WO2008104900A2

WO2008104900A2 - Injectable water distillation system

Info

Publication number: WO2008104900A2
Application number: PCT/IB2008/050594
Authority: WO
Inventors: Silvio Lavagna
Original assignee: Università degli Studi di Roma 'La Sapienza'
Priority date: 2007-02-26
Filing date: 2008-02-19
Publication date: 2008-09-04
Also published as: EP2114542A2; ITRM20070105A1; WO2008104900A3

Abstract

A distillation system (1 ) and method, for the distillation by evaporation of a liquid solution and subsequent condensation thereof. The system (1) comprises a control unit, suitable for managing production processes and controlling process parameters; a tank (10) for storage of said liquid solution; means (11 ) for collecting a given flow rate of said liquid solution from said tank (10) and inletting it into a fluid-dynamic circuit of said system (1 ); a phase separation chamber (100), apt to induct said given flow rate of liquid solution until attaining a corresponding hydrostatic column H in said separation chamber (100); a heat exchanger (30), in double fluid connection (a,b), respectively liquid and gaseous, with said phase separation chamber (100), apt to carry out a preliminary evaporation of a given fluid stream of said liquid solution, returned into said exchanger (30) from said phase separation chamber (100); power-generating means, apt to cooperate with said heat exchanger (30) so as to output thereto the power required to carry out said evaporation; an unit (50) for condensing said vapour (50) and extracting the distillate deriving therefrom by distillation ducts (6); wherein said power-generating means comprises a modular electromagnetic microwave generator (200), cooperating with said control unit in the sense of adjusting the power developed proportionally to the hydrostatic head that is established in said heat exchanger (30) at the transit of said fluid stream of said liquid solution.

Description

INJECTABLE WATER DISTILLATION SYSTEM

DESCRIPTION

The present invention refers to a liquid distillation system for injectable preparations and the like; specifically, it refers to a system for the distillation of injectable water by evaporation of feed water, suitable for a preliminary production of pure vapour, and subsequent condensation of said pure vapour.

The present invention also illustrates a related liquid distillation method for injectable preparations and the like. The present invention finds application in the field of construction of systems and apparatuses for separation of complex mixtures and purification of substances, in particular in the setting up of technologies of which are typically equipped laboratories; hospital structures; and industrial systems intended for treatment of solutions such as water, with special reference to applications in the biopharmaceutical field. In the field of production of water for pharmaceutical uses, in this case, distillation represents the final purification stage to which it is subjected water that has already undergone preliminary purification treatments, such as, e.g., demineralization.

Generally, distillation systems for injectable water, ordinarily indicated by the caption "water for injection", being based on preventive evaporation for the generation of pure vapour, and on separation of the latter from a residue of non-volatile impurities, are remarkably affected by problems of low energy efficiency.

In fact, the energy amount that has to be provided for the evaporation of each unit of solution, with respect to system losses, often makes distillation apparatuses uneconomic. Thus, consumptions attributable to evaporation heavily weigh on the operating economy of all typologies of distillation systems currently in use, differentiated thereamong by the modes of delivering energy required for vaporizing the solution, e.g., thermocompression, simple or multiple effect or dropping film, their productivity being highly conditioned thereby. Moreover, in connection with the different modes of carrying out feed solution evaporation in distillation systems in use in the known art, respective drawbacks and constructive complications occur. Drawbacks most frequently found in the known art are: the low reliability in guaranteeing constant quality of pure vapour produced; a difficulty in keeping the system under pressure; a considerable inertia and difficulty in achieving the working pressure and/or performing a thermal degassing under pressure of the feed solution at the start of the distillation process; the need of a frequent maintenance of the heat exchangers; an inefficient ability to adjust the delivery of vaporization energy depending on the flow rate of distillate that is to be instantaneously produced. Heat exchangers currently in use in the distillation field use heating elements (resistors) or tube bundles in which a primary fluid flows to cede heat to a secondary fluid to be evaporated.

From such heat exchanging modes, there follows the constructive need of an energy generator kept inside the same heat exchanger, so that a mutual physical contact useful to the exchange may set in.

Generally, there arises the constructive need to have bodies immersed in the solution to be evaporated, to cede heat required for evaporation. Such a constructive solution entails design complications, and implies the drawbacks of a consistent loss of heat generated, as well as a water contamination risk.

In the current state of the art, in the reference field, there are no distillation system and method by evaporation of a liquid solution and subsequent condensation thereof capable of guaranteeing delivery of a controllable amount of highly pure distillate, with a readily adjustable production, rapidly reaching steady state operation; and concomitantly such as to ensure a high thermal efficiency thanks to an optimized mode of exchanging modulating heat.

Therefore, object of the present invention is to solve said problems, by proposing a distillation system, and a distillation method implementable by such a distillation system, as defined respectively in claim 1 and in claim 16. The distillation system according to the present invention reconciles the needs of a high thermal efficiency, and therefore of a proportional energy saving, with the needs of a high purity of the clean vapour produced and, therefore, of a superior quality of the distillate obtained from condensation of the latter. The distillation system according to the present invention is readied for production over short times from installation, rapidly reaching in each of its compartments the respective internal working pressure.

The mode of generating power required to overheat the solution to be treated, and therefore to induce evaporation thereof in the exchanger, is such as to allow a system construction in which the source of said power is advantageously kept outside the heat exchanger. The power generating mode and associated heat exchange occur so as to optimize selective achievement of the aim and minimize energy losses.

Specifically, the power generator is contrived with a modulating criterion and delivers energy (power) continuously and automatically adjusting it to the distillate flow rate required at the outlet and to the proportional amount of solution introduced by collection from the storage tank upstream of the system.

Said advantage complies with the ever more felt demand to integrate, in the equipments used, flexibility features and automatisms facilitating and making less critical an adjustment to contingent conditions of use.

In this perspective, the distillation system according to the present invention determines a regularization and an optimization of the production rates, otherwise not attainable with known systems. Constructive solutions adopted, in particular for the power generator and the associated heat exchanger, make the distillation system according to the present invention overall more compact and on average less bulky than the conventional ones, thereby requiring lower maintenance and management costs. The entailed reduction in dimensions further translates into a rationalization of the occupation of spaces in production systems.

Further advantages, as well as the features and the operation modes of the present invention will be made apparent from the following detailed description of an embodiment thereof, given by way of example and not for limitative purposes. Reference will be made to the figures of the annexed drawings, wherein: - figure 1 is a first schematization of a first embodiment of the distillation system according to the present invention, apt to illustrate the constituent apparatuses thereof and a related sequence of respective operating stages, from the inletting of a solution from a storage tank to the extraction of a distillate obtained by the condensing of a product from treatment of said liquid solution; and - figure 2 is a second schematization of a second embodiment of the distillation system according to the present invention, apt to illustrate the component apparatuses thereof and a related sequence of respective operating stages, from the inletting of a solution from a storage tank to the extraction of a distillate obtained by condensation of a product from treatment of said liquid solution. To describe the present invention, hereinafter reference will be made to the above- indicated figures.

Referring to figures 1 and 2, a distillation system 1 according to the present invention comprises a tank 10 for storage of the liquid solution to be treated to obtain the final distillate; means 11 for collecting a given flow rate of said liquid solution from the tank 10 and inletting it into a fluid-dynamic circuit of the system 1 ; a phase separation chamber 100, apt to induct said given flow rate of liquid solution; a heat exchanger 30, in double fluid connection a,b, respectively substantially liquid and gaseous, with the phase separation chamber 100, and apt to carry out a preliminary evaporation of a given fluid stream of liquid solution, returned into the exchanger 30 from the phase separation chamber 100; and an unit 50 for condensing the vapour and extracting the distillate deriving therefrom.

The ducts 4, 5, respectively making said double fluid connection a,b with the separation chamber 100, close substantially ring-like onto the separation chamber 100. The fluid flow of the liquid solution inlet, e.g. forcedly, by collecting means such as a feed pump 11, like a multistage centrifugal motor-driven pump, enters the fluid-dynamic circuit of system 1 according to the present invention and is inducted into the phase separation chamber 100 until attaining a corresponding hydrostatic column H. The fluid-dynamic circuit of the system 1 is preferably kept under controlled pressure, for a correct development of the phenomena that will be illustrated hereinafter. The fluid stream that is established in the heat exchanger 30 following the return from the separation chamber 100 is preferably proportional to the flow rate of liquid solution inlet into the separation chamber 100. The biphasic fluid produced at the stage of the heat exchanger 30, where fluid stream evaporation can typically take place being partial, passes to the separation chamber 100, where separation between liquid phase and vapour phase is completed, the vapour thus purified being preferably collected, e.g. on the substantially apical portion of the head of the phase separation chamber 100, by distillation ducts 6. The double fluid connection of the heat exchanger 30 to the separation chamber 100 is made by respective portions of fluid-dynamic circuit comprising first ducts 4 for conveying said fluid stream from the phase separation chamber 100 to the heat exchanger 30; and second ducts 5 for conveying to the phase separation chamber 100 the biphasic fluid produced in said heat exchanger 30. Conveying of the biphasic fluid produced in the heat exchanger 30 preferably occurs at a section of the phase separation chamber 100, on a level substantially higher than the hydrostatic column H that has set in.

The ducts 5 are also configured so as to cooperate with the phase separation chamber 100 in order to direct the vapour phase, which constitutes the biphasic fluid, preferably at the top of the separation chamber 100, and anyhow at the distillation ducts 6.

Preferably, a control unit presides over operations executable in the sequence of operating stages provided along the fluid-dynamic circuit of the system 1. The control unit may be programmed to act with totally automated modes, or it may interface, by a selectively operable board, with technicians in charge of actuating and/or remotely monitoring production processes and structures, so as to instantaneously allow a combined and interactive management of the distillation system 1.

It is envisaged means 7 for refining the phase separation, preferably placed substantially at the top of the phase separation chamber 100, apt to further purify vapour that is separated from the biphasic fluid being outlet from the heat exchanger 30. The distillation system 1 according to the present invention comprises power-generating means, apt to cooperate with the heat exchanger 30 so as to output thereto the power required to carry out a programmed evaporation of the fluid stream created therein. Such power-generating means in this case comprises an electromagnetic microwave generator 200, preferably having modular structure.

In particular, the modular electromagnetic microwave generator 200 may comprise a plurality of magnetrons 201 , e.g. arranged in a line. The electric component of microwaves emitted by the microwave generator 200 transfers energy suitable for heating the liquid solution inside the exchanger, wave absorption effect by the solution being substantially kinetic.

Radiative transfer to heat exchanger 30 is preferably regulated so that generator 200 develops a power proportional to the hydrostatic head that is established in the heat exchanger 30 at the transit of said fluid stream of liquid solution.

Therefore, adjustment of power developed by the electromagnetic microwave generator 200 thanks to said control unit, via, e.g., a power detector apt to send a corresponding signal to a feed control actuator, preferably occurs with a modulation proportional to the hydrostatic head that is established in the heat exchanger 30 at the transit of said fluid stream. Such a hydrostatic head is, e.g., measured by a level sensor placed in the exchanger 30, connected to the control unit so that, on the basis of data collected thereby and in comparison to those obtained from the power detector, there be set the condition of the feed control actuator.

Thus, power output by each magnetron is managed in connection to the flow rate of the fluid stream transiting in the exchanger and, in the last instance, proportionally to the distillate flow rate required at the outlet.

The microwave generator 200, thus coupled to the heat exchanger 30 inside which it is concentrated the energy emitted for fluid stream overheating, may comprise an adapter and a tuner for tuning microwave radiation to the exchanger 30 and its content. Besides said adapter and a tuner, e.g. of the type known as 3-stub tuner, the microwave generator 200 preferably comprises a power detector according to said modes, in communication with the control unit in order to evaluate energy generated and proportionally reflected, and therefore manage the magnetrons 201 in the span of the production process.

The power detector, in particular, transmits analog or digital signals, e.g. with a voltage in a range of 0÷10 Volt, processable e.g. by a PLC in the control unit apt to impart proportional commands to actuators, such as said feed control actuator.

Each magnetron 201 , remote head suitable for microwave generation, is preferably equipped with an integrated insulator for protection from reflected waves.

With regard to the specific applications of the two preferred embodiments disclosed in figures 1 and 2, the liquid solution feeding the system 1 is purified water.

The resulting distillate is injectable water, in the technical field of reference generally designated by the phrase "water for injection". Said first ducts 4 for conveying liquid solution to the heat exchanger 30 comprise a length having diverging-converging sections.

Such sections are apt to accelerate the flow of the corresponding fluid stream inlet into the heat exchanger 30, proportionally increasing the Reynolds number thereof. The configuration of first conveying ducts 4 and heat exchanger 30 is such that their cooperation makes the flow of the fluid stream turbulent, bringing the Reynolds number beyond the laminar flow threshold.

The chamber of the heat exchanger 30, for both embodiments of figures 1 and 2, is distinct from the phase separation chamber 100. Thanks to said design solution, a strong turbulent flow is established in the ducts 4, which increases the energy efficiency of the thermal exchange in the exchanger 30. Power of magnetrons 201 is transmitted to the liquid phase of the turbulent-flow fluid stream, causing a sudden and likely partial evaporation thereof.

By effect of this partial evaporation, pressure inside the heat exchanger 30 rises rapidly, up to a predetermined value, preferably kept constant by the adjustment system enslaved to the control unit in steady state condition.

Thus, a liquid-vapour biphasic flow is established in the chamber of the heat exchanger 30.

The above-introduced second conveying ducts 5 likewise comprise a length having converging-diverging sections, apt to obtain an acceleration of the fluid flow being outlet from the heat exchanger 30, essentially referring to the vapour phase resulting from evaporation that took place therein, propelled into the ducts 5 by the pressure increase that has occurred.

Mutual proportions and configurations of conveying ducts 5 and separation chamber 100 are such that the inletting of fluid flow from the heat exchanger 30 into the compartment of the phase separation chamber 100 following said acceleration occurs tangentially with respect to the ducts-separation chamber interface.

The fluid flow, still partially biphasic, enters the separation chamber 100 preferably angled with respect to the axis of ducts 5, its inletting into the substantially widened compartment of the separation chamber 100 being accompanied by a joint sudden expansion thereof.

Expansion with such a strong negative pressure gradient, a procedure known in technical jargon as "flashing", is apt to produce a further evaporation for improving the separation, within the substantially biphasic fluid flow downstream of the exchanger 30, of residual liquid particles from vapour.

The configuration of the interface between ducts 5 and separation chamber 100 is such as to induce a cyclonic advancement motion of the flow entering the separation chamber 100. By virtue of the centrifugal force generated in association with the cyclonic advancement motion, a further separation of the vapour and liquid phases occurs.

In fact, subjected to said force, liquid particles coalesce impinging onto the walls of the separation chamber 100, until merging at the bottom thereof, where liquid solution inducted from the tank is held, collecting thereat as condensate.

The synergistic effect of the sudden expansion, or biphasic flash, in conjunction with the cyclonic tangential motion, ensures a deep and clear-cut separation between condensed liquid droplets and the vapour phase that is preferably conveyed at the top of the separation chamber 100.

Moreover, a boosted expansion procedure thus carried out fosters a preventive separation and segregation of the particles of incondensable gases such as CO₂, N₂, and O₂, which can be finally removed in the subsequent storage phase. It is also provided means 7 for refining the phase separation, preferably placed substantially at the top of the phase separation chamber 100, apt to further purify the vapour phase, in order to attain a high grade of the pure vapour produced.

Such means 7 for refining the phase separation is, e.g., mechanical traps, apt to foster coalescence of any liquid dragging and therefore prevent gaseous phase contamination. Thus, it is attained the production of pure, sterile vapour, free from any suspended particle and/or metal ions, as well as apyrogenic, in compliance with European and U.S. pharmacopoeiae (EU-Ph. 5 and USP 29 ).

In particular, following analyses performed online on pure vapour produced with the distillation system 1 according to the present invention in order to trace any contamination by total organic Carbon, a parameter commonly designated by the acronym TOC, monitored values proved to be systematically below the allowed limit of 0.5 ppm.

Electric conductivity of the distillate at a 25 ⁰C temperature is of 1.3μS/cm.

Moreover, it was found by offline analyses that endotoxin value keeps below the value of 0.25

EU/ml. A suitable measuring and sensor instrumentation, duly installed along the fluid-dynamic circuit inside the distillation system 1 according to the present invention, allows to automatically keep under control the crucial operating parameters of the system, such as temperature, pressure, flow rate, flow speed, conductivity.

The instrumentation suitable for controlling process parameters presides, among other things, over: control and holding of pure vapour pressure, control and holding of feed liquid solution level in the storage tank 10; control and holding of level of liquid solution inducted into the separation chamber 100; control of the velocity of fluid inlet to the heat exchanger 30, e.g. by a flow rate transmitter; control of temperature and pressure inside the heat exchanger

30; control and adjustment of power output by the microwave generator 200, depending on consumption and liquid head set in the heat exchanger 30.

Temperature of outlet distillate, in this case water for injectable applications, preferably ranges between 85°C < T < 95⁰C. For a good strength and a lengthened life cycle, portions of equipment of the distillation system 1 into contact with fluid during the production process are made, e.g., of AISI TP

316L stainless steel, preferably with surfaces exhibiting average roughness Ra≤O.6, pickled and passivated. Thermal insulation may be made of polished AISI 304 stainless steel sheet.

The storage tank for feed water is preferably of vertical type; portions thereof into contact with fluid during the production process may be made of AISI TP 316L stainless steel, and it has surfaces with a roughness Ra≤0.6, pickled and passivated.

Welding for the assembly of the apparatuses of the system according to the present invention may be performed under a protected inert gas atmosphere and, specifically referring to the above-described biomedical applications, the componentry is of sanitary type.

The support structure may be of AISI 304 stainless steel, preferably glazed.

An electric control and command board for the circuit distributing electric power to the system may be made of AISI 304 stainless steel, preferably glazed. The distillation system 1 according to the present invention may have two distinct embodiments, according to the assembling configuration of the heat exchanger 30 relative to the phase separation chamber 100.

According to a first embodiment, schematized in figure 1 , the heat exchanger 30 is assembled in a configuration substantially perpendicular to the phase separation chamber 100.

According to a second embodiment, schematized in Figure 2, the heat exchanger 30 is instead assembled in a configuration substantially parallel with respect to the phase separation chamber 100.

In keeping with the respective constructive variants, there will be adapted the ducts for induction of said flow rate of liquid solution into the phase separation chamber 100 and the ducts 4 for returning and collecting said liquid solution to the heat exchanger 30.

Object of the present application is also a distillation method for the distillation by evaporation of a liquid solution and subsequent condensation thereof.

Such a method comprises the steps of collecting a given flow rate of a liquid solution from a storage tank 10, inletting it, preferably forcedly, into a fluid-dynamic circuit of the distillation system 1 ; then, delivering such a flow rate of liquid solution into a phase separation chamber

100, preferably until attaining a corresponding hydrostatic column H in the separation chamber; delivering a proportional fluid stream of liquid solution in a heat exchanger 30 having double fluid connection a,b, respectively substantially liquid and gaseous, with the phase separation chamber 100; performing a generation of electromagnetic microwaves 200 modulated so as to output to the heat exchanger 30, by radiative transfer, a power proportional to the hydrostatic head that is established in the heat exchanger 30 at the transit of said fluid stream of said liquid solution; and then carrying out a preliminary partial evaporation of the fluid stream, returned into the exchanger 30 from the phase separation chamber 100.

The distillation method according to the present invention may further provide the step of preliminarily accelerating the fluid flow being outlet from the heat exchanger 30, and of inletting then said fluid flow into the compartment of the phase separation chamber 100, following the acceleration imparted, tangentially with respect to the interface between ducts 5 and separation chamber 100.

Thus, as illustrated above, the flow is angled with respect to the axis of the fluid connection ducts 5.

Accordingly, it is generated a cyclonic advancement motion of the fluid flow inside the separation chamber 100, thereby obtaining, by virtue of the centrifugal force developing, a further separation of the vapour and liquid phases.

The step of carrying out a preliminary evaporation inside the heat exchanger 30 can be associated to a subsequent step of suddenly expanding the fluid flow concomitantly to its inletting into the compartment of the phase separation chamber 100, so as to produce a further evaporation for improving the separation, within the fluid flow still partially biphasic at the entering into the compartment, of residual liquid particles from vapour.

Such a step of suddenly expanding is referred to as flashing. The distillation method according to the present invention may further comprise the step of generating a turbulent motion within the fluid stream of liquid solution, concomitantly to the step of delivering into the heat exchanger 30.

Turbulent motion of the fluid stream fosters heat exchange, facilitating overheating and evaporation. Downstream of the fluid-dynamic circuit of the system 1, the production process concludes with the step of condensing the vapour phase of the fluid flow, collecting said phase at the top of the phase separation chamber 100, and of extracting its distillate for storage.

The radiative transfer associated to microwave emission attains a nearly instantaneous localized overheating of the fluid. Hence, reactions fostered by such an energy transfer mode are quicker and take place with efficiency and yield greater than with heating via traditional methods.

The option of controlling operative and process parameters, which can be traced back to the microwave generator 200 ability to modulate power output depending on contingent needs, guarantees a high degree of reproducibility of the procedures for production of pure vapour and injectable water.

By virtue of the heating of the liquid solution carried out via a microwave generator 200, advantageously a "thermal flywheel" is triggered, keeping under thermal agitation the particles of the solution even when the microwave generator 200 is in a stand-by condition. This "thermal flywheel" mechanism allows yet a remarkable power saving. Generated microwaves selectively act on the fluid only, and not on the exchanger body, machine efficiency being thereby enhanced. The compact structure and easy assembly of the distillation system 1 according to the present invention advantageously entail lower maintenance costs with respect to the known systems, suffering from constructive complications.

The present invention has hereto been described according to a preferred embodiment thereof, given by way of example and not for limitative purposes. To the above-described distillation system 1 and related distillation method a person skilled in the art, in order to satisfy further and contingent needs, could effect several further modifications and variants, all however encompassed by the protective scope of the present invention, as defined by the annexed claims.

Claims

1. A distillation system (1) for the distillation by evaporation of a liquid solution and subsequent condensation thereof, comprising: a control unit, suitable for managing production processes and controlling process parameters; a tank (10) for storage of said liquid solution; means (11) for collecting a given flow rate of said liquid solution from said tank (10) and inletting it into a fluid-dynamic circuit of said system (1); a phase separation chamber (100), apt to induct said given flow rate of liquid solution; a heat exchanger (30), in double fluid connection (a,b) with said phase separation chamber (100), apt to carry out a preliminary evaporation of a given fluid stream of said liquid solution, returned into said exchanger (30) from said phase separation chamber (100); power-generating means, apt to cooperate with said heat exchanger (30) so as to output thereto the power required to carry out said evaporation; wherein said power-generating means comprises a modular electromagnetic microwave generator (200), cooperating with said control unit in the sense of adjusting the power developed proportionally to the hydrostatic head that is established in said heat exchanger (30) at the transit of said fluid stream of said liquid solution.

2. The distillation system (1) according to claim 1, wherein said liquid solution is purified feed water and said distillate is injectable water.

3. The distillation system (1) according to claim 1 or 2, further comprising means (7) for refining said phase separation, apt to further purify said vapour.

4. The distillation system (1) according to claim 3, wherein said means (7) for refining said phase separation is mechanical traps, placed substantially at the top of said phase separation chamber (100).

5. The distillation system (1) according to one of the claims 1 to 4, wherein said control unit cooperates with said modular electromagnetic microwave generator (200), in the sense of adjusting the power thereby developed proportionally to the hydrostatic head that is established in said heat exchanger (30) at the transit of said fluid stream and, in the last ' instance, proportionally to the distillate flow rate required at the outlet.

6. The distillation system (1) according to one of the claims 1 to 5, wherein said modular electromagnetic microwave generator (200) comprises a plurality of magnetrons.

7. The distillation system (1) according to claim 6, wherein said magnetron are arranged in a line.

8. The distillation system (1) according to one of the claims 1 to 7, wherein said double fluid connection (a,b) is respectively substantially liquid and gaseous and respectively comprises:

• first ducts (4) for conveying said fluid stream from said phase separation chamber (100) to said heat exchanger (30); and

• second ducts (5) for conveying to said phase separation chamber (100) a fluid flow produced in said heat exchanger (30) and/or for directing said fluid flow at the top of said separation chamber (100);

9. The distillation system (1) according to one of the claims 1 to 8, wherein said first conveying ducts (4) comprise a length having diverging-converging sections apt to accelerate the flow of said fluid stream inlet into said heat exchanger (30), proportionally increasing the Reynolds number thereof.

10. The distillation system (1) according to claim 9, wherein the configuration of said first conveying ducts (4) and said heat exchanger (30) is such that their cooperation makes said flow of said fluid stream turbulent, bringing the Reynolds number beyond the laminar flow threshold.

11. The distillation system (1) according to one of the claims 1 to 10, wherein said second conveying ducts (5) comprise a length having converging-diverging sections apt to obtain an acceleration of the fluid flow being outlet from said heat exchanger (30), the mutual proportions and configurations of said conveying ducts (5) and of said separation chamber (100) being such that the inletting of said fluid flow from said heat exchanger (30) into the compartment of said phase separation chamber (100) following said acceleration occurs tangentially with respect to the interface between ducts (5) and separation chamber (100).

12. The distillation system (1) according to claim 11, wherein said preliminary evaporation in said heat exchanger (30) is partial and the mutual proportions and configurations of said conveying ducts (5) and of said separation chamber (100) are such that the inletting of said fluid flow into the compartment of said phase separation chamber (100) is accompanied by a joint sudden expansion thereof, apt to produce a further evaporation for improving the separation, within said partially biphasic fluid flow, of residual liquid particles from vapour.

13. The distillation system (1) according to claim 11 or 12, wherein said interface between the conveying ducts (5) and the separation chamber (100) is configured so as to generate a cyclonic advancement motion of the flow entering the separation chamber (100), apt to obtain, by virtue of a consequent centrifugal force, a further separation of the vapour and liquid phases.

14. The distillation system (1) according to one of the claims 1 to 13, wherein said heat exchanger (30) is assembled in a configuration substantially perpendicular to said phase separation chamber (100).

15. The distillation system (1) according to one of the claims 1 to 13, wherein the heat exchanger (30) is assembled in a configuration substantially parallel with respect to said phase separation chamber (100).

16. A distillation method for the distillation by evaporation of a liquid solution and subsequent condensation thereof, comprising the steps of: collecting a given flow rate of a liquid solution from a storage tank (10), inletting it into a fluid-dynamic circuit of a distillation system (1 ); delivering said flow rate of liquid solution into a phase separation chamber (100), until attaining a corresponding hydrostatic column (H) in said separation chamber; delivering a proportional fluid stream of said liquid solution into a heat exchanger (30) having double fluid connection (a,b), respectively substantially liquid and gaseous, with said phase separation chamber (100); performing a generation of electromagnetic microwaves (200) modulated so as to output to said heat exchanger (30), by radiative transfer, a power proportional to the hydrostatic head that is established in said heat exchanger (30) at the inletting of said fluid stream of said liquid solution; and - carrying out a preliminary evaporation of said fluid stream, returned into said exchanger (30) from said phase separation chamber (100).

17. The distillation method according to claim 16, further comprising the step of accelerating said fluid flow being outlet from said heat exchanger (30), and of inletting then said fluid flow into the compartment of said phase separation chamber (100) following said acceleration, tangentially with respect to the interface between conveying ducts (5) and said phase separation chamber (100) of said fluid flow and said separation chamber (100), so that the flow be angled with respect to the axis of said ducts (5).

18. The distillation method according to claim 16 or 17, wherein said step of carrying out a preliminary evaporation is associated to a step of suddenly expanding said fluid flow concomitantly to its inletting into said compartment of said phase separation chamber (100), so as to produce a further evaporation for improving the separation, within said partially biphasic fluid flow, of residual liquid particles from vapour.

19. The distillation method according to one of the claims 16 to 18, comprising the step of giving to the fluid flow inlet into the compartment of said phase separation chamber (100) a cyclonic advancement motion of said fluid flow, obtaining, by virtue of a consequent centrifugal force acting on said fluid flow, a further mutual separation of the vapour and liquid phases.

20. The distillation method according to one of the claims 16 to 19, comprising the step of generating a turbulent motion within said fluid stream of said liquid solution, concomitantly to the step of delivering into said heat exchanger (30).

21. The distillation method according to one of the claims 16 to 20, comprising the step of condensing the vapour phase of said fluid flow, collecting said phase at the top of said phase separation chamber (100), and of extracting its distillate.