said second device is an axial device for introducing the liquid into the first compartment, said second device located at the end of the hollow shaft;
• At least one device for discharging the liquid in the first compartment said device is located in the second extreme wall between the shaft and the outer edge of said end wall and / or in the annular wall which surrounds each intermediate cell ;
• At least one device for evacuating the permeate obtained from said liquid in the second compartment said device located on the outer edge of said porous supports;
• the separation device according to this third embodiment could be used by introducing the liquid into the devices arranged in the second end wall and / or in the annular wall of each cell and by recovering it through the axial devices and / or common evacuation disposed in the first end wall of the enclosure.
• the stationary cylindrical enclosure and the shaft are in a horizontal position.
• the permeate collection tank, the device for fixing the shaft, and the common device for introducing the liquid may preferably be arranged in the extreme bottom wall of the device, the common evacuation device and the axial device for introducing said liquid located in the extreme top wall.
• This vertical construction allows for easier access to the membranes during their installation and / or replacement.
• the liquid enters the separation device through the common introduction device, located in the first end wall of the cylindrical separation device, passes around the shaft using for this the spaces between blades propellers by entering the same in each cell and therefore in each operating gap.
• the ratio between the current which flows along the shaft and that which passes through each gap can be adjusted by means of the valves connected to the common evacuation device and to the peripheral liquid evacuation devices.
• the objectives of the present invention are achieved by superimposing the rotary movements of the liquid driven by the propellers, the radial movements of said liquid and, finally, the oscillatory movements of said liquid. All of these movements overlap in the operating gap.
• said movements form, in the liquid located in the vicinity of the selective layer of the membrane, the conditions which produce an effect favorable to attenuation or even to prevention of deposition on the membrane.
• said oscillations existing in the liquid generate vibration movements of the membrane itself, which makes it possible to avoid an accumulation or even to extract the materials which have penetrated into the pores of the membrane.
• Said oscillatory conditions in the liquid, causing a vibratory movement of the membrane can be distinguished by their origin: a) the waves which propagate through the separation device from one cell to another and which are formed by the rotation of the extreme propellers with regard to the common device for introducing the liquid and or with regard to the common device for discharging the liquid; b) the waves which form in each cell by means of a paddle-wheel propeller which momentarily and periodically interrupts the flow of liquid in said cell; the propagation volume of these latter waves is essentially limited to the volume of said cell.
• the operation of the membrane separation apparatus proposed in the present invention requires little or no washing. Optimization of hydrostatic (pressure) and hydrodynamic parameters (liquid flow in the device, components of speed in the operating gap), frequency and the amplitude of the oscillations of each liquid to be treated as well as the parameters of vibratory movements of the membranes, suitable for the treatment of said liquid to be treated, makes it possible to maintain the permeability of the membranes at a high level for an extended period.
• the frequency of oscillation of liquid must be between 0.1 and 1000 Hz, preferably between 1 and 400 Hz.
• the various periodic actions generated simultaneously in the separation apparatus and in each cell of said apparatus must preferably have a phase shift being not in quadrature with respect to each other to avoid the formation of stagnant zones.
• valves can be installed upstream and / or downstream of the separation device; said pumps are installed, in general, upstream of the separation device
• an electric field applied on both sides of each membrane in the separation device in order to further decrease the polarization of concentration in reverse nano- and ultrafiltration osmosis, reduce or avoid the appearance of the adsorption layer and or of a pore-filling phenomenon in micro- and ultrafiltration, one can use an electric field applied on both sides of each membrane in the separation device.
• a helix and a porous metallic support for the membrane are used as opposite electrodes.
• Said electrodes are preferably covered by a layer of silver and / or platinum.
• the voltage of the electric field can be continuous or alternating or else of the pulsed type.
• the application of the electric field using a direct current whose application varies in time discontinuously is preferable.
• the field voltage is constant for the pre-selected duration and then drops to the minimum value or even to zero. At the end of this "dead period" the tension appears again.
• There is a minimum threshold of the electric field voltage which is generally equal to a convection force existing in each operating gap due to the differential pressure applied on either side of the membrane. Said force causes the components which cannot pass through the pores of the membrane, to be deposited on the selective layer of the latter.
• Another possible cause of said threshold is an electrical resistance of the operating gap and of the filtering medium.
• an electric field having a voltage above said threshold must be used.
• the voltage of the continuous electric field beyond said threshold is between 500 and 50,000 V / m.
• the ratio between the duration of application of said voltage and the duration of the dead period is between 0.1 and 50.
• the present invention also relates to a separation system which comprises:
• a membrane separation device at least one device for forming the differential pressure on either side of the membranes, said device is preferably located upstream of the separation device ⁇ w the pipe for introducing the liquid into said device and / or into driving the permeate;
• the liquid is prepared in the concentration tank from the liquid to be treated by means of the removal of the permeate from said liquid to be treated in the separation apparatus.
• the permeate is directed to the permeate receiving tank.
• the liquid to be treated is introduced into the concentration tank through, preferably, the level regulator. This step is the concentration phase of the liquid to be treated.
• the presence of the concentration tank allows the separation system to operate continuously by treating a large volume of the liquid to be treated. Of course, this system could be used by treating the liquid to be treated batchwise, that is to say by tarpaulins whose volume is equal to that of the concentration tank.
• Said concentration phase is characterized by the closing of the concentrate drain valve.
• the liquid is concentrated by circulating under pressure through the circulation loop.
• This concentration phase lasts until the desired concentration rate is obtained.
• the concentrate drain valve opens and the concentrate drain pump starts to evacuate the concentrate from the system to the concentrate drain tank. From this moment begins the separation phase.
• the purge flow of the concentrate discharged into the concentrate purge tank is measured by a flow meter installed in the purge line.
• the concentrate purge flow must remain proportional to the flow of the permeate discharged into the permeate receiving tank and measured by a flow meter. The proportionality coefficient is given at the start of the separation process. This constancy of the concentration rate must be preserved throughout the duration of the liquid separation phase.
• the flow meters installed in the permeate line and the concentrate purge line are connected to the respective pumps by regulating the flow rates of said pumps according to desired proportionality ratios.
• a pump it is possible to use, for example, a piston pump with proportional signal which manages the flow rate of the concentrate in a manner proportional to that of the permeate.
• the hydraulic balance in the treatment system is maintained correctly in the simplest way by means of a level regulator placed in the concentration tank of the liquid to be treated. Thanks to this regulator, the addition of the liquid to be treated in the concentration tank follows the sum of the purge flow rates of the concentrate and the permeate.
• a level regulator placed in the concentration tank of the liquid to be treated. Thanks to this regulator, the addition of the liquid to be treated in the concentration tank follows the sum of the purge flow rates of the concentrate and the permeate.
• sensors arranged in the pipes and tanks of the separation system allow to follow the evolution of the parameters of the liquids, for example: concentration, pH, temperature, pressure, conductivity etc.
• the liquid separation system can include several other components such as, for example, a sterilization subsystem of the separation apparatus, a pre-filtration subsystem for clarifying the liquid to be treated with its own washing subsystem , a circulation loop having a circulation pump in which the liquid circulates under the operating pressure of the separation device, a permeate suction pump, pressure switches to maintain the operation of the system in the desired pressure range , automation and a supervision system.
• the pre-treatment subsystem of the liquid to be treated can also be included in the treatment system and can contain one or more phases of precipitation, coagulation, adsorption, micellization. All the sensors can be connected to programmable automata which control the machines (pumps, valves, motors) and are themselves supervised by a computer from which the control settings can be modified.
• the separation system is universal and can be applied for micro-, ultra-, and / or nanofiltration as well as for reverse osmosis at low pressure.
• the liquid to be treated can be used without any pretreatment or with a weak pretreatment (coarse pre-filtration) to avoid deterioration of the selective layer of the membranes by large particles.
• Said system can be installed in a fixed position or made mobile.
• the present invention also relates to the process for separating the liquid to be treated, on the one hand into a permeate or filtrate devoid of part or all of the materials which cannot pass through the pores of the membrane, and on the other hand, in a concentrate enriched in said materials, said process comprising the following steps:
• the liquid is discharged under pressure into the first compartment of the separation device by at least one common introduction device by filling all the cells, including the operating interstices, and it is extracted therefrom by at least one common device d evacuation of the liquid.
• at least one common introduction device by filling all the cells, including the operating interstices, and it is extracted therefrom by at least one common device d evacuation of the liquid.
• Said ratio must be between 0.05 and 0.99, preferably between 0.7 and 0.9.
• a serial circulation of the liquid takes place when the said liquid enters the separation device through the common introduction device, successively passes all the cells of the device and then exits through the common evacuation device located in the second end wall of the cylindrical enclosure.
• the peripheral evacuation devices located in the annular wall of each cell, in general in the upper zone, are only used to let the air pass while the separation device is filled with the liquid; and the liquid flow oscillations are formed by the propellers located in the extreme cells with regard to the liquid introduction and evacuation devices.
• a parallel circulation of the liquid takes place when the said liquid enters the separation apparatus through the axial device for introducing the hollow shaft provided with the radial channels situated at the level of each porous support of the separation apparatus.
• the liquid passes through the shaft and each radial channel and enters directly into each cell.
• the liquid leaves the device using the peripheral evacuation devices.
• the oscillations are generated by the propellers located in each cell of the separation device.
• the third possible case includes the superposition of the two modes of circulation of the liquid in series and in parallel. Thanks to the use of propellers with blades, the choice between serial and parallel current and the ratio between said two currents in the different cells of the separation device can be modulated.
• the liquid to be treated can be used without any pretreatment or with a weak pretreatment (coarse pre-filtration) to avoid deterioration of the selective layer of the membranes by large particles.
• - Figure 1 is a longitudinal sectional view schematically showing a separation device according to the first embodiment of the invention
• - Figure 2 is a longitudinal sectional view schematically showing a permeate chamber according to the first construction
• FIG. 3 is a longitudinal sectional view schematically showing a permeate chamber according to the second construction
• FIG. 4 is a longitudinal sectional view schematically showing a permeate chamber according to the third construction
• - Figure 5 is a longitudinal sectional view schematically showing a separation device according to the second embodiment of the invention
• - Figure 6 is a longitudinal sectional view schematically showing a separation device according to the third embodiment of the invention.
• FIG. 7 is a longitudinal sectional view schematically showing a separation device according to the vertical construction of the third embodiment of the invention.
• FIG. 8 is a front view of an intermediate propeller of the first construction which operates in an intermediate cell of a separation device
• FIG. 9 is a cross-sectional view of a blade of the intermediate propeller which corresponds to a line 2-2 of section in Figure 8;
• - Figure 10 is a front view showing an end propeller which operates in an end cell of a separation apparatus;
• - Figure 11 is a sectional view of a blade of the extreme propeller of the first construction which corresponds to a line 4-4 of section in Figure 10 at the time of passage with regard to the common device of introduction / d 'evacuation of the liquid
• - Figure 12 is a sectional view of a blade of the extreme propeller of the second construction which corresponds to a line 4-4 of section in Figure 10 at the time of passage with regard to the common device of introduction / d 'evacuation of the liquid;
• - Figure 13 is a front view showing an intermediate propeller of the second construction which operates in an intermediate cell of the separation apparatus;
• - Figure 14 is a cross-sectional view of the intermediate cell of the separation apparatus containing an intermediate propeller of the second construction and two peripheral devices for discharging the liquid;
• FIG. 15 illustrates a schematic diagram of the liquid separation system using a membrane separation device, as well as a membrane washing subsystem.
• the separation device 1 comprises a stationary cylindrical enclosure 2 separated by the membranes into two compartments.
• the first, compartment 10 contains the liquid, the second, compartment 20, the purified liquid, that is to say the permeate or the filtrate.
• Said separation apparatus comprises: WO 99/26717 _ ⁇ _ PCT / FR98 / 02475
• At least one common device 30 for introducing the liquid fixed in the first end wall 3 between the shaft 12 and the outer edge of said end wall, said device 30 being in communication with the end cell 8 for introducing the liquid,
• each intermediate cell 11 of the device there is preferably at least one peripheral device 41 for discharging the liquid.
• the ratio between the flow of liquid through the device 40 and the sum of the flow of liquid through the devices is preferably at least one peripheral device 41 for discharging the liquid.
• the tank 60 allows the collection of the permeate which leaves the different permeate chambers 21 and which can be evacuated through the permeate recovery device 62.
• the cells 8, 9 and 11 and the chambers 21 are alternately stacked around the shaft full 12.
• the assembly forming the separation device 1 which consists of at least three cells 8, 9 and 11 and at least two permeate chambers 20.
• the annular walls of said cells and the chambers both have a disc shape and fit into the same cylindrical enclosure 2.
• the shaft can be rotated by a motor 13 by means of a transmission system 14.
• Each of said cells contains a propeller 15, 17, 18 fixed on the 'solid shaft 12 and rotated using this shaft.
• the motor 13 or another means for rotating the shaft may have a single speed of rotation, several speeds of rotation or a speed of rotation may be variable during the operation of the separation device.
• the liquid is introduced into the apparatus 1 by means of the common introduction device 30 facing the blades of the end propeller 17 where the flow of liquid is subjected to an oscillation by virtue of the rotation of said propeller.
• the liquid is evacuated from the device by means of the common evacuation device 40 facing the blades of the extreme propeller 18 where the stream of liquid is also subjected to oscillation by means of a rotation of said propeller. These oscillations propagate throughout the separation apparatus.
• each intermediate cell 11 the liquid is subjected to an oscillation by virtue of a momentary and periodic partial interruption of the flow of said liquid when the blade of the rotary propeller 15 passes opposite the peripheral evacuation device 41 located in the annular wall of said cell.
• the separation apparatus comprises at least one intermediate cell 11 comprising two membranes 22 on either side of a body 15 having the shape of a helix.
• the liquid is in radial flow in the operating gap 16 formed between the main surface of the blades of the propeller 15 and the selective layer of the membrane 22.
• a rotary movement of the liquid is superimposed to radial flow resulting in a spiral flow: formation of vortices or vortices.
• Each of the two extreme cells 8 and 9 contain respectively the propellers 17 and 18 and a single membrane, on the one hand of said propeller, and a common introduction device 30 or a common evacuation device 40, on the other hand.
• FIG. 2 is illustrated a longitudinal sectional view of a permeate chamber of the first construction consisting of at least one porous support 71 having a disc shape provided with a hole in the center for inserting a solid shaft 12 , the central rings 90 of the propellers 15 and allowing the liquid to pass around said rings.
• the porous support is preferably made of sintered metal powder. It can also be ceramic and or metallo-ceramic. Said support is covered on each of its faces by the membrane 22 preferably made of polymer.
• the permeate chamber is sealed at the level of the annular wall 78 of the adjacent cells all along the outer edge 72 by two seals 75 arranged on the surface of the membrane in the vicinity of said edge on either side of the porous support 71.
• an external portion 77 of the main surface of the porous support 71 said external portion is at the periphery of the joint 75.
• a single porous disc can be used as the permeate chamber covered on each of its faces by a membrane or by a selective layer bonded to said faces (see FIG. 2).
• the permeate chamber consists of pores located inside said disc and the liquid enters the permeate chamber by passing through the , carefully count __ PCT / FR98 / 02475
• This casing is preferably made of elastic material which can be easily clamped around the enclosure of the separation device and which generally only has to withstand a small pressure inside. This is the case of using the device, provided with the permeate chambers of the first construction, for the reverse osmosis and / or nanofiltration and / or, sometimes, ultrafiltration processes.
• FIG. 3 shows longitudinal sections of the permeate chambers according to the second and third constructions, respectively.
• the same references have been used as in FIG. 2 to represent the elements common to the three constructions.
• These two constructions comprise two external porous discs 81 and 82 covered on their external face by the membranes 22.
• the porous discs can be separated by a grid 83 (FIG. 3), by example, or by an internal porous disc 84 (FIG. 4) having pores of larger size than that of the pores of the layers 81 and 82.
• the permeate leaves, preferably through the outer edge 85 of the grid or the outer edge 86 of said support with larger pores.
• Each membrane used in the separation device 1 is presented as a disc having a hole in the center. It is fixed in leaktight manner at the internal edge 79, 87 and 88 of the supports of each construction by an integral seal 76 and at the external edge by a seal 75 between the membrane 22 and the annular wall 78 of each cell 8, 9 and 11.
• Figure 5 is shown schematically a separation device according to the second embodiment of the invention.
• the same references have been used as in Figure 1 to represent the elements common to the two embodiments of the membrane separation apparatus.
• the separation device comprises an axial device 31 for introducing the liquid, said device being in communication with the hollow shaft 19 is located in the first end wall 3 of the device 1.
• the liquid in each of the cells of the separation apparatus is used the radial channels 32 made in the wall of the shaft at each permeate chamber and the radial channels 33 made in the central ring 90 of each of the propellers.
• the propellers are arranged on the shaft so that said channels in the wall of the shaft and in the central rings of the propellers coincide.
• the liquid leaves the separation device through the common evacuation device 40 where the current is subjected to oscillations thanks to the rotation of the extreme propeller 18.
• the liquid is subjected to oscillations thanks to the temporary and periodic partial interruption of the flow of said liquid when the blades of the rotary propeller 15 pass over the peripheral evacuation device 41 located in the annular wall of said cell.
• FIG. 6 is shown schematically a separation device according to the third embodiment of the invention.
• the separation apparatus comprises two devices for introducing the liquid 30 and 31.
• This separation apparatus represents a synthesis of the first and of the second embodiment of the invention and can be used to better regulate the relationship between the liquid flows that pass through each cell in a serial and parallel fashion.
• FIGS. 1, 5 and 6 are shown horizontal separation devices (the enclosure and the shaft being horizontal), a membrane separation device could be produced which is arranged vertically and which is shown at as an example in FIG. 7 (for the third embodiment).
• the permeate is collected using the tank 63 provided with the common device 64 of recovery of the permeate or using the casing 74 surrounding each permeate chamber 21 and provided with a permeate evacuation device 73 (the casing 74 and the device 73 are shown, for example, on a single chamber permeate).
• the liquid is introduced into the separation apparatus in accordance with this third embodiment by means of the common introduction device 30 facing the blades of the extreme propeller 17 where the current is subjected to oscillations thanks to the rotation of said propeller.
• the liquid is evacuated from the device 1 by means of the common evacuation device 40 facing the blades of the extreme propeller 18 where the current is also subjected to oscillations thanks to the rotation of said propeller. These oscillations propagate throughout the separation apparatus.
• the liquid is subjected to oscillations by virtue of a temporary and periodic partial interruption of the current of said liquid when the blades of the propeller 15 pass over the peripheral evacuation device 41 located in the annular wall of said cell .
• the rotary bodies 15, 17 and 18 of a separation device of the present invention are preferably propellers having at least two blades.
• Figures 8 and 9 show an intermediate propeller of the first construction, said propeller being located in an intermediate cell 11.
• Each blade 96 being linked to the central ring 90 has two main surfaces 91 and 92 each facing the surface of the corresponding membrane. Said main surfaces are limited by a leading edge 93 and a trailing edge 94 bevelled and curved in a spiral, and a circumference edge 95 inscribed in a circle determining the diameter of said propeller and the length of said blades.
• ⁇ is a current angle of an edge 93 or 94 determining each lateral side of the blade; m is an integer determining (in units of ⁇ ) a starting angle of an edge relative to the horizontal axis (abscissa) at the center of the circle enclosing the blades; n is the number of blades.
• the absolute value of ⁇ varies between 0 and N.
• Figure 8 shows by way of example one of the possible constructions of said propeller having three blades arranged at 120 ° relative to one another. The preferred direction of rotation of this propeller is clockwise through relative to the plane of the drawing shown in FIG. 8.
• the number of blades n can vary between 2 and 12.
• the angle ⁇ , angle between the leading edge and the trailing edge, of each of the blades varies between 15 and 180 °, while the angle ⁇ between the leading edge of one blade and the trailing edge of the next blade can vary between 0 and 165 °.
• the ratio R / r between the radius R of the circumference of the blades and the radius r of the outer edge of the central ring 90 which supports said blades varies between 3 and 15.
• FIG. 10 illustrates, by way of example, said four-blade propeller 97.
• the curvature of the leading edge 93 and the trailing edge 94 is similar to that of the intermediate propeller and can be calculated from equation (1).
• FIGS. 11 and 12 show cross-sectional views of an extreme propeller blade which corresponds to a line 4-4 of section in FIG. 10.
• a blade of each construction comprises two main surfaces 111 and 112, 121 and 123.
• the cuts along line 4-4 were made at the time of the passage of the blade with regard to the common device 30 for introducing or discharging the liquid (the example represented in these figures shows a blade d propeller in the vicinity of the common device 30 for introducing the liquid).
• the minimum distance / between the main surface 112 or 123 and the orifice of the device 30 and / or 40 can be adjusted.
• the flow of liquid momentarily decreases when the blade passes over said liquid introduction or evacuation device.
• the main surfaces 112 and 123 of said blades having a convex curvature facing the introduction (or evacuation) device make it possible to less suddenly reduce the current of liquid passing through said devices.
• the proposed shape of the blades makes it possible to oscillate the flow of liquid by acting preferentially on the flow rate (and, therefore, the linear speed) of said liquid in the separation apparatus 1.
• the curvature of the main surface 121 of the blade, which faces the membrane can be reduced compared to that of the face 123 as illustrated in FIG. 12.
• Each blade 128 of this propeller has two main surfaces which make facing the corresponding membrane, said main surfaces being limited by a leading edge 93 and a trailing edge 94 both bevelled and curved preferably according to the spiral described by equation (1), and an outer edge 133.
• L end 134 the furthest from the axis 126 of rotation of the propeller, being on the outer edge 133 and having the radius R p , is at the same time on the line of circumference 135 having the radius R, which line 135 is formed when the propeller rotates.
• Said end 134 is preferably located on the median 124 of the arc forming the outer edge 133 of the blade 128, said median crosses the axis 126 of rotation of the propeller and the point 127 of departure of the radius R p .
• the radius R p is always smaller than the radius R.
• the curvature of the outer edge 133 of the helix is greater than that of the line of circumference 135.
• An intermediate cell is provided with at least one peripheral device 41 for evacuating the liquid fixed in the annular wall 78 of said cell and having its main axis 125 which forms an angle ⁇ with respect to the axis 129 of position of the center d opening in said annular wall.
• Said angle ⁇ is between 0 ° and 90 °.
• Said peripheral evacuation device having said angle is preferably inclined in the direction of rotation of the propeller.
• FIG. 14 by way of example, there is shown a section of the cell carrying two peripheral evacuation devices 41 turned in a different manner with respect to an axis 129.
• the present invention also relates to a liquid separation system which includes the membrane separation apparatus.
• Figure 15 shows a schematic diagram of the liquid separation system as well as a membrane washing subsystem.
• This separation device 1 comprises the devices 30 and 31 for introducing the liquid, connected to the line for introducing the liquid 151, as well as the devices for discharging the liquid 40 and 41, connected to the line for circulating the liquid 152 and to the concentrate drain line 172.
• the liquid to be treated is introduced into the tank 161 through the line 160.
• the liquid is prepared from liquid to be treated in the tank 161 for concentrating the liquid to be treated by means of the elimination of the permeate, directed towards the tank 162 of reception. Said removal of the permeate takes place during the separation of said liquid on the membranes installed in the separation device 1. This step is called the phase of concentration of the liquid to be treated.
• the presence of the tank 161 allows the separation system to operate continuously by treating a large volume of the liquid to be treated (said volume may be much greater than that of the tank 161).
• this system could be used by treating the liquid to be treated batchwise, that is to say by tarpaulins, the volume of which can be equal to that of the tank 161.
• Said concentration phase is characterized by the closing of the concentrate drain valve 171 installed on the concentrate drain line 172.
• the liquid is concentrated by circulating under pressure through the loop (lines 151 and 152) thanks to the opening of the liquid suction valve 150, the common liquid introduction valve 149 and / or the axial valve liquid 148, the common liquid discharge valve 170 and / or the peripheral liquid discharge valve 145.
• This concentration phase lasts until the desired concentration rate is obtained.
• the drain valve 171 of the concentrate opens and the pump 173 starts to evacuate the concentrate from the system to the drain tank 175 of the concentrate. From this moment begins the separation phase.
• the purge flow rate of the concentrate discharged into the tank 175 is measured by a flow meter 174.
• the flow rate of purge of the concentrate determined by the pump 173 must remain proportional to the flow rate of the evacuated permeate measured by the flowmeter 164, and determined by the pump 168 downstream of the common recovery device 62 on the pipe of the permeate 163.
• the proportionality coefficient is given at the start of the separation process This constant level of the concentration rate must be preserved throughout the duration of the liquid separation phase.
• the flowmeters 164 and 174 are connected to the pumps 168 and 173 by a circuit 176 which makes it possible to control the said pumps while maintaining the desired flow ratio.
• a proportional signal piston pump can be used to do this, for example, which manages the flow rate of the concentrate in proportion to that of the permeate.
• the hydraulic balance in the treatment system is maintained correctly in the simplest way by means of a level regulator 169 of the liquid in the concentration tank 161. Thanks to this regulator the addition of the liquid to be treated from line 160 follows the sum of the concentrate purge flow and the permeate flow.
• the separation device is generally inserted in a loop (lines 151 and
• the parameters of the liquid to be treated are measured by the concentration sensors 181 and of pH 182.
• the same liquid parameters are measured by the sensors 183, 184 and the temperature using thermometer 185.
• the pressure is measured by the pressure gauges 180 at the inlet of the separation device, 186 and 187 at the outlet of the liquid respectively upstream and downstream of the pressure reducer, 196 at the exit of the permeate.
• the temperature at the inlet and outlet of the heat exchanger is measured by thermometers 188 and 189, respectively.
• the final concentration of the purged concentrate is measured by the sensor 190 and the instantaneous concentration at the outlet of the device 1 is measured by the sensor 191.
• the same permeate concentrations are measured by the sensors 192 and 193, respectively.
• the membrane washing subsystem used in the separation apparatus comprises a tank 166 containing a washing solution and provided with sensors 194 and 195 for measuring the concentration and the pH respectively.
• the washing solution is sucked from the tank 1 6 through the line 177 through the valve 178 and then discharged through the separation device under a minimum differential pressure.
• the valve 167 installed in the pipe of the permeate 163 is closed and the valves 145 and 170 in the liquid evacuation pipes are opened as much as possible.
• the valve 171 remains closed and the holder 154 does not open due to the low differential pressure of the liquid on either side of said regulator.
• the present invention also relates to a process for separating liquids into a permeate devoid of the part or all of the materials which cannot pass through the pores of the membrane, on the one hand, and into a concentrate, enriched in said materials, on the other hand.
• This process includes the following steps (see Figures 1, 5 and 15):
• peripheral valves 145 By means of closing or opening the peripheral evacuation devices 41 of the simulated liquid in each intermediate cell using peripheral valves 145 distribute the serial and parallel flows among the different cells so as to reach the rate concentration desired optimally from the point of view of the thermal regime of said liquid.
• a serial circulation of the liquid takes place when said liquid enters the separation device through the common introduction device 30 located in the first end wall of the enclosure, successively passes all the cells of the device and exits at through the common evacuation device 40 located in the second extreme wall of the enclosure.
• a parallel circulation of the liquid takes place when said liquid enters the separation device through the axial introduction device 31 of the hollow shaft 19.
• the liquid passes through the shaft and each radial channel and enters directly into each cell.
• the liquid leaves the separation device using the peripheral evacuation devices 41.
• the same separation device could be used by introducing the liquid into the devices 41 and recovering it through the device 31.
• the third possible case includes the superposition of the two modes of circulation of the liquid in series and in parallel.
• the valves 148 and 149 are used in the introduction pipe 151 and the valves 145 and 170 in the circulation pipe 152 for the liquid.
• the variation in the flows between said introduction and evacuation devices makes it possible to effect the desired relationship between the allele and serial flows within each cell of the separation device.
• the peripheral valves 145 can be open on the whole of the cells or in a chosen manner on a certain number of the cells. On each cell there can be at least one peripheral evacuation device 41 connected to the pipe 152 through the peripheral valve 145.
• the serial currents and parallel can be adjusted as desired (for example, to achieve a necessary concentration of a compound or of a component considered while preserving the thermal regime in the separation apparatus).
• the same separation device could be used by introducing the liquid into the devices 40 and 41 by recovering it through the devices 30 and 31. From the experience obtained, the following non-restrictive and non-exhaustive applications can be proposed. of the apparatus, system and method described in the present invention:

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• 1997
  • 1997-11-26 FR FR9714825A patent/FR2771305B1/fr not_active Expired - Fee Related
• 1998
  • 1998-11-19 EP EP98955699A patent/EP1044061A1/de not_active Withdrawn
  • 1998-11-19 US US09/555,063 patent/US6613231B1/en not_active Expired - Fee Related
  • 1998-11-19 JP JP2000521911A patent/JP2002520131A/ja active Pending
  • 1998-11-19 BR BR9815054-5A patent/BR9815054A/pt not_active IP Right Cessation
  • 1998-11-19 CA CA002312783A patent/CA2312783A1/fr not_active Abandoned
  • 1998-11-19 AU AU12449/99A patent/AU747489B2/en not_active Ceased
  • 1998-11-19 WO PCT/FR1998/002475 patent/WO1999026717A1/fr not_active Ceased

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