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Title:
EMULSION MARINE PUMP
Document Type and Number:
WIPO Patent Application WO/2019/123330
Kind Code:
A1
Abstract:
The marine pump object of the present invention is a hydro pneumatic machine, driven by wave motion - a wave energy converter (WEC) - characterized in that it does not have moving mechanical members and it is constituted by only two structural components: a box-shaped body, open at the base, partially immersed in the water of the sea, and a tube, joined together to form a single body. The particular shape of the body and the way in which it is connected to the tube allow the pump to operate in one part, like an air compressor, in the other, like an airlift. The pump can be used specially for deep water lifting (upwelling); either for sinking of the superficial ones (downwelling); or also - acting as a submerged air hydro-compressor (trompe) - for sinking of surface waters, their oxygenation and the simultaneous production of compressed air.

Inventors:
COSSU BRUNO (IT)
CARLO ELIO (IT)
Application Number:
PCT/IB2018/060364
Publication Date:
June 27, 2019
Filing Date:
December 19, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
COSSU BRUNO (IT)
International Classes:
F03B13/14; B63B35/00; E02B1/00; F04B17/00
Domestic Patent References:
WO2007038689A22007-04-05
WO2016046689A12016-03-31
Foreign References:
JP2000104653A2000-04-11
US20090173386A12009-07-09
US3754147A1973-08-21
Other References:
CHEN JIAWANG ET AL: "Development of air-lifted artificial upwelling powered by wave", 2013 OCEANS - SAN DIEGO, MTS, 23 September 2013 (2013-09-23), pages 1 - 7, XP032567874
NAI KUANG LIANG: "A Preliminary Study on Air-Lift Artificial Upwelling System", 1 January 1996 (1996-01-01), XP055490880, Retrieved from the Internet
ZHANG DAHAI ET AL: "Reviews of power supply and environmental energy conversions for artificial upwelling", RENEWABLE AND SUSTAINABLE ENERGY REVIEWS, vol. 56, 17 December 2015 (2015-12-17), pages 659 - 668, XP029387071, ISSN: 1364-0321, DOI: 10.1016/J.RSER.2015.11.041
PAN YIWEN ET AL: "Research progress in artificial upwelling and its potential environmental effects", SCIENCE CHINA EARTH SCIENCES, SCIENCE CHINA PRESS, HEIDELBERG, vol. 59, no. 2, 10 December 2015 (2015-12-10), pages 236 - 248, XP035939832, ISSN: 1674-7313, [retrieved on 20151210], DOI: 10.1007/S11430-015-5195-2
GOPALAKRISHNAN A.: "Artificial Ocean fertilization and marine fisheries - An Introduction", NASS RESEARCH EDUCATION AND TECHNOLOGY POLICY FORUM, vol. 16, no. 4, 2016
QUCHI K.; OGLWARA ET AL.: "Ocean nutrient Enhancer: Creation of Fishing Ground Using Deep Ocean Water", OMAE2002-28355, 2002, pages 851 - 856
KIRKE B: "Enhancing fish stocks with wave-powered artificial upwelling Ocean Coast", MANAG, 2003, pages 901 - 915
MCKINLEY K.R.; TAKAHASHI P.K.: "Deep ocean water, artificial upwelling, and open ocean mariculture: A promise for the future", vol. 1, 1991, IEEE, pages: 195 - 199
YANG J.; ZHANG D. ET AL.: "Feasibility analysis and trial of air-lift artificial upwelling powered by hybrid energy system", OCEAN ENGINEERING, 2017, pages 520 - 528
ZHANG D.; FAN W. ET AL.: "Reviews of power supply and environmental energy conversions for artificial upwelling", RENEW. SUSTAIN. ENERGY REV., 2015, pages 659 - 668, XP029387071, DOI: doi:10.1016/j.rser.2015.11.041
DUNN S.; DHANAK M. ET AL.: "Artificial upwelling for environmental enhancement", RETOUR CLUB DES ARGONAUTES - DOSSIER ENERGIE THERMIQUE DES MERS
PAN Y.; FAN W., EVALUATION OF THE SINKS AND SOURCES OF ATMOSPHERIC C02 BY ARTIFICIAL UPWELLING
MILLER A.F., MITIGATING ALMOST 1.5° C OF GLOBAL WARMING USING OTEC-INDUCED ARTIFICIAL OCEAN UPWELLING
KITHIL P.W.: "Using oceanic forced upwelling and downwelling to mitigate rapid climate change in the North Atlantic", ATMOCEAN, INC.
PAN Y.; FAN W. ET AL.: "Research progress in artificial upwelling and its potential environmental effects", SCIENCE CHINA EARTH SCIENCE, 2015
YANG J.; ZHANG D. ET AL.: "Feasibility analysis and trial of air-lift artificial upwelling powered by hybrid energy system", OCEAN ENGINEERING,, 2017, pages 520 - 528
PELEGRI J.L.; VAQUE D.: "Artificial upwelling using offshore wind energy for mariculture applications", PLANET OCEAN, SCIENTIA MARINA, September 2016 (2016-09-01), pages 235 - 248
CHEN J. W.; YANG J ET AL.: "Development of air-lifted artificial upwelling powered by wave", MTS/IEEE OCEANS CONFERENCE, 23 September 2013 (2013-09-23), pages 1 - 7, XP032567874
LIANG, N.K.: "A Preliminary Study on Air-lift Artificial Upwelling System", ACTA OCEANOGR, 1996, pages 187 - 200
WALID A.A.; SALAMA ABDEL--HADY M. ET AL.: "Performance Analysis of Low Head Hydraulic Air Compressor", SMART GRID AND RENEWABLE ENERGY, vol. 1, 2010, pages 15 - 24
HOWEY D.A.; PULLEN K.R., HYDRAULIC AIR PUMPS FOR LOW-HEAD HYDROPOWER
BELLAMY N.W.: "Low-head hydroelectric power using pneumatic conversion", POWER ENGINEERING JOURNAL, 1989
PAVESE V.; MILLAR D.; VERDA V.: "Mechanical Efficiency of hydraulic air compressor", JOURNAL OF ENERGY RESOURCES TECHNOLOGY, 2016
MILLAR D.; MULLER E.: "Hydraulic Air Compressor (HAC) Demonstrator Project", ACEEE SUMMER STUDY ON ENERGY EFFICIENCY IN INDUSTRY, 2017
MCCORMICK: "Ocean Wave Energy Conversion", 2007, DOVER PUBLICATIONS, pages: 61 - 66
Attorney, Agent or Firm:
PAPA, Elisabetta (IT)
Download PDF:
Claims:
CLAIMS

1. An emulsion pump for use in the sea directly actioned by wave movement comprising:

1.1 ) a tank, equipped with devices suitable for making it float, installed in a section of the sea characterised by intense and frequent waves, of a form that is substantially analogous to that of a mushroom (TAB. 1 , lett. A+B), the cap (TAB. 1 , lett. A) and stem (TAB. 1 , lett. B) of which are hollow, in which:

- the part corresponding to the cap (TAB. 1 , lett. A) acts as a compressor (hereafter: compressor); surrounds an air chamber; is preferably of such a shape that its volume, in the part that remains above the waterline when the sea is peaceful, increases in height in a manner that is less than proportional; is as high, approximately, as the significant height of the waves that are recorded on-site; is immersed, when the sea is calm, by about one third/one quarter of its overall height; its base is open; its lateral surface has a strip of about 5-10 cm long above the waterline which is crossed by numerous holes (TAB. 1 , lett. C); is equipped, preferably at the height of the waterline, with handles (TAB. 1 , lett. D), or other devices, at least three, for hooking the anchor chains;

- the part that corresponds with the stem (TAB. 1 , lett. B) operates as the pipe of an airlift (hereafter: air lift pipe); it is set up as a section of rectilinear pipe made of rigid material open at both ends; immersed vertically in the sea water by at least 12 metres; the surface of which, starting from a few decimetres below the free water surface of the sea when calm, is crossed by numerous holes (TAB. 1 , lett. E), of a diameter that slowly increases with the depth; the upper extremity of which, after having crossed the roof of the cap, stops at its height or just above it;

1.2) a delivery pipe (TAB. 1 , lett. F) made of a section of pipe; of rigid material; open at both extremities; integral with the tank; co-axial with the part of said tank that acts as the air lift pipe; of a slightly bigger diameter than said air lift pipe; the upper extremity of which is positioned at a height of 5-10 cm below the roof of the tank; the lower extremity, which acts as an intake mouth (TAB. 1 , lett. F1 ) at a depth just below that at which the lower extremity of the part of the tank that acts as the air lift pipe is;

1.3) a feed pipe that feeds compressed air to the air lift pipe and a suction pipe that sucks the atmospheric air into the tank, made up of a pipe with a circular crown section made up of the interspace between the delivery pipe and the air lift pipe (TAB. 1 , lett. G);

1.4) a diffusor - through which the compressed air can spread inside the air lift pipe and the atmospheric air can spread inside the pipe indicated in the previous point and thenceforth into the tank - made of the set of holes (TAB.

1. lett. E) present in the air lift pipe;

1.5) a series of devices or structural elements that make it possible to unite the various system components to each other, in such a manner as to form a single unit;

1.6) an anchoring system, made up of at least three chains (TAB. 1 , lett. H), the extremities of which are hooked to the tank, the lower ones being fixed to the sea bed by heavy anchors or other systems; the length of which substantially coincides with the distance between the sea bed and the hooking devices present on the tank, which therefore cannot rise above the water surface when the sea is calm.

2. The emulsion pump for use in the sea directly actioned by wave movement recited in claim 1 , wherein:

2.1 ) the delivery pipe is very short, and has the same diameter as the air lift pipe; is united physically to said air lift pipe so that the two pipes, even though remaining functionally distinct, create a single lifting pipe (TAB. 2, lett. i);

2.2) the compressed air feed pipe is made of a pipe with a circular crown section formed of the interspace (TAB. 2, lett. G) between the air lift pipe and another pipe that is co-axial to it (TAB. 2, lett. L) and having a slightly bigger diameter than it, the lower extremity of which is closed and positioned at a depth such that the air lift pipe meets with the delivery pipe; the upper extremity is positioned at a height of approximately 5/10 cm below the roof of the tank.

3. The emulsion pump for use in the sea directly actioned by wave movement recited in claim 2, wherein:

3.1 ) the lifting pipe (TAB. 3, lett. I) does not have holes, even in the section where it operates as an air lift pipe;

3.2) the compressed air feed pipe is made up of a pipe (TAB. 3, lett. M), open at both extremities, or only at the upper extremity; having a diameter greatly smaller than that of the air lift pipe; that is inner and usually co-axial to it for almost all its extension; the surface of which, starting from a few decimetres below the water surface when the sea is calm, is crossed by numerous holes (TAB. 3, lett. E), of a size that gradually increases with the depth; the upper terminal section of which, after having crossed the air lift pipe, stops at a height of a few decimetres below the tank roof.

4. An emulsion pump for use in the sea directly actioned by wave movement for raising deep water, made up of any of the pumps recited in claims 1 , 2 and 3 in which the intake mouth of the delivery pipe is united with a flexible pipe - an upwelling pipe - along various hundreds of metres or even more, with the lower extremity acting as an intake mouth, and being positioned at the depth at which the water to be lifted can be found.

5. An emulsion pump for use in the sea directly actioned by wave movement for raising deep water recited in claim 4 wherein a buoy maintains the last 5- 10 metres of the upper section of the upwelling pipe in a horizontal position or at such an angle that the vertical movement of the tank involves only this section and not the whole piping.

6. An emulsion pump for use in the sea directly actioned by wave movement or raising deep water and transferring it through gravity to the place of use made up of any of the pumps recited in claims 4 and 5, wherein:

6.1 ) the upper extremity of the air lift pipe does not stop at the height of the roof but exits from it by one or more metres, emerging inside a container - usually a larger pipe, closed at the bottom - that acts as a tank for collecting and loading the lifted water separated by emulsion;

6.2) the system also includes another pipe - the upper extremity of which acts as an intake mouth and emerges inside the tank, at the height of its base; the lower extremity, which acts as a discharge mouth, reaches the place where the water is to be used and is positioned at a lower quota than the surface of the water that collects in the collecting tank - which transfers the water that slowly flows into the loading tank to the place where the water is to be used.

7. An emulsion pump for use in the sea directly actioned by wave movement for lowering surface water, made up of any of the pumps recited in claims 1 and 2, wherein:

7.1 ) the diameter of the air lift pipe, in the case of claim 1 , or of the raising pipe, in the case of claim 2, is bigger (TAB. 4, lett. I) than the one used for the pumps indicated in these claims; its upper extremity (TAB. 4, lett. N) exits from the compressor roof and stops about one meter higher than the height at which the air-water emulsion is lifted;

7.2) inside the air lift pipe, in the case of claim 1 , or the raising pipe, in the case of claim 2, there is positioned another pipe (TAB. 4, lett. 0) - which acts as a pipe for discharging the surface water lifted - co-axial to said pipes; having a diameter that is slightly greater than half that of the latter pipes; the upper extremity of which - acting as an intake mouth for the water separated from the emulsion - is positioned at a lower height than that at which the emulsion is lifted; the lower extremity of which reaches the depth at which the lifted water is to be discharged.

8. The emulsion pump for use at sea directly activated by wave movement for re-lowering surface water recited in claim 7, wherein:

8.1 ) the intake mouth of the delivery pipe (TAB. 5, lett. T) opens inside another pipe (TAB. 5, lett. P), to which it is solidly joined, having a diameter that is more than double, closed at the base, which operates as a supply tank for the delivery pipe, the upper extremity of which is positioned at a quota that is a little lower than that of the sea surface;

8.2) the discharge pipe (TAB. 5, lett. O) crosses the bottom of said supply tank.

9. The emulsion pump for use at sea directly activated by wave movement for raising surface water or deep water over several stages recited in claims 6, 7 and 8, wherein:

9.1 ) the upper extremity of the air lift pipe does not stop at the height of the tank roof but exits from it by at least one metre, opening inside a container, usually a pipe with a bigger diameter, closed at the base, which acts as a collection tank for the water emulsion that has been lifted and separated;

9.2) the water that gathers in the tank is further lifted by one or more airlifts in series, also supplied by the compressed air produced by the compressor.

10. An emulsion pump for use at sea directly activated by wave movement for surface water lowering, oxygenation, and the contextual production of compressed air made up of any of the pumps for lowering surface water recited in claims 7, 8 and 9 wherein the lower extremity of the discharge pipe (TAB. 6, lett. 02) is positioned at a depth corresponding to that at which the atmospheric air is to be compressed and includes the following additional components:

10.1 ) a Venturi pipe (TAB. 6, lett. Q), mounted on the upper extremity of the discharge pipe (TAB. 6, lett. 01 ), or just below it, the neck ratio of which is such that the water flowing into said narrow section has a lower pressure than the atmospheric pressure;

10.2) a suction pipe (TAB. 6, lett. R) or other device that allows the atmospheric air to flow into the narrow section of the Venturi pipe to mix with the water that flows into it;

10.3) a bell (TAB. 6, lett. S), inside which the lower extremity of the discharge pipe (TAB. 6, lett. 02) penetrates by about one metre, and in the upper part of which the compressed air is collected as it exits from said pipe;

10.4) a set of devices and/or structural elements that allow the bell to be integral with the lower extremity of the discharge pipe;

10.5) a pertinent pipe (TAB. 6, lett. T) which fluidly connects the upper part of the bell with the place of use/storage of the compressed air, equipped, on its lower extremity, with a float valve (TAB. 6, lett. U) or another closing device, which hydraulically disconnects said pipe from the bell when the level of water inside said bell reaches a specific height.

11. The emulsion pump for use at sea directly activated by wave movement for lowering surface water, oxygenating it and contextually producing compressed air recited in claim 10 wherein:

11.1 ) the delivery pipe, in the part below the air lift pipe, recited in claim 2, is at least 15/20 metres long;

11.2) a small part of the compressed air that collects in the bell is made to flow through a pertinent pipe immediately above the lower extremity of the delivery pipe which, therefore, is configured and operates also as an air lift pipe, making it possible to lift the water to the greatest height.

12. The emulsion pump for use at sea directly activated by wave movement recited in the previous claims, wherein the tank does not float but is joined, solidly, to a base fixed on the sea bed; or to another structure that forces it to maintain its position unaltered in spite of the wave movement; or is made up of a fixed structure, possibly englobed in the coast.

13. The emulsion pump for use at sea directly activated by wave movement recited in all the previous claims wherein said tank is divided vertically into sectors along about two thirds of its height by one or more walls inside said tank.

14. The emulsion pump for use at sea directly activated by wave movement recited in claim 12, wherein the tank is of greater height than the important wave that is registered on-site and the level of the water that is to flow inside it reaches higher than half its height.

15. The emulsion pump for use at sea directly activated by wave movement recited in claim 14, wherein:

15.1 ) the lateral surface of the tank is without holes;

15.2) the section of the air lift pipe, or the pipe that feeds the compressed air in the case of claim 3, the surface of which is perforated, begins from a few decimetres above the water surface when the sea is calm;

15.3) the anchoring system of the system in the sea bed and/or possibly another fixed structure allows the tank to oscillate following the movement of the waves.

Description:
EMULSION MARINE PUMP

DESCRIPTION Technical field of the invention

The present invention relates to the field of the machines aimed at harnessing sea energies and, in particular, wave energies ( wave energy converterANEC).

In its basic form, it relates to a hydro-pneumatic machine, driven by wave energy, characterized in that it has no moving mechanical parts and, in its main core, it is made up of only two structural components, a hollow body, open at the bottom and partially immersed in sea water, and a tube, both joined together to form a single body.

The shape of the hollow body is substantially like a mushroom whose cap and stem are hollow; the stem, in turn, is open at both ends and the lower section of its surface is crossed by holes; the tube is external and coaxial to the stem and it is joined thereto so as to form a single body. This particular shape of the hollow body and type of connection to the tube allows the pump to operate simultaneously as an air compressor on one side, the one corresponding to the cap, and as an airlift on the other side, the one corresponding to the hollow portion of the stem.

The pump substantially can be implemented in four versions, each one, in turn, provides several variants and implementation modes:

1. in a version, for the upwelling of cold and deep-sea water at the level of the sea surface ( artificial upwelling) · ,

2. in a second version, for the lifting and transfer of this water to the place of use, even if kilometres away;

3. in a third version, for the downwelling of surface sea water ( forced downwelling) · ,

4. in a fourth version, for the downwelling of surface water, its oxygenation and the simultaneous production of compressed air, substantially without additional energy costs. The transfer of deep water or the downwelling of the raised surface water, according to the pump versions indicated in points 2 and 3 above, is obtained by making the water raised by the air lift to flow to the upper mouth of another pipe, internal or adjoined to the air lift; the downwelling of raised surface water, its oxygenation and the simultaneous production of compressed air, according to the pump version indicated in point 4, is obtained by installing a Venturi tube on the upper end of the pipe, whose restricted section is connected to the external atmosphere, so that it (also) operates like a submerged water column, flowing water column hydraulic air compressor (trompe).

Furthermore, by combining one or more pumps for the upwelling of cold, deep water with one or more pumps for the downwelling of warm surface water, the system can be used in an OTEC plant, to supply the cold and warm water required for the operation of the same, thus allowing to use simultaneously, and without additional costs, in addition to the mechanical energy of the waves for the purposes indicated in points 1 to 4 above, even the thermal one of marine water treated in the process, for the production (electively) of electric energy.

All previously indicated fields, in which this pump can be applied, are particularly important. And in fact:

AS TO UPWELLING

The upwelling, in surface, of huge masses of cold and deep marine water allows to pursue simultaneously three fundamental goals:

- firstly, fertilization of oceans. In fact, it is known that deep water is rich in nitrates, phosphates and silicates, fundamental elements for phytoplankton development; moreover, it contains very few parasites and pathogen bacteria, so that the artificial upwelling is capable of increasing significantly the abundance of fish in marine areas in which it is caused (see“Artificial Ocean fertilization and marine fisheries - An Introduction”, Gopalakrishnan A., NASS Research Education and technology policy forum, vol. 16, no.

4/2016; “ Ocean nutrient Enhancer: Creation of Fishing Ground Using Deep Ocean Watef , Ouchi K., Oqiwara et al. , OMAE2002-28355, pages 851 -856; “Enhancing fish stocks with wave-powered artificial upwelling Ocean Coast’. Kirke B. Manag, 2003, pages 901 -915; “Deep ocean water, artificial upwelling, and open ocean mariculture : A promise for the future”, McKinley K.R., Takahashi P.K., 1991. IEEE 1 : 195-199); thus, by contributing to face the needs for nourishing the world population. One has only to consider that in the areas in which there is a natural upwelling - which represent less than 1 % of the total surface of the oceans - about 40% of the world catch can be fished (see“ Feasibility analysis and trial of air-lift artificial upwelling powered by hybrid energy system”, Yang J , Zhang D. et aL in Ocean Engineering, 2017, pages 520-528: “Reviews of power supply and environmental energy conversions for artificial upwelling”, Zhang D.. Fan W. at a!., Renew. Sustain. Energy Rev., 2015, pages 659-668);

- secondly, a decrease in the global warming. The upwelling of huge masses of cold water, by means of several (hundreds and hundreds of) pumps for the artificial upwelling (each one thereof lifts several cubic meters of water per second collected at a depth of at least 300 meters), involves not only, as immediate and direct effect, a several-degree decrease in temperature of surface water of large sea expanse, but even, and above all, an important decrease in the quantity of carbon dioxide existing in the atmosphere and, then, of the greenhouse effect considering that, on one side, the gas absorption capability by water increases considerably when its temperature decreases; on the other side, the fertilization of marine water, caused by the artificial upwelling, determines a huge development of phytoplankton which, in turn, is one of the main absorbers (indeed, together with ocean water) of carbon dioxide existing in the atmosphere (see “Artificial upwelling for environmental enhancement”, Dunn S., Dhanak M. et al. , Retour Club des Argonautes - Dossier Energie Thermique des Mers ;“Evaluation of the sinks and sources of atmospheric CO2 by artificial upwelling”, Pan Y., Fan W. et al.;“Mitigating almost 1.5° C of global warming using OTEC-induced artificial ocean upwelling”, Miller A.F.; “Using oceanic forced upwelling and downwelling to mitigate rapid climate change in the North Atlantic", Kith i I P.W., Atmocean, Inc. Santa Fe); - thirdly, a prevention of storms or their intensitv/frequencv and/or a change in their place of occurrence and/or route. To this regard, one has to remember that one of the conditions for storm formation is a temperature of surface water higher than 26.5 degrees, whereas in the areas in which the artificial upwelling is caused, not only such temperature can never be reached, but the determined temperature is considerably lower than such value, considering that below 300 metres of depth the temperature of marine water is already lower than 15 degrees: at 500 meters it is about 10 degrees. As TO DOWNWELLING

Even the downwelling of surface water can contribute to cool down the surface layers of marine water: however, in this case, differently from what happens for the upwelling, such cooling-down follows the removal, by downwelling, of hotter surface water. The fact that the downwelling, apart from involving the cooling-down as above said, allows to eliminate water by now saturated with

CO2, and, consequently, to increase the capability of absorbing the same gas by underlying water, is particularly important.

As TO COMPRESSED AIR PRODUCTION

The particularly precious value of this type of energy is given by the fact that it is clean energy, which can be stored and easily transferred. Moreover, the compressed air produced with a hydraulic compressor is dry; without contaminants; it can be produced substantially without any additional cost, at any pressure value allowed by the morphological features of the marine environment in which the system is installed; the related process even involves the concomitant oxygenation of the water which made the compression.

As TO THE USE IN OTEC PLANTS

Although the performance of such plants is low - considering the not big difference in temperature between hot water and cold water used in the process (generally, not higher than 20 degrees) - it has to be considered that the electricity produced by such plants comes from a free, clean, inexhaustible, renewable resource and that the use of the pump, the present invention relates to, in such plants implements, as said, an additional result with respect to those highlighted in the points above.

State of art

As to artificial upwelling The devices which have been invented to cause an artificial upwelling are innumerable.

Then, one has thought to use the differences in density, temperature, salinity between surface water and deep water, the wave oscillatory motion, the energy of currents, hybrid systems using solar, chemical, wind, etc. energy.

A quite complete summary of the several technologies can be read in “Research progress in artificial upwelling and its potential environmental effects”, Pan Y., Fan W. et al. , in Science China Earth Science, 2015; “Feasibility analysis and trial of air-lift artificial upwelling powered by hybrid energy systerrf, Yang J., Zhang D. et al., in Ocean Engineering, 2017, pages 520-528; as well as in “Artificial upwelling using offshore wind energy for mariculture applications”, Pelegri J.L. and Vaque D., Planet Ocean, Scientia Marina, September 2016, pages 235-248;“Development of air-lifted artificial upwelling powered by wave”, Chen J. W., Yang J, et al., in MTS/IEEE Oceans Conference, Sep 23-27, 2013. San Diego 1-7.

Currently, the system which is considered to be most effective is the one based upon the pumping of deep water with the airlift system.

Such system can be summarized as follows: a long tube (upwelling pipe) is dipped vertically in water; the lower end is placed at the depth (usually, at least 300 metres) thereat there is the water which one wants to lift; the upper end - acting as discharge outlet - is placed at the height (or in proximity) of the sea surface. Into the upper section of the pipe, at a depth of at least 5/10 metres, through a suitable diffusor, compressed air is blown which, by mixing with the water existing in such tube section, decreases the density thereof. As a result, a pressure change is created between the column of air-water mixture existing inside the pipe and the corresponding water column outside the same, in consequence of which the reascending starts - and it continues for the whole time in which compressed air continues to be blown - inside the upwelling pipe of deep water and the discharge of the same from the discharge outlet.

The compressed air necessary to the airlift operation is produced by a specific compressor, driven electrically or fed with fossil fuels, installed, if possible, on the ground, or on barges, or floating platforms. One has also thought to use piston compressors, connected to floating devices, driven by waves’ energy.

The limit of this type of compressors mainly is given by the fact that the pumps operate through moving mechanical elements and that the quantity of compressed air which can be obtained through the wave is linked to the pump size features, which are inevitably limited. Moreover, a mechanical pump working in marine environment can easily be subjected to corrosion phenomena, wear and frequent failures.

Since the compressed air necessary to the airlift operation can have a not high compression value (an increase in pressure with respect to the atmospheric pressure even only of 0.2/0.3 atmospheres is sufficient), one has thought to input in the upper section of the upwelling pipe the compressed air produced by an OWC connected to the same by means of a hose.

A system of this type - studied and proposed already in 1976 by Me Cornick - is well described by Liang, N.K. (see “A Preliminary Study on Air-lift Artificial Upwelling System", Liang, N.K., 1996. Acta Oceanogr, Taiwan, pages 187-200).

The great advantage of this type of plant, with respect to those using mechanical compressors, is firstly given by the fact that the plunger which is used to compress air is a hydraulic plunger, which allows to overcome all disadvantages and critical issues faced by any type of mechanical pump which has to work immersed in sea environment.

Moreover, the use of a hydraulic plunger allows to use OWC having big sizes (with the unique limit set by the features of the wave occurring in the installation site) and then to produce huge volumes of compressed air. Against these advantages, however, there is still the great limit deriving from the fact that the plant is formed by three distinct components (a hollow body OWC, the upwelling pipe and a hose which transfers to the same the compressed air coming from the hollow body), installed in open sea, each one thereof is subjected to different forces (OWC and the upwelling pipe, to the forces of waves hitting them, respectively; the tube supplying compressed air, to the forces exerted by the motion of the hollow body, of the upwelling pipe and by the water in which it is immersed), which makes necessary, as to the hollow body and the upwelling pipe, the presence of distinct anchoring systems and, as to the tube for supplying compressed air, systems for fastening said pipe to the OWC and to the upwelling pipe. Moreover, suitable devices are required allowing the three components, notwithstanding the waves’ motion, to keep substantially unchanged their mutual position.

Moreover, in all plants of this type, the hollow body OWC, in order to operate, uses at least a mechanical valve allowing, in the suction phase, the atmospheric air to enter the interior of the hollow body, in the compression phase, the compressed air to outflow only inside the (upper) portion of the upwelling pipe, acting as emulsion tube.

The above features make the plant to be subjected to wear and risks of rupture and, however, force frequent checks, operating control procedures, maintenance procedures.

The above critical issues - which have strongly limited the development of this technology in favour of other systems - are instead overcome by the pump, the present invention relates to, which as said consists of only two structural components, a hollow body and a tube, both joined together so as to form one single body, and it has no moving mechanical parts.

As to downwelling In general cases, the forced downwelling (as well as the artificial upwelling) are performed in OTEC plants to have available hot water (and cold water) necessary to the plant operation. To this purpose, usually mechanical pumps are used. ln the limited cases in which, on the contrary, the aim which is pursued has only environmental nature (attempt at reducing global warming; preventing the formation of storms; downwelling huge quantities of C02), the downwelling generally is determined by harnessing the wave energy and in particular the potential energy deriving from the height of the same. To this purpose, the water forming the wave crest substantially flows by overtopping, and is collected inside floating vessels - the edges thereof are placed at higher height than that of the surface of sea when it is calm, but lower than that reached by the wave crest when the sea is rough - therefrom, through a suitable pipe, then, it flows out to the bed, by gravity.

The patent US20090173386 A1 by Jeffrey A. et al. , in its essential core, is based upon this principle.

The fundamental limit of such type of plants is substantially given by the fact that, on one side, only gravitational, and not kinetic, potential energy of waves can be used, on the other side, that only the wave limited portion raising beyond the hollow body’s edge can be captured.

These limits, as it will be seen, are instead overcome by the pump the present invention relates to.

As to compressed air production. The compressed air production by means of a hydraulic hydro-compressor - also designated trompe or Taylor compressor, or even HAC ( Hydraulic Air Compressor) is a century-long known art (to say the truth, as from antiquity) widely used in past, in particular in mines, to produce the compressed air necessary for cooling the tunnels placed at great depth and to guarantee the air change; in works (above all, in France and Switzerland) for constructing mountain tunnels, to actuate the hammers and other pneumatic devices used in excavation works; in Catalan furnaces, to supply combustion with strong jets of compressed air, with the purpose of reaching the high temperatures required for metal melting; in transportation and other fields.

Currently, its use has been proposed again, both to harness the modest water jumps, with the purpose of producing the compressed air necessary to drive air turbines (see“Performance Analysis of Low Head Hydraulic Air Compressor”, Salama Abdel-Hady . et al. , Smart Grid and

Renewable Energy, 2010, 1 , 15-24; Hydraulic air pumps for low-head hydropower”, Howey D.A. e Pullen K.R.; “Low-head hydroelectric power using pneumatic conversion, Bellamy N.W., in Power Engineering Journal, 1989”), and, more generally, as more reliable, effective, cheap, not polluting way, with respect to the current production technologies, of compressed air (see“Mechanical Efficiency of hydraulic air compressor”, Pavese V., Millar D. e Verda V. , in Journal of Energy Resources Technology 2016; Hydraulic Air Compressor (HAC) Demonstrator Project”, Millar d. e Muller E., ACE EE Summer Study on Energy Efficiency in Industry 2017).

The pumps of this type substantially consist of two tubes and by a chamber/tank, wherein the separation of compressed air from water takes place; they have no moving mechanical parts; once started, they operate continuously in time without the need for either adjustment or maintenance. For this reason, such pump type is particularly robust and substantially not subjected to failures nor wear.

Its performance is particularly high, higher than the one of any other type of existing compressor (it can reach, and even exceed, 80%), both because, as said, such compressor has no moving mechanical parts, and because the air compression takes place in strict contact with water flowing out in the motor tube, therefore it can be considered substantially isothermal.

The implementation and installation cost of the plant - if no particular drilling works and/or ground improvement works and/or construction work activities have to be made - is not high, also considering that the amortization may extend for the whole life cycle of the plant itself, which, to a considerable extent, coincides with the duration of the materials thereof it is made.

Nevertheless, the hydraulic compressor in reality has not developed greatly on industrial scale, since its installation in terrestrial environment (the only one in which one has thought to implement it), in order to produce significant volumes of air compressed at compression values adapted to market requirements (generally 7 or more atmospheres), depends upon the contemporary presence of three environmental conditions very difficult to be found:

1. a water course therefrom flows of several cubic metres per second can be derived

2. a water jump of at least 5 metres (but, preferably 10/15) between the water level supplying the motor tube of the hydraulic compressor and the one thereat the water used in the process is discharged outside;

3. a shape of the ground, where the intake structure is situated, allowing, without the need for particular excavation works, ground moving works and implementation of construction work activities, the installation of the hydraulic compressor motor tube in vertical position, with the discharge outlet at a depth adequately higher than that of the water column having height corresponding to the pressure value thereat air is to be compressed (and that is the water column which, by reascending inside the discharge tube, outflows then in the outer environment), as well as the construction and installation at such depth (which, for example for the production of compressed air at 8 atmospheres is about 90/95 metres) of the separation chamber of the air compressed by water.

All these limitations, instead, no longer apply in case the pump is installed in deep marine or lake environment, by creating an artificial jump between the column of water mixed with air flowing into the hydraulic compressor’s motor tube and the environment in which the same is discharged. In the hydraulic compressor according to the patent n. W02016/046689A1 - which is wholly immersed in sea water - such artificial jump is obtained by harnessing the energy of sea currents, by forcing the current water to cross, thanks to the kinetic energy of the same, if strong enough, that is even thanks to the push provided thereto by a pump driven by the current itself, a very big Venturi tube and by making the water, which made the compression inside the restricted section of said Venturi tube, to be discharged.

The fundamental limit of this type of hydraulic compressor, however, is given by the low yield of the suction system and by the consequent need, since significant volumes of compressed air to be assigned to the market are to be produced, for installing Venturi tubes having extremely big sizes, involving implementation and installation costs so as to reduce drastically the advantages connected to the high yield of the hydraulic compressor and to the advantages connected to the use of free and clean energy.

In the patent n. US3754147A, relating to a plant implemented in sea environment too, the hydraulic compressor instead is not wholly immersed. The intake mouth of the motor tube acting as compressor, in fact, is placed at a higher height than that of the free surface of sea when it is calm, but slightly lower than the one that, usually, is reached by the wave crest, when the sea is rough so that the pressure change which is used is the one corresponding to such height difference, which as it is acknowledged in the same patent, usually is in the order of only 1 - 1.5 metres and then substantially insufficient to produce remarkable amounts of air compressed at high compression values.

To this regard, in fact, it is to be considered that since in the motor tube in which the compression takes place there is not only water but even air, the pressure of the related column depends upon the density of the mixture existing in the same, therefore the higher the air percentage is, the lower the pressure will be.

Then, for example, if in a 80-metre-high pipe, the overall percentage of the air in the mixture is equal to 10%, the hydrostatic pressure which can be exerted by such column is equal (at most) to 72 metres of water column. This fact makes clear that the water jump necessary so that the plant may operate should be at least 10 metres.

Advantages of the invention

In all fields in which it can operate, the marine pump, the present invention relates to, has particularly important advantages with respect to the existing machines, deriving from:

1. firstly, its construction and operating features. In fact, the pump, as seen, is a machine without moving mechanical parts, it is made up of only two structural components, both joined together to form a single body; it is a simple and robust structure. Moreover, once installed, it operates automatically and indefinitely in time, without requiring particular start, adjustment, control and maintenance procedures. Its duration substantially coincides with that of the materials used for its construction;

2. extremely low cost. In fact, as far as the plant implementation cost is concerned, it substantially coincides with that of the materials used for the two structural components, the hollow body and the delivery tube, and for the anchoring system, since the costs for assembling the several components actually are irrelevant; as to the operating cost, it is substantially inexistent. Moreover, it can be amortized in an extremely long period of time;

3. its wide use possibilities. The pump, in fact, can operate effectively even discontinuously and by using waves having various (even if very limited) height, which allows to install the plant practically in any sea area;

4. particularly high yield, in particular as to the production of compressed air, since the production of the same through a flowing water column hydraulic compressor, as it is known, may provide yields near to or even higher than 80%;

5. substantial absence of environmental impact. The pump, in fact, usually is installed in open sea and even in the event that it is used to supply deep water to coast fish farming plants or for the production of compressed air, to be used on the ground, it is always installed at considerable distance (even kilometres) away from the coast and cold water and compressed air are transferred to the place of use through submerged pipe.

Description of the basic form of the invention

As already said, the pump, in its basic form, consists of only two structural components, both joined together to form a single body:

- a hollow body, provided with devices adapted to make it floating, with shape substantially analogous to that of a mushroom whose cap and stem are hollow, provided with anchoring devices which do not allow it to raise over the free surface of the sea when it is calm; which operates, in the spaced closed by the cap, like an oscillating water column (OWC), to compress the atmospheric air flowing inside thereof through suitable devices, in the one closed by the stem, like the emulsion tube of an airlift supplied by the compressed air indeed produced by the compressor;

- a tube, coaxial to the stem, acting in its lower section as delivery tube in the emulsion tube of the water to be raised; in the upper section, as conduit for supplying compressed air inside the same emulsion tube.

More in particular, the pump, in its basic form, which is the one according to claim 1 , substantially comprises the following structural/functional components:

1.1 ) a hollow body (TABLE 1 , lett. A+B). The same, as said, has a shape substantially analogous to that of a mushroom, the cap (TABLE 1 , lett. A) and stem (TABLE 1 , lett. B) thereof are hollow and the latter is open at its two ends. It is provided with devices adapted to make it floating.

The hollow body portion corresponding to the cap (TABLE 1 , lett. A), encompasses an air chamber and acts as compressor (hereinafter: compressor). Its shape, preferably, is so that its volume, in the portion which under calm sea conditions is above the floating line, increases with increasing height less than proportionally. The hollow body is as high as about the significant height of the waves occurring locally; it is immersed, under calm sea conditions, at a depth ranging from one third/one fourth of its overall height; its base is open; its side surface, along a strip of about 5-10 cm above the floating line, is crossed by several holes (TABLE 1 , lett. C), allowing the atmospheric air, when the wave lowers to descend below the sea level under calm conditions, to flow inside the hollow body and the water existing in the portion of the same acting as compressor to go out in the outer environment.

On the contrary, in the compression phase, the air cannot go out of these holes as the same result to be immersed as a consequence of the water level raising, caused by the wave, both inside the compressor and, to an even greater extent, outside. Such hollow body portion, preferably at the height of the floating line, is provided with handles (TABLE 1 , lett. D), or other devices, at least three, for hooking anchoring chains, so that it cannot lift above the free surface of the sea when it is calm. This latter feature involves that, when the sea is moved by waves, each wave passage determines inside the compressor the water raising depending upon the features of the wave itself; such raising, acting as hydraulic plunger, in turn determines the compression of the air contained in the hollow body.

The hollow body portion corresponding to the stem (TABLE 1 , lett. B) too is hollow and it acts like the emulsion tube of an airlift (hereinafter: emulsion tube). It is configured like a rectilinear tube section; made of stiff material; open at the two ends; immersed in vertical position in the sea water for a length of at least 12 metres. Its surface, starting from about 20/30 cm below the free surface of the sea when it is calm, is crossed by several holes

(TABLE lett. E), having size which increases gradually with increasing depth. The main goal of such holes is to allow, in the compression phase, the inflow of compressed air inside the emulsion tube, in the suction phase, the inflow of atmospheric air inside the compressor. Such constructive particular feature, as well as that constituted by the presence of holes on the side strip of the compressor surface above the floating line, makes not necessary to install specific mechanical valves, as instead it happens in most OWC plants. The upper end of the emulsion tube, after having crossed the compressor roof, stops at its height or just above it;

1.2) a delivery tube (TABLE 1 , lett. F). Such tube has a double function: in its lower section, it constitutes the tube conveying the water to be lifted inside the emulsion tube; in the upper section, it constitutes the outer wall of the conduit for supplying compressed air and for intaking the atmospheric air, according to subsequent point 1.3). It is constituted by a tube section made of stiff material, open at the two ends, integral to the hollow body; coaxial to the emulsion tube; having diameter slightly larger than the same. This involves that between the hollow body portion acting as emulsion tube and the delivery tube an air gap is created. The upper end of the delivery tube is positioned at a height of 5-10 centimetres below the hollow body roof - height usually not reached by the wave - so that, generally, in the compression phase, only air accesses the interior of the above air gap. Its lower end (TABLE 1 , lett. Fi) is positioned at a depth slightly higher than the one thereat there is the lower end of the emulsion tube and it is equipped with a grid, preventing foreign bodies from flowing inside pipes;

1.3) a conduit for supplying compressed air to the emulsion tube e for intaking atmospheric air to the hollow body (hereinafter: supply/suction conduit). Differently from most plants using the airlift pumping system, wherein the compressed air is transferred to the airlift through a specific tube connecting the compressor to the airlift, in the pump, the present invention relates to, thanks to the particular shape of the hollow body and of the delivery tube, a suitable tube is not necessary, but the supply takes place through the circular crown-sectioned tube formed by the air gap between the delivery tube and the emulsion tube (TABLE 1 , lett. G). Under calm sea conditions, such conduit is filled up with sea water as far as the height of the floating line of the hollow body, with air, in the overlying portion;

1.4) a diffuser. Such pump component is constituted by the set of holes existing in the emulsion tube (TABLE 1 , lett. E); therethrough, as said previously, the compressed air can spread inside the emulsion tube and the atmospheric air can flow inside the supply/suction conduit, according to the previous point and then inside the hollow body;

1.5) a series of devices or structural elements, allowing to join together several components of the plant, so as to form one single body;

1.6) an anchoring system. The same is constituted by at least three robust chains (TABLE 1 , lett. H), the upper ends thereof are hooked to the hollow body, the lower ones are fastened to the seabed, with heavy anchors or other systems. The push received by the hollow body towards the other one at each wave passage, in fact, is very strong. Therefore, for example, in case the hollow body- as the one according to TABLE 1 (illustrated, in detail, in the following chapter) has a 6-metre-wide cylindrical base and the air compression caused by the wave raising is about 0.5 atmospheres, the upward push received by the hollow body will be higher than 14 tons. The chains’ length substantially coincides with the existing distance, when the sea is calm, between the seabed and the hooking devices lying on the hollow body, which then cannot be lifted above the free surface of the same when it is calm.

Description of the drawing of one of the modes for implementing the pump basic form

TABLE 1 represents, in section, one of the several modes for implementing the pump basic form. The sea conditions thereto the table relates are calm sea conditions. One has preferred to highlight graphically the several pump components rather than meeting the proportions between the several elements of figure and environment, therefore it does not result to be a scale drawing. Moreover, even the measurements which in the present description are assigned to the several pump components are purely indicative and act only by way of example of the operating principle. In this table, the compressor (and, that is, the

hollow body portion performing such function) is designated by letter A; the same has cylindrical shape as far as little less than half of its height, truncated conical in the remaining portion. The compressor overall height is 1 metre and a half; the lower base diameter is 6 metres; the upper base diameter is 3 metres.

The compressor is immersed in water by 50 centimetres; its base is open, so that the water can penetrate freely the interior thereof. The compressor cylindrical portion height above the floating line is 20 centimetres; in the first 10 centimetres, the compressor wall is holed. The holes are designated by letter C. The compressor truncated conical portion height is 80 centimetres. In the drawing, letter D further designates two of the three handles constituting the points for hooking the anchoring chains; letter H designates the latter; on the contrary, the body of the devices guaranteeing the hollow body floating has not been represented in order not to prevent the holes, crossing along the strip of 5/10 cm the compressor wall, from being seen.

The emulsion tube is designated by letter B and it is represented like a cylindrical tube, open at the two ends. Its upper end outgoes by some centimetres from the compressor roof. The emulsion tube has a 1 -meter-wide diameter; its length is 14 metres; it is immersed in vertical position by 13 metres. In the table, the holes are highlighted which, starting from about 20/30 centimetres below the free surface of the sea when it is calm, are present on its side surface; their size increases with increasing depth. Such holes are designated by letter E.

The delivery tube is detected by letter F. Letter Fi designates the lower end of the delivery tube, acting as intake mouth, and which is at a depth of 13.50 metres (slightly lower than the one thereat there is the lower end of the emulsion tube).

The hollow body volume which, when the sea is calm, is occupied by atmospheric air, is equal to about 18 cubic meters, cubic metres, about 5.50 thereof constitute the volume occupied in the cylindrical portion and 12.50 constitute the truncated conical portion.

Operation principle

The operation principle can be summarized as follows:

1) When the sea is calm:

1.1 ) the hollow body floats at the height of its surface; the outer atmospheric air can freely flow inside thereof through the holes existing in the lower portion of its side surface, by occupying the whole space existing above the water free surface;

1.2) the whole water existing inside the compressor, in the supply/suction conduit, in the emulsion tube and outside the hollow body is at the same level and it is subjected to the atmospheric pressure.

2) When the sea surface is moved by waves and the wave raises:

2.1 ) the hollow body can oscillate vertically only in the space comprised between the wave trough and the sea level when the sea is calm, since, once reached such height, the anchoring system locks it;

2.2) the wave, in turn, when the hollow body stops:

2.2.1 ) continues to lift and to expand freely - as it does not find obstacles - in the space outside the hollow body, which consequently results to be immersed by a height equal to half height of the wave;

2.2.2) on the contrary it cannot do the same thing in the hollow body space encompassing the air chamber (and, that is, in the compressor), as it meets resistance in the herein existing air. In fact, once the wave penetrated the hollow body has exceeded the height of the holed strip existing on the side surface of the same, the air can no longer exit the compressor, so that any additional raising of the water level inside the same involves - until air starts to flow inside the emulsion tube - a decrease in the space occupied by air and the consequent progressive increase in the pressure of the same, proportional to the decrease in the occupied volume;

2.2.3) the height thereat the water can penetrate the hollow body interior substantially depends upon the shape and volume of the hollow body above the floating line, as well as upon the wave height and kinetic energy, intended to transform into pressure energy as the air existing in the hollow body, by increasing in pressure, gradually opposes increasing resistance, until stopping it. Such height is given by the point in which the air pressure included in the hollow body is equal to the one exerted by the wave that has penetrated the interior thereof;

2.2.4) the same does not take place as to the water existing in the supply/suction conduit and in the emulsion tube. In fact, since the intake mouth of the delivery tube - therethrough the sea water flows inside the emulsion tube - is placed at a depth of about 13 metres, thereat the wave energy is almost negligible, water can raise inside said tubes only (substantially) depending upon the hydrostatic pressure exerted at such water depth. Moreover, the height thereat the water level raises in the supply/suction conduit and in the emulsion tube is not the same, since the water existing in the emulsion tube is subjected to the atmospheric pressure, the one existing in the supply conduit to the pressure of air existing in the hollow body. This involves that, as the pressure of the air existing in the hollow body gradually increases, a difference in pressure is created between the water existing in the supply/suction conduit and the one contained in the emulsion tube, as a consequence of which:

- the water existing in the supply/suction conduit is forced to descend downwards and to flow inside the emulsion tube through the holes existing on the same; - the compressed air flows inside the emulsion tube and, by mixing with herein existing water, allows such tube to operate as an ordinary airlift.

3) When the wave phase is decreasing:

3.1 ) the water level both outside and inside the hollow body lowers and the water contained in the compressor can even come out from the holes existing in the side wall of the hollow body;

3.2) furthermore, since a portion of the air existing originally inside the hollow body has come out of the same in the compression phase, to flow inside the emulsion tube, the water level lowering inside the compressor determines a depression condition, in consequence of which the atmospheric air flows inside the compressor both through the holes existing in the side strip of the same and through those existing in the emulsion tube.

4) For the sole purpose of rough evaluation about the pump capability, hereinafter one provides the calculation, by pure way of example, of the pressure which can be obtained inside the pump according to TABLE 1 , in the actuating mode and with the previously mentioned measurements, in case the water raising inside the compressor, consequent to the wave passage, is 20 cm. The calculation is performed without considering the fact that, when the air pressure exceeds the (low) hydrostatic pressure exerted by the water column overlaying the first holes (lower than 0.1 atmospheres), the process for flowing atmospheric air into the emulsion tube is started.

As seen, the hollow body volume which, under calm sea conditions, is occupied by the atmospheric air is equal to about 18 cubic metres, about 5.50 thereof constitute the cylindrical portion volume and 12.50 the truncated conical portion volume.

The water level raising of 20 cm forces the air to occupy only the volume delimited by the truncated conical portion of the hollow body, with a volumetric reduction of about 30% and a corresponding air pressure increase of about 4.5 metres, in terms of equivalent water column.

A pressure increase of this extent allows, in a plant having the mentioned sized, the upwelling of several cubic metres of water per second, provided that: -the water quantity which is possible to upwell in the unit time (substantially) depends, on one side upon the emulsion tube diameter, on the other side upon the pressure difference which is possible to be determined between the mixture column existing in the same and the corresponding water column placed outside;

- with a pressure of about 1.4 atm, that is equal to about 14.8 metres of water column, if the air-water mixture which is created is by 50%, the column of the same which is possible to supply inside the emulsion tube can reach a height of about 8 metres, corresponding to a 4-metre column of only water, so that if the discharge outlet of the emulsion tube is placed at the height, as in the described plant, of 1 metre above the sea level, at the height of the same, still considering the pressure drops, a pressure change of about 3 metres will be available, which allows to lift, still by making reference to a 50% air-water mixture, a flow of about 2/3 cubic metres of (only) water per second.

Variants of the basic forms and pump versions

As said, the pump illustrated in the previous point is the one related to its basic form and that is the one which substantially exists in all four versions of the same. Such form, moreover, provides different variants which can relate to both the single components of the pump (compressor, emulsion tube, delivery tube, conduit for supplying compressed air, diffusor), and the immersion depth of the hollow body, and the anchoring system, which in some variants can allow the hollow body to oscillate completely depending upon the wave course, in other variants it can impede it completely.

Such variants can be present in all pump versions or only in some thereof. Hereinafter both the variants of the basic form of the pump and the single versions of the same with, if existing, the related variants are illustrated hereinafter.

A) Variants of the basic form

The variants of the pump basic form provided in the present patent application are 6 and may be briefly described as follows:

A.1) Variant n.1 (set forth by claim n. 2) It relates to the delivery tube and the conduit for supplying compressed air. In this variant:

A.1.1) the delivery tube is very short, less than one meter, it has the same diameter as the emulsion tube; it is joined physically to the same, so that the two tubes, even if they continue to have a separate function, constitute one single lifting tube (TABLE 2, lett. I);

A.1.2) the conduit for supplying compressed air is constituted by a tube having circular crown section formed by the air gap (TABLE 2, lett. G) between the emulsion tube and another tube coaxial to the latter (TABLE 2, lett. L) and having a slightly larger diameter than the same, the lower end thereof is closed and it is placed at the depth thereat the emulsion tube joins together with the delivery tube; the upper end is positioned at a height of about 5/10 centimetres below the hollow body roof. In this variant, the operating principle is substantially identical to the one described for the basic form.

A.2) Variant n.2 (set forth by claim n. 3)

It relates to the lifting tube and the conduit for supplying compressed air. In this variant:

A.2.1) the lifting tube (TABLE 3, lett. I), even in the section acting as emulsion tube, has no holes;

A.2.2) the conduit for supplying compressed air is constituted not by the tube having circular crown section described at point A.1.2. (with reference to the first version), but by a tube (TABLE 3, lett. M), open at the two ends, that is only in the upper end; its diameter is considerably smaller than the one of the emulsion tube; internal and usually coaxial to the same for almost its entire extension; the surface thereof, starting from few decimetres below the free surface of the sea when it is calm, is crossed by several holes (TABLE 3, lett. E), having sizes increasing with increasing depth; the upper ending section thereof, after having crossed the emulsion tube, stops at a height of few decimetres below the hollow body roof. Even in this variant, the operating principle is substantially identical to the one described for the basic form, except the mode for inletting compressed air, which takes place in the central portion of the emulsion tube.

A.3) Variant n. 3 (set forth by claim n. 12)

It relates to the anchoring system or even the same shape/structure of the hollow body with reference to such profile. In this variant, the hollow body is not provided with devices adapted to make it floating, but it is joined, firmly, to a basement fastened to the seabed, or to other structure (for example, a wholly submerged floating platform, anchored to the seabed), forcing to keep substantially unaltered its own position despite the waves’ motion.

According to this variant the hollow body can consist even of a fixed structure (usually made of concrete or steel), incorporated in the coast, acting as compression chamber of an OWC. In the latter case, the pump is electively used to lift (preferably, by subsequent stages, according to claim n. 9) the water present in the compression chamber to supply it the potential energy required to actuate a hydraulic machine (for example a turbine).

A.4) Variant n. 4 (set forth by claim n. 13)

It relates to the compressor. In this variant, the compressor is divided vertically into sectors for about two thirds of its height by one or more walls inside the same.

The presence of septa may allow, depending upon the ratio between the compressor base surface and the features of wave, a greater effectiveness in transforming the kinetic energy of the same in pressure energy.

A.5) Variant n. 5 (set forth by claim n. 14)

It relates to the compressor, the compressor immersion depth and the anchoring system. In this variant, the compressor has a higher height than the one of the significant wave occurring locally and it is immersed in water by more than half of its height. It is not provided with devices adapted to make it floating, but as in variant A.3), the anchoring system forces it to keep unaltered its own position despite the waves’ motion. The operating principle, as far as air compression is concerned, is the one described by McCormick in “Ocean Wave Energy Conversion”, Dover Publications, 2007, pages 61 -66.

A.6) Variant n. 6 (set forth by claim n. 15)

It relates to the compressor, the immersion depth of the same, the emulsion tube or the tube for supplying compressed air and the anchoring system. In this variant:

A.6.1) the compressor has a higher height than the one of the significant wave occurring locally and it is immersed in water by half of its height, as in the variant according to the preceding point A.5);

A.6.2) the side surface of the hollow body has no holes;

A.6.3) the section of the emulsion tube, that is of the tube for supplying compressed air in case of variant according to the preceding point A.2), the surface thereof is holed, starts as from few decimetres above the free surface of the sea when it is calm;

A.6.4) the system for anchoring the plant to the seabed and/or in case to other fixed structure allows the hollow body to oscillate by following the waves’ motion.

The operating principle, as far as air compression is concerned in particular, is the one described by McCormick (op. cit. pages 66-71 ).

In this variant, the fact that the hollow body can oscillate by following the whole motion of the wings involves that, in the compression phase, the presence of holes on the side strip of the compressor could allow compressed air to be discharged, which fact suggests to remove them. Moreover, due to the difference in vertical speed between the compressor and the water column contained therein, in the compression phase, the section of emulsion tube which results to be submerged is larger than the one submerged under calm sea conditions, which fact makes suitable that the holed surface of the emulsion tube that is of the tube for supplying compressed air starts at few decimetres above the free surface of the sea when it is calm.

B) Pump versions As it is said, the pump can be implemented substantially in four versions:

B1) in one version, for the upwelling at the sea surface level of cold and deep marine water ( artificial upwelling) · ,

B.2) in a second version, for the lifting and transfer of this water to the place of use, even if kilometres away;

B.3) in a third version, for the downwelling of the surface sea water ( forced downwelling) · ,

B.4) in a fourth version, for the downwelling of surface water, its oxygenation and the simultaneous production of compressed air, without significant additional energy costs.

The above pump versions can be described as follows:

B.1) Version for the upwelling of deep water

B.1.1 ) In this version (set forth by claim.4), the intake mouth of the delivery tube is joined to a hose - an upwelling pipe - along several hundreds of metres or even more, the lower end thereof, acting as intake mouth, is placed at the depth thereat there is the water which one wants to lift, which can come from even very far sites with respect to the point in which there is the pump.

This is particularly useful in case the pump is used to provide cold, deep water, rich of nutrients, to fish farming plants placed along the coast or however in places wherein the sea is shallow. It is to be highlighted that the pump effectiveness is not conditioned in particularly significant way by the depth of water to be lifted, since even if it is true that the density of deep water generally increases when the depth gradually increases and that longer lengths of upwelling pipe involve greater pressure drops, it is also true that the pressure change required for the circulation of such water is wholly low. This pump version provides a variant, which relates to the upwelling pipe.

B.1.2) In such variant (set forth by claim n.5), a buoy keeps the last 5-10 metres of the upper section of the upwelling pipe in horizontal position or however with an angle so that the vertical motion of the hollow body involves only this tract and not the whole pipe. B.2) Version for the upwelling of deep water and their transfer by gravity to the place of use.

This version (set forth by claim n. 6) is characterized by the following features:

B.2.1 ) the upper end of the emulsion tube does not stop at the height of the compressor roof, but it projects therefrom by few metres, leading into the interior of a recipient - usually, a tube having larger diameter, closed at the base - acting as tank for the collection and loading of the lifted water which has separated from emulsion;

B.2.2) the water which gradually flows into the loading tank is transferred to the place of use through a pipe, the upper end thereof, acting as intake mouth, leads into the interior of the tank, at the height of its base; the lower end, acting as discharge outlet, reaches the place in which the water has to be used and it is placed at a lower height than the one of the free surface of the water which is collected in the collection tank.

This version is particularly useful when, for landscape and environmental reasons, it is not possible or suitable to install the pump where deep water has to be used. It is just convenient to underline that even a low difference in level (for example, even by 2-3 metres), allows the transfer by gravity of water even at great distance.

B.3) Version for the downwelling of surface sea water ( forced downwelling).

B.3.1) This version (set forth by claim n.7), under different aspects, is similar to the one described at the previous point B.2). In fact, even in this version, the water which flows into the delivery tube is lifted by few metres above the sea level and then conveyed inside another tube, which transfers it somewhere else by gravity. In this version, the pump is constituted either by the one according to the basic form or by the one according to the variant A.1 ), except from the following features/difference:

B.3.1.1 ) the emulsion tube diameter, in case of the pump implemented according to the basic form, that is the lifting tube, in case of the pump according to variant A.1 ), is larger than that provided in said pumps; the upper end of the same projects from the compressor’s roof and it stops at a height higher by about one metre than the one thereat the air-water emulsion is lifted (TABLE 4, letters I and N, by considering that both such valve and the subsequent ones 5 and 6 illustrate pumps implemented according to the variant A.1 ), set forth by claim n. 2).

B.3.1.2) inside the emulsion tube, in case of claim n.1 , or the lifting tube, in case of claim 2, another tube is placed (TABLE 4, lett. 0) - acting as tube for discharging lifted surface water - coaxial to said tubes. Its diameter slightly exceeds half diameter of the latter; the upper end thereof - which acts as intake mouth for the water which has separated from emulsion - is placed at a lower height than the one thereat the emulsion is lifted; its lower end reaches the depth thereat the lifted water is to be discharged.

B.3.2) This pump version provides a variant (set forth by claim n.8), which relates to the supply of the delivery tube and it has the function of allowing the downwelling of the water placed immediately below the sea surface, which is the hottest water, richest in carbon dioxide. In this variant:

B.3.2.1 ) the intake mouth of the delivery tube (TABLE 5, lett. h) leads into the interior of another tube (TABLE 5, lett. P), thereto it is integrally joined, having more than double diameter, closed at the base, acting as tank for supplying the same, in which surface water flows since its upper end is placed at a slightly lower height than the one of the sea surface;

B.3.2.2) the discharge tube (TABLE 5, lett. O) crosses the base of said supply tank.

B.4) Version for the downwelling of surface water, the oxygenation of the same and the simultaneous production of compressed air.

B.4.1) This pump version (set forth by claim n. 10), is constituted by the one for the downwelling of surface water, described at the previous point B.3, in which:

B.4.1.1 ) the discharge tube is placed at the depth corresponding to the one thereat one wishes to compress the atmospheric air;

B.4.1.2) there are the following additional components: -a Venturi tube (TABLE 6, lett.Q), assembled on the upper end of the discharge tube (TABLE 6, lett. O-i), or just below it, the throttle ratio thereof is so that the water flowing out in its restricted section has a lower pressure than the atmospheric one;

- a suction conduit (TABLE 6, lett. R) or other device which allows the atmospheric air to flow inside the restricted section of Venturi tube to mix with water flowing therein;

- a bell (TABLE 6, lett. S), the interior thereof the lower end of the discharge pipe penetrates by few metres (TABLE 6, lett. O2), and in the upper portion thereof the compressed air is collected, as it gradually comes out from said pipe;

- a set of devices and/or structural elements allowing to the bell to be integral to the lower end of the discharge tube;

- a suitable tube (Table 6, lett. T), connecting fluidically the upper portion of the bell to the place of use/storage of the compressed air, provided, at the lower end thereof, with a float valve (Table 6, lett. U) or other closing device, disconnecting hydraulically such conduit from the bell when the water level inside the same reaches a predetermined height.

B.4.2) This pump version provides a variant (set forth by claim n.9) which relates to the lifting according to several subsequent stages of water to be used as working fluid for the hydraulic compressor, so as to provide to such fluid the piezometric load necessary to produce compressed air effectively. In fact, whereas for the downwelling of surface water it is sufficient a low piezometric load, in case one intends to exploit the downwelling process even for the production of compressed air, the piezometric change necessary to operate the hydraulic compressor is higher. In fact, the plant operation implies that the water column existing in the hydraulic compressor has an (adequately) higher pressure than the one exerted in the point outletting from the water column outside the pipe. So that a suitable piezometric load is implemented, however, it is not sufficient that the first column is higher than the second one, since in the first one (that is in the one of the hydraulic compressor), there is not only water but even air, in gradually decreasing volumetric percentages, sucked through Venturi tube.

This variant - which, moreover, does not relate exclusively to this pump version, but, as indicated in claim n. 9, it can be applied even with reference to the versions for the lifting of deep water and the transfer thereof by gravity to the place of use; to the one for the downwelling of surface sea water; as well as to any other form of use of lifted water - is characterized in that:

B.4.2.1 ) the upper end of the emulsion tube does not stop at the height of the hollow body roof but it projects therefrom by at least one metre, by leading into the interior of a recipient, usually a tube having larger diameter, closed at the base, acting as tank for collecting the lifted water which has separated from emulsion;

B.4.2.2) the water flowing into the tank is further lifted by one or more airlifts in series, supplied too by the compressed air produced by the compressor. B.4.3) Another variant of this pump version (set forth by claim n.11 ) is constituted by the fact that:

B.4.3.1 ) the length of the delivery tube, in the portion underlying the emulsion tube, according to claim n. 2, is (at least) 15/20 metres;

B.4.3.2) a small portion of the compressed air which is collected in the bell is made to flow through a suitable tube immediately above the lower end of the delivery tube which then is configured and acts too as emulsion tube, thus by allowing to lift the air-water mixture to a higher height.