aFIELD OF INVENTION

This invention relates to the unique and novel method of effectively utilizing the energy present in waves created by the ocean / sea for generation of electric power.

BACKGROUND

Electric power is normally generated in fossil fuel fired thermal power plant, Nuclear energy power Nuclear plant, using energy in water flow designated as hydro electric and through other chemical reaction etc.

The Archimedes' screw, also called the Archimedean screw or screw pump, is a machine historically used for transferring water from a low-lying body of water into irrigation ditches. The screw pump is commonly attributed to Archimedes on the occasion of his visit to Egypt, but this tradition may only reflect that the apparatus was unknown before Hellenistic times and introduced in his life-time by unknown Greek engineers.

The Archimedes' Screw consists of a screw (helical surface surrounding a central cylindrical shaft) inside a hollow pipe. The screw is turned usually by a windmill or by manual labor. As the bottom end of the tube turns, it scoops up a volume of water. This amount of water will slide up in the spiral tube as the shaft is turned, until it finally pours out from the top of the tube and feeds the irrigation systems. It was mostly used for draining water out of mines or other areas of low lying water.
The contact surface between the screw and the pipe does not need to be perfectly water-tight because of the relatively large amount of water being scooped at each turn with respect to the angular frequency and angular speed of the screw. Also, water leaking from the top section of the screw leaks into the previous one and so on, so a sort of mechanical equilibrium is achieved while using the machine, thus limiting a decrease in mechanical efficiency.

In some designs, the screw is fixed to the casing and they rotate together instead of the screw turning within a stationary casing. A screw could be sealed with pitch resin or some other adhesive to its casing, or, cast as a single piece in bronze, as some researchers have postulated as being the devices used to irrigate the Hanging Gardens of Babylon, one of the Seven Wonders of the Ancient World. Depictions of Greek and Roman water screws show the screws being powered by a human treading on the outer casing to turn the entire apparatus as one piece, which would require that the casing be rigidly attached to the screw.

A screw conveyor is an Archimedes' screw contained within a tube and turned by a motor so as to deliver material from one end of the conveyor to the other. It is particularly suitable for transport of granular materials such as plastic granules used in injection molding, and cereal grains. It may also be used to transport liquids. In industrial control applications the conveyor may be used as a rotary feeder or variable rate feeder to deliver a measured rate or quantity of material into a process.

Several variants of the Archimedes' screw are known but n=most of them function either manually or by electric motors. There is an urgent need for a self actuating Archimedes' screw which can be used in the generation of the electricity from the sea/ocean waves.

OBJECT OF THE INVENTION

The object of the present invention is to use the energy inherently present in the waves created by oceans and the sea to generate electric power.

Further object of the invention is to efficiently utilize the energy present in the waves that is being constantly created and flowing on to the beaches of the oceans and seas.

Further object of the invention is to provide an improved self actuating Archimedes Screw to raise seawater above mean sea level by harnessing wave energy.

Another object of the invention is to system and process for utilizing the wave energy of the sea/ocean to generate electric power.

SUMMARY OF THE INVENTION

In order to obviate the drawbacks of the prior art and to achieve the above-said objectives the present invention provides an improved self actuating Archimedes Screw to raise seawater above mean sea level by harnessing wave energy comprising:

- a hollow duct / tube of predetermined length and diameter;

- said hollow duct / tube having spiral fins of predetermined shape and size, fixed on the
outer side of said hollow duct;

- said hollow duct / tube having a tube of predetermined diameter coiled, wound and fixed on
the inside of the said hollow duct / tube.

wherein the design, size of the complete modified Archimedes Screw including the hollow duct / pipe; spiral fins; coiled tube will depend upon the height of the sea wave/tidal wave, frequency of the sea wave/tidal wave; distance from the land; other ocean current etc.

The waves include the sea waves and tidal waves.

Utilizing the energy inherently present in the waves that are constantly being generated in the oceans and seas and breaking on to the beaches, seawater can be raised to higher height to generate potential energy before being released as kinetic energy to rotate an electric power generator. With the help of a suitably designed Archimedes Screw, energy present in waves generated by the sea can be used to rotate the Archimedes Screw leading to lifting of the seawater itself from sea level to a much higher height. The potential energy now present in the pumped seawater can be suitably converted into kinetic energy to rotate an electric generator.

The invention further provides a system for utilizing the wave energy of the sea/ocean to generate electric power comprising:

- placing the modified Archimedes screw at a suitable angle with respect to the flow of the
incoming sea waves whereby said modified Archimedes screw will rotate by itself with ease
utilizing maximum energy available in the sea/tidal waves; and

- turbines connected with electric generator at the predetermined positions to receive the sea
water from the said modified Archimedes Screw to generate electricity.

The invention further provides a process for utilizing the wave energy of the sea/ocean to generate electric power comprising:

- allowing the waves of the sea / tidal waves of the ocean to pass over / through the modified Archimedes screw causing it to rotate thus raising the level of the sea water so as to convert the potential energy of the sea waves / tidal waves into the kinetic energy; and

- passing the sea water from the said the modified Archimedes screw into the turbines connected to the electricity generators to convert the kinetic energy now present in the raised seawater in to electric energy.

DESCRIPTION OF THE INVENTION

Figure 1: A typical Archimedes Screw.

Figure 2: A typical Archimedes Screw with flexible pipe wrapped around it to carry the water
from sea level to a high height.

Figure 3: Archimedes Screw of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Using the energy inherently present in these waves, seawater is raised to appropriate height so that the potential energy can be converted into kinetic energy and used to drive a suitable electric generator. A well designed and sized Archimedes Screw made out of suitable and appropriate material of construction is installed in an inclined manner along the coast / beach ensuring that the waves lashing on to the beach, rotates the Archimedes screw in the correct direction so as to pump the seawater to a higher height. Construction of the Archimedes screw can be such that there are continuous blades on the outside to make it rotate, while a pipe of suitable material of construction can be wound on the inner / outer shaft of the Archimedes screw to raise seawater from sea level to a higher height.

An Archimedes Screw made out of suitable and appropriate material of construction and designed to rotate using the energy present in the waves lashing on to our beaches is installed in such a manner that seawater is constantly pumped to a higher height than the sea level itself. Wind energy as well as solar energy can also be used to assist in the rotation of the Archimedes Screw and also for pumping the seawater to much more higher height. After raising the potential energy of the pumped seawater, it is released to be used as a kinetic energy to rotate an electric generator.

The seawater having been raised to a suitable height in one or two steps will now have sufficient potential energy that can be suitably converted into kinetic energy. If deemed necessary wind energy and / or solar energy can also be used directly or indirectly to raise the height of the pumped seawater thus raising its potential prior to conversion into kinetic energy which can be used for rotating electric power generator. The spent seawater devoid of potential and kinetic energy may be returned to the sea.

The present invention relates to the unique and novel method of effectively utilizing the energy present in waves created by the ocean / sea for generation of electric power. The invention efficiently utilizes (harness) the energy present in the waves that is being constantly created and flowing on to the beaches of oceans and seas. Using the enormous energy inherently present in the sea waves, seawater is raised to an appropriate height so that the potential energy can be converted into kinetic energy and used to drive a suitable electric generator.

With the help of a suitably designed Archimedes Screw, energy present in waves generated by the sea can be used to rotate the Archimedes Screw leading to lifting of the seawater itself from sea level to a much higher height. The potential energy now present in the pumped seawater can be suitably converted into kinetic energy to rotate an electric generator.

Archimedes Screw made out of suitable and appropriate material of construction (Plastics and / or Fiber Reinforced Plastic) to withstand the erosive and corrosive nature of seawater can be designed to rotate using the energy present in sea waves so as to lift the seawater itself to a height of say three meters. Wind energy as well as solar energy can also be used to assist in the rotation of yet another Archimedes Screw, or a pump, for pumping the seawater to much higher height. After raising the potential energy of the pumped seawater, it is released to be used as a kinetic energy to rotate a KAPLAN / FRANCIS type of turbine connected to an appropriate electrical generator.

The sea wave powered Archimedes Screw pump that will lift seawater to required height would have to be designed, manufactured / fabricated and installed in the Ocean Engineering laboratory of Indian Institute of Technology - Madras. Tests and trials would have to be carried out to estimate quantity of sea water that can be lifted to requisite height by the Archimedes Screw using Random Wave Flume.

According to the first embodiment of the present invention several appropriately designed & sized fins are fixed on the outside of the cylinder at suitable intervals, to assist in the rotation of the cylinder using wave energy. The Archimedes Screw is installed at an inclined position, while ensuring the bottom of the screw is always dipping into seawater and with each rotation of the screw, seawater should rise towards the top. Fine sand that may enter the screw will tend to fall back and leave the screw from the bottom. Couple of ball bearings to hold complete assembly in position as well as to allow free rotating motion is fixed on the outside of the cylinder in between the row of plastic fins.

According to second the embodiment of the present invention it is envisaged that the helical blades inside a typical Archimedes Screw are replaced with the cylinder serving as a base for a spiral shaped tube. Please refer diagram below. The cylinder as well as the flexible tubes is made out of plastic material to withstand seawater corrosion. As usual the cylinder is installed at an inclination. Several appropriately designed & sized fins are fixed on the outside of the cylinder at suitable intervals, to assist in the rotation of the cylinder using wave energy. With each rotation, seawater should rise in the flexible tube

The Archimedes screw of the present invention has the following construction:

1. The contraption is basically a hollow duct (1) of suitable length and diameter made out of FRP (Fiber Reinforced Plastic) or Polypropylene to withstand the corrosion and erosion nature of seawater.

2. Suitably designed and size, SPIRAL FINS (2) are protruding on the outside of the duct - to create the rotating motion when sea waves pass over it.

3. A plastic pipe (3) of appropriate diameter is suitably coiled, wound and fixed to the inside the hollow duct. This plastic pipe will carry the seawater with each rotation of the hollow duct.
The complete contraption is placed appropriately / suitably to the flow of the incoming sea wave. This will ensure that each wave will travel the full length of the hollow duct, with the spiral fins making the hollow duct rotate, due to the motion of the wave. This will also ensure that by the time the first wave reaches the other end of the hollow duct, another wave would have straddled the hollow duct from the front end - leading to an almost smooth, steady and continuous rotation of the hollow duct. In this position, the hollow duct will be facing the land, and will therefore be a shade easier to transport the seawater that has been raised to the required height on to the land for storage and subsequent rotation of a KAPLAN type turbine attached to a electric generator. Coil and Spiral Pumps These pumps use a similar principle to the Archimedean screw except that they run horizontally while the Archimedean screw is tilted at about 30°. The coil and spiral pump family, if fitted with a suitable rotating seal, can deliver water to a greater height, typically 5-10m, above their discharge opening.

In case the hollow duct is placed horizontal to the flow of the incoming sea wave, the rotation of the hollow duct will be intermittent and will have to depend upon the frequency of the sea waves for continuous rotation. The fins protruding on the outside of the hollow duct will be straight and not spiral. In this position the force of each sea wave will act on the full length of the proposed contraption.

In any case the contraption for lifting the sea water to a height of more than 5 meters above mean sea level has to be placed / anchored at a certain distance from the land - surely before the sea waves break to harness the maximum energy possible from the sea wave.

It is also being advocated that the design and size of the hollow pipe with its fins and plastic coiled pipe filled with seawater floats either partially or fully all by itself. Here again Archimedes principle will come to play. This will assist the contraption to adjust itself, for any minor or major change in the direction of incoming wave.

In order to harness maximum energy present in the sea waves, it has been contemplated that the modified 'Archimedes Screw' be installed at an inclination almost perpendicular to the motion of the sea wave and not parallel to it. In this position the sea wave would have to travel the full length of the 'Archimedes Screw'. With a helically formed fin on the outside of the modified 'Archimedes Screw', it is expected that the sea wave will keep rotating the 'Archimedes Screw' as it passes over it, until the sea wave breaks. In this position, there is also a possibility of two or more sea wave straddling and rotating the 'Archimedes Screw' one behind the other ensuring continuous rotation.
In this position, it is much easier to pump the sea water on to the land.

In this position, it is now also possible to install the electric power generation unit directly on to the modified 'Archimedes Screw', instead of pumping water.

The theoretical calculation of converting 'wave energy' into possible potential energy and / or kinetic energy:

With the following assumptions:

Average wave height is around 2.0 meters (amplitude)

Average wave period is 6 seconds (duration of a single wave)

P = 0.5 kW / m3.s (2.m)2 (6.s) = 12 kW / m

With P the wave energy flux per unit of wave-crest length

The Archimedes Screw length is 3 meters

The Archimedes Screw diameter (including fins screw on the outside): 1 meter

5 centimeter inner diameter plastic pipe; is wound inside the Archimedes Screw

The Archimedes screw is installed vertical to the flow of sea wave

Each sea wave will travel the full length of the Archimedes screw

At any given time one or more sea wave is rotating the Archimedes screw

Full Wave length is minimum 3 meters; and the seawater from the extreme end of each wave keep converging on to the Archimedes screw fins as they travel the full length of Archimedes screw - leading to maximum utilization of energy present in each sea wave

Sea Wave frequency is one wave per minute

It is estimated that:

P' wave energy flux per meter of wave crust length: 12 kW / m x 3 m = 36 kW
36 kW per sea wave x 60 waves per hour = 2160 kW per hour

Assume only 70% of this energy is utilized to lift seawater to an height of 5 meters by the

Archimedes screw

1500 KWH can lift 7500 cubic meters per hour of seawater to 5 meters height

Seawater passed through 'Kaplan' turbine connected to a generator: 60 KW of electric power
can be generated. (Based on details from Turbine supplier Pentaflo).

SALIENT FEATURES OF THE INVENTION

• The invention offers a significantly economic solution, for the generation of electric power using the inherent energy present in the naturally occuring seawater waves.

• The invention enables generation electric power with alternate source of energy consumption

• The invention enables easy, convenient and alternative method for tackling electric power scarcity in metropolitan and cosmopolitan cities.

• Further this process is environment friendly.

We claim:

1. An improved self actuating Archimedes Screw to raise seawater above mean sea level by
harnessing wave energy comprising:

- a hollow duct/tube of predetermined length and diameter;

- said hollow duct/tube having spiral fins of predetermined shape and size, fixed on the outer side of said hollow duct;

- said hollow duct / tube having a tube of predetermined diameter coiled, wound and fixed on the inside of the said hollow duct/tube.

wherein the design, size of the complete modified Archimedes Screw including the hollow duct/pipe; spiral fins; coiled tube will depend upon the height of the sea wave/tidal wave, frequency of the sea wave/tidal wave; distance from the land; other ocean current etc.

2. The self actuating/rotating modified Archimedes Screw as claimed in claim 1, wherein said screw is made of the Fiber Reinforced Plastic (FRP) or Polypropylene or any other suitable material of construction after taking into consideration the erosive and corrosive nature of seawater.

3. The self actuating/rotating modified Archimedes Screw as claimed in claim 1, wherein the length of the modified Archimedes screw depends up on the frequency of the sea wave / tidal wave.

4. The self actuating/rotating modified Archimedes Screw as claimed in claim 1, wherein the waves include the sea waves and tidal waves.

5. The self actuating/rotating modified Archimedes Screw as claimed in claim 1, wherein rotation of the modified Archimedes screw, causes seawater to rise in the coiled tube attached to the modified Archimedes Screw thus raising the level of the sea water to a higher heights than the mean sea level.

6. A system for utilizing the wave energy of the sea/ocean to generate electric power comprising:

- placing the modified Archimedes screw at a suitable angle with respect to the flow of the incoming sea waves whereby said modified Archimedes screw will rotate by itself with ease utilizing maximum energy available in the sea/tidal waves;

- turbines connected with electric generator at the predetermined positions to receive the sea water from the said modified Archimedes Screw to generate electricity.

7. The system as claimed in claim 6, wherein said modified Archimedes screw is placed in a position such as vertically, in parallel or perpendicularly to the flow of the incoming sea waves and/or either in a inclined position or in horizontal position with respect to the flow of the incoming sea waves whereby said modified Archimedes screw will rotate by itself with ease utilizing maximum energy available in the sea /tidal waves

8. The system as claimed in claim 6, wherein modified Archimedes screw is placed in such a way that before one sea wave / tidal wave has passed over / through it another sea wave / tidal wave has begun to pass over / through the modified Archimedes screw.

9. The system as claimed in claim 6, wherein seawater is optionally stored at a height in suitable tanks, before being allowed to flow back to the sea through turbines connected with electric generator.

10. The process for utilizing the sea wave / tidal wave energy of the sea / ocean to generate electric power comprising:

- allowing the waves of the sea / tidal waves of the ocean to pass over / through the modified Archimedes screw causing it to rotate thus raising the level of the sea water so as to convert the potential energy of the sea waves / tidal waves into the kinetic energy;

- wind energy as well as solar energy is alternatively used to assist in the rotation of yet another Archimedes Screw, or a pump, for pumping the raised seawater to a much higher height. After raising the potential energy of the pumped seawater, it is released to be used as a kinetic energy to rotate a KAPLAN / FRANCIS type of turbine connected to an appropriate electrical generator;

- passing the sea water from the said the modified Archimedes screw into the turbines connected to the electricity generators to convert the kinetic energy now present in the raised seawater in to electric energy.