FR3101682A1 - Helical siphon compressor: desalination, CO2 extraction, dehumidification, liquid aeration, heat engine, compression-decompression, decompression-compression - Google Patents

Abstract

Helical siphon compressor: desalination, CO2 extraction, dehumidification, liquid aeration, heat engine, compression-decompression, decompression-compression. An Archimedean screw under the surface of a liquid translates downwards and compresses the pockets of gas that its virtual bells trap. It can drive a reverse pitch screw to combine compression and decompression. The quasi-isothermal desalination of salt water by reverse Hirn cycle at 23.14 hPa, the dehumidification of the air by decompression beyond the dew point, the extraction of carbon dioxide from a gas by liquefaction at 5.7291 MPa, alcoholic distillation at room temperature, oxygenation of rivers under the effect of the current, the transformation of thermal energy into mechanical energy are examples of applications. The low friction, the absence of any valve, stuffing box or other movable sealing part are notable. Figure for abstract: fig. 9

Description

Helical siphon compressor: desalination, CO2 extraction, dehumidification, liquid aeration, heat engine, compression-decompression

The present invention generally relates to a device for pressurizing, depressurizing or pressurizing and depressurizing in the two orders of succession of a gas or a liquid. The helical siphon compressor combines on the one hand the principle of the screw or propeller (similar to the Archimedes screw) to transform a rotational movement into translation on the other hand that of the siphon to constrain pockets of gas enclosed in the virtual siphons that form the locally upper parts of the propeller to undergo the pressure gradient of the liquid in which it is immersed. It combines the qualities of the volumetric compressor (flow independent of the load) and those of the turbine compressor (reduction of friction and absence of valve for the continuity of the supply). At the cost of size, with friction reduced to viscosity forces and with perfect sealing, the helical siphon compressor can be mechanically associated with a decompressor to impose fruitful pressurization-depressurization cycles at low cost. To provide significant pressure differences without excessive bulk, the helical siphon compressor can segment the screw into several suitably pressurized sub-screws.

The compression of the gaseous phase of salt water previously decompressed to its saturation pressure (23.14 hPa at 20°C) makes it possible to condense this naturally desalinated vapor at ambient temperature. Variants allow freeze-drying or alcoholic distillation at room temperature, i.e. without thermal attack on the aromas.

The compression of a gas containing carbon dioxide up to its liquefaction pressure (5.7291 MPa at 20°C, approximately 56 times atmospheric pressure) makes it possible to extract this carbon dioxide, the expansion of the remaining gas reducing largely the energy cost of the operation.

Heating a compressed gas before decompressing it makes it possible to recover mechanical energy from thermal sources that are too mediocre to use other operating methods.

The decompression of humid air makes it possible to dry it beyond the dew point by foehn effect, the compression of the remainder largely offsetting the energy cost of the operation.

Rivers suffer from chronic oxygen deficits: the helical siphon compressor makes it possible to remedy this under the sole action of their current.

State of the prior art

The Archimedes screw belongs to the public domain. The version revisited by Leonardo da Vinci replaces the fixed casing against which the auger rubs with a rotating casing, eliminating the friction caused by sealing requirements: the venerable concrete mixer is an application as commonplace as it is proven.

There are a few recent patent filings using Archimedes screws, they do not include any of the claims of this application:

• Hydroelectric power station with Archimedean screw rotor EP2796707 - 2014-10-29
• Apparatus for generating hydroelectric power WO20100821292010-07-22
• Set WO2011128640 - 2011-10-20
• Ship propulsion using an endless screw FR2895367 - 2007-06-29 (BOPI 2007-26 )

These Archimedean screw use cases apply to liquids, whereas the present invention compresses or depressurizes gases.

Today, the desalination of salt water uses either osmosis units requiring compressions of the order of 10 MPa, lost in the osmotic membrane which must be periodically regenerated by reverse sweeps, or boilers which heat up to boiling at reduced pressures and then cooling the liquid, with the inherent thermodynamic losses. The system proposed here lowers the boiling temperature to room temperature to avoid the need for cooling and reduce these thermodynamic losses; one of the other advantages is to produce dry residues that can be used for other purposes, without generating and diluting brine that is harmful to the environment. Lyophilization conventionally uses very low pressure after freezing, distillation at boiling at atmospheric pressure, two operations that are detrimental to the protection of aromas. Inspired by Pascalization, hypobaric sterilization deserves to be finally evaluated.

No device for extracting carbon dioxide by compression until it liquefies seems to have been proposed, probably because of the energy cost of such compression if effective decompression is not associated.

Due to its zero buoyancy, the rotor of the compressor-decompressor is subject to very low mechanical resistance due to the forces of viscosity while offering a perfect seal. This asset is used to exploit weak thermal resources and transform them into mechanical energy.

Professor Wong from the University of Akron (USA/Ohio) could extract 39 liters of water per hour from a desert atmosphere thanks to the nano-fibers of a hydrophilic polymer (744 mg of water captured per centimeter square and per hour). To meet this need for dehumidification, no way involving the decompression of air beyond the dew point and then its compression has been identified.

Many systems exist for oxygenating rivers, none using a rotor as simple as that of the present invention.

The staircase of the Château de Chambord designed by Leonardo da Vinci combines two helical surfaces in the same direction; here several helical surfaces of the same direction are effectively associated, with other helical surfaces of opposite directions.

The Marly machine supplied the Palace of Versailles with water by drawing water and energy from the Seine and segmenting the pumping into three stages; the present invention achieves the same result without any valves.

Introductory note on compression by helical siphons

Figure 1 describes a simple helix (curve winding around a cylinder, intercepting its generatrices at a constant angle) of radius r and pitch p (x=rsinθ, y=r cosθ z=pθ) whose axis is inclined at an angle β with respect to the vertical. When this angle β exceeds the constant angle between the generatrices of the cylinder and the propeller, a constant angle determined by the pitch p, this propeller has local extrema which are exploited by the compressor.

Combining the three-dimensional curve of the propeller with a liquid retention pipe makes it possible to develop a precursor of a helical siphon compressor whose helical parts between the points (1) and (2) correspond to the angles θ ₁ and θ ₂ or θ ₁ +2π and θ ₂ +2π constitute virtual troughs capable of retaining a liquid. All it takes is one rotation, whatever its speed, for these virtual troughs to translate and move the liquid they contain; these troughs are virtual insofar as several physical parts of the helical pipe associated with the propeller will constitute them in turn.

The front view and the calculation show that the center of gravity of the liquid present in the trough is laterally offset with respect to the axis and generates a moment tending to rotate the helical siphon compressor precursor in the direction of descent of the liquid. Either the rotation of this compressor precursor will drive to cause the liquid to rise, or the descent of the liquid will drive to cause the said compressor precursor to rotate.

This liquid translation system is interesting for its simple and efficient feeding and spilling: just put the center of the base of the helical siphon compressor precursor on the diopter of a liquid surface (3) and collect this liquid just as it comes out in a gutter. We can notice the absence of friction between moving and fixed parts to ensure their tightness, the absence of a valve, the absence of minimum speed, the minimum difference in level for evacuation in a gutter and the great reversibility.

It is calculated that for β=45° and p=0.5 r, approximately half the length of each turn is between a “pass” (1) of θ ₁ =30° and the following point (2) at the same altitude (θ ₂ =218°) and that this combination fairly well optimizes the compromise between size, flow rate and torque. For the low compression under a high flow of figures 10 to 12, the couple β=10° and p=3.1 r will be proposed. The term “siphon” is justified by the projection in “U” of the helical pipe making it possible to isolate by a liquid two volumes of gas.

Figure 2 corresponds to the immersion of this precursor of helical siphon compressor in a liquid limited by the diopter (3), now constituting a real helical siphon compressor. The term "siphon" is retained for the ability of the liquid portion of the pipe to provide separation between two distinct gas volumes by the "U" projection of this helical pipe which the pressure gradient makes more accurately resemble a "J ". The descent of a gas and its compression are obtained by the positioning of the helical siphons of figure 1 in the pressure gradient of the liquid. The gas is introduced by the upper part, called the suction part, the diopter (3) cutting for the reasons of filling the upper base of the cylinder by its half. Gas filling corresponds more exactly to the absence of liquid above the interface (3) in accordance with the principle of communicating vessels. Below this diopter, gas is trapped in the upper portions of the siphons and descends as the screw compressor rotates; it is now the upper parts of the siphons which constitute virtual bells in translation in which the gases are housed between two volumes of liquid occupying the remaining volume. The term bell in the case of a gas replaces that of trough in the case of a liquid by referring to plunger bells. Placed end to end, the cumulative heights of the intermediate columns of liquid correspond exactly to the total height.

The rotation of the helical siphon compressor will cause a translation of the gas pockets in the pressure gradient of the liquid towards an area where the hydrostatic pressure of the liquid will be different, thus modifying that of the gas by the value P=hρg, P being the pressure , h the depth or altitude variation of said gas pocket, ρ the density of the liquid used and g the gravitational constant. The question of the reduction of the gaseous volume under the effect of its compression and the untimely displacement of the intermediate columns of liquid will be resolved later.

On balance, the helical siphon compressor has a suction part above a gas-liquid interface (3) and a compression part below; the rotation of this compressor traps the gas above the diopter in the virtual bells formed by the helical siphons; this rotation also determines their depth within the pressure gradient of the liquid column below said interface (3) and compresses the gas trapped in said virtual bells.

If we look at Bernoulli's formula + + gz applied on the one hand to the pocket of gas, on the other hand to the pocket of liquid replacing it, one can consider that the kinetic energies of the gas and of the liquid as constants and say that by conservation of the enthalpy, the helical siphon compressor transforms the quantity gz corresponding to the displacement of the liquid pocket which compensates that of the gas pocket by modifying the pressure of this gas pocket , to within the potential energy variation of the gas pocket.

Figure 3 shows how the pipe associated with the propeller can be improved to increase the volume used. Inside a cylinder of radius R ₁ , helicoidal surfaces of pitch p between radii R ₀ and R ₁ are inserted:

• Length determined by k, positive real number defining the number of periods
• 0 ≤ θ ≤ 2 k π, 0 ≤ n ≤ 7 for 8 helical surfaces
• Point (4): x = R ₀ sin (θ + n π / 4), y = R ₀ cos (θ + n π / 4), z = R ₁ θ /2
• Point (5): x = R ₁ sin (θ + n π / 4), y = R ₁ cos (θ + n π / 4), z = R ₁ θ /2

This evolution allows:

• the transformation of the circular section of the pipe associated with the helix by a section limited by two helical surfaces,
• the extension of the useful section to the whole of the cylinder on which the propeller rests, by cutting off the central channel,
• the installation of a central channel of radius R ₀ in communication with the outside of the cylinder in which the liquid can move according to the variations in level of the virtual bells under the effect of the pressure.

Several helical surfaces are nested to increase the volume used, eight in the example of figure 3 but, with β = 45° and p = 0.5, the modeling shows that one can insert up to twelve helical surfaces without interference . This assembly constituting a rotor makes it possible to arrange the virtual bells in translation in accordance with FIGS. 3 and 5, determined firstly by a cylindrical wall (5) of radius R ₁ , secondly by a central cylindrical channel (4) of radius R ₀ , thirdly by a helical wall between the central channel (4) and the cylindrical wall (5) to which it is welded to seal the virtual bells, fourthly by a horizontal surface inside a level line (7) resting on the upper point (7') of the intersection between the central channel and the helical wall and lastly by the inclination β of the cylinder (5) and of the central channel (4) by relative to the horizontal. The bells in translation are distributed by the gas-liquid interface (3) between suction bells and compression bells. The upper point (7') of the intersection between the central channel and the helical wall defines a level line (7), the base of the bell in translation, which will isolate and enclose the pocket of gas when it meets the diopter (3). Above the diopter (3), the suction bells are full of gas, a rotation of the compressor translates them downwards until the level line (7) reaches the diopter (3) and isolates the pockets gas they contain. Below the diopter (3), said pockets of gas isolated by the bells in translation undergo the pressure gradient of the column of liquid under the diopter (3) via the surface inside the line of level (7) and are compressed accordingly. Their compression reduces the volume of the gas pocket, its lower surface rests on a level line which is no longer in contact with the central channel as illustrated in 7'', according to the principle of communicating vessels the central channel has allowed to replace the volume of compressed gas with liquid.

The low value of R ₀ directly increases the volume of the bell. The disadvantage of the displacement of the intermediate columns in the case of the example of FIG. 2, at the origin of the untimely displacement of bubbles from one gas pocket to the other, disappears; with the central channel, the pockets of gas are at the moment of meeting with the interface (3) at the limit of overflowing into the central channel by the point (7 '), then gradually restricted to the upper part of the bells by the increase in pressure: the central channel supplies the liquid necessary to compensate for this reduction in volume. This channel is also important to overcome the position of the interface (3) relative to the ends (6) of the compressor. The examples of Figures 1 and 2 were optimized with an interface (3) in the center of the disc, and imperatively between the ends (6) of this disc; with the central channel, the height at which the diopter intersects the helical siphon compressor is in this respect of no consequence. The positioning of the diopter (3) is therefore not limited between the ends (6) of the base of the cylinder but can descend indifferently below (6) while guaranteeing nominal suction.

The object rotor of FIG. 3 is designed to possess zero buoyancy when all the bells in translation are nominally filled with gas so that the frictions are reduced to those which the viscosity generates. For this purpose, some parts will receive adequate ballast blocks.

Figure 4 comes back to the case of the rise of a liquid and shows the vertical translation of the virtual trough as the rotation of the helical siphon progresses until the spill in (11). The trough being difficult to define in space, it is only a question here of the horizontal projections of the external part of the lower of the two helical surfaces enclosing the virtual trough. The generators (8) and (9) associated with the edges of the virtual trough show that the tightness of the trough is well ensured, despite the central channel not shown. The proven concrete mixer example would answer any doubts. The volume of the trough will be optimized with generatrices which will not be exactly perpendicular to the axis (10), a later study will make it possible to determine the value of this variation.

The other merit of this figure is to show how, whatever the speed of rotation, the level curve formed by the edges of the virtual trough will pierce the interface (3) and raise its contents to force it to undergo the translation.

Figure 5 corresponds to the helical siphon compressor immersed in a liquid under the interface. At the top of the compressor, the virtual bell above the diopter descends gradually to pierce it with the level line (7), the liquid closes the gas pocket captured and behaves like a particularly reliable seal, perfectly sealed and rigorously indestructible. The pocket of gas is thus enclosed between the upper part of the virtual bell up to the point (7') of the central channel on which the surface rests inside the level line (7), regardless of a times the speed of rotation, then translated until it escapes at (11). It can be noted that as the rotating part of the compressor is entirely immersed in the pressure gradient of the liquid under the interface, it is not subject to any pressure differential and can be made of light materials such as polyethylene for example.

A secondary effect of the descent of the gas pockets is the entrainment of the liquid in the same direction under the effect of the helical walls with a slip that is all the lower as the speed of rotation is high.

The helical siphon compressor thus behaves like a virtual bell, lowering a pocket of gas in a liquid gradient, with the advantages of simpler entrainment, filling and emptying.

To obtain the pressure of 5.7291 MPa necessary for the liquefaction of carbon dioxide at 20°C, the density of 2.5 of the envisaged barite fluid will require a drop of 230 m, which can be divided into 16 sub-compressors of about fifteen meters.

Figure 6 indicates for this purpose how several stages of pressurization of a liquid can be associated in progressively pressurized modules compared to the previous one of the overpressure hρg. A motor (12) drives the rotor (13) of a module which will raise virtual troughs of liquid. The potential energy of the rise of the liquid is transformed into hydrostatic energy by the drop column and the progressive pressurization of the cells ensures the stability of the levels. This rotor (13) drives a transmission shaft (14) which passes through a liquid column. Said liquid column fulfills for the shaft (14) an ideal stuffing box function, absolutely sealed and only subject to the friction of the shaft-liquid viscosity. The shaft is not the only conceivable means of transmission of the movement, a connecting rod, a belt, a chain, for example, would be just as suitable, with the same irreproachable tightness insofar as they cross the liquid column in which the pressure gradient is located. The movement is imparted to the following rotor to be transmitted step by step to the other rotors which operate at higher pressures.

Figure 7 adapts the segmentation of figure 6 to the compression of a gas. Each stage provides an overpressure of hρg. Each manifold connecting two stages is pressurized to the final compression pressure of the stage upstream of the overpressure hρg so that its compression liquid does not invade this manifold. This is the resumption of the principle of the "bird trough" whose depression at the top of the tank retains the liquid up to the neck of the trough part. A baffle (15) conforms to the cylinder surface of the helical siphon sub-compressor so that the compressed gases are channeled to the manifold where the transmission shaft (14) driving the next stage is located. In regular operation, each collector receiving as much gas from the upstream stage as it loses by suction from the sub-compressor of the following stage, the pressures and the levels of the diopters remain constant. The segmentation into progressively pressurized sub-compressors thus makes it possible to reduce the overall size of the device and to transmit the drive movements without any sealing device comparable to a valve seal, a piston ring or a stuffing box. .

To reduce the energy cost of compressing a gas, the major part of which is then decompressed, two layers of helical surfaces of opposite directions are joined together as shown in FIGS. 8 and 9 in order to simultaneously allow the compression and the decompression of two gas flow.

This combination of helical surfaces is defined below:

Length determined by k, positive real number defining the number of periods

0 ≤ θ ≤ 2 k π, 0 ≤ n ≤ 7 for 8 internal helical surfaces, 0 ≤ m ≤ 11 for 12 external helical surfaces

Point (4): x = R ₀ sin (θ + n π / 4), y = R ₀ cos (θ + n π / 4), z = R ₁ θ /2

Point (5): x = R ₁ sin (θ + n π / 4), y = R ₁ cos (θ + n π / 4), z = R ₁ θ /2

Point (16): x = R ₁ sin (-θ + m π / 6), y = R ₁ cos (-θ + m π / 6), z = R ₁ θ /2

Point (17): x = R ₂ sin (-θ + m π / 6), y = R ₂ cos (-θ + m π / 6), z = R ₁ θ /2

The external helical surface thus has at (17) an external diameter R ₂ . In the example drawn, 12 external helical surfaces are nested. The mechanical solidarity between the two assemblies of helical surfaces is ensured at (16) by a welding of the helical surfaces on the internal cylinder, while maintaining an equal pressure of the liquid by a system of small scuppers. This is the exact resumption of the function of the central channel of radius R ₀ of FIG. 3. The scuppers are represented at (16) by an absence of a line; their edges joining the internal rotor and the external crown would however justify solid lines which have been deliberately omitted to facilitate the clarity of the diagram.

Figure 9 shows two of the virtual bells of these opposing helical surface assemblies. Their projections on the front view unsurprisingly show the antagonistic moments they generate and therefore the recoverable work. This is the heart of the invention; a comparable configuration would correspond to two bells positioned on either side of an axis like the two arms of a Roberval balance in which two gaseous volumes would have been introduced, this configuration would offer the same reversibility, but would be much less convenient to on the one hand to move to great heights and on the other hand to fill or empty. For the clarity of the drawings, the scuppers are not shown.

It will be seen later and in FIGS. 18 to 21 how two gas flows can supply these assemblies of helical surfaces of opposite directions without coming into mutual contact.

Introductory note on thermal braces

The helical siphon compressor aims to achieve physical state changes: vaporization and condensation. If the temperature and the pressure constitute essential conditions for such changes of state, it is necessary to register these changes of state in the duration, that is to say to bring the energy flows necessary so that the pressure and temperature conditions remain unchanged. The implementation examples below often combine opposing energy flows: heating then cooling, or vice versa. The concept of a thermal bridge is based on bringing flows at different temperatures together while separating them by a thermally conductive partition: here it is easier to move a physical flow than to set up a system for moving heat, for example by radiators and intermediate heat transfer fluid.

Note preliminary on the a decompression beyond the dew point

The passage of a mountain barrier generates the lift of an air mass containing water vapour, both pushed by the wind. The mixing ratio of water vapor in air is often less than 10 g of water vapor per kilogram of air. Upstream of this barrier, the air parcels undergo an expansion which cools them, typically 10°C per 1000 m up to the base of the clouds: we speak of dry adiabatic because no change in the state of the water vapor does not yet come into play. Depending on the dew temperature, at a determined level of pressure and therefore of altitude, the water vapor constituting a very small part of these plots begins to condense in the form liquid, that is to say in the form of a cloud and generally causes precipitation. The humidity level is said to have reached 100%. As the rising wind maintains the ascent, the water vapor continues to condense and the heat emitted by this change of state reduces the cooling corresponding to the sole expansion of the air: we speak of wet adiabatic or pseudo-adiabatic with global cooling reduced to typically 6°C per 1000 m. At the level of the summit, the condensation is no longer maintained by the lift and the air mass dried by the precipitation (new dew point and new mixing ratio) descends along the downstream slope in a pseudo-adiabatic compression until at its condensation altitude (cloud base). The condensation altitude of this slope is significantly higher than that of the upstream slope because of the precipitation and therefore the reduction in the mixing ratio. Compression below this altitude no longer uses liquid water, so it is truly adiabatic at 10°C/1000 m. The difference between the two dry adiabats corresponds to the heating and the reduction of the humidity of the air mass after the passage of the relief. The emagram graphs account for the phenomenon, illustrated in figure 24.

Description of b isothermal oiler

To carry out a quasi-isothermal distillation at room temperature, the two branches of an inverted "U" tube are immersed in two tanks of Figure 10, (20) for salt water and (21) for water. desalinated. The device (22) keeps the level of the tank (20) constant by supplying it with degassed salt water, the production of which will be described later. The device (23) performs the overflow function of the reservoir (21) to evacuate the desalinated water produced and to maintain the level of this reservoir (21) constant.

The height h ₀ corresponds to the pressure of 23.14 hPa at 20° C. at which the degassed salt water from the tank (20) can evaporate (about ten meters), it reaches the level (24). To prevent the desalinated liquid from the other inverted “U” branch from evaporating at this same pressure, a layer of edible oil is used to protect said desalinated liquid. Its density of typically 0.9 allows the desalinated water column above which it is located to have a significant hydrostatic pressure while avoiding any risk of evaporation thanks to the saturated vapor pressure of the cooking oil. typically 13 Pa, more than a hundred times less. Of course, the lower density of this edible oil will cause its level (25) to be slightly above the level (24).

The branches of the inverted "U" are therefore unevenly filled with liquid because of the use in one of said branches of a layer of liquid (edible oil) with a density slightly lower than that of salt water in the other branch , but at the saturation vapor pressure much lower than that of said salt water, said layer of edible oil preventing the evaporation of the desalinated water above which it is located. So that the levels (24) and (25) are fixed whatever the atmospheric pressure and the temperature of the environment, the levels of the reservoirs (20) and (21) will be adaptable by adjusting the angle α of the devices regulation (22) and (23). If the operating range is specified between 970 hPa and 1060 hPa, the salt water temperature between 3°C and 25°C (saturation vapor pressures of 8 hPa and 32 hPa respectively), the height h ₀ to be obtained must be between 93800/ρg and 105200/ρg, ie a variation of approximately 1.20 m for the regulating devices (22) and (23) of the reservoirs (20) and (21) respectively.

The virtual bells of an auxiliary helical siphon compressor (26) take gas from the upper part of the inverted "U" and lower the pressure on demand when it is above 23.14 hPa. At the start of the operation of the auxiliary compressor, the gases filling its virtual bells are composed on the one hand of water vapor and on the other of undesirable gases resulting from the degassing of the salt water. As they descend towards the tank (20) which will increase their pressure, the water vapor will condense into vapors which will mix with the salt water; for their part, the undesirable gases will only compress on the way down. On arrival in the lower part of the auxiliary compressor and in the tank (20), three kinds of residual gaseous particles will be released inside this tank (20): gases other than water vapor whose extraction completes the degassing of the upper part of the inverted "U" and which will rise to the surface of the tank (20), the desalinated water vapors which will mix with the salt water without rising to the surface, the steam from water whose low heat exchange did not allow condensation, which will be lost by crossing the surface of the tank (20). The pressure reduction in the upper part of the inverted "U" will be compensated by the liquids of the tanks (20) and (21), thus sucked up to the levels (24) and (25).

The device (22) ensures the supply of salt water to the tank (20); when the system is started by switching on the auxiliary helical siphon compressor (26), a device, not shown, does the same to fill the tank (21) with desalinated water. During this start-up operation, the shut-off (40) will be opened to purge the condenser part of the heat exchanger (34) in order to eliminate the quantity of gases other than the water vapor which would remain there. To reduce water vapor losses in the salt water tank (20), the operation of the auxiliary compressor (26) will be limited to the start-up periods, to the periods during which the insufficient degassing of the salt water will make it necessary to reduce the pressure in the upper part of the inverted "U" and the periods of reassembly of the enclosures (33) after cleaning the crystals to restore a satisfactory pressure therein. These efficiency-damaging losses could have been avoided by venting the auxiliary compressor (26) into the desalinated water tank (21); such a solution was rejected because it would have led to the potential deposit in this tank of traces of polluting outgassing gases which evaporate at more than 23.14 hPa, thus reducing its purity. This auxiliary compressor (26) is driven by a mechanical transmission system opening above the reservoir (20) and by a motor, not shown.

If the degassing of the salt water proves to be too detrimental to the proper functioning of the isothermal boiler, an auxiliary degassing system described below and FIG. 13 will make it possible to replace the salt water supply of the tank (20) by a supply of specifically degassed salt water.

A pump (27) is used to inject the desired amount of edible oil into the desalinated branch of the inverted "U" tube containing the power siphon compressor (32) described later, or to inject air if the emptying of this branch of the inverted "U" tube is desired, for example for a maintenance operation. A second identical pump (27bis) will inject air into the other branch of salt water comprising the auxiliary helical siphon compressor (26) to empty it.

A helical siphon compressor (28) is used in the salt water leg in its "liquid lift" or "pump" version to lift salt water into (30) for gravity feed into (30a) l evaporator-condenser (29). This pump (28) is driven by a shaft running through the full length of the "salt water" leg of the inverted "U" tube, comparable to the auxiliary compressor drive shaft (26) already mentioned. The drippings from the evaporator-condenser (29) and the centrifuge (39) are recovered at (31) and recycled at (31 bis) slightly lower. The two collectors (30) - (30 bis) and (31) - (31 bis) filled with salt water will constitute "U" not inverted and not represented, their base being in the tank (20) where a sectioning will be installed. During regular dismantling of the enclosure (33) for removal of solid deposits, the sealing of these two sections will not be critical to avoid the loss of depression of the upper part of the inverted "U": the column of salt water above them protects the low pressure of the upper part of the inverted "U". A small amount of salt water from the pump (28) will vaporize: if the pressure indeed allows this change of state, the lack of caloric intake will hinder the process; this weak evaporation will however not be detrimental because it will end up in the evaporator-condenser (29) described below.

These two collectors (30) - (30 bis) and (31) - (31 bis) constitute a thermal link arranged between the two branches of the inverted "U" tube to provide the considerable caloric intake necessary for evaporation (2453, 55kJ/kg). This significant caloric intake comes from the condenser part, which generates an almost identical quantity of heat. The evaporator and the condenser are therefore grouped together in the same heat exchanger (34) in which the salt water to be evaporated and the steam to be condensed are only separated by a thin transfer partition for the latent heat of condensation and evaporation. , thin partition preferably made of copper to increase the thermal flux. This partition and the associated pipes correspond to the thermal ramp already mentioned. The pressure difference on either side of said partition is very low (a typical value of 168 Pa will be found later).

The evaporator-condenser (29) consists of a removable enclosure (33) in which the heat exchanger (34) is located, a simple copper tube closed at its end which only has to withstand the low overpressure of the compressor power (32). The top of this heat exchanger (34) is sprayed with salt water from (30) and (30 bis), which trickles down to its base while evaporating. The runoff on the external part of the heat exchanger (34) is necessary in order not to risk putting particles of salt in suspension in the gaseous part, which spraying would certainly do. Under the effect of the low pressure and the heat from the condenser part inside the heat exchanger (34), the salt water evaporates by streaming so that its vapor is extracted in (35) where it is sucked by the power compressor (32) via on the one hand the sectioning (38) opened during the commissioning of this evaporator-condenser (29), on the other hand via the upper part of the "U" tube reversed and finally via the centrifuge (39). At these pressure and temperature, the evaporation rate is determined by the heat rate of the heat exchanger (34), which itself draws its heat from the condenser constituting its internal part. The heat exchanger (34) therefore constitutes a thermal link which brings together the flow of salt water (30 bis) to be evaporated and the flow of water vapor from the upper part of the inverted "U" tube to be condensed, while keeping them separated by a thin partition to optimize heat exchange (2453.55kJ/kg).

Inside the heat exchanger (34), at its pressure and temperature, the condensation flow corresponds to the heat flow absorbed by the evaporator in the external part. The copper composition and the low thickness of the heat exchanger (34) promote this heat flow. As the thermal conductivity of liquid water is considerably lower than that of copper, the layer of water (41) flowing in the lower part of the condenser acts as a thermal screen. To prevent this screen from generating less evaporation on the other side, the heat exchanger has in the lower part and inside radiating plates (42), compensating for the heat screen of the condensed water vapour.

These radiating plates (42) inside the heat exchanger (34) allow the heat flow between the inside and the outside of said exchanger to bypass the screen constituted by the condensed water in its lower part (41) and therefore to optimize said thermal flow. They are shown in Figure 10 in the evaporator-condenser section (29). With this configuration, the masking of the metal parts by the runoff of condensing water is minimized. The heat flow at the location of the runoff of condensation water (41) no longer crossing the heat exchanger but along it to the upper end of the radiator plates (42), the thickness of the heat exchanger will be increased at this point. Runoff inside the heat exchanger (34) and along the radiator plates (42) will descend to the collector (37) where it will meet the edible oil layer at level (25). It will continue to flow between the walls and the layer of oil present which will fulfill a valve function.

The salts crystallize on the outer shell of the heat exchanger (34), mostly at its lower part; the enclosure (33) of the evaporator-condenser (29) is periodically disassembled to remove these crystals which degrade the heat exchanges. If the pump (28) has too high a flow rate, drippings of brine fall into (31) then into (31 bis) where they are recycled with the incoming salt water. The heat exchanger is subject to a 45° inclination here, but a different slope may be chosen to optimize runoff evaporation. The heat flux is determined by the area of the evaporator-condenser. Although the external cylindrical shape is one of the least optimal with a constant size, it has nevertheless been chosen to facilitate the regular cleaning of the salts which will crystallize there. Several condenser evaporators (29) can be mounted in parallel on the inverted "U" tube, the enclosures (33) of which are each dismantled in turn as the crystallization progresses, which degrades the heat exchanges and therefore increases the associated drippings. Their sections (38) first isolate the interior of the enclosure from the upper part of the inverted "U" tube.

The upper part of the inverted "U" tube feeds water vapor at 23.14 hPa to a centrifuge (39) which eliminates potentially salty vapors, recycled via (31) and (31bis) with the drippings. It is conceivable to install an ultra-violet source of power there to sterilize the organisms carried by the water vapor which would have succeeded in reaching this point and would have survived the low pressure. Depending on the desired degree of desalination, the centrifuge can be omitted.

The dried water vapor from the centrifuge (or in its absence from the upper part of the inverted "U" tube) feeds a helical siphon compressor called a power compressor (32) which compresses this vapor very slightly but with a large flow of water to force it through the "compression" phase of an inverted Hirn cycle. If in a classic boiler the majority of the power is used for heating, here the majority of the power is dedicated to the compression which drives the reverse Hirn cycle. The low temperature difference (typically 5.1°C) testifies to the low energy consumption of this reverse cycle. The parameters β = 10° and p = 3.1r in Figures 11 and 12 might be suitable. The description of one embodiment below provides the orders of magnitude used: compression for injection 1.86 cm below level (25), gas temperature increase of 5.1°C.

Figure 12 shows how 12 helical surfaces (360°/30°) can draw in and discharge water vapor without interfering. This figure represents one of the twelve siphons, made up of the two helicoidal surfaces that delimit it, one in a solid line and the other in dotted lines to differentiate them, according to a 360° cycle. The right part corresponds to a magnifying glass between 160° and 190°. At 0° the siphon emerges from the gas-liquid interface (25) and gradually fills with the gas it sucks up to 180°. After 180°, the two left parts of the helical surfaces are in the compression part under the diopter, the rotation of this compressor has trapped the gas above the diopter of the virtual bells which the helical siphons form; this rotation also determines their depth within the pressure gradient of the liquid column below said interface (25) and compresses the gas trapped in said virtual bells up to around 270° with exhaust in the right part under a backpressure corresponding to 1 .86cm. The rotation around 180° corresponds to the closing of a virtual valve, which will complete the separation of a pocket of water vapor from the salt water from which it comes and force its descent within the layer of oil. eating ; below this layer of oil is the desalinated water tank (21) which will receive the condensates from this steam pocket. The exhaust is complete around 285°, no pocket of gas could remain in the siphon. The siphon remains under the diopter up to approximately 360°, where it emerges from the diopter to draw in fresh gas up to 180°.

This compressor is crossed by a central channel of diameter R ₀ comparable to that of FIG. 3 so that the variations in pressure and therefore in volume in the virtual bells under the effect of the pressure gradient are compensated by a transfer of said central channel which regardless of the depth at which the diopter (25) intersects the helical siphon compressor. When all the virtual bells are nominally filled with gas, the rotor immersed in the mixture of desalinated water and edible oil has zero buoyancy so that the friction is reduced to that which the viscosity generates. The rotor of the power compressor (32) is driven by a motor (19), by means of a kinematics conventionally traversing the pressure gradient up to the level of the rotor of the power compressor. So that the side effect of the helical siphon compressor, namely the entrainment of the liquid in the same direction as the gas, does not disturb the level of the free surface (25), scrolls (36) are installed which eliminate the opposition to this drive (for clarity, the direct junction between these two scrolls (36) is not shown).

Once compressed below 23.14 hPa at 20°C by approximately 168 Pa (24.82 hPa), the water vapor should have condensed inside the power compressor and descended directly to the reservoir (21 ) if the heat to be evacuated of 2453.55kJ/kg had unfortunately not marginalized this condensed proportion. The power compressor (32) injects at about 1.86 cm below the level (25), pressurized by the food oil, a gas flow which will cross a layer of oil with minimized but unavoidable energy losses, borrow the deflector (15) of the collector (37) and end up in the condenser part, therefore internal, of the heat exchanger (34) with the majority of the overpressure due to the power compressor. The deflector (15) in the upper part of the collector (37) is inclined so that the bubbles from the compressor escape to the condenser and do not return to the suction part. This collector (37), filled in its middle part with edible oil, thus allows the gaseous flow to pass in this upper part towards the heat exchanger and in its lower part towards the tank (21) the water flow. desalinated. The condensation rate is determined by the extraction of the latent heat of condensation, very slightly lower than the 2453.55kJ/kg of evaporation, the main compressor providing the energy difference necessary for evaporation. Furthermore, as condensation reduces the volume and therefore the pressure, compression towards the condenser is essential to remain above the condensation pressure of 23.14 hPa at 20°C. Compression will finally result in a rise in temperature due to its more adiabatic than isothermal character. Indeed, if the pockets of gas trapped in their bells will actually be in contact with the liquid which encloses them, the heat exchanges through these diopters will be incomplete with regard to the duration of maintenance above said diopters. The temperature increase generated by the adiabatic component of the compression adds to the latent heat of condensation to match the latent heat of evaporation on the other side of the wall of the heat exchanger (34).

System regulation takes into account the following points:

• The auxiliary compressor (26) is sporadically activated as soon as the pressure in the upper part of the inverted "U" is greater than 23.14 hPa at 20°C, i.e. at start-up, as soon as the imperfections degassing are felt and to find a correct pressure after reassembly of an enclosure (33). The power compressor is then immediately stopped to prevent a degassing bubble from penetrating inside the condenser via the manifold (37). For the same purpose, the opening of (40) will allow the interior of the heat exchanger (34) to be purged as a preventive measure.
• From a given operating speed of the power compressor (32), the pressure difference between the supply of the power compressor (32) and the interior of the heat exchanger (34) will be used to control the pump (28). Too low a pressure difference (too strong condensation) will correspond to too high a pump (28) flow rate. Too high a pressure difference will correspond to too low a pump (28) flow rate (insufficient condensation compared to the intakes of the power compressor).
• The flow of drippings at the outlet of the evaporator-condenser (29) will be observed. A higher flow reveals the degradation of the heat exchanges, that is to say the presence of an excessive deposit of salts outside the heat exchanger (34) of the evaporator-condenser (29). To this end, it is necessary to close the sections between (30) and (30 bis), (31) and (31bis) as well as (38), dismantle the enclosure (33), clean the external surface of the heat exchanger (34) of the salts which have crystallized there then carry out the reverse operations to put it back into service. The availability of several evaporator-condensers (29) in parallel will avoid disturbing the flows and interrupting production.

In the balance, the particle of the "salt water" branch of the inverted "U" tube, which has relaxed by its hydrostatic gradient up to typically 23.14 hPa at 20°C, was imposed an inverted open Hirn cycle , which will drive it into the same thermodynamic state in the "fresh water" branch of the same "U" tube:

• complete vaporization by contact with the hot wall of the heat exchanger,
• compression by the power helical siphon compressor which will slightly increase the temperature,
• cooling of the vapor in the condenser with the cold wall of the heat exchanger,
• condensation of steam in the condenser,
• cooling of the liquid in the condenser to its initial thermodynamic position.

As always with thermal machines, this is an idealized cycle where the expansions and compressions are isentropic; the reality is slightly different with expansions and compressions between isothermal and adiabatic, to the detriment of performance. Considering the weak thermal exchanges between the warm air and the sea that oceanography teaches us, we can anticipate a compression significantly closer to adiabatic than to isothermal. In this respect, the helical siphon compressor does not particularly differ from other compressors.

The isothermal boiler can be supplied with degassed salt water by means of the device of FIG. regularity of its operation. It will thus be possible to use such a degassing device.

We recognize in Figure 13 some components of Figure 10. The tank (43) provides the supply of non-degassed salt water. Valve (44) can supply supply to tank (20) on start-up, the device cannot produce until both legs of the "U" tube have been vented. Precise regulation of the level of the tank (43) is important, it alone guarantees the flow in (45) at the right pressure, slightly lower than 23.14 hPa, that is to say after some acceptable losses by evaporation.

Figure 14 shows how foodstuffs or other objects (46) can be freeze-dried or sterilized by hypobaric means around the saturation vapor pressure of commonly accepted edible oil of the order of 13 Pa: it suffices to operate the compressor long enough to evaporate and suck in all traces of moisture and compromise the vitality of living cells.

Figure 15 corresponds to an application of the helical siphon compressor for the distillation of alcohol at room temperature. The distilled alcohol is placed in a receptacle (47), a pump allows it to flow onto a plate (48). Edible oil is used to generate the pressure gradient, fresh water having a propensity to combine with alcohol into eutectic mixtures. Alcohol's saturation vapor pressure of 58 hPa higher than that of water (23.14 hPa) allows it to evaporate first. The alcohol vapors condense by compression in the bells, above the edible oil (the density of alcohol is lower than that of oil). These condensates, an eutectic mixture of water and pure alcohol, are released into the tank (21) at the surface of which they can be collected. The absence of any heating will have preserved the aromas from degradation. The plate (48) extends to the bottom of the oil column by a thermal conductor so that the heat resulting from the condensation is available for vaporization.

E carbon dioxide extractor

According to the tables, carbon dioxide liquefies at 20°C at the absolute pressure of 5.7291 MPa; its density is 773 kg/m3 (it floats on water); at this pressure, the latent heat is 152.00 kJ/kg; its critical point at 31°C constitutes the limit below which the temperature of the carbon dioxide to be liquefied must be. The helical siphon compressor is intended to compress gaseous mixtures likely to contain this carbon dioxide (discharge from industrial installations for example) to liquefy it on the condenser (55) of Figures 17 and 20, to transform the mists produced into liquid by centrifugation at (68) of FIG. 20, drawing off these liquids at (69) and expanding the gas residue in the decompression stages of the helical siphon compressor. The carbon dioxide extractor therefore uses the helical siphon compressor in compressor-decompressor version by associating two layers of helical surfaces of opposite directions as illustrated by FIGS. 8 and 9. To facilitate the manipulation of carbon dioxide, its condensates in (69) can be cooled and solidified in dry ice before being released. If the use of this carbon dioxide is not sought, for agriculture for example, it can be stored for indefinite storage in flooded mine shafts more than 600 m deep, immersion at which it remains liquid at Room temperature. The only constraint is to enclose it in heavy packaging to give the whole a negative buoyancy (carbon dioxide in the liquid state is lighter than water).

To take account of the critical point at 31°C, the helical siphon compressor-decompressor aims for isothermal compression-decompression, whereas the compressors more traditionally perform adiabatic compression. First of all, the segmentation into sub-stages of figure 16 with intermediate heat exchangers contributes to this objective. In addition, the proximity between the bells during compression and those during decompression figure 18, the mixing of the pressurization liquid and the thermal jumpers of the thin metal walls separating the collectors "x''" and "x''' ("x" taking any value between "a" and "p") promotes heat exchange. Thus, the gases leaving the decompression stages, therefore cooled, will cool the pins coming from the compression stages by being concentrically inside. These pins pass through metal plates (54) in the cooling chimney of Figure 17 to complete their cooling by the flow of fresh air A which enters from below. Said pins and metal plates heat this flow of fresh air A which will rise by convection in the chimney and thus maintain the suction of fresh air. The number and the height of the metal plates (54) are calculated so that all the calories to be exchanged are transferred by convection to the flow of the chimney. These plates allow the circuits of the condenser (55) to pass at their base. Above pass the collectors of the thermal jumpers "x"-"x'" and "x''"-"x'''" as well as the B-B' flow of the gas from which one seeks to extract the carbon dioxide. B' is connected to (50) of Figure 16 to power the system. The gas from which the carbon dioxide (53) has been extracted is reinjected into the chimney, at a point above the plates (54), not shown.

Figure 16 describes the association of all the stages of the helical siphon compressor used with a liquid of specific gravity 2.5 (mixture of barite commonly used in the oil industry and in public works). Without any particular consequence, this mixture will initially absorb carbon dioxide until it is saturated. The compression height to obtain 5.6 relative MPa is approximately 230 m. The segmentation described in figures 7 and 18 makes it possible to reduce the overall dimensions to sixteen sub-compressors of around fifteen meters in height. Their diameters decrease as the pressure rises, which will favor their mechanical construction. There is therefore segmentation into progressively pressurized sub-compressors in order to reduce the overall size of the device and to transmit the drive movements without any sealing device.

Once compressed by the first stage, the gas heated there feeds a cooling pin "a" - "a'" whose ends are marked "y" - "x'" figure 18. The same is true for each of the next fifteen stages of compression; the cooling devices are sized to remain as much as possible below the temperature of 31°C, above which no extraction of carbon dioxide by this method is possible. The fresh air temperature A is therefore decisive for the efficiency of the installation, which is completely inoperative above 31°C.

Once compressed to P ₀ + 16 hρg = 5.7291 MPa and cooled in the pin "o" - "o'", the gas (51) is introduced into the condenser (55) and the vapor separator by centrifugation ( 68) of figure 20. The section of this pin "o"-"o'" is larger than the others because it encompasses the last two decompression pins "o''"-"o'''" and “p''”-“p'''” and optimizes cooling below 31°C. The gas (52) stripped of its carbon dioxide is then decompressed to (53) where its decompression partially compensates for the energy expended by the compression phase, the moments of the compression and decompression pockets being opposed as illustrated by the figure 9. It cools by decompressing via the pins “x''” - “x'''”. The collector leaving each sub-decompressor will enter concentrically inside the compression hairpin of the same stage to heat up and cool the gas conveyed by said hairpin via the thermal jumper.

The carbon dioxide extractor therefore uses a system of heat exchange thermal straps as complex as that of the isothermal boiler, but very different. As often in a compressor, the compressed gases are cooled at the outlet of each stage. The compressor-decompressor then benefits during the compression from a consequent cooling generated by the cooling of the decompressed gases. A supply of fresh air A helps keep the compressed gas below 31°C.

If it is not a question of perfectly isothermal decompressions because of the imperfection of the heat exchanges with the environment, it should be noted that the bells being virtual, the bodies of siphon which constitute them always remain at the same height, therefore at the same temperature and are not called upon to participate in the heat exchanges. It should also be added that the compression and decompression pins being associated in pairs to convey fluids having similar pressures, the thickness of the internal pin can be reduced, thus increasing the effectiveness of the thermal ramp that it constitutes. . Thermal suspenders therefore optimize heat exchange by bringing flows of comparable pressures but of different temperatures closer together depending on whether they are in the compression or decompression phase while keeping them separated by a thin partition. When the decompression pin, internal, comes out of the compression pin, external and concentric, its thickness will of course be increased to take account of its working pressure.

Figure 18 describes a generic compression-decompression stage.

The admission of the gas to be compressed at (60) - "x'" allows suction by the compressor part of the rotor into the cavity (56) above the gas-liquid interface which delimits it. The rotation of this compressor traps the gas above the interface of the virtual bells formed by the helical siphons; this rotation also determines their depth within the pressure gradient of the liquid column below the interface of the cavity (56) and compresses the gas trapped in said virtual bells. A fixed rabbet (62) at the scuppers penetrates a circular groove inside the rotor to separate this gas being compressed from the gas being decompressed. This rabbet (62) is integral with the frame, the rotor groove surrounds it without any particular friction. The gas is then compressed by the pressure difference hρg, then guided by a rotating rebate integral with the rotor (63) which will lead it through the rebate (67) to (64) after a little height and therefore useful pressure have were lost in the compression liquid. The fixed or rotating rabbets (63) and (67) thus guided the gaseous parts within the liquid. The compressed gas then exits to a 'y' cooling pin and then to the next 'y' stage.

The compressor part is integrally associated with a second layer of helical surfaces of opposite direction as illustrated by Figures 8 and 9 in order to allow the decompression of the gas arriving at (65) from a hairpin "y''" - "y'' '" by an insulated commutator along which runs the shaft transmitting the rotor movement from stage to stage. The gas to be decompressed is sucked under the part above the interface of the rotating rebate integral with the rotor (66) piercing the interface to form a neck and constitute a pocket of gas at (61) that the decompressor part of the rotor will take into account to decompress it to (59). By its moment illustrated in figure 9, the gas in decompression will participate during this phase in driving the rotor and therefore its compressor part. The decompressed gas (59) is then injected into the next stage part (65) via "x''" and "y''". The joint (58) allows the transmission of mechanical motion by shorting the pins "x''" - "x'''" and "y''" - "y'''". This seal (58) does not need to be a sealed stuffing box given that the pressures on either side are very close, it is above all a heat shield so as not to call into question the isothermal nature of decompression and efficiency of "x''", "x''" pins.

To take account of the variations in volume within the virtual bells, the compressor is equipped with a central channel of diameter R ₀ as illustrated in FIG. 3, the crown of the decompressor is equipped with scuppers. The compressor-decompressor assembly has zero buoyancy when all the virtual bells are nominally filled with gas so that friction is reduced to that generated by viscosity alone. A port (57) in the rabbet support frame (62) allows the recirculation of the compression liquid, as with the scrolls (36) of Figure 10.

The level of carbon dioxide in the mixture (50) will generally be in the minority. Relatively little dioxide will be extracted and the amount of residual gas (52) to be recompressed will be large. We can count in this mixture in (50) on typically 80% nitrogen, a little oxygen, the majority of the rest being water vapor and carbon dioxide. It is therefore clear that the decompression rate will be lower than the compression rate and that it will be necessary to expend mechanical energy driving the rotors to compensate for the difference.

Thermal motor

Figure 21 of the heat engine takes up many characteristics of figure 18. All that has already been exposed on the compressor with helical siphons, on the compression of virtual bells, on the compressor and decompressor association by two layers of helical surfaces of opposite directions as illustrated by Figures 8 and 9, on the central channel and the scuppers, on the zero buoyancy of the overall rotor, on the segmentation into sub-compressors and on the guides and gas separations by rabbets remain valid. This heat engine comes from the observation that with identical initial and final states of compression and decompression, rotation of the compressor-decompressor with helical siphons only consumes the energy due to viscosity, friction and imperfections in gas transfer. from the end of the compressor stage to the supply of the decompressor. The radii of the rotors are indifferent, the moments generated being compensated by the filling rates of the bells. If this were not the case, we would have unearthed a perpetual motor, naturally excluded here.

The idea consists in intercepting the gas leaving the compressor and heating it by an external source (70) in the cavity (71). This heating will expand the gas inside this cavity (71), lowering the level of the liquid until it reaches the suction level (74) of the decompressor. The configuration of the rabbets prevents this hot gas from returning to the compression bells, thus fulfilling a non-return valve function. Without heating, the bells of the compressor and those of the decompressor would follow adiabatic compressions and expansions and their moments towards the rotor would cancel each other out (up to friction and other resistances). With heating, the bells being compressed remain unchanged; on the other hand, the bells during decompression are filled with hot gas and occupy a larger volume than without heating throughout their adiabatic expansion. This difference in volume generates a driving moment that a generator (72) can collect. The expansion is considered to be adiabatic given the low heat exchange on either side of the diopters of the bells. On start-up, the pump (73) regulates the level of the cavity (71) of compressed gas so that the level after heating (74) corresponds just to the suction of the decompressor.

Figure 22 describes the location of two of the compression and decompression bells.

With efficiency of the order of 5% seen below and modest powers (14 W at 50°K temperature difference, 55 W for a temperature difference of 200°K for a 0.163 m radius rotor and 1.57 m long), this isothermal motor will only be of interest in a few restricted cases of weak thermal sources that cannot be exploited by other techniques. It would not be of interest without the extreme weakness of the viscous friction of support and sealing. It is possible to almost proportionally increase the available power and efficiency by multiplying the stages, at the cost of increased complexity. The increase finds its limits in the multiplication of thermal losses and especially the adiabatic decompression which will reduce the differences in temperature and volume of the bells at the same pressure.

Dehumidification by decompression beyond the dew point .

Figure 23 of the decompression dehumidifier beyond the dew point reproduces many elements of the carbon dioxide extractor. All that has already been exposed on the compressor with helical siphons, on the compression of virtual bells, on the association compressor and decompressor by two layers of helical surfaces of opposite directions as illustrated by figures 8 and 9, on the central channel and the scuppers, on the zero buoyancy of the overall rotor, on the guides and gaseous separations by rabbets and on the thermal braces remains valid. However, it is no longer a question of compressing a gas but this time of decompressing and therefore cooling the ambient air which contains water vapor beyond its dew point, the cooling of the largely predominant air making more than compensate for the warming caused by the condensation of water vapour. This is to reproduce the ascent of a gaseous particle on the ground which rises to begin to condense at the base of the clouds up to 100% humidity with a constant mixing ratio, continues its condensation until at the top of the mountain by remaining at 100% humidity but by reducing its mixing ratio and globally reproducing the foehn effect of a mountain exposed to the wind. The fog which thus forms by condensation on crossing the dew point can be conventionally dried by centrifugation.

The helical siphon compressor is therefore used in its decompressor-compressor form. The current emagrams (figure 24) show that a decompression down to 500 hPa (5 m of water column) makes it possible to extract a large proportion of the water vapor present.

The liquid column is suspended by low pressure from the top of the device, as in a suitably sized "bird trough"; this low pressure initially comes from an auxiliary helical siphon compressor (78) which raises the level of the column. In the decompressor-compressor, the operation of the decompression part (external) of the rotor will create a suction of aspiration of the gas through the retention of the liquid forming neck (75). If the rotor stops, the suction ceases and the liquid remains suspended by the depression in the upper part. During its decompression, the mass of air and the water vapor sucked in via the neck (75) cool adiabatically to the dew point of the latter. The condensation of water vapor then begins, the heat of this condensation being transferred to the surrounding air. The continuation of the decompression is characterized by two antagonistic phenomena: on the one hand the air particles, largely in the majority, will continue to cool while relaxing, on the other hand the water vapor will continue to condense while transferring its heat of condensation to the ambient air. This decompression with change of state is called "wet adiabatic" or "pseudo-adiabatic" because if no heat is exchanged with the outside (the rotor and the bells are carefully insulated), the internal air-vapor exchanges of water reduce the typical thermal gradient from 10°C every 100 hPa to 6°C every 100 hPa. Throughout the "pseudo-adiabatic" decompression, the water vapor condenses into fine droplets or mist, with a low speed of fall within the virtual bells given the small size of these droplets. If very little will mix with the liquid of the compression gradient constituting the base of the virtual bells, they will nevertheless be recovered by the overflow (23). At the end of the decompression down to about 500 absolute hPa, the mixing ratio read on the emagrams shows that there is significantly less water vapor left to condense, as well as the illustration of one embodiment shown here. below shows it. At the outlet of the decompressor, a centrifuge concentrates the vapors obtained and the liquid produced is compressed to atmospheric pressure by a pump (76) in order to be extracted. The remaining gas cooled by decompression and then dehumidified by the centrifuge is reheated by the gas entering the heat exchanger (77) of the thermal jumper and then compressed to atmospheric pressure by the compression part (internal) of the rotor before be rejected. The cable gland (58) allows the mechanical shaft of the motor to pass through the casing of the thermal jumper. The cooling of the incoming air by the decompressed and dried air makes it possible to reach the dew temperature more quickly. Compression partially offsets the energy cost of decompression, but heating the gas before decompression reduces this compensation; calculations related to the heat engine show that the greater ease in reaching the dew point during decompression ultimately minimizes the mechanical energy required.

The example of an embodiment below shows that the gas volume increases by a factor of 1.8, which would correspond to an increase in the radius of the rotor by a factor of 1.34. This small increase shows that it is not necessary to use variable diameter rotors, which would complicate their manufacture and installation: it seems preferable to limit the flows injected at the base so that the expansion does not cause them to come out of the bells when expanded to 500 hPa.

Oblique axis buoy

In all of the above cases, the rotor was immersed in a liquid. It was designed to have zero buoyancy when all virtual bells are nominally filled with gas, so that friction is reduced to that which viscosity generates. To this end, the density of the materials used, the installation of hollow cavities and the use of ballast make it possible to limit the forces on the guide bearings of the rotor to the strict minimum.

The rotor of the compressor can also be outside a liquid and for the reduction of friction it is interesting to make it float on the liquid surface of a suitable capacity, by means of a float designed according to a profile adequate. This float is calculated to respect the angle taken as an example of β=45° with the vertical. It is made up of elementary discs corresponding to the generic section B-B' of figure 25, the submerged volume of which is constant. The surface of a segment of disk having R for radius and γ for half-angle at the vertex is:
s=R²(γ-sin(2γ)/2).

By noting γ₀the half-angle corresponding to the smallest of the elementary disks, we keep a constant surface if R(γ)= R(γ₀) for a disc located at x(γ)=R(γ) cos(γ) from the end of the compressor. γ will be between γ₀and γ_min, a γ_min low improving longitudinal stability. The overall buoyancy depends on R(γ₀), which determines the submerged volume and therefore the buoyancy. The profile of the float allowing the compressor to float and rotate freely with a determined inclination, illustrated at 45° in figure 25, is then determined by R(γ) respecting R(γ₀)²(γ₀-sin(2γ₀)/2)=R(γ)²(γ-sin(2γ)/2), γ being an implicit parameter varying between γ_ohand γ_min.

The center of the hull C _c is at a height determined by γ _c to have a disc segment half smaller than the initial segment, with 2γ-sin2γ= 4γ _c -2sin2γ _c .

Figure 25 provides a scale illustration of this float equipped with the helical siphon compressor in the liquid lifting version with its hull center C _c . The center of gravity C _g corresponds to the transverse metacentric center C _mt , ie it has no transverse stability as we have sought. On the other hand, the longitudinal metacentric center C _ml is located substantially above C _g , which guarantees good longitudinal stability. For the record, C _ml is at a distance from C _c equal to the metacentric radius r=I/V, I being the transverse quadratic moment of the flotation surface and V its submerged volume.

Figure 26 shows the float fitted with a helicoidal siphon compressor in gas compression version for oxygenation of the supporting liquid, for example a river. As in the previous cases, virtual bells suck in the gas and compress it by making it fall in the pressure gradient of the liquid. The central channel compensates for variations in the gas volume of the virtual bells. By floating on the surface of the liquid on which it is installed, the only forces that oppose its rotation are the viscosity of the float, the friction of the guiding system and of course the resisting torque of the compressor. Stability is maintained because the compressor (79) which was heavy in the air floats in the liquid and generates an equivalent moment.

Figure 27 shows the assembly of two floats so that the current of a river animates the compressor by means of the opposed pitch blades (80). Rotary joints (81) ensure the connection with two spacers (82). These spacers are secured by two frame parts (83) connected to the attachment point (84), itself located at the height of the center of the hull of the assembly so as not to interfere with its trim. The attachment piece (84) allows the mooring of this pair of floats to a conventional anchoring device (85).

Figure 28 is a simplification of Figure 27 with an oblique plane 80' to compensate for the yaw generated by the blades.

Figure 29 uses the oblique axis buoy perpendicular to the current. The attachment point 84 is positioned so that the buoy maintains this orientation.

Figure 30 does not use a helical siphon compressor, but a helical version pump to pour in liquid that should be comparably oxygenated. The interest of this variant comes from its greater narrowness.

Figure 31 is an allusion to the "Marly machine" for supplying water to the Palace of Versailles by means of 14 paddle wheels which animated three levels of pumps. Here, the paddle wheel (86) which can be a Darrieus or Savonius turbine for example drives four liquid lifting rotors, associated in accordance with Figure 6, that is to say without valve or stuffing box.

Figure 32 responds to the frequent need to valorize high flow rates with low driving head from a generator perspective. As with Poncelet, Sagebien or Zuppinger impellers, depending on the feed channels (87), the system avoids shocks and saves energy by requiring no prior acceleration of the flow; it also rejects the liquid (89) having worked at its initial speed. The gear train (88) associated with the cylindrical receivers with helical siphons makes it possible to collect the energies received and drive a generator (90).

Figure 33 corresponds on the contrary to the case of a high driving height, the cylindrical receivers with helical siphons are associated in sub-receptors according to the principle of figure 6, gradually decompressing the flow as it works in the sub -receptors. This device can also be used to decompress a collector.

Figure 34 combines the stages of Figures 31 and 33 to move liquids despite uneven ground, for example to pass over the pass that separates the Red Sea from the Dead Sea.

Brief presentation of the different figures

The present invention will be better understood and other advantages will appear on reading the detailed description of the different configurations, taken by way of non-limiting examples and illustrated by the attached principle drawings:

For didactic purposes, figure 1 depicts a tubular version of the helical siphon compressor with a liquid.

Figure 2 is the evolution of figure 1 to compress a gas.

Figure 3 shows the increase in the useful displacement between two helical surfaces, it also shows how the problem generated by the variations in level and the compressibility of the gases is solved by the installation of a central channel.

Figure 4 describes the different supply and discharge phases of a liquid by the system of Figure 3

Figure 5 shows the different phases of gas supply, compression and then rejection.

Figure 6 shows the combination of several liquid lift systems to fragment compression and improve compactness.

Figure 7 shows the association of several gas sub-compressors to improve the compactness of the overall compressor.

Figure 8 associates two series of helical surfaces of opposite directions to recover by decompression a large fraction of the energy expended by compression.

Figure 9 shows the opposing moments of the compression and decompression virtual bells.

Figure 10 is the application of the helical siphon compressor to the isothermal boiler.

Figure 11 describes the adaptation of a compressor to low compression and high flow.

Figure 12 details the operation of this low compression, high flow compressor.

Figure 13 describes the degassing module that the mechanical isothermal boiler can use.

Figure 14 depicts the lyophilization.

Figure 15 depicts alcoholic distillation.

Figure 16 describes the association of the stages of the helicoidal siphon compressor for the liquefaction of CO2.

Figure 17 describes the cooling chimney of the various manifolds of the helical siphon compressor for CO2 liquefaction.

Figure 18 depicts an intermediate stage of the helical siphon compressor for CO2 liquefaction.

Figure 19 depicts the initial stage of the helical siphon compressor for CO2 liquefaction.

Figure 20 depicts the final stage of the helical siphon compressor with centrifugal separation of liquid CO2.

Figure 21 describes the heat engine that can constitute a helical siphon compressor-decompressor.

Figure 22 details the route of the combustion engine compression and decompression bells.

Figure 23 describes the application of the helical siphon compressor to the dehumidification of a gas by decompression beyond the dew point and reproduction of the Foehn effect.

Figure 24 illustrates by an emagram the change of state responsible for the dehumidification of a gas by decompression beyond the dew point and reproduction of the Foehn effect.

Figure 25 depicts a rotating float supporting a helical siphon compressor in liquid lift version.

Figure 26 depicts the support of the helical siphon compressor by a rotating float.

Figure 27 describes the association of two rotating floats.

Figure 28 depicts the use of a single float with an anti-yaw plane

Figure 29 describes the use of a single float across the current

Figure 30 also depicts the use of a single float across the stream, replacing the helical siphon compressor for air with a helical siphon pump for water.

Figure 31 provides a use in "noria" or "Marly machine": the current of a river drives the base screw and generates a theoretically unlimited pressure.

Figure 32 shows how several screws can be combined to harness a low waterfall and collect mechanical energy.

In the case of a significant difference in level or the need to depressurize a liquid line, figure 33 shows how the screws can be associated by opportunely pressurized manifolds.

In an irrigation or water transport use, figure 34 shows how variations in the altitude of the relief can be taken into account.

Isothermal boiler

The isothermal boiler uses five enclosures subjected to atmospheric pressure on the outside and only 23.14 hPa inside. This is the mechanical situation of a pressure pot brought to the boil and emptied of air, then cooled to room temperature; its opening without first opening the valve is almost impossible. This example thus shows that the resistance of a cylindrical enclosure of about thirty centimeters in diameter does not pose any difficulty.

The power compressor must be more than 2 meters in diameter, but the diameter and the resistance pressure of a submarine hull are more important. The use of frames and spars provides reasonable solutions for material resistance. The supply manifold must have a very neat sectioning (38) to allow the dismantling of the enclosure (33) without losing the depression of the upper part of the inverted "u". To this end, the collectors (30) - (30 bis) and (31) - (31 bis) are also the subject of sections, much less critical because protected by the tank (20).

The copper heat exchanger (34) of the evaporator-condenser (29) has a thickness of the order of 1 mm as will be seen below and must withstand a pressure difference of 168 Pa, which does not poses no particular difficulty in terms of the strength of the materials.

The rotating parts undergo balanced pressures, they must only mechanically resist the torsion forces imposed by the transmission of the movement. These rotors are ballasted taking into account the nominal gas filling of the compression bells to correspond exactly to the density of the liquid(s) in which they rotate: oil + water for the power compressor (32), desalinated water for the auxiliary compressor ( 26). The forces on the bearings are thus reduced to a strict minimum. This is not the case of the pump (28) which is in the water vapor and must have more stressed bearings.

To be competitive with other desalination systems, the system must consume less than 2 kWh=7.2 10 ⁶ J per cubic meter produced, a value that can be retained initially before trying to reduce it. The 10 ⁶ /18 =55555 moles of a liquid cubic meter occupy a volume of 55555 8.31 293/2314 = 58455.91 m ³ at 23.14 hPa.

Assuming adiabatic compression with ϒ= 1.330 for H ₂ O at 20°C considered as an ideal gas, the work is W = (P ₂ V ₂ -P ₁ V ₁ )/( ϒ-1) = nR (T ₂ -T ₁ )/(ϒ-1), hence (T ₂ -T ₁ )=W (ϒ-1)/nR =7200000 0.33/(55555 8.31) = 5.14° K, hence T ₂ =298.14°K.

By P ₂ =P ₁ , we obtain P ₂ -P ₁ = P ₁ ( .-1) = 168 Pa, hence h= P/ρg= 1.86 cm with at ρ = 920 kg/m ³ for an oleaginous fluid.

For a radius R = 1 m, Figure 11 shows that a compressor inclined at 10° must measure a length of approximately 5.9 m to meet the requirement. The volume of the bells being difficult to evaluate, it was reduced by that of an elliptical cone πabh/3 inscribed inside the bell. A geometric study shows that displacement is optimized by increasing the number of interlaced helical surfaces that do not mutually interfere with each other, with a suggested solution of 12 helical surfaces. A greater number of helical surfaces would be even more favorable, at the cost of increased construction complexity, ruled out at this stage. In this case, with a pitch p/r = 3.1, the bells occupy a height of 0.284 m for 1.22 m in front and 5.44 m in depth, i.e. a unit volume of 0.49 m ³ and a overall volume of 5.92 m ³ . For example, a pitch p/r = 1.45 offers a unit volume of a bell of 1.04 m ³ but only 3 helical surfaces can be integrated (3 x 1.04 < 12 X 0.49) . A rotation speed of 120 revolutions/min, i.e. 2 revolutions/s corresponding to a period of 0.5 s provides a flow rate of 5.92/0.5=11.84 m ³ /s.

The number of moles compressed per second is of P 2314*11.84/(8.31*293) = 11.25 moles/s ≈ 202 g/s=729 kg/h = 17.5 t/d.

The enthalpy difference at the pressure of 23 hPa, i.e. the latent heat of evaporation and condensation, being approximately 2455 kJ/kg, the thermal power exchanged is 497 kW = 2455*0.202 .

The length of the cylindrical heat exchanger (34) with external and internal radii of 31 and 30 mm in copper (thermal conductivity λ=386 W m ^-1 K ^-1 ) necessary to transfer 494 kW under a temperature difference of 5.14 °K is L= Ln( ) = Ln(0.031/0.03) = 1.31m. An aluminum tube (λ=204 W m ^-1 °K ^-1 ) would require 2.47 m. These orders of magnitude indicate that the dimensioning of the necessary exchanger is reasonable.

Extraction of carbon dioxide by liquefaction

On suction, we keep an internal radius of 1 m and we choose an external radius of 1.41 m ( ) to obtain that the external crown has a passage section identical to that of the internal disc. The bells of the compressor of β=45°, p/r = 0.5 measure 1.38 m across, 1 m wide and 0.256 m high, i.e. a lower volume πabh/3 extended to 12 bells of 1.10 m ³ . The speed of 120 rpm makes it possible to obtain a suction flow rate of 2.22 m ³ /s or 2220/22.4 = 99.1 moles/s. As the aspirated gases are typically composed of 20% CO ₂ and 80% N ₂ , one can count on 0.44 m ³ /s of CO ₂ and 1.78 m ³ /s of N ₂ , i.e. with one mole for 0.0224 m ³ at 100,000 Pa respectively 19.64 and 79.46 mol/s or 0.86 and 2.23 kg/s (molar masses of 44 g and 28 g), i.e. 75 tons of CO ₂ per day .

To obtain at the output of the sixteenth sub-compressor a pressure of 5.7291 MPa, each sub-compressor generates overpressures of 351,819 Pa, i.e. the level difference P/ρg of the barite of a density of 2500 kg/m ³ is 14.345 m (5,729,100 -100,000)/(16*9.81*2500). The section of each sub-compressor being inversely proportional to its pressure, the last stage has an internal radius of 13 cm and an external radius of 19 cm. This characteristic is advantageous in terms of the resistance of the materials, an enclosure resistant to high pressure being easier to obtain for a small diameter.

Isotherm: power = RT Ln(Pb/Pa)

The 19.64 moles per second of CO ₂ which will not take part in the decompression consumed 193.611 kW to be compressed from 100,000 Pa to 5,729,100 Pa. To respect the isothermal nature of the compression of carbon dioxide, the same quantity of 193.11 kW must be evacuated through the chimney. This power developed for one hour makes it possible to produce 3.11 t. It therefore takes 62.2 kWh per tonne. At €0.05 per kWh, the minimum compression cost for a tonne of liquefied carbon dioxide is €3.11/t.

The latent heat of condensation is 152.00 kJ/kg. With a flow rate of 0.86 kg/s, the power required to evacuate is 131 kW.

On balance, the chimney must:

• cool the incoming gases whose temperature is unknown to the lowest possible temperature,
• absorb the 193 kW of carbon dioxide compression which is not compensated by any decompression,
• absorb the 131 kW required for condensation,
• participate in the heat exchange between the nitrogen during compression and the nitrogen during decompression,

Figure 17 is only a configuration illustration, other configurations may be better depending on the heat fluxes involved, especially that of the incoming gases.

Thermal motor

On suction, an internal radius of 0.1 m is used and an external radius of 0.163 m is chosen as illustrated in figure 22 and calculated below to prevent the gases heated and then expanded by decompression from coming out of their bell. We choose k=5 to have a total length of 1.57 m, i.e. a height difference of 1.11 m (1.57/ ). Sixty bells (5 x 12) are therefore simultaneously in decompression. The bells of the compressor of β=45°, p/r = 0.5 measure 0.138 m across, 0.1 m wide and 0.0256 m high, i.e. a volume reducing πabh/3 by 92.5 cm ³ containing 4.12 10 ^-3 mole under normal conditions. The 12 bells occupy a volume of 1.1 liters. The speed of 300 rpm makes it possible to obtain a suction flow rate of 5.5 l/s or 5.5/22.4 = 0.25 mol/s = .

The thermal power to increase the temperature by 50°C is CvΔT with Cv = R/(ϒ-1) and ϒ=1.4 for diatomic oxygen and nitrogen in air, i.e. 260 W.

As illustrated in figures 21 and 22, under the effect of the lowering of the bell, the 92.5 cm³of gas at 293°K during compression of P_h=100000 Pa to P_b = 110000 Pa will heat up by being adiabatically compressed at T_b= T_h = 301.1°K. The new volume is:

V _b = V _h =86.4 cm ³ .

After being heated from 50° to T' _b = 351.1°K, the 4.12 10 ^-3 moles at pressure P _b occupy a volume of V' _b =V _b T' _b /T _b = 100.7 cm ³ .

For our calculation, these 4.12 10 ^-3 moles in their 60 bells will decompress to P _h . Each of the 60 bells is at a pressure P _i , P _i being regularly distributed between P _b and P _h with P _i = P _b + (P _b -P _h )/120 - i (P _b -P _h )/60.

It will be noted that at identical pressure P _i , the gaseous volume of the compression bell and that of the decompression bell without heating are identical and called V _i . For each bell in decompression, it is necessary to compare the volume with heating V' _i and without heating V _i , that is:

V _i = V _b and V' _i = V' _b The difference ΔV _i generates a moment ΔV _i Δρ g l. In accordance with figure 22, we will take a lever arm l of 5 cm. Δρ corresponds to the difference between the density of the liquid and that of the gas of 1000 kg/m ³ : according to Archimedes' principle, the thrust is equal to the weight of the displaced liquid volume. Another point of view is to observe that without heating, the moments of the bells in compression and in decompression are opposed; with heating, the balance is broken with a quantity of liquid in addition to the compressor side. The sum of the moments multiplied by the angular velocity gives the available power.

The numerical application of the 60 bells in decompression between 1100 and 1000 hPa shows without heating an expansion of 86.4 to 92.5 cm ³ , with 50°K of heating from 100.8 to 107.8 cm ³ , a difference of volume from 14.4 to 15.3 cm ³ , cooling from 351°K to 341.7°K.

The moments of each bell vary from 7.0 to 7.5 10 ^-3 Nm, with a sum at 0.44 Nm With a rotational speed of 5 rpm = 31.4 rad/s, the total power is 13.7 W. The efficiency of 13.7/260 is 5.3%.

Decompression bells must be large enough to collect all gases. If the heat engine is sized for a difference of 200°K, the volume at the outlet of the decompressor is 153.9 cm ³ , i.e. an increase in volume and therefore in surface area compared to the initial volume at the compressor inlet of 1.7 , i.e. an external radius of 0.10 =0.163m.

The numerical application with an internal rotor of 1 m radius for k=1 indicates a power of 2.6 kW and an efficiency of 1%.

As a reminder, it is possible to almost proportionally increase the available power and the efficiency by multiplying the stages according to the principle of figure 16, the limit coming from the progressive reduction of the differences in temperature and volume of the bells at the same pressure.

Dehumidification by decompression beyond the dew point

The example of an air mass at a pressure of 1013 hPa at 30°C and 30% relative humidity provides an order of magnitude for the case of an atmosphere low in humidity (the northern Sahara has 20% 30% humidity in summer and 50% to 60% in January). The Gustav Magnus-Tetens formula T _r = (0.9 T-112) +0.1 T – 112 (temperature T and dew temperature Tr in degrees Celsius, H relative humidity) gives a dew temperature of 10.6°C. The emagram in Figure 24 indicates that the mixing ratio is then 7.5 g of water per kilogram of air and that condensation begins at a pressure of 800 hPa (about 2000 m in a standard atmosphere) with a temperature 7°C. This emagram is simplified insofar as the adiabats, with low curvature, are for convenience represented by straight lines. Expansion up to 500 hPa (about 5600 m) according to the wet adiabatic leads to a mixing ratio of 2.2 grams of water vapor per kilogram of air, i.e. 7.5 -2.2 = 5.3 grams of water per kilogram of air has condensed and is available for centrifugal extraction. But the temperature of this air mass is -16°C at 500 hPa, for a dew point of -7°C at 1013 hPa with a temperature of about 43°C.

It may be feared that the insulation is not capable of allowing wet adiabatic decompression down to -16°C: the real wall of each virtual bell comes into contact with the liquid of the compression gradient at each revolution. The content of the virtual bells will then heat up in contact with said wall, the exchanges will not be perfectly adiabatic and we can accept the hypothesis of a final decompression temperature at 500 hPa of -16°C by -10°C. The mixing ratio in this case is 3.5 grams per kilogram, ie 7.5-3.5=4 grams per kilogram available for extraction by centrifugation. With 2.22 m ³ /s of air flow and an air density of 1.225 kg/m ³ , a production of 940 kilograms per day is obtained. At the end of adiabatic compression, the temperature at the pressure of 1013 hPa is 50°C. For the record, a humidity level of 60% under the same conditions would produce a throughput of 2937 kilograms per day.

The small amounts of water produced correspond to the dryness of the atmosphere used; in these regions often devoid of cloud cover, the abundance of solar energy can compensate for the low production and justify the investment. Implementation of the heat engine described in the present invention would improve efficiency by using the heat rejected by the compressor.

We can also notice the low gain obtained by a decompression beyond 500 hPa, the limit of insulation at -10°C constitutes the main obstacle to production.

Oblique axis buoy

We can design a compressor with a radius of 0.1 m whose twelve bells would have a capacity of 1.1 liters. Choosing k=5 would compress air to a depth of 1 m. Depending on the speed of the current, the size and pitch of the blades (80), the quality of the rotating joints for mooring, a speed of 3 revolutions per second seems possible. 3.3 liters per second at 1 m of immersion corresponds to a power of d h ρ g = 32 W, which seems consistent for a small tidal turbine.

Invention capable of industrial application

The helical siphon compressor will be composed of shrouds illustrated in FIG. 9 consisting of two assemblies of helical surfaces of opposite direction, each welded according to their maximum radii (5) and (17) in FIG. 8 on two cylinders. The helical surfaces, in which the scuppers are drilled, are welded to the radius cylinder (16) to secure the two assemblies. Each ferrule will have assembly crowns in the upper and lower parts (18), not shown, making it possible to mechanically associate two ferrules with each other and to guarantee their tightness by a seal between each pair of ferrules. With a radius (5) of 1 m, each ring according to the pitch p=r/2 will have a height of 3.14 m. Helical surfaces are developable surfaces, i.e. they can be obtained from a flat sheet which will be shaped into a helical shape. For a radius (5) of 1 m, the welds will use helical guide tools to position the welding tool. The central channel (14) will be obtained by the initial machining of the shaped flat sheet. For smaller radii (5), the ferrules can be obtained by three-dimensional printers.

When the height of the helical radius compressor required does not correspond to an integer number of shell heights, the last shell can without damage be composed of a fraction of the shell which does not have identical upper and lower sections (18).

The heat exchanger of the isothermal boiler constitutes by its internal part a condenser whose operation is improved by radiating plates (48). The low pressure difference makes it possible to use a shaped and tin-soldered copper foil. This is not the case with the condenser of the carbon dioxide extractor which must withstand a pressure difference of 5.6 MPa, a conventional copper pipe will be used in this case.

Claims (10)

Helical siphon compressor, used as an isothermal boiler, carbon dioxide extractor, heat engine, dehumidifier by decompression beyond the dew point or buoy with oblique axis, characterized in that it comprises bells in translation determined in firstly by a cylindrical wall (5) of radius R ₁ , secondly by a central cylindrical channel (4) of radius R ₀ , thirdly by a helical wall between the central channel (4) and the wall (5) , fourthly by a horizontal surface inside a level line (7) resting on the upper point (7') of the intersection between the central channel and the helical wall and lastly by the inclination of the cylinder (5) and of the central channel (4) with respect to the horizontal, on the other hand by positioning a gas-liquid interface (3) distributing said bells in translation between suction bells and bells compression: above the diopter (3), the suction bells are full of gas, a rotation of the compressor translates them downwards until the level line (7) reaches the diopter (3) and isolates the gas pockets they contain; below the diopter (3), said pockets of gas isolated by the bells in translation undergo the pressure gradient of the column of liquid under the diopter (3) via the surface inside the line of level (7) and are compressed accordingly. Helical siphon compressor according to Claim 1, used as an isothermal boiler, carbon dioxide extractor, heat engine, dehumidifier by decompression above the dew point or oblique axis buoy, characterized in that the central channel (4 ) of radius R ₀ introducing on the one hand inside the bells in translation the liquid compensating for the variation in volume of the compressed gases and making it possible on the other hand to overcome the position of the interface (3) with respect to the ends (6) of the compressor. Helical siphon compressor according to Claims 1 and 2, used as an isothermal boiler, carbon dioxide extractor, heat engine, dehumidifier by decompression above the dew point or an oblique axis buoy, characterized in that it comprises a rotor at zero buoyancy when all bells in translation are nominally filled with gas so that friction is reduced to that generated by viscosity. Helical siphon compressor according to claims 1 to 3 used as an isothermal boiler, carbon dioxide extractor or dehumidifier by decompression above the dew point characterized in that it comprises thermal suspenders (34) or 'x''” - “x'''” (“x” between “a” and “p”) or (77) bringing flows together at different temperatures while separating them by a thermally conductive partition. Helical siphon compressor according to Claims 1 to 4 used as a carbon dioxide extractor, heat engine or dehumidifier by decompression beyond the dew point, characterized in that it integrally associates two layers of helical surfaces of opposite directions allowing simultaneous compression and decompression of two gas streams. Helical siphon compressor according to one of Claims 1 to 3 used as a carbon dioxide extractor and heat engine, characterized in that it is segmented into progressively pressurized sub-compressors in order to reduce the overall size of the device and to transmit the drive movements without any sealing device. Inverted "U" tube housing a helical siphon compressor according to claims 1 to 3 and used as an isothermal boiler, characterized in that the branches of the inverted "U" are filled unequally (24) and (25) due to the use in one of said branches of a layer of liquid (edible oil) with a density slightly lower than that of the salt water of the other branch but with a saturation vapor pressure much lower than that of the said salt water, said layer of edible oil preventing the evaporation of the desalinated water above which it is located. Evaporator-condenser fed by a helical siphon compressor according to one of Claims 1 to 4 and 7 and used as an isothermal boiler, characterized in that it comprises a removable enclosure in which there is a heat exchanger (34), radiating plates (42) inside the heat exchanger (34) allowing the heat flow between the inside and the outside of said exchanger to bypass the screen formed by the condensed water in its lower part (41) and therefore to increase said heat flux. Helical siphon compressor according to Claims 1 to 6, used as an isothermal boiler, carbon dioxide extractor, heat engine and dehumidifier by decompression above the dew point, characterized in that it comprises baffles, fixed rabbets or rotating (15), (62), (63), (66), (67) for guiding the gaseous flows within the liquid or for separating different gases. Helical siphon compressor according to claims 1 to 3 used as an oblique axis buoy,characterized in that it comprises a float, the float of which allows the compressor to float and rotate freely with a determined inclination, in particular 45°; said profile is then determined by R(γ) respecting R(γ₀)²(γ₀-sin(2γ₀)/2)=R(γ)²(γ-sin(2γ)/2), γ being an implicit parameter varying between γ_ohand γ_min.