Classifications

• • 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
  • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
  • B01D61/366—Apparatus therefor
• • 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
  • B01D61/36—Pervaporation; Membrane distillation; Liquid permeation
  • B01D61/364—Membrane distillation
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F1/00—Treatment of water, waste water, or sewage
  • C02F1/44—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis
  • C02F1/447—Treatment of water, waste water, or sewage by dialysis, osmosis or reverse osmosis by membrane distillation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/06—Specific process operations in the permeate stream
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/25—Recirculation, recycling or bypass, e.g. recirculation of concentrate into the feed
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2311/00—Details relating to membrane separation process operations and control
  • B01D2311/26—Further operations combined with membrane separation processes
  • B01D2311/2674—Condensation
• • 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
  • B01D2313/22—Cooling or heating elements
• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
  • C02F2103/08—Seawater, e.g. for desalination

Definitions

• TITLE Device and method for purifying a fluid in liquid phase
• the technical field of the invention is that of the purification of a liquid.
• the invention relates to the production and collection of purified fluid in the liquid state from the same unpurified fluid (e.g. containing a solute), by thermal distillation.
• the invention relates to the production and collection of purified water from water containing a solute (e.g. salt water or water loaded with minerals or polluted water).
• membranes defined as porous membranes, permeable to gases and impermeable to liquids. These membranes are used between two environments of different temperatures, the environment at the highest temperature being referred to as the “hot environment” and the environment at the lowest temperature being referred to as the “cold environment”, conventionally.
• the temperature difference between the hot medium and the cold medium induces a difference in vapor pressure between these two mediums, and this results in an exchange between the two mediums, which through, or perpendicular to a semi-permeable membrane takes place in the vapor phase, from the hot medium to the cold medium.
• This vapor after passing through a semi-permeable membrane, condenses in the cold medium and this results in a dilution of the liquid cold medium by the condensate of this vapor, which has become liquid.
• a flow of cold fluid is added to the cold medium and a flow of hot fluid to the hot medium, making it possible to produce, from a hot liquid at a first concentration of a first solute, a cooled hot liquid that is more concentrated in the hot hydraulic circuit after having passed through the hot medium delimited by the membrane and a reheated and diluted cold liquid.
• This structure constitutes a heat and purified fluid exchanger between the hot medium and the cold medium considered, known from the prior art.
• a first pressure reducer or hot pressure reducer such as for example a first nozzle or hot nozzle
• a second pressure reducer or cold pressure reducer such as for example a second nozzle or cold nozzle
• the invention offers a solution to the problems mentioned above, by proposing a device for purifying fluids in a simple and effective manner, while consuming little energy.
• One aspect of the invention thus relates to a device for purifying a fluid in liquid phase.
• the device comprises: a nozzle for distributing said fluid in the form of drops in an atmosphere; a wall of a condenser; and a membrane permeable to said fluid in the gas phase and impermeable to said fluid distributed in the form of drops in the atmosphere, the membrane being arranged between the nozzle and the wall of the condenser;
• the condenser wall and the membrane define a first space
• the membrane separates the first space from a second space comprising the nozzle
• the condenser comprises a circuit for circulating a refrigerant fluid
• the condenser wall separating the circuit for circulating the refrigerant fluid and said first space
• the condenser wall being impermeable to the fluid in liquid phase and in gas phase and being configured to condense the fluid in gas phase passed through the membrane into a liquid phase of purified fluid.
• nozzle is meant an element capable of dividing a liquid into drops and of expelling the drops into an atmosphere (in other words, of distributing the liquid in the form of drops into an atmosphere or a medium).
• condenser is meant an apparatus capable of condensing (or liquefying) vapor.
• refrigerant fluid is meant a fluid capable of cooling, typically having a temperature lower than the dew point temperature of the vapor circulating in the space between the membrane and the condenser.
• Such a device makes it possible to implement thermal distillation, i.e. an evaporation-condensation cycle of a fluid containing a solute or a non-volatile component or less volatile than the fluid, the concentration of the solute increasing in the part of the fluid that does not evaporate during the cycle and decreasing (or even being completely eliminated) in the part of the fluid that evaporates and then condenses.
• the term “purified fluid” or “pure fluid” designates the fluid obtained by evaporation-condensation during thermal distillation.
• the part of the fluid that does not evaporate is a fluid that is more concentrated in solute, in other words even less purified.
• the fluid that we want to purify is called “unpurified fluid” or “non-pure fluid” and can be, for example, water containing minerals such as calcium, magnesium or salt (hereinafter referred to in a simplified manner as “salts”), for example water from a distribution network, sea water or polluted water.
• unpurified fluid water containing minerals such as calcium, magnesium or salt (hereinafter referred to in a simplified manner as “salts”), for example water from a distribution network, sea water or polluted water.
• fluid is meant a fluid in liquid phase (also simply called “liquid”) or in gas phase (also called “gas” or “vapor”).
• liquid phase also simply called “liquid”
• gas phase also called “gas” or “vapor”.
• drops of unpurified liquid placed at a first temperature can be distributed via the nozzle into an atmosphere between a pressurized inlet and an outlet at atmospheric pressure of the nozzle, which causes a formation of vapor in the atmosphere in addition to the drops.
• the vapor corresponds to a gaseous phase of the purified fluid.
• a portion of the vapor naturally migrates to the condenser (or cold trap) which is placed at a second temperature lower than the first temperature, to be condensed at atmospheric pressure into drops of purified liquid on a cold impermeable wall of the condenser.
• the semi-permeable membrane arranged between the nozzle and the wall of the condenser makes it possible to separate the vapor of purified fluid from the drops of unpurified fluid, so that only a purified portion of the fluid distributed in the form of drops reaches the space delimited between the wall of the condenser and the membrane, so that the purified portion of the fluid is not "contaminated” with the unpurified fluid which circulates on the other side of the membrane (on the side where the nozzle).
• This membrane operates at equal pressure (for example, at atmospheric pressure) on both sides, and is therefore mechanically under little stress. Thus, it does not require any particular mechanical properties, which reduces its production cost.
• the term “impermeable to fluid distributed in the form of drops” corresponds, in the context of the invention, to a property of the membrane according to which the drops of liquid do not pass through the membrane when the device is in operation (and in particular when fluid is distributed in the form of drops by the nozzle).
• a non-absorbent membrane for drops of liquid a membrane in a water-repellent material or covered with a water-repellent material, which do not allow drops of liquid to pass through, fall within the scope of the present invention.
• the membrane is not necessarily impermeable to liquid: for example, if it is subjected to a high liquid pressure (sending a jet of liquid against the membrane for example), it can become permeable and allow the liquid to pass through.
• the membrane is impermeable to drops of liquid, to allow only pure liquid vapor to pass through the space between the condenser and the membrane, and not to allow unpurified liquid to pass through this space.
• the device may comprise a plurality of the above elements, as described with reference to Figure 1. It is thus possible to increase the exchange surface in a modular manner by adding as many channels and nozzles as are necessary to achieve the heat and mass exchanges.
• first space and the second space may also be called “channels”, or “fluidic channels”.
• channel or “fluidic channel” it is meant an element or a set of elements capable of allowing a circulation of a fluid in the gas phase or a flow or circulation of a fluid in the liquid phase.
• a fluidic channel is capable of transporting a vapor of a fluid in the gas phase and/or of collecting drops of a liquid by trickling along said channel.
• a fluidic channel may in particular be of a thickness less than or much less than its length and its width, when it is produced by mounting two membranes or two walls similar to canvases mounted on frames parallel to each other and spaced apart by the thickness of the channel, in the manner of the frames or shelves of a beehive, a seal is also obtained between the frames, by elements connecting the frames together, depending on the thickness of the channel.
• the nozzle may be a spray nozzle.
• the fluid is sprayed by the spray nozzle in fine droplets, in particular in a direction parallel to the membrane.
• the fine droplets promote the evaporation of the liquid, while limiting the pressure on the membrane.
• the nozzle may be a jet nozzle.
• the fluid is sprayed by the jet spray nozzle, particularly in a direction parallel to the membrane.
• the nozzle may be a hollow rod (or cane) (or pipe) pierced with small holes along its length through which the liquid is dispensed in the form of drops.
• the membrane comprises a first face facing the first space and a second face facing the second space, and the membrane is configured to operate at equal pressure on its first face and on its second face.
• said pressure may be atmospheric pressure.
• the membrane and the condenser wall extend in substantially vertical planes.
• the membrane and the wall of the condenser are planar (it is noted that undulations on the surface of the membrane are possible, as are patterns on the wall of the condenser).
• substantially vertical it is understood that the membrane and the wall of the condenser can each form with the ground an angle of between 70° and 110°.
• the device further comprises a first fluid distributor for supplying the nozzle with said fluid in liquid phase and a second fluid distributor for supplying the refrigerant circulation circuit with the refrigerant.
• the first distributor also called “hot liquid distributor” or “hot water distributor” hereinafter
• the second distributor also called “cold liquid/refrigerant distributor” or “cold water distributor” hereinafter
• these two distributors can be connected (possibly via other elements) so that the same fluid can be both the fluid distributed in the form of drops and the refrigerant fluid.
• the device comprises a collector configured to collect at least a portion of the fluid dispensed in the form of drops by the nozzle and circulating in the second space.
• This collector also called a “hot liquid collector” or “hot water collector” hereinafter, advantageously makes it possible to recover the portion of the fluid distributed in the form of drops by the nozzle that has not passed through the membrane in the form of vapor.
• This recovery can have several uses.
• the fluid thus collected can be thrown out of the device when it becomes too “impure” (for example too loaded with salts).
• the collected fluid can also be reused as a refrigerant liquid after cooling, as detailed below. It is noted that the liquid collected by the hot liquid collector is less hot than the liquid at the nozzle outlet, because this liquid is cooled by evaporation during its passage through the second space.
• the refrigerant circulation circuit, the nozzle and the second space belong to the same fluid circuit.
• fluid circuit is meant a circuit for circulating a fluid or, in other words, a circuit allowing a fluid exchange between the elements.
• the fluid circulating in the second space may then circulate in the refrigerant circulation circuit (possibly after passing through other elements of the device, for example a cooling system) and/or the fluid circulating in the refrigerant circulation circuit can then be distributed into the second space by the nozzle.
• the fluid circuit may be a “closed fluid circuit” (or “circuit looped on itself from a fluidic point of view”), that is to say a fluid circuit in which at least part of the fluid at the outlet of the circuit is reinjected into an inlet of the circuit.
• the term “closed circuit” does not exclude the possibility that the circuit comprises means for supplying and/or withdrawing fluid.
• part of the fluid circulating in the closed circuit may be withdrawn (for example liquid highly loaded with salts) and/or fluid coming from outside the circuit (for example liquid less loaded with salts) may be added to the closed circuit.
• the fluid circulating in the second space can be reinjected into the refrigerant circulation circuit at the outlet of which it can be evacuated.
• the fluid circulating in the refrigerant circulation circuit can then be distributed in the second space by the nozzle, and the remaining part of the liquid in the second space can then be evacuated.
• the refrigerant circulation circuit may comprise an inlet and an outlet, and the device may further comprise a first connection circuit between the outlet of the refrigerant circulation circuit and the first fluid distributor.
• connection circuit between two entities is meant an element or a set of elements allowing a fluid to flow from one of the entities to the other entity.
• a connection circuit may comprise for example one or more pipes, as well as one or more intermediate systems, an intermediate system comprising for example an inlet through which the fluid can enter the system, a circulation circuit in which the fluid circulates and a outlet through which the fluid leaves the system and an outlet into which the fluid can enter - such a system may be for example a fluid heating or cooling system.
• the first connection circuit may comprise a heating system configured to heat a fluid circulating in said first connection circuit, a connection pipe connecting the outlet of the refrigerant circulation circuit to said heating system and a connection pipe connecting said heating system to the first fluid distributor.
• Such a heating system advantageously makes it possible to heat a fluid leaving the circulation circuit of the condenser to a first temperature, and the fluid thus heated can supply the nozzle.
• the collector can be connected to the second fluid distributor.
• the fluid collected in the collector can be reinjected into the second fluid distributor, to be used as refrigerant liquid in the circulation circuit of the condenser.
• the collector may be connected to the second fluid distributor by a second connection circuit, the second connection circuit comprising a cooling system configured to cool a fluid circulating in said second connection circuit, a connection pipe connecting the cooling system to the inlet of the refrigerant circulation circuit and a connection pipe connecting said cooling system to the collector.
• Such a cooling system advantageously makes it possible to cool the part of the unpurified fluid distributed in the form of drops by the nozzle and which has not passed through the membrane in the form of vapor, to use it as a refrigerant liquid.
• the refrigerant circulation circuit and the second space belong to the same closed fluid circuit.
• the refrigerant circulation circuit and the second space belong to two independent fluid circuits. [0052] In other words, according to these embodiments, there is no exchange of fluid between the second space and the refrigerant circulation circuit. It is thus not necessarily the same fluid which circulates in the condenser and which is distributed by the nozzle.
• the device may further comprise a gutter for collecting condensate formed on the wall of the condenser.
• the gutter is meant any element allowing the collection of the condensate (here, purified liquid) formed on the wall of the condenser.
• the gutter can be a channel attached to the wall of the condenser (as in the example shown in Figure 1) and having a certain slope to convey the condensate to a collector of purified liquid.
• the gutter can also be one or more raised patterns on the wall of the condenser having the same function as the previous example.
• the gutter allows on the one hand to recover the condensate (the purified liquid), and on the other hand to prevent the condensate from coming into contact with the collector, which contains the part of the fluid distributed by the nozzle that has not evaporated and has not passed through the membrane (and which is therefore a fluid even less pure than that distributed by the nozzle).
• the gutter allows to collect the condensate without it having come into contact with unpurified fluid, and to convey it into a circuit or into a purified water tank.
• Another aspect of the invention relates to a method for purifying a fluid in liquid phase using a device described above, comprising: dispensing, through the nozzle, the fluid in the form of drops, the fluid dispensed in the form of drops being at a first temperature; supplying the circulation circuit of the condenser with the refrigerant fluid at a second temperature, the second temperature being strictly lower than the first temperature; and collecting purified fluid in liquid phase resulting from condensation of a purified fluid in gas phase along the wall of the condenser, said purified fluid in gas phase resulting from passage of a gaseous portion of the fluid dispensed in the form of drops through the membrane.
• the fluid dispensed in the form of drops is water loaded with salts, and in which the purified fluid in the liquid phase is pure water.
• the fluid is dispensed in the form of drops by the nozzle in a first direction, and in which the refrigerant fluid circulates in the circulation circuit of the condenser in a second direction opposite to the first direction.
• the refrigerant fluid and the fluid distributed in the form of drops by the nozzle circulate in opposite directions, which makes it possible to increase the efficiency of heat exchanges.
• the method further comprises: collecting a portion of the fluid dispensed in the form of drops by the nozzle and flowing in an area delimited by the membrane and comprising the nozzle; cooling said portion of the collected fluid to the second temperature;
• the cooled portion of the fluid is used to supply, at least partially, the circulation circuit of the condenser.
• the remaining portion of the unpurified liquid distributed in the form of drops which has not passed through the membrane in the form of vapor is recovered to be cooled and reinjected as refrigerant liquid.
• the method may comprise: heating the refrigerant fluid at the outlet of the condenser circulation circuit to the first temperature;
• the heated refrigerant fluid is used, at least partially, as fluid to be dispensed in the form of drops through the nozzle.
• the refrigerant liquid after passing through the condenser, is heated to supply the nozzle.
• Figure 1 shows an example device for purifying a fluid in liquid phase, according to one embodiment of the invention.
• Figure 1 represents an example device for purifying a fluid in liquid phase, according to an embodiment of the invention.
• the device of Figure 1 comprises a plurality of semi-permeable membranes 5, i.e. permeable to the fluid in the gas phase, but impermeable to the fluid in the liquid phase. More precisely, the membranes 5 are impermeable to the fluid in the liquid phase, when the latter is, for example, projected against the membranes 5 in the form of drops, the aim being that, in the context of the invention, only gaseous particles of the liquid can pass through the membranes 5.
• the device also comprises a plurality of condensers (or cold traps) 9.
• condenser is meant a device configured to condense (or liquefy) vapor.
• each condenser can be a flat condenser comprising two walls 9a, 9b between which is a circuit for circulating a refrigerant fluid.
• the walls 9a, 9b of the condenser 9 are advantageously impermeable to fluids (in both the liquid and gas phases).
• the membranes 5 do not allow drops of liquid distributed by the nozzles 3 to pass through.
• the membranes 5 may be impermeable to drops of liquid.
• the membranes 5 may be, for example, membranes made of one or more of the following materials: Teflon or PTFE, Polyvinyl Diene Fluoride or PVDF, Polypropylene or PP and Polyethylene or PE.
• the thickness of the pores of the membranes 5 may be determined by routine testing by a person skilled in the art, and in particular pore sizes ranging from 60 micrometers to 60 nanometers may be used.
• the membranes 5 may be composed of a fabric coated with a treatment to make it waterproof.
• the material used to make a wall of a condenser or a cold trap may be a metal or a heat-conducting material.
• Stainless steel, for example, or a plastic, may be used, especially if the cold liquid circulating in the condenser is salty or corrosive water.
• pairs of membranes 5 and condensers 9 are arranged alternately, such that exactly two membranes 5 are arranged between two condensers 9.
• Two membranes 5 arranged between two consecutive condensers 9 delimit a space 4 overlooked by a nozzle 3 configured to distribute a fluid in liquid phase in the form of drops or droplets.
• This space constitutes a “first fluidic channel” 4 in which the fluid distributed by the nozzle 3 circulates.
• fluidic channel it is meant a volume in which a fluid can flow or circulate, in liquid or gas phase.
• a fluidic channel can advantageously be delimited by two separators (for example membranes 5 and/or condenser walls 9), which makes it possible to maximize the heat exchange surfaces or the exchanges of matter, as for the passage of steam.
• the space 13 between a condenser 9 and the membrane 3 closest to the condenser 9 is called the “second fluid channel” 13.
• Each second fluid channel 13 may comprise a gutter 11 or any other means of recovering a liquid formed by condensation on the condenser 9.
• the gutter 11 may be connected to a collector of purified or pure water 12.
• the channel 4 and the condenser 9 are separated by a small tank or gutter 11 for collecting drops of water in liquid water from the surface of the wall 9a, 9b of the condenser 9.
• the first channel 4, the nozzle 3, the gutter 1 1 and the condenser 9 form a periodic pattern repeated in Figure 1, between a hot water distributor 2 and a hot water collector 6 connected via the channel 4 containing the nozzle 3 and between a cold water distributor 8 and a cold water collector 10 connected via the condenser 9.
• the invention can be implemented when the device comprises a nozzle 3, a membrane 5 and a condenser 9, the membrane 5 being located between the nozzle 3 and the condenser 9.
• the invention is not limited to a plurality of nozzles 3, condensers 9 and membranes 5.
• the volume of purified liquid collected is greater, since purified liquid can be collected in parallel in several channels each bordered by a membrane 5 and a wall 9a, 9b of the condenser 9, for example via several gutters such as the gutter 11.
• Figure 1 thus shows a hot water supply 1 connected, in the fluidic direction, via a hot water distributor 2 to the nozzle 3 arranged internally to the membrane of the channel 4 as well as a hot water collector 6 extending the channel 4.
• Figure 1 also shows a cold water supply 7 connected to the condenser 9 via a cold water distributor 8 which is connected, in the fluidic sense, to a cold water collector 10 via the condenser 9.
• the membranes 5 and the walls 9a, 9b of the condensers 9 are vertical and parallel surfaces. It is understood that the degree of parallelism of these elements may, without departing from the teaching of the present application, be imperfect. In particular, it is especially important that a fluid in the vapor phase can reach a wall of the condenser 9 via the channel 4.
• the verticality of the membranes 5 and the walls 9a, 9b of the condensers 9 are therefore to be understood in the present application as a characteristic making it possible to maximize the conversion of vapor into liquid, between the interior of the membrane of the first channel 4 and the surface of the wall 9a, 9b of the condenser 9, while facilitating the collection of condensates by the gutter and minimizing the size of the entire device.
• the “vertical” characteristic in the geometric sense, can be understood within the meaning of the present invention and in all its embodiments as forming an angle for example between 70° and 110° relative to the ground.
• an unpurified hot liquid (the liquid may be a mixture, for example, of water and minerals or water and salt or solutes) is introduced by a feed 1, then distributed by a hot liquid distributor 2 to nozzles 3 which disperse it vertically in the form of drops inside the channels 4.
• the unpurified hot liquid may be water from a water reserve, for example a sea or a lake or a wastewater reserve, possibly heated to a first temperature called "hot".
• a second liquid, called refrigerant liquid, which is colder than the hot liquid, is introduced by a supply 7, then distributed by a cold liquid distributor 8 which distributes it in the condensers 9 arranged in parallel in Figure 1.
• hot liquid is meant a liquid having a higher temperature than the maximum temperature of the refrigerant circulating in the condenser 9.
• the difference between the temperature of the hot liquid (when it is distributed in the form of drops by the nozzles 3) and the maximum temperature of the refrigerant circulating in the condenser 9 may be greater than 30°C.
• the hot liquid may be distributed in the form of drops at a temperature between 60°C and 90°C, and the refrigerant may have a temperature between 10°C and 30°C.
• the above temperatures are provided as examples and other temperatures or temperature differences may be used.
• the unpurified and hot liquid circulates in the channel 4 delimited by two membranes 5, and a portion of this unpurified and hot liquid passes, in the form of purified fluid vapor, through the membranes 5.
• the unpurified and hot liquid is salt water
• a portion of this liquid passes in the form of pure water vapor and passes through the membranes 5.
• the role of the membranes 5 or of the membrane 5 is to prevent the liquid distributed in the form of drops in the channel 4 from passing partially or totally into the zone 13 delimited by a condenser 9 and a membrane 5. Only vapor of the liquid can pass through, thus avoiding any contact between the hot liquid present in the channel 4 and the condensates of the vapor formed in the zone 13 on the wall of the condenser 9.
• a temperature difference is created between the two sides of the membrane 5
• a difference in partial vapor pressure appears, constituting the engine of the process. This causes the evaporation of liquid from the surface of the liquid on the hot side, generating vapor that passes through the membrane 5 and condenses on the colder side where the condenser 9 is located.
• the space between a condenser 9 and a membrane 5 forms a channel 13 in which the vapor of the hot liquid coming from the nozzle 3 and having passed through the membrane 5 diffuses.
• the role of the condensers 9 is to condense this vapor on one of its walls 9a, 9b to form purified liquid.
• This purified liquid is colder than the vapor from which it comes, while conversely, the refrigerant liquid heats up on contact - via the wall 9a, 9b of the condenser 9 - with the hotter vapor.
• the refrigerant liquid can be collected at the outlet of the circulation circuit of the condenser 9 in a cold liquid collector 10, at a temperature higher than that which it had at the inlet of the circulation circuit of the condenser 9.
• the condensate (purified water for example) slides along the wall of the condenser 9 and can be collected in the gutter 11 placed for example on the wall (several gutters in the direction of the height of the condenser 9 can also be provided). The condensate can then be transported laterally to be collected in a pure water tank or collector 12.
• the gutter or gutters 11 can either be attached to the condensers by mechanically fixing the material making up this gutter or these gutters, or delimited by the external shape of the condenser(s) by molding, i.e. delimited by the wall of a condenser, i.e. by the shape of its external surface on which the condensation is obtained.
• the elements of the device are arranged in the following order, in a direction parallel to the membranes 5 and oriented from the cold water collector 10 and the refrigerant liquid distributor 8: the cold water collector 10, the hot water distributor 2, the hot water collector 6 and the refrigerant distributor 8.
• Such an arrangement allows circulation of the liquids in the channel 4 and the refrigerant circulation circuit in the condenser 9 in the opposite direction or counter-current.
• Such counter-current circulation advantageously allows a particularly efficient exchange of heat between the hot drops produced by the nozzle 3 and the cold liquid via the membrane 5 and the wall 9a, 9b of the condenser 9.
• the elements of the device can be arranged in the following order, in the direction parallel to the membranes 5 and oriented from the cold water collector 10 and the refrigerant distributor 8: the cold water collector 10, the hot water collector 6, the hot water distributor 2 and the refrigerant distributor 8.
• the circulation of the liquids in the channel 4 and the refrigerant circulation circuit in the condenser 9 is carried out in the same direction, and the invention is still functional, even if the heat exchanges are less efficient than in the embodiments where the circulation of the liquids is done in the opposite direction.
• the invention can be implemented by means of a supply 1 of hot water or hot fluid at a first temperature, distributed in the form of drops by a nozzle 3 and creating a vapor of the (purified) fluid and drops of the fluid (even less pure than the hot fluid distributed by the nozzle 3), the vapor of the fluid passing through the membrane 5 permeable to vapor and impermeable to drops, to reach a wall 9a, 9b impermeable to the fluid, the wall 9a, 9b being supplied with a refrigerant fluid via a cold water supply 7, the refrigerant fluid being injected between the walls of the condenser 9 at a second temperature lower than the first temperature.
• a condensation of the fluid occurs in drops of purified water on a surface of the wall 9a, 9b, in contact with which flows cold water or a purified cold fluid at a temperature lower than the first temperature.
• the hot and cold supplies are possible.
• the hot fluid and the cold fluid are not reused and are both lost: there is then an open-circuit hot fluid supply and an open-circuit cold fluid supply, independent of the hot fluid supply.
• the portion of the hot liquid that has not evaporated portion of the liquid that arrives at the bottom of the channel 4, which is less hot and saltier than the liquid distributed in the form of drops by the nozzle 3 is purged out of the device, for example evacuated to a wastewater circuit.
• a new refrigerant is injected into the condenser 9 via the cold water supply 7 and a new hot liquid supplies the nozzle 3 via the hot liquid distributor 2.
• the hot fluid is reused to be purified again.
• the portion of the hot and salty liquid dispensed in the form of drops by the nozzle 3 that has not passed through the membrane 5 in the form of vapor is collected at the bottom of the channel 4.
• the liquid collector 6 can be connected to the inlet of the heating system, for example via a connecting pipe, and the heating system can be connected at its outlet to the hot liquid distributor 2, for example via a connecting pipe.
• the hot fluid supply is said to be in a "closed circuit", even if this term does not exclude that additional liquid can be injected into the circuit via the hot water supply 1 .
• the remaining liquid is highly salty, which requires it to be discarded after a certain number of cycles.
• the hot liquid distributor 2 is advantageously connected, via the heating system, to a source of unpurified liquid, to regularly dilute the hot liquid distributed in the form of drops by the nozzles 3.
• the refrigerant fluid can be discarded as in the first embodiment, or reused as in the third embodiment described below.
• the hot fluid and refrigerant fluid supplies are independent.
• the refrigerant fluid leaving the condenser 9 is reinjected into an inlet thereof.
• the cold liquid collector 10 is connected to the cold liquid distributor 8 so that the refrigerant fluid leaving the condenser 9 and arriving in the cold liquid collector 10 is reinjected into the inlet of the condenser 9 via the cold liquid distributor 8.
• the refrigerant fluid flows from the inlet of the condenser (connected to the cold liquid distributor 8) to the outlet of the condenser 9 (to reach the cold liquid collector 10), it heats up due to the contact between the hot liquid vapor and the wall 9a, 9b of the condenser.
• the refrigerant fluid at the outlet of the condenser 9 is advantageously cooled in a cooling system before being reinjected into the condenser 9.
• the cold liquid collector 10 can be connected, via a connection pipe, to an inlet of the cooling system, and an outlet of the cooling system can be connected, via another connection pipe, to the cold liquid distributor.
• the refrigerant fluid supply is in a “closed circuit” (and it is not necessary to provide a supply of additional refrigerant fluid, since the latter does not undergo a priori any transformation or loss).
• the hot fluid can be discarded as in the first embodiment, or reused as in the second embodiment.
• the supplies of hot fluid and refrigerant fluid are always independent.
• the hot fluid and refrigerant fluid supplies are not independent: the remaining portion of the hot liquid is cooled to the second temperature to be used as a refrigerant liquid, then reheated at the outlet of the condenser 9 to the first temperature to be distributed in the form of drops by the nozzles 3, and so on. It is noted that at the outlet of the condenser 9, the refrigerant liquid has warmed up, which reduces the amount of energy to be provided to bring it to the first temperature. Also, at the outlet of the channel 4, the remaining portion of hot fluid has cooled down, which also reduces the amount of energy to be provided to bring it to the second temperature.
• this fourth embodiment it is possible for example to attach the collector of hot liquid 6 to the inlet of the cooling system and to connect the outlet of the cooling system to the cold liquid distributor 8 to feed the condenser 9.
• the cold liquid collector 10 can be connected to the inlet of the heating system, and the outlet of the heating system can be connected to the hot liquid distributor 2 to be distributed in the form of drops by the nozzles 3.
• the term "closed circuit” does not exclude that additional liquid can be injected into the fluid circulation circuit.
• the remaining liquid may be highly salty, and it is possible to reinject, regularly or when it is detected that the concentration of salts in the circulating liquid exceeds a threshold value, less salty liquid (for example sea water) into the fluid circulation circuit.
• less salty liquid for example sea water
• the cooling system and/or the heating system may comprise an inlet for receiving less salty liquid.
• the less salty liquid may be added upstream of the cooling system or the heating system.
• the liquid circulation circuit may advantageously be connected to a source of unpurified liquid, to regularly dilute the circulating liquid and supply both the condensers 9 and the nozzles 3.
• This fourth embodiment makes it possible to improve the thermodynamic efficiency of the liquid purification process: in fact, a latent heat exchange takes place between the vapor of the fluid used and the drops of this fluid distributed in the form of recycled drops in undivided liquid phase, in contact with the wall. This characteristic improves condensation and simultaneously heats the recycled liquid by reducing the power required to heat this liquid to the distribution temperature by the nozzle 3. A saving of 50% in heating power can thus be observed compared to the other embodiments, this figure being able to vary depending on the sizing.
• the device comprises an initial hot water supply, distributed in the form of drops by a nozzle and separated by a membrane permeable to water vapor, impermeable to water drops distributed in the form of drops and non-absorbent for water, from a fluid-impermeable condenser, in contact with cold water on one side and on the other side with the water vapor collected after condensation, in drops of purified water resulting from the condensation of the water vapor transported between the nozzle and the condenser via the membrane.
• the purified liquid can be collected by means of one or more gutters placed on the surface of the condenser.
• the heating system may comprise, for example, an electrical resistor or may be a system for placing the fluid in thermal contact with a hot source, i.e. at a higher temperature than the fluid.
• the heating system may use waste heat from an industrial process.
• the cooling system may be a system for placing the fluid in thermal contact with a cold source, i.e. at a lower temperature than the fluid.
• a compression of a liquid can be carried out after a distribution in the form of drops by nozzle by collecting or gathering the liquid in “divided” form (i.e. in the form of drops) present at the outlet of the channel 4 to make it return to a “non-divided” liquid form.
• divided >> ie in the form of a collected liquid and not in the form of drops
• a sizing of the characteristics of the device according to one embodiment, to obtain a purified water condensate of 30 tonnes per day in an installation using sea water, is detailed below as an example.
• a reserve of cold, salty seawater, for example taken from an ocean, can be used as a cold source and as a means of dilution, as well as a source of heat, for example obtained by solar heating or by recovering energy lost in an engine.
• Cold, salty seawater can be introduced into a closed fluid circuit and circulated by means of a pump.
• the seawater can, in this closed fluid circuit, be preheated by the condensation of the water vapor by passing through the condenser 9, in a direction opposite to that of the hot drops (counter-current configuration), then reheated by the heat source by means of a first exchanger with separate fluids. It can then pass through a nozzle immersed in an atmosphere, then be distributed in the form of drops (for example, sprayed) in the atmosphere by losing water vapor, to be collected, in concentrated salt form, in a tank.
• the water concentrated in salt can be pumped from the tank, then cooled by the reserve of cold seawater in a second exchanger with separate fluids, and finally be diluted by water from the reserve of cold seawater in a mixer.
• a membrane 5 permeable to water vapor and impermeable to liquid water can separate the nozzle 3 and the condenser 9, and make it possible to obtain condensation with separate fluids, between the liquid emitted by the nozzle 3 and the condensate.
• the condensate and the liquid circulating in the condenser 9, made of a material impermeable to fluids, are separated by the material of the condenser 9.
• the mixer makes it possible to dilute the seawater, concentrated by evaporation, with seawater from the cold water reserve.
• the seawater from the reserve here plays a first role as a material reservoir, namely a seawater reservoir with a constant salt concentration.
• the mixer can be connected to the circuit intermittently or continuously, depending on a desirable salinity range for the seawater circulating in the closed circuit.
• the seawater reserve can also be used to additionally cool the water concentrated by evaporation leaving the hot water collector, to bring it to a temperature close to that of the cold, salty seawater reserve, here playing a second role as a thermal reservoir.
• the resulting device is particularly favorable to heat recovery and condensation. Tests were conducted on such a device with two condenser and membrane heights (the condensers and membranes having the same heights): 3 m for the first test and 2 m for the second test. These dimensions make it possible to obtain a heat expenditure of 300 (first case) to 450 (second case) kWh per m 3 . These figures can be compared to a heat expenditure for a device not having this heat recovery, which is of the order of 700 kWh per m 3 of condensate. This therefore represents an energy gain of 57% in the first test and 35% in the second test.
• the flow rate of cold seawater for the additional cooling by sensible heat loss can be adjusted to obtain a temperature 3 K higher than the temperature of the cold reserve in order to obtain at the mixer outlet and at the nozzle inlet, a temperature 2.5 K higher than the temperature of the cold seawater reserve.
• the temperature of the hot source can be 58 K higher than that of the cold water reserve, in permanent purified water production mode.
• a temperature of the cold seawater reserve can in particular be for these performances 305 K and the temperature of the hot seawater reserve 363 K.
• the present application extends its teaching to a solvent containing a solute to obtain the purified (or pure) or ultra-purified (or ultra-pure) solvent.
• the membrane and the wall of the condenser must not be in mechanical contact, which guarantees optimum purity of the purified fluid.
• contact points between the membrane and the wall exist, degraded operation of the device and the method according to the invention is obtained.
• the purification of water loaded with minerals initially at 500 Micro Siemens/cm results without mechanical contact in purified water having a conductivity of less than 9 Micro Siemens/cm while the presence of contact points leads to purified water having a conductivity of the order of 50 Micro Siemens/cm.

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• Engineering & Computer Science (AREA)
• Water Supply & Treatment (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Hydrology & Water Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Organic Chemistry (AREA)
• Separation Using Semi-Permeable Membranes (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

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• 2023
  • 2023-03-24 FR FR2302821A patent/FR3146814A1/fr active Pending
• 2024
  • 2024-03-19 CN CN202480029117.4A patent/CN121152671A/zh active Pending
  • 2024-03-19 WO PCT/EP2024/057268 patent/WO2024200108A1/fr not_active Ceased
  • 2024-03-19 EP EP24711578.5A patent/EP4688231A1/de active Pending
  • 2024-03-19 KR KR1020257035579A patent/KR20260002770A/ko active Pending
  • 2024-03-19 JP JP2026501775A patent/JP2026509942A/ja active Pending

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